Piperazine pyrophosphate coating as well as preparation method and application thereof

Abstract

The invention discloses a piperazine pyrophosphate coating as well as a preparation method and application thereof, and belongs to the technical field of flame retardants. The piperazine pyrophosphate coating provided by the invention comprises a piperazine pyrophosphate inner core and a coating layer coating the surface of the piperazine pyrophosphate inner core, the coating layer comprises dipalmitoyl tartaric acid diester and a coupling agent, and the coupling agent is a titanate coupling agent and / or a zirconate coupling agent. According to the piperazine pyrophosphate coating disclosed by the invention, the surface of the piperazine pyrophosphate is coated with the coating layer comprising the dipalmitoyl tartaric acid diester and the coupling agent, so that the water resistance, the chemical stability and the precipitation resistance of the piperazine pyrophosphate coating are improved.

Description

Technical Field

[0001] The present application relates to the technical field of flame retardants, and in particular to a piperazine pyrophosphate coating, a preparation method and an application thereof. Background Art

[0002] Piperazine pyrophosphate (PAPP), a highly effective nitrogen-phosphorus halogen-free flame retardant, is widely used in flame retardant applications for materials such as plastics, rubber, and fibers due to its excellent thermal stability, high flame retardancy, and environmental friendliness. During combustion, it forms a stable char layer that effectively blocks the transfer of heat and oxygen, achieving a flame-retardant effect.

[0003] Piperazine pyrophosphate has significant drawbacks: the hydrophilic groups in its molecular structure result in high water solubility (a solubility of 2-3g / 100mL at room temperature). This high water solubility of piperazine pyrophosphate is closely linked to precipitation. When materials containing piperazine pyrophosphate are exposed to moisture or moisture, due to its water solubility, the piperazine pyrophosphate molecules gradually interact with water molecules and dissolve from the original material matrix. As the moisture evaporates or the environment within the material system changes, the piperazine pyrophosphate dissolved in water reaches a supersaturated state, precipitating from the solution as crystals. This precipitation not only affects the material's appearance, causing whitening and blooming, but also accumulates on the material's surface, preventing it from exerting its flame retardant properties within the material, further degrading its flame retardancy. Furthermore, the precipitated substances may affect the material's subsequent processing performance. For example, in injection molding, the precipitates may clog the mold's flow path, affecting molding quality. These issues severely restrict its application in applications with stringent durability requirements, such as electronics and automotive parts. In addition, the dissolution and loss of piperazine pyrophosphate may also pose potential pollution risks to the environment. Summary of the Invention

[0004] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a piperazine pyrophosphate coating and a preparation method and application thereof.

[0005] To achieve the above objectives, the technical solutions adopted by the present disclosure are as follows: In a first aspect, a piperazine pyrophosphate coating is provided, comprising a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core;

[0006] The coating layer comprises dipalmitoyl tartaric acid diester and a coupling agent, and the coupling agent is a titanate coupling agent and / or a zirconate coupling agent.

[0007] In some embodiments, the mass ratio of the piperazine pyrophosphate to the coating layer is 1:(0.3-1).

[0008] In some embodiments, the mass ratio of the dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.5-1.2).

[0009] In some embodiments, the coupling agent is a titanate coupling agent and a zirconate coupling agent; the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):1.

[0010] In some embodiments, the titanate coupling agent includes monoalkoxy titanate and / or neoalkoxy titanate.

[0011] In some embodiments, the monoalkoxy titanate includes at least one of isopropoxy triisostearyl titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate acrylamide chelate, tetraoctyl bis(dilauryl phosphite acyloxy) titanate, triethanolamine chelate of bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropoxy tri(dodecylbenzenesulfonyloxy) titanate, tetraisopropyl di(dioctyl phosphite acyloxy) titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropyl tri(branched and linear dioctyl phosphite acyloxy) titanate, isopropoxy dioleyl (dioctyl phosphite acyloxy) titanate, propoxy titanium tristearate, isopropoxy trioleyl titanate, and isopropoxy tri(ethylenediamino-N-ethoxy) titanate;

[0012] In some embodiments, the neoalkoxy titanate includes at least one of neoalkoxy tris (p-aminophenoxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate acrylamide chelate, neoalkoxy tris (diisooctyl phosphate) titanate, neoalkoxy tris (neodecanoyloxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate, and neoalkoxy tris (dioctyl phosphate) titanate.

[0013] In some embodiments, the zirconate coupling agent includes at least one of neoalkoxy tris(dioctyl phosphate) zirconate, neoalkoxy tris(dodecylbenzenesulfonyloxy) zirconate, neoalkoxy tris(neodecanoyloxy) zirconate, and neoalkoxy tris(dioctyl pyrophosphate) zirconate.

[0014] In some embodiments, the piperazine pyrophosphate core is formed of piperazine pyrophosphate, and the average particle size of the piperazine pyrophosphate is 10-50 μm.

[0015] In a second aspect, a method for preparing the piperazine pyrophosphate coating is provided, comprising the following steps:

[0016] preparing a first dispersion containing piperazine pyrophosphate;

[0017] preparing a second dispersion of dipalmitoyl tartaric acid diester and a coupling agent;

[0018] The second dispersion liquid is added to the first dispersion liquid, and ultrasonic dispersion is performed. The obtained suspension liquid is subjected to heating reaction, solid-liquid separation, and drying to obtain the piperazine pyrophosphate coated material.

[0019] In some embodiments, the heating reaction temperature is 60-80h and the time is 3-6h;

[0020] In some embodiments, the ultrasonic dispersion has a power of 200-400 W and a time of 10-30 min.

