A dispersant, a flame retardant composition containing the same, and use thereof

Abstract

The application discloses a dispersant, a flame retardant composition containing the dispersant and application of the flame retardant composition; the dispersant is prepared by dissolving DOPO-AM, a styrene maleic anhydride copolymer, polyethylene glycol monomethyl ether and a catalyst in a solvent, insulating air and reacting at a reflux temperature and then neutralizing; the flame retardant composition comprises the following components in the following proportions: 12-25% of the dispersant, 12-32% of a clay mineral, 40-64% of DDPS and 2-9% of black phosphorus. The dispersant adopts styrene maleic anhydride grafting AM, DOPO and MPEG; the MPEG improves the dispersing performance of the dispersant, and the DOPO makes the dispersant have flame retardant performance; the flame retardant composition has the advantages of self-dispersing, good stability and high flame retardant efficiency, and can make the flame-retardant viscose fiber have the characteristics of high fiber strength and good flame-retardant effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of flame retardant technology, in particular to a dispersant, a flame retardant composition containing the dispersant and the application of the flame retardant composition in flame-retardant viscose fibers. BACKGROUND

[0002] Viscose fiber, also known as viscose, is a major variety of man-made fiber and the second largest variety of chemical fiber in China. Due to its flammability, the use of viscose fiber is limited. Flame retardant 2.2-dioxo【5.5-dimethyl-1.3.2-dioxaphosphorinane】2.2-disulfide (DDPS) is a new type of organic phosphorus halogen-free flame retardant. DDPS contains phosphorus and sulfur flame-retardant elements and is a commonly used flame retardant for viscose fibers. Flame-retardant viscose fibers can be prepared by blending and spinning using this flame retardant. However, the interface compatibility between the hydrophobic DDPS flame retardant and the cellulose macromolecule is poor, and there is no strong interface interaction between the two. Therefore, after washing or abrasion, DDPS is easily lost from the viscose fiber, affecting the flame-retardant durability. On the other hand, the flame-retardant efficiency of DDPS is poor, and the addition amount is large, which makes the physical and mechanical properties of the flame-retardant viscose fiber deteriorate with the addition of DDPS.

[0003] To improve the flame-retardant efficiency of flame-retardant viscose fibers, some technicians consider using the synergistic effect of multiple flame-retardant elements and introducing nitrogen flame-retardant elements to construct a DDPS-based intumescent flame-retardant system. For example, CN115161036A discloses an environmentally friendly flame retardant and a preparation method thereof. The preparation raw materials of the environmentally friendly flame retardant include a silicon-nitrogen flame retardant, a dithio pyrophosphoric acid ester, a wetting dispersant, and water. The silicon-nitrogen flame retardant is prepared by reacting a silane coupling agent and a nitrogen-containing intermediate. In “Synergistic flame-retardant modification of dithio pyrophosphoric acid ester / viscose fiber and its performance”, Xiong Yonghui et al. selected magnesium aluminum silicate (MAS) as a synergistic flame retardant for DDPS to prepare MAS / DDPS / VF flame-retardant fibers through a wet spinning process to solve the problem of poor flame-retardant efficiency of dithio pyrophosphoric acid ester / viscose fiber (DDPS / VF). In “Preparation and performance of sol-gel modified flame-retardant viscose fiber”, Ma Junzhi et al. used tetraethyl orthosilicate (TEOS) to modify the surface of VF / DDPS fibers through a sol-gel method to improve the flame-retardant performance of viscose / dithio pyrophosphoric acid ester (VF / DDPS) fibers, obtaining flame-retardant viscose fibers (VF / DDPS / TEOS).

