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177.1500 Nylon resins.

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[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2006]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR177.1500]

[Page 276-283]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 177_INDIRECT FOOD ADDITIVES: POLYMERS--Table of Contents
 
Subpart B_Substances for Use as Basic Components of Single and Repeated 
                        Use Food Contact Surfaces
 
Sec.  177.1500  Nylon resins.

    The nylon resins listed in paragraph (a) of this section may be 
safely used to produce articles intended for use in processing, 
handling, and packaging food, subject to the provisions of this section:
    (a) The nylon resins are manufactured as described in this paragraph 
so as to meet the specifications prescribed in paragraph (b) of this 
section when tested by the methods described in paragraph (d) of this 
section.
    (1) Nylon 66 resins are manufactured by the condensation of 
hexamethylene-diamine and adipic acid.
    (2) Nylon 610 resins are manufactured by the condensation of 
hexamethylene-diamine and sebacic acid.

[[Page 277]]

    (3) Nylon 66/610 resins are manufactured by the condensation of 
equal-weight mixtures of nylon 66 salts and nylon 610 salts.
    (4) Nylon 6/66 resins manufactured by the condensation and 
polymerization of Nylon 66 salts and epsilon-caprolactam.
    (5) Nylon 11 resins are manufactured by the condensation of 11-
aminoundecanoic acid.
    (6) Nylon 6 resins are manufactured by the polymerization of 
epsilon-caprolactam.
    (7) Nylon 66T resins are manufactured by the condensation of 
hexamethyl-enediamine, adipic acid, and terephthalic acid such that 
composition in terms of ingredients is 43.10.2 
weight percent hexamethyl-enediamine, 35.31.2 
weight percent adipic acid, and 21.61.2 weight 
percent terephthalic acid.
    (8) Nylon 612 resins are manufactured by the condensation of 
hexamethylenediamine and dodecanedioic acid.
    (9) Nylon 12 resins are manufactured by the condensation of omega-
laurolactam.
    (10)(i) Impact modified Nylon MXD-6 resins (CAS Reg. No. 59655-05-9) 
manufactured by the condensation of adipic acid, 1,3-
benzenedimethanamine, and alpha-(3-aminopropyl)-omega-(3-amino-
propoxy)poly- oxyethylene under such conditions that the alpha-(3-amino-
propyl)-omega-(3-aminopropoxy) polyoxyethylene monomer content does not 
exceed 7 percent by weight of the finished resin.
    (ii) Nylon MXD-6 resins (CAS Reg. No. 25718-70-1) manufactured by 
the condensation of adipic acid and 1,3-benzenedimethanamine.
    (11) Nylon 12T resins are manufactured by the condensation of omega-
laurolactam (CAS Reg. No. 0947-04-6), isophthalic acid (CAS Reg. No. 
0121-91-5), and bis(4-amino-3-methylcycl-ohexyl)methane (CAS Reg. No. 
6864-37-5) such that the composition in terms of ingredients is 
34.41.5 weight percent omega-laurolactam, 
26.80.4 weight percent isophthalic acid, and 
38.80.5 weight percent bis(4-amino-3-
methylcyclohexyl)-methane.
    (12) Nylon 6I/6T resins (CAS Reg. No. 25750-23-6) are manufactured 
by the condensation of hexamethylenediamine, terephthalic acid, and 
isophthalic acid such that 65 to 80 percent of the polymer units are 
derived from hexamethylene isophthalamide.
    (13)(i) Nylon 6/12 resins (CAS Reg. No. 25191-04-2) are manufactured 
by the copolymerization of a 1 to 1 ratio by weight of epsilon-
caprolactam and omega-laurolactam.
    (ii) Nylon 6/12 resins (CAS Reg. No. 25191-04-2) are manufactured by 
the copolymerization of a ratio of at least 80 weight percent of 
epsilon-caprolactam and no more than 20 weight percent of omega-
laurolactam.
    (14) Nylon 6/69 resins (CAS Reg. No. 51995-62-1) are manufactured by 
the condensation of 49.5+0.5 weight percent epsilon-caprolactam, 
19.4+0.2 weight percent hexamethylenediamine and 31.2+0.3 weight percent 
azelaic acid.
    (15) Nylon 46 resins (CAS Reg. No. 50327-77-0) are manufactured by 
the condensation of 1,4-butanediamine and adipic acid.
    (16) Nylon resins PA 6-3-T (CAS Registry No. 26246-77-5) are 
manufactured by the condensation of 50 mol percent 1,4-
benzenedicarboxylic acid, dimethyl ester and 50 mol percent of an 
equimolar mixture of 2,2,4-trimethyl-1,6-hexanediamine and 2,4,4-
trimethyl-1,6-hexanediamine.
    (b) Specifications:

