阅读说明：本技术 一种新型哌嗪焦磷酸盐阻燃剂及其制备方法 (Novel piperazine pyrophosphate flame retardant and preparation method thereof ) 是由 方孝汉 于 2021-01-07 设计创作，主要内容包括：本发明公开一种新型哌嗪焦磷酸盐阻燃剂及其制备方法,包括如下步骤：步骤一,按照质量份数,将蒸馏水、哌嗪基单体、磷酸加入反应釜中,加热反应液至80-90～oC,反应2h,然后将温度降低至0-5～oC,析出白色晶体,得到焦磷酸盐哌嗪粉末；再与丙烯酸铜,(2,7-辛二烯-1-基)琥珀酸酐发生表面聚合反应,得到一种新型哌嗪焦磷酸盐阻燃剂。(The invention discloses a novel piperazine pyrophosphate flame retardant and a preparation method thereof, wherein the preparation method comprises the following steps: step one, adding distilled water, a piperazinyl monomer and phosphoric acid into a reaction kettle according to parts by weight, and heating reaction liquid to 80-90% o C, reacting for 2 hours, and then reducing the temperature to 0-5 o C, precipitating white crystals to obtain pyrophosphate piperazine powder; then carrying out surface polymerization reaction with copper acrylate and (2, 7-octadiene-1-yl) succinic anhydride to obtain the novel piperazine pyrophosphate flame retardant.)

1. A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

step one, adding 120 parts by mass of distilled water of 100 plus materials, 15-18 parts by mass of piperazine monomers and 34-41 parts by mass of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring for 30-60min at 200r/min of 100 plus materials to fully dissolve the materials, heating the reaction solution to 80-90-^oC, reacting for 2-3h, and then reducing the temperature to 0-5^oC, separating out white crystals, washing with ice distilled water, carrying out vacuum filtration to obtain white crystals, then putting the obtained white crystals into a conical dryer, and adding 100-110-^oC drying for 2-4h, removing water, transferring the powder into a vacuum kneader, and raising the temperature to 220-^oC, preserving the heat for 30-60min, and then cooling to room temperature to obtain pyrophosphate piperazine powder;

step two, according to the mass parts, 3-9 parts of diallylamine, 30-35 parts of pyrophosphate piperazine powder, 100-120 parts of distilled water, 0.5-1.8 parts of dispersing agent, 0.5-1.8 parts of dispersion stabilizer and 70-90 parts of^oC, reacting for 0.5-2 h;

step three, adding 2-5 parts of copper acrylate and 0.1-0.5 part of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, then adding 0.1-0.5 part of ammonium persulfate, then increasing the rotating speed to 5000-10000r/min, keeping the speed for 10-20min, and then adding the mixture into a reactorReducing the rotation speed to 100-^oC, reacting for 2-4h, washing, filtering, placing in an oven, heating to 110-120-^oAnd C, preserving the heat for 4-8 hours to obtain the novel piperazine pyrophosphate flame retardant.

2. The method of claim 1, wherein the piperazinyl monomer in step one is one or more selected from piperazine, 2-piperazinone, 2-piperazinecarboxylic acid, and piperazine-2-methanol.

3. The method according to claim 1, wherein the dispersant in step two is one or more of nonylphenol polyoxyethylene ether, sodium dodecyl sulfate, sodium polynaphthalene formaldehyde sulfonate and sodium lignosulfonate.

4. The method according to claim 1, wherein the dispersion stabilizer in the second step is one or more of fumed silica, organic bentonite, carboxymethyl cellulose and polyvinyl alcohol.

5. The method according to claim 1, wherein the catalyst in the second step is one or more of stannous oxide, neodymium trifluoromethanesulfonate, zinc acetate and tetrabutyl titanate.

6. The method according to claim 1, wherein the pH regulator in step two is one or more selected from fumaric acid, tartaric acid, citric acid, and glacial acetic acid.

Technical Field

The invention relates to the field of flame retardants, and particularly relates to a novel piperazine pyrophosphate flame retardant and a preparation method thereof.

Background

With the continuous popularization of the application of the high polymer material technology, the high polymer material gradually replaces various metal and inorganic non-metal materials with higher cost performance, and gradually enters thousands of households.

