Urea resin foam material prepared by microwave foaming and preparation method of urea resin foam material

Abstract

The invention relates to a foam material and a preparation method thereof, in particular to a urea resin foam material prepared by microwave foaming and a preparation method of the urea resin foam material. The urea resin foam material is prepared by three steps and prepared from, by weight, 100 parts of urea resin available for microwave foaming, 1-5 parts of a foaming agent, 2-7 parts of a surfactant and 0.1-3.5 parts of a curing agent. A microwave heating method is adopted and assisted by oven heating for forming. The urea resin foam material and the preparation method thereof have advantages of high foaming efficiency, high foaming ratio, technical simplicity, low cost, high flame retardation performance and low fire risk and can be widely applicable to the field of exterior insulation of buildings.

Description

technical field

[0001] The invention relates to a foam material and a preparation method thereof, in particular to a urea-formaldehyde resin foam material prepared by microwave foaming and a preparation method thereof. Background technique

[0002] Because of its small bulk density, good thermal insulation effect, and excellent strength and elasticity, foam insulation materials are widely used in the fields of packaging, refrigeration, heat insulation, transportation, and external insulation of building exterior walls. At present, polyurethane foam and polystyrene foam are the most widely used foam insulation materials in the external insulation system of building exterior walls. Although these two materials have excellent comprehensive properties, they have a high risk of fire. With the improvement of people's living environment requirements, flame-retardant foam insulation materials have become the main direction of research.

[0003] Urea-formaldehyde resin foam material...

Examples

Embodiment 1

[0039] (1) Preparation of microwave foamable urea-formaldehyde resin

[0040] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.4:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 85°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 4.8 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 90°C, and react under these conditions until the viscosity reaches 18s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 6.0 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.6, add the third batch of urea, con...

Embodiment 2

[0052] (1) Preparation of microwave foamable urea-formaldehyde resin

[0053] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.3:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 85°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 5.1 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 95°C, and react under these conditions until the viscosity reaches 18.5s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 5.8 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.5, add the third batch of urea, c...

Embodiment 3

[0061] (1) Preparation of microwave foamable urea-formaldehyde resin

[0062] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.3:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 80°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 5.1 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 95°C, and react under these conditions until the viscosity reaches 18s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 5.8 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.6, add the third batch of urea, con...

technical field

[0001] The invention relates to a foam material and a preparation method thereof, in particular to a urea-formaldehyde resin foam material prepared by microwave foaming and a preparation method thereof. Background technique

[0002] Because of its small bulk density, good thermal insulation effect, and excellent strength and elasticity, foam insulation materials are widely used in the fields of packaging, refrigeration, heat insulation, transportation, and external insulation of building exterior walls. At present, polyurethane foam and polystyrene foam are the most widely used foam insulation materials in the external insulation system of building exterior walls. Although these two materials have excellent comprehensive properties, they have a high risk of fire. With the improvement of people's living environment requirements, flame-retardant foam insulation materials have become the main direction of research.

[0003] Urea-formaldehyde resin foam material...

Examples

Embodiment 1

[0039] (1) Preparation of microwave foamable urea-formaldehyde resin

[0040] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.4:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 85°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 4.8 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 90°C, and react under these conditions until the viscosity reaches 18s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 6.0 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.6, add the third batch of urea, con...

Embodiment 2

[0052] (1) Preparation of microwave foamable urea-formaldehyde resin

[0053] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.3:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 85°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 5.1 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 95°C, and react under these conditions until the viscosity reaches 18.5s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 5.8 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.5, add the third batch of urea, c...

Embodiment 3

[0061] (1) Preparation of microwave foamable urea-formaldehyde resin

[0062] Calculate the feeding amount with the molar ratio of urea and formaldehyde being 1.3:1, and add the weighed formaldehyde aqueous solution with a mass fraction of 37% into the reaction kettle in advance, and start stirring. Use 30% NaOH aqueous solution to adjust the pH value of formaldehyde to 8.8, then add the first batch of urea, and raise the temperature to 80°C for half an hour. Immediately after the heat preservation stage is over, adjust the pH value of the reaction system to 5.1 with 0.5 mol / L hydrochloric acid aqueous solution, and at the same time warm to 95°C, and react under these conditions until the viscosity reaches 18s. The temperature was lowered to 75° C., and the pH value of the system was adjusted to 5.8 with 30 wt % NaOH aqueous solution immediately, and the second batch of urea was added. After reacting for 30 minutes, adjust the pH value to 7.6, add the third batch of urea, con...

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