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CN-121975123-A - Alkoxy active group terminated modified siloxane and preparation method thereof

CN121975123ACN 121975123 ACN121975123 ACN 121975123ACN-121975123-A

Abstract

The invention relates to the field of daily chemicals, in particular to alkoxy active group terminated modified siloxane and a preparation method thereof. The siloxane molecular structure comprises an ethoxy-terminated linear siloxane main chain, an intermediate amino-containing side chain unit and a methyl siloxane unit. The preparation method comprises the steps of hydrolytic condensation, negative pressure dehydration, ring opening and end sealing and the like, and the technological parameters are precisely controlled to ensure the performance of the product. The amino side chain and the alkoxy end group are synergistic, so that the flexibility, the damage resistance and the moisturizing effect of the hair are obviously improved, the residual risk is reduced, and the preparation method is suitable for large-scale industrial production and has obvious technical progress and market prospect.

Inventors

  • REN SHUBO
  • WANG DU
  • YU GANG

Assignees

  • 杭州赛肯新材料技术有限公司

Dates

Publication Date
20260505
Application Date
20260205

Claims (9)

  1. 1. The modified siloxane is characterized by comprising a linear siloxane main chain with alkoxy groups as end sealing groups at two ends and a middle part, wherein the linear siloxane main chain is composed of three sections, the first section of the middle part is a siloxane unit with an amino side chain, the second section of the middle part is a pure methyl siloxane unit, the third section of the middle part is a siloxane unit with an amino side chain again, the number of the repeating units of the siloxane unit with the amino side chain is 1-50, the number of the repeating units of the pure methyl siloxane unit is 10-200, and the structure of the amino side chain is a specific long-chain amino functional group connected by a carbon chain.
  2. 2. The alkoxy-reactive group-terminated modified siloxane of claim 1, wherein the amino side chain has the structure-CH 2CH2NHCH2CH2NH2.
  3. 3. The alkoxy-reactive group-terminated modified siloxane of claim 2, wherein said amino side chain is attached to the silicon atom via a carbon chain.
  4. 4. The alkoxy-reactive group-terminated modified siloxane of claim 1, wherein said alkoxy groups are methoxy or ethoxy groups and the number of said alkoxy-blocking groups is two.
  5. 5. A process for preparing the modified siloxane blocked by alkoxy active group as defined in claim 1, which comprises the steps of adding N-aminoethyl-gamma-aminopropyl triethoxysilane into a reaction vessel, heating to 50 ℃ under the protection of nitrogen, stirring, continuously dripping a mixture of ethanol and water for hydrolysis condensation reaction, carrying out negative pressure low-pressure operation at 65-85 ℃ until no low-boiling substances are removed, finally adding D4 and a base catalyst for ring-opening blocking reaction, carrying out low-temperature removal treatment after the reaction is completed, and finally obtaining a colorless transparent liquid.
  6. 6. The process according to claim 5, wherein the temperature of the hydrolytic condensation reaction is controlled to be 20 to 50 ℃ and the reaction time is 2 to 3 hours.
  7. 7. The process according to claim 5, wherein the amount of the base catalyst is 20 to 120ppm based on the total mass of N-aminoethyl-gamma-aminopropyl triethoxysilane and D4, the base catalyst is added in a small amount and a plurality of times, and the reaction time of the ring opening end capping reaction is 3 to 5 hours.
  8. 8. The method of claim 5, wherein the mass ratio of N-aminoethyl-gamma-aminopropyl triethoxysilane, water and D4 is in the range of 2:1:10 to 5:2:25.
  9. 9. The method of claim 5, wherein the stirring rate is between about 300 rpm and about 400 rpm.

Description

Alkoxy active group terminated modified siloxane and preparation method thereof Technical Field The invention belongs to the technical field of daily chemical products, and particularly relates to alkoxy active group terminated modified siloxane and a preparation method thereof. Background Silicone oils are widely used as key functional ingredients in the daily chemical field, particularly in hair care products, to improve the appearance and feel of hair. The traditional amino silicone oil can be adhered to the surface of hair to fill gaps among hair scales, reduce friction damage, and endow hair with smoothness and luster, so that the amino silicone oil becomes a core component of a plurality of shampoos and hair conditioners. However, the existing amino silicone oil still has significant defects in practical application. Although it can improve the hair quality in a short period of time, the restoration effect on the hair quality is difficult to last, and long-term use may cause the silicone oil to remain on the scalp and hair, so that the hair becomes heavy gradually, loose feeling is lost, and especially the effect on the fine and soft hair quality is more obvious. In addition, conventional silicone oils are relatively hydrophobic, and the protective film formed on the hair surface may hinder moisture exchange, resulting in "stuffy feel" to the hair and further exacerbating the problem of moisture loss from dry hair. Meanwhile, along with the continuous improvement of the hair care demands of consumers, especially the increasingly-increased repair and moisturizing demands of dry, damaged or dyed hair, the development of a novel silicone oil with both repair function and long-acting moisturizing capability becomes a technical problem to be solved. In the prior art, the silicone oil modification method is mostly focused on optimization of a single function, for example, the flushing performance is improved by introducing hydrophilic groups, or the short-term smooth effect is improved by enhancing the adhesion capability of the silicone oil, but the method is difficult to simultaneously meet multiple requirements of repairing, moisturizing, residue reduction and the like. Therefore, how to design a silicone oil material which can not only effectively repair hair damage, but also enhance the moisture retention capability of hair and avoid negative effects caused by long-term use becomes an important direction for the technical development of the current hair washing and caring products. The invention aims to solve the technical problems, and by introducing the modified siloxane structure of