A phosphorus-containing macromolecular charring agent, its preparation method and application

Abstract

The present invention belongs to the technical field of flame retardants, and relates to a phosphorus-containing macromolecular charring agent, its preparation method and application. Specifically, a phosphorus-containing macromolecular charring agent is first prepared by an esterification reaction of a dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl) isocyanuric acid ester, a catalyst, and sodium bicarbonate; then the phosphorus-containing macromolecular charring agent is melt-blended with a polyester resin, glass fiber, and aluminum phosphite in a certain proportion to obtain a flame-retardant polyester resin composite material. The flame-retardant polyester composite material prepared by the present invention significantly improves the flame-retardant performance of the polyester material through the synergistic effect of the phosphorus-containing macromolecular charring agent and aluminum phosphite, and effectively overcomes the wick effect of the glass fiber-reinforced polyester material. In addition, the composite material not only has excellent flame-retardant effect, but also has less loss of mechanical properties and a wide range of applications.

Description

Technical Field

[0001] The present invention belongs to the technical field of flame retardants, and relates to a phosphorus-containing macromolecular charring agent, a preparation method thereof, and an application thereof. Background Art

[0002] Polyester resin is one of the most commonly used thermoplastic resins at present. With its advantages of easy processing and molding, good acid and alkali resistance, high chemical stability, etc., it has been widely used in fields such as plastic packaging, synthetic fibers, and automotive parts. However, the polyester molecular structure contains a large amount of C, H, and O elements, and the ignition point is relatively low, resulting in its extremely easy combustion and rapid spread of fire, and poor flame retardant performance. Therefore, the flame retardant modification of polyester has become the focus of attention of researchers.

[0003] In the application of polyester materials, glass fiber-reinforced polyester composites are favored due to their excellent mechanical properties (such as strength, rigidity, etc.). However, the introduction of glass fibers brings significant wick effect problems. The wick effect refers to the phenomenon that during combustion, the polyester matrix is heated and melted, and the melt migrates rapidly along the surface of the glass fiber to the high-temperature area (flame) under the action of surface tension and capillary action, forming a path similar to the transportation of wax oil along the wick during candle burning. This phenomenon leads to the rapid spread of the flame and a significant reduction in the flame retardant effect. Although glass fibers can significantly improve the mechanical properties of materials, the wick effect caused by them makes it difficult for traditional flame retardants to meet the flame retardant requirements of glass fiber-reinforced polyester composites. Therefore, developing an efficient flame retardant that can not only effectively improve the flame retardant performance of polyester materials but also overcome the wick effect of the glass fiber-reinforced system is still an important research direction in the current flame retardant field.

[0004] DOPO and its derivatives are a class of commonly used flame retardants. For example, in Document 1 (Synthesis of DOPO-based polyester polyols and P / N-containing chain extenders and their application in polyurethane elastomers [D]. Fujian Normal University, 2020.), DOPO was used to react with maleic anhydride (MA) to prepare a DOPO derivative DOPO-MA, and then it was reacted with diethylene glycol, ethylene glycol, and adipic acid to synthesize polyester polyols, and finally reacted with 1,3,5-tris(2-hydroxyethyl) isocyanurate (THEIC) to prepare a macromolecular flame retardant. This flame retardant shows good flame retardant effects in polyurethanes, but its reaction system is complex, the molecular structure of the product is difficult to control, and the thermal decomposition temperature is relatively low (the 5% thermal weight loss temperature is 281 °C), which cannot meet the requirements of polyester processing conditions, especially it is difficult to overcome the wick effect in the glass fiber-reinforced polyester system.

[0005] Reference 2 (A new halogen-free flame retardant based on 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide for epoxy resins and their carbon fiber composites for the automotive and aviation industries[J]. Macromolecular Materials and Engineering, 2011, 296 (1): 14-30.) designed and prepared a macromolecule containing DOPO and 1,3,5-tris(2-hydroxyethyl)isocyanurate structures, and applied it in epoxy resins, effectively improving the flame retardancy of the materials. However, the molecular weight of this molecule is relatively low, and it is difficult to form a carbon skeleton network during combustion, resulting in poor flame retardancy in glass fiber-reinforced polyester.)

[0006] Generally speaking, the application of DOPO derivative flame retardants in polyester systems, especially in glass fiber-reinforced polyester systems, generally has the following problems: (1) The reaction system of DOPO derivative flame retardants is complex, and the molecular structure is difficult to control; (2) The molecular weight of DOPO derivative flame retardants is not high, and the carbonization effect during the flame retardancy process is limited; (3) The thermal decomposition temperature of DOPO derivative flame retardants is relatively low, making it difficult to meet the processing requirements of polyester; (4) Adding DOPO derivative flame retardants results in severe thermal degradation of polyester during processing, and the mechanical properties decrease significantly; (5) Adding DOPO derivative flame retardants, the wick effect is significant during the combustion of glass fiber-reinforced polyester materials, and the flame retardancy effect is not good. Therefore, although DOPO-based flame retardants show certain flame retardancy effects in some fields, their application in polyester materials still needs to be further optimized and improved.) Summary of the Invention

[0007] The purpose of the present invention is to solve the deficiencies in the prior art and propose a phosphorus-containing macromolecular charring agent, its preparation method and application.)

[0008] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A phosphorus-containing macromolecular charring agent has the following structural formula:

[0010] ;

[0011] In the formula, between -C=O- and -COO- It is composed of 2 - 7 chain segments, and each chain segment is independently selected from one of the esterification reaction product chain segments of 1,3,5 - tris(2 - hydroxyethyl) isocyanurate and dicarboxyl DOPO derivative and the esterification reaction product chain segment of 1,3,5 - tris(2 - hydroxyethyl) isocyanurate and succinic acid;

[0012] The structural formula of the dicarboxyl DOPO derivative is as follows:

[0013] 。

[0014] As a preferred technical solution:

[0015] For a phosphorus - containing macromolecular char - forming agent as described above, the 5% thermal weight - loss temperature of the phosphorus - containing macromolecular char - forming agent ≥ 300 °C, the molecular weight is 8000 - 20000, the phosphorus element content is 5000 - 10000 ppm, the nitrogen element content is 3000 - 5000 ppm, and the acid value is 4.1 - 9.9 mg KOH / g.

[0016] The present invention also provides a method for preparing a phosphorus - containing macromolecular char - forming agent as described in any one of the above, and the reaction equation is as Figure 4 shown, including the following steps:

[0017] (a) Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5 - tris(2 - hydroxyethyl) isocyanurate evenly and then melt them at 150 - 220 °C;

[0018] (b) After adding a first catalyst to the system in step (a), stir and react for 2 - 4 h, and continuously evacuate during this process to remove the water generated by the reaction;

[0019] In the present invention, adding the first catalyst after melting is for two reasons. On the one hand, it is to prevent the first catalyst from sticking to the inner wall of the reaction vessel with the reactants during the melting process and being unable to participate in the subsequent reaction. On the other hand, it is to prevent the first catalyst from dehydrating the reactants in advance and causing losses;

[0020] (c) After adding sodium bicarbonate to the system in step (b), continue to stir and react for 0.5 - 2 h, and obtain the phosphorus - containing macromolecular char - forming agent after post - treatment (natural cooling, washing, drying).

