阅读说明：本技术 一种阻燃超低导热系数pfu泡沫及其制作方法 (Flame-retardant PFU foam with ultralow heat conductivity coefficient and preparation method thereof ) 是由 杨金平 陈士景 高源� 于 2020-07-08 设计创作，主要内容包括：本发明涉及一种阻燃超低导热系数PFU泡沫及其制作方法,原料包括PFU树脂、泡沫稳定剂、催化剂、改性剂、发泡剂等,将原料按比例混合然后搅拌均匀得到混合物；将上述混合物与异氰酸酯混合,高速搅拌均匀后注入模具；将上述模具在55～65℃温度下进行发泡固化成型得到阻燃超低导热系数PFU泡沫。与现有技术相比,本发明PFU泡沫不仅具有聚氨酯泡沫的优良物理性能还兼具酚醛泡沫的难燃、耐酸腐蚀、遇火表面炭化、离火自熄等优越性能；况且它的氧指数最高可达30以上,燃烧性能等级可达难燃B<Sub>1</Sub>级；它的导热系数极低,低的可达到0.0162W/K·m。本此外还具有绝热、质轻、高强度等优良性能外,因此它是有机保温材料中保温效果最好的。(The invention relates to a flame-retardant PFU foam with ultralow heat conductivity coefficient and a preparation method thereof, wherein the raw materials comprise PFU resin, a foam stabilizer, a catalyst, a modifier, a foaming agent and the like, and the raw materials are mixed in proportion and then uniformly stirred to obtain a mixture; mixing the mixture with isocyanate, stirring uniformly at a high speed, and injecting into a mold; and foaming, curing and molding the die at the temperature of 55-65 ℃ to obtain the flame-retardant PFU foam with ultralow heat conductivity coefficient. Compared with the prior art, the PFU foam has the excellent physical properties of polyurethane foam, and also has the flame resistance, acid corrosion resistance and fire surface of phenolic foamSuperior performances such as surface carbonization, self-extinguishing when away from fire and the like; moreover, the oxygen index of the flame retardant can reach more than 30 at most, and the combustion performance grade can reach flame retardant B 1 A stage; its thermal conductivity coefficient is very low, and can be up to 0.0162W/K.m. Besides excellent properties of heat insulation, light weight, high strength and the like, the material has the best heat insulation effect in organic heat insulation materials.)

1. The flame-retardant PFU foam with ultralow heat conductivity coefficient is characterized by comprising the following components in parts by weight: 100 parts of PFU resin, 1-6 parts of foam stabilizer, 0-5 parts of catalyst, 0-20 parts of modifier, 10-30 parts of foaming agent and 180 parts of isocyanate 130-.

2. The flame retardant PFU foam of claim 1, wherein said PFU resin is a mixture of viscosity: PFU resin with 400-1500cPa and moisture content lower than 1.5%.

3. The flame retardant PFU foam according to claim 1 wherein said foam stabilizer is selected from the group consisting of one or more of Tween 80, CGY-1, AK8801, AK 8806.

4. The flame retarded ultra low thermal conductivity PFU foam according to claim 1, wherein said catalyst is an organotin species.

5. The flame-retardant PFU foam according to claim 1 wherein said modifier is diisopropanolamine and polyethylene glycol 200 in a mass ratio of 1: 5-10 of a mixed solution.

6. The flame retardant PFU foam of claim 1, wherein said blowing agent is one or more selected from pentane, cyclopentane, 141 b.

7. The flame retardant PFU foam of claim 1, wherein said isocyanate is one or more of 44V20, PM400, PAPI.

8. A method for making a flame retardant PFU foam according to any of claims 1 to 7 comprising the steps of:

(1) preparing the following components in parts by weight: 100 parts of PFU resin, 1-6 parts of foam stabilizer, 0-5 parts of catalyst, 0-20 parts of modifier, 10-30 parts of foaming agent and 180 parts of isocyanate 130-;

(2) PFU resin, a foam stabilizer, a catalyst, a modifier and a foaming agent are added into a proportioning container according to a formula and then are uniformly stirred to obtain a mixture;

(3) mixing the mixture with isocyanate, stirring uniformly at a high speed, and injecting into a mold;

(4) and foaming, curing and molding the mold to obtain the flame-retardant PFU foam with ultralow heat conductivity coefficient.