At present, flame retardant modification of high polymer materials is mainly carried out by adding flame retardant into the materials, and the flame retardant can be divided into halogen flame retardant and halogen-free flame retardant according to whether the flame retardant contains halogen or not. The halogen flame retardant mainly comprises chlorine flame retardant and bromine flame retardant, such as decabromodiphenylethane, dodecabromodiphenyl oxide and the like, has low price and high flame retardant efficiency, and is widely applied in the past, but the halogen flame retardant has the great disadvantage that a large amount of toxic and harmful gas is generated in the flame retardant process, and the life health of people is harmed. The halogen-free flame retardant mainly comprises phosphorus flame retardants, nitrogen flame retardants and organic silicon flame retardants, is environment-friendly, and has low toxicity of salt mist generated in the flame retardant process, but the halogen-free flame retardant has low flame retardant efficiency. Therefore, the development of environment-friendly halogen-free flame retardant with high flame retardant efficiency is the research direction in the field of flame retardance at present.

The piperazine phosphate flame retardant simultaneously contains phosphorus and nitrogen, the phosphorus promotes the polymer material to form a compact carbon layer in the combustion process, and the nitrogen promotes the polymer material to generate gas in the combustion process to dilute free radicals in the combustion process, so that phosphorus and nitrogen play a role in flame retardant synergy, and the flame retardant efficiency is greatly improved. Therefore, the research on how to prepare the piperazine phosphate flame retardant and better apply the piperazine phosphate flame retardant to the flame retardance of high polymer materials has great significance.

CN202010686157.X discloses a fine-grained piperazine polyphosphate flame retardant, the grain size D50 of which is less than 20 μm; the invention also discloses a preparation method of the fine-grained piperazine polyphosphate fire retardant, which comprises the steps of adding acetic acid into a reaction device, adding piperazine under the stirring condition, and heating; adding polyphosphoric acid, stirring, and reacting at the temperature of 100-; and cooling to room temperature, filtering and drying to obtain the polyphosphoric acid piperazine flame retardant with fine particle size. The method can be used for directly preparing the piperazine polyphosphate flame retardant with a fine particle size, the product can be used without a crushing process after being dried, and the acetic acid filtrate obtained by filtering after the reaction can be directly used for the next reaction without being processed.

CN202010529830.9 discloses a polyphosphoric acid piperazine composite flame retardant, which comprises the following components in percentage by mass: 87.1 to 99.4 percent of polyphosphoric acid piperazine, 0.5 to 7.1 percent of silane coupling agent and 0.1 to 5.8 percent of antioxidant; the silane coupling agent is coated on the outer layer of polyphosphoric acid piperazine; the invention also discloses a preparation method of the polyphosphoric acid piperazine compound flame retardant, wherein phosphoric acid aqueous solution and piperazine are added into a reaction device and stirred; introducing protective gas, adding an antioxidant, raising the temperature, and performing dehydration condensation reaction to prepare polyphosphoric acid piperazine; cooling, adding a silane coupling agent, mixing and coating, and discharging; the method has the advantages of high yield, low cost and easy operation, and the polyphosphoric acid piperazine composite flame retardant prepared by the method has high whiteness, good water resistance, high flame retardant efficiency and good material compatibility.

CN201811503034.7 discloses a piperazine-containing phosphorus-nitrogen based halogen-free flame retardant, a preparation method and application thereof; the molecular formula of the flame retardant is C10H21N2O2PS, and the structural formula is as follows: prepared by amidation reaction of 2-sulfo-2-chloro-5, 5-dimethyl-1, 3, 2-dioxaphosphorinane and N-methylpiperazine; it can be used as raw material additive for flame-retarding cellulose, polyester, polyurethane and polyolefine fibre or film or as main function substance of flame-retarding coating layer. The flame retardant is an additive flame retardant containing nitrogen and phosphorus flame retardant components, and does not contain halogen; the preparation method adopts a two-step synthesis process, has mild reaction conditions and simple preparation process, and is suitable for industrial large-scale production.

In the prior art, although phosphate piperazine is successfully prepared by a piperazine phosphate flame retardant preparation technology, the compatibility of the flame retardant and a plastic matrix is poor, and the flame retardant is easy to agglomerate, so that the dispersibility of the flame retardant in the plastic matrix is poor, the flame retardant efficiency is reduced, other performances of the plastic matrix are greatly reduced after flame retardant modification, and the further application of the piperazine flame retardant is limited. Therefore, the development of the piperazine pyrophosphate flame retardant which has good compatibility with a plastic matrix and high flame retardant efficiency is of great significance.

