Flame-retardant expandable polystyrene and method for producing the same

Abstract

The application discloses a kind of flame-retardant expandable polystyrene and its preparation method.It includes the following raw materials: styrene, nucleating agent, desalted water, organic compound containing peroxide functional group, inorganic salt, bromine flame retardant, dispersant, solvent.The product powder and bulk material prepared by the application are less, and the prepared polystyrene board has excellent mechanical properties.After one week or even one month, no collapse, deformation and other phenomena occur, the combustion performance completely reaches B level, and has efficient flame-retardant fireproof performance.Meanwhile, the product obtained by the application has high bromine content, good thermal stability, low bleeding, no toxicity, little influence on material mechanical properties, and no toxic gas such as polybrominated dibenzo-p-dioxin and polybrominated dibenzofuran is produced during thermal cracking or combustion, which completely meets the requirements of European dioxin regulations and does not harm the environment.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of C08L25 / 04, and particularly relates to a flame-retardant expandable polystyrene and a preparation method thereof. BACKGROUND

[0002] In recent years, with the wide application of polystyrene materials in the market, the improvement of people's living standards and the progress of science and technology, higher requirements have been put forward for the related use performance of expandable polystyrene. Polystyrene materials with only single performance are difficult to meet people's various use requirements. Polystyrene materials have the disadvantages of low oxygen index, easy combustion, and molten material dripping with visible fire after combustion, and large smoke density. In order to fundamentally eliminate the hidden danger of igniting polystyrene materials, it is necessary to modify or treat polystyrene materials with flame retardation. At present, most of the flame-retardant polystyrene materials are obtained by adding a large amount of flame retardant, but the addition of a large amount of flame retardant will affect the mechanical properties of the materials, so that the obtained materials cannot meet the requirements of high flame retardation and high mechanical properties at the same time, affecting the further popularization and use of the materials. At the same time, after adding conventional bromine-based flame retardants to the current polystyrene materials, toxic gases such as polybrominated dibenzodioxin and polybrominated dibenzofuran are easily produced during the combustion process, which causes great harm to human health and the natural environment.

[0003] A kind of environment-friendly flame-retardant expandable polystyrene resin and its preparation method are disclosed in Chinese patent application No.CN202110020360.8, which uses environment-friendly flame retardant to solve the technical problem of resin having flame retardation, but the technical problem of expandable polystyrene resin having both flame retardation and excellent mechanical properties is not solved.

[0004] Therefore, it is the main technical problem to be solved at present to provide an expandable polystyrene having both flame retardation and excellent mechanical properties. SUMMARY

[0005] In order to solve the above technical problems, the first aspect of the present application provides a flame-retardant expandable polystyrene, comprising the following raw materials by weight: styrene 90-120 parts, nucleating agent 0.1-0.5 parts, desalted water 125-135 parts, organic compound containing peroxide functional group 0.2-0.5 parts, inorganic salt 0.16-0.78 parts, bromine-based flame retardant 0.5-4.5 parts, dispersant 0.001-0.003 parts, and solvent 6-8 parts; the viscosity of the nucleating agent at higher than 100℃ is 180-250 cps, and the acid value is 15-17 mg KOH / g, and the inorganic salt comprises phosphate and sulfate.

[0006] Preferably, the bromine-based flame retardant is selected from the group consisting of one or more of pentabromobenzyl acrylate (CAS No. 59447-55-1), 2,4,6-tribromophenyl allyl ether (CAS No. 3278-89-5), tribromophenyl allyl ether (CAS No. 3278-89-5), octabromoether (CAS No. 21850-44-2), decabromodiphenyl ether (CAS No. 1163-19-5), methyl octabromoether (CAS No. 97416-84-7), brominated SBS (CAS No. 1195978-93-8).

[0007] Further, the bromine-based flame retardant is methyl octabromoether.

[0008] Preferably, the nucleating agent is selected from the group consisting of one or more of polyethylene wax, polybutylene terephthalate, poly 3-methylbutene-1, polyvinylcyclosilane.

[0009] Further, the nucleating agent is polyethylene wax.

[0010] Preferably, the polyethylene wax has a viscosity of 180-250 cps at 140°C.

[0011] Further, the polyethylene wax has a viscosity of 210 cps at 140°C.

[0012] The cps, i.e. centipoise, is a unit of fluid viscosity, indicating the measure of internal friction of a liquid when it flows under a certain shear stress; the testing method thereof is not particularly limited in the present application, and various viscosity testing methods well known to those skilled in the art can be used, such as measurement using a Brookfield rotational viscometer.

[0013] Preferably, the polyethylene wax has an acid value of 15-17 mg KOH / g.

[0014] Further, the polyethylene wax has an acid value of 16 mg KOH / g.

[0015] The acid value refers to the milligrams of potassium hydroxide (KOH) needed to neutralize one gram of a chemical substance, and the unit is mg KOH / g; the testing method thereof is not particularly limited in the present application, and acid value testing methods well known to those skilled in the art can be used, such as ASTM D-1386.

[0016] The polyethylene wax is Honeywell polyethylene wax, with a model number of A-C655, a viscosity of 210 cps at 140°C, and an acid value of 16 mg KOH / g.

