In this paper, fine structures of cellulose gels coagulated freely in a single-bath such as H₂SO₄ or H₂SO₄ Na₂SO₄ baths, were investigated. Effects of bath composition, temperatue, acid-alkali ratio and degree of ripeness of viscose are examined and discussed.
Although it appears that this bath produces regenerated cellulose in a single reaction, it is appearent that gelatination and regeneration processes must still occur either simultaneously ar in some definite, relative succession, depending upon the bath conditions. On the basis of above suggestion, all experimental results could be explained satisfactorily from a point of fundamental view confirmed in the previous study.

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First, in a fashion similar to procedure used in the previous studies, fine structures of cellulose gels coagulated freely with typical bath components such as Zn⁺⁺, Na⁺ and H⁺, were investigated with regard to their colloid-chemical behaviours upon viscose respectivly.
Next. using the fibres spun freely with acid bath only, fine structure of the cuticle layer (thin outermost layer) was examined by method of peeling-off.
It has been confirmed again that regenerated cellulose gel structure are divided into two classes which differ extremely in degree of crystallinity, -the α-type structure such as that of cellulose gel coagulated by Zn⁺⁺ and the cuticle layer, and the β-type structure such as that of cellulose gel coagulated by Na⁺ or H⁺. The most logical explanation for a difference in mechanisms between the α- and β- structure formations, appears to be a difference in speed of gelatination into xanthate gel. And it has been presumed that the α-type structure is formed when gelatination takes place momentarily in the order corresponding to the relaxation time of macromolecules in viscose.

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Rånby et al. had extracted nitrated pulp fibers with ethyl acetate-ethanol mixtures of increased ethyl acetate concentration, and found that the solubility curve thus obtained shows a level (Fig. 1). This fact means the carbohydrates are deposited in the plant fibers as two fractions differing markedly in solubility after nitration. In their investigation, two fractions were denitrated, hydrolyzed to monosaccharides and then analyzed by paper chromatography. This solvent-nonsolvent system gives a swelling of the fibers without destroying the fiber structure, until the concentration of ethyl acetate in mixture becomes about 60% (in volume). Therefore, the shape of this solubility curve can be effected not only by the amounts of easily soluble carbohydrates, but also the fiber structures, mainly outer layer of the cell wall and fine structure.
The purpose of this investigation has been to establish what effect the fiber structurs and average degree of polymerization of pulp could have on the shape of the fractional dissolution curve. The following samples were prepared for determining the solubility curve:
1. F-pulp fibers, which had been immersed in water, frozen and thawed, were prepared. This can be seen as destroyed of outer layer of cell wall or loosen fiber framework without the degradation of cellulose chain and the change of crystalline region.
2. Acid hydrolyzed pulp fibers were prepared under the mild conditions. This can be seen as degradated of cellulose chain and as destroyed of outer layer of cell wall without any change in crystalline region.
Two kinds of acid were used for hydrolysis of pulp fibers, namely sulfuric acid and lignosulfonic acid. According to the investigation by Samuelson, the latter had “screen effect”, then the outer layer of cell wall can be attacked more severely with lignosulfonic acid than with sulfuric acid.
3. Mercerized pulp fibers were prepared. This can be seen as disordered of the crystalline region without degradation of cellulose chain. A part of easily soluble carbohydrates goes into solution during mercerization treatment.
4. Linters pulp (Li. P), dissolving sulfite pulp (DSP), dissolving sulfate pulp (DKP), bleached paper sulfite pulp (BSP) and bleached paper sulfate pulp (BKP) were also used as original pulps.
Mitchell's mixture was used for nitration of pulp fibers and the fractional dissolution was performed in the way Rånby did. The shape of solubility curve has been expressed by l, h, α and s (Fig. 1).
As a result, it was found that l and α are effected by fiber structure, namely outer layer of cell wall and fine structure. When the outer layer of cell wall was destroyed or lateral order of cellulose was lowered, I decreased. In the case of DKP, the recrystallization had occured during freezing or acid hydrolysis and l increased. h shows the amounts of easily soluble carbohydrates in the fiber, and the shape s depends on the corelation between h and character of outer layer of cell wall. And the effect of average degree of polymerization of cellulose chain on the shape of fractional dissolution curve can be seen as subordinated to the fiber structure.

