US2495173A - Noncrystalline synthetic resin holder - Google Patents

Description

Jan. 17, 1950 c. Bl LEAPE NoNcRYsTALLINE SYNTHETIC RESIN' HOLDER Filed June 19, 1947 INVENTOR Char/es B. Leae. M

ATTONEY Patented Jan. 17, 1950 NONCRYSTALLINE SYNTHETIC RESIN HOLDER Charles B. Leape, Pittsburgh, Pa., assigner to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Application J une 19, 1947, Serial No. 755,752

2 Claims. 1

This invention relates to holders for retaining samples of powder gums or the like which are to be subjected to various tests and particularly X-ray diffraction tests.

In performing X-ray diffraction tests, particularly with powders and similar materials that are not in the form of a unitary solid, it is necessary to position the material in such a manner that it is completely bathed in a relatively narrow beam of X-rays. tested and it is necessary to unite the powder with some adhesive material to produce a unitary member. The prior art techniques have been found to be quite cumbersome as Well as time consuming as well as being unreliable at times. In other cases, it has been impossible to test numerous certain organic materials by conventional procedures due to their reactivity and other properties. While it has been suggested that an envelope might be prepared from a resinous material and the powders or crystals be placed within the envelope and thus tested. However all previously known resins appear to have a characteristic X-ray pattern due to a crystalline structure. This creates an interfering X-ray pattern on testing such a combination. Confusion between the interfering X-ray diffraction pattern of the powder being tested and the resin holder thus arises and misleading results may be reported. This is particularly true with numerous resinous materials that may have a strong pattern or a pattern quite similar to that possessed by the material being analyzed or tested.

The present invent'on is based on the discovery of a non-crystalline or isotropic resin. This isotropic resin has been found to be eminently suitable for a holder or envelop-e for samples of powders and the like to be subjected to X-ray diffraction testing.

The object of this invention is to provide a sample holder having substantially no crystalline structure observable on X-ray diffraction tests.

A further object of the invention is to provide an envelope sample holder composed of a polyester-amide resin composition having substantially non-crystallinity observable on X-ray diffraction testing.

Other objects and advantages of vthe invention will in part appear hereinafter and will in part be obvious. For a better understanding of the nature and objects of the invention, reference should be had to the following detailed description and drawing, in which:

Figure 1 is a view in elevation, partly in section.: .of the preparation of holders;

A loose powder cannot be properly l Fig. 2 is a view in elevation, partly in cross section, of a closed end holder;

Fig. 3 is a, View in elevation, partly in cross section, of a tube form of holder; and

Fig. 4 is a view in perspective of a holder prepared by sealing the edges of a sheet of resin.

Referring to Fig. 1 of the drawing, there is illustrated an apparatus for producing holders in the form of thin tubes closed at one end from the isotropic and relatively non-crystalline resinous compositions to be disclosed hereinafter. The tank II) contains the solution I2 of the isotropic resinous composition. A bar I4 containing a number of round ended fingers I6 is located for movement into and out of the composition I2 whereby a film of the composition may be dipcoated on the fingers to a selected depth. A ne capillary bore I8 passing through the center of each of the fingers I6 is connected to a channel 20 which, in turn, is connected by a conduit 22 controlled by valve 24 to a source of compressed air or gas 26.

Upon dipping the lingers I6 one or more times into the composition I2 and drying to evaporate the solvent from the composition, e, resinous coating in the form of a closed end holder 28 is present on the tip of each of the fingers I6. The bar I4 wth the coated fingers may be subjected to heating by infrared radiation or hung in an oven in order to cure the resin partly or entirely to permit the removal of the resinous holders 28 from the lingers. This is accomplished by opening the valve 24 to admit air from the source 26 into the channel 20 and thence to each of the capillary bores I8 thereby blowing 01T the holders 28. The separated holders 28 may be cured at a temperature of 150 C. or higher for a few minutes if insufficiently cured previously. The ngers I6 may be initially coated with a film of a suitable parting compound before dipping in the composition I2 to facilitate 'the easy separation of the resinous holders 28 from the fingers IB. The fingers I6 may be made of metal such as alumi- I num or copper, or from glass or even certain resinous compositions.

The resinous composition l2 is a unique isotropic polyester-amide type product prepared by reacting a combination of unsaturated and saturated dicarboxylic acids or anhydrides of the unsaturated dicarboxylic acids, polyhydric alcohol and aliphatic diamine. The unsaturated dicarboxylic acid is selected from the group consisting of maleic acid, fumarie acid, maleic an- ,hydride and the monomethyl substitution dea dropping funnel.

rivatives for the noncarboxyl hydrogens thereof. Citraconic acid and citraconic anhydride are examples of such monomethyl derivatives. In combination with the unsaturated dibasic acid is a lesser molar amount of saturated aliphatic hydrocarbon dicarboxylic acid, selected from dicarboxylic acids having from 1 to l2 non-carboxyl carbon atoms, and including at least mole-percent of succinic acid. Reacted with the combination of dicarboxylic acids are a diamine selected from the group consisting 'of ethylene diamine and propylene diamine, and a polyhydric alcohol, the major proportion of .which is a glycol. Suitable polyhydric alcohols are ethylene glycol, propylene glycol, diethylene glycol, hexamethylene glycol, glycerol and pentaerythritrol.

