阅读说明：本技术 一种超支化型含磷硅脂肪胺阻燃固化剂及其制备方法和在防火涂料中的应用 (Hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, preparation method thereof and application thereof in fireproof coating ) 是由 刘治田 石遒 霍思奇 王成 叶国峰 于 2021-09-29 设计创作，主要内容包括：本发明公开了一种超支化型含磷硅脂肪胺阻燃固化剂,通过对三亚乙基四胺进行超支化并接枝有机磷杂菲等基团,得到所述超支化型含磷硅脂肪胺阻燃固化剂。利用本发明所述阻燃固化剂制备的防火涂料具有耐火时间长,耐水性好,附着力优异,干燥时间短,抗裂性好等优点,可有效兼具良好的阻燃和力学性能等；且涉及的制备工艺简单,成本较低,适合推广应用。(The invention discloses a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, which is obtained by hyperbranched triethylene tetramine and grafting organic phosphaphenanthrene and other groups. The fireproof coating prepared by the flame-retardant curing agent has the advantages of long fire-resistant time, good water resistance, excellent adhesive force, short drying time, good crack resistance and the like, and can effectively combine good flame retardance, mechanical property and the like; and the related preparation process is simple, the cost is lower, and the method is suitable for popularization and application.)

1. A preparation method of a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent is characterized by comprising the following steps:

1) dissolving triethylenetetramine in an organic solvent, and then dropwise adding trichloroethylene silane under the stirring condition to perform room-temperature reaction; then dropwise adding saturated solution of sodium carbonate; evaporating the organic solvent to dryness, dissolving in an alcohol solvent, filtering, and collecting the filtrate;

2) adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, azobisisobutyronitrile and an organic solvent into the filtrate obtained in the step 1), carrying out heat preservation reaction under the stirring condition, and evaporating the solvent; dissolving the obtained solid product in an alcohol solvent, filtering, collecting filtrate, and evaporating the solvent to dryness; and dissolving in water, filtering, collecting filtrate, evaporating to dryness and drying to obtain the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent.

2. The preparation method of claim 1, wherein the room temperature reaction time in the step 1) is 3-5 h.

3. The preparation method of claim 1, wherein the molar ratio of triethylenetetramine to trichloroethylsilane is 3:2 to 2: 1.

4. The preparation method according to claim 1, wherein the molar ratio of triethylenetetramine to introduced sodium carbonate is 1:2 to 2: 1.

5. The preparation method according to claim 1, wherein the molar ratio of triethylenetetramine to DOPO is 3:2 to 2: 1.

6. The method according to claim 1, wherein the molar ratio of triethylenetetramine to AIBN is 30:2 to 20: 1.

7. The preparation method of claim 1, wherein the mass ratio of the triethylenetetramine to the alcohol solvent introduced in the dissolving step in step 1) or 2) is 1: 5-5: 1; the mass ratio of the triethylenetetramine to the water introduced in the dissolving step in the step 2) is 1: 5-5: 1.

8. The preparation method of claim 1, wherein the reaction temperature in the step 2) is 80-120 ℃ and the reaction time is 12-24 hours.

9. The hyperbranched phosphorus-silicon-containing aliphatic amine flame retardant curing agent prepared by the preparation method of any one of claims 1 to 8.

10. The application of the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent in the fireproof coating is characterized in that the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent comprises the following components in percentage by mass: 5-30% of hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, 35-60% of epoxy resin, 15-20% of ammonium polyphosphate, 10-20% of pentaerythritol, 10-15% of melamine, 1-5% of titanium dioxide, 0.5-1% of hydroxyethyl cellulose, 0.5-1% of dispersing agent, 0.5-1% of defoaming agent and 0.5-1% of n-octyl alcohol.

Technical Field

The invention belongs to the technical field of fireproof coatings, and particularly relates to a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, a preparation method thereof and application thereof in fireproof coatings.

Background

The intumescent fire-retardant coating generally comprises an adhesive, an intumescent flame-retardant system and a filler auxiliary agent, when a fire disaster happens, the adhesive is melted, an acid source in the intumescent flame-retardant system is decomposed to release an acid substance, the acid substance promotes the adhesive and a carbon source to be dehydrated and carbonized, so that a gas source is decomposed, a non-combustible gas is released and viscous-state coke is generated, and the adhesive and the carbon source are combined to form a honeycomb-shaped carbon layer, so that air and heat transfer are isolated, and an excellent fire-proof and heat-insulating effect is achieved.

