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:
(2)
Substances the use of which is permitted under applicable regulations in this part, prior sanctions, or approvals.
| 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. |
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| Sodium hydrosulfide | |
| Sodium polysulfide | |
| β,β′,γ,γ′-Tetrachloro normal propyl ether | Cross-linking agent. |
| Titanium dioxide | |
| Toluene | Solvent. |
| Trichloroethane | Cross-linking agent. |
| 1,2,3-Trichloropropane | Do. |
| Urea-formaldehyde resins | |
| Xylene | Solvent. |
(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.