Disclosure of Invention

The piperazine pyrophosphate flame retardant obtained by the invention has better compatibility with a plastic substrate, better dispersibility in the substrate, higher flame retardant efficiency and smaller influence on the mechanical property of the plastic substrate.

A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

step one, adding 120 parts by mass of distilled water, 15-18 parts by mass of piperazine monomer and 34-41 parts by mass of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring for 30-60min at 200r/min of 100 plus materials to fully dissolve the materials, heating the reaction liquid to 80-90 ℃, reacting for 2-3h, then reducing the temperature to 0-5 ℃, separating out white crystals, washing with distilled water, carrying out vacuum filtration to obtain white crystals, then placing the obtained white crystals into a conical drier, drying for 2-4h at 110 ℃ of 100 plus materials, removing moisture, transferring the powder into a vacuum kneader, increasing the temperature to 240 ℃ of 220 plus materials, preserving heat for 30-60min, and then cooling to room temperature to obtain piperazine pyrophosphate powder;

step two, reacting 3-9 parts of diallylamine, 30-35 parts of pyrophosphate piperazine powder, 100-120 parts of distilled water, 0.5-1.8 parts of dispersing agent, 0.5-1.8 parts of dispersion stabilizer and 70-90 ℃ for 0.5-2h according to parts by mass;

step three, adding 2-5 parts of copper acrylate and 0.1-0.5 part of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, then adding 0.1-0.5 part of ammonium persulfate, then increasing the rotating speed to 10000-.

Preferably, the piperazinyl monomer in the step one is one or a combination of piperazine, 2-piperazinone, 2-piperazinecarboxylic acid and piperazine-2-methanol.

Preferably, the dispersant in the second step is one or a combination of several of nonylphenol polyoxyethylene ether, sodium dodecyl sulfate, sodium polynaphthalene formaldehyde sulfonate and sodium lignosulfonate.

Preferably, the dispersion stabilizer in the second step is one or a combination of fumed silica, organic bentonite, carboxymethyl cellulose and polyvinyl alcohol.

Preferably, the catalyst in the second step is one or a combination of stannous oxide, neodymium trifluoromethanesulfonate, zinc acetate and tetrabutyl titanate.

Preferably, the PH regulator in step two is one or a combination of fumaric acid, tartaric acid, citric acid and glacial acetic acid.

Part of reaction mechanism in the preparation process of the novel piperazine pyrophosphate flame retardant is shown as follows:

then carrying out surface polymerization reaction with copper acrylate and (2, 7-octadiene-1-yl) succinic anhydride to obtain the novel piperazine pyrophosphate flame retardant.

Compared with the prior art, the invention has the beneficial effects that:

1. by adding the surfactant and the stabilizer into the formula system, the obtained flame retardant powder particles are smaller, so that the dispersing performance of the flame retardant in the plastic is better, and the flame retardant performance and the mechanical performance of the plastic are improved.

2. By carrying out surface polymerization reaction on copper acrylate and (2, 7-octadiene-1-yl) succinic anhydride on the surface of piperazine, the compatibility of the piperazine flame retardant and a matrix is greatly improved, so that the dispersion performance of the piperazine flame retardant in plastics is greatly improved, and the performance and the mechanical performance of the plastics are improved.

Drawings

FIG. 1 is a Fourier infrared spectrum of the novel piperazine pyrophosphate flame retardant product obtained in example 1:

at 1236cm^-1The expansion and contraction absorption peak of phosphorus-oxygen double bond is present nearby and is 1072/837cm^-1An antisymmetric stretching/symmetric stretching absorption peak of a phosphorus-oxygen single bond exists nearby, which indicates that phosphoric acid participates in the reaction; at 2927cm^-1The expansion absorption peak of carbon-hydrogen bond is present nearby and is at 995cm^-1An absorption peak near a carbon-nitrogen single bond of 1787cm^-1Absorption peak of carboxycarbonyl group in the vicinityAt 3418cm^-1An absorption peak of carboxyl hydroxyl exists nearby, which indicates that 2-piperazine carboxylic acid participates in the reaction; at 1146cm^-1The antisymmetric telescopic absorption peak of ether bond exists nearby, which indicates that formaldehyde participates in the reaction; at 1581cm^-1A stretching absorption peak of carbon-nitrogen double bond exists nearby, which indicates that diallylamine participates in the reaction.

