See also A., July, 735, Constituents of guaiacum resin. 749, Resins of Manila elem i.
Pa t e n t s.
Manufacture of [fine-textured] lithopone. Litho- pone pigm ent suitable for flat wall paints and enam els. M. L. Ha n a h a n, Assr. to Kre b s Pig m en t
& Co lor Conr. (U.S.P. 1,826,131—2, 6.10.31. Appl., [a] 24.1.27, [b] 7.3.27).*—(a) A slurry of 1 pt. of calcined lithopone in, e.g.,2 0 pts. of dil. aq. Na2Si03, p a <£ 5-5 (preferably 9-0), is passed up an elutriator at a rate of
< 1 2 ft. per hr. ; the finer particles are recovered from the overflow for use as a pigment and the sediment is, e.g., returned for grinding, (b) The slurry flows through the elutriator at a rate of 6 in. — 6 ft. per hr., and the sediment is used for the manufacture of flat wall paints
and enamels. L. A. C.
Light-resistant lithopone. J. A. Sin g jia s t e r and H. S. C o lt o n , Assrs. to K r e b s P ig m e n t & C o l o r C o rp . (U.S.P. 1,826,153, 6.10.31. Appl., 7.2.29).—V , Cr, W , or U (2—5 mg./100 g.) is incorporated with lithopone, preferably by adding a sol. salt of the metal to the Zn liquor before pptn. or to the freshly pptd. lithopone.
L. A. C.
D yeing transfer and transfer in k . W . S. L a w r e n c e , Asst, to K a u m a g r a p h Co. (U.S.P. 1,827,591, 13.10.31. Appl., 14.4.28).—The ink comprises a colour
British C h e m ic a l A b s tr a c ts —B .
Cl. X III.— Pa i n t s ; Pio m k n t s ; Va k n i s h e s ; Re s i n s. 7 3 7
lake produced in situ, e.g., by the interaction of methyl
ene-blue, tannic acid, and ZnCl2, dispersed in a resinous (preferably resorcinol-CH20) condensation product decomposable by the steam liberated when the transfer is pressed by a hot iron on to a damp cloth ; gum arabic, corn starch, etc. may also be present. L. A. C.
P reparation of coating com position. C. R. E.
Merkle, Assr. to E. I. Du Pont d e Nem ours & Co.
(U.S.P. 1,829,999, 3.11.31. Appl., 16.1.28).—Positive oxidation catalysts, e.g., Pb, Mn, and oxidation inhibi
tors, e.g., thymol, eugenol (for air-drying materials), quinol, a-naphthol (for baking materials), are incor
porated in drying oil compositions in such proportions as prevent their oxidation (“ skinning,” “ fattening ”) m bulk without materially retarding their normal drying
rate in thin films. S. S. W.
M anufacture of liquid coating com position.
J. E. Booge, Assr. to E. I. Du Pontd e Nem ours & Co.
(U.S.P. 1,825,935, 6.10.31. Appl., 20.11.25).—40—640 Pts. of one or more drying oils, blown with 0 2-containing gas until the I val. is 125—140 and viscosity about 1300 centipoiscs at 25°, are mixed with 100 pts. of nitro
cellulose (16-oz. solution of which in EtOAc has viscosity 20—280 centipoises at 25°) and suitable solvents.
S. S. W.
V arnishing. Dr. A. Wacker Ge s. f. Ei.ek tr o-
chem. In d. G.m.b.H. (B.P. 372,385, 6.1.31. Ger., 6.1.30).—An artificial resin, e.g., polyvinyl acetate, or a drying oil in the form of an aq. dispersion free from solvents and emulsifying agents is applied (preferably by spraying with preheated air) to an unheated article.
S. S. W.
M anufacture of conversion products of colophony.
A. Ca k pm a e l. From I. G. Fa r b e n in d. A.-G. (B.P.
372,402, 7.5.31).—Colophony is heated at < 300° in the presence of a hydrosilicate of large surface, e.g., fuller’s earth, activated by a halogen acid, e.g., IIC l, to give pale, neutral oils or solid resins of reduced acidity and giving negative Liebermann-Storch reaction. S. S. W.
P lastic from n a tu ra l re sin , phenol, aldehyde, and alkali. I. S. Me l l a n o f f, Assr. to Ke m ik a x, In c. (U.S.P.
1,804,379, 5.5.31. Appl., 3.7.28).—Fusible or infusible plastic resins are produced by the reaction (at about 70°) between rosin (or other resin, 2 pts.), an aldehyde (CH2 0 , 2 0 pts.), a phenol (20 pts.), and an alkali (aq.
