Polyvinyl chloride and flame-retardant smoke suppressant thereof

Abstract

The invention discloses polyvinyl chloride and a flame-retardant smoke suppressant thereof, and aims to solve the problem of low flame-retardant smoke suppression efficiency of a traditional flame-retardant smoke suppressant. The polyvinyl chloride comprises the following components: PVC resin, a plasticizer, a flame-retardant smoke suppressant, a heat stabilizer and a lubricant, and the flame-retardant smoke suppressant comprises a phenylboronic acid ester polymer and a phosphorus flame retardant. The flame-retardant and smoke-suppressing agent is a composition of a high-molecular borate polymer and a phosphorus flame retardant, during combustion, the phosphorus flame retardant is decomposed at high temperature to absorb heat, and meanwhile, the borate polymer generates a compact carbon layer during combustion, so that smoke is blocked, the flame-retardant and smoke-suppressing effects are achieved, and the flame-retardant and smoke-suppressing effects are achieved. Meanwhile, the metal ions promote the carbon layer to form a cross-linked structure, and the carbon forming amount is further increased to improve the flame-retardant and smoke-suppression effects.

Description

Technical Field

[0001] The present invention relates to the technical field of synthesis and application of flame retardants, in particular to polyvinyl chloride and a flame retardant and smoke suppressant thereof. Background Art

[0002] Polyvinyl chloride (PVC) is a key plastic product widely used in conveyor belts, building materials, wire and cable, and artificial leather. While PVC inherently possesses certain flame retardancy (with a limiting oxygen index (LOI) of approximately 45%), plasticizers are often added to its composite materials in practical applications, making them flammable and releasing large amounts of toxic and hazardous smoke (primarily hydrogen chloride, benzene, and toluene). Consequently, the flame retardancy and smoke suppression of PVC materials have become a hot topic of research in the PVC field. Currently, commonly used flame retardants and smoke suppressants are classified into the following categories: ① halogen-based flame retardants; ② phosphorus-nitrogen-based flame retardants; ③ nitrogen-based flame retardants; ④ double hydroxides (aluminum hydroxide and magnesium hydroxide); ⑤ microencapsulated red phosphorus; and ⑥ metal oxides. These flame retardants and smoke suppressants generally suffer from low flame retardancy and smoke suppression efficiency. Therefore, the exploration of novel processing methods to prepare novel flame retardants and smoke suppressants that effectively enhance the flame retardancy of PVC while reducing smoke emissions has attracted considerable research attention. Summary of the Invention

[0003] The purpose of the present invention is to provide a polyvinyl chloride and a flame retardant and smoke suppressant thereof to solve the problem of low flame retardant and smoke suppressant efficiency of traditional flame retardants and smoke suppressants. The flame retardant and smoke suppressant in the present invention is a composition of a phenyl borate polymer and a phosphorus-based flame retardant. During combustion, the phosphorus-based flame retardant decomposes at high temperature to absorb heat. At the same time, the borate polymer generates a dense carbon layer to block smoke, thereby achieving the flame retardant and smoke suppression effect.

[0004] To achieve the above object, the present invention provides the following technical solution: a flame retardant and smoke suppressant, comprising the following components in parts by weight: 1 to 6 parts of a borate polymer and 10 to 15 parts of a phosphorus flame retardant. Furthermore, in the flame retardant and smoke suppressant, the composition includes 3 parts by weight of borate polymer and 10 parts by weight of aluminum hypophosphite.

[0005] Furthermore, in the above flame retardant and smoke suppressant, the preparation method of the borate ester polymer comprises the following steps: S1. Dissolve a phenylboronic acid ester monomer and an initiator in an organic solvent, then transfer the mixture to a flask and stir at room temperature until transparent to obtain a solution A, wherein the mass ratio of the benzoic acid ester monomer to the initiator is 10-20:1, and the volume of the organic solvent is 20-80 mL / g based on the mass of the phenylboronic acid monomer; S2. Add a polyhydroxy compound dropwise to solution A at a rate of 0.56-3.3 mL / min, heat to reflux temperature under stirring, and react for 24 hours. The resulting reaction solution B is filtered and washed with toluene to obtain a borate polymer, wherein the mass ratio of the polyhydroxy compound to the phenyl borate monomer is 1:1-3, the stirring speed is 200-2000 rpm, and the reflux temperature is 90-180°C.

