Extruded styrene resin foam and process for producing the same

Abstract

An extruded styrene resin foam obtained by extrusion-foaming of a styrene resin and excellent in environmental compatibility and excellent in flame retardant property and thermal insulating property, characterized in that it contains, as a blowing agent, 100 to 10% by weight of at least one of saturated hydrocarbons having 3 to 5 carbons and 0 to 90 % by weight of other blowing agent, based on the total amount of the blowing agent, and contains (A) a halogenated flame retardant and (B) at least one compound selected from the group consisting of phosphorus type flame retardants containing nitrogen atom in a molecule, tetrazole compounds, cyanuric acid and derivatives thereof, isocyanuric acid and derivatives thereof, metal borates, and boron oxides.

Description

field of invention [0001] The present invention relates to a styrene-based resin extruded foam with excellent environmental adaptability, excellent heat insulation and excellent flame retardancy and a manufacturing method thereof. Background of the invention [0002] A method of heating and melting a styrene-based resin in an extruder, etc., then adding a foaming agent, cooling it, and extruding it in a low-pressure zone to continuously obtain a foam is known (for example, JP-A-31-5393, Japanese Patent Publication No. 42-19195), and the method of using Flon (fluorocarbon) in the blowing agent is also known (for example, Japanese Patent Publication No. 41-672, Japanese Patent Publication No. 57-7175). [0003] However, from the viewpoint of ozone layer protection and the like, it is desirable to replace Freon if possible. [0004] Styrene-based resin extruded foam using a blowing agent other than Freon and method for producing the same, using propane, buta...

AI Technical Summary

Problems solved by technology

[0006] Unfortunately, in the non-Flon foam produced by the invention in the above-mentioned JP-A-10-237210, in order to adjust the residual gas amount of propane and butane to the above-mentioned amount, the foam production At the time and after manufacture, the following problems still exist: the addition amount of propane and butane is limited, long-term storage and other treatments are necessary until the blowing agent is reduced, and the stability and productivity of manufacture are poor, etc.

However, when a large amount of highly flammable aliphatic hydrocarbons represented by propane and butane remain, as in this invention, when only 1-3% by weight of hexabromocyclododecane or tetrabromobisphenol A is used, the Phenomenon that do not meet the flame retardancy specified in JIS A9511

In this regard, in order to improve the flame retardancy, it is proposed to increase the amount of flame retardant, but it is difficult to obtain stable flame retardancy only by increasing the amount

In particular, although the styrene-based resin itself, the base material of the foam, is flame-retardant, the hydrocarbons volatilized from the foam during combustion are easy to catch fire, and it is difficult to suppress combustion.

In addition, the multi-use of flame retardants will easily lead to the deterioration of the formability of the foam, making it difficult to produce high-quality molded products

[0008] Furthermore, in the invention of the above-mentioned Japanese Patent Application Laid-Open No. 7-53761, people worry that the storage time of the obtained foam will be prolonged and the storage cost will increase.

Moreover, this invention does not disclose necessary technologies such as the amount of blowing foam that should be injected into the extruder, and the appropriate amount of fireproofing agent, which brings considerable difficulties to industrial implementation.

In addition, in the examples of the invention, when butane is used as blowing agent by 100% by weight and butane / propane by weight ratio of 80 / 20, the desired fire resistance cannot be obtained