CN110181636B

CN110181636B - Silicon-boron-nitrogen ternary flame retardant for natural plant fiber material and preparation method thereof

Info

Publication number: CN110181636B
Application number: CN201910503808.4A
Authority: CN
Inventors: 高中海; 吴子良; 左艳仙; 李菊珍; 赵志珩
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-06-12
Filing date: 2019-06-12
Publication date: 2020-10-02
Anticipated expiration: 2039-06-12
Also published as: CN110181636A

Abstract

The invention discloses a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials and a preparation method thereof, wherein each 1L of the flame retardant is prepared from the following raw materials: 45-70 g of sodium methyl silicate or sodium ethyl silicate, 21-35 g of boric acid, and 70-E of zinc nitrate or zinc nitrate solution120g, 5.0-11.0 g of sulfuric acid solution, 20-35 g of urea and the balance of water. When the flame retardant is prepared, water accounting for 50% of the total volume of the flame retardant to be prepared is injected into a reactor, sodium methyl silicate or sodium ethyl silicate and boric acid are added while stirring, the temperature is raised to 85 +/-5 ℃, the temperature is kept for 45-60 min, then zinc sulfate solution or zinc nitrate solution is added, urea is added, the temperature is kept for 20min at 85 +/-5 ℃, sulfuric acid solution is added to adjust the pH value to be 8.8-9.7, the temperature is lowered to 45 ℃, and finally water is added to the total volume of the flame retardant. The flame retardant disclosed by the invention is good in flame retardant effect, free of halogen, low in smoke generation rate and generation amount during combustion of the flame retardant material and up to standard in smoke toxicity, and the natural plant fiber flame retardant material or artificial board prepared from the flame retardant has combustion performance reaching B required by GB8624-2012₁(B) Stage or B₁(C) And (4) stages.

Description

Silicon-boron-nitrogen ternary flame retardant for natural plant fiber material and preparation method thereof

Technical Field

The invention relates to the technical field of flame retardant materials, in particular to a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials, and a preparation method and a use method thereof.

Background

The organic silicon fire retardant is a halogen-free fire retardant, a char-forming smoke suppressant and a good dispersant, and can increase the compatibility among materials. As a class of high-molecular flame retardant, the flame retardant has the characteristics of high efficiency, no toxicity, low smoke, no dripping, no pollution and the like. Silicon and boron elements are introduced into the same molecular structure to synthesize the organic borosilicate flame retardant, so that the price of the silicon flame retardant can be reduced, and the hydrolysis resistance stability of the boron flame retardant can be improved.

Some technologies can be used for preparing flame-retardant materials, for example, as disclosed in chinese patent application No. CN201810394399, "a flame-retardant environment-friendly cable material and a preparation method thereof", which proposes a method for preparing a flame-retardant cable material from a borosilicate block copolymer modified unsaturated polyester resin: the borosilicate resin is prepared by dissolving polymerized 2-amino benzenethiol grafted unsaturated polyester resin, 1, 4-butanediol divinyl ether, 2,4, 6-trivinyl boroxine, bis-trimethylsilyl vinyl phosphate, an initiator and an emulsifier in N-methyl pyrrolidone, stirring and reacting for 2-3 hours at 55-65 ℃ in a nitrogen atmosphere, precipitating in water, and granulating and drying. For example, in the patent document "a high temperature resistant flame retardant polyborosiloxane material and a preparation method thereof" disclosed in chinese patent application No. 201711349409, the patent document proposes to prepare a borosilicate flame retardant material: prepared by condensation of polyborosiloxane oligomer, polysiloxane oligomer with main chain containing naphthalene structure and polysiloxane oligomer in solvent. For example, a method for preparing a nano flame retardant disclosed in chinese patent application No. CN201810122139 proposes a method for synthesizing a phosphorus, boron and silicon nano flame retardant: firstly, mixing boric acid with hydroxyl-terminated silicone oil and micromolecular siloxane according to a proportion, and heating to dissolve the boric acid. And then, the small molecular substances are loaded into the cavity of the modified halloysite nanotube by grinding and negative pressure to obtain the halloysite nanotube loaded with the small molecular substances. Then reacting and crosslinking under the catalysis of concentrated sulfuric acid to generate the halloysite nanotube loaded with the polyboronate. And finally, reacting phosphorus oxychloride with the product under a certain condition to obtain the halloysite nanotube loaded with the phosphorus-boron-siloxane, namely the nano flame retardant.