NHg, 2 pts.). Treatment of rosin with, e.g., aq. NBT3, or dissolution of it in PhOII may be performed as a first
step. E. L.
Manufacture of synthetic resins. W. W. Tr ig g s. From Toledo Sy n t h e t ic Prod u cts, In c. (B .P . 373,184, 10.2.31).—2 mols. of CII20 and 1 mol. of urea are con
densed at room temp, in aq. solution, with or without the addition of fillers. The dried product is ground with a CH20-fixing agent (e.g., urea, thiourea) so that the final ratio of CH20 to urea plus fixing agent is between 1-75 : 1 and 1 -5 :1 . I f no fillers are used a phenol-aldehyde or glyptal resin etc., with an org. acid, is advantageously incorporated before the drying
process. E. L.
Manufacture of furfuraldehyde-urea resin. E. E.
Novotny and W. W. John son, Assts. to J . S, Sto kes
(U.S.P. 1,827,824, 20.10.31. Appl., 1.10.24).—Urea and furfuraldehyde or similar products are heated together at < 105° in the presence of a (preferably basic) catalyst, e.g., aq. NH3, KOII, Na2C03, and the potentially reactive fusible condensation product is rendered hard and infusible by further heating with or without a CH2-containing hardening agent. Modifying agents, e.g., tung oil, lanolin, camphor, and fillers, e.g., asbestos,
may be incorporated. S. S. W.
Manufacture of an ester gum . L. N. Be n t and A. C. Jo hnston, Assrs. to He r c u l e s Po w d e rCo. (U .S .P . 1,820,265, 25.8.31. Appl., 24.11.28).—Ester products yielding quick-drying, hard, but elastic films are obtained from abietic acid or materials containing it, such as gum or wood resin, by heating with a higher alcohol, e.g., pentaerythritol, erythritol, or enneaheptitol, at 260—
280° in a current of C 02 and if necessary in presence of a catalyst, e.g., Zn powder or B 20 3. J . H . L.
Production of plastic m asses. 0. Ne u s s (B.P.
372,847, 19.2.31).—CII20 ( 6 6 pts.) is condensed in aq.
solution with urea ( 1 0 0 pts.) in the presence of acid con
densation agents, but without application of heat, and the chalky powder produced is compressed under heat (at about 130°) to yield translucent horny masses.
E. L.
Manufacture of artificial m asses. “ Ko l l o id-
c h e m ie ” St u d ie n g e s.m.b.H ., J. B. Ca r pzo w, R . Len z-
mann, and M. Mar ch (B.P. 372,917, 17.4,31).—Salt- or fresh-H20 mud, in the moist state or after drying in the absence of air, is incorporated with org. colloids (e.g., natural or artificial resins, albuminous m aterial);
hardening agents, vulcanisers, plasticisers, finely-divided metals, etc. may also be added. L . A. C.
Making of sound records. St e a t it-Ma g n e sia
A.-G. (B.P. 373,925, 2.11.31. Ger., 1.11.30).—The recording layer, which is hardened by heat (but without the application of pressure) before and after the record
ing, consists of an artificial (PhOH-urea) resin with
2 0% of inorg. and org. fillers, preferably in colloidal form, such as kaolin, steatite, or graphite, with an equal amount of, e.g., nitrocellulose or gelatin dissolved in
glycerin. E. L.
Production of water-insoluble, petroleum-soluble carboxylic acids, and product thereof. A. W.
Bu r w e l l, A ssr. to Alox Ch e m. Co r p. (U.S.P. 1,828,356, 20.10.31. Appl., 20.12.26).—A petroleum oil distillate having d16 1-42—1-49, e.g., kerosene, is oxidised in the presence of a catalyst (e.g., Mn oleate) by a stream of air at 135—140° under 150—350 Ib./sq. in. pressure.
The acidic products (about 20%) are washed out with alkali, recovered from the soaps by acidification, and distilled in vac. before use as softening agents for nitro
cellulose (leather) lacquers ; 70—80% or more of the
softener can be incorporated. E. L.
[Resinous] cem ent for floor-covering com posi
tions [linoleum ]. H. D. Ga r d n e r (U.S.P. 1,831,707, 10.11.31. Appl., 14.5.30).—The addition of chlorinated Ph2 to the oily and resinous binders used in making
linoleum is claimed. A. R. P.
Manufacture of re-entrant objects from m oulding material containing or consisting of synthetic resin
B r itis h C h e m ic a l A b s tr a c ts —B .