[0021] In a third aspect, a flame retardant composition is provided, which comprises the piperazine pyrophosphate coating or the piperazine pyrophosphate coating prepared by the method for preparing the piperazine pyrophosphate coating.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] (1) The piperazine pyrophosphate coating of the present application improves the water resistance, chemical stability and precipitation resistance of the piperazine pyrophosphate coating by coating the surface of the piperazine pyrophosphate with a coating layer including dipalmitoyl tartaric acid diester and a coupling agent, wherein the long-chain alkyl group in the dipalmitoyl tartaric acid diester molecule is adsorbed on the surface of the piperazine pyrophosphate by van der Waals force to form a hydrophobic outer film; its polar end (tartrate group) is combined with the polar group (such as pyrophosphate group, residual hydroxyl group) on the surface of the piperazine pyrophosphate by hydrogen bond and / or dipole interaction, and the long-chain alkyl group in the coupling agent and the long-chain alkyl group in the dipalmitoyl tartaric acid diester are interwoven through hydrophobic interaction to form an interpenetrating network structure, which together constitute a "double-layer hydrophobic barrier" to improve the water resistance of the piperazine pyrophosphate coating.

[0024] (2) In the present application, a second dispersion containing dipalmitoyl tartaric acid diester and a coupling agent is added to a first dispersion containing piperazine pyrophosphate. By heating reaction, the dipalmitoyl tartaric acid diester and the coupling agent are self-assembled into a coating layer on the surface of piperazine pyrophosphate. The coating layer has good chemical stability and water resistance, and can effectively improve the water resistance and anti-precipitation performance of the piperazine pyrophosphate coating.

[0025] (3) The present invention relates to a method for preparing a piperazine pyrophosphate coated material. The raw materials and solvents used are non-toxic and harmless. After the heating reaction, solid-liquid separation can effectively remove residual impurities and unreacted substances in the piperazine pyrophosphate coated material, thereby improving the purity of the piperazine pyrophosphate coated material and reducing environmental pollution. Furthermore, during application, the piperazine pyrophosphate coated material exhibits high stability and water resistance, reducing secondary pollution caused by precipitation. DETAILED DESCRIPTION

[0026] To facilitate understanding of the present disclosure, a more comprehensive description will be given below. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, the purpose of providing these embodiments is to provide a more thorough and comprehensive understanding of the disclosure of the present disclosure.

[0027] As used herein:

[0028] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0029] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0030] When amount, concentration or other value or parameter are represented with range, preferred range or the range that a series of upper preferred value and lower preferred value limit are expressed, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value and any range lower limit or preferred value, and no matter whether this scope is disclosed separately.For example, when disclosing scope " 1-5 ", described scope should be interpreted as including scope " 1-4 ", " 1-3 ", " 1-2 ", " 1-2 and 4-5 ", " 1-3 and 5 " etc.When numerical range is described in this article, unless otherwise stated, otherwise this scope is intended to include its end value and all integers and fractions within this range.

[0031] In these examples, parts and percentages are by mass unless otherwise indicated.

[0032] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. For example, if we say that the mass of component A is a parts and the mass of component B is b parts, this means the ratio of the mass of component A to the mass of component B is a:b. It should be noted that, unlike mass percentages, the sum of the mass of all components is not limited to 100 parts.

[0033] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0034] In a first aspect of the present application, a piperazine pyrophosphate coating is provided, comprising a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core;

[0035] The coating layer comprises dipalmitoyl tartaric acid diester and a coupling agent, and the coupling agent is a titanate coupling agent and / or a zirconate coupling agent.

[0036] In the pyrophosphate piperazine coating of the present application, a coating layer including dipalmitoyl tartaric acid diester and a coupling agent is coated on the surface of the pyrophosphate piperazine to improve the water resistance, thermal stability and precipitation resistance of the pyrophosphate piperazine coating, wherein the long-chain alkyl group in the dipalmitoyl tartaric acid diester molecule is adsorbed on the surface of the pyrophosphate piperazine through van der Waals force to form a hydrophobic outer film; its polar end (tartrate group) is combined with the polar group (such as pyrophosphate group, residual hydroxyl group) on the surface of the pyrophosphate piperazine through hydrogen bonds and / or dipole interactions, and the long-chain alkyl group in the coupling agent and the long-chain alkyl group in the dipalmitoyl tartaric acid diester are interwoven through hydrophobic interactions to form an interpenetrating network structure, which together constitute a "double-layer hydrophobic barrier" to improve the water resistance and thermal stability of the pyrophosphate piperazine coating.

[0037] In some embodiments, the mass ratio of the piperazine pyrophosphate to the coating layer is 1:(0.3-1), for example, but not limited to 1:0.3, 1:0.4, 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.9, 1:1.0, preferably 1:(0.5-0.8).

[0038] The applicant found that when the mass ratio of piperazine pyrophosphate to the coating layer is 1:(0.3-1), the obtained piperazine pyrophosphate coating has higher water resistance, hydrophobic durability, mechanical properties and thermal stability.

[0039] When the mass ratio of piperazine pyrophosphate to the coating layer is less than 0.3, it is easy to cause insufficient coating and insufficient cross-linking of the coupling agent, resulting in defects in the coating layer, making the surface of the piperazine pyrophosphate core incompletely covered, and thus leading to poor water resistance and hydrophobic durability of the piperazine pyrophosphate coating; when the mass ratio of piperazine pyrophosphate to the coating layer is greater than 1, the coating is excessive, and the coating layer is physically accumulated in multiple layers, which leads to a decrease in the mechanical properties of the piperazine pyrophosphate coating; at a mass ratio of 1:(0.3-1), the coating layer is a single-layer structure, and the long-chain alkyl group of the coupling agent and the dipalmitoyl C16 chain form a woven shape to obtain a densely covered coating layer, thereby improving the water resistance, hydrophobic durability, mechanical properties and thermal stability of the piperazine pyrophosphate coating.

[0040] In some embodiments, the mass ratio of the dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.5-1.2), for example, but not limited to 1:0.5, 1:0.6, 1:0.7, 1:0.8, 1:0.39, 1:1.0, 1:1.1, 1:1.2; preferably 1:(0.7-1).

