CN103709431B - Polystyrene with high flame retardant property and preparation method thereof - Google Patents

Abstract

The invention discloses a method for preparing polystyrene with high flame-retardant performance and the prepared polystyrene material, using halogen-free environment-friendly solid flame retardant hypophosphite, phenylphosphinate and halogen-free liquid flame-retardant Agent compound flame retardant, acting on polystyrene materials. The preparation method of the polystyrene material is to put a dispersant, an emulsifier, an initiator, and styrene in a high-pressure polymerization kettle to react, and after reaching a certain conversion rate, add a compound flame retardant; when the particles harden, add Foaming agent; close the reaction kettle, heat up and keep it, wash and dry to obtain material beads; foam the obtained material beads, mature the foam balls at room temperature, and mold them to obtain high flame-retardant polystyrene materials. The invention adopts the compounding of halogen-free environment-friendly solid flame retardant and halogen-free liquid flame retardant, and the solid phase flame retardant is evenly dispersed in the liquid phase flame retardant to achieve the effect of synergistic flame retardancy, which solves the problem of polystyrene material flame retardancy. Combustibility issues, while maintaining the various superior properties of polystyrene.

Description

High flame retardant polystyrene and its preparation method

technical field

The present invention relates to a polystyrene material and its preparation method, in particular to a high flame retardant polystyrene and its preparation method, including high flame retardant expanded polystyrene (EPS) material and high flame retardant Extruded polystyrene (XPS) material.

Background technique

Polystyrene (PS) is a thermoplastic resin that is widely used because of its low price and easy processing. Expandable polystyrene (EPS) and extruded polystyrene (XPS) are widely used at present. Especially EPS material, due to its excellent performance, low cost, simple and feasible production molding process equipment and can be made into products with different requirements, it has developed rapidly. At present, my country has become the world's largest producer of EPS, and its total production and consumption rank first in the world. Due to the superior thermal insulation performance of polystyrene material, it is widely used in external wall thermal insulation materials, and its annual demand is still increasing rapidly, and the market potential is very huge.

But unfortunately, this polystyrene material is a polymer material mainly composed of C and H elements. In addition, it is a rigid foam with a closed-cell structure. After foaming, it presents a thin-walled porous state, so This makes it one of the materials with the lowest limiting oxygen index among all polymer materials. It is extremely flammable. It can not only be ignited at a lower temperature, but also burn violently once it is ignited. The flame spreads and spreads to the entire surface at a high speed, making the substrate High shrinkage and melting, no charcoal formation, and a large amount of black smoke, toxic gas and molten droplets with open flames at the same time, resulting in more serious combustion development.

Due to the special molecular chain structure, degradation and combustion characteristics of polystyrene materials and the characteristics of foam structure, it is quite difficult to modify their flame retardancy, especially the preparation of polystyrene foam materials with excellent flame retardancy and mechanical properties is still a long way to go. worldwide problem.

At present, there are not many researches and reports on polystyrene materials with high flame retardancy, and the flame retardants involved include halogen-based, phosphorus-based, nitrogen-phosphorus composites and inorganic flame retardants.

Chinese patent (CN11796114A) discloses the use of 10-60wt% of flame retardants and adhesives with a particle size of 1-50μm to coat the surface of expandable polystyrene beads and primary foamed particles, improving the Insulation and flame retardancy of expanded polystyrene foam, the flame retardant used is one or more of metal or non-metal oxides, metal or non-metal hydroxides, silicates, borates and carbonates kind. The flame retardant used in this method has poor compatibility with polystyrene foam particles, and the mechanical properties of the obtained polystyrene material are difficult to meet the requirements for use.

U.S. Yabao Company (CN101087819A) and Oohara (USPatent 6569912) both disclosed the use of brominated flame retardants or nitrogen-containing phosphorus flame retardants and HBCD compound flame retardants, both of which made polystyrene materials achieve a higher level. flame retardant properties. However, with the enhancement of environmental awareness and safety awareness, a series of safety and environmental issues brought about by halogen flame retardant systems will increasingly attract more attention.

Finding new and efficient flame retardants is the development trend of flame retardant modification of polystyrene materials.

Contents of the invention

The purpose of the present invention is to address the deficiencies in the prior art, to provide a method for preparing polystyrene with high flame-retardant performance and the obtained polystyrene material with high flame-retardant performance. The material not only has good flame-retardant performance, but also has good mechanical properties Also good.