7 3 8 C l . XIV.— In d i a- Ru b b e r ; Gu t t a- Pe r c h a.
and the like. N. V. Ph il ip s’ Gl o e il a m pe n fa b r. (B .P . 375,513, 1.6.31. Holl., 31.5.30).
Manufacture of moulded inlaid linoleum. Arm
strong Cork Co., Assecs. of C. We b e r (B.P. 375,245, 29.2.32. U.S., 13.4.31).
Linoleum. Ryl a n d s & So n s, Lt d. (Dacca Tw is t
Co.), a n d A. Po l l it t (B .P . 372,962, 29.5.31).
Cellulosic com positions.—See V. Safety glass.—
See VIII. Resinous insulation.—See XI. Oil com position.—See XII. Treatment of rubber.-—
See XIV.
X IV .— IN D IA -R U B B E R ; G U T T A -P E R C H A . Autoxidation of caoutchouc and the associated catalytic phenomena. C. H. Du f r a is s e and N.
Drisch (Rev. Gen. Caoutchouc, Oct., 1931, p. 39;
Gummi-Ztg., 1932, 46, 1129).—By exposure of samples of rubber to 0 2 and observation of the initial rate of absorption it is shown th at the cryst. material (O'5%) in the COMe2-extraetable constituents of the rubber has no protective action, whereas the resinous constituents (1-8%) are protective. Unextracted raw rubber shows no signs of oxidation in 5 months in the dark, and even at 130° oxidation is not evident under 9 hr. and the return of the extract to C0Me2-extracted rubber restores substantially the whole of the resistance to 0 2. The antioxidant properties of raw rubber do not disappear entirely on vulcanisation; extraction with COMe2 increases the sensitiveness to 0 2, but return of the extract to the rubber does not have as great an effect as with raw rubber. Autoxidation in vulcanised rubber is therefore probably different in character from th at in raw rubber. The COMe2-sol. material of rubber is also an antioxygen for other substances, e.g..
limonene, pinene and PhCHO. Presence of free S in unvulcanised rubber has no appreciable influence on the rate of autoxidation ; the addition of diphenylguanidine to vulcanised rubber is also substantially without influence, but mercaptobenzthiazole, tctramethylthiuram disulphide, and ethylideneanilinc arc slightly protective.
In low concns. in vulcanised rubber quinol and phenyl- j3-naphthylamine are more effective antioxidants than aldol-a-naphthylamine and m-tolylenediamine. I t is remarkable th at Cu acetylacetonate, w'hicli notably accelerates the oxidation of rubber, is a strong anti-^
oxidant for limonene. D. F. T.
Polvm erides and polym erisation. VI. Vulcan
isation of m ethyl-rubber. G. S. Wh it b yand M, Katz
(Canad. J. Res., 1932, 6, 398—408; cf. A., 1932, 496).
—Vulcanisation of accelerated gum stocks (containing 3% S) of Me-rubber (A., 1932, 361), obtained by poly
merisation of Py-dimethylbutadiene a t room temp, and a t 45°, gives products either weaker or less extensible than those from natural rubber. The strength of the synthetic rubbers is increased (to about i th a t of natural rubber) by incorporating C black (25 pts.) with the stock. The synthetic rubbers are much more sensitive to temp, changes than is natural rubber.
II. B.
Colloidal solutions of rubber. I. Influence of coagulating agents on the solutions. II. Action of coagulating agents and influence of temperature
on the solvated particles of rubber. J. Ka w a m u r a
and K. T a n a k a (J. Soc. Chem. Ind., Japan, 1932, 35, 186—188 b , 188—191 b ).—I. Addition of 10% of COMe, or EtOH to solutions of rubber in CC14, benzine, CcH6, etc. markedly reduces the viscosity, and rise of temp, causes a still further fall except for C6H6-EtO H and xylene-EtOH solutions. If more than a certain pro
portion of EtOH or COMe2 is added, however, rise of temp, produces an increase of viscosity in all cases.
II. The relative viscosities a t 25° and 50° of 0-25%
solutions of rubber in xylene and in mixtures of xylene with Me, Et, Bu", and Bu^ alcohols, and the quantities of these alcohols and COMe2 necessary to coagulatc a CgHg solution of rubber at 25° and 50° have been determined. The action of a coagulant is discussed on the assumption of a statistical distribution of the colloidal particles in the original solution and of a desolvating action of the coagulant ; the latter action increases with increase of concn., but diminishes with
rise of temp. II. F. G.
