§177.1650 Polysulfide polymer-polyepoxy resins.

　　 Polysulfide polymer-polyepoxy res- ins may be safely used as the food-contact surface of articles intended for packaging, transporting, holding, or otherwise contacting dry food, in accordance with the following prescribed conditions:

　　（a） Polysulfide polymer-polyepoxy resins are the reaction products of liquid polysulfide polymers and polyfunctional epoxide resins, cured with the aid of tri（dimethylaminomethyl） phenol, to which have been added certain optional substances to impart desired technological properties to the resins. Subject to any limitations prescribed in this section, the optional substances may include:

　　（1） Substances generally recognized as safe in food and food packaging.

　　（2） Substances the use of which is permitted under applicable regulations in this part, prior sanctions, or approvals.

　　（3） Substances named in this subparagraph and further identified as required:

List of substances	Limitations
Bis(2-chloroethyl) formal
Bis(dichloropropyl) formal	Cross-linking agent.
Butyl alcohol	Solvent.
Carbon black (channel process)
Chlorinated paraffins	Cross-linking agent.
Epoxidized linseed oil
Epoxidized soybean oil
Epoxy resins (as listed in § 175.300(b)(3)(viii) (a) of this chapter).
Ethylene glycol monobutyl ether	Solvent.
Magnesium chloride
Methyl isobutyl ketone	Solvent.
Naphthalene sulfonic acid-formaldehyde condensate, sodium salt
Sodium dibutyl naphthalene sulfonate	Wetting agent.
Code of Federal Regulations 318
Sodium hydrosulfide
Sodium polysulfide
β,β′,γ,γ′-Tetrachloro normal propyl ether
Titanium dioxide	Cross-linking agent.
Toluene
Trichloroethane	Solvent.
1,2,3-Trichloropropane	Do.
Urea-formaldehyde resins
Xylene	Solvent.

　　（b） The resins are used as the food-contact surface for dry food.

　　（c） An appropriate sample of the finished resin in the form in which it contacts food, when subjected to ASTM method D968-81, “Standard Test Methods for Abrasion Resistance of Organic Coatings by the Falling Abrasive Tester,” which is incorporated by reference （Copies may be obtained from the American Society for Testing Materials, 100 Barr Harbor Dr., West Conshohocken, Philadelphia, PA 19428-2959, or may be examined at the National Archives and Records Administration （NARA）. For information on the availability of this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html. ）, using No. 50 Emery abrasive in lieu of Ottawa sand, shall exhibit and abrasion coefficient of not less than 20 liters per mil of film thickness.

　　　　[42 FR 14572, Mar. 15, 1977, as amended at 49 FR 10110, Mar. 19, 1984]

§177.1650 多硫化物聚合物/聚环氧树脂(Polysulfide polymer-polyepoxy resins)