[0006] Furthermore, in the flame retardant and smoke suppressant, the phenyl borate monomer is one or more of phenylboronic acid, 3-aminophenylboronic acid, and p-methylphenylboronic acid.

[0007] Furthermore, in the above-mentioned flame retardant and smoke suppressant, the initiator is one or more of lithium chloride, azobisisobutyronitrile, and ditoluoyl peroxide.

[0008] Furthermore, in the above-mentioned flame retardant and smoke suppressant, the organic solvent is one or more of toluene, dichloromethane, and chloroform.

[0009] Furthermore, in the above-mentioned flame retardant and smoke suppressant, the polyhydroxy compound is one or more of diethanolamine, ethylene glycol, and glycerol.

[0010] The present invention also provides a polyvinyl chloride, comprising the following principle components in parts by weight: 100 parts of PVC resin, 40 parts of plasticizer, 10-20 parts of flame retardant and smoke suppressant, 3-6 parts of heat stabilizer, and 0.3-0.6 parts of lubricant, wherein the flame retardant and smoke suppressant is the above-mentioned flame retardant and smoke suppressant.

[0011] Furthermore, in the above polyvinyl chloride, the heat stabilizer is one of dibasic lead phosphite and barium stearate, or a mixture of the two.

[0012] Furthermore, in the above polyvinyl chloride, the lubricant is one or a mixture of paraffin and stearic acid.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The flame retardant and smoke suppressant in the present invention is a composition of a high molecular weight borate polymer and a phosphorus flame retardant. During combustion, the phosphorus flame retardant decomposes at high temperature to absorb heat. At the same time, the borate polymer generates a dense carbon layer during combustion, thereby blocking the smoke to achieve the flame retardant and smoke suppression effect. At the same time, metal ions promote the formation of a cross-linked structure in the carbon layer, further increasing the amount of carbon formed to enhance the flame retardant and smoke suppression effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A synthetic route for borate ester polymers; Figure 2 This is a structural representation diagram of the flame retardant and smoke suppressant of the present invention; Figure 3 This is a test result diagram of the PVC sample in the present invention. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0016] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in the industry, as shown in Table 1. The methods in the following embodiments, unless otherwise specified, are all conventional methods in the art.

[0017] Table 1 Experimental raw materials

[0018] Example 1 (1) Weigh 3 g of phenylboric acid (PBA), 150 mL of toluene (MB) and 203.47 mg of lithium chloride into a three-necked flask with magnetic stirring and stir for 30 min to obtain a transparent solution A. Then, 2.58 g of diethanolamine (DEA) was added to the solution A at a rate of 0.83 mL / min. The mixture was stirred at 1000 rpm at 120 °C and refluxed for 24 h. After filtration and multiple washing with toluene, the product polyphenyl borate was obtained. The reaction process is described in [1]. Figure 1 As shown; (2) The structure of the product was verified by FTIR. Figure 2 Middle, 3300~3500 cm -1 The newly appeared peak corresponds to the stretching vibration of NH in diethanolamine. However, the absorption peak of -OH in the monomer structure of phenylboronic acid also appears in this range. At the same time, due to the association between hydroxyl groups, a broad and large peak is formed, which is difficult to distinguish accurately. -1 、1370 cm -1 The characteristic absorption peaks of the aromatic ring skeleton and BOC are 2860~2930 cm -1 The stretching vibration absorption peak of -CH2- is located at the bottom of the reaction. The appearance of characteristic peaks such as -CH2- and BOC in the final product structure indicates that phenylboronic acid and diethanolamine have successfully reacted. (3) According to the formula, 100 parts of PVC resin, 40 parts of plasticizer, 3 parts of polyphenyl borate, 10 parts of aluminum hypophosphite, 6 parts of barium stearate, and 0.5 parts of stearic acid were mixed by high-speed stirring, placed in a two-roll mill and mixed at 160°C for 6 minutes, then the sheet was taken out and cooled, and then molded into a specimen of the required thickness at 180°C for use in the vertical burning test (UL-94) and the total smoke release (TSP) test.