Rubber for equipment construction. H. E.
F r i t z and J. R . H o o v e r (Chem. and Met. Eng., 1932, 3 9 , 263—265).—A list of substances which do not act
on rubber is given. D . K . M.
Pa t e n t s.
Production of concentrated india-rubber latex.
Du n lo p Ru b b e r Co., Lt d., Ano de Ru b b e r Co., Lt d., and D . F . Tw is s (B.P. 372,836, 19.2.31).—Centrifugally conc. latex preserved with NH3 (after further concn., if desired) is de-ammoniated by the addition of caustic alkali, soap, or other alkali derivative of a colloidal substance and heating under such conditions th at concn.
is not effected. D . F . T .
Thickening and stabilising [rubber] latex. M. C.
Te a g u e, Assr to Am e r. Ru b b e r Co. (U.S.P. 1,826,192, 6.10.31. Appl., 9.6.24).—Latex is thickened and stabil
ised without coagulation or substantial modification of its protein content and without imparting undesirable properties‘to the finished product, by the addition of a suitable metallic compound, e.g., PbS20 3, and/or a saponaceous substance such as saponin. These reagents affect mainly the sol. non-protein constituents of the latex. Latex containing 30% of rubber, and also compounding ingredients, in the course of a few hr.
becomes converted into a paste which can be con
veniently handled with a trowel. D . F . T.
Manufacture of rubber com positions. Dun lo p
Ru b b e r Co., Lt d., Anode Ru b b e r Co., Lt d., E. A.
Mu r p h y, and D . F . Twiss (B.P. 373,262, 20.2.31).—
Granular ppts. are obtained from aq. dispersions of rubber by pptg. in situ one or more compounding ingredients. These are formed by introducing one or more H20-sol. reagents having normally no coagulating effect, e.g., carbonates, sulphates, or silicates of the alkali metals or NH4, and adding one or more H20-sol.
précipitants, e.g., salts of Mg, A l, etc. The pptn., which is effected in the presence of a relatively large proportion of H20 , may be followed by the addition of reagents capable of giving a further ppt. with the sol. product of the first reaction. The slurry-like products can be freed from sol. réaction products by filtration or washing.
D. F. T.
B ritish C h e m ic a l A b s tr a c ts — B .
Cl. XIV.— Ik d i a- Ru b b k b ; Gu t t a- Pe r c h a. 739
Treatment of rubber. A. Da v ie s (B.P. 373,228, 20.2.31. Cf. B.P. 360,852; B., 1932, 237).—Rubber is heated at 280—300°, preferably after masticating, with the addition of a catalyst, e.g., Mg, and with injection of air, so long th at the initial liquid product becomes increasingly more viscous and a hard friable resin-like material is finally obtained. This product is mouldable and can be used in lacquers. D. F. T.
Manufacture of rubber com positions. Dunlop
Rub ber Co., Lt d., Anode Ru b b e r Co., Lt d., E . A.
Mu r p h y, a n d A. Niv e n (B .P . 373,222, 20.2.31).—
M aterials su c h as le a th e r fibre, asb e sto s fib re , w ood flour, a b ra s iv e s, o r c o rk a re b o n d e d b y m ix in g w ith a g ra n u la r d isp e rsio n of c o m p o u n d e d r u b b e r p p t. (cf.
preceding a b s tr a c t) o r w ith th e la te x fro m w h ich su c h a p p t. is su b s e q u e n tly fo rm e d ; th e m ix tu re s a re th e n c o n so lid a te d a n d s h a p e d , e.g.,b y filtra tio n . D . F. T.
Manufacture of goods of rubber or sim ilar material. Dun lo p Ru bb er Co., Lt d., Anode Rubber
Co., Lt d., and E. A. Mu r p h y (B.P. 373,223 and 373,263, 20.2.31).—(a) Articles consisting of two portions respectively with and without fibrous constituents are made by forming two distinct granular rubber slurries (cf. preceding abstracts), only one of which contains fibrous material, and thereafter consolidating, by a filtration process, superposed layers of the 2 slurries.
(b) Thermoplastic materials, e.g., carnauba wax, synthetic resins, or shellac, are incorporated, with or without fibrous additions, in a dispersion of a granular ppt. of rubber, and the mixtures can be applied to the pro
duction of material having the physical properties of leather or of gutta-percha. D. F. T.
Manufacture of rubber articles [with high flexing capacity]. Nauga tuck Chem. Co., Assees. of W. A.