Detailed Description

The raw materials used in the following examples are all commercially available products, and the examples are further illustrative of the present invention and do not limit the scope of the present invention;

the performance test methods are as follows:

according to various performances of the flame retardant, 20% of flame retardant powder is added into epoxy resin to prepare novel piperazine pyrophosphate flame-retardant modified epoxy resin, and then the epoxy resin is tested, so that various performances of the flame retardant are evaluated.

1. The method for testing the particle size of the flame retardant comprises the steps of brittle fracture of the prepared flame-retardant epoxy sample strip, observation of the section morphology by using an SEM (scanning electron microscope), and testing of the particle size of flame retardant particles.

2. According to the LOI test method, a flame-retardant epoxy sample strip is prepared according to the standard of GB/T2406.8-2008 and is tested.

3. The vertical burning rating test method, according to UL94 standard preparation fire-retardant epoxy sample strip, test.

4. Tensile strength test method, according to the test standard of ASTM D638, test specimens of flame retardant epoxy were tested with a universal tester.

Example 1

A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

step one, adding 100kg of distilled water, 15kg of 2-piperazine carboxylic acid and 34kg of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring for 30min at 100r/min to fully dissolve the materials, heating the reaction solution to 80 ℃, reacting for 2h, then reducing the temperature to 0 ℃, precipitating white crystals, washing with ice distilled water, carrying out vacuum filtration to obtain white crystals, then putting the obtained white crystals into a conical drier, drying for 4h at 100 ℃, removing moisture, then transferring the powder into a vacuum kneader, raising the temperature to 220 ℃, preserving the temperature for 60min, and then cooling to room temperature to obtain pyrophosphate piperazine powder;

reacting 3kg of diallylamine, 30kg of pyrophosphate piperazine powder, 100kg of distilled water, 0.5kg of dispersing agent, 0.5kg of dispersion stabilizer and 0.5h at 70 ℃;

and step three, adding 2kg of copper acrylate and 0.1kg of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, adding 0.1kg of ammonium persulfate, increasing the rotating speed to 5000r/min, keeping the rotating speed for 10min, reducing the rotating speed to 100r/min, increasing the temperature of the reaction liquid to 80 ℃, reacting for 2h, washing and filtering, placing in an oven, heating to 110 ℃, and preserving heat for 4h to obtain the novel piperazine pyrophosphate flame retardant.

The particle size of the obtained flame retardant powder is 10 microns, the LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy is 30, the vertical combustion grade is V0 grade, and the tensile strength is 65 MPa.

Example 2

A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

step one, adding 109kg of distilled water, 15kg of 2-piperazinone and 35kg of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring for 36min at 133r/min to fully dissolve the materials, heating the reaction solution to 83 ℃, reacting for 2h, then reducing the temperature to 2 ℃, precipitating white crystals, washing with ice distilled water, carrying out vacuum filtration to obtain white crystals, then putting the obtained white crystals into a conical drier, drying for 3h at 103 ℃, removing moisture, then transferring the powder into a vacuum kneader, raising the temperature to 228 ℃, keeping the temperature for 47min, and then cooling to room temperature to obtain pyrophosphate piperazine powder;

reacting 4kg of diallylamine, 32kg of pyrophosphate piperazine powder, 104kg of distilled water, 0.7kg of dispersing agent, 0.8kg of dispersion stabilizer and 0.9h at 75 ℃;

and step three, adding 3kg of copper acrylate and 0.25kg of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, adding 0.2kg of ammonium persulfate, increasing the rotating speed to 6000r/min, keeping the rotating speed for 15min, reducing the rotating speed to 130r/min, increasing the temperature of the reaction liquid to 82 ℃, reacting for 2.5h, washing and filtering, placing in an oven, heating to 115 ℃, and preserving heat for 5h to obtain the novel piperazine pyrophosphate flame retardant.

The particle size of the obtained flame retardant powder is 6 microns, the LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy is 31, the vertical combustion grade is V0 grade, and the tensile strength is 66 MPa.