[0004] Styrene maleic anhydride copolymer SMA is obtained by free radical polymerization of styrene and maleic anhydride, and its structure contains both styrene and maleic anhydride units with different properties, and maleic anhydride can be further modified to introduce other functional groups. It is widely used in composite processing and special chemicals such as water-based pigment systems. SMA copolymer can be used in water-based pigment system because the benzene ring in its molecule can form a bond with the pigment molecule, and the hydrolysis forms a solvated chain and maleic acid; wherein, maleic acid has a steric hindrance effect. Unmodified SMA not only has poor heat resistance and weather resistance, but also has large particles and unstable properties, and is prone to flocculation. Chemical modification of SMA is the simplest and most direct method to improve its performance and expand its application field. The modified styrene-maleic anhydride molecule has better flexibility, hydrophilicity and lipophilicity, heat resistance and stability. For example, CN109776710A discloses a water-based pigment dispersant containing styrene-maleic anhydride structure and graft modification and a preparation method thereof. The four monomers of styrene, styrene derivative, maleic anhydride and acrylic acid derivative are free radical copolymerized to form a block copolymer, and then the block copolymer is grafted with a grafting modifier to prepare a water-based pigment dispersant containing styrene-maleic anhydride structure and graft modification. The dispersant has large steric hindrance and strong anchoring capacity, can stably disperse pigments in water-based color paste application, has relatively strong color strength, and has good storage stability. At present, there is no report on improving the dispersion performance of DDPS-based flame retardant by using modified SMA. SUMMARY

[0005] To solve the above technical problems, the purpose of the present application is to provide a dispersant, a flame retardant composition containing the dispersant and the application thereof. The flame retardant composition of the present application has the advantages of self-dispersing, good stability and high flame retardant efficiency, and is applied to flame-retardant viscose fibers, which can make the flame-retardant viscose fibers have the characteristics of high fiber strength and good flame-retardant effect.

[0006] To achieve the above technical purpose and achieve the above technical effect, the present application realizes the following technical scheme:

[0007] A dispersant, the molecular structure formula of which is:

[0008]

[0009] Wherein, M is an alkali metal element, x:y:z=(0-1):(3-7):(1-7).

[0010] In order to improve the dispersion performance of the dispersant, the molecular weight of the dispersant is preferably 5000-30000, and further preferably 7000-16000.

[0011] The dispersing agent has poor dispersing performance and flame retardant performance with the increase of x value, i.e. the grafting amount of DOPO and MPEG groups is reduced, and x:y:z is further preferably (0-0.5):(3-7):(1-7).

[0012] The value of m in the molecular structure is determined by the grafted polyethylene glycol monomethyl ether group and varies with the molecular weight of the grafted MPEG. The polyethylene glycol monomethyl ether is selected from one of MPEG-200, MPEG-350, MPEG-400, MPEG-450, MPEG-500, MPEG-750, MPEG-1000, MPEG-1200, MPEG-1500, and MPEG-2000.

[0013] The alkali metal element is preferably sodium or potassium.

[0014] The application further provides a preparation method of the dispersing agent, specifically: dissolving DOPO-AM, styrene maleic anhydride copolymer (SMA), polyethylene glycol monomethyl ether (MPEG), and a catalyst in a solvent, reacting under reflux temperature in an air-tight manner; after the reaction is completed, the reaction solution is cooled, then neutralized to neutral, and then filtered, washed, and dried to obtain the dispersing agent.

[0015] DOPO-AM is the addition product of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide DOPO and acrylamide AM, and the reaction route is shown in formula (1). The specific synthesis process is prior art and will not be described here.