However, the preparation method has the problems that an organic solvent with high toxicity is used in the preparation process, or the preparation process is complicated, the raw material cost is high, and the like.

Disclosure of Invention

The invention aims to solve the technical problem of providing a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials and a preparation method thereof, wherein the flame retardant has good flame retardant effect and no halogen, the smoke generation rate and the smoke generation amount are small when the flame retardant material is combusted, and the smoke toxicity reaches the standard.

The invention solves the technical problems by the following technical scheme:

the invention relates to a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials, wherein each 1L of the flame retardant is prepared from the following raw materials: 45-70 g of sodium methyl silicate or sodium ethyl silicate, 21-35 g of boric acid, 70-120 g of a zinc sulfate solution or a zinc nitrate solution with the mass concentration of 20%, 5.0-11.0 g of a sulfuric acid solution with the volume concentration of 20%, 20-35 g of urea and the balance of water.

The invention relates to a preparation method of a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials, which adopts the following operation steps:

firstly, water which is 50 percent of the total volume of the flame retardant to be prepared is injected into a reactor, sodium methyl silicate or sodium ethyl silicate and boric acid are added while stirring, the temperature is raised to 85 +/-5 ℃, the temperature is kept for 45-60 min, then zinc sulfate solution or zinc nitrate solution is added, stirring is carried out until the appeared precipitate is dissolved transparently, then urea is added, the stirring and the dissolution are completed, the temperature is kept for 20min at 85 +/-5 ℃, then sulfuric acid solution is added, the pH value is adjusted to 8.8-9.7, the temperature is reduced to 45 ℃, and finally water is added to the total volume of the flame retardant.

The invention relates to a using method of a silicon-boron-nitrogen ternary flame retardant for a natural plant fiber material, which comprises the following steps:

uniformly injecting a flame retardant into a natural plant fiber material or an artificial board by adopting an impregnation method or a spraying stirring method, wherein the solid drug-loading rate is 5.5-10.8%, then spreading or alternately stacking the materials, ventilating and aging for more than 72 hours, and drying the materials until the water content reaches the use requirement, wherein the prepared natural plant fiber flame-retardant material or artificial board has the combustion performance reaching the B requirement of GB8624-2012₁(B) Stage or B₁(C) And (4) stages.

The flame retardant of the present invention comprises an organosilicon-boron polymer formed by the reaction of sodium organosilicate and boric acid:

R：-CH₃or-CH₂-CH₃，n＝720～1500

The flame retardant disclosed by the invention has the following beneficial effects:

1) when the flame retardant is used, after the flame retardant is soaked into a natural plant fiber material, in the aging and drying processes, the organic silicon-boron polymer and the excessive organic sodium silicate generate dendritic, chain and net-shaped molecules through the interaction of active groups to form a net-shaped hydrophobic siloxane film, so that the flame retardant has higher leaching resistance.

2) The flame retardant does not contain chlorine, bromine halogen and phosphorus, but urea is added to form the silicon-boron-nitrogen ternary synergistic flame retardant, and the prepared flame retardant material has low smoke generation rate, smoke generation total amount and smoke toxicity during combustion.

3) The raw materials adopted by the flame retardant can be used as nutrients of crops (sulfuric acid exists in a form of sulfate and can be regarded as a sulfur fertilizer), and the flame retardant is nontoxic and safe to use and does not pollute the environment.

