§177.1556 聚芳基醚酮树脂(Polyaryletherketone resins)

    　　§177.1556 Polyaryletherketone resins.


　　     The poly（oxy-1,4-phenylenecarbonyl-1,4-phenyleneoxy-1,4-phenylenecarbonyl-1,4-phenylenecarbonyl-1,4-phenylene） resins （CAS Reg. No. 55088-54-5 and CAS Reg. No. 60015-05-6 and commonly referred to as polyaryletherketone resins） identified in paragraph （a） of this section may be safely used as articles or components of articles intended for repeated use in contact with food, subject to the provisions of this section.

　　（a） Identity. Polyaryletherketone resins consist of basic resins produced by reacting 4,4′-diphenoxy benzophenone and terephthaloyl dichloride in such a way that the finished resins have a minimum weight average molecular weight of 20,000 grams per mole, as determined by light scattering measurements in sulfuric acid at room temperature.

　　（b） Optional adjuvant substances. The basic polyaryletherketone resins identified in paragraph （a） of this section may contain optional adjuvant substances required in the production of such basic resins. These adjuvants may include substances used in accordance with § 174.5 of this chapter and the following:

　　（1） Benzoyl chloride, poly（tetrafluoro ethylene）.

　　（2） [Reserved]

　　（c） Extractive limitations. The finished food-contact article yields net total extractives in each extracting solvent not to exceed 0.052 milligram per square inch （corresponding to 0.008 milligram per square centimeter） of food-contact surface, when extracted at reflux temperature for 2 hours with the following solvents: Distilled water, 50 percent （by volume） ethyl alcohol in distilled water, 3 percent acetic acid （by weight） in distilled water, and n -heptane.

　　（d） In testing the finished food-contact article made of polyaryletherketone resin, use a separate test sample for each required extracting solvent.

　　　　[61 FR 42381, Aug. 15, 1996]