[0021] As a preferred technical solution:

[0022] For the method as described above, in step (a), the reaction equation for preparing the dicarboxyl DOPO derivative is as Figure 1 shown, and the specific preparation steps are as follows:

[0023] (i) Dissolve DOPO and glyoxal in a solvent (toluene, absolute ethanol, acetonitrile, xylene, absolute methanol, acetone, dimethyl sulfoxide or N,N-dimethylformamide), reflux at 90 - 110 °C for 3 h, then filter, wash and dry to obtain a white product;

[0024] (ii) Uniformly mix the product obtained in step (i) with adipic acid and melt at 180 - 220 °C;

[0025] (iii) Add a second catalyst to the system in step (ii), stir and react for 3 - 5 h. During this process, continuously introduce nitrogen to remove the water generated by the reaction. After post-treatment (washing, drying), the dicarboxyl DOPO derivative is obtained;

[0026] In the present invention, adding the second catalyst after melting is for two reasons. On the one hand, it is to prevent the second catalyst from sticking to the inner wall of the reaction vessel with the reactants during the melting process and being unable to participate in the subsequent reaction. On the other hand, it is to prevent the second catalyst from dehydrating the reactants in advance and causing losses.

[0027] In the method as described above, during the preparation of the dicarboxyl DOPO derivative, the molar ratio of DOPO to glyoxal is 1.5 - 10:1; the molar ratio of the product obtained in step (i) to adipic acid is 1:1.5 - 10; the second catalyst is p-toluenesulfonic acid or zinc acetate, and the mass addition amount of the second catalyst is 0.1 - 1% of the total mass addition amount of DOPO, glyoxal and adipic acid.

[0028] In the method as described above, during the preparation of the phosphorus-containing macromolecular charring agent, the molar ratio of the dicarboxyl DOPO derivative, succinic acid to 1,3,5-tris(2-hydroxyethyl)isocyanurate is 1 - 5:1:1 - 5; the first catalyst is concentrated sulfuric acid, p-toluenesulfonic acid or phosphoric acid, and the mass addition amount of the first catalyst is 0.1 - 1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate; the mass addition amount of sodium bicarbonate is 0.1 - 5% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl)isocyanurate and sodium bicarbonate.

[0029] The present invention also provides a flame-retardant glass fiber reinforced polyester resin composition containing a phosphorus-containing macromolecular charring agent as described in any one of the above. By weight, it is composed of 60 - 80 parts of polyester resin, 15 - 30 parts of glass fiber, 2.5 - 4 parts of aluminum phosphite, and 5 - 10 parts of phosphorus-containing macromolecular charring agent. There is no crystal water in the aluminum phosphite; the aluminum phosphite used in the present invention (produced by Hunan Meilaiper Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., brand M119-S) has no crystal water and excellent thermal stability, and the 1% thermal weight loss decomposition temperature is greater than 420 °C (TGA, 10 °C / min, N2 ), the residual mass at 800 °C is greater than 95% (TGA, 10 °C / min, N 2 ).

[0030] As a preferred technical solution:

[0031] In a flame-retardant glass fiber-reinforced polyester resin composition as described above, the polyester resin is one or more of polyethylene terephthalate and polybutylene terephthalate; the glass fiber is an E-glass fiber with a length of 1.5 - 5.0 mm; wherein, the glass fiber is used as a reinforcing material to improve the mechanical properties of the material.

[0032] The present invention also provides a flame-retardant polyester composite material, which is prepared by melting and blending a flame-retardant glass fiber-reinforced polyester resin composition as described in any one of the above, followed by cooling, drying, pelletizing, and injection molding in sequence, wherein the temperature of the melt blending is 230 - 280 °C.

[0033] As a preferred technical solution:

[0034] In a flame-retardant polyester composite material as described above, the flame-retardant polyester composite material generates non-flaming melt droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, the limiting oxygen index ≥ 30.5%, the tensile strength is 100 - 150 MPa, the flexural strength is 150 - 180 MPa, and the notched Izod impact strength of the simply supported beam is 7 - 9 KJ / m 2 ;

[0035] Compared with the polyester composite material without adding flame-retardant components, the reduction in the tensile strength, flexural strength, and notched Izod impact strength of the flame-retardant polyester composite material of the present invention is less than 10%. This is because the phosphorus-containing macromolecular charring agent in the flame-retardant polyester composite material has good compatibility with the polyester and has little effect on the mechanical properties of the polyester matrix.

[0036] Principle of the invention:

[0037] I. Regarding problem (1) that the reaction system of the DOPO derivative flame retardant is complex and the molecular structure is difficult to control:

[0038] The present invention first uses a DOPO diol derivative (i.e., the white product in step (i)) to esterify with adipic acid to prepare a dicarboxyl DOPO derivative, and then esterify with 1,3,5-tris(2-hydroxyethyl) isocyanurate to form a macromolecular structure, and finally carry out terminal carboxyl sodium saltification to obtain a phosphorus-containing macromolecular charring agent. In this way, the phosphorus-containing macromolecular charring agent prepared by the method of two-step esterification has a controllable molecular structure, few side reactions, and high product purity.

[0039] 2. Regarding problem (2) that the molecular weight of DOPO derivative flame retardants is not high, and the carbonization effect during the flame retardant process is limited; and problem (3) that the thermal decomposition temperature of DOPO derivative flame retardants is low, which is difficult to meet the requirements of polyester processing:

[0040] The two ends of the dicarboxyl DOPO derivative of the present invention have aliphatic long-chain terminal carboxyl groups with a carbon number of 6, and exhibit extremely high reactivity with 1,3,5-tris(2-hydroxyethyl)isocyanurate. The phosphorus-containing macromolecular carbon-forming agent generated by the reaction has a high molecular weight and forms a three-dimensional network structure. As the esterification reaction proceeds and the molecular weight increases, the steric hindrance effect of the substituent in the molecule is enhanced, and the intermolecular force is also increased, which makes the O=PO bond in the structure of the dicarboxyl DOPO derivative more stable and difficult to break, thereby significantly increasing the thermal decomposition temperature of the phosphorus-containing macromolecular carbon-forming agent.

[0041] 3. Regarding problem (4), adding DOPO derivative flame retardants causes severe thermal degradation of polyester during processing and a significant decrease in mechanical properties:

[0042] The use of conventional DOPO derivatives as flame retardants will lead to aggravated thermal degradation of polyester during processing, thereby significantly reducing its mechanical properties. The present invention finds that the main reason is that conventional DOPO derivatives have a low molecular weight and contain a large number of terminal hydroxyl groups or terminal carboxyl groups, and such groups will promote the hydrolysis reaction of ester bonds in polyester during polyester thermal processing, thereby causing severe thermal degradation. The present invention adds sodium bicarbonate to the system for preparing a phosphorus-containing macromolecular carbonizing agent, replaces the terminal carboxyl group with a sodium salt, and prepares a phosphorus-containing macromolecular carbonizing agent, which effectively reduces the promotion effect of the terminal carboxyl group on thermal degradation during polyester processing.