[0017] The inventors use methyl octabromo ether as a flame retardant to obtain corresponding flame retardant performance, which is difficult to penetrate the cell membrane of living organisms to participate in metabolism due to its high molecular weight, can well avoid the problem of biological accumulation, and greatly reduces its impact on the environment. The inventors found in experiments that although the flame retardant performance of the obtained flame-retardant expandable polystyrene is improved, the mechanical properties of the material decrease, and after long-term storage, the material is prone to collapse, deformation and other phenomena, and the flame retardant is prone to uneven distribution, resulting in unstable flame retardant performance. The inventors found in further research and development that when the viscosity of the polyethylene wax used is 180-250 cps and the acid value is 15-17 mg KOH / g at 140℃, the flame retardant performance and mechanical properties of the obtained material are further improved, and a foamed product with controllable foam cell size can be obtained. The inventors believe that, on the one hand, the polyethylene wax with a specific viscosity and acid value can coat the bromine-based flame retardant, especially methyl octabromo ether, and make methyl octabromo ether uniformly dispersed in the system, thereby improving the flame retardant performance of the obtained material and reducing the generation of toxic gases to some extent; the polyethylene wax coated with methyl octabromo ether can also undergo intermolecular crosslinking reaction with methyl octabromo ether, fill the internal voids of the styrene droplets, promote the styrene droplets to agglomerate into colloidal droplets with themselves as the core, and make the styrene droplets firmly coated on the surface of the bead material, thereby reducing the internal plasticizing effect of organic bromide on the polystyrene matrix and improving the mechanical properties of the obtained flame-retardant expandable polystyrene. On the other hand, further limiting the acid value of the polyethylene wax used to 15-17 mg KOH / g can prevent the activity of chain transfer and chain termination during the bulk polymerization of the styrene droplets from increasing after the addition of the bromine-based flame retardant to some extent, reduce the decomposition activation energy of organic compounds containing peroxide functional groups, effectively increase the relative molecular mass of the polystyrene, and improve the uniformity of the foam cell size of the expandable polystyrene during foaming, thereby improving the mechanical properties of the obtained flame-retardant expandable polystyrene.

[0018] Preferably, the conductivity of the desalinated water is less than 3 μs / cm.

[0019] Further, the conductivity of the desalinated water is 1 μs / cm.

[0020] The μs / cm is microsiemens per centimeter, which is the unit of conductivity.

[0021] Preferably, the peroxide functional group-containing organic compound is selected from the group consisting of one or more of benzoyl peroxide (CAS No. 94-36-0), t-butyl peroxybenzoate (CAS No. 614-45-9), t-amyl peroxy-2-ethylhexyl carbonate (CAS No. 70833-40-8), dicumyl peroxide (CAS No. 80-43-3), lauryl peroxide (CAS No. 105-74-8), di-t-butyl peroxide (CAS No. 110-05-4), cyclohexanone peroxide (CAS No. 12262-58-7), di-t-butyl peroxide dicyclohexyl carbonate (CAS No. 15520-11-3).

[0022] Further, the peroxide functional group-containing organic compound is selected from the group consisting of one or more of benzoyl peroxide, t-butyl peroxybenzoate, t-amyl peroxy-2-ethylhexyl carbonate, dicumyl peroxide.

[0023] Further, the peroxide functional group-containing organic compound is selected from the group consisting of one or more of benzoyl peroxide, t-butyl peroxybenzoate, t-amyl peroxy-2-ethylhexyl carbonate, dicumyl peroxide.

[0024] Preferably, the benzoyl peroxide, t-butyl peroxybenzoate, t-amyl peroxy-2-ethylhexyl carbonate, dicumyl peroxide are in a weight ratio of (5-8):(1-2):(1-2):(2-5).

[0025] Further, the benzoyl peroxide, t-butyl peroxybenzoate, t-amyl peroxy-2-ethylhexyl carbonate, dicumyl peroxide are in a weight ratio of 6.5:1.5:1.5:3.5.

[0026] Preferably, the inorganic salt comprises a phosphate salt and a sulfate salt.

[0027] Preferably, the phosphate salt-containing is selected from the group consisting of one or more of magnesium phosphate, calcium phosphate, sodium pyrophosphate, sodium hydrogen phosphate.

[0028] Further, the phosphate salt-containing comprises one or both of sodium pyrophosphate and calcium phosphate.

[0029] Further, the phosphate salt-containing is a combination of magnesium phosphate and calcium phosphate.

[0030] Further, the magnesium phosphate and calcium phosphate are in a weight ratio of 1:(2-5.7).

[0031] In a further preferred embodiment, the magnesium phosphate and calcium phosphate are in a weight ratio of 1:4.2.