In producing the resin, the unsaturated dibasic acid and saturated dibasic acid in an amount totaling from 7.2 to 8.8 moles are reacted with the aliphatic diamine and polyhydric alcohol totaling the same number of moles or witha v molar excess of up to as much as a third more.

In general, the saturated dicarboxylic acid may .be either a single acid or a mixture of several dicarboxylic acids having from 1 to 12 non-carboxyl carbon atoms selected to provide an aver- Vage of from 2 to 31/2 noncarboxyl carbon atoms per dicarboxylic acid molecule. However, at least 25 mole-percent of the saturated dicarboxylic acid should be succinic acid, since succinic acid v`appears to be critical in securing satisfactory enamel coatings.

More specifically, exceptionally good synthetic l resins are prepared from about 4.25 to 5.9 moles of the unsaturated dicarboxylic acid or'anhydride thereof, such as maleic anhydride, and from 2 to 4.8 moles of a saturated dicarboxylic acid of l, which at least 25 mole-percent is succinic acid.

Good results have been obtained with only succinic acid as the saturated dicarboxylic acid.

From 2.1 to 2.65 moles of either-ethylene diamine or propylene diamine or a mixture of both is combined with from 5 to 6.75 moles of a glycol or a f mixture of polyhydric alcohols of which the major proportion is a glycol.

The following example is indicative of a mode of preparation of the synthetic polyester-amide resins of this invention:

' were reacted by placing the rst four ingredients in a reaction vessel equipped with a thermometer,

stirring means, gas inlet tube, an outlet tube for removing water liberated during the reaction, and After the four ingredients had been stirred into a uniform mixture, the

Y ethylene diamine was added to the solution slowly from the dropping funnel with rapid stirring. The rate of addition of the ethylene diamine was so adjusted that approximately ten minutes were required tc add it to the reaction vessel contents. A n exothermic reaction occurred during the addition of the ethylene diamine 1 which caused the temperature to rise from 100 C. to 115 C. After the addition of ethylene dito 60% resin'solids.

vabout 170 .C. to 175 C. At this point, the ball and ring temperature of the resinous reaction product was from 45 C. to 90 C. The reaction was then terminated by diluting the resinous reaction product with a solvent in an amount suiicient to produce a composition having about 50% The relatively concentrated resin solution was then cooled rapidly to room temperature.

Various solvents may be employed for dissolvving the polyester-amide reaction product to produce a solution thereof.

Suitable solvents are diacetone alcohol, cresol, toluene, equal parts of a cresol and ethyl alcohol mixture, Vequal parts of a cresol vand petroleum fraction boiling in a temperature range offrom 50 C. to 75 C., and

`mixtures of cresol with ethyl lactate, solvent naphtha, tetrachloroethane, ethylene dichloride, trichlorbenzene or monochlorotoluene. This list is merely exemplary and not limiting since numerous other organic liquids and various mixtures or organic liquids may be employed as solvents.

The reactants of Example I may be varied from 5 to 5.75 moles of maleic anhydride, from 1.2 to

1.5 moles each of adipic and rsuccinic acids, from `2.1 to 2.65 moles of ethylene diamine and from 5 to 6.75 moles of ethylene glycol, the acids being balanced to produce the same molar total and thediamine and glycol being similarly balanced.

The order of reaction of the ingredients of -Ex- 'ample Iis not particularly critical. For example,

the diamine may be reacted with either of the unsaturated or saturated dibasic acids before combining With the glycol and the other acid. The rate of reaction may be increased or decreased considerably without notably affecting the product. In general, the procedure under Example I gives the best results. Obviously, the end point ofthe reaction may be modified to suit the intended application of the resins. The reaction may be so conducted as to carry the resins to a more advance state of polymerization, or to a lower degree of polymerization for some applications. In these ways, resins of varying degrees of toughness and flexibility may be secured, thus allowing a broad latitude in meeting various requirements.

Example II Moles Fumaric acid 5.34 succinic acid 1.33 Adipic acid 1.33 Ethylene diamine 2.4 v'Ethylene glycol 5.6

The ingredients were reacted as inExample I, the

ifumaric acid'replacing the maleic anhydride in that example.

Thev resinous compositions produced herein have certain highly desirable characteristics.

vX-ray diffraction studies indicate substantially no crystallinity. Films of this resin have been prepared in variouszways and no crystallinity has been found by X-.rayz'diffractionstudies. Even when stretched, no substantial amount of crystallinity or orientation has been found. This indicates a high degree of isotropicity and homoge neity of structure.