[0041] The applicant found that when the mass ratio of dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.5-1.2), the obtained piperazine pyrophosphate coating has higher water resistance, hydrophobic durability, mechanical properties and thermal stability.

[0042] In some embodiments, the coupling agent is a titanate coupling agent and a zirconate coupling agent; the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):1, for example, but not limited to 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1; preferably (4-6):1.

[0043] The applicant found that when the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):1, the resulting piperazine pyrophosphate coating has higher water resistance, hydrophobic durability, mechanical properties and thermal stability.

[0044] When the mass ratio of titanate coupling agent to zirconate coupling agent is less than 2:1, the excessive zirconate leads to large steric hindrance of the side chains, which can easily lead to excessive rigidity of the coating layer and reduced impact strength. In addition, the long titanate chains are constrained, and the hydrophobic network cannot fully extend, which in turn leads to a decrease in the hydrophobic properties of the piperazine pyrophosphate coating. When the mass ratio of titanate coupling agent to zirconate coupling agent is greater than 8:1, the titanate ratio is too high. In this case, the hydrolysis side reaction dominates, the Ti-OH group absorbs water, and the unreacted titanate catalyzes the decomposition of piperazine pyrophosphate, resulting in a decrease in the thermal stability of the piperazine pyrophosphate coating.

[0045] In some embodiments, the titanate coupling agent includes monoalkoxy titanate and / or neoalkoxy titanate.

[0046] In some embodiments, the monoalkoxy titanate includes at least one of isopropoxy triisostearyl titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate acrylamide chelate, tetraoctyl bis(dilauryl phosphite) titanate, triethanolamine chelate of bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropoxy tri(dodecylbenzenesulfonyloxy) titanate, tetraisopropyl di(dioctyl phosphite) titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropyl tri(branched and linear dioctyl phosphite) titanate, isopropoxy dioleyl (dioctyl phosphite) titanate, propoxy titanium tristearate, isopropoxy trioleyl titanate, and isopropoxy tri(ethylenediamino-N-ethoxy) titanate.

[0047] In some embodiments, the neoalkoxy titanate includes at least one of neoalkoxy tris (p-aminophenoxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate acrylamide chelate, neoalkoxy tris (diisooctyl phosphate) titanate, neoalkoxy tris (neodecanoyloxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate, and neoalkoxy tris (dioctyl phosphate) titanate.

[0048] In some embodiments, the zirconate coupling agent includes at least one of neoalkoxy tris(dioctyl phosphate) zirconate, neoalkoxy tris(dodecylbenzenesulfonyloxy) zirconate, neoalkoxy tris(neodecanoyloxy) zirconate, and neoalkoxy tris(dioctyl pyrophosphate) zirconate.

[0049] Preferably, the titanate coupling agent is at least one of bis(dioctyl pyrophosphate)ethylene titanate acrylamide chelate, bis(dioctyl pyrophosphate)ethylene titanate triethanolamine chelate, bis(dioctyl pyrophosphate)ethylene titanate, neoalkoxy tris(dioctyl pyrophosphate) titanate acrylamide chelate, neoalkoxy tris(diisooctyl phosphate) titanate, neoalkoxy tris(dioctyl pyrophosphate) titanate, and neoalkoxy tris(dioctyl phosphate) titanate.

[0050] Preferably, the zirconate coupling agent includes at least one of neoalkoxy tris(dioctyl phosphate) zirconate and neoalkoxy tris(dioctyl pyrophosphate) zirconate.

[0051] In some embodiments, the molecular structures of both the titanate coupling agent and the zirconate coupling agent contain pyrophosphate acyloxy groups. When the molecular structures of both the titanate coupling agent and the zirconate coupling agent contain pyrophosphate acyloxy groups, the pyrophosphate acyloxy groups are partially hydrolyzed in a solvent (such as ethanol) to generate active hydroxyl groups. The active hydroxyl groups undergo condensation reactions with the hydroxyl groups or pyrophosphate groups on the surface of piperazine pyrophosphate to form covalent bonds, thereby improving the stability of piperazine pyrophosphate, thereby improving the water resistance, hydrophobic durability, mechanical properties and thermal stability of the piperazine pyrophosphate coating.

[0052] In some embodiments, the piperazine pyrophosphate core is formed by piperazine pyrophosphate, and the average particle size of the piperazine pyrophosphate is 10-50 μm, for example, but not limited to 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 43 μm, 45 μm, 48 μm, 50 μm; preferably 20-40 μm.

[0053] The applicant has found that when the average particle size of piperazine pyrophosphate is 10-50 μm, the resulting piperazine pyrophosphate coating has higher water resistance, hydrophobic durability, mechanical properties and thermal stability.

[0054] Specifically, the average particle size of piperazine pyrophosphate is obtained by testing according to the following method: piperazine pyrophosphate is dispersed in an aqueous solution, the morphology of piperazine pyrophosphate is characterized using a scanning electron microscope (SEM), and 100 piperazine pyrophosphate particles are counted to obtain the average particle size of piperazine pyrophosphate.

[0055] In a second aspect of the present application, a method for preparing the piperazine pyrophosphate coating is provided, comprising the following steps:

[0056] preparing a first dispersion containing piperazine pyrophosphate;

[0057] preparing a second dispersion containing dipalmitoyl tartaric acid diester and a coupling agent;

[0058] The second dispersion liquid is added to the first dispersion liquid, and ultrasonic dispersion is performed. The obtained suspension liquid is subjected to heating reaction, solid-liquid separation, and drying to obtain the piperazine pyrophosphate coated material.

[0059] In the present application, a second dispersion containing dipalmitoyl tartaric acid diester and a coupling agent is added to a first dispersion containing piperazine pyrophosphate. Through a heating reaction, the dipalmitoyl tartaric acid diester and the coupling agent self-assemble into a coating layer on the surface of the piperazine pyrophosphate. The coating layer has good chemical stability and water resistance, and can effectively improve the water resistance, hydrophobic durability, mechanical properties and thermal stability of the piperazine pyrophosphate coating.