For realizing the purpose of the present invention and solving its technical problems, adopt the following technical solutions:

A preparation method of high flame-retardant polystyrene, characterized in that said method comprises the following steps:

a) Add deionized water into the high-pressure polymerization reactor, put in dispersant, emulsifier and initiator and stir, put in styrene, heat up to 85-90°C and keep the kettle temperature constant to react;

b) When the reaction reaches a certain conversion rate, add a flame retardant; the flame retardant is a compound composed of hypophosphite, phenylphosphinate, dimethyl methylphosphonate and cyclic phosphonate flame retardant;

c) When the particles harden, add an appropriate amount of active calcium phosphate, and add foaming agent at the same time;

d) Close the reaction kettle, heat up to 105-125°C and keep it warm, cool down and discharge; wash and dry to obtain material beads;

e) Foaming the obtained material beads in a foaming machine; curing the pre-foamed balls at room temperature, and putting them into a mold to obtain the high flame-retardant polystyrene.

The flame retardant used in the present invention is a compound flame retardant of a halogen-free environment-friendly solid flame retardant hypophosphite, phenylphosphinate and a halogen-free liquid flame retardant. The hypophosphite is preferably aluminum hypophosphite, and the phenylphosphinate is preferably aluminum phenylphosphinate, aluminum methylphenylphosphinate, aluminum diethylphosphinate, aluminum hydroxymethylphenylphosphinate, Cyclic phosphonates such as bis(2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) methylphosphonate, Methylphosphonic acid (2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene)methyl ester, etc.

As for the compound flame retardant, the present invention recommends the use of compound flame retardants of aluminum hypophosphite, aluminum phenylphosphinate, dimethyl methyl phosphonate (DMMP) and cyclic phosphonate, and the mass ratios are respectively 1～2: 1～1.5: 1～2: 1～1.5.

The dosage of the compound flame retardant is 1.0-15wt% based on polystyrene material.

The dispersant in the aforementioned step a) can be activated calcium phosphate, hydroxyethyl cellulose, gelatin and the like. The present invention recommends using active calcium phosphate. The amount of dispersant used is 1.0-2.0% of the mass of polystyrene material.

The emulsifier in the aforementioned step a) can be nonionic emulsifier (such as Emcol PO-50, Aldo 28, Tegin, etc.) and anionic emulsifier (such as alkyl sulfonate, alkyl sulfate, etc.). The present invention recommends using sodium dodecylbenzenesulfonate. The amount of emulsifier used is 0.5-2% of the mass of polystyrene material.

The initiator in the aforementioned step a) may be dialkyl peroxide, ester peroxide, or diacyl peroxide. The present invention recommends the use of dibenzoyl peroxide or tert-butyl peroxybenzoate. The usage amount of the initiator is 0.5-2% of the mass of the polystyrene material.

The foaming agent in the aforementioned step c) can be a physical foaming agent (such as pentane, Freon11, Freon114, etc.) or a chemical foaming agent (calcium carbonate, etc.). The present invention recommends the use of pentane. The amount of blowing agent used is 5% of the mass of polystyrene material.

In the method, the present invention recommends adding the flame retardant when the conversion rate is greater than or equal to 85% in step b).

In the above method, in step d), the present invention recommends that the heat preservation temperature after the closed reaction kettle is 115°C.

In the above method, in step e), the present invention recommends that the pre-expanded bubble balls be matured at room temperature for 24 hours.

The invention also relates to the high flame-retardant polystyrene material prepared by the method.

The polystyrene material prepared by the prior art is greatly limited in practical application due to its poor flame retardancy. The flame retardant used in the present invention is an environmentally friendly flame retardant, which is a compound flame retardant of a halogen-free and environmentally friendly solid flame retardant hypophosphite, phenylphosphinate and a halogen-free liquid flame retardant, and passed The dispersant makes the solid phase flame retardant uniformly dispersed in the liquid phase flame retardant. The compound flame retardants recommended by the present invention are specifically: aluminum hypophosphite, aluminum phenylphosphinate, DMMP and cyclic phosphonate compound flame retardants. Among them, aluminum hypophosphite is an inorganic phosphorus-based flame retardant, which has a high phosphorus content (41.89%), and aluminum has a certain smoke-suppressing effect, which can significantly reduce smoke density; aluminum phenylphosphinate is an organic phosphinate Flame retardant, excellent dispersion in organic phase; DMMP and cyclic phosphonate are organophosphorus flame retardants, which can make poly Styrene material achieves Class A flame retardant properties.

The present invention adopts halogen-free environment-friendly solid flame retardant hypophosphite, phenyl phosphinate and halogen-free liquid flame retardant to compound and act on polystyrene materials, and the solid phase flame retardant is uniformly dispersed in the liquid phase flame retardant It achieves the effect of high efficiency and synergistic flame retardancy, and solves the problem of poor flame retardancy of polystyrene materials. The high flame-retardant polystyrene material prepared by the method of the present invention greatly improves its performance while maintaining various original excellent properties of polystyrene (such as: physical and mechanical properties, acid and alkali resistance, etc.). The flame retardancy meets the fire resistance requirements of polystyrene materials, and the preparation steps are simple, the process conditions are easy to control, the environment is friendly, the cost of raw materials is low, and it is more suitable for industrial production.