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In cotton and rayon staple fibre blend, it was studied how the yarn is elongated within constant sample length by stretching till it reaches the yarn breakage, and what connection the breaking elongation has with sample length.
Results obtained are:-
(1) On the former, in each blended yarn the elongation irregularity within sample length decreases gradually as tae sample is elongated and irrespective of breaking elongation the elongation of each part in the yarn tends to become uniform at the time of the yarn breakage.
(2) On the latter, with about 50% of s. f. blend, the minimum of breaking elongation appeae and moreover that blend tends to differ in elongation more remarkably lby changing the sample length than with other blends. Therefore, in 50% s. f. blend. tolerance limit of elongation is preferable to be made smaller than in other blends.

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The reduction power of sodium hydrosulphite and the oxidation power of hydrogen peroxide solution were measured in the presence of condensed polyphosphates or sodium metasilicate. Also the stability effect of the latter two salts on the bleaching power of above mentioned reagents were investigated by carrying out actually raw silk bleaching. The results are as follows:
(1). When each condensed polyphosphate is mixed with sodium hydrosulphite, almost any one of phosphates gives stability effect in low temperature.
The metaphosphate glass, however, produces the high stability effect in high temperature.
(2). The dissolving power of sodium hydrosulphite for sericin of raw silk is proportional to the amount of sodium hydrosulphite in the case of shorter period and it increases the white weight contained, while it shows opposite results in the case of 60 minutes section.
(3). When each condensed polyphosphate as a stabilizer is mixed with sodium hydrosulphite and raw silk is bleached, its dissolving power for sericin is proportional to the weight and treating period of these stability reagents and then the white weight contained also increases.
(4). Each condensed polyphosphate when mixed with hydrogen peroxide solution shows the high stability effect in low temperature, but little effects in high temperature and longer period.
(5). When condensed polyphosphate as a stabilizer is mixed with hydrogen peroxide and raw silk is bleached, its dissolving power for sericin is low and the amount of white weight contained is ereater in the case of shorter period, but entirely no effect in the case of longer period.

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For the purpose of practical applciation of methylation of silk fibroin fibers by diazomethane for the improvement of its light-resistance, diazomethane treatments in acetone medium were investigated at various conditions, in place of ether medium which is customarily used.
1. As the reaction medium, acetone is more effective for the higher degree of methylation than ether on account of its high boiling point.
2. Degree of methyltion is considerably affected by the moisture content of silk fiber before the treatment. Optimum moisture content for effective methylation is about 4% of silk.
3. External apperance and mechnical properties of silk are not at all changed by the methylation.
4. By the higher methylation (about 3% methoxyl content), the lightresistance of silk fiber is remarkably improved.
5. From the data of reaction rate and moisture absorption capacity of methylated silk, some considerations are carried on in relation to the accessibility of silk fibroin fiber.

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In order to know how easily chelate reaction in fiber takes place the energy of activation in the reaction of wool with Hg was determined. The same process as in the case of chelate resin was used. The reaction in wool is not essentially the same as in resin, but the degree of chelateformation in wool may be expected to be proportional to the adsorption of heavy metallic ions, therefore the reaction velocity of the chelate reaction of wool with Hg was determined by the adsorption velocity of Hg with wool. The Arrhenius equation is known to be widely applicable not only to homogeneous reaction but also to heterogeneous process. The equation which can be used in the case of chelate resin is different from the one for homogeneous reaction. The reaction rate (the quantity of Hg adsorbed by wool in a state is divided by the quantity of Hg adsorbed at equilibrium) and the time t have the following relationship:
This equation may be finally transformed to:-
This requires the plot of logxagainst logtto be a straight line, as long as log K is constant. From the points in Fig. 1, the linear relationship between logxand logtis evident. These experiments were done at three different temperatures of 10°, 20° and 30°C.
From the inclination of these straight lines and from the differnce between log xt₂₀, and log xt₁₀ or between log xt₃₀ and log xt₂₀, the energy of activation is computed and it is found to be 6800 cal/mol. between 10° and 20°C and 9600 cal./mol. between 20 and 30°C.

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It is known that the strength of silk can be changed by many processes. In order to prove that the introduction of chelate bond to fiber really increases the strength of silk, the relationship between the amount of Cu adsorbed by silk and the strength of the treated silk, and other factors which affect the strength of silk were taken into account. The strength of silk was greatly increased at the point of the greatest adsorption of Cu in Fig. 3. This tells us that Chelation. actually favours the strength of silk. Acid treatment of silk is known to change its strength under certain conditions, therefore silk was treated with acetic acid, HCl and HNO₃ respectively. The results were shown in Table 3 and 4.
To neglect the effect of acetic acid to the strength of Cu treated silk and that of Al treated one, washing of these treated silk with acetic acid was omitted, and the strength of those silk was measured as before, the results of which are shown in Table 2.

