Low-density flame-retardant semi-rigid polyurethane foam and preparation method thereof

Abstract

The invention discloses low-density flame-retardant semi-rigid polyurethane foam and a preparation method thereof. The low-density flame-retardant semi-rigid polyurethane foam is composed of an composition A and an composition B, the composition A comprises, in parts by weight, 70 parts of a combined polyether polyol, 0.2-1.5 parts of a surfactant, 0.1-1.0 part of a catalyst and 15-40 parts of a flame retardant; and the composition B comprises 110-230 parts by weight of MDI system isocyanate. The composition A and the composition B are fully mixed for reaction and further for forming polyurethane foam. The polyurethane foam has the density of 8-25 Kg / m<3>, the compression strength scope of 10-60 KPa, the rupture elongation of 12-50% and the open porosity of 90-99%, and the flame-retardant performance is capable of satisfying flame-retardant requirements of automobile interior trim flame retardance standard FMVSS302 and Volkswagen PV3937.

Description

technical field [0001] The invention belongs to the field of polyurethane foam plastics, and in particular relates to a low-density flame-retardant semi-rigid polyurethane foam and a preparation method thereof. The flame-retardant semi-rigid polyurethane foam can be applied to automobile hoods, outer sides of cowls, channels and other components. Background technique [0002] Generally speaking, polyurethane soft foam is mainly used in the field of furniture. The foam is open-celled, soft, and has a high elongation at break. Polyurethane rigid foam is mainly used in thermal insulation materials in construction and household appliances. Brittle. Polyurethane semi-rigid foam is a material between soft foam and rigid foam. It has some characteristics of both. It is mainly used in packaging, automobile and other industries. In these application fields, the foam is either cut into the required shape, or the reaction raw material is poured into the mold for reaction molding. How...

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Problems solved by technology

[0004] CN1235622A discloses a method for preparing an open-cell rigid polyurethane foam. The cell opener includes polyoxyalkylene polysiloxane with a cloud point of 65°C and a material with a critical surface free energy of less than about 23mJ / m2. The material is preferably fine-grained polytetrafluoroethylene polymer. This cell-opening agent has poor compatibility with polyols and is easily separated from other components in the combined polyether, causing difficulties in storage and use.

[0006] CN102504180, CN101117399 relate to the manufacture method of the polyurethane foam used in the roof, the foam density and the compression strength are high, it is used in the roof of the car, and polyester polyol is used, it is easy to cause problems such as the delamination of the combined polyether and the size shrinkage of the foam

[0007] CN1102418A discloses a method for preparing open-cell rigid polyurethane foam, wherein the polyol mixture has a hydroxyl value of 160-360 mgKOH / g, and the prepared foam has a high degree of crosslinking and poor brittleness, and cannot be thermoplastically formed

[0008] CN1142513A discloses a preparation method of open-cell rigid polyurethane foam, which is used as insulation material for refrigerators and insulation materials for interior and exterior walls of buildings. The hydroxyl-terminated product can open cells in the foam, but its viscosity is high, resulting in the formation of polyols High viscosity, poor fluidity, low yield

[0010] CN1508166A discloses a flexible polyurethane foam with a density of 4-30kg / m3, which is characterized by open cells, high resilience, low modulus, high indentation coefficient and low hysteresis loss. There is no major glass-to-rubber transition between +25°C, the E'-100°C / E'+25°C ratio is 1.3-15, but this type of foam has low hardness, insufficient rigidity and support

The patent does not mention the dimensional stability and physical properties of the foam

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