[0043] IV: Regarding issue (5), adding DOPO derivative flame retardants will cause a significant candle wick effect during the combustion of glass fiber reinforced polyester materials, resulting in poor flame retardant effect:

[0044] Usually, aluminum phosphite is prepared by the reaction of phosphorous acid and aluminum hydroxide, and the chemical formula is Al 2 (HPO 3 ) 3 ·3H 2 O, the theoretical content of crystal water is 15.5%, which cannot be used directly as a flame retardant, and its crystal water is difficult to completely remove by conventional processes. Even if it is dried at 240 ° C for 8 hours under vacuum conditions, the crystal water content remains at around 2-3%, resulting in its 1% thermal decomposition temperature (TGA, 10 ° C / min, N 2)(It) is difficult to exceed 250 °C, so it can only be used as a flame retardant synergist. When conventional aluminum phosphite is added to polyester materials, a large amount of water vapor will be generated during combustion by its crystal water, destroying the compactness of the carbon layer, enabling the continuous exchange of combustion elements (oxygen, combustibles, heat) inside and outside the combustion environment, and thus failing to achieve the flame retardant purpose.

[0045] Conventional phosphorus-containing flame retardants have a relatively low molecular weight and contain a large number of terminal hydroxyl or carboxyl groups, which will promote the hydrolysis reaction of ester bonds in polyester during the hot processing of polyester, failing to achieve the purpose of promoting dripping and effective carbonization. In addition, the carbon formed by conventional phosphorus-containing flame retardants cannot effectively cover the surface of glass fibers, resulting in a significant wick effect and making it difficult to achieve a good flame retardant effect.

[0046] The aluminum phosphite used in the present invention has no crystal water. The phosphorus-containing macromolecular charring agent and this aluminum phosphite play a synergistic role during combustion, promoting the formation of a carbon layer during combustion and greatly improving the density of the carbon layer, thereby achieving the effect of flameless dripping. Specifically: the phosphorus-containing macromolecular charring agent has a three-dimensional network structure, a high molecular weight, and contains a large number of ester bonds and aromatic ring structures in the molecule. It can be dehydrated and catalyzed to form carbon by the generated phosphoric acid during combustion, forming a network carbon skeleton wrapped around the glass fiber, destroying the wick effect of the glass fiber. Subsequently, the highly thermally stable aluminum phosphite migrates and fills inside the carbon skeleton to form a dense phosphorus-containing carbon layer. At the same time, due to the terminal groups of the phosphorus-containing macromolecular charring agent being treated with sodium salts, the sodium salt structure can promote the breakage of molecular chains during the combustion of polyester, accelerating the formation of fine droplets during combustion, thus playing a role in promoting dripping. The dense phosphorus-containing carbon layer covers the surface of the fine droplets and fills inside them, causing the flame to quickly go out during the dripping process of the droplets, forming flameless dripping, thereby achieving the flame retardant effect of UL94-V0 (dripping type V0, not completely non-dripping V0), and effectively overcoming the wick effect caused by glass fibers, realizing the purpose of high flame retardant performance of glass fiber-reinforced polyester resin composites at low addition amounts.

[0047] The present invention melts and blends polyester resin, glass fiber, aluminum phosphite, and phosphorus-containing macromolecular charring agent in a certain proportion to obtain a flame retardant polyester composite material. During the combustion of polyester, the flame retardant aluminum phosphite can promote the dehydration and carbonization of polyester, and the phosphorus-containing macromolecular charring agent provides a carbon source, which can effectively increase the density of the carbon layer. At the same time, the introduced sodium salt structure mainly plays a role in promoting dripping during the combustion of polyester. The above components play a synergistic role during the combustion of polyester, thereby effectively improving the flame retardant performance of the polyester material.

[0048] Beneficial effects:

[0049] The present invention prepares a phosphorus-containing macromolecular charring agent by a two-step esterification method, which has the characteristics of controllable reaction, controllable molecular structure, few side reactions and high product purity. The prepared phosphorus-containing macromolecular charring agent has a high molecular weight, and its 5% thermal weight loss temperature can reach above 300 °C.

[0050] The flame-retardant polyester composite material of the present invention significantly improves the flame-retardant performance of the polyester material through the synergistic effect of the phosphorus-containing macromolecular charring agent and aluminum phosphite. When this material burns, it produces a flameless melt drop, does not ignite absorbent cotton, can meet the UL-94 V-0 test standard with a small addition amount, and effectively overcomes the wick effect of glass fiber-reinforced polyester materials. In addition, this composite material not only has excellent flame-retardant effect, but also has less loss of mechanical properties and has a wide range of applications. Brief Description of the Drawings

[0051] Figure 1 is the reaction equation for preparing the dicarboxyl DOPO derivative of the present invention;

[0052] Figure 2 is the infrared spectrum of the dicarboxyl DOPO derivative prepared in Example 1 of the present invention;

[0053] Figure 3 is the 1H NMR spectrum of the dicarboxyl DOPO derivative prepared in Example 1 of the present invention;

[0054] Figure 4 is the reaction equation for preparing the phosphorus-containing macromolecular charring agent of the present invention;

[0055] Figure 5 is the infrared spectrum of the phosphorus-containing macromolecular charring agent prepared in Example 1 of the present invention;

[0056] Figure 6 is the 1H NMR spectrum of the phosphorus-containing macromolecular charring agent prepared in Example 1 of the present invention, where 7-8.5 ppm is the chemical shift of the hydrogen on the DOPO aromatic ring structure, 4-5 ppm is the chemical shift of the hydrogen on the methylene and the C in the C-P bond in 1,3,5-tris(2-hydroxyethyl)isocyanurate, and 1-3 ppm is the chemical shift of the hydrogen on the methylene in adipic acid and succinic acid. Detailed Description of the Invention

[0057] 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 not 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 also fall within the scope defined by the appended claims of this application.

[0058] The detection methods for the relevant performance indicators in the following examples and comparative examples:

[0059] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent: Tested in accordance with GB / T 33047.1-2016 Plastics - Thermogravimetry (TG) of polymers - Part 1: General principles;

[0060] The molecular weight of the phosphorus-containing macromolecular charring agent: Tested in accordance with GB / T 36214.1-2018 Plastics - Determination of the average molecular weight and molecular weight distribution of polymers by size exclusion chromatography - Part 1: General principles;

[0061] The phosphorus element content of the phosphorus-containing macromolecular charring agent: Tested in accordance with JY / T 015-1996 General rules for inductively coupled plasma atomic emission spectrometry;

[0062] The nitrogen element content of the phosphorus-containing macromolecular charring agent: Tested in accordance with ASTM D5291-21 Standard test method for carbon, hydrogen, and nitrogen in petroleum products and lubricants (element analyzer method);

[0063] The acid value of the phosphorus-containing macromolecular charring agent: Tested in accordance with GB / T 2895-2008 Plastics - Polyester resins - Determination of partial acid value and total acid value;

[0064] The limiting oxygen index of the flame-retardant polyester composite material: Tested in accordance with GB / T 2406.2-2009 Plastics - Determination of burning behavior by the oxygen index - Part 2: Room temperature test;