Detailed Description

Example 1 Synthesis of flame retardant of the invention having a Total volume of 1m³：

Take 0.5m³Adding water into a reactor, adding 45kg of sodium methylsilicate and 28kg of boric acid while stirring, heating to 85 ℃, keeping the temperature for 60min, adding 70kg of 20% (w/w) zinc sulfate solution, stirring until the precipitate is dissolved transparently, adding 20kg of urea, stirring completely, keeping the temperature at 85 ℃ for 20min, adding 5.1kg of sulfuric acid solution with the volume concentration of 20%, stirring uniformly, measuring the pH value to be 9.3 by using a precise pH test paper, cooling to 45 ℃, and finally adding water until the total volume of the flame retardant is 1m³And discharging to obtain the flame retardant A.

Comparative example 1

0.5m of common phosphorus-nitrogen-boron ternary flame retardant is prepared³: take 0.25m³Injecting water into a reactor, adding 40kg of ammonium polyphosphate with the polymerization degree of 30 +/-4, 5kg of borax and 5kg of boric acid, stirring until the ammonium polyphosphate, the borax and the boric acid are completely dissolved, discharging, and supplementing water until the total volume of the flame retardant is 0.5m³To obtain the flame retardant A'.

Example 2 Synthesis of a flame retardant according to the invention 0.5m³：

Take 0.25m³Injecting water into a reactor, adding 35kg of ethyl sodium silicate and 10.5kg of boric acid while stirring, heating to 90 ℃, keeping the temperature for 50min, adding 60kg of 20% (w/w) zinc sulfate solution, stirring until the precipitate is dissolved transparently, adding 17.5kg of urea, stirring completely, keeping the temperature at 90 ℃ for 20min, adding 5.1kg of sulfuric acid solution with the volume concentration of 20%, stirring uniformly, measuring the pH value to be 9.3 by using a precise pH test paper, cooling to 45 ℃, and finally adding water until the total volume of the flame retardant is 0.5m³And discharging to obtain the flame retardant B.

Example 3 Synthesis of flame retardant 1m according to the invention³：

Take 0.5m³Water is injected into a reactor, 60kg of sodium methylsilicate and 35kg of boric acid are added while stirring, and the temperature is raised toKeeping the temperature at 80 ℃ for 45min, adding 103kg of 20% (w/w) zinc nitrate solution, stirring until the precipitate is dissolved and transparent, adding 30kg of urea, stirring and dissolving completely, keeping the temperature at 80 ℃ for 20min, adding 7.8kg of sulfuric acid solution with the volume concentration of 20%, stirring uniformly, measuring the pH value to be 9.7 by using a precise pH test paper, cooling to 45 ℃, and adding water until the total volume of the flame retardant is 1m³And discharging to obtain the flame retardant C.

Example 4

Preparing a flame-retardant plywood:

firstly, carrying out flame-retardant treatment on veneers for plywood: soaking poplar veneer 1.8mm thick in the fire retardant A solution of example 1 at normal pressure, taking out after 8hr, vertically stacking at intervals, ventilating and aging in shade for over 72hr, and naturally drying in open air until the water content is about 15%. Measuring the solid drug-loading rate of 9.7% by single board, making 9 layers of 15mm thick urea-formaldehyde plywood on plywood production line by conventional method, E₁The glue has the glue application amount of 1.1 +/-0.1 kg/layer (4 × 8 feet double-sided), and the flame-retardant plywood is detected according to GB8624-2012 'rating of combustion performance of building materials and products', and the rating of combustion performance is B₁Stage (B-s2, d0, t 1). The results are as follows:

1) index of combustion growth rate FIGRA_0.2MJ：95(≤120)W/s

2) Flame lateral spread length LFS: meets the standard requirements (< sample edge)

3) Total heat release THR within 600s_600s：4.0(≤7.5)MJ

4) Tip height Fs within 60 s: surface flame bombardment of 50 (less than or equal to 150) mm and edge flame bombardment of 63 (less than or equal to 150) mm

5) Combustion drippings within 60 s: meets the standard requirement (no combustion drippage igniting filter paper phenomenon)

6) Smoke generation rate index SMOGRA: 23 (less than or equal to 180) m²/s²

7) Total smoke yield TSP within 600s_600s：117(≤200)m²

8) Burning drops/particles: meets the standard requirements (no burning drippings/particles within 600 s)

9) Flue gas toxicity rating: t1 (reaching quasi-safety level ZA)₃)

(the performance parameter in brackets is the requirement index of GB8624-2012 standard, the same below.)

