Aqueous solution containing hydroxylamine salt and storing method thereof

An aqueous solution comprising a hydroxylamine salt in an amount of 18 to 35 weight-%, wherein the aqueous solution further comprises at least one compound selected from the group consisting of sorbitan polyethylene oxides, derivatives of sorbitan polyethylene oxide and compounds represented by the following Formulas [7] or [8] in an amount of 0.1 to 10 weight-%, and pH of the aqueous solution is within the range of from 2 to 6:

• A—O—(B)m—(C)n—X Formula [7]
• wherein A represents a monovalent organic group or an aryl group substituted by an alkyl group having 1 to 35 carbon atoms or by an alkenyl group having 2 to 35 carbon atoms;
• B and C, which may be the same or different, each represents
• in which a, b and c each are 0, 1, 2 or 3, d is 0 or 1, and Y is a hydrogen atom or a hydroxyl group;
• m and n each represent an integer of 1 to 100;
• X represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group;
• A—O—(CH2CH2O)n—SO3M Formula [8]
• wherein M represents an alkali metal, a hydrogen atom, an ammonium salt or an alkanolamine salt;
• n is an integer of 1 to 100;
• and A represents a monovalent organic group or an aryl group substituted by an alkyl group having 3 to 20 carbon atoms.

A storing method of an aqueous solution comprising a hydroxylamine salt in an amount of 18 to 35 weight-%, wherein the storing method comprises a step of storing the aqueous solution in an plastic container having an oxygen permeation coefficient at 20° C. and 65% RH of not more than 40 ml/m2·atm·day, and wherein the aqueous solution further comprises at least one compound selected from the group consisting of amino polycarboxylic acids and compounds represented by the following Formulas [1] to [6] in an amount of 1 to 30 weight-%, and pH of the aqueous solution is within the range of from 2 to 6:

• wherein R1 through R7 each represent independently a hydrogen atom, —OH, —COOM, —PO3M2, —SO3M or a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, in which M is a hydrogen atom or an alkali metal;
• n and m each represent 0 or 1, provided that both m and n are not 0 at the same time;
• wherein at least one of A through F represents a sulfonic acid group or a sulfonic acid ester group, and the others represent a hydrogen atom, a halogen atom, a hydroxyl group or a saturated or unsaturated alkyl group;
• wherein, at least one of G through N represents a sulfonic acid group or a sulfonic acid ester group, and the others represent a hydrogen atom, a halogen atom, a hydroxyl group or a saturated or unsaturated alkyl group;
• R41—SO3M Formula [4]
• wherein R41 represents a substituted or unsubstituted, saturated or unsaturated hydrocarbon group having 1 to 20 carbon atoms, and M represents a hydrogen atom, or an alkali metal;
• HO—(A1—O)l1—(A2—O)l2—(A3—O)l3—H Formula [5]
• wherein A1, A2, and A3 each represent a substituted or unsubstituted, straight or branched chain alkylene group, which may be the same or different;
• l1, l2, and l3 each represent 0 or an integer of 1 to 500;
• wherein R1 represents a substituted or unsubstituted hydroxyalkyl group or a substituted or unsubstituted aminoalkyl group;
• and R2 and R3 each represent a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted hydroxyalkyl group or a substituted or unsubstituted benzyl group, provided that R1 and R2, R2 and R3, R3 and R1, or R1, R2 and R3 may combine with each other to form a ring.

A storing method of an aqueous solution comprising a hydroxylamine salt in an amount of 18 to 35 weight-%, wherein the storing method comprising a step of storing the aqueous solution in an plastic container having an oxygen permeation coefficient at 20° C. and 65% RH of not more than 40 ml/m2·atm·day, and wherein the aqueous solution further comprises at least one compound selected from the group consisting of sorbitan polyethylene oxides, derivatives of sorbitan polyethylene oxide and compounds represented by the following Formulas [7] or [8] in an amount of 0.1 to 10 weight-%, and pH of the aqueous solution is within the range of from 2 to 6:

• A—O—(B)m—(C)n—X Formula [7]
• wherein A represents a monovalent organic group or an aryl group substituted by an alkyl group having 1 to 35 carbon atoms or by an alkenyl group having 2 to 35 carbon atoms;
• B and C, which may be the same or different, each represents
• in which a, b and c each are 0, 1, 2 or 3, d is 0 or 1, and Y is a hydrogen atom or a hydroxyl group;
• m and n each represent an integer of 1 to 100;
• X represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group;
• A—O—(CH2CH2O)n—SO3M Formula [8]
• wherein M represents an alkali metal, a hydrogen atom, an ammonium salt or an alkanolamine salt;
• n is an integer of 1 to 100;
• and A represents a monovalent organic group or an aryl group substituted by an alkyl group having 3 to 20 carbon atoms.