[0032] The inventors have found that when a specific ratio of magnesium phosphate and calcium phosphate is added to the system, the mechanical properties of the resulting material are significantly improved, and the generation of toxic gases is further reduced. The inventors speculate that the possible reason is that the porous structure of magnesium phosphate and calcium phosphate improves the dispersibility and stability of the flame retardant in the system, and also provides more reaction points for other components such as flame retardants, and more physical bonding points for polyethylene wax, promoting the formation of a network structure inside the system, significantly improving the mechanical properties of the material. At the same time, the physical structure composed of magnesium phosphate and calcium phosphate can also play a certain barrier role, combined with the specific viscosity and acid value of the polyethylene wax coating the bromine-based flame retardant, greatly improving the flame retardant efficiency while further reducing the generation of toxic gases. However, the inventors have also found that the use of bromine-based flame retardants and additives such as calcium phosphate increases the number of powdery particles in the resulting material, and the resulting material still undergoes bubble collapse, deformation, and other phenomena after long-term storage.

[0033] Preferably, the sulfate salt is selected from the group consisting of sodium bisulfite, sodium bisulfate, barium sulfate, magnesium sulfate, and sodium sulfite.

[0034] Further, the sulfate salt is sodium bisulfite.

[0035] Preferably, the dispersant is a polyoxyethylene ether phosphate ester salt surfactant and an alkyl sulfonate surfactant.

[0036] Further, the weight ratio of the polyoxyethylene ether phosphate ester salt surfactant and the alkyl sulfonate surfactant is 1:(0.8-1.2).

[0037] Further, the weight ratio of the polyoxyethylene ether phosphate ester salt surfactant and the alkyl sulfonate surfactant is 1:1.

[0038] As examples of phosphate ester salt surfactants, include but are not limited to: nonylphenol polyoxyethylene ether-3 phosphate (CAS No. 51811-79-1), nonylphenol polyoxyethylene ether-10 phosphate (CAS No. 51609-41-7), oleyl alcohol polyoxyethylene ether phosphate (CAS No. 39464-69-2), potassium lauryl ether phosphate (CAS No. 58318-92-6).

[0039] Preferably, the polyoxyethylene ether phosphate ester salt surfactant is oleyl alcohol polyoxyethylene ether phosphate.

[0040] As examples of the alkylsulfonate surfactant, there are included, but not limited to, sodium hexadecylbenzenesulfonate, alkylsulfonate phenyl ester (CAS No. 91082-17-6), docusate sodium (CAS No. 577-11-7), sodium octanesulfonate (CAS No. 5324-84-5), sodium 1-decanesulfonate (CAS No. 13419-61-9), sodium 1-heptanesulfonate (CAS No. 22767-50-6), sodium pentanesulfonate (CAS No. 207605-40-1), sodium 1-hexanesulfonate (CAS No. 2832-45-3).

[0041] Preferably, the alkylsulfonate surfactant is sodium hexadecylbenzenesulfonate.

[0042] The inventors further limit the weight ratio of the polyoxyethylene ether phosphate salt surfactant and the alkylsulfonate surfactant to be 1:(0.8-1.2), and when specific polyoxyethylene ether phosphate salt surfactants and alkylsulfonate surfactants are used, the number of powdery particles in the obtained material is reduced, and the mechanical properties of the obtained material are further improved, and no collapse, deformation, etc. occurs after long-term storage. The inventors believe that a certain proportion of polyoxyethylene ether phosphate salt surfactants and alkylsulfonate surfactants aggregate in the styrene droplets to form micellar structures with long and short chains alternating, which promotes the formation of ordered phases in the system; when they collide with polyethylene wax-coated bromine-containing flame retardants, the long and short chain alternating structure promotes the adsorption of magnesium phosphate and calcium phosphate in the polyethylene wax and styrene droplets, and improves the regularity between the molecular chains, reduces the influence of bromine-containing flame retardants and calcium phosphate additives on the network structure of the polymerization, promotes the formation of normal size droplets in the system, the number of powdery particles in the obtained material is reduced, and the mechanical properties of the obtained material are further improved, and no collapse, deformation, etc. occurs after long-term storage.

[0043] Preferably, the solvent is pentane.

[0044] Preferably, the pentane is one or both of iso-pentane and n-pentane.

[0045] Further, the pentane is a mixture of iso-pentane and n-pentane.

[0046] Preferably, the weight ratio of the iso-pentane and n-pentane is 1:(2-3).

[0047] Further, the weight ratio of the iso-pentane and n-pentane is 1:2.3.

[0048] Preferably, the raw material further includes an auxiliary.

[0049] Preferably, the raw material further includes 0.2-1 parts by weight of an auxiliary.

[0050] Preferably, the raw material further comprises 0.6 parts by weight of an auxiliary agent.

[0051] Preferably, the auxiliary agent is selected from the group consisting of a combination of one or more of a lubricant, an antistatic agent, a reducing agent, a plasticizer, a film coating agent, an inorganic filler, a pH regulator, a synergistic flame retardant, and a plastic stabilizer.

[0052] Further, the auxiliary agent is a mixture of a lubricant and an antistatic agent.

[0053] Preferably, the weight ratio of the lubricant and the antistatic agent is (6-25):1.

[0054] Preferably, the weight ratio of the lubricant and the antistatic agent is 14:1.

[0055] The antistatic agent is not particularly limited in the present application, and various antistatic agents known in the art can be used, such as polyethylene glycol PEG-400.