The GB8624-2012 test result shows that the smoke generation rate, the smoke generation total amount and the smoke toxicity of the flame retardant disclosed by the invention in the experiment are low, and particularly the smoke toxicity reaches ZA₃And the flame retardant marking meets the requirement of obtaining the flame retardant marking in GB 20286-2006 flame retardant product and component combustion performance requirement and marking in public places.

Comparative example 2

A flame-retardant plywood was prepared using the solution of flame retardant a' of comparative example 1, in comparison with example 4:

firstly, carrying out flame-retardant treatment on veneers for plywood: soaking poplar veneer of 1.8mm thickness in the fire retardant solution of comparative example 1 at normal pressure, fishing out after 9.5hr, vertically stacking at intervals, ventilating and aging in shade for over 72hr, and naturally drying in the open air until the water content is about 15%. Measuring the single board to obtain a solid drug-loading rate of 10.6%, manufacturing 9 layers of urea-formaldehyde plywood with the thickness of 15mm on a plywood production line according to a conventional method, and E₁The glue has the glue application amount of 1.1 +/-0.1 kg/layer (4 × 8 feet double-sided), the flame-retardant plywood is detected according to GB8624-2012, and the burning performance is graded as B₁(B-s2, d0, t2) grade, and the smoke toxicity is unqualified. The results are as follows:

1) index of combustion growth rate FIGRA_0.2MJ：87.4(≤120)W/s

3) Total heat release THR within 600s_600s：4.8(≤7.5)MJ

4) Tip height Fs within 60 s: surface flame bombardment of 35 (less than or equal to 150) mm and edge flame bombardment of 33 (less than or equal to 150) mm

6) Smoke generation rate index SMOGRA: 62 (less than or equal to 180) m²/s²

7) Total smoke yield TSP within 600s_600s：187(≤200)m²

9) Flue gasToxicity rating: t2, no achievement of quasi-safety level ZA₃(t1, reaching the quasi-safe level of Tertiary ZA₃)

The GB8624-2012 test result shows that the smoke generation rate and the smoke generation total amount of the common phosphorus-nitrogen-boron flame retardant in the experiment are lower. But the toxicity of the smoke does not reach ZA₃And the flame retardant has high toxicity, and does not meet the requirement of obtaining flame retardant marks in GB 20286-.

Example 5

Preparing flame-retardant wood:

birch sawn timber with a thickness of 30mm was impregnated with the solution of flame retardant B of example 2 by the full cell method. The vacuum degree is-0.085 MPa for 30min before and 10min after the vacuum is finished. Pressurizing for 30min under 1.2 MPa. Stacking in a grid shape after dipping, ventilating and aging in the shade for over 72 hours, and drying in the room until the water content is about 10.5 percent. The solid drug-loading rate is 10.8 percent and the combustion performance reaches 'flame-retardant material' or B measured by flame-retardant wood₁(B) And (4) level requirements. The test results are as follows:

testing according to GB/T8625-2005 'test method for flame retardancy of building materials', the method meets the requirements of flame retardancy of building materials:

a) residual burning length 472(≥ 150) mm

b) The average smoke temperature is 107 (no more than 200) DEG C

Detecting the oxygen index by referring to GB/T2406.2-2009 part 2 of plastic oxygen index method for measuring combustion behavior:

oxygen index OI 41.2 (not less than 40)^{Note 1})％

(iii) experimental UL94 method (see UL94 horizontal combustion method for measuring combustion duration):

average burning time of 2.0 (less than or equal to 3)^{Note 2})s

Note 1: according to experimental data, the fire retardant reaches B of GB8624-2012₁(B) Grade, corresponding to an oxygen index of about 40% or more.

Note 2: according to experimental data, the fire retardant reaches B of GB8624-2012₁(B) And the corresponding afterburning time is less than or equal to 3 s.