[0016]

[0017] The ratio of the reactants DOPO, AM, MPEG, and SMA is selected according to the molecular weight of the required dispersing agent and the grafting ratio of each group. In order to balance the reaction rate and side reactions, the reaction temperature is preferably 85-95°C. The molar ratio of styrene and maleic anhydride in the styrene maleic anhydride copolymer is 1:1, which can be synthesized by classical free radical copolymerization, and there are many related products on the market, which can be selected. The polyethylene glycol monomethyl ether is selected from one of MPEG-200, MPEG-350, MPEG-400, MPEG-450, MPEG-500, MPEG-750, MPEG-1000, MPEG-1200, MPEG-1500, and MPEG-2000. The catalyst is a proton acid catalyst required for anhydride esterification reaction, such as p-toluenesulfonic acid, benzene sulfonic acid, boron trifluoride (BF3), aluminum trichloride (AlCl3), zinc dichloride (ZnCl2), macroporous resin of sulfonic acid type (R-SO3H) such as D72, D61 type, etc. The molar ratio of the catalyst to the total amount of the reactants is preferably 0.001-0.05.

[0018] The solvent can be selected from ketone solvents, ester solvents or other solvents; the ketone solvent can be acetone, butanone or methyl isobutyl ketone; the ester solvent can be ethyl acetate, butyl acetate or propyl acetate; and the other solvent can be tetrahydrofuran, N,N-dimethylformamide or 1,4-dioxane.

[0019] The application further discloses a flame retardant composition containing the dispersant; the flame retardant composition contains the following components in the following proportions based on the total mass of the flame retardant composition.

[0020]

[0021] In order to balance dispersibility and flame retardant performance, the proportions of the components in the flame retardant composition are further preferably as follows based on the total mass of the flame retardant composition.

[0022]

[0023] The clay mineral is a kind of hydrous silicate or aluminosilicate mineral, and in the chemical composition thereof, in addition to water, a large amount of SiO2 and Al2O3 are generally contained, and a certain amount of Fe2O3, MgO and a small amount of K2O, Na2O and CaO are also contained; common clay minerals include talcum powder, attapulgite, montmorillonite and sepiolite.

[0024] In the flame retardant composition of the application, DDPS (dithiopyrophosphoric acid ester) is used as a main flame retardant, black phosphorus and a clay mineral are used as flame retardant aids, and the dispersant has flame retardant performance due to the grafting of DOPO, and the synergistic effect of the multiple flame-retardant elements of silicon, phosphorus and sulfur improves the flame-retardant efficiency.

[0025] The preparation method of the flame retardant composition is as follows: DDPS, a clay mineral, black phosphorus and a dispersant are dispersed and ground in deionized water, and then a powder is prepared by spray drying; the dispersion condition is generally set as a speed of 1000-2000 r / min and a time of 0.3-2 hours; the grinding condition is generally set as a speed of 2000-4000 r / min and a time of 0.5-3 hours; and the spray drying process is generally set as a temperature of 100-140 DEG C.

[0026] The flame retardant composition of the application exists in the form of a powder during storage, and can prevent the hydrolysis of black phosphorus and the coarsening of the clay mineral, thereby prolonging the shelf life of the product; and when used, the flame retardant composition can be directly dispersed in water and then wet-spun with viscose fibers.

[0027] The application further provides the application of the flame retardant composition, specifically, the flame retardant composition is dispersed and then wet-spun with viscose fibers to prepare flame-retardant viscose fibers.

[0028] The application further provides a flame-retardant viscose fiber prepared by wet-spinning the flame retardant composition with viscose fibers.

[0029] The beneficial effects of this invention are:

[0030] 1. The dispersant of the present invention is made of styrene-maleic anhydride grafted with AM, DOPO and MPEG; MPEG improves the dispersing performance of the dispersant, and DOPO gives the dispersant flame retardant properties;

[0031] 2. The flame retardant composition of the present invention is composed of DDPS, black phosphorus, clay minerals, and a dispersant grafted with styrene maleic anhydride, namely AM, DOPO, and MPEG. The dispersant can improve the self-dispersing ability of the flame retardant during application, giving it self-dispersing characteristics. Moreover, the DOPO grafted onto the dispersant, in combination with black phosphorus, DDPS, and clay minerals, increases the phosphorus content in the flame retardant, forming a synergistic effect of silicon, phosphorus, and sulfur as multiple flame retardant elements, thereby improving the flame retardant efficiency of the flame retardant composition.