9. The method for preparing the flame-retardant PFU foam with ultralow thermal conductivity according to claim 8, wherein the stirring speed of the high-speed stirring in the step (3) is 800-1200 rmp.

10. The method for preparing the PFU foam with flame retardant and ultralow thermal conductivity according to claim 8, wherein the temperature for foaming, curing and molding in the step (3) is 55-65 ℃.

Technical Field

The invention relates to the field of heat-insulating foam industry, in particular to a flame-retardant PFU foam with ultralow heat conductivity coefficient and a preparation method thereof.

Background

At present, polyurethane foam materials and phenolic foam materials in the polymer material market at home and abroad have a relatively large share in the application fields of heat insulation, green energy conservation and the like. The polyurethane foam material is prepared by uniformly mixing materials such as polyol, a foaming agent, a foam stabilizer, an auxiliary agent, isocyanate and the like, and then foaming and curing the mixture. It has the advantages of light weight, high strength, low water absorption, low thermal conductivity, and good performance of combining with various materials; but because the polyurethane material belongs to flammable materials, the oxygen index is 17; therefore, fire caused by fire of polyurethane material occurs, and the polyurethane material can be burnt and decomposed to generate a large amount of NO and NO₂And toxic smog such as HCN causes great harm to life and property safety. It has poor combustion performance, and can only reach B₂And (4) stages. The method is mainly applied to the fields of chemical industry, petroleum, buildings and the like. Along with the progress of society and the development of science and technology, the safety precaution consciousness of people is gradually strengthened, and the requirement on the flame-retardant and fireproof performance of building materials is higher and higher.

The phenolic foam material is a novel high polymer material heat insulation material, is prepared by uniformly mixing phenolic resin, a foam stabilizer, a foaming agent, an auxiliary agent, a curing agent and the like, and then foaming and curing at high temperature, and has the combustion performance reaching the flame retardant B₁The grade, the heat conductivity coefficient is 0.028-0.035W/K.m. But it is brittle and easily pulverized; and the foam material contains acidity and is easy to corrode metal objects.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provide a flame-retardant PFU foam with ultralow thermal conductivity and a preparation method thereof. The invention integrates the advantages of polyurethane foam material and phenolic foam material together to prepare the foam heat-insulating material, the heat conductivity coefficient of the foam heat-insulating material is between 0.016 and 0.026W/K.m, the combustion performance is nonflammable B1 grade, the foam material has no powder, is neutral per se and does not contain acidity.

The purpose of the invention can be realized by the following technical scheme: the flame-retardant PFU foam with ultralow heat conductivity coefficient is characterized by comprising the following components in parts by weight: 100 parts of PFU resin, 1-6 parts of foam stabilizer, 10-25 parts of flame retardant, 0-5 parts of catalyst, 0-20 parts of modifier, 10-30 parts of foaming agent and 180 parts of isocyanate 130-one.

The PFU resin is viscosity: 400-1500cPa and the water content is lower than 1.5 percent of PFU resin, the PFU resin is prepared by reacting and synthesizing phenols, aldehydes, catalysts and modifiers at high temperature, and the specific preparation method comprises the following steps: putting phenols (such as phenol), aldehydes (such as formaldehyde), catalysts (such as zinc acetate) and modifiers (such as diisopropanolamine) accounting for 50 wt% of the total amount into a reaction kettle, heating to 80-90 ℃, carrying out heat preservation reaction for 30-60min, continuously heating to 114-126 ℃, carrying out heat preservation reaction for 90-120min, adding the rest modifiers, carrying out vacuum dehydration for 10-40min, and cooling to obtain the PFU resin. Wherein the mass ratio of the phenols, the aldehydes, the catalyst and the modifier is 1: 0.5-0.6: 0.05-0.08: 0.2-0.3.