[0056] Preferably, the lubricant is zinc stearate and glyceryl stearate (CAS No. 123-94-4).

[0057] Further, the weight ratio of the zinc stearate and the glyceryl stearate is (1-2.5):1.

[0058] Further, the weight ratio of the zinc stearate and the glyceryl stearate is 1.5:1.

[0059] The second aspect of the present application provides a preparation method of the flame-retardant expandable polystyrene, comprising the following steps:

[0060] Step one: add styrene, nucleating agent, organic compound containing peroxide functional group, and bromine-based flame retardant into a reaction kettle in parts by weight, stir at a speed of 50-70 r / min at 25°C for 20-40 min, then add desalted water, phosphate, and dispersant, stir for 20-40 min, then heat to 85-95°C, keep for 0.5-1.5 h, then add sulfate to obtain a suspension material;

[0061] Step two: continue to keep the suspension material obtained in step one for 5-6 h, then fill nitrogen into the reaction kettle and add a solvent, continue to heat to 110-130°C, keep for 2-2.5 h under a pressure of 0.8-0.9 MPa, then cool to 30-40°C, dehydrate, dry, and package to obtain the flame-retardant expandable polystyrene.

[0062] Preferably, the preparation method of the flame-retardant expandable polystyrene comprises the following steps:

[0063] Step one: according to weight parts, into the reaction kettle is added styrene, nucleating agent, organic compound containing peroxide functional group, bromine flame retardant, stirring at 25 DEG C under the speed of 50-70 r / min for 20-40 min, then add desalted water, phosphate, dispersing agent, stirring for 20-40 min, then heated to 85-95 DEG C, keep warm for 0.5-1.5 h, then add sulfate, get the suspension material;

[0064] Step two: the suspension material obtained in step one continues to keep warm for 5-6 h, then add stabilizer until the suspension material is stable, fill nitrogen into the reaction kettle, and add pentane, continue to heat to 110-130 DEG C, keep warm for 2-2.5 h under 0.8-0.9 MPa pressure, then cool to 30-40 DEG C, dehydrate, dry, package, then the flame retardant expandable polystyrene is obtained.

[0065] Further, the preparation method of the flame retardant expandable polystyrene comprises the following steps:

[0066] Step one: according to weight parts, into the reaction kettle is added styrene, nucleating agent, organic compound containing peroxide functional group, bromine flame retardant, stirring at 25 DEG C under the speed of 60 r / min for 30 min, then add desalted water, phosphate, dispersing agent, stirring for 30 min, then heated to 90 DEG C, keep warm for 1 h, then add sulfate, get the suspension material;

[0067] Step two: the suspension material obtained in step one continues to keep warm for 5.3 h, then add stabilizer until the suspension material is stable, fill nitrogen into the reaction kettle, and add pentane, continue to heat to 120 DEG C, keep warm for 2.2 h under 0.85 MPa pressure, then cool to 35 DEG C, dehydrate, dry, package, then the flame retardant expandable polystyrene is obtained.

[0068] In another preferred embodiment, the preparation method of the flame retardant expandable polystyrene comprises the following steps:

[0069] Step one: according to weight parts, into the reaction kettle is added styrene, nucleating agent, organic compound containing peroxide functional group, bromine flame retardant, stirring at 25 DEG C under the speed of 60 r / min for 30 min, then add desalted water, phosphate, dispersing agent, stirring for 30 min, then heated to 90 DEG C, keep warm for 1 h, then add sulfate, get the suspension material;

[0070] Step two: the suspension material obtained in step one continues to keep warm for 5.3 h, then add stabilizer until the suspension material is stable, fill nitrogen into the reaction kettle, and add pentane, continue to heat to 120 DEG C, keep warm for 2.2 h under 0.85 MPa pressure, then cool to 35 DEG C, dehydrate, dry, add auxiliary agent, stir for 10 min, then package, then the flame retardant expandable polystyrene is obtained.

[0071] In order to avoid the problem of collapse and deformation of the flame-retardant expandable polystyrene after foaming, the inventors found in experiments that when the temperature is raised to 110-130 DEG C, the pressure is 0.8-0.9 MPa, the temperature is kept for 2-2.5 h, and then cooled to 30-40 DEG C, the obtained flame-retardant expandable polystyrene does not have the problem of collapse and deformation in application, and when the temperature is too high and the temperature keeping time is too long, the problem of collapse and deformation occurs.

[0072] The stabilizer is not particularly limited, and various stabilizers known to those skilled in the art can be used, such as calcium phosphate. The stable state of the mixed suspension material means that the particles in the suspension material no longer sink.

[0073] The expandable polystyrene is used according to actual needs to prepare corresponding materials, such as polystyrene (EPS) foam insulation board.

[0074] The application is specifically described below by examples, and if no other description is provided, the raw materials used are commercially available.

[0075] Beneficial effects:

[0076] 1. The flame-retardant expandable polystyrene is prepared by using styrene, nucleating agent, inorganic salt, bromine-based flame retardant and other additives according to the technical scheme provided by the application.