[0065] The tensile strength of the flame-retardant polyester composite material: Tested in accordance with GB / T 1040.1-2018 Plastics - Determination of tensile properties - Part 1: General principles;

[0066] The flexural strength of the flame-retardant polyester composite material: Tested in accordance with GB / T 9341-2008 Plastics - Determination of flexural properties;

[0067] The notched Izod impact strength of the flame-retardant polyester composite material: Tested in accordance with GB / T 1043.1-2008 Plastics - Determination of Izod impact strength - Part 1: Non-instrumented impact test;

[0068] Example 1

[0069] A preparation method of a phosphorus-containing macromolecular charring agent, the specific steps are as follows:

[0070] (1) Raw material preparation:

[0071] DOPO;

[0072] Glyoxal;

[0073] Adipic acid;

[0074] Succinic acid;

[0075] 1,3,5-Tris(2-hydroxyethyl)isocyanuric acid ester;

[0076] Sodium bicarbonate;

[0077] First catalyst: Concentrated sulfuric acid (mass fraction 98%);

[0078] Second catalyst: p-Toluenesulfonic acid;

[0079] Solvent: Toluene;

[0080] (2) Preparation of dicarboxyl DOPO derivative:

[0081] (2.1) Dissolve DOPO and glyoxal in the solvent, reflux at 100 °C for 3 h, then filter, wash and dry to obtain a white product;

[0082] Among them, the molar ratio of DOPO to glyoxal is 2:1;

[0083] (2.2) Mix the product obtained in step (2.1) with adipic acid evenly and melt at 180 °C;

[0084] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:1.5;

[0085] (2.3) Add the second catalyst to the system of step (2.2) (the mass addition amount of the second catalyst is 1% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 3 h, continuously introduce nitrogen during this process to remove the water generated by the reaction, and obtain the dicarboxyl DOPO derivative after washing and drying;

[0086] The prepared dicarboxyl DOPO derivative has the following structural formula:

[0087] ;

[0088] The infrared spectrum and 1H NMR spectrum of this dicarboxyl DOPO derivative are respectively as Figure 2 , Figure 3 shown;

[0089] (3) Preparation of phosphorus-containing macromolecular charring agent:

[0090] (3.1) Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanuric acid ester evenly and melt at 190 °C;

[0091] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanuric acid ester is 2:1:1;

[0092] (3.2) After adding the first catalyst to the system in step (3.1), stir and react for 4 h. During this process, continuously evacuate the air to remove the water generated by the reaction;

[0093] Among them, the mass addition amount of the first catalyst is 0.8% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, and 1,3,5-tris(2-hydroxyethyl)isocyanurate;

[0094] (3.3) After adding sodium bicarbonate to the system in step (3.2) (the mass addition amount of sodium bicarbonate is 3% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl)isocyanurate, and sodium bicarbonate), continue to stir and react for 1.5 h. After natural cooling, washing, and drying, a phosphorus-containing macromolecular charring agent is obtained.

[0095] The finally prepared phosphorus-containing macromolecular charring agent has the following structural formula:

[0096] ;

[0097] In the formula, the part between -C=O- and -COO- is composed of 2-7 segments, and each segment is independently selected from a segment of the esterification reaction product of 1,3,5-tris(2-hydroxyethyl)isocyanurate and the dicarboxyl DOPO derivative and a segment of the esterification reaction product of 1,3,5-tris(2-hydroxyethyl)isocyanurate and succinic acid; its infrared spectrum and proton nuclear magnetic resonance spectrum are respectively as Figure 5 , Figure 6 shown;

[0098] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 325 °C, the molecular weight is 10470, the phosphorus element content is 8320 ppm, the nitrogen element content is 4180 ppm, and the acid value is 7.7 mg KOH / g.

[0099] Example 2

[0100] A preparation method of a phosphorus-containing macromolecular charring agent, the specific steps are as follows:

[0101] (1) Raw material preparation:

[0102] DOPO;

[0103] Glyoxal;

[0104] Adipic acid;

[0105] Succinic acid;

[0106] 1,3,5-tris(2-hydroxyethyl)isocyanurate;

[0107] Sodium bicarbonate;

[0108] The first catalyst: p-toluenesulfonic acid;

[0109] The second catalyst: zinc acetate;

[0110] The solvent: absolute ethanol;

[0111] (2)Preparation of dicarboxyl DOPO derivative:

[0112] (2.1)Dissolve DOPO and glyoxal in the solvent, reflux at 90 °C for 3 h, then filter, wash and dry to obtain a white product;

[0113] Among them, the molar ratio of DOPO to glyoxal is 3:1;

[0114] (2.2)Mix the product obtained in step (2.1) with adipic acid evenly and melt at 190 °C;

[0115] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:10;

[0116] (2.3)Add the second catalyst to the system in step (2.2) (the mass addition amount of the second catalyst is 0.1% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 3.5 h, continuously introduce nitrogen during this process to remove the water generated by the reaction, and obtain the dicarboxyl DOPO derivative after washing and drying;

[0117] The prepared dicarboxyl DOPO derivative has the following structural formula:

[0118] ;

[0119] (3)Preparation of phosphorus-containing macromolecular charring agent:

[0120] (3.1)Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate evenly and melt at 160 °C;

[0121] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid to 1,3,5-tris(2-hydroxyethyl) isocyanurate is 1:1:1;

[0122] (3.2)Add the first catalyst to the system in step (3.1), stir and react for 2.5 h, continuously evacuate during this process to remove the water generated by the reaction;

[0123] Among them, the mass addition amount of the first catalyst is 0.5% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate;

[0124] (3.3) After adding sodium bicarbonate to the system of step (3.2) (the mass addition amount of sodium bicarbonate is 2% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl)isocyanuric acid ester and sodium bicarbonate), continue stirring and reacting for 1 h, and then obtain the phosphorus-containing macromolecular charring agent after natural cooling, washing and drying treatment.

[0125] The finally prepared phosphorus-containing macromolecular charring agent has the following structural formula:

[0126] ;

[0127] In the formula, the between -C=O- and -COO- is composed of 2-7 segments, and each segment is independently selected from one of the esterification reaction product segments of 1,3,5-tris(2-hydroxyethyl)isocyanuric acid ester and the dicarboxyl DOPO derivative and the esterification reaction product segments of 1,3,5-tris(2-hydroxyethyl)isocyanuric acid ester and succinic acid;

[0128] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 330 °C, the molecular weight is 12770, the phosphorus element content is 6510 ppm, the nitrogen element content is 3960 ppm, and the acid value is 6.1 mg KOH / g.