The PFU resin adopted by the invention has good intersolubility with isocyanate, auxiliary agent and other components, and has excellent processing performance. The foaming agent, the foam stabilizer, the catalyst, the modifier, the isocyanate and other materials are uniformly mixed, the compatilizer is good, the catalyst consumption is low, the foaming curing temperature is low, the obtained product has excellent performances of heat insulation, light weight, high strength and the like, and the combustion performance of the product is enhanced, so that the oxygen index of the foam can reach more than 38.

The foam stabilizer is selected from one or more of Tween 80, CGY-1, AK8801 and AK 8806. The foam stabilizer is proved to be one of key components in foam production, the foam stabilizer enables air holes to be fine and uniform, when a system is in a low viscosity stage, the hole wall is stabilized/the air holes can grow to be suitable for the thickness of open holes, conditions are created for the final open holes, the foam types are different, the types of the used stabilizers are different, the foam stabilizer mainly plays a role in nucleating and emulsifying each component in a formula, the compatibility of each component in the foam formula is not good, so a stabilizer with strong emulsifying capacity is needed to emulsify and mix the components, the foam stabilizer selected by the invention accounts for 1-6% of the weight of PFU resin in the formula, the compatibility of other components in the formula can be improved, in addition, the reaction speed of the PFU resin and isocyanate is high, therefore, a large amount of solid polyurea is generated in the initial foaming stage, and the foam stabilizer selected by the invention can be used as an antifoaming agent at the same time, the foam stabilizer can help to open and explode the pores, avoids the phenomenon of closed pores, and causes the reduction of the performance of the foam, but the open and explode the pores must appear when the foaming reaction and the gel reaction are basically completed and reach balance, namely when the foam rises to the highest point and the strength of the foam can support the self weight, otherwise the foam can collapse, so that the foam stabilizer has another important function of helping to open and explode the pores in the later foaming period by dissolving the polyurea generated by the reaction in the initial foaming period; the foam stabilizer selected by the invention can improve the intersolubility of the foaming agent and the PFU resin, so that the materials are mixed more uniformly, and the obtained foam is more uniform.

The catalyst is an organic tin substance, preferably 1-3 parts by weight, and comprises dibutyltin dilaurate, stannous octoate, dibutyltin diacetate and the like. The organic tin salt is used as the catalyst of the invention because the organic tin salt is dissolved in the polyhydric alcohol and the organic solvent, is insoluble in water and has good thermal stability; the influence of temperature is small when the catalysis is carried out, and the quality problem can not occur when the foam is formed.

The modifier is composed of diisopropanolamine and polyethylene glycol 200 in a mass ratio of 1: 5-10 parts by weight of the mixed solution, preferably 8-12 parts by weight. The grafting of diisopropanolamine can obviously improve the comprehensive performance of PFU resin; solves the problems of quick initiation, slow curing and the like in the foaming process. The problems of quick initiation, slow solidification, poor material foaming fluidity and the like in the foaming process can be better solved by adopting a mixed solution of diisopropanolamine and polyethylene glycol 200; the prepared foam is more uniform and has better flame retardance, dimensional stability and compressive strength.

The foaming agent is one or more of pentane, cyclopentane and 141 b. In the early stage of mixing and foaming PFU resin and material components, a large amount of heat is generated, and the foaming agent selected by the invention can absorb part of the heat during gasification, and simultaneously, the reaction material is expanded, foamed and solidified. 141b as the foaming agent, has good compatibility with the polyol and the isocyanate, and has low gas heat conductivity and low temperature required by foaming; cyclopentane and pentane are used as foaming agents, ODP value and GWP value of cyclopentane are zero, and the mutual solubility of cyclopentane, PFU resin and other materials can be increased through the cooperation of foam stabilizer, so that the materials are more uniform, and foams are more homogeneous.