[0060] The present invention discloses a method for preparing a piperazine pyrophosphate coated material using non-toxic and harmless raw materials and solvents. Furthermore, after the heating reaction, solid-liquid separation can effectively remove residual impurities and unreacted substances in the piperazine pyrophosphate coated material, thereby improving the purity of the piperazine pyrophosphate coated material and reducing environmental pollution. Furthermore, during application, the piperazine pyrophosphate coated material exhibits high thermal stability and water resistance, reducing secondary pollution caused by precipitation.

[0061] In some embodiments, the temperature of the heating reaction is 60-80°C, for example, but not limited to 60°C, 62°C, 65°C, 67°C, 70°C, 73°C, 75°C, 78°C, 80°C; the time is 3-6h, for example, but not limited to 3h, 4h, 5h, 6h.

[0062] The preparation method of the piperazine pyrophosphate coating of the present application is simple, the reaction conditions are mild, no complicated equipment and harsh reaction environment are required, and the production time is short, which greatly improves production efficiency, shortens the production cycle, reduces production energy consumption, and improves economic benefits.

[0063] In some embodiments, the ultrasonic dispersion has a power of 200-400 W and a time of 10-30 min.

[0064] Specifically, the steps of preparing the first dispersion containing piperazine pyrophosphate are:

[0065] Piperazine pyrophosphate is added into a first solvent and dispersed uniformly to obtain a first dispersion; the first solvent is selected from at least one of water, ethanol and methanol.

[0066] Specifically, the steps of preparing the second dispersion containing dipalmitoyl tartaric acid diester and a coupling agent are:

[0067] Adding dipalmitoyl tartaric acid diester and a coupling agent into a second solvent and dispersing them uniformly to obtain a second dispersion; the second solvent is selected from at least one of water, ethanol and methanol.

[0068] In order to improve the dispersibility of dipalmitoyl tartaric acid diester and coupling agent, the preparation method of the second dispersion is as follows:

[0069] First, dipalmitoyl tartaric acid diester is added to a first solvent, heated to dissolve, and then a coupling agent is added and stirred evenly to obtain a second dispersion.

[0070] Specifically, the temperature for heating and dissolving is 50-60°C, for example, but not limited to, 50°C, 52°C, 54°C, 56°C, 58°C, and 60°C.

[0071] Specifically, dipalmitoyl tartaric acid diester can be purchased commercially or prepared using a preparation method known in the art.

[0072] For example, add 10.5 g of palmitic acid to a round-bottom flask, add 10 mL of thionyl chloride dropwise, heat to 75-95 ° C after the addition is complete, react for 2-4 hours until the solution becomes transparent, remove excess thionyl chloride by rotary evaporation under reduced pressure, add 5 mL of methyl tert-butyl ether and continue rotary evaporation to obtain brown palmitoyl chloride;

[0073] Palmitoyl chloride was dissolved in dichloromethane and transferred to a three-necked flask. 16.8 mL of triethylamine was added under ice-water bath conditions. 3.0 g of tartaric acid was weighed, dissolved in acetone by heating, and then added dropwise to the three-necked flask. After the addition was complete, the temperature was raised to room temperature and the reaction was allowed to proceed overnight. The obtained reaction product was filtered, and the filtrate was evaporated under reduced pressure to obtain a paste-like solid crude product, which was recrystallized twice with acetone and dried to obtain disalmitoyl tartaric acid diester.

[0074] In a third aspect of the present application, a flame retardant composition is provided, which comprises the piperazine pyrophosphate coating or the piperazine pyrophosphate coating prepared by the method for preparing the piperazine pyrophosphate coating.

[0075] Specifically, the flame retardant composition includes a resin matrix; a piperazine pyrophosphate coating is added to the resin matrix, and the organic end (such as isopropoxy) of the coupling agent in the piperazine pyrophosphate coating is connected to the resin matrix, thereby improving the dispersibility of the piperazine pyrophosphate in the resin matrix, thereby improving the flame retardancy and mechanical properties of the flame retardant product.

[0076] Specific examples of the resin matrix include: α-olefin polymers such as polypropylene, high-density polyethylene, low-density polyethylene, linear low-density polyethylene, polybutene-1, poly-3-methylpentene, or polyolefins such as ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, and copolymers thereof, polyvinyl chloride, polyvinylidene chloride, chlorinated polyethylene, chlorinated polypropylene, polyvinylidene fluoride, chlorinated rubber, vinyl chloride-vinyl acetate copolymer, vinyl chloride-ethylene copolymer, vinyl chloride-vinylidene chloride copolymer, vinyl chloride-vinylidene chloride-vinyl acetate terpolymer, vinyl chloride-acrylate copolymer, vinyl chloride-maleate copolymer, vinyl chloride-cyclohexylmaleimide copolymer, and other halogen-containing resins, petroleum resins, coumarone resins, polystyrene, polyvinyl acetate, acrylic resins, styrene and / or copolymers of α-methylstyrene and other monomers (e.g., maleic anhydride, phenylmaleimide, methyl methacrylate, butadiene, acrylonitrile, etc.) (e.g., AS resin, ABS resin, MBS resin, heat-resistant ABS resin, etc.), linear polyesters such as polymethyl methacrylate, polyvinyl alcohol, polyvinyl formal, polyvinyl butyral, polyethylene terephthalate and polybutylene terephthalate, polyamides such as polyphenylene ether, polycaprolactam and polyhexamethylene adipamide, polycarbonate, polycarbonate / ABS resin, branched polycarbonate, polyacetal, polyphenylene sulfide, polyurethane, cellulose resin and the like, and mixtures thereof, or thermosetting resins such as phenolic resin, urea resin, melamine resin, epoxy resin, and unsaturated polyester resin, and polypropylene resin is particularly preferred.