[0129] Example 3

[0130] A preparation method of a phosphorus-containing macromolecular charring agent, the specific steps are as follows:

[0131] (1) Raw material preparation:

[0132] DOPO;

[0133] Glyoxal;

[0134] Adipic acid;

[0135] Succinic acid;

[0136] 1,3,5-Tris(2-hydroxyethyl)isocyanuric acid ester;

[0137] Sodium bicarbonate;

[0138] First catalyst: phosphoric acid (mass fraction 85%);

[0139] Second catalyst: p-toluenesulfonic acid;

[0140] Solvent: acetonitrile;

[0141] (2) Preparation of dicarboxyl DOPO derivative:

[0142] (2.1) Dissolve DOPO and glyoxal in a solvent. After refluxing at 90 °C for 3 h, filter, wash and dry to obtain a white product;

[0143] Among them, the molar ratio of DOPO to glyoxal is 1.5:1;

[0144] (2.2) Uniformly mix the product obtained in step (2.1) with adipic acid and melt at 200 °C;

[0145] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:2;

[0146] (2.3) Add a second catalyst to the system in step (2.2) (the mass addition amount of the second catalyst is 0.5% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 4.5 h. During this process, continuously introduce nitrogen to remove the water generated by the reaction. After washing and drying, the dicarboxyl DOPO derivative is obtained;

[0147] The prepared dicarboxyl DOPO derivative has the following structural formula:

[0148] ;

[0149] (3) Prepare a phosphorus-containing macromolecular charring agent:

[0150] (3.1) Uniformly mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate and melt at 200 °C;

[0151] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid to 1,3,5-tris(2-hydroxyethyl) isocyanurate is 5:1:2;

[0152] (3.2) Add a first catalyst to the system in step (3.1), stir and react for 4 h. During this process, continuously evacuate to remove the water generated by the reaction;

[0153] Among them, the mass addition amount of the first catalyst is 1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate;

[0154] (3.3) Add sodium bicarbonate to the system in step (3.2) (the mass addition amount of sodium bicarbonate is 5% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl) isocyanurate and sodium bicarbonate), continue to stir and react for 2 h. After natural cooling, washing and drying, the phosphorus-containing macromolecular charring agent is obtained.

[0155] The finally prepared phosphorus-containing macromolecular charring agent has the following structural formula:

[0156] ;

[0157] In the formula, the is composed of 2-7 segments, and each segment is independently selected from the esterification reaction product segment of 1,3,5-tris(2-hydroxyethyl)isocyanurate and dicarboxyl DOPO derivative and the esterification reaction product segment of 1,3,5-tris(2-hydroxyethyl)isocyanurate and succinic acid;

[0158] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 310 °C, the molecular weight is 8000, the phosphorus element content is 9970 ppm, the nitrogen element content is 3020 ppm, and the acid value is 9.9 mg KOH / g.

[0159] Example 4

[0160] A preparation method of a phosphorus-containing macromolecular charring agent, the specific steps are as follows:

[0161] (1) Raw material preparation:

[0162] DOPO;

[0163] Glyoxal;

[0164] Adipic acid;

[0165] Succinic acid;

[0166] 1,3,5-tris(2-hydroxyethyl)isocyanurate;

[0167] Sodium bicarbonate;

[0168] The first catalyst: p-toluenesulfonic acid;

[0169] The second catalyst: p-toluenesulfonic acid;

[0170] The solvent: acetone;

[0171] (2) Preparation of dicarboxyl DOPO derivative:

[0172] (2.1) Dissolve DOPO and glyoxal in the solvent, reflux at 90 °C for 3 h, then filter, wash and dry to obtain a white product;

[0173] Among them, the molar ratio of DOPO to glyoxal is 10:1;

[0174] (2.2) Uniformly mix the product obtained in step (2.1) with adipic acid and melt at 210 °C;

[0175] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:5;

[0176] (2.3) After adding a second catalyst to the system in step (2.2) (the mass addition amount of the second catalyst is 0.1% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 5 h. During this process, nitrogen is continuously introduced to remove the water generated by the reaction. After washing and drying, the dicarboxyl DOPO derivative is obtained;

[0177] The obtained dicarboxyl DOPO derivative has the following structural formula:

[0178] ;

[0179] (3) Preparation of a phosphorus-containing macromolecular charring agent:

[0180] (3.1) Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate evenly and melt at 170 °C;

[0181] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate is 5:1:5;

[0182] (3.2) After adding a first catalyst to the system in step (3.1), stir and react for 2 h. During this process, vacuum is continuously pumped to remove the water generated by the reaction;

[0183] Among them, the mass addition amount of the first catalyst is 0.1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate;

[0184] (3.3) After adding sodium bicarbonate to the system in step (3.2) (the mass addition amount of sodium bicarbonate is 1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl) isocyanurate and sodium bicarbonate), continue to stir and react for 0.5 h. After natural cooling, washing and drying, the phosphorus-containing macromolecular charring agent is obtained.

[0185] The finally obtained phosphorus-containing macromolecular charring agent has the following structural formula:

[0186] ;

[0187] In the formula, the between -C=O- and -COO- is composed of 2-7 segments, and each segment is independently selected from a segment of the esterification reaction product of 1,3,5-tris(2-hydroxyethyl) isocyanurate and the dicarboxyl DOPO derivative and a segment of the esterification reaction product of 1,3,5-tris(2-hydroxyethyl) isocyanurate and succinic acid;

[0188] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 332 °C, the molecular weight is 15320, the phosphorus element content is 7790 ppm, the nitrogen element content is 4300 ppm, and the acid value is 5.4 mg KOH / g.

[0189] Example 5

[0190] A preparation method of a phosphorus-containing macromolecular charring agent, the specific steps are as follows:

[0191] (1) Raw material preparation:

[0192] DOPO;

[0193] Glyoxal;

[0194] Adipic acid;

[0195] Succinic acid;

[0196] 1,3,5-Tris(2-hydroxyethyl)isocyanuric acid ester;

[0197] Sodium bicarbonate;

[0198] The first catalyst: p-toluenesulfonic acid;

[0199] The second catalyst: Zinc acetate;

[0200] Solvent: Dimethyl sulfoxide;

[0201] (2) Preparation of dicarboxyl DOPO derivative:

[0202] (2.1) Dissolve DOPO and glyoxal in the solvent, reflux at 110 °C for 3 h, then filter, wash and dry to obtain a white product;

[0203] Among them, the molar ratio of DOPO to glyoxal is 1.5:1;

[0204] (2.2) Uniformly mix the product obtained in step (2.1) with adipic acid and melt at 220 °C;

[0205] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:6;

[0206] (2.3) Add the second catalyst to the system in step (2.2) (the mass addition amount of the second catalyst is 0.3% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 3.2 h, continuously pass nitrogen during this process to remove the water generated by the reaction, and obtain the dicarboxyl DOPO derivative after washing and drying;

[0207] The prepared dicarboxyl DOPO derivative, its structural formula is:

[0208] ;

[0209] (3) Preparation of phosphorus-containing macromolecular charring agent:

[0210] (3.1) Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate evenly and melt at 190 °C;

[0211] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate is 3:1:4;

[0212] (3.2) After adding the first catalyst to the system in step (3.1), stir and react for 2 h, and continuously evacuate during this process to remove the water generated by the reaction;

[0213] Among them, the mass addition amount of the first catalyst is 0.2% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl) isocyanurate;

[0214] (3.3) After adding sodium bicarbonate to the system in step (3.2) (the mass addition amount of sodium bicarbonate is 0.1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl) isocyanurate and sodium bicarbonate), continue to stir and react for 0.5 h, and obtain the phosphorus-containing macromolecular charring agent after natural cooling, washing and drying.

