1、MIL-C-5537A 68 9 O6 OL3i46L 6 I - R-57-07 MIL -C -5 537A MILITARY SIFICATION 21MAY 1953 . Superseding MIL*-5537 9 January 1950 CELLULSE ACETATE BUTBUTE This specifiication has been approved by the Departments of the Army, the Navy, and the Air Force. 1. SCOPE 1.1 This specification covers one type a
2、nd grade of cellulose acetate butyrate. In powder or pellet form, it is used in organic pmtective coatings. 2. APPLICABU SPECIFICATIONS, STANDARDS, DRAWINGS, AND PUBLICATIONS 2.1 The following specifications and standard, of the issue in effect on date of invitation for bids, form a part of this spe
3、cification to the extent specified herein; SPECIFICATIONS Federal O-A-51 O-A-3 96 TT-P-41 TT-P-u3 STANDARDS MIL-STD- Acetone Alcohol; Ethyl Paint, Varnish-, Lacquer, and Related Materials; Methods of Inspection, Sampling, and Testing Paint, Varnish, Lacquer, and Related Materials; General Specificat
4、ion for Packaging, Packing, and Marking Marking of Shipments (Copies of specifications, standards, and drawings required by contractors in-connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer,) Provided by IHSNot for
5、ResaleNo reproduction or networking permitted without license from IHS-,-,-3.1 Material.- Cellulose acetate butyrate shall be a product of esterification from newly prepared purified cellulose, No reworked material from other processes shall be employed. 1 3.2 Esterification. - 3.2.1 Acet 1 content.
6、- The acetyl content shall be between 27.0 and 32.0 percent by weight (37ment combined acetic acid). 3.2.2 Butyral content.- The butyral content shall be between 15 and 19 percent by weight (18.6 - 23.6 percent conbined butyric acid). 3.2.3 gdmxyl content.- The free hydroxyl content shall be between
7、 0.8 and 1.8 percent. 3.3 Aciditg.- The acidity shall be less than 0.12 percent calculated as acetic acid. 3.4 Viscosity.- The viscosity of the cellulose acetate butyrate in a 20-percent solution by weight in acetone, conforming to Specification O-A-51, shall be between 10 and 16 seconds. 3.5 Bronzi
8、 ro rties.- A tehicle oontaining 10 percent of cellulose acetate butyrate and- -percen acetone, conforming to Specification O-A-51, by weight, shall exhibit no gelation after standing for 15 hours, when used for the Broning test. - 3.6 Stabilitz.- 3.6.1 Boiling water.- The cellulose acetate butyrate
9、 when boiled in water for 7 hours,.shall not show an increase in acidity of mre than 0.10 percent calculated as acetic acid. 3.6.2 Heat.- The cellulose acetate butyrate shall not darken in spots, mlt, or be any darkerthan a light tan, when heated at 19OoC (374OF) for 1 hour. 3.7 So1ubilitp.- 3.7.1 E
10、thylene dichloride.- A solution containing 12 .parts of cellulose acetate butyrate to 88 parts of ethylene dichloride by weigtil;, shall be clear and smooth after agitation for 16 hours. 3.7.2 Alcohol and acetone.- Cellulose acetate butyrate shall exhibit at least 95 percent solubility *en 1/10 gram
11、 is added to a mixture of 5 ml.of acetone and 3 ml of ethyl alcohol, in accordance with Specification O-A-396, and less than 70 percent solubility when 1/10 gram is added to a mixtwe of 5 ml of acetone and 8 ml of ethyl alcohol,. at a tmperature of 25OC (77F). 3.8 Color.- A solution containing one p
12、art of cellulose acetate butyrate to four i parts acetone by weight shall exhibit a color value less than a standard No. 4 Hazen solution. 3.9 Clarity.- A solution containing one part cellulose acetate butyrate to nine parts acetone by wei percent = combined acetic acid percent x 0.7167 4.3.2.1.1.2
13、Isolation of the l of distilled water which is caught in a 600-ml beaker*, The reaction dope, thinned if necessary with pyridine, is poured slowly into the water with very vigorous stirring. If it is lumpy or hardsthe determination shall be repeated. A solution of 50 ml of acetic anhydride and 950 m
14、l If the water content of the pyridine is greater A standard alkali solution used The apparatus shall consist of an Erlenmeyer 250-ml flask b.3.2.1.2.2 Procedure.- The sample to be tested is thoroughly dried, usually One-gram The flasks shall be fitted with reflux con- Heatirg is continued for a few
15、 moments to complete the decomposition of The condenser is then The precipitate must be soft; fine, and easily penetrable. The solution in the beaker is then titrated with 0.5 N sodium hyroxide to an endpoint preferably determined electrometrically. Aikali is added slowly and carefully with stirring
16、 until the observed EH rises to 9.0, xhich is talcen as the erdpoint. electrometric method shall be used for all reference tests; however, far prodwtion checking a colorimetric mthod may be used. Colorimetric endpoints cannot be located accurately because interfering colors are formed by side reacti
17、ons and are usually accurate only to %.2 percent. A large amount of indicator must be wed to pmduce a color t.0 the second tube 2 ml; etc. One tenth of a gram of cellulose acetate butyrate shall then be added to each of the test tubes, the tubes corked with tin-foiled stoppers, and shaken for 12 hou
18、rs and examined. Five nil of acetone shall be added to each of the rine tubes. To the first tube, 8 , Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-5537A 68 7779706 OLLV627 5 4.3.2.5 Clarity.- Haze value shall be msasured by mans of the absor
19、ption cell and haeeometer as described below. 4.3.2.5.1 Apparatus.- The absorption cell shall be niade of pyrex glass. All the joints shall be fused. 10 mm a.1 nun. The parallelism of the liquid-glass interfaces shall be within 0.025 mm. The flatness of the windows after fusing shall be within SLK w
20、ave lengths. of the faces of each window shall be within 10 minutes. The cell shall be 4l-m outside diameter (appraxhately 38-mm inside diameter). It shall have an open mouth with ground flat glass cover and a flat bottom. The inside length between faces or windaws shall be The parallelism 4.3.2 .s.