[0019] Example 2 The difference between Example 2 and Example 1 is that the amount of polyphenyl borate is reduced from 3 parts to 1 part.

[0020] According to the formula, 100 parts of PVC resin, 40 parts of plasticizer, 1 part of polyphenyl borate, 10 parts of aluminum hypophosphite, 6 parts of barium stearate, and 0.5 parts of stearic acid are mixed with high-speed stirring, placed in a two-roll mill and mixed at 160°C for 6 minutes, then the pulled sheet is taken out and cooled, and then molded into specimens of the required thickness at 180°C for use in vertical burning tests (UL-94) and total smoke release (TSP) tests.

[0021] Example 3 The difference between Example 3 and Example 1 is that the amount of polyphenyl borate is increased from 3 parts to 5 parts.

[0022] According to the formula, 100 parts of PVC resin, 40 parts of plasticizer, 5 parts of polyphenyl borate, 10 parts of aluminum hypophosphite, 6 parts of barium stearate, and 0.5 parts of stearic acid are mixed with high-speed stirring, placed in a two-roll mill and mixed at 160°C for 6 minutes, then the pulled sheet is taken out and cooled, and then molded into specimens of the required thickness at 180°C for use in vertical burning tests (UL-94) and total smoke release (TSP) tests.

[0023] Comparative Example 1 According to the formula, 100 parts of PVC resin, 40 parts of plasticizer, 13 parts of polyphenyl borate, 6 parts of barium stearate, and 0.5 parts of stearic acid are mixed with high-speed stirring, placed in a two-roll mill and mixed at 160°C for 6 minutes, then the pulled sheet is taken out and cooled, and then molded into specimens of the required thickness at 180°C for use in vertical burning tests (UL-94) and total smoke release (TSP) tests.

[0024] Comparative Example 2 According to the formula, 100 parts of PVC resin, 40 parts of plasticizer, 13 parts of aluminum hypophosphite, 6 parts of barium stearate, and 0.5 parts of stearic acid are mixed with high-speed stirring, placed in a two-roll mill and mixed at 160°C for 6 minutes, then the pulled sheet is taken out and cooled, and then molded into specimens of the required thickness at 180°C for use in vertical burning tests (UL-94) and total smoke release (TSP) tests.

[0025] Performance Testing The preparation method of the vertical combustion test and the total smoke release test strip of the PVC sample in the present invention is as follows: Vertical combustion specimens: Tested in accordance with ASTM D3801-10, specimens with a size of 130 × 13 × 3 mm3 were prepared by hot pressing.

[0026] Total smoke release specimens: According to ISO 5660-1, the fire combustion performance of PVC specimens was analyzed using a cone calorimeter. The sample size was 100×100×3 mm3 and the radiation flux was 35 kW / m2.

[0027] The PVC samples obtained in Examples 1 to 3 and Comparative Examples 1 to 2 were subjected to vertical combustion test and cone calorimetry test. The results are shown in Table 2. Figure 3 .