[0077] When using the piperazine pyrophosphate coating of the present invention as a flame retardant, relative to 100 weight portions of the above-mentioned resin matrix, the addition of the piperazine pyrophosphate coating is preferably 20-60 weight portions. In addition, together with the piperazine pyrophosphate coating of the present invention, other flame retardants such as melamine pyrophosphate, piperazine polyphosphate, melamine polyphosphate, polyphosphoric acid amide, phosphoric acid ester, phosphoric acid ester amide, and compounding agents such as polysiloxane compounds, metal oxides, silicon dioxide, and higher aliphatic carboxylic acids can be used in combination. At this point, relative to 100 weight portions of the piperazine pyrophosphate coating of the present invention, the addition of other flame retardants is preferably 50-400 weight portions, and relative to 100 weight portions of the above-mentioned resin matrix, the addition of compounding agent is preferably 0.05-20 weight portion. In addition, they can also be pre-mixed and added to the above-mentioned resin matrix as a flame retardant composition.

[0078] The flame-retardant composition comprising the resin matrix and the piperazine pyrophosphate coating is formed into a molded article using conventional molding methods such as injection molding, extrusion molding, and inflation molding. This molded article is also one embodiment of the present invention. The molded article of the present invention is not limited in shape, and examples thereof include power plugs, connectors, sleeves, boxes, wire sheaths, tape substrates, tubes, sheets, and films.

[0079] Furthermore, when obtaining injection-molded articles such as wire components as the molded articles of the present invention, injection molding can be performed at a barrel temperature of approximately 190° C. and a head temperature of approximately 190° C. Molding can be performed using an injection molding machine commonly used for molding PVC resins, etc.

[0080] The raw materials used in the examples and comparative examples are described below, but are not limited to these materials:

[0081] Piperazine pyrophosphate was prepared in-house. The preparation method was as follows: 40 mL of deionized water and 43.07 g (0.5 mol) of anhydrous piperazine were added to a 250 mL three-necked flask equipped with a stirrer, a thermometer, a condenser, and a dropping funnel. The mixture was heated to about 40° C. and stirred to dissolve. After complete dissolution, 115.3 g (1.0 mol) of an 85% phosphoric acid solution was added dropwise over a period of about 1 hour. The mixture was heated to 85° C. and reacted for 2 hours. The mixture was cooled to room temperature and filtered. The filter cake was washed three times with 30 mL of deionized ice water each time. The washed filter cake was dried under vacuum until the mass remained constant to obtain piperazine diphosphate.

[0082] 100 g of piperazine diphosphate and 4.5 g of catalyst were added to a 500 mL beaker equipped with a stirrer and a thermometer. The materials were heated to 200° C. in an oil bath and reacted for 5 h. The mixture was then cooled to room temperature and pulverized with a universal grinder to obtain a crude product. The pulverized crude product and methanol were added to a beaker in a mass ratio of 1:1, stirred at room temperature for 0.5 h, and vacuum filtered. The filter cake was washed with a small amount of methanol, and then the washed filter cake was dried under vacuum conditions until the mass was constant to obtain piperazine pyrophosphate.

[0083] Disalmitoyl tartaric acid diester is homemade, and its preparation method is as follows: take 10.3g of palmitic acid in a round-bottom flask, add 10mL of thionyl chloride dropwise at a rate of 1s / drop under stirring, and after the addition is complete, heat to 80℃ and react for 3h until the solution becomes transparent; the obtained product is subjected to reduced pressure rotary evaporation to remove excess thionyl chloride, and then 5mL of methyl tert-butyl ether is added and rotary evaporation is continued to obtain brown-yellow palmitoyl chloride; the obtained palmitoyl chloride is dissolved in dichloromethane and transferred to a three-necked flask, and 16.8mL of triethylamine is added under ice-water bath conditions; 3.0g of tartaric acid is weighed, dissolved in acetone by heating, and then added dropwise to the three-necked flask, and after the addition is complete, heat to 25℃ and react overnight; filter, and the filtrate is subjected to reduced pressure rotary evaporation to obtain a paste-like solid crude product, which is recrystallized twice from acetone and dried to obtain a white solid, which is the target product, disalmitoyl tartaric acid diester.

[0084] Titanate coupling agent and zirconate coupling agent were purchased from Nanjing Nengde New Material Technology Co., Ltd.

[0085] Example 1

[0086] This embodiment provides a piperazine pyrophosphate coating, comprising a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core;

[0087] The coating layer includes dipalmitoyl tartaric acid diester and a coupling agent, wherein the coupling agent is isopropoxy trioleyl titanate;

[0088] Based on 10 parts by weight of piperazine pyrophosphate, the weight of dipalmitoyl tartaric acid diester is 2.5 parts, and the weight of the coupling agent is 2.5 parts;

[0089] The average particle size of piperazine pyrophosphate was 20 μm.

[0090] The preparation method of the piperazine pyrophosphate coating of this embodiment comprises the following steps:

[0091] 10 parts by weight of piperazine pyrophosphate having an average particle size of 20 μm was added to 100 parts by volume of an ethanol / water solution, wherein the volume ratio of ethanol to water in the ethanol / water solution was 1:1, and stirred to obtain a first dispersion;

[0092] 2.5 parts by weight of dipalmitoyl tartaric acid diester was added to 50 parts by volume of ethanol, and the mixture was stirred at 50° C. and 800 rpm to dissolve. Then, 2.5 parts by weight of a coupling agent was added, and the mixture was stirred at 800 rpm for 35 minutes to obtain a second dispersion.

[0093] The second dispersion was added to the first dispersion, and ultrasonic dispersion was performed at an ultrasonic power of 200 W for 15 minutes to obtain a suspension. The suspension was reacted at a temperature of 60°C and a rotation speed of 800 rpm for 4 hours. The reaction product was centrifuged, and the precipitate obtained by centrifugation was washed three times with ethanol, and then dried in a vacuum drying oven at 60°C for 12 hours to obtain a piperazine pyrophosphate coating.