The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and implement it according to the description, the following are preferred embodiments of the present invention. The scope of the invention is not limited to the specific examples described, but is defined by the claims. Any other implementations of the same type formed by combinations and changes within the scope of the claims shall fall within the scope of the present invention without departing from the purpose and gist of the present invention.

Detailed ways

Example 1

According to the recipe, weigh 100g of deionized water into the autoclave, add 2g of activated calcium phosphate, 2g of sodium dodecylbenzenesulfonate, and 2g of dibenzoyl peroxide to stir, add 200g of styrene, and raise the temperature to keep the temperature of the kettle constant. React at 85°C; after reaching ≥85% conversion rate, add 7.5g of aluminum hypophosphite, 7.5g of aluminum phenylphosphinate, 7.5g of dimethyl methylphosphonate and 7.5g of bis(2- Methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) ester compound flame retardant; when the particles harden, add an appropriate amount Activated calcium phosphate, add 10g of pentane at the same time; close the reaction kettle, heat up to 115°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; foam the obtained material beads in a foamer Foaming; mature the pre-foamed balls at room temperature for 24 hours, and put them into the mold to obtain a high flame-retardant polystyrene material.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 32, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.6%, the bending strength is 0.3Mpa, the compressive strength is 0.15Mpa, and the thermal conductivity is 0.035w /m.k ^.

Example 2

According to the formula, take 100g of deionized water in the autoclave, add 2.5g of activated calcium phosphate, 2.5g of sodium dodecylbenzenesulfonate, and 2.5g of dibenzoyl peroxide to stir, add 200g of styrene, and heat up to make React at a constant temperature of 85°C; after reaching a conversion rate of ≥85%, add 7.5g of aluminum hypophosphite, 7.5g of aluminum phenylphosphinate, 7.5g of dimethyl methylphosphonate and 7.5g of methyl Phosphonic acid bis(2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) ester compound flame retardant; when the particle becomes After hardening, add an appropriate amount of active calcium phosphate, and add 10g of pentane at the same time; close the reaction kettle, heat up to 115°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; the obtained material beads Foam in a foamer; mature the pre-foamed balls at room temperature for 24 hours, and put them into the mold to obtain a high flame-retardant polystyrene material.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 33, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.5%, the bending strength is 0.3Mpa, the compressive strength is 0.17Mpa, and the thermal conductivity is 0.037w /m.k ^.

Example 3

According to the recipe, weigh 100g of deionized water in a high-pressure polymerization kettle, add 4g of activated calcium phosphate, 4g of sodium dodecylbenzenesulfonate, and 2.5g of tert-butyl peroxybenzoate to stir, add 200g of styrene, and heat up to make the kettle React at 90°C with constant temperature; after reaching ≥85% conversion rate, add 5g of aluminum hypophosphite, 5g of aluminum phenylphosphinate, 5g of dimethyl methylphosphonate and 5g of bis(2 -Methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) ester compound flame retardant; when the particles harden, add Appropriate amount of active calcium phosphate, and add 10g of pentane at the same time; close the reaction kettle, heat up to 115°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; put the obtained material beads in a foamer Foaming: Mature the pre-foamed balls at room temperature for 24 hours, and mold them to obtain polystyrene materials with high flame retardancy.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 33, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.5%, the bending strength is 0.3Mpa, the compressive strength is 0.17Mpa, and the thermal conductivity is 0.037w /m.k ^.

Example 4

According to the recipe, weigh 100g of deionized water in a high-pressure polymerization kettle, add 4g of activated calcium phosphate, 4g of sodium dodecylbenzenesulfonate, and 2.5g of tert-butyl peroxybenzoate to stir, add 200g of styrene, and heat up to make the kettle Temperature constant reaction at 85°C; after reaching ≥85% conversion rate, add 10g of aluminum hypophosphite, 7.5g of aluminum phenylphosphinate, 7.5g of dimethyl methylphosphonate and 5g of methylphosphonic acid ( 2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) methyl ester) compound flame retardant; when the particles harden , add an appropriate amount of active calcium phosphate, and add 10g of pentane at the same time; close the reaction kettle, heat up to 115°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; Foaming in a bubbler; curing the pre-foamed balls at room temperature for 24 hours, and then molded to obtain a high flame-retardant polystyrene material.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 32, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.5%, the bending strength is 0.3Mpa, the compressive strength is 0.15Mpa, and the thermal conductivity is 0.040w /m.k ^.

