To provide an aqueous solution of a high molecular weight sericin, which suppresses formation, flocculation and precipitation of colloidal gel and has excellent homogeneity by improving solubility of high molecular weight sericin using a cationic surfactant.
The aqueous solution of high molecular weight sericin comprises a sericin having a weight-average molecular weight of 30,000 and at least one cationic surfactant composed of a quaternary ammonium salt represented by formula (1): [(R1)(R2)pN(R3)q(CH3)3-p-q]+X- (wherein R1 and R2 are each a 16-22C alkyl group; R3 is a benzyl group; X is a halogen; and p and q are each 0 or 1 and at least one is 0) and an amidoamine compound represented by formula (2): R4-CONH-(CH2)n-NR5R6 (wherein R4 is a 15-21C alkyl group; R5 and R6 are each a 1-4C alkyl group; and n is an integer of 1-4).
MORI TOSHIKI
Masato Tsuda
Tetsuji Nakamura
Katsuyuki Tomita
Husband
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