[0032] 3. The clay minerals in the flame retardant composition of the present invention readily form hydrogen bonds with cellulose fibers, thereby enhancing the strength of the flame-retardant viscose fiber made using the flame retardant composition;

[0033] 4. The flame retardant composition of the present invention utilizes self-dispersibility technology to form a storage-resistant and easily dispersible flame retardant powder, thereby avoiding the hydrolysis of black phosphorus and the coarsening of clay minerals. It has good stability and can be directly dispersed with water during application.

[0034] 5. The flame retardant composition of the present invention has the advantages of self-dispersion, good stability and high flame retardant efficiency. When applied to the preparation of flame retardant viscose fibers, the obtained viscose fibers can have the characteristics of high fiber strength and good flame retardant effect. Attached Figure Description

[0035] Figure 1 Infrared spectrum of the dispersant (PSMA-MPEG-DOPO-AM).

[0036] Figure 2 Infrared spectrum of dispersant (PSMA-MPEG). Detailed Implementation

[0037] The technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] The substances used in the examples and comparative examples are, unless otherwise stated, from commercially available products. The styrene maleic anhydride copolymer is synthesized by free radical copolymerization; DOPO-AM is synthesized according to the section 2.2 in Effect of sulfur in different valence on flame retardance of epoxy resin for light emitting diode by Chaoyun Luo et al.

[0039] Synthesis of dispersant (PSMA-MPEG-DOPO-AM)

[0040] SMA, MPEG1000, DOPO-AM, p-toluenesulfonic acid, tetrahydrofuran are added into a four-necked flask equipped with an electric stirrer, thermometer, ball condenser and nitrogen inlet tube in the molar ratio (calculated by the moles of anhydride in the polystyrene maleic anhydride) of 1:0.6:0.35:0.005:4, heated to reflux temperature under stirring at 200 r / min and nitrogen protection for 24 hours. After cooling to room temperature, neutralize to neutral with 10 wt% sodium hydroxide ethanol solution, filter and wash with anhydrous ethanol for three times. Put the filter cake into a vacuum oven, dry at 60°C to constant weight, get the dispersant (PSMA-MPEG-DOPO-AM). The general molecular structure is shown in formula (2), wherein x:y:z=0.5:6:3.5, the Mw is 16827 and the polydispersity coefficient is 1.27 measured by GPC.

[0041]

[0042] The infrared spectrum of the dispersant is measured by Bruker ALPHA series Fourier transform infrared spectrometer, as shown in Figure 1 , wherein the peak at 1453.26 cm -1 is the stretching vibration peak of benzene ring skeleton, the peak at 948.11 cm -1 is the absorption peak of P-O-C, the peak at 1098.02 cm -1 is the C-O-C absorption peak after esterification, the peak at 1637.5 cm -1 is the absorption peak of carbonyl group, the peak at 1582.20 cm -1 and the peak at 1295.94 cm -1 are the absorption peaks of imide. It shows that SMA is successfully grafted with AM, DOPO and MPEG.

[0043] Synthesis of dispersant (PSMA-MPEG)

[0044] The dispersant (PSMA-MPEG) was prepared by referring to the synthesis process of the dispersant (PSMA-MPEG-DOPO-AM), and its general molecular structure formula is (3):

[0045]

[0046] Where x1:y1 = 1:19; the value of m1 is determined by the grafted polyethylene glycol monomethyl ether group and varies with the molecular weight of the grafted MPEG; the polyethylene glycol monomethyl ether used in this comparative example is MPEG1000. GPC measured Mw to be 17116 and polydispersity index to be 1.20.

[0047] The infrared spectrum of the dispersant (PSMA-MPEG) was measured using a Bruker ALPHA series Fourier transform infrared spectrometer, as shown below. Figure 2 As shown, 1454.36cm -1 The peak at 1097.74 cm⁻¹ represents the stretching vibration peak of the benzene ring skeleton. -1 The peak at that point is the COC absorption peak after esterification, indicating that SMA was successfully grafted with MPEG.