[0077] 2. The flame-retardant expandable polystyrene prepared by the application has a particle size of 0.7-0.98 mm, and less powder and bulk material,

[0078] 3. The flame-retardant expandable polystyrene prepared by the application can obtain a foaming product with controllable foaming cell size in application.

[0079] 4. The polystyrene board prepared according to the preparation method of the application has excellent mechanical properties, and does not have the problems of collapse and deformation after one week or even one month, and the combustion performance completely reaches B level (critical heat radiation flux ≥8.0 kW / m 2 , flame tip height Fs ≤150 mm within 20 s), and has high efficient flame-retardant and fireproof performance.

[0080] 5. The flame-retardant expandable polystyrene is prepared by one-step suspension polymerization, avoiding the secondary processing problem of the flame-retardant polystyrene prepared by melt extrusion, optimizing the process operation, and uniformly dispersing the flame retardant in the polystyrene material, and stabilizing the flame-retardant effect.

[0081] 6. The product obtained by the present application has high bromine content, good thermal stability, low bleeding, no toxicity, little influence on the mechanical properties of the material, and no toxic gases such as polybrominated dibenzodioxin and polybrominated dibenzofuran generated during thermal cracking or combustion, fully meeting the requirements of the European dioxin regulation and causing no harm to the environment. BRIEF DESCRIPTION OF DRAWINGS

[0082] Figure 1 The polystyrene plate prepared in Example 1 was cut and then subjected to microscope photographing test.

[0083] Figure 2 The polystyrene plate prepared in Example 2 was cut and then subjected to microscope photographing test.

[0084] Figure 3 The polystyrene plate prepared in Example 3 was cut and then subjected to microscope photographing test.

[0085] Figure 4 The polystyrene plate prepared in Example 7 was cut and then subjected to microscope photographing test. DETAILED DESCRIPTION

[0086] Example 1

[0087] Example 1 of the present application provides a flame-retardant expandable polystyrene, which comprises the following raw materials by weight: styrene 105 parts, nucleating agent 0.3 parts, desalted water 120 parts, organic compound containing peroxide functional group 0.35 parts, phosphate 0.4 parts, sulfate 0.045 parts, bromine-based flame retardant 2.5 parts, dispersant 0.002 parts, and solvent 7 parts.

[0088] The bromine-based flame retardant is methyl octabromo ether.

[0089] The nucleating agent is polyethylene wax, the viscosity of which at 140℃ is 210 cps, the acid value is 16 mg KOH / g, and it is Honeywell polyethylene wax A-C655.

[0090] The conductivity of the desalted water is 1 μs / cm.

[0091] The organic compound containing peroxide functional group is a combination of benzoyl peroxide, tert-butyl peroxybenzoate, tert-amyl-2-ethylhexyl peroxide carbonate, and dicumyl peroxide, and the weight ratio of the four is 6.5:1.5:1.5:3.5.

[0092] The phosphate salt is magnesium phosphate and calcium phosphate, and the weight ratio of the two is 1:4.2. The sulfate salt is sodium bisulfite.

[0093] The dispersant is a mixture of oleyl polyoxyethylene ether phosphate and sodium cetylphenyl sulfonate, and the weight ratio of the two is 1:1.

[0094] The solvent is a mixture of isopentane and n-pentane, and the weight ratio of the two is 1:2.3.

[0095] The stabilizer is calcium phosphate.

[0096] The preparation method of the above-mentioned flame-retardant expandable polystyrene comprises the following steps:

[0097] Step one: according to weight parts, add styrene, nucleating agent, organic compound containing peroxide functional group, bromine-based flame retardant into the reaction kettle, stir at 60 r / min for 30 min at 25 DEG C, then add desalted water, phosphate, dispersant, stir for 30 min, then heat to 90 DEG C, keep for 1 h, then add sulfate to obtain suspension material;

[0098] Step two: continue to keep the suspension material obtained in step one for 5.3 h, then add stabilizer until the suspension material is stable, fill nitrogen into the reaction kettle, and add pentane, continue to heat to 120 DEG C, keep for 2.2 h under the pressure of 0.85 MPa, then cool to 35 DEG C, dehydrate, dry, and package to obtain the flame-retardant expandable polystyrene.

[0099] Example 2

[0100] Embodiment 2 of the present application provides a kind of flame-retardant expandable polystyrene, including the following weight parts of raw materials: styrene 90 parts, nucleating agent 0.1 part, desalted water 125 parts, organic compound containing peroxide functional group 0.2 part, phosphate 0.15 part, sulfate 0.01 part, bromine-based flame retardant 0.5 part, dispersant 0.001 part, pentane 8 parts.

[0101] The bromine-based flame retardant is methyl octabromo ether; the nucleating agent is polyethylene wax, the viscosity at 140 DEG C is 210 cps, the acid value is 16 mg KOH / g, and it is Honeywell polyethylene wax A-C655.

[0102] The conductivity of the desalted water is 1 mu s / cm.

[0103] The organic compound containing peroxide functional group is a combination of benzoyl peroxide, tert-butyl peroxybenzoate, tert-amyl-2-ethylhexyl peroxide carbonate, and dicumyl peroxide, and the weight ratio of the four is 5:1:1:2.