[0094] Examples 2-21 and Comparative Examples 1-3 refer to Example 1, and the differences between them and Example 1 are shown in Tables 1 and 2.

[0095] Table 1

[0096]

[0097]

[0098] Table 2

[0099]

[0100]

[0101] Comparative Example 4

[0102] This comparative example provides a piperazine pyrophosphate coating, comprising a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core;

[0103] The coating layer includes dipalmitoyl tartaric acid diester and a coupling agent, wherein the coupling agent is isopropyl tris (dioctyl pyrophosphate acyloxy) titanate;

[0104] Based on 10 parts by weight of piperazine pyrophosphate, the weight of dipalmitoyl tartaric acid diester is 2.5 parts, and the weight of the coupling agent is 2.5 parts;

[0105] The average particle size of piperazine pyrophosphate was 20 μm.

[0106] The preparation method of the piperazine pyrophosphate coating of this comparative example comprises the following steps:

[0107] 10 parts by weight of piperazine pyrophosphate with an average particle size of 20 μm, 2.5 parts by weight of dipalmitoyl tartaric acid diester and 2.5 parts by weight of a coupling agent were added to 100 parts by volume of an ethanol / water solution, wherein the volume ratio of ethanol to water in the ethanol / water solution was 1:1. The mixture was stirred at 20°C and 800 rpm for 4 hours. The reaction product was centrifuged, and the precipitate obtained by centrifugation was washed three times with ethanol and then dried in a vacuum drying oven at 60°C for 12 hours to obtain a piperazine pyrophosphate coating.

[0108] Comparative Example 5

[0109] This comparative example provides a piperazine pyrophosphate coating, comprising a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core;

[0110] The coating layer includes dipalmitoyl tartaric acid diester and a coupling agent, wherein the coupling agent is isopropyl tris (dioctyl pyrophosphate acyloxy) titanate;

[0111] Based on 10 parts by weight of piperazine pyrophosphate, the weight of dipalmitoyl tartaric acid diester is 2.5 parts, and the weight of the coupling agent is 2.5 parts;

[0112] The average particle size of piperazine pyrophosphate was 20 μm.

[0113] The preparation method of the piperazine pyrophosphate coating of this comparative example comprises the following steps:

[0114] 10 parts by weight of piperazine pyrophosphate having an average particle size of 20 μm was added to 100 parts by volume of an ethanol / water solution, wherein the volume ratio of ethanol to water in the ethanol / water solution was 1:1, and stirred to obtain a first dispersion;

[0115] 2.5 parts by weight of dipalmitoyl tartaric acid diester was added to 50 parts by volume of ethanol, and the mixture was stirred at 50° C. and 800 rpm to dissolve. Then, 2.5 parts by weight of a coupling agent was added, and the mixture was stirred at 800 rpm for 35 minutes to obtain a second dispersion.

[0116] The second dispersion was added to the first dispersion, and ultrasonic dispersion was performed at an ultrasonic power of 200 W for 15 minutes to obtain a suspension. The suspension was stirred at a temperature of 25°C and a rotation speed of 800 rpm for 4 hours. The reaction product was centrifuged, and the precipitate obtained by centrifugation was washed three times with ethanol and then dried in a vacuum drying oven at 60°C for 12 hours to obtain a piperazine pyrophosphate coating.

[0117] Application Example 1

[0118] This application example provides a flame retardant composition, comprising the following components in parts by weight: 38.3 parts of copolymer PP K8009, 39 parts of homopolymer PP T30S, 22 parts of the piperazine pyrophosphate coating of Example 1, 0.3 parts of ethylene bisstearamide (EBS), 0.2 parts of antioxidant B215, and 0.2 parts of anti-dripping agent M532.

[0119] The method for preparing the flame retardant composition of this application example comprises the following steps:

[0120] The above components are mixed uniformly in proportion to obtain a premix;

[0121] The premix is added to a twin-screw extruder, mixed evenly, and melt-extruded to form granules to obtain the flame retardant composition; during the melt-extrusion granulation, the set temperatures of the twin-screw extruder from the feed port to the die are: zone 1 temperature 160°C, zone 2 temperature 180°C, zone 3 temperature 190°C, zone 4 temperature 190°C, zone 5 temperature 190°C, zone 6 temperature 190°C, and die head 200°C; the screw speed is 150 rpm, and the aspect ratio of the twin-screw extruder is 42.

[0122] Application Examples 2-21 and Comparative Application Examples 1-6

[0123] The components of the flame retardant compositions of Application Examples 2-21 and Comparative Examples 1-6 refer to those of Application Example 1, and the only difference between them and Application Example 1 is that: Application Examples 2-21 and Comparative Examples 1-6 use the piperazine pyrophosphate coatings of Examples 2-21 and Comparative Examples 1-6 to replace the piperazine pyrophosphate coating of Example 1, that is, Application Example 2 uses the piperazine pyrophosphate coating of Example 2 to replace the piperazine pyrophosphate coating of Example 1, and Application Example 3 uses the piperazine pyrophosphate coating of Example 3 to replace the piperazine pyrophosphate coating of Example 1, and so on; wherein Comparative Example 6 is piperazine pyrophosphate with an average particle size of 20 μm that has not been treated in any way;

[0124] The preparation methods of the flame retardant compositions of Application Examples 2-21 and Comparative Examples Application Examples 1-6 are the same as that of the flame retardant composition of Application Example 1.

[0125] Performance Testing

[0126] The piperazine phosphate coated materials obtained in the examples and comparative examples, and the flame retardant compositions obtained in the application examples and comparative examples were subjected to performance tests. The test methods are as follows:

[0127] (1) Water resistance: The solubility of the piperazine pyrophosphate coating in water was used to characterize the solubility of the piperazine pyrophosphate coating. 10 g of the piperazine pyrophosphate coating was stirred at 300 rpm for 20 min, then centrifuged at 2000 rpm for 20 min. The supernatant after centrifugation was filtered and the supernatant of V was pipetted from the filtrate using a pipette and placed in two beakers. The beakers containing the supernatant were placed in a 135°C oven for 2.5 h, then removed and placed in a desiccator to a constant weight. The mass of the beakers was measured using an analytical balance.