Epoxy resin is the most widely used thermosetting material at present, and epoxy resin taking aliphatic amine as a curing agent is often used as an adhesive of adhesives and coatings due to the low glass transition temperature and curing temperature, fast reaction, insulation and good adhesion. The coating prepared by the curing agent is quick in curing, moderate in temperature and good in transparency; and are therefore often used as film formers for intumescent fire-retardant coatings.

However, the aliphatic amine curing agent has the defects of volatility, strong toxicity and the like, and the use is often limited along with the improvement of environmental protection consciousness of people in recent years. Meanwhile, the epoxy resin cured by the aliphatic amine curing agent has poor mechanical properties due to lack of rigid groups among chains, so that the application range of the epoxy resin is limited, and the epoxy resin has extremely poor thermodynamic properties due to low glass transition temperature, so that flame combustion is promoted in a fire, which is unfavorable for protecting steel. In patent CN109535889A, triethylenetetramine is used as a curing agent of epoxy-based fire-retardant coating, and it does not undergo flame-retardant modification, and mainly plays a role of binder.

Therefore, the preparation method further improves the aliphatic amine curing agent, explores and optimizes the preparation process of the fireproof coating, and has important practical application value and research significance.

Disclosure of Invention

The invention mainly aims to provide a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent and a fireproof coating prepared by using the same, aiming at the defects in the prior art, the fireproof coating obtained by the flame-retardant curing agent has the advantages of long fire-resistant time, good water resistance, excellent adhesive force, short drying time, good crack resistance and the like, and the obtained fireproof coating has good flame retardance, mechanical properties and the like; and the related preparation process is simple, the cost is lower, and the method is suitable for popularization and application.

In order to achieve the purpose, the invention adopts the technical scheme that:

a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent and a preparation method thereof comprise the following steps:

1) dissolving triethylenetetramine in an organic solvent, and then dropwise adding trichloroethylene silane under the stirring condition to perform room-temperature reaction; then dropwise adding saturated solution of sodium carbonate (hydrochloric acid which is a byproduct of the neutralization reaction); evaporating the organic solvent to dryness, dissolving in an alcohol solvent, filtering, and collecting the filtrate;

2) adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), Azobisisobutyronitrile (AIBN) and an organic solvent into the filtrate obtained in the step 1), carrying out heat preservation reaction under the condition of stirring, and evaporating the solvent to dryness; dissolving the obtained solid product in an alcohol solvent, filtering, collecting filtrate, and evaporating the solvent to dryness; and dissolving in water, filtering, collecting filtrate, evaporating to dryness and drying to obtain the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent.

In the scheme, the organic solvent can be DMF and the like; the alcohol solvent can be selected from anhydrous ethanol, etc.

In the scheme, the triethylene tetramine is added into an organic solvent at the temperature of-10-0 ℃; the dropping time of the trichlorosilane is 1-1.5 h.

In the scheme, the room-temperature reaction time in the step 1) is 3-5 h.

In the scheme, the mass ratio of the triethylenetetramine to the DMF is 1: 5-5: 1.

In the scheme, the molar ratio of the triethylenetetramine to the trichlorosilane is 3: 2-2: 1.

In the scheme, the molar ratio of the triethylenetetramine to the introduced sodium carbonate is 1: 2-2: 1.

In the scheme, the molar ratio of the triethylenetetramine to the DOPO is 3: 2-2: 1.

In the scheme, the molar ratio of the triethylenetetramine to the AIBN is 30: 2-20: 1.

In the scheme, the mass ratio of the triethylenetetramine to the alcohol solvent introduced in the dissolving step in the step 1) or 2) is 1: 5-5: 1.

In the scheme, the mass ratio of the triethylenetetramine to the water introduced in the dissolving step in the step 2) is 1: 5-5: 1.

In the scheme, the temperature of the heat preservation reaction in the step 2) is 80-120 ℃, and the time is 12-24 hours.

In the scheme, the drying temperature in the step 2) is 80-110 ℃, and the time is 18-24 h.

The invention also provides a fire-retardant coating based on the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, which comprises the following components in percentage by mass: 5-30% of hyperbranched triethyl tetraamine phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, 35-60% of epoxy resin, 15-20% of polyphosphoric acid, 10-20% of pentaerythritol, 10-15% of melamine, 1-5% of titanium dioxide, 0.5-1% of hydroxyethyl cellulose, 0.5-1% of dispersing agent, 0.5-1% of defoaming agent and 0.5-1% of n-octyl alcohol.

In the above scheme, the epoxy resin is E44, E51, E53 type bisphenol a type epoxy resin, bisphenol F type epoxy resin, or the like.