The isocyanate is one or more of 44V20, PM400 and PAPI. The isocyanate and a large amount of hydroxyl in the PFU resin are subjected to chain extension, crosslinking reaction and foaming reaction to generate reaction heat, so that the temperature of a material system is increased, the low-boiling-point foaming agent HCFC-141b is volatilized into gas, uniform bubbles are formed under the action of a foam stabilizer, and finally, the uniform bubbles are solidified to form foam.

The invention also provides a preparation method of the flame-retardant PFU foam with ultralow heat conductivity coefficient, which comprises the following steps:

(1) preparing the following components in parts by weight: 100 parts of PFU resin, 1-6 parts of foam stabilizer, 10-25 parts of flame retardant, 0-5 parts of catalyst, 0-20 parts of modifier, 10-30 parts of foaming agent and 180 parts of isocyanate 130-one;

(2) PFU resin, foam stabilizer, flame retardant, catalyst, modifier and foaming agent are added into a proportioning container according to the formula and then are uniformly stirred to obtain a mixture;

(3) mixing the mixture with isocyanate, stirring uniformly at a high speed, and injecting into a mold;

(4) and foaming, curing and molding the die at the temperature of 55-65 ℃ to obtain the flame-retardant PFU foam with ultralow heat conductivity coefficient.

And (4) stirring speed of the high-speed stirring in the step (3) is 800-1200 rmp.

The foam of the invention is prepared by mixing PFU resin, foam stabilizer, catalyst, foaming agent and the like uniformly according to a proportion to prepare a polyol component (white material), and isocyanate is another component (black material); the two components are uniformly mixed according to a proportion and then are foamed and molded to prepare the organic heat-insulating material, which has the best heat-insulating effect in the organic heat-insulating material; its thermal conductivity coefficient is very low, can reach 0.0162W/K.m. The conventional polyurethane resin has a combustible hydrocarbon chain segment, small density and large specific surface area, is easy to burn and decompose when encountering fire, and generates a large amount of toxic smoke; the PFU foam adopted by the application can be just cooperated with the flame retardant of the invention to improve the flame retardant property of the polyurethane foam. The common rigid polyurethane foam has good mechanical property and excellent heat insulation performance, has stronger bonding force with most inorganic materials such as metal and the like (generally greater than the shearing strength and the tensile strength of the foam), has larger penetration resistance to water and water vapor, stable chemical property and slow aging speed; however, the grade of the combustion performance of the foam can only reach B2 grade, and the foam product obtained by compounding the PFU resin and other components has the excellent physical properties of polyurethane foam, and also has the excellent properties of flame resistance, acid corrosion resistance, charring on the surface in case of fire, self-extinguishing when away from fire and the like of phenolic foam, and moreover, the grade of the combustion performance of the foam product can reach B1 grade.

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

1. the invention selects the transparent liquid PFU resin with low viscosity and lower water content to completely replace the conventional polyester or polyether polyol, has good intersolubility with isocyanate and auxiliary agent, and has excellent processing performance.

2. The PFU foam material has a low coefficient of thermal conductivity which can reach 0.0162W/K.m.

3. The PFU foam material has good flame retardant property, and the oxygen index of the PFU foam material is higher and can reach 41.

4. The PFU foam material product has the excellent physical properties of environmental friendliness, energy conservation, low density, high strength, flame retardancy, acid corrosion resistance, surface carbonization in case of fire, self-extinguishing when away from fire and the like; the combustion performance grade can reach the flame-retardant B1 grade.

5. The PFU foam has the excellent physical properties of polyurethane foam, and also has the advantages of flame resistance, acid corrosion resistance, charring in case of fire, self-extinguishing when away from fire and the like of phenolic foam; and its oxygen index is higher, and can be up to 41, and its combustion performance grade can be up to fire-retardant B₁A stage; the heat conductivity coefficient is extremely low and can reach 0.0162W/K.m. In addition, the material has excellent performances of heat insulation, light weight, high strength and the like, so that the material has the best heat insulation effect in organic heat insulation materials.

Detailed Description

The following examples are given for the detailed implementation and specific operation of the present invention, but the scope of the present invention is not limited to the following examples.