Gibbo ns (B.P. 373,278, 23.2.31. U.S., 8.3.30).—The flexing resistance of vulcanised rubber products embody
ing fabric, especially such as contain sprayed rubber or alkali reclaim, is greatly increased by incorporating before vulcanisation a small proportion of acid, e.g., H3P 04 and/or picric acid, together witlf a C02H-free OH-derivative of C6H6, e.g., cresol. D. F. T.
Prevention of [rubber] water-bag deterioration.
E. T . Ha n d l e y, Assr. to Fir e s t o n e Tir e & Ru b b e r Co. (U.S.P. 1,830,465, 3.11.31. Appl., 31.3.30. Renewed 26.5.31).—The rubber “ bags,” filled with hot H 20 under pressure, used inside rubber tyres during vul
canisation in order to assist this process and also to press the tyre into effective contact with the mould, undergo rapid internal deterioration on account of free 02 dissolved in the II20. Addition of Na2S03 to this H20 substantially prevents this internal oxidation.
D. F. T.
Composition of m atter [containing balata] and its preparation. C. Ma r t e l l, Assr. to We s t e r n
El e c t r ic Co. (U.S.P. 1,829,997—8, 3.11.31. Appl., 27.9.28).—(a) Insulating material to resist the influence of humidity, especially for submarine cables, is prepared by mixing approx. equal proportions of deproteinised rubber, e.g., from heat-treated latex, and balata (prefer
ably deresinated) ; the product has a lower dielectric const, than gutta-percha and is not substantially affected by immersion in H ,0 for 200 days, (b) The washed
mixture from (a) is uniformly blended with a commercial wax, e.g., 50 wt.-% of montan wax, and further refined.
D. F. T.
Covering of wire, thread-like or filam entary m aterial, etc. with india-rubber, gutta-percha, balata, etc. Du n l o p Ru b b e r Co., Lt d., Anode
Rub b erCo., Lt d., F. I I . La n e, E. W. Ma d g e, and E. A.
Mu r p h y (B.P. 373,141,16.2.31. Addn. to B.P. 291,485 ; B., 1928, 616).—The wire (etc.) emerging from the bath of conc. and/or compounded latex bears a coating of the creamy fluid which is then coagulated by treatment with a liquid or gaseous coagulant or dehydrating and setting agent, e.g., with a current of vapour of AcOH or HCOzH. Apparatus is described. D . F. T.
Manufacture of vulcanised rubber. Du n lo p
Ru b b e r Co., Lt d., D . F. Tw is s, and F. A. Jones (B.P.
372,623, 14.7.31. Cf. B.P. 353,871 ; B., 1931, 1021).—
T he metallic salts (group 116) derived from the reaction products of accelerators of the mercaptobenzthiazole, dithiocarbamate, or alkylxanthate type and a mono- halogenoacetic acid, e.g., Zn 2-bcnzthiazylthioacetate, are employed to expedite vulcanisation. D . F. T .
Vulcanisation of rubber and sim ilar m aterials.
L . Me l l e r s h- Jackson. From Naugatuck Ch e m, Co.
(B.P. 372,328, 2.1.31).—Org. accelerators, e.g., heptalde- hydeaniline, which are not inactivated by N H 3, when used for vulcanisation in the presence of air and NH3 give products with higher tensile strength and better ageing properties than when air alone is used. The air-NH3 atm. may be under increased pressure.
D. F. T.
Production of [adhesive] com positions of or con
taining rubber. Dunlop Rubber Co., Ltd., Anode Rubber Co., Ltd., E. A. Murphy, F. T. Pu r k is, and D . F. Tw iss (B.P. 372,775—6, 11.2.31).— A n adhesive, suitable for atta c h in g fibrous surfaces (leather etc.) to vulcanised rubber, is obtained b y m ixing an aq. disper
sion of rubber, such as latex , ( a ) w ith a n aq. dispersion of a rubber solvent, e.g.,coal-tar n a p h th a , in th e presence of one or m ore destabilising ag en ts such as E tO H , C0M e2, or ZnO u nder such conditions th a t no coagula
tio n results ; o r (b) w'ith a ru b b er solvent or aq. disper
sion thereof an d subsequently inducing coagulation by th e addition of a suitable p rec ip ita n t, e.g., MeOH or COMea, o r m ixtures of these w ith one a n o th er or w ith o th e r liquids such as CC14, so th a t th e aq. m edium becomes th e disperse phase an d the ru b b er and solvent
form th e continuous phase. D. F. T.