[0215] The finally prepared phosphorus-containing macromolecular charring agent has the following structural formula:

[0216] ;

[0217] In the formula, the between -C=O- and -COO- is composed of 2-7 chain segments, and each chain segment is independently selected from one of the esterification reaction product chain segments of 1,3,5-tris(2-hydroxyethyl) isocyanurate and the dicarboxyl DOPO derivative and the esterification reaction product chain segment of 1,3,5-tris(2-hydroxyethyl) isocyanurate and succinic acid;

[0218] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 350 °C, the molecular weight is 19,860, the phosphorus element content is 5630 ppm, the nitrogen element content is 4980 ppm, and the acid value is 4.1 mg KOH / g.

[0219] Example 6

[0220] A preparation method of a phosphorus-containing macromolecular charring agent, and the specific steps are as follows:

[0221] (1) Raw material preparation:

[0222] DOPO;

[0223] Glyoxal;

[0224] Adipic acid;

[0225] Succinic acid;

[0226] 1,3,5-Tris(2-hydroxyethyl)isocyanuric acid;

[0227] Sodium bicarbonate;

[0228] The first catalyst: Phosphoric acid (mass fraction is 85%);

[0229] The second catalyst: p-Toluenesulfonic acid;

[0230] Solvent: N,N-Dimethylformamide;

[0231] (2) Preparation of dicarboxyl DOPO derivative:

[0232] (2.1) Dissolve DOPO and glyoxal in the solvent, reflux at 110 °C for 3 h, then filter, wash and dry to obtain a white product;

[0233] Among them, the molar ratio of DOPO to glyoxal is 4:1;

[0234] (2.2) Mix the product obtained in step (2.1) with adipic acid evenly and melt at 190 °C;

[0235] Among them, the molar ratio of the product obtained in step (2.1) to adipic acid is 1:3;

[0236] (2.3) Add the second catalyst to the system in step (2.2) (the mass addition amount of the second catalyst is 0.2% of the total mass addition amount of DOPO, glyoxal and adipic acid), stir and react for 4 h. During this process, continuously introduce nitrogen to remove the water generated by the reaction. After washing and drying, the dicarboxyl DOPO derivative is obtained;

[0237] The prepared dicarboxyl DOPO derivative has the following structural formula:

[0238] ;

[0239] (3) Preparation of phosphorus-containing macromolecular charring agent:

[0240] (3.1) Mix the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanuric acid evenly and melt at 180 °C;

[0241] Among them, the molar ratio of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanuric acid is 2:1:3;

[0242] (3.2) After adding the first catalyst to the system in step (3.1), stir and react for 2.2 h. During this process, continuously evacuate the air to remove the water generated by the reaction;

[0243] Among them, the mass addition amount of the first catalyst is 0.3% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, and 1,3,5-tris(2-hydroxyethyl)isocyanurate;

[0244] (3.3) After adding sodium bicarbonate to the system in step (3.2) (the mass addition amount of sodium bicarbonate is 0.4% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl)isocyanurate, and sodium bicarbonate), continue to stir and react for 1 h. After natural cooling, washing, and drying, the phosphorus-containing macromolecular charring agent is obtained.

[0245] The finally prepared phosphorus-containing macromolecular charring agent has the following structural formula:

[0246] ;

[0247] In the formula, the between -C=O- and -COO- is composed of 2-7 segments, and each segment is independently selected from one of the esterification reaction product segments of 1,3,5-tris(2-hydroxyethyl)isocyanurate and the dicarboxyl DOPO derivative and the esterification reaction product segments of 1,3,5-tris(2-hydroxyethyl)isocyanurate and succinic acid;

[0248] The 5% thermal weight loss temperature of the phosphorus-containing macromolecular charring agent is 348 °C, the molecular weight is 19,570, the phosphorus element content is 5250 ppm, the nitrogen element content is 4870 ppm, and the acid value is 4.2 mg KOH / g.

[0249] Example 7

[0250] A flame-retardant polyester composite material, and the specific steps are as follows:

[0251] (1) Raw material preparation:

[0252] Polyester resin: polyethylene terephthalate;

[0253] Glass fiber: alkali-free glass fiber, with an average length of 2.3 mm;

[0254] Aluminum phosphite: produced by Hunan Meilaipo Technology Development Co., Ltd. / Shanghai Lidao New Material Technology Co., Ltd., with the product number M119-S and without crystal water;

[0255] Phosphorus-containing macromolecular charring agent: prepared in Example 1;

[0256] (2) Preparation of flame-retardant glass fiber-reinforced polyester resin composition:

[0257] Weigh 77.5 parts of polyester resin, 15 parts of glass fiber, 2.5 parts of aluminum phosphite, and 5 parts of phosphorus-containing macromolecular charring agent by weight;

[0258] Mix them evenly to obtain the flame-retardant glass fiber-reinforced polyester resin composition;

[0259] (3) Preparation of flame-retardant polyester composite:

[0260] The flame-retardant glass fiber-reinforced polyester resin composition is melt-blended at 280 °C and then cooled, dried, pelletized, and injection-molded in sequence.

[0261] The finally prepared flame-retardant polyester composite produces non-flaming melt droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 30.5%, a tensile strength of 110 MPa, a flexural strength of 162 MPa, and a notched Izod impact strength of 7.5 KJ / m 2 .

[0262] Example 8

[0263] A flame-retardant polyester composite, the specific steps are as follows:

[0264] (1) Raw material preparation:

[0265] Polyester resin: Polybutylene terephthalate;

[0266] Glass fiber: E-glass fiber, with an average length of 3.8 mm;

[0267] Aluminum phosphite: Produced by Hunan Meilaiper Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., with the product number M119-S and no crystal water;

[0268] Phosphorus-containing macromolecular charring agent: Prepared in Example 2;

[0269] (2) Preparation of flame-retardant glass fiber-reinforced polyester resin composition:

[0270] Weigh 70 parts of polyester resin, 16 parts of glass fiber, 4 parts of aluminum phosphite, and 10 parts of phosphorus-containing macromolecular charring agent by weight;

[0271] Mix them evenly to obtain the flame-retardant glass fiber-reinforced polyester resin composition;

[0272] (3) Preparation of flame-retardant polyester composite:

[0273] The flame-retardant glass fiber-reinforced polyester resin composition is melt-blended at 230 °C and then cooled, dried, pelletized, and injection-molded in sequence.

[0274] The flame-retardant polyester composite material finally produced produces flameless droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 35.5%, a tensile strength of 100MPa, a flexural strength of 150MPa, and a simply supported beam notched impact strength of 7KJ / m 2 .