Referring to Fig. 2 of the drawing, there is i1- lustrated a greatly enlarged view of one of the holders 28 as prepared in the apparatus of Fig. 1.

-The holder comprises a relatively uniform internal bore terminated by a closure 30 and has an open end 32 for introducing a powdered or other sample into it. The open end may be sealed if desired after the sample has been introduced.

In Fig. 3 of the drawing, there is illustrated a greatly enlarged view of a different form of a tubular holder 40 having open ends 42. 'I'he tubular holder of Fig. 3 is prepared by coating copper wire in the isotropic resinous composition. A suitable diameter for the copper wire is from about 0.25 to 1.0 millimeter. The wire may be much larger or somewhat smaller to suit the size of tubular holder desired. The thickness of the composition on the wire may be approximately 0.010 millimeter after baking in an oven for a few minutes at temperatures of around 350 C.-450 C. to cure the resin to a hard thermoset condition. The wire is then aged in an oven for 36 hours at 150 C. The wire is cut into short lengths and upon jerking these lengths suddenly to elongate the copper about 25% or more, the resinous coating is freed from the copper and can be readily slipped off. Tubes of any suitable length can then be prepared by cutting. The tubes can be filled by tapping the holder against the powdered or crystalline material on a glass plate, inverting and shaking, and repeating to iill the tube up. The ends of the tubes may be sealed with a similar resin or other adhesive material since the ends are not subjected to X-ray beam.

If desired, sheets of the resinous composition may be prepared by flowing a predetermined amount of the resinous composition upon glass plates or upon sheets or blocks of polytetrafluoroethylene and curing them to a thermoset condition whereupon they may be stripped from the base. The sheets may then be cut to selected length and width and, as illustrated in Fig. 4, the edges may be cemented with some of the solution of the resinous composition. In Fig. 4 the holder 50 comprises a sheet 52 with the edges sealed together at 54 with some of the same composition as that from which the sheet 52 is composed. The envelope or holder so prepared may be filled in the usual manner.

It will be apparent that there are numerous other forms of materials that may be prepared from the resinous compositions disclosed herein. Therefore, the above description and drawing are intended only to be exemplary and not exhaustive.

I claim as my invention:

1. A holder suitable for holding samples for X-ray diffraction tests comprising a thin walled cylindrical member having a longitudinal passage for receiving a material, the walls of the cylindrical member being composed of a substantially non-crystalline resin when observed on X-ray diffraction tests, the resin being composed of the heat cured resinous reaction product of from 4.25 to 5.9 moles of an unsaturated acidic compound selected from the group consisting of maleic acid, fumarie acid, maleic anhydride and the monomethyl substitution derivatives for the non-carboxyl hydrogen thereof, from 4.8 to 2 moles of a mixture of saturated hydrocarbon aliphatic dicarboxylic acids having an average of from 2 to 31/2 non-carboxyl carbon atoms per acid molecule selected from the group consisting of saturated aliphatic dicarboxylic acids having from 1 to l2 non-carboxyl carbon atoms, the saturated dicarboxylic aliphatic acids composed of at least 25 mole-percent of succinic acid, the moles of the acidic ingredients totaling from 7.2 to 8.8, from 2.1 to 2.65 moles of aliphatic hydrocarbon primary diamine, the aliphatic diamine having an average of from 2 to 3 carbon atoms per molecule, and from 5 to 6.75 moles of a mixture of aliphatic polyhydric alcohols having no other reactive groups than the hydroxyl groups, the major proportion of the polyhydric alcohol mixture being glycol, the total moles of aliphatic diamine and polyhydric alcohol substantially equal to at least the moles of the acidic ingredients but not in excess of 4/3 of the moles of the latter.

2. A holder suitable for holding samples for X-ray diffraction tests comprising a thin walled cylindrical member having a longitudinal passage for receiving a material, the walls of the cylindrical member being composed of a substantially non-crystalline resin when observed on X-ray diffraction tests, the resin being composed of the heat cured resinous reaction product of from 5 to 5.75 moles of maleic anhydride, from 1.2 to 1.5 moles of succinic acid, from 1.2 to 1.5 moles of adipic acid, the three acidic ingredients totaling substantially 8 moles, from 2.1 to 2.65 moles of ethylene diamine and from 5 to 6.75 moles of ethylene glycol, the ethylene diamine and glycol totaling at least 8 moles.

CHARLES B. LEAPE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,546,349 Hull et al July 14, 1925 2,048,778 Brubaker et al July 28, 1936 2,282,827 Rothrock May 12, 1942 2,285,370 Staelin June 2, 1942 2,424,884 Cook et al July 29, 1947 OTHER REFERENCES Structure of Metals, by C. S. Barrett, published by McGraw-Hill Book Co., New York, 1943, p. 118.

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