Example 5

According to the formula, weigh 100g of deionized water in the autoclave, add 3g of activated calcium phosphate, 2.5g of sodium dodecylbenzenesulfonate, and 3g of tert-butyl peroxybenzoate to stir, add 200g of styrene, and heat up the kettle to Temperature constant reaction at 87°C; after reaching ≥85% conversion rate, add 10g of aluminum hypophosphite, 7.5g of aluminum phenylphosphinate, 7.5g of dimethyl methylphosphonate and 5g of methylphosphonic acid ( 2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) methyl ester) compound flame retardant; when the particles harden , add an appropriate amount of active calcium phosphate, and add 10g of pentane at the same time; close the reaction kettle, heat up to 110°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; Foaming in a bubbler; curing the pre-foamed balls at room temperature for 24 hours, and then molded to obtain a high flame-retardant polystyrene material.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 32, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.3%, the bending strength is 0.3Mpa, the compressive strength is 0.17Mpa, and the thermal conductivity is 0.040w /m.k ^.

Example 6

According to the formula, weigh 100g of deionized water in a high-pressure polymerization kettle, add 3.5g of active calcium phosphate, 3.5g of sodium dodecylbenzenesulfonate, and 2.5g of tert-butyl peroxybenzoate to stir, add 200g of styrene, and heat up Keep the kettle temperature constant and react at 85°C; after reaching a conversion rate of ≥85%, add 7.5g of aluminum hypophosphite, 10g of aluminum phenylphosphinate, 7.55g of dimethyl methylphosphonate and 5g of methylphosphonic acid (2-Methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphorinyl-5-methylene) methyl ester) compound flame retardant; when the particles become hard Finally, add an appropriate amount of active calcium phosphate, and add 10g of pentane at the same time; close the reaction kettle, heat up to 110°C and keep it warm for a period of time, then cool down to 38°C and discharge; wash and dry to obtain material beads; Foaming in a foaming machine; curing the pre-foamed balls at room temperature for 24 hours, and then molded to obtain a high flame-retardant polystyrene material.

The flame retardancy and mechanical performance test results of the polystyrene material show that: the oxygen index is 33, the vertical combustion level is UL-94 V-0 level, the water absorption rate is 1.3%, the bending strength is 0.3Mpa, the compressive strength is 0.16Mpa, and the thermal conductivity is 0.039w /m.k ^.

Claims (7)

1. a preparation method for Polystyrene with high flame retardant property, is characterized in that, described method comprises the following steps:

A) deionized water is added in high pressure polymerisation reactor, drop into dispersion agent, emulsifying agent and initiator and stir, drop into vinylbenzene, be warming up to 85-90 DEG C and keep the constant lower reaction of still temperature;

B) after reaction reaches transformation efficiency >=85%, compound flame retardant is added; Described compound flame retardant is the compound flame retardant of hypo-aluminum orthophosphate, aluminum phenylphosphinate, dimethyl methyl phosphonate and annular phosphonate composition, and mass ratio is respectively 1 ~ 2:1 ~ 1.5:1 ~ 2:1 ~ 1.5; Described annular phosphonate is selected from methyl-phosphorous acid two (2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphepin cyclohexyl-5-methylene radical) ester, methyl-phosphorous acid (2-methyl-5-ethyl-2-oxo-1,3,2-dioxaphosphepin cyclohexyl-5-methylene radical) methyl ester;

C) after particle is hardening, add appropriate active calcium phosphate, add whipping agent simultaneously;

D) closed reactor, is warming up to 105-125 DEG C and is incubated, cooling discharge; Washing, drying, obtain material bead;

E) resulting materials bead is foamed in foam maker; By the at room temperature slaking of the alveolar sphere of pre-frothing, enter mould and namely obtain described Polystyrene with high flame retardant property.

2. the preparation method of Polystyrene with high flame retardant property according to claim 1, is characterized in that, the consumption of described compound flame retardant is the 1.0-15wt% of polystyrene material.

3. the preparation method of Polystyrene with high flame retardant property according to claim 1, is characterized in that, the dispersion agent described in step a) is active calcium phosphate, Natvosol or gelatin, and usage quantity is the 1.0-2.0% of polystyrene material quality.

4. the preparation method of Polystyrene with high flame retardant property according to claim 1, is characterized in that, the emulsifying agent described in step a) is nonionic emulsifier or anionic emulsifier, and usage quantity is the 0.5-2% of polystyrene material quality.

5. the preparation method of Polystyrene with high flame retardant property according to claim 1, is characterized in that, the initiator described in step a) is peroxidation two alkane, peroxyester or peroxidation two acyl, the 0.5-2% of usage quantity polystyrene material quality.

6. the preparation method of Polystyrene with high flame retardant property according to claim 1, is characterized in that, the whipping agent described in step c) uses pentane, and usage quantity is 5% of polystyrene material quality.

7. according to the polystyrene material that the preparation method of the arbitrary Polystyrene with high flame retardant property described in claim 1 to 6 obtains.