[0048] Example 1

[0049] 147g of flame retardant DDPS, 41g of talc, 12g of black phosphorus and 30g of dispersant (PSMA-MPEG-DOPO-AM) were added to 770g of deionized water and stirred and dispersed at 1500r / min for 30 minutes. The dispersed material was then placed in a grinder and ground at 3000r / min for 3 hours to obtain a water-based dispersion system for the flame retardant. After spray drying at 120℃, an easily dispersible flame retardant composition was obtained.

[0050] Example 2

[0051] 120g of flame retardant DDPS, 60g of talc, 20g of black phosphorus and 30g of dispersant (PSMA-MPEG-DOPO-AM) were added to 770g of deionized water and stirred and dispersed at 1500r / min for 30 minutes. The dispersed material was then placed in a grinder and ground at 3000r / min for 3 hours to obtain a water-based dispersion system of flame retardant. After spray drying at 120℃, an easily dispersible flame retardant composition was obtained.

[0052] Example 3

[0053] Take 147 grams of flame retardant DDPS, 28 grams of talc, 12 grams of black phosphorus and 44 grams of dispersant (PSMA-MPEG-DOPO-AM) into 1235 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based flame retardant dispersion system. After spray drying at 120°C, an easily dispersible flame retardant composition is obtained.

[0054] Example 4

[0055] Take 120 grams of flame retardant DDPS, 55 grams of talc, 12 grams of black phosphorus and 44 grams of dispersant (PSMA-MPEG-DOPO-AM) into 1235 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based flame retardant dispersion system. After spray drying at 120°C, an easily dispersible flame retardant composition is obtained.

[0056] Example 5

[0057] Take 92 grams of flame retardant DDPS, 60 grams of talc, 20 grams of black phosphorus and 58 grams of dispersant (PSMA-MPEG-DOPO-AM) into 1703 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based flame retardant dispersion system. After spray drying at 120°C, an easily dispersible flame retardant composition is obtained.

[0058] Comparative Example 1

[0059] Take 200 grams of flame retardant DDPS and 30 grams of dispersant (PSMA-MPEG-DOPO-AM) into 770 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based flame retardant dispersion system.

[0060] Comparative Example 2

[0061] Take 120 grams of flame retardant DDPS, 60 grams of talc, 20 grams of black phosphorus and 30 grams of dispersant (PSMA-MPEG-DOPO-AM) into 770 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based flame retardant dispersion system.

[0062] Comparative Example 3

[0063] Take 120 grams of flame retardant DDPS, 20 grams of black phosphorus and 21 grams of dispersant (PSMA-MPEG-DOPO-AM) into 539 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based dispersion system of the flame retardant. Spray drying at 120°C to prepare a flame retardant composition.

[0064] Comparative Example 4

[0065] Take 120 grams of flame retardant DDPS, 60 grams of talc and 24 grams of dispersant (PSMA-MPEG-DOPO-AM) into 596 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based dispersion system of the flame retardant. Spray drying at 120°C to prepare a flame retardant composition.

[0066] Comparative Example 5

[0067] Take 120 grams of flame retardant DDPS, 60 grams of talc, 20 grams of black phosphorus and 30 grams of dispersant (PSMAP-MPEG) into 770 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based dispersion system of the flame retardant. Spray drying at 120°C to prepare a flame retardant composition.

[0068] Comparative Example 6

[0069] Take 120 grams of flame retardant DDPS, 60 grams of talc, 20 grams of black phosphorus and 30 grams of dispersant octadecylamine polyoxyethylene ether into 770 grams of deionized water, stirring and dispersing at 1500 r / min for 30 minutes, then placing the dispersed material in a grinder at 3000 r / min for 3 hours to prepare a water-based dispersion system of the flame retardant. Spray drying at 120°C to prepare a flame retardant composition.