[0104] The phosphate-containing salt is magnesium phosphate and calcium phosphate, and the weight ratio of the two is 1:1.4.

[0105] The sulfate is sodium bisulfite.

[0106] The dispersant is a mixture of oleyl polyoxyethylene ether phosphate and sodium cetylphenyl sulfonate, and the weight ratio of the two is 1:1.

[0107] The pentane is a mixture of iso-pentane and n-pentane, and the weight ratio of the two is 1:2.

[0108] The stabilizer is calcium phosphate.

[0109] The preparation method of the above-mentioned flame-retardant expandable polystyrene comprises the following steps:

[0110] Step one: according to weight parts, adding styrene, nucleating agent, organic compound containing peroxide functional group, bromine-based flame retardant into the reaction kettle, stirring at 50 r / min for 20 min at 25 DEG C, then adding desalted water, phosphate, dispersant, stirring for 20 min, then heating to 85 DEG C, keeping for 0.5 h, then adding sulfate to obtain the suspension material;

[0111] Step two: continuing to keep the suspension material obtained in step one for 5 h, then adding stabilizer until the suspension material is stable, filling nitrogen into the reaction kettle, and adding pentane, continuing to heat to 110 DEG C, keeping for 2 h under the pressure of 0.8 MPa, then cooling to 30 DEG C, dehydrating, drying, and packaging to obtain the flame-retardant expandable polystyrene.

[0112] Example 3

[0113] Embodiment 3 of the present application provides a kind of flame-retardant expandable polystyrene, including the following weight parts of raw materials: styrene 120 parts, nucleating agent 0.5 parts, desalted water 135 parts, organic compound containing peroxide functional group 0.5 parts, phosphate 0.7 parts, sulfate 0.08 parts, bromine-based flame retardant 4.5 parts, dispersant 0.003 parts, pentane 6.

[0114] The bromine-based flame retardant is methyl octabromo ether; the nucleating agent is polyethylene wax, the viscosity at 140 DEG C is 210 cps, the acid value is 16 mg KOH / g, and it is Honeywell polyethylene wax A-C655.

[0115] The conductivity of the desalted water is 1 μs / cm.

[0116] The organic compound containing peroxide functional group is a combination of benzoyl peroxide, tert-butyl peroxybenzoate, tert-amyl-2-ethylhexyl peroxide carbonate, and dicumyl peroxide, and the weight ratio of the four is 8:2:2:5.

[0117] The phosphate-containing salt is magnesium phosphate and calcium phosphate, and the weight ratio of the two is 1:8. The sulfate is sodium bisulfite.

[0118] The dispersant is a mixture of oleyl polyoxyethylene ether phosphate and sodium hexadecyl benzene sulfonate, and the weight ratio of the two is 1:1.

[0119] The pentane is a mixture of iso-pentane and n-pentane, and the weight ratio of the two is 1:3.

[0120] The stabilizer is calcium phosphate.

[0121] The preparation method of the flame-retardant expandable polystyrene comprises the following steps:

[0122] Step one: according to weight parts, adding styrene, nucleating agent, organic compound containing peroxide functional group, bromine flame retardant into the reaction kettle, stirring at 70 r / min for 40 min at 25 DEG C, then adding desalted water, phosphate, dispersant, stirring for 40 min, then heating to 95 DEG C, adding sulfate after 1.5 h, and obtaining suspension material;

[0123] Step two: continuing to heat the suspension material obtained in step one for 6 h, then adding stabilizer until the suspension material is stable, filling nitrogen into the reaction kettle, and adding pentane, then continuing to heat to 130 DEG C, heating for 2.5 h under 0.9 MPa pressure, then cooling to 40 DEG C, and after dehydration, drying and packaging, the flame-retardant expandable polystyrene is obtained.

[0124] Example 4

[0125] Embodiment 4 of the present application provides a kind of flame-retardant expandable polystyrene, and its specific embodiment is same with embodiment 1, except that the viscosity of the polyethylene wax is 400 cps at 140 DEG C, the acid value is 17 mg KOH / g, and it is Honeywell polyethylene wax A-C 673A.

[0126] Example 5

[0127] Embodiment 5 of the present application provides a kind of flame-retardant expandable polystyrene, and its specific embodiment is same with embodiment 1, except that the weight ratio of oleyl polyoxyethylene ether phosphate and sodium hexadecyl benzene sulfonate in the dispersant is 1:1.5.

[0128] Example 6

[0129] Embodiment 6 of the present application provides a kind of flame-retardant expandable polystyrene, and its specific embodiment is same with embodiment 1, except that the weight ratio of magnesium phosphate and calcium phosphate in the phosphate-containing phosphate is 1:6.

[0130] Example 7

[0131] Embodiment 7 of the present application provides a kind of flame-retardant expandable polystyrene, and its specific embodiment is same with embodiment 1, except that the preparation method of flame-retardant expandable polystyrene in step two continues to keep warm 5.3 h after the suspension material obtained in step one, and then the stabilizer is added to the suspension material to stabilize, nitrogen is filled into the reaction kettle, and pentane is added, and then the temperature is continuously increased to 140 DEG C, and then the temperature is kept for 4 h under the pressure of 0.85 MPa, and then the temperature is cooled to 35 DEG C, and then the dehydration, drying and packaging are carried out, and then the flame-retardant expandable polystyrene is obtained.