In the scheme, the dispersant is wetting dispersant 5040 and the like.

In the scheme, the defoaming agent is an organic silicon defoaming agent 470 and the like.

The principle of the invention is as follows:

according to the invention, the triethylene tetramine is hyperbranched and grafted with the organic phosphaphenanthrene group, so that linear small-molecule triethylene tetramine is changed into hyperbranched macromolecules, the volatility of the hyperbranched macromolecules is reduced, and the toxicity of the hyperbranched macromolecules is further reduced; meanwhile, a phosphaphenanthrene group is introduced between chains, so that the glass transition temperature of the cured epoxy resin is increased; the cured fireproof coating has a special structure of silicon-phosphaphenanthrene on a molecular scale, so that the gas phase quenching effect of DOPO and the network condensed phase effect formed by siloxane can be simultaneously exerted, and the flame retardant property of the obtained fireproof coating is greatly improved; meanwhile, the hyperbranched line-type macromolecular curing agent can increase the acting force between chains, so that the mechanical property of the epoxy resin cured by the hyperbranched line-type macromolecular curing agent is greatly improved, and the mechanical property of the fireproof coating is synchronously and effectively improved.

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

1) the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent can simultaneously play the gas phase quenching effect of DOPO and the network condensed phase effect formed by siloxane, and synergistically improve the fireproof effect of the curing agent and the fireproof coating; meanwhile, the acting force between chains can be increased, and the mechanical property of the obtained fireproof coating is synchronously improved;

2) the fireproof coating has the advantages of long fireproof time, good water resistance, excellent adhesive force, short drying time, good crack resistance and the like, can have good flame retardance, mechanical property and the like, and is suitable for popularization and application.

Drawings

FIG. 1 is a schematic structural diagram of a hyperbranched phosphorus-silicon-containing aliphatic amine flame retardant curing agent obtained in example 1;

FIG. 2 is a nuclear magnetic resonance hydrogen spectrum of the hyperbranched phosphorus-silicon-containing aliphatic amine flame retardant curing agent obtained in example 1;

FIG. 3 is a nuclear magnetic resonance phosphorus spectrum of the hyperbranched phosphorus-containing silicon aliphatic amine flame retardant curing agent obtained in example 1;

FIG. 4 is a UL-94 digital photograph of a specimen bar of E51 epoxy resin prepared from the hyperbranched phosphorus-containing silicon aliphatic amine flame retardant curing agent obtained in example 1;

FIG. 5 is a graph showing the back temperature of the intumescent coating obtained in application example 1 and comparative example by the big panel combustion method.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail with reference to the following embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

In the following examples, the dispersant used was wetting dispersant 5040; the defoaming agent is a silicone defoaming agent 470.

Example 1

A hyperbranched phosphorus-silicon containing aliphatic amine flame retardant curing agent has a chemical structure as shown in figure 1; the preparation method comprises the following steps:

1) dissolving 25g of triethylenetetramine in 125g of DMF at 0 ℃, keeping stirring, dropwise adding 16.76g of trichloroethylsilane (the molar ratio of triethylenetetramine to trichloroethylsilane is 3.3:2) into the solution within 1h, reacting at room temperature for 5h after dropwise adding, and dropwise adding a saturated solution of sodium carbonate (the molar ratio of triethylenetetramine to introduced sodium carbonate is 1:2) into the solution after the reaction; evaporating solvent DMF, dissolving in anhydrous ethanol, and filtering to obtain filtrate;

2) adding 24.6g of DOPO (9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, the molar ratio of triethylene tetramine to DOPO is 3:2), 1.4g of AIBN (azobisisobutyronitrile, the molar ratio of triethylene tetramine to AIBN is 20:1) and 125g of DMF into the filtrate obtained in the step 1), keeping stirring, reacting at the temperature of 80-120 ℃ for 12 hours, evaporating the DMF as a solvent, dissolving in 125g of absolute ethyl alcohol, filtering, taking the filtrate, and evaporating the absolute ethyl alcohol; dissolving in 125g water, filtering, collecting filtrate, and evaporating water; drying for 18-24 h at 80 ℃ to obtain the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent.

Fig. 2 and fig. 3 are a nuclear magnetic resonance hydrogen spectrum and a nuclear magnetic resonance phosphorus spectrum of the hyperbranched phosphorus-containing aliphatic amine flame retardant curing agent obtained in this embodiment, respectively, and the results show that: corresponding peaks of DOPO and triethylenetetramine appear in a nuclear magnetic resonance hydrogen spectrum, and only one phosphorus single peak exists in a nuclear magnetic resonance phosphorus spectrum.