[0275] Example 9

[0276] A flame retardant polyester composite material, comprising the following specific steps:

[0277] (1) Raw material preparation:

[0278] Polyester resin: a mixture of polyethylene terephthalate and polybutylene terephthalate in a mass ratio of 1:1;

[0279] Glass fiber: Alkali-free glass fiber, average length is 1.7mm;

[0280] Aluminum phosphite: produced by Hunan Meilaipo Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., brand M119-S, no crystal water;

[0281] Phosphorus-containing macromolecular carbon-forming agent: prepared in Example 3;

[0282] (2) Preparation of flame-retardant glass fiber reinforced polyester resin composition:

[0283] According to weight, 61 parts of polyester resin, 30 parts of glass fiber, 3 parts of aluminum phosphite, and 6 parts of phosphorus-containing macromolecular carbon-forming agent were weighed;

[0284] The flame retardant glass fiber reinforced polyester resin composition is obtained by uniformly mixing;

[0285] (3) Preparation of flame-retardant polyester composite materials:

[0286] The flame retardant glass fiber reinforced polyester resin composition is melt-blended at 260° C. and then cooled, dried, pelletized and injection-molded in sequence.

[0287] The flame-retardant polyester composite material finally produced produces flameless droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 33.5%, a tensile strength of 150 MPa, a flexural strength of 180 MPa, and a simply supported beam notched impact strength of 9 KJ / m 2 .

[0288] Example 10

[0289] A flame retardant polyester composite material, comprising the following specific steps:

[0290] (1) Raw material preparation:

[0291] Polyester resin: A mixture of polyethylene terephthalate and polybutylene terephthalate with a mass ratio of 4:1;

[0292] Glass fiber: E-glass fiber with an average length of 1.5 mm;

[0293] Aluminum phosphite: Produced by Hunan Meilaipo Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., with the brand M119-S and no crystal water;

[0294] Phosphorus-containing macromolecular charring agent: Prepared in Example 4;

[0295] (2) Preparation of flame-retardant glass fiber-reinforced polyester resin composition:

[0296] Weigh 70 parts by weight of polyester resin, 21.5 parts of glass fiber, 3.5 parts of aluminum phosphite, and 5 parts of phosphorus-containing macromolecular charring agent;

[0297] Mix evenly to obtain the flame-retardant glass fiber-reinforced polyester resin composition;

[0298] (3) Preparation of flame-retardant polyester composite:

[0299] The flame-retardant glass fiber-reinforced polyester resin composition is melt-blended at 270 °C and then cooled, dried, pelletized, and injection-molded in sequence.

[0300] The finally prepared flame-retardant polyester composite produces non-flaming molten droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 32%, a tensile strength of 129 MPa, a flexural strength of 168 MPa, and a notched Izod impact strength of 7.8 KJ / m 2 .

[0301] Example 11

[0302] A flame-retardant polyester composite, the specific steps are as follows:

[0303] (1) Raw material preparation:

[0304] Polyester resin: A mixture of polyethylene terephthalate and polybutylene terephthalate with a mass ratio of 1:1.5;

[0305] Glass fiber: E-glass fiber with an average length of 5 mm;

[0306] Aluminum phosphite: Produced by Hunan Meilaipo Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., with the brand M119-S and no crystal water;

[0307] Phosphorus-containing macromolecular charring agent: Prepared in Example 5;

[0308] (2) Preparation of flame-retardant glass fiber-reinforced polyester resin composition:

[0309] Weigh 75 parts by weight of polyester resin, 15.5 parts of glass fiber, 2.5 parts of aluminum phosphite, and 7 parts of phosphorus-containing macromolecular charring agent;

[0310] Mix them evenly to obtain the flame-retardant glass fiber-reinforced polyester resin composition;

[0311] (3) Preparation of flame-retardant polyester composite material:

[0312] The flame-retardant glass fiber-reinforced polyester resin composition is melt-blended at 260 °C and then cooled, dried, pelletized, and injection-molded in sequence.

[0313] The finally obtained flame-retardant polyester composite material produces non-flaming melt droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 34.5%, a tensile strength of 108 MPa, a flexural strength of 159 MPa, and a notched Izod impact strength of 7.4 KJ / m 2 .

[0314] Comparative Example 1

[0315] A polyester composite material, which is basically the same as Example 11, except that: in this comparative example, the charring agent TMA prepared by reacting DOPO, maleic anhydride (MA), and 1,3,5-tris(2-hydroxyethyl) isocyanurate (from the literature: A novel phosphorus / nitrogen-containing polycarboxylic acid endowing epoxy resin with excellent flame retardance and mechanical properties[J]. Chemical Engineering Journal, 2019, 375: 121916.) is used to replace the phosphorus-containing macromolecular charring agent in Example 11.

[0316] The finally obtained polyester composite material produces flaming melt droplets during combustion, ignites absorbent cotton, does not meet the UL-94 V-0 test standard, has a limiting oxygen index of 30%, a tensile strength of 81 MPa, a flexural strength of 127 MPa, and a notched Izod impact strength of 6.5 KJ / m 2 .

[0317] Comparative Example 2

[0318] A polyester composite material is basically the same as that in Example 11, except that: in this comparative example, a charring agent IPDI-DOPO-HQ-THEIC prepared by reacting DOPO-DQ, isophorone diisocyanate (IPDI), and 1,3,5-tris(2-hydroxyethyl)isocyanurate (from the literature: Preparation and Research of Phosphorus-containing Flame Retardant Epoxy Resins [D]. Shanghai Institute of Technology, 2020.) is used to replace the phosphorus-containing macromolecular charring agent in Example 11.

[0319] During the combustion process of the finally prepared polyester composite material, flaming droplets are generated, which ignite absorbent cotton, and it does not meet the UL-94 V-0 test standard. The limiting oxygen index is 28.5%, the tensile strength is 93 MPa, the flexural strength is 131 MPa, and the notched impact strength of the simply supported beam is 7.3 KJ / m 2 .

[0320] From the results of Example 11, Comparative Example 1, and Comparative Example 2, it can be seen that compared with Example 11, the polyester composite materials prepared in Comparative Example 1 and Comparative Example 2 show worse performance in terms of flame retardancy and mechanical properties. The reasons are as follows: the charring agents prepared in the comparative examples have a lower molecular weight and contain a large number of terminal carboxyl groups, and these structures are prone to promoting the thermal degradation of the polyester during processing, thereby reducing its mechanical strength; at the same time, the charring agents in the comparative examples do not introduce a sodium salt structure, and sodium salts can promote the formation of fine droplets during the combustion of the polyester resin; due to the lack of this structure, the droplet-promoting performance of the charring agents in the comparative examples is limited; in addition, the lower molecular weight also leads to the difficulty of the charring agent to form a dense carbon layer attached to the surface of the glass fiber, unable to effectively overcome the wick effect of the glass fiber, and thus resulting in a decline in flame retardancy.

[0321] Comparative Example 3

[0322] A polyester composite material is basically the same as that in Example 11, except that: in this comparative example, a phosphorus-containing macromolecular charring agent without sodium salt is used to replace the phosphorus-containing macromolecular charring agent in Example 11;

[0323] The preparation process of the phosphorus-containing macromolecular charring agent without sodium salt is basically the same as that in Example 5, except that: step (3.3) is omitted.

[0324] During the combustion process of the finally prepared polyester composite material, flaming droplets are generated, which ignite absorbent cotton, and it does not meet the UL-94 V-0 test standard. The limiting oxygen index is 31%, the tensile strength is 98 MPa, the flexural strength is 132 MPa, and the notched impact strength of the simply supported beam is 7.2 KJ / m 2 .