[0028] Table 2 Test results of Examples 1-3 and Comparative Examples 1-2

[0029] From Table 2 and Figure 3 The results show that for PVC samples, when aluminum hypophosphite or polyphenyl borate is used alone, it cannot achieve a good flame retardant effect. In Comparative Example 2, when the addition amount of aluminum hypophosphite is increased to 13 parts, the molten drop is suppressed and the UL-94 grade is V-2. However, due to the lack of carbon-forming substances, no carbon layer is generated on the polymer surface. There is a very serious smoke release phenomenon during the combustion of the sample, which poses a great safety hazard in real life. When 13 parts of polyphenyl borate is added alone in Comparative Example 1, although the smoke release is reduced, it shows that a carbon layer is generated on the sample surface, which hinders the release of smoke, but due to the formation of the carbon layer, the smoke release is greatly reduced. The structure is sparse and porous, resulting in a small decrease in smoke emission. In the UL-94 test, the sample only reached the V-2 level and was accompanied by dripping. This is due to the lack of the endothermic effect of the high-temperature decomposition of aluminum hypophosphite and the cross-linking effect of the metal ions. The density of the generated carbon layer is not enough to support the melt, resulting in dripping. When the two are used in combination, 1 part of polyphenyl borate can play a carbonizing role, slightly reducing the smoke emission of the sample in the cone calorimetry test. As the addition of polyphenyl borate increases to 5 parts, the carbonization amount also increases. However, the cross-linking effect of the metal ions is not enough to support the mass of the melt and the carbon layer, which easily causes dripping of the melt. When 10 parts of aluminum hypophosphite are used in combination with 3 parts of polyphenyl borate, not only can the UL-94 V-0 level be achieved, but the release of smoke can also be significantly suppressed.

[0030] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection defined by the claims.

[0031] Any matters not described in detail in the present invention are well-known technologies to those skilled in the art.

Claims

1. A flame retardant and smoke suppressant, characterized in that: The invention comprises the following components in parts by weight: 1 to 6 parts of borate polymer and 10 to 15 parts of phosphorus flame retardant.

2. The flame retardant and smoke suppressant according to claim 2, characterized in that: The composition comprises 3 parts by weight of borate polymer and 10 parts by weight of aluminum hypophosphite.

3. The flame retardant and smoke suppressant according to claim 1, characterized in that: The preparation method of the borate ester polymer comprises the following steps: S1. Dissolve a phenylboronic acid ester monomer and an initiator in an organic solvent, then transfer the mixture to a flask and stir at room temperature until transparent to obtain a solution A, wherein the mass ratio of the benzoic acid ester monomer to the initiator is 10-20:1, and the volume of the organic solvent is 20-80 mL / g based on the mass of the phenylboronic acid monomer; S2. Add a polyhydroxy compound dropwise to solution A at a rate of 0.56-3.3 mL / min, heat to reflux temperature under stirring, and react for 24 hours. The resulting reaction solution B is filtered and washed with toluene to obtain a borate polymer, wherein the mass ratio of the polyhydroxy compound to the phenyl borate monomer is 1:1-3, the stirring speed is 200-2000 rpm, and the reflux temperature is 90-180°C.

4. The flame retardant and smoke suppressant according to claim 3, characterized in that: The phenyl borate monomer is one or more of phenylboronic acid, 3-aminophenylboronic acid, and p-methylphenylboronic acid.

5. The flame retardant and smoke suppressant according to claim 3, characterized in that: The initiator is one or more of lithium chloride, azobisisobutyronitrile, and ditoluoyl peroxide.

6. The flame retardant and smoke suppressant according to claim 3, characterized in that: The organic solvent is one or more of toluene, dichloromethane and chloroform.

7. The flame retardant and smoke suppressant according to claim 3, characterized in that: The polyhydroxy compound is one or more of diethanolamine, ethylene glycol, and glycerol.

8. A polyvinyl chloride, characterized in that The invention comprises the following components in parts by weight: 100 parts of PVC resin, 40 parts of plasticizer, 10-20 parts of flame retardant and smoke suppressant, 3-6 parts of heat stabilizer, and 0.3-0.6 parts of lubricant, wherein the flame retardant and smoke suppressant is the flame retardant and smoke suppressant according to any one of claims 1 to 7.

9. The polyvinyl chloride according to claim 8, characterized in that: The heat stabilizer is one of dibasic lead phosphite and barium stearate or a mixture of the two.

10. The polyvinyl chloride according to claim 8, characterized in that: The lubricant is one of paraffin and stearic acid or a mixture of the two.

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