Reclaim ing w aste [vulcanised] rubber and pro
duct of sam e. W. B. Pr a t t, Assr. to Dis p e r s io n s
Pr o c ess, In c. (U.S.P. 1,826,091, 6.10.31. Appl., 17.2.26).—The disintegrated scrap is agitated with hot H20, e.g., for | hr., a softener or plasticiser, such as rosin oil, is added to the soaked material, and the mixture is kneaded at above 1 0 0°, e.g., for 1—5 hr., until a smooth plastic mass is obtained containing little H20. A hydrophilic colloid is then kneaded into the mass and H20 is gradually added until a change of phase occurs and a butter-like dispersion is finally obtained in which the rubber is present in the form of globules in a con
tinuous medium of H20. The rubber, recoverable by coagulation or evaporation, has greater strength and
aa
B r itis h C h e m ic a l A b s tr a c ts—B .
740 Cl. XV.— Le a t h e r; Gl u e.
elasticity and much finer texture than ordinary reclaimed rubber. If desired, reagents assisting the removal of S from the vulcanised rubber, e.g., H2C20 4, may be introduced into the process at the first stage. I). F. T.
Surface coatings of soft to hard rubber or the like. M. Wil d e r n a n (B.P. 374,842, 2.3.31).
Manufacture of rubber filam ents. Re v e r e
Ru b b e rCo., Assees. of E. Hazell(B.P. 375,244, 29.2.32.
U.S., 11.3.31).
Flame-proofing.—See VII. Therm oplastic- bonded abrasives.—See VIII. Insulating m aterials.
—See XI.
X V — L E A T H E R ; G LU E.
Structure of collagen. J. Be e k, t o n. (Bur. Stand.
J. Res., 1932, 8 , 549—553).—The ratios (/), no. of g.-atoms of Cl/no. of g.-atoms of N, in a sample of collagen (N 17-8, ash 0-0 2, Cl 0-02%) after treatment with gaseous IiCl under varying conditions (in which physical absorption is negligible), have been determined by dissolution in H 20 and titration of the Cl with AgN03, using (NH4)3As04 as an indicator. Thence the mean val. of /„, the smallest fraction of the N found to react, is 0 -02638, whence the no. of N atoms in the unit of collagen structure is l/ / 0 = 38 or a multiple thereof, the corresponding no. of C atoms being 126. This result is in harmony with those obtained by Thomas and Kelly (B., 1928, 581) by reaction of collagen with Cr and Fe salts, and suggests th at collagen is a chemical individual. Similar results with gelatin agree with Belden’s work (A., 1931, 1125). J. W. B .
Combination of collagen with dyes. II. G. A.
Bravoand F, Baldracco (Boll. UfT. Staz. sperim. Ind.
Pelli, 1932, 10, 143—154; cf. B ., 1931, 1065).—Further experiments with other dyes confirm the view that the reaction between collagen and dye is not entirely adsorptive, but yields a true chemical compound.
Under conditions which would affect the result some
what, the combining wt. of collagen is found to be about
1104. T. H. P.
Structural changes in collagen hide fibres caused by electrolytes, bating, and tanning solutions.
J. A. Jovanovtts and A. Aloe (Collegium, 1932, 215—
231).—Fibres are contracted by the action of H2S 04, min. length being given by 0-01A-acid. Collagen fibres were of 3 kinds, viz., 0-02—0-04, 0-04—0-06, and 0-06—0-08 mm. in chain. The fibres were smooth and some of them spiral-shaped; they were non-homogeneous, consisting of fibrils which have a diam. 1 p when swollen in 5iV-KCNS and pre-tanned with a 2% quebracho solution. Without such treatment they were scarcely recognisable and had a diam. 0-1—0-2 p. They are unaffected by H 20 at 60°, but contracted at 65—68°
and lost 70—75% of their length in a few seconds at 75°. Max. shrinkages (%) in length of 14, 15, 33, and 38 were obtained by immersing the fibres in NaOH, H2S 04, HC1, and AcOH, respectively, and the original length was restored on immersing the treated fibres in H20, but the action of A-NaOH was irreversible. The fibres were unaffected by solutions of pa 4— 1 1 and by A'-KCNS and -KI, but were irreversibly shrunken to 27%
of their original length by 5V-KCNS or -KI, in which
state they assumed a plaited appearance with pronounced spiral markings. The fibrils were split up. The bating process was speeded up by pretreatment of the fibres
state they assumed a plaited appearance with pronounced spiral markings. The fibrils were split up. The bating process was speeded up by pretreatment of the fibres