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                        Maximum extractable fraction  in
                                                                                                                        selected solvents  (expressed in
                                                      Melting                                                             percent  by weight of resin)
                                         Specific      point       Solubility  in boiling                             ----------------------------------
             Nylon resins                 gravity     (degrees            4.2N HC1            Viscosity No.  (mL/g)               95
                                                    Fahrenheit)                                                                percent   Ethyl
                                                                                                                        Water   ethyl   acetate  Benzene
                                                                                                                               alcohol
--------------------------------------------------------------------------------------------------------------------------------------------------------
1. Nylon 66 resins....................  1.14140 using the      3.0
 specified in 21 CFR 177.1395 of this   minus 110..........   0.007     0.64    0.003        0
 use (excluding bottles) in contact     minus2 [deg]C.
    (2) Melting point. The melting point shall be determined as follows: 
Use a hot-stage apparatus. The use of crossed nicol prisms with a 
microscope hot stage and reading of the thermometer when the 
birefringence disappears increases the accuracy. If the crossed nicol 
apparatus is not available, use the lowest temperature at which the 
sample becomes transparent or the sharp edges or corners of the sample 
become rounded as the melting point. In case of doubt as to the onset of 
melting, the sample is prodded with a sharp instrument. If it sticks to 
the heating block, it is considered to have melted. If the melting point 
is low, dry the sample in an oven at 85 [deg]C for 24 hours in a 
nitrogen atmosphere then repeat the test.
    (3) Solubility in boiling 4.2N HCl. The test shall be run on a 
sample approximately the size of a \1/8\-inch cube in at least 25 
milliliters of 4.2 normal hydrochloric acid.
    (4) Maximum extractable fraction in selected solvents. The procedure 
for determining the maximum extractable fraction of the nylon resins in 
selected solvents is as follows:
    (i) Film should be cut with ordinary scissors into pieces of a 
convenient size such as \1/4\-inch squares, for the extraction tests 
described in this section. The granules of nylon molding powders are in 
the proper form for the extraction tests. Samples of fabricated articles 
such as pipe, fittings, and other similar articles must be cut to 
approximately the size of the molding powder. This can be done 
conveniently by using a small-scale commercial plastics granulator and 
cutting the sample through a screen having \1/4\-inch mesh. Fine 
particles should be separated from the cut resin by screening through a 
20-mesh screen. The material retained on the screen is suitable for the 
extraction tests.
    (ii) The organic solvents must be of American Chemical Society 
analytical reagent grade; distilled water is used. Approximately 30 
grams of the prepared sample is weighed to the nearest milligram. The 
weighed resin is transferred to a 500-milliliter round-bottom flask 
equipped with a reflux condenser. Approximately 300-milliliters of 
solvent is added to the flask and the contents refluxed gently for 8 
hours with a heating mantle. The solvent is then filtered off 
immediately while still hot, using a Buchner funnel approximately 5 
inches in diameter, a suction flask, and a hardened filter paper 
(Whatman No. 50 or equivalent). The paper is wet with the solvent and a 
slight suction applied just before starting the filtration. The resin is 
washed twice with approximately 100-milliliter portions of solvent and 
the combined filtrate and washings are reduced to approximately 25 
milliliters by evaporation at reduced pressure (50 millimeters to 100 
millimeters of mercury, absolute), heating as necessary. The contents of 
the flask are transferred to an evaporation dish

[[Page 283]]

(which has been held in a vacuum desiccator over anhydrous calcium 
sulfate until constant weight has been attained) and carefully 
evaporated to dryness. The weight of the solid residue is determined by 
difference after holding in a vacuum desiccator over anhydrous calcium 
sulfate until constant weight has been attained. The percent of solids 
extracted is calculated by dividing the weight of the solid residue by 
the weight of the sample and multiplying by 100.
    (5) Viscosity number (VN). (i) The viscosity number (VN) for Nylon 
6/12 resin in a 96 percent sulfuric acid solution (5 milligrams resin 
per milliliter) shall be determined at 25 [deg]C (77 [deg]F) by method 
ISO 307-1984(E), ``Plastics-Polyamides-Determination of Viscosity 
Number,'' which is incorporated by reference. Copies are available from 
the Center for Food Safety and Applied Nutrition (HFS-200), Food and 
Drug Administration, 5100 Paint Branch Pkwy., College Park, MD 20740, or 
available for inspection 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.
    (ii) The viscosity number (VN) for Nylon 6/69 and Nylon PA-6-3-T 
resins in a 99 percent cresol solution (5 milligrams resin per 
milliliter) shall be determined at 25 [deg]C (77 [deg]F) by method ISO 
307-1984(E), ``Plastics-Polyamides-Determination of Viscosity Number,'' 
which is incorporated by reference. The availability of this 
incorporation by reference is given in paragraph (d)(5)(i) of this 
section.

[42 FR 14572, Mar. 15, 1977]

    Editorial Note: For Federal Register citations affecting Sec.  
177.1500, see the List of CFR Sections Affected, which appears in the 
Finding Aids section of the printed volume and on GPO Access.





Additives that reference this regulation:


Source: U.S. Code of Federal Regulations - CFR Title 21, Part 177, Section 1500


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