[0132] Example 8

[0133] Embodiment 8 of the present application provides a kind of flame-retardant expandable polystyrene, which comprises the following raw materials by weight: styrene 105 parts, nucleating agent 0.3 parts, desalted water 120 parts, organic compound containing peroxide functional group 0.35 parts, phosphate 0.4 parts, sulfate 0.045 parts, bromine-based flame retardant 2.5 parts, dispersant 0.002 parts, pentane 7 parts, and 0.6 parts of auxiliary.

[0134] The bromine-based flame retardant is methyl octabromo ether; the nucleating agent is polyethylene wax, the viscosity at 140 DEG C is 210 cps, the acid value is 16 mg KOH / g, and it is Honeywell polyethylene wax A-C655.

[0135] The conductivity of the desalted water is 1 μs / cm. The organic compound containing peroxide functional group is a combination of benzoyl peroxide, tert-butyl peroxybenzoate, tert-amyl-2-ethylhexyl peroxide carbonate, and dicumyl peroxide, and the weight ratio of the four is 6.5:1.5:1.5:3.5.

[0136] The phosphate containing phosphate is magnesium phosphate and calcium phosphate, and the weight ratio of the two is 1:4.2.

[0137] The sulfate is sodium bisulfite; the dispersant is a mixture of oleyl polyoxyethylene ether phosphate and sodium hexadecylbenzenesulfonate, and the weight ratio of the two is 1:1.

[0138] The pentane is a mixture of isopentane and n-pentane, and the weight ratio of the two is 1:2.3.

[0139] The auxiliary is a lubricant and an antistatic agent, and the weight ratio of the two is 14:1; the lubricant is zinc stearate and monoglyceride, and the weight ratio of the two is 1.5:1.

[0140] The stabilizer is calcium phosphate.

[0141] The above-mentioned preparation method of flame-retardant expandable polystyrene comprises the following steps:

[0142] Step one: according to weight parts, into the reaction kettle styrene, nucleating agent, organic compound containing peroxide functional group, bromine flame retardant, stirring at 60r / min speed for 30 min at 25℃, after adding desalted water, phosphate, dispersing agent, auxiliary, stirring for 30 min, heating to 90℃, after 1h adding sulfate, get the suspension material;

[0143] Step two: the suspension material obtained in step one continues to keep warm for 5.3h, add stabilizer to the suspension material, fill nitrogen into the reaction kettle, and add pentane, continue to heat to 120℃, keep warm for 2.2h under 0.85MPa pressure, then cool to 35℃, after dehydration, drying, packaging, the flame retardant expandable polystyrene is obtained.

[0144] Performance Evaluation

[0145] 1. Mechanical property test: the flame retardant expandable polystyrene obtained in examples 1-8 is prepared into polystyrene plate sample by the method known to those skilled in the art, and the dumbbell-shaped sample is prepared according to GB9641-1988 "hard foam tensile property test method", and the tensile property test is carried out at 25℃ using the testing machine, and the results are shown in table 1.

[0146] 2. Long-term stability test: the flame retardant expandable polystyrene obtained in examples 1-8 is prepared into polystyrene plate sample by the method known to those skilled in the art, and the sample is placed in a cool and ventilated place, and the sample is observed whether there is bubble collapse, deformation and other phenomena after one week and one month respectively, and the results are shown in table 1.

[0147] 3. Cell size test: the flame retardant expandable polystyrene obtained in examples 1, 2, 3 and 7 is prepared into polystyrene plate sample by the method known to those skilled in the art, and the polystyrene plate is cut and tested by microscope, and the test figure is shown in Figures 1-4 .

[0148] 4. Bead material content test: the flame retardant expandable polystyrene obtained in examples 1-8 is mixed uniformly, and 10 samples are randomly selected from each sample until the sample just covers the bottom of the entire culture dish (size 60mm), and the content of bead material with size of 0.5-0.98mm in the sample is evaluated. If the content of bead material is ≥90%, it is marked as O; if the content of bead material is <90%, it is marked as X.

[0149] 5. Flame retardant performance: the flame retardant expandable polystyrene obtained in Examples 1-8 was prepared into polystyrene board samples with a size of 1050 mm long x 230 mm wide x 60 mm thick according to GB / T 11785-2005 "Combustion behavior of floor coverings - radiant heat source method" after which the radiant flux at the point of flame extinguishment (CHF) or the radiant flux at the farthest position reached by the flame after 30 minutes of testing (HF-30) were obtained, and the lowest value of the two was selected as the critical heat radiation flux. At the same time, the flame retardant expandable polystyrene obtained in Examples 1-17 was prepared into polystyrene board samples with a size of 250 mm long x 90 mm wide x 60 mm thick according to GB / T 8626 "Test methods for combustibility of building materials" after which the flame tip height Fs at 20 s was tested at an air flow rate of 0.7 m / s using a surface ignition method in a combustion chamber.