Example 3

A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

adding 115kg of distilled water, 15kg of piperazine and 37kg of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring at 176r/min for 47min to fully dissolve the materials, heating the reaction solution to 85 ℃, reacting for 2h, then reducing the temperature to 3 ℃, precipitating white crystals, washing with ice distilled water, carrying out vacuum filtration to obtain white crystals, then putting the obtained white crystals into a conical drier, drying at 106 ℃ for 2h, removing moisture, then transferring the powder into a vacuum kneader, raising the temperature to 235 ℃, preserving heat for 42min, and then cooling to room temperature to obtain pyrophosphate piperazine powder;

step two, reacting 7 powder, 0.9kg of dispersion stabilizer and 77 ℃ for 0.9 h;

and step three, adding 3kg of copper acrylate and 0.3kg of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, adding 0.3kg of ammonium persulfate, increasing the rotating speed to 7000r/min, keeping the rotating speed for 14min, reducing the rotating speed to 150r/min, increasing the temperature of the reaction liquid to 84 ℃, reacting for 3h, washing and filtering, placing in an oven, heating to 105 ℃, and preserving heat for 5h to obtain the novel piperazine pyrophosphate flame retardant.

The particle size of the obtained flame retardant powder is 4 microns, the LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy is 31, the vertical combustion grade is V0 grade, and the tensile strength is 67 MPa.

Example 4

A novel piperazine pyrophosphate flame retardant and a preparation method thereof are characterized by comprising the following steps:

adding 120kg of distilled water, 18kg of piperazine-2-methanol and 41kg of phosphoric acid into a reaction kettle, introducing nitrogen into the reaction kettle, fully removing air, stirring for 60min at 200r/min to fully dissolve the materials, heating the reaction solution to 90 ℃, reacting for 3h, then reducing the temperature to 5 ℃, separating out white crystals, washing with ice distilled water, carrying out vacuum filtration to obtain white crystals, then putting the obtained white crystals into a conical drier, drying for 2h at 110 ℃, removing moisture, then transferring the powder into a vacuum kneader, raising the temperature to 240 ℃, preserving the heat for 30min, and then cooling to room temperature to obtain pyrophosphate piperazine powder;

secondly, 9kg of diallylamine, 35kg of pyrophosphate piperazine powder, 120kg of distilled water, 1.8kg of dispersing agent, 1.8kg of dispersion stabilizer and 2 hours of reaction at 90 ℃;

and step three, adding 5kg of copper acrylate and 0.5kg of (2, 7-octadiene-1-yl) succinic anhydride, uniformly mixing, adding 0.5kg of ammonium persulfate, increasing the rotating speed to 10000r/min, keeping the rotating speed for 20min, reducing the rotating speed to 200r/min, increasing the temperature of the reaction liquid to 90 ℃, reacting for 4h, washing and filtering, placing in an oven, heating to 120 ℃, and preserving heat for 8h to obtain the novel piperazine pyrophosphate flame retardant.

The particle size of the obtained flame retardant powder is 0.5 micron, the LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy is 33, the vertical combustion grade is V0 grade, and the tensile strength is 71 MPa.

Comparative example 1

With respect to example 1, 0kg of nonylphenol polyoxyethylene ether was added, and the remainder was the same as in example 1, and the resulting flame retardant powder had a particle size of 50 μm, an LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy of 24, a vertical flame rating of V1, and a tensile strength of 55 MPa.

Comparative example 2

The amount of fumed silica added was 0kg with respect to example 1, and the remainder was in accordance with example 1, and the resulting flame retardant powder had a particle size of 36 μm, an LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy of 27, a vertical burning rating of V1, and a tensile strength of 58 MPa.

Comparative example 3

Relative to example 1, the second step is omitted, the obtained piperazine powder is directly added into epoxy resin, the rest is consistent with example 1, the particle size of the obtained flame retardant powder is 125 microns, the LOI of the novel piperazine pyrophosphate flame-retardant modified epoxy is 23, the vertical burning grade is V2 grade, and the tensile strength is 50 MPa.

Comparative example 4

The epoxy resin is not added with a flame retardant, the LOI of the epoxy resin is 19, the vertical burning grade is no grade, and the tensile strength is 72 MPa.