[0325] Compared with Example 11, the polyester composite prepared in Comparative Example 3 shows worse performance in both flame retardancy and mechanical properties. The reason is that the charring agent in the comparative example does not introduce a sodium salt structure, and the sodium salt can promote the formation of fine droplets during the combustion of the polyester resin. Due to the lack of this structure, the droplet-promoting performance of the charring agent in the comparative example is limited.

[0326] Example 12

[0327] A flame-retardant polyester composite, the specific steps are as follows:

[0328] (1) Raw material preparation:

[0329] Polyester resin: A mixture of polyethylene terephthalate and polybutylene terephthalate with a mass ratio of 1:7;

[0330] Glass fiber: Alkali-free glass fiber with an average length of 4.3 mm;

[0331] Aluminum phosphite: Produced by Hunan Meilaiper Technology Development Co., Ltd. / Shanghai Lidao New Materials Technology Co., Ltd., with the brand M119-S and no crystal water;

[0332] Phosphorus-containing macromolecular charring agent: Prepared in Example 6;

[0333] (2) Preparation of flame-retardant glass fiber-reinforced polyester resin composition:

[0334] Weigh 65 parts by weight of polyester resin, 22.5 parts of glass fiber, 3.5 parts of aluminum phosphite, and 9 parts of phosphorus-containing macromolecular charring agent;

[0335] Mix evenly to obtain the flame-retardant glass fiber-reinforced polyester resin composition;

[0336] (3) Preparation of flame-retardant polyester composite:

[0337] The flame-retardant glass fiber-reinforced polyester resin composition is melt-blended at 240 °C and then cooled, dried, pelletized, and injection-molded in sequence.

[0338] The finally prepared flame-retardant polyester composite produces non-flaming droplets during combustion, does not ignite absorbent cotton, meets the UL-94 V-0 test standard, has a limiting oxygen index of 35%, a tensile strength of 138 MPa, a flexural strength of 172 MPa, and a notched Izod impact strength of 8.2 KJ / m 2 .

[0339] Comparative Example 4

[0340] A polyester composite, which is basically the same as Example 12, except that in this comparative example, the aluminum polyphosphite (containing crystal water) of Shenzhen Ruishixing Technology Co., Ltd. is used to replace the aluminum phosphite in Example 12.

[0341] The finally obtained polyester composite material generates flaming droplets during the combustion process, igniting absorbent cotton, not meeting the UL-94 V-0 test standard, and the limiting oxygen index is 30%.

[0342] Compared with Example 12, the flame retardancy of the polyester composite material prepared in Comparative Example 4 becomes worse. The reason is that this aluminum phosphite contains 2% crystal water. During the combustion process, a large amount of water vapor will be generated by the crystal water, destroying the compactness of the carbon layer and enabling the continuous exchange of combustion elements (oxygen, combustibles, heat) inside and outside the combustion environment, thus leading to a decrease in flame retardancy.

Claims

1. A phosphorus-containing macromolecular carbon-forming agent, characterized in that: The structural formula is as follows: ； The structural formula of the dicarboxyl DOPO derivative is as follows: ； The preparation method of the phosphorus-containing macromolecular carbon-forming agent comprises the following steps: (a) mixing a dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate in a molar ratio of 1-5:1:1-5 and melting the mixture at 150-220° C.; (b) adding the first catalyst to the system of step (a), stirring and reacting for 2-4 hours, during which time vacuum is continuously drawn to remove water produced by the reaction; (c) After adding sodium bicarbonate to the system of step (b), the reaction is continued with stirring for 0.5-2 hours, and a phosphorus-containing macromolecular carbon-forming agent is obtained after post-treatment; the mass amount of sodium bicarbonate added is 0.1-5% of the total mass amount of the dicarboxy DOPO derivative, succinic acid, 1,3,5-tris(2-hydroxyethyl)isocyanurate and sodium bicarbonate added.

2. A phosphorus-containing macromolecular carbon-forming agent according to claim 1, characterized in that: The 5% thermal weight loss temperature of the phosphorus-containing macromolecular carbonizing agent is ≥300°C, the molecular weight is 8000-20000, the phosphorus content is 5000-10000ppm, the nitrogen content is 3000-5000ppm, and the acid value is 4.1-9.9mg KOH / g.

3. A phosphorus-containing macromolecular carbon-forming agent according to claim 2, characterized in that: In step (a), the preparation steps of the dicarboxyl DOPO derivative are as follows: (i) dissolving DOPO and glyoxal in a solvent, reflux at 90-110° C. for 3 h, filtering, washing and drying to obtain a product; (ii) uniformly mixing the product obtained in step (i) with adipic acid and melting the mixture at 180-220° C.; (iii) After adding the second catalyst to the system of step (ii), stirring the reaction for 3-5 hours, during which nitrogen is continuously passed to remove the water produced by the reaction, and the dicarboxyl DOPO derivative is obtained after post-treatment.

4. A phosphorus-containing macromolecular carbon-forming agent according to claim 3, characterized in that: In the preparation process of the dicarboxyl DOPO derivative, the molar ratio of DOPO to glyoxal is 1.5-10:1; the molar ratio of the product obtained in step (i) to adipic acid is 1:1.5-10; the second catalyst is p-toluenesulfonic acid or zinc acetate, and the mass addition amount of the second catalyst is 0.1-1% of the total mass addition amount of DOPO, glyoxal and adipic acid.

5. A phosphorus-containing macromolecular carbon-forming agent according to claim 3, characterized in that: In the preparation process of the phosphorus-containing macromolecular carbon-forming agent, the first catalyst is concentrated sulfuric acid, p-toluenesulfonic acid or phosphoric acid, and the mass addition amount of the first catalyst is 0.1-1% of the total mass addition amount of the dicarboxyl DOPO derivative, succinic acid and 1,3,5-tris(2-hydroxyethyl)isocyanurate.

6. A flame retardant glass fiber reinforced polyester resin composition using a phosphorus-containing macromolecular carbon-forming agent as claimed in any one of claims 1 to 5, characterized in that: The invention is composed of 60-80 parts of polyester resin, 15-30 parts of glass fiber, 2.5-4 parts of aluminum phosphite and 5-10 parts of phosphorus-containing macromolecular carbon-forming agent by weight, and the aluminum phosphite contains no crystal water.

7. The flame retardant glass fiber reinforced polyester resin composition according to claim 6, characterized in that: The polyester resin is one or more of polyethylene terephthalate and polybutylene terephthalate; the glass fiber is alkali-free glass fiber with a length of 1.5-5.0 mm.

8. A flame retardant polyester composite material, characterized in that: The flame retardant glass fiber reinforced polyester resin composition according to claim 6 or 7 is prepared by melt blending and then cooling, drying, pelletizing and injection molding in sequence, wherein the melt blending temperature is 230-280°C.

9. The flame retardant polyester composite material according to claim 8, characterized in that: Flame-retardant polyester composite materials produce flameless droplets during combustion, do not ignite absorbent cotton, meet UL-94 V-0 test standards, limit oxygen index ≥ 30.5%, tensile strength of 100-150MPa, flexural strength of 150-180MPa, simple beam notched impact strength of 7-9KJ / m 2 .

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