[0128] The water-soluble mass fraction W is expressed in grams per 100 milliliters (g / 100 mL) and is calculated according to the formula:

[0129] W=(m2-m1) / V×100;

[0130] m1--the value of the weight of a small beaker dried to a constant weight, in grams (g);

[0131] m2--The total weight of the filtrate in the dried beaker, in grams (g);

[0132] V--filtrate volume, in milliliters (mL).

[0133] (2) Izod impact strength: The flame retardant compositions of Application Examples 1-21 and Comparative Application Examples 1-6 were injection molded into specimens with a size of 80 mm × 10 mm × 4 mm and tested according to standard ASTM D256-24. The test conditions were: temperature of 25°C, notch depth of 2 mm, and impact energy of 2.75 J.

[0134] (3) Hydrophobic durability: Using a constant temperature and humidity test chamber set at 85°C and 85% humidity, the flame retardant compositions of Application Examples 1-21 and Comparative Application Examples 1-6 of equal mass were placed in the constant temperature and humidity test chamber, and the water absorption rate after 100 hours was tested;

[0135] (4) Thermal stability: 5-10 mg of piperazine pyrophosphate coating was measured and the temperature was raised from room temperature to 800°C at a heating rate of 20°C / min in an air atmosphere. The residual carbon rate at 800°C was calculated. The higher the residual carbon rate, the better the thermal stability.

[0136] The test results are shown in Table 3.

[0137] Table 3

[0138]

[0139]

[0140] From the experimental data in Table 3, it can be seen that the solubility of the piperazine pyrophosphate coating of the present application in water is ≤0.25 g / 100 mL, the residual carbon rate at 800°C is 24-41%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is ≥67 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.45%, indicating that the piperazine pyrophosphate coating of the present application has high water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0141] From the experimental data of Examples 1-5, it can be seen that when the molecular structure of the titanate coupling agent contains acyl pyrophosphate groups, the solubility of the obtained piperazine pyrophosphate coating in water is ≤0.11 g / 100 mL, the residual carbon rate at 800°C is 33.1-35.2%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is ≥105 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.17%. This indicates that when the molecular structure of the titanate coupling agent contains acyl pyrophosphate groups, the piperazine pyrophosphate coating has high water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0142] From the experimental data of Examples 6-7, it can be seen that when the molecular structure of the zirconate coupling agent contains a pyrophosphate acyloxy group, the solubility of the obtained pyrophosphate piperazine coating in water is 0.14 g / 100 mL, the residual carbon rate at 800°C is 30.5%, the cantilever beam impact strength of the flame retardant composition containing the pyrophosphate piperazine coating is 163 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is 0.26%. This indicates that when the molecular structure of the zirconate coupling agent contains a pyrophosphate acyloxy group, the pyrophosphate piperazine coating has high water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0143] From the experimental data of Examples 4 and 8-10, it can be seen that when the mass ratio of piperazine pyrophosphate to the coating layer is 1:(0.3-1), the solubility of the obtained piperazine pyrophosphate coating in water is ≤0.18 g / 100 mL, the residual carbon rate at 800°C is 28.5-38%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is ≥135 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.3%, indicating that when the mass ratio of piperazine pyrophosphate to the coating layer is 1:(0.3-1), the obtained piperazine pyrophosphate coating has higher water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0144] From the experimental data of Examples 9 and 11-13, it can be seen that when the mass ratio of dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.7-1), the solubility of the obtained piperazine pyrophosphate coating in water is ≤0.12 g / 100 mL, the residual carbon rate at 800°C is 35-38%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is ≥168 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.12%, indicating that when the mass ratio of dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.7-1), the obtained piperazine pyrophosphate coating has higher water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0145] From the experimental data of Examples 9 and 14-18, it can be seen that when the coupling agent is a titanate coupling agent and a zirconate coupling agent; and the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):1, the solubility of the obtained piperazine pyrophosphate coating in water is ≤0.09 g / 100 mL, the residual carbon rate at 800°C is 39-41%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is 165-175 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.11%; indicating that when the coupling agent is a titanate coupling agent and a zirconate coupling agent; and the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):1, the obtained piperazine pyrophosphate coating has higher water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0146] From the experimental data of Example 9 and Examples 19-21, it can be seen that when the average particle size of piperazine pyrophosphate is 20-40 μm, the solubility of the obtained piperazine pyrophosphate coating in water is ≤0.2 g / 100 mL, the residual carbon rate at 800°C is 27-38%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is 165-180 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≤0.29%; indicating that when the average particle size of piperazine pyrophosphate is 20-40 μm, the obtained piperazine pyrophosphate coating has higher water resistance, mechanical properties, hydrophobic durability and thermal stability.

[0147] From the experimental data of Example 9 and Comparative Examples 1-6, it can be seen that the coating layer is dipalmitoyl tartaric acid diester or a coupling agent, or other types of coupling agents are used, or the preparation method of the piperazine pyrophosphate coating is not within the scope of protection of this application, the solubility of the obtained piperazine pyrophosphate coating in water is ≥0.4 g / 100 mL, the residual carbon rate at 800°C is ≤28%, the cantilever beam impact strength of the flame retardant composition containing the piperazine pyrophosphate coating is ≤50 J / m, and the water absorption rate after being placed in an environment of 85% humidity and 85°C for 100 hours is ≥0.85%; it shows that only when dipalmitoyl tartaric acid diester and a specific type of coupling agent are compounded to form the coating layer, and the piperazine pyrophosphate coating is prepared using the preparation method of the present application, can a piperazine pyrophosphate coating with water resistance, mechanical properties, hydrophobic durability and thermal stability be obtained.