[0150] According to the above test data, the samples were classified according to GB8624-2012 "Classification of the combustion behavior of building materials and products". Among them, B level is critical heat radiation flux ≥ 8.0 kW / m 2 , flame tip height Fs within 20 s ≤ 150 mm; C level is critical heat radiation flux ≥ 4.5 kW / m 2 , flame tip height Fs within 20 s ≤ 150 mm; D level is critical heat radiation flux ≥ 3.0 kW / m 2 , flame tip height Fs within 20 s ≤ 150 mm; E level is critical heat radiation flux ≥ 2.2 kW / m 2 , flame tip height Fs within 20 s ≤ 150 mm; if the above requirements are not met, it is recorded as F, and the results are shown in Table 1.

[0151] Table 1

[0152]

[0153] From the above experimental results, it can be seen that the flame-retardant expandable polystyrene is prepared by using styrene, nucleating agent, phosphate, bromine-based flame retardant and other auxiliaries. The product prepared by the application has excellent mechanical properties, and the tensile strength can reach 0.2 MPa. The content of the bead material is ≥90%, and the size of the bead material is 0.5-0.98 mm. The long-term stability test shows that there is no collapse or deformation after one week or even one month. The flame-retardant performance test shows that the combustion performance completely meets the B level, and has high efficient flame-retardant performance. In addition, the one-step suspension polymerization method is used to prepare the flame-retardant expandable polystyrene, which avoids the secondary processing problem of the flame-retardant polystyrene prepared by the melt extrusion method, optimizes the process operation, and makes the flame retardant evenly dispersed in the polystyrene material, and the flame-retardant effect is stable.

[0154] By Figures 1-3 It can be seen that the flame-retardant expandable polystyrene prepared by the raw materials and the preparation method defined in the application has full foaming cells, uniform foaming cell size, and does not have the problems of collapse and deformation. By Figure 4 It can be seen that when the preparation method is changed, the problems of collapse and deformation will occur.

[0155] The foregoing examples are illustrative only and are not intended to limit the scope of the application described herein. The appended claims are intended to claim as broad a range as is allowed under the rules of patent law. The examples presented herein are representative of the selection of embodiments of the application and are not intended to limit the scope of the application. Those skilled in the art will readily recognize a variety of non-essential changes and substitutions that can be made to the methods described herein without departing from the scope of the application.

Claims

1. A flame-retardant expandable polystyrene, characterized in that, It is composed of the following raw materials in parts by weight: 90-120 parts styrene, 0.1-0.5 parts nucleating agent, 125-135 parts deionized water, 0.2-0.5 parts organic compound containing peroxy functional group, 0.16-0.78 parts inorganic salt, 0.5-4.5 parts brominated flame retardant, 0.001-0.003 parts dispersant, and 6-8 parts solvent; wherein the inorganic salt includes phosphate and sulfate. The nucleating agent is polyethylene wax; The polyethylene wax has a viscosity of 180~250cps at 140℃ and an acid value of 15~17mg KOH / g. The dispersant is a polyoxyethylene ether phosphate salt surfactant and an alkyl sulfonate surfactant; The weight ratio of the polyoxyethylene ether phosphate surfactant to the alkyl sulfonate surfactant is 1:(0.8-1.2); The phosphate-containing salt is a combination of magnesium phosphate and calcium phosphate; The weight ratio of magnesium phosphate to calcium phosphate is 1:(2~5.7). The organic compound containing the peroxy functional group is selected from one or more combinations of benzoyl peroxide, tert-butyl peroxide, tert-amyl-2-ethylhexyl carbonate peroxide, dicumyl peroxide, lauroyl peroxide, di-tert-butyl peroxide, cyclohexanone peroxide, and di-tert-butylcyclohexyl peroxide.

2. The flame-retardant expandable polystyrene according to claim 1, characterized in that, The brominated flame retardant is selected from one or more combinations of pentabromobenzyl acrylate, 2,4,6-tribromophenylallyl ether, tribromophenylallyl ether, octabromoether, decabromodiphenyl ether, methyl octabromoether, and brominated SBS.

3. The flame-retardant expandable polystyrene according to any one of claims 1 to 2, characterized in that, The raw materials also include additives.

4. A method for preparing flame-retardant expandable polystyrene according to any one of claims 1 to 3, characterized in that, Includes the following steps: Step 1: According to the weight proportions, add styrene, nucleating agent, organic compound containing peroxy functional group, and brominated flame retardant to the reactor. Stir at 50~70 r / min for 20~40 min at 25℃. Then add demineralized water, phosphate, and dispersant. Stir for 20~40 min. Then raise the temperature to 85~95℃ and keep it at that temperature for 0.5~1.5 h. Then add sulfate to obtain the suspended material. Step 2: After keeping the suspended material obtained in Step 1 at a constant temperature for 5-6 hours, nitrogen gas is introduced into the reactor, and solvent is added. The temperature is then raised to 110-130℃ and kept at a pressure of 0.8-0.9MPa for 2-2.5 hours. After cooling to 30-40℃, the material is dehydrated, dried, and packaged to obtain flame-retardant expandable polystyrene.

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