An Apple patent (number 20110144244) for halogen-free, flame retardant material has appeared at the US Patent & Trademark Office that shows what future Mac and iOS products could be made of — at least in part.
The disclosure describes halogen free flame retardant resin compositions comprising at least one thermoplastic polymer; an inorganic filler; and a flame retardant additive, wherein the flame retardant additive is an alkali metal nitrite; an alkaline earth metal nitrite; an alkali metal nitride; an alkaline earth metal nitride; an alkali metal borate; an alkaline earth metal borate; an alkali metal silicide; an alkaline earth metal silicide; an alkali metal silicate; or an alkaline earth metal silicate. Also described are computing systems having components formed of such a halogen free, flame retardant resin. Jean L. Lee is the inventor.
Here’s Apple’s background of the invention: “It has been estimated that about 10% of fires are caused by electrical faults of wiring and electrical equipment, and that these fires account for 19% of fire-related injuries. Some plastics are inherently resistant to fire, such as polyvinylchloride (PVC). However, PVC is not suitable for many electronics applications. Only about 12% of plastics used today contain flame retardants. An increased use of flame retardants would improve the safety of electrical wiring and electronic devices, and therefore reduce the number of fires caused by electronic devices.
“Halogenated flame retardants have been found to be effective in many plastics. However, environmental and health concerns have caused halogenated flame retardants to be less desirable for electronic devices, and they are being increasingly regulated.
“A wide variety of flame retardant resin compositions have been developed to ensuring safety against fire, including halogen free flame retardant resin compositions. Generally, halogen free flame resisting resin compositions contain inorganic fillers, such as aluminum hydroxide or magnesium hydroxide. The amount of the inorganic filler required to obtain sufficiently high flame resisting effect is generally 30 to 70% by weight based of the composition.
“However, a synthetic resin composition containing such high contents of inorganic filler generally do not exhibit suitable physical characteristics, such as well-balanced strength, resulting in brittle products with poor processability. Accordingly, there is a need for new halogen-free flame retardants, as well as new halogen-free plastics and resin materials.”
— Dennis Sellers