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Eighty-nine disperse dyes of aminoanthraquinone series were synthesized and their dyeability and fastness were examined. Relationship between structure and dyeability is discussed in terms of a/o and molecular size of dye. The a/o (inorganic property/organic property) is calculated by the use of Fuijita's conceptional diagram. The a/o is equivalent to hydrophility/hydrophobity. The average a/o value of dyes, having good dyeability on acetate, is about 1.25 and this is consistent with that of secondary cellulose acetate. It seems that the molecular size of dyes which can diffuse into cellulose acetate is less than about 13 Å in normal dyeing process. The light fastness of dyes decreases in the following order. 1-Amino-4-hydroxyanthraquinones>1, 4-Diaminoanthraquinones>1, 4, 5-Triamino-8-hydroxyanthraquinones>1-Aminoanthrquinones>1, 4, 5, 8-Tetraminoanthraquinones. An electron attractive N-substituent, such as β-chloroethoxycarbonyl group, increases the light fastness and an electron donating group, such as β-hydroxyethyl group, decreases the light fastness. It seems that the a/o ratio of dyes, having poor wash fastness, is more than 1.25, and the molecular size of the dyes is less than about 11.0Å.

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Recently the azoic coupling components containing polycyclic nucleus have become very important because of their production of characteristic shades and of their very high substantivity for cotton.
In regard to these properties we prepared a number of coupling components containing fluorene ring in their molecule and examined their dyeing character on cotton.
These components consist of two series. One of which contains arylides of 3-hydroxyfluorene-2-carboxylic acid, i. e. anilide, o-, m-toluidide and o-, p-anisidide. Although the solubility of these compounds in alkaline grounding bath was not enough, and they developed fully only when pH of the developing bath was adjusted at near 7, they gave very valuable khaki or olive shade on cotton. The light-fastness of their dyeing was fair or good and wash fastness was excellent.
Another series of the coupling components prepared contains fluoreneamides of 2-hydroxy-3-naph-thoic acid. Their solubility in alkaline grounding bath was poor except 3-methoxyl-2-fluorenea-mide. 3-Fluoreneamide and 3-methoxy-2-fluoreneamide dyed cotton very effectively compared with 2-fluoreneamide or 7-methxoxy-2-fluoreneamide. Light-fastness of these dyeings was good, especially 3-methoxy-2-fluoreneamide gave cxcellent. Wash-fastness was equally excellent.

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The dyeing properties of acid azo dyes having the same skeletal structure as p-X-aniline→γ-acid (2-amino-6-sulfo-8-hydroxynaphthalene) (alkali- and acid-coupling) were determined qualitatively, where X are H, SO₃H, SO₂NH₂, COOH, COOC₂H₅, Cl, CH₃, OCH₃, OC₂H₅, NO₂, NH₂, NHCO CH₃ and NH-_??_, respectively.
The absorption spectra of aqueous solution of alkali-coupling dyes (γA) and acid-coupling dyes (γS) in visible region are very different in shape, γA have two absorption maxima and γS have one maximum, then the shade on wool dyeings of the former are much duller than that of the latter.
The dyeing rate of γS on wool colth from boiling bath is larger than that of γA. All of these dyes used have a considerable affinity to wool from neutral dyeing condition, especially X=H, Cl, NO₂.
The light fastness of dyeings of γS is better than that of γA, and the wash fastness is vice versa.

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For fundamental studies of vinylon dyeing, the sorption of congo red in P. V. A. had been previously investigated. On the basis of these results, sorption phenomena of congo red molecules in P. V. F. film are studied here in the same manners.
P. V. F. samples were prapared from which P. V. A. films without heat-treatment were formalized. The formalization degree might be uniform at the surface part and the inner part of the film. The sorption isotherms were studied on the samples of various formalization degrees 3, 10, 30, 50, 70, 85mol%
Sorption isotherms were not systematically shifted as formalization degree and temperature varied, when the amount of sorbed dye were represented as the weight of sorbed dye against the unit weight of dried film-Dω. If the amount of sorbed dye were, on the other hand, represented as the weight of sorbed dye against the unit weight of dyed swelled film-D_s, the sorption isotherms changed systematically. The isotherms consisted of two parts-Langmiur's type part and partition type part as described before.
In lower formalization degree Langmiur's type part took place more than the partition part, and it was contrary in the case of higher formalization degree.

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Heterogenous formalization reaction of heat treated P. V. A. film was studied.
How the distribution of formalization degree in film changed during reaction was first considered.
Sorption isotherms of congo red in P. V. F. films (15, 21, 32, 39, 43 mol%) were studied. The amount of sorbed dye is represented by D_s as described before.
The results of similar tendency as previously reported (I) were obtained.

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