[0070] Fiber performance and flame retardant particle size determination:

[0071] The flame retardant and viscose fiber spinning solution in the examples and comparative examples were mixed at 20% of the mass of the flame retardant to the mass of the viscose fiber, and then the flame retardant and viscose fiber spinning solution were wet-spun to prepare flame-retardant viscose fiber. The oxygen index of the flame-retardant viscose fiber was determined according to FZ / T50016-2011 "Test Method for Flame Retardant Property of Viscose Staple Fiber - Oxygen Index Method". The dry and wet breaking strength of the flame-retardant viscose fiber was determined according to GB / T 14337-2008 "Test Method for Tensile Property of Chemical Fiber Staple Fiber". The dispersion particle size of the flame retardant composition and the particle size of the flame retardant slurry were determined by Zetasizer Nano ZS90 Nanoparticle Size Analyzer. The determination results are shown in Table 1.

[0072] Table 1

[0073]

[0074]

[0075] Note: The flame retardant slurry prepared in Comparative Example 1 and Comparative Example 2 was obviously stratified after 30 days, and the particle size was meaningless, so it was not determined.

[0076] In Table 1, it can be seen from the comparison between Example 2 and Comparative Example 5 that: the flame retardant composition prepared by using SMA modified by organic phosphorus has slightly larger particle size compared with the flame retardant composition prepared by using SMA not modified by organic phosphorus, and the mechanical properties of the fibers prepared therefrom are similar, but the flame retardant efficiency of Example 2 is enhanced. It can be seen from Comparative Examples 1 and 2 that the flame retardant composition of the present application is not suitable for storage in the form of slurry. The self-dispersed particle size of the powder of the flame retardant composition of the present application has little change compared with the self-dispersed particle size after 30 days, and the stability is strong.

[0077] The above description is only an embodiment of the present application, and does not limit the patent scope of the present application, and any modification or equivalent transformation made by using the content of the specification and drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A flame retardant composition, characterized in that, Based on the total mass of the flame retardant composition, the flame retardant composition comprises the following components in the following proportions: Dispersant 12%–25%; Clay minerals: 12%–32%; DDPS 40%~64%; Black phosphorus 2%–9%; The molecular structural formula of the dispersant is: ； Where M is an alkali metal element, x:y:z = (0~1):(3~7):(1~7); The molecular weight of the dispersant is 5000 to 30000.

2. The flame retardant composition according to claim 1, characterized in that, x: y: z= (0~0.5): (3~7): (1~7).

3. The flame retardant composition according to claim 1, characterized in that, The value of m is determined by the grafted polyethylene glycol monomethyl ether group.

4. The flame retardant composition according to claim 1, characterized in that, The dispersant is prepared by dissolving DOPO-AM, styrene-maleic anhydride copolymer, polyethylene glycol monomethyl ether and catalyst in a solvent, isolating them from air, reacting them at reflux temperature, and then neutralizing them to prepare the dispersant.

5. The flame retardant composition according to claim 4, characterized in that, The polyethylene glycol monomethyl ether is selected from one of MPEG-200, MPEG-350, MPEG-400, MPEG-450, MPEG-500, MPEG-750, MPEG-1000, MPEG-1200, MPEG-1500, and MPEG-2000.

6. A method for preparing a flame retardant composition according to any one of claims 1 to 5, characterized in that, DDPS, clay minerals, black phosphorus, and dispersant are dispersed and ground in deionized water, and then spray-dried to obtain a powder.

7. The application of a flame retardant composition according to any one of claims 1 to 5, characterized in that, Flame-retardant viscose fibers are prepared by wet co-spinning a flame retardant composition with viscose fibers.

8. A flame-retardant viscose fiber, characterized in that, It is prepared by wet co-spinning of the flame retardant composition according to any one of claims 1 to 5 with viscose fiber.

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