21、l.l figure 2. front of a reflector. which is blackened. The base of the cylindrical shield opposite the reflector shall be closed and equipped with a 1-inch circular aperture. ing a similar aperture shall be mounted in front of a photoelectric cell i8 inches from the first aperture. with Viscor filt
22、er. range and an internal resistance of 50 ohms. cell unit shall be mounted in a suitable box finished on the inside in dull black to reduce reflection to a minimum. box lid, also finished in dull black on the inside, shall fit tightly to prevent any external light from reaching the photoelectric ce
23、ll, and th lid shall be closed when making measurements. A 6- or 8-volt storage battery shall be used to operate the lamp. The intensity of the lamp shall be adjustable by means of a rheostat. The battery and meter need not be.attached to the box containing the other elements of the hazeometer. The
24、solution 5s prepared by adding the cellulose acetate butyrate to the acetone and shaking for at least 2 hours on a mechanical shaker. haze measurement shall, be made after removal of the solution from the shaking machine. The solution is poured into the absorption cell and measured within 20 minutes
25、. bubbles shall not be present. so adjusted that a current of 100 microbperes is obtained from the ptiotoelectric cell with no solution in the hazeometer. The absorption cell containing the solution shall be so placed against the lamp shield aperture (aperture B, figure 2) that all the light from th
26、e lam shall pass through the solution. The lamp shield apertures should be covered with lx-inch thick felt washers in order that the window .cannot be scratched on the shield. by passage through the absorption cell will enter the photoelectric cell aperture (aperture A, figure 2). aperture A which.
27、is scattered when the absorption cell is placed at posibion aperture B. It is calculated as follows: Hazeometer .- This instrument is illustrated diagrammatically in The light source shall consist of a 6-volt automobile type bulb.mounted in It shall be placed within a cylindrical shield, the inside
28、of A circular blackened disk contain- The photoelectric cell shall be the Weston phototronic cell, type I The cell shall be connected to an ammeter with a 100-microampere The light source unit and the photoelectric If the apparatus is not set up in a dark room, then the 4.3.2.5.2 Procedure.- The Air
29、 The intensity of the lamp of the hazeometer shall be Only that portion of the light which has not been caused to deviate from its path Tne haze value is the percentage of the total light transmitted at position where ilan and aperture A and aperture B, respectively. readings. One-half of the readin
30、gs shall be made with one window of the absorption cell facing the photoelectric cell, and the other half shall be made with the opposite window facing the photoelectric cell. tared dish (fitted with a lid) and dried in an oven for 2 hours at 100 to 105C (212 to 221F) Tile dish shall be removed from
31、 the oven, covered and cooled in a desiccator, and weighed, and the misture loss calculated. represent readings obtained with the absorption cell in positions itAn and “bti shall be averages of six or more 4.3.2.6 Moisture .- Five grams of the sample shall be accurately weiiouc rejection and the act
32、ion taken to correct the defects found in the original shall be furnished the Government Inspector. after retest shall not be resubmitted without the specific approval of the procuring activity . Material rejected 5. PREWIRATION FOR DELIVERY 5.1 Application.- The requirements specified herein apply
33、only to direct purchases by or direct shipments to the ,Government. 5.2 Packaging and packing.- The packaging and packing for shipment shall be in accordance with Specification TT-P-l.43. marked in accordance with Standard MILSTD-129. 5.3 Marking of shipments.- Cellulose Acetate Butate, Specificatio
34、n MIL-C-5537A Interior packages and shipping containers shall be The nomenclature shall be as follows: 6. NOTE 6.1 Intended use .- Cellulose acetate butyrate covered by this specification is intended for use in the manufacture of organic protective coatings used on aircraft. 6.2 urdering data.- Requ
35、isitions, contracts, and orders shall state the size of the containers in which the cellulose acetate butyrate is to be furnished arui whether oveweas packing is required (see Section 5). The material shall be purchased on a dry basis, the unit being 1 pound. 6.3 Superseding data .- This specificati
36、on supersedes Specification MIL-C-5537 whioh was the number assigned by cover sheet to Specification AN-C-69. NOTICE: When Government drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement operation, the United State
37、s Government thereby incurs no responsibility nor any obligation whatsoever; and the fact that the Government may have formulated, furnished, or in any way supplied the saiddrawings, specifications, or other data, is not to be regarded by implication or otherwise as in any manner licensing the holde
38、r or any other person or corporation, or cunveying any rights or permission to manufacture, use, or sell any patented invention that may in any way be related thereto. Custodians: Nary - Bureau of Aernautics Air Fome 1, - rdnance corps Other interest: Arniy - dQ Navy - Y , Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