[0148] The coating layer contains only dipalmitoyl tartaric acid diester, which may lead to the decline in the overall performance of the pyrophosphate piperazine coating. The reasons are as follows: although the polar end of dipalmitoyl tartaric acid diester can bind to the surface of pyrophosphate piperazine through hydrogen bonds, the strength of the hydrogen bond is low and it is easy to break under high temperature or high humidity environment, causing the coating layer to fall off; and the single molecular layer lacks a cross-linking structure, and the unreacted or free dipalmitoyl tartaric acid diester monomers and pyrophosphate decomposition products are easy to migrate to the surface of the pyrophosphate piperazine coating, thereby causing the overall performance of the pyrophosphate piperazine coating to decline.

[0149] The coating layer contains only coupling agent, which may lead to the decline in the overall performance of the piperazine pyrophosphate coating. The reason is that the hydroxyl groups in the coupling agent react with the hydroxyl groups on the surface of piperazine pyrophosphate, thereby coating the surface of piperazine pyrophosphate. However, the number of hydroxyl groups on the surface of piperazine pyrophosphate is limited, and the exposed areas on the surface of piperazine pyrophosphate that are not chemically bonded by the coupling agent become water permeation channels, resulting in the decline in the overall performance of the piperazine pyrophosphate coating.

[0150] The use of other types of coupling agents in the coating layer may lead to a decrease in the overall performance of the piperazine pyrophosphate coating. The reasons may be: alkaline coupling agents (such as aminosilane) will destroy the hydrogen bonds of tartaric acid esters, and the long-chain alkyl groups in other types of coupling agents cover the surface of piperazine pyrophosphate, hindering the polar end anchoring of dipalmitoyl tartaric acid diester, causing the double coating layer to become a physical mixed layer; and the viscosity of dipalmitoyl tartaric acid diester (C16 chain) and the long-chain alkyl groups of the coupling agent increases at low temperatures, making it difficult to spread into a monomolecular layer on the surface of piperazine pyrophosphate, resulting in a decrease in the overall performance of the piperazine pyrophosphate coating.

[0151] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of the present disclosure rather than to limit the scope of protection of the present disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present disclosure may be modified or replaced by equivalents without departing from the essence and scope of the technical solutions of the present disclosure.

Claims

1. A piperazine pyrophosphate coated material, characterized in that: It comprises a piperazine pyrophosphate core and a coating layer coated on the surface of the piperazine pyrophosphate core; The coating layer comprises dipalmitoyl tartaric acid diester and a coupling agent, and the coupling agent is a titanate coupling agent and / or a zirconate coupling agent.

2. The piperazine pyrophosphate coated material according to claim 1, wherein The mass ratio of the piperazine pyrophosphate core to the coating layer is 1:(0.3-1); And / or, the mass ratio of the dipalmitoyl tartaric acid diester to the coupling agent is 1:(0.5-1.2).

3. The piperazine pyrophosphate coated material according to claim 1, wherein The coupling agent is a titanate coupling agent and a zirconate coupling agent; the mass ratio of the titanate coupling agent to the zirconate coupling agent is (2-8):

1.

4. The piperazine pyrophosphate coated material according to claim 1, wherein The titanate coupling agent includes monoalkoxy titanate and / or neoalkoxy titanate.

5. The piperazine pyrophosphate coated material according to claim 4, wherein The monoalkoxy titanate includes at least one of isopropoxy triisostearyl titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate acrylamide chelate, tetraoctyl bis(dilauryl phosphite acyloxy) titanate, triethanolamine chelate of bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropoxy tri(dodecylbenzenesulfonyloxy) titanate, tetraisopropyl di(dioctyl phosphite acyloxy) titanate, bis(dioctyl pyrophosphate acyloxy) ethylene titanate, isopropyl tri(branched and linear dioctyl phosphite acyloxy) titanate, isopropoxy dioleyl (dioctyl phosphite acyloxy) titanate, propoxy titanium tristearate, isopropoxy trioleyl titanate, and isopropoxy tri(ethylenediamino-N-ethoxy) titanate; And / or, the neoalkoxy titanate includes at least one of neoalkoxy tris (p-aminophenoxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate acrylamide chelate, neoalkoxy tris (diisooctyl phosphate) titanate, neoalkoxy tris (neodecanoyloxy) titanate, neoalkoxy tris (dioctyl pyrophosphate) titanate, and neoalkoxy tris (dioctyl phosphate) titanate.

6. The piperazine pyrophosphate coated material according to claim 1, wherein The zirconate coupling agent includes at least one of neoalkoxy tris (dioctyl phosphate) zirconate, neoalkoxy tris (dodecylbenzenesulfonyloxy) zirconate, neoalkoxy tris (neodecanoyloxy) zirconate, and neoalkoxy tris (dioctyl pyrophosphate) zirconate.

7. The piperazine pyrophosphate coated material according to claim 1, wherein The piperazine pyrophosphate core is formed of piperazine pyrophosphate, and the average particle size of the piperazine pyrophosphate is 10-50 μm.

8. A method for preparing the piperazine pyrophosphate coated material according to any one of claims 1 to 7, characterized in that: The following steps are involved: preparing a first dispersion containing piperazine pyrophosphate; preparing a second dispersion containing dipalmitoyl tartaric acid diester and a coupling agent; The second dispersion liquid is added to the first dispersion liquid, and ultrasonic dispersion is performed. The obtained suspension liquid is subjected to heating reaction, solid-liquid separation, and drying to obtain the piperazine pyrophosphate coated material.

9. The method for preparing the piperazine pyrophosphate coated material according to claim 8, wherein: The heating reaction temperature is 60-80h and the time is 3-6h; And / or, the ultrasonic dispersion has a power of 200-400 W and a time of 10-30 min.

10. A flame retardant composition, characterized in that The flame retardant composition includes the piperazine pyrophosphate coating as described in any one of claims 1 to 7 or the piperazine pyrophosphate coating prepared by the method for preparing the piperazine pyrophosphate coating as described in any one of claims 8 to 9.

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