FIG. 4 is a UL-94 digital photograph of a specimen bar of E51 epoxy resin prepared from the hyperbranched phosphorus-containing silicon aliphatic amine flame retardant curing agent obtained in the present example.

Application example 1

A fire-retardant coating based on a hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent comprises the following components in percentage by mass: 10% of the hyperbranched triethyl tetraamine-based phosphorus and silicon containing aliphatic amine flame retardant curing agent obtained in example 1, 50% of E51 type epoxy resin, 15% of ammonium polyphosphate, 10% of pentaerythritol, 10% of melamine, 3% of titanium dioxide, 0.5% of hydroxyethyl cellulose, 0.5% of dispersant, 0.5% of defoamer and 0.5% of n-octanol, wherein the preparation method comprises the following steps:

1) weighing the raw materials according to the proportion requirement;

2) grinding the weighed ammonium polyphosphate, pentaerythritol, melamine and titanium dioxide to be powder without particles, and then adding water, fully grinding and uniformly mixing; adding the defoaming agent and the dispersing agent, and continuously and fully grinding;

3) and finally, adding a hyperbranched triethyl tetramino phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, E51 epoxy resin and n-octanol, fully grinding and uniformly mixing to obtain the fireproof coating.

Application example 2

A fire-retardant coating based on hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent has a preparation method which is substantially the same as that of application example 1, and is characterized in that the fire-retardant coating comprises the following components in percentage by mass: the flame-retardant coating comprises 15% of hyperbranched triethyl tetramine phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, 45% of E51 epoxy resin, 15% of polyphosphoric acid amine, 10% of pentaerythritol, 10% of melamine, 3% of titanium dioxide, 0.5% of hydroxyethyl cellulose, 0.5% of dispersing agent, 0.5% of defoaming agent and 0.5% of n-octyl alcohol.

Application example 3

A fire-retardant coating based on hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent has a preparation method which is substantially the same as that of application example 1, and is characterized in that the fire-retardant coating comprises the following components in percentage by mass: 20 percent of hyperbranched triethyl tetramine phosphorus-silicon-containing aliphatic amine flame-retardant curing agent, 40 percent of E51 type epoxy resin, 15 percent of polyphosphoric acid, 10 percent of pentaerythritol, 10 percent of melamine, 3 percent of titanium dioxide, 0.5 percent of hydroxyethyl cellulose, 0.5 percent of dispersant, 0.5 percent of defoamer and 0.5 percent of n-octyl alcohol.

Comparative example 1

The preparation method of the water-based intumescent fire-retardant coating is almost the same as that of application example 1, and is characterized in that the water-based intumescent fire-retardant coating comprises the following components in percentage by mass: 10% of triethyltetramine, 50% of E51 type epoxy resin, 15% of polyphosphoric acid, 10% of pentaerythritol, 10% of melamine, 3% of titanium dioxide, 0.5% of hydroxyethyl cellulose, 0.5% of dispersing agent, 0.5% of defoaming agent and 0.5% of n-octyl alcohol.

The intumescent fire-retardant coatings obtained in examples 1-3 and comparative example 1 were subjected to fire resistance tests, and the results are shown in table 1.

Comparative example 2

The preparation method of the water-based intumescent fire-retardant coating is almost the same as that of application example 1, and is characterized in that the water-based intumescent fire-retardant coating comprises the following components in percentage by mass: 10% of triethyltetramine, 5% of DOPO, 45% of E51 type epoxy resin, 15% of ammonium polyphosphate, 10% of pentaerythritol, 10% of melamine, 3% of titanium dioxide, 0.5% of hydroxyethyl cellulose, 0.5% of dispersing agent, 0.5% of defoaming agent and 0.5% of n-octyl alcohol.

The intumescent fire-retardant coatings obtained in application examples 1-3 and comparative examples 1-2 are respectively subjected to tests of flame retardant property, mechanical property, durability and the like, and the results are shown in table 1.

TABLE 1 Performance test results of the intumescent coatings obtained in examples 1-3 and comparative example 1

The above results show that: the fireproof coating prepared by the hyperbranched phosphorus-silicon-containing aliphatic amine flame-retardant curing agent can effectively give consideration to excellent flame-retardant effect and mechanical property, is environment-friendly, pollution-free, good in durability, compatible with a substrate and good in adhesiveness, and is suitable for popularization and application. The preparation method provided by the invention is simple and effective, and has a wide application field.

It is apparent that the above embodiments are only examples for clearly illustrating and do not limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications are therefore intended to be included within the scope of the invention as claimed.