Example 6

Preparing a flame-retardant wood particle board:

the particle for particle board was eucalyptus-miscellaneous wood, the flame retardant C solution of example 3 was applied by spraying at a drug loading of 5.5%, thoroughly stirred, spread open for ventilation aging for 72hr, and dried to a moisture content of 8.7% (top layer material) and 7.0% (core layer material). Then E with 60% solids is applied₁Urea-formaldehyde glue, the glue application amount is 5.5% (surface layer material) and 4.5% (core layer material) of oven-dried granules. After sizing, hot pressing the mixture in a laboratory according to the common urea-formaldehyde glue particle board process, and pressing the flame-retardant particle board sample at the temperature of 200 ℃ and the pressure of 12 MPa. Density of sample 622kg/m³Combustion performance up to B₁(C) And (4) level requirements. The test results are as follows:

detecting the oxygen index by referring to GB/T2406.2-2009 part 2 of plastic oxygen index method for measuring combustion behavior, room temperature test:

oxygen index OI 35.3 (not less than 33)^{Note 3})％

(ii) experimental method UL94 (measurement of combustion duration with reference to UL94 horizontal combustion method):

the average time of continuous combustion is 4.2 (less than or equal to 5)^{Note 4})s

Note 3: according to experimental data, the fire retardant reaches B of GB8624-2012₁(C) Grade, corresponding to an oxygen index of about 33% or more.

Note 4: according to experimental data, the fire retardant reaches B of GB8624-2012₁(C) And the corresponding afterburning time is less than or equal to 5 s.

Example 7

Preparing a flame-retardant straw particle board:

the particle for particle board is wheat straw, flame retardant C solution of example 3 is sprayed according to solid drug loading of 10.0%, fully stirred, spread out, ventilated and aged for 72hr, and then dried to water content of 7.0% (surface layer material) and 6.1% (core layer material). An emulsifiable polymeric MDI (polyphenyl polymethylene polyisocyanate) latex containing 60% solids was then applied in amounts of 5.0% (top layer material) and 4.3% (core layer material) of the oven dried particles. After sizing, an organic silicon release agent is adopted in a laboratory, and the flame-retardant particle board sample is pressed according to the common urea-formaldehyde glue particle board process at the temperature of 200 ℃ and the pressure of 12 MPa. Sample density 607kg/m³Combustion performance up to B₁(B) And (4) level requirements. The test results are as follows:

oxygen index OI 41.2 (not less than 40)^{Note 1})％

average time of continuous combustion is 2.2 (less than or equal to 3)^{Note 2})s

Example 8

Preparing a flame-retardant coconut palm plate:

the coconut palm plate is made of fiber filaments made of coconut shells, the filament length is more than or equal to 5cm, and the filament length of more than or equal to 10cm accounts for more than 70%. The solution of flame retardant C from example 3 was applied by spraying at a solid drug loading of 6.0%, stirred well, spread open for ventilation aging for 72hr, and dried to a moisture content of 9.0%. Then applying E with 50% solids₀Urea-formaldehyde glue, the glue application amount is 5% of oven-dry fiber. After sizing, hot pressing the mixture in a laboratory according to the common urea-formaldehyde glue particle board process, wherein the temperature is 200 ℃, and the pressure is 5MPa to press the flame-retardant coconut fiber board sample. Sample density 286kg/m³Combustion performance up to B₁(C) And (4) level requirements. The test results are as follows:

oxygen index OI 34.4 (not less than 33)^{Note 3})％

the average time of continuous combustion is 4.0 (less than or equal to 5)^{Note 4})s。

Claims

1. A preparation method of a silicon-boron-nitrogen ternary flame retardant for natural plant fiber materials is characterized in that each 1L of flame retardant is prepared from the following raw materials: 45-70 g of methyl sodium silicate or ethyl sodium silicate, 21-35 g of boric acid, 70-120 g of zinc sulfate solution or zinc nitrate solution with the mass concentration of 20%, 5.0-11.0 g of sulfuric acid solution with the volume concentration of 20%, 20-35 g of urea and the balance of water;

the preparation process comprises the following steps: