Michiharu Negishi

Part II: Formaldehyde-Curing after Amidoximation:

By amidoximation with the aqueous hydroxylamine and subsequent formaldehyde-curing in the presence of a weak acid catalyst such as ammonium acetate or even in the absence of catalyst, the crease resistance of cyanoethylated cotton fabrics containing a low percentage of nitrogen was improved significantly without much loss in the tensile strength and elongation, but a decrease in the flex abrasion and tear strength occurred. From the results, it was deduced that the longer cross link chain might be formed to some extent between adjacent amidoxime or hydroxamic acid groups in different cellulose molecules. After curing, the amidoximates retain great affinities for acid dyes and have a wool-like hand.

Cross-Linking of Partially Cyanoethylated Cotton: Part III: Acid Scouring of Amidoximate and Subsequent Formaldehyde-Curing

By 0 1-0.5% hydrochloric acid scouring, which has been shown to prevent the dis coloration of the amidoximates of partially cyanoethylated cotton fabrics in the previous paper, it was found that the amidoximate hydrochloride salt might be formed. In com parison with unscoured amidoximates, the scoured matertal, even when formaldehyde- cured under noncatalyzed neutral conditions, with or without tension, had exceedingly improved crease resistance without much loss in tensile strength, elongation, and tear strength. The softness of cotton was retained. It was deduced that the amidoximate hydrochloride might presumably split off hydrochloric acid and act as a self-catalyst in the formaldehyde-curing.

Grafting of Vinyl Monomers onto Crosslinking Polymers. II. Grafting of Acrylonitrile and Styrene ont o Fibers Spun from Polymer Blends of Polyvinyl Alcohol and its Partially N-Methylol Carbamoylethylated Products

N-メチロール基を拠点として橋かけ構造を導入したポリビニルアルコール系合成繊維の耐熱水性,弾性向上および熱固定性の付与を目的として,ポリビニルアルコール(PVA)と置換度約15mol%のN-メチロールカルバモイルエチル化ポリビニルアルコール(PVM)との混合紡糸熱処理繊維(PVM0～20%)を酸処理あるいはそれを行なうことなくセリウムイオン法によりアセトン-水系でアクリロニトリル(AN)およびスチレン(St)を30℃ および50℃ でグラフト共重合させた。PVM混合紡糸繊維はいずれのモノマーでも純PVM繊維に比してグラフトされやすいが,それらは既報のメチルメタクリレート(MMA)よりもグラフトされ難い。すなわち,ANの場合は高グラフト率を得ることは困難であり,またStの場合にはMMAよりも高温および長時間を必要とした。グラフト繊維の耐熱水性はAN>St>MMAグラフトの順であり,グラフト率の増加およびグラフト前の酸処理によって耐熱水性が向上することはMMAグラフトの場合と同挙動である。たとえば酸処理を行なったPVM20%混合繊維は30%程度の低いANグラフト率で数%の熱水収縮率を示した。また,グラフト繊維の伸長弾性度はStよりもANグラフトの方がすぐれており,その向上は既報MMAグラフトの場合とほぼ同程度であった。すなわち,酸処理後ANでグラフトしたPVM20%混合繊維は5%以下の低伸長部分では純PVA未処理繊維よりも,また,全伸長域においては常法ホルマール化純PVA繊維よりも明瞭に高い弾性度を示している。グラフト繊維の引張り強力はいずれもグラフト率の増加とともに若干増加し,1デニール当りの強力増加係数はAN,StおよびMMAグラフト繊維において,それぞれ1.2,0.7および0.5であった。また,ANグラフト繊維の伸度はMMAの場合と同程度にグラフト率の増加にともなってわずかに増加したが,Stの場合にはほとんど変化しなかった。グラフト繊維の吸湿率はグラフト率の増加にともなってAN>MMA>Stの順に減少した。熱固定性はいずれのグラフト繊維にも付与され,その程度はSt≒MMA>ANであった。

Benzalization of Synthetic Fibers from Polymer Blends Containing Polyvinyl Alcohol and Partially Carbamoylethylated Polyvinyl Alcohol or its N-Methylolated Product

分子間橋かけ構造を導入したポリビニルアルコ一ル(PVA)系合成繊維の弾性度向上を主目的として,置換度約17mol%の水溶性部分カルバモイルエチル化PVA(PVB)およびそのN-メチロール化物(PVM)とPVAとの混合紡糸を行ない,PVB混合熱処理繊維は繊維状N-メチロール化(M化)後あるいはそれを行なうことなくベンズアルデヒド処理(B化)を,またPVM混合繊維はB化のみを行なってそれら処理繊維の各種性能を測定した。B化繊維の耐熱水性はPVB(0～30%)混合系では混合率の大なるほど,またPVM(0～30%)混合系では混合率10%において最もすぐれ,数%の熱水収縮率を示した。これは同程度の耐熱水性を有する純PVA繊維よりも明瞭により少ないB化度を示している。またこれらの後処理繊維は引張り強伸度および結節強伸度の劣化を伴なうことなく,低伸長域においてB化PVA繊維に比べてすぐれた弾性度を示したが,耐熱水性,弾性ともにその向上効果は前報ホルマール化(F化)の場合と同程度である。B化繊維の耐酸性はPVBあるいはPVM混合によって著しく改善される。以上の結果からB化混合繊維の場合にも,F化の場合と同様にカルバモイル基,N-メチロール基あるいはそれらとビニル水酸基間に形成される分子間橋かけ化の寄与が大きいものと考察した。なおこれらの後処理繊維の直接および酸性染料に対する染色性もある程度改善された。

Effects of Buffers on Formaldehyde-Curing of Amidoximate Hydrochloride of Partially Cyanoethylated Cotton

Dear Sir: In the previous publications from our laboratory, it was reported that the hydrochloric acid scouring of the amidoximation products of partially cyanoethylated cotton fabrics not only prevents discoloration but brings about a catalytic action in the formaldehyde-curing by forming the al1lidoxil1late hydrochloricie salt [ 1, 2 J . However, there is some 1>ossibility that part of the amidoxime or hydroxamic acid groups between which the long intermolecular crosslinks have been considered to be formed is subjected

AMIDOXIMATION OF PARTIALLY CYANOETHYLATED COTTON FABRIC

Researches on the amidoximation of N % 3_??_5 partially cyanoethylated cotton fabric with the aqueous NH2OH•HCl solution were carried out, including the effects of temperature and pH of reaction bath, concentration of NH2OH • HCl NH2OH/CN mol ratio and addition of nonionic surface active agent on the rate of amidoximation and the mechanical properties of the treated fabric. The results obtained are as following:For amidoximation, the neutral or minute alkaline solution of NH2OH and the temperature of 80°C and above are the necessary. The addition of nonionic active agent gives little retarding effect on the rate of amidoximation. Above and below about 15 of NH2OH/CN mol ratio, the relation of the first and the second order reaction is approximately applied respectively. The discolouration from pale blue to yellowish pale brown with the increase of the amidoximation takes place, while the discolouration of the lower amidoximation is small.By the amidoximation, especially the lower amidoximation of lower cyanoethylated cotton and the slower raising of reaction temperature, the crease and flex abrasion resistance as well as moisture regain increase considerably, retaining the most part of the tensile strength, elongation, tearing strength and softness of untreated fabrics. Generally, even the lower degree of amidoximation gives a striking increase of the acid dyestuff affinity and a great decrease of the basic dyestuff affinity. However, the affinity for the acid dyestuff “Eosine” is lost by the amidoximation.

Reaction Velocity of Carbamylethylation of Partially Cyanoethylated Polyvinyl Alcohol with Hydrogen Peroxide

水溶性部分シアノエチル化ポリビニルアルコールの微アルカリ性過酸化水素によるカルバミルエチル化に関する前報の実験結果および若干の追加実験結果に基いて, カルバミルエチル化度, カルボキシエチル化度および脱エーテル化度を計算した。また, カルバミルエチル化について反応速度論的考察を行い, 微少なカルボキシエチル化度を無視して, カルバミルエチル化度に一つの極大をもつ次式が近似的に適用されることを認めた。x=ae-k2t(1-e-k1t)aは-CN基の初濃度,xはt時間後に生成された-CO・NH2基数,k1およびk2はそれぞれカルバミルエチル化および脱エーテル化反応を1次式によるとした場合の反応速度定数。なお,k1/k2は500～1000程度と推定された。

STUDIES ON THE TREATMENT OF SILK FIBERS BY DIAZOMETHANE

For the purpose of practical application of methylation of silk fibers by diazomethane for the improvement of its light-resistance, some checks and improvements of diazomethane synthesis and selection of its slovents were investigated.1. New method of diazomethane synthesis by Boer and Backer (Recueil, 73 229, 1954) is more favorable than other customary methods in respects of simplicity of preparation, stability of intermediate nitrosomethyl compound and the yield of diazomethane.2. By some modifications to the Boer and Backers method, as the common solvent for generation and adsorption of diazomethane, the employment of acetone in place of ether is possible, keeping good yield and safety of the operation like in the ether solvent.3. In anhydrous acetone, diazomethane is more stable than in the other usual solvents (ether, methanol, chloroform, carbontetrachloride etc.) and the methylation of silk in the acetone solution is carried out satisfactorily as well as in the ether solution.

PREPARATION OF SYNTHETIC FIBERS FROM A MIXTURE OF POLYVINYL ALCOHOL AND POLYVINYL CYANOETHYLETHER

Easily dyeable fibers can be obtained from a solution of a mixture of polyvinyl alcohol and polyvinyl cyanoethylether whose degree of cyanoethylation is lower than 25 mol percents. The mechanical properties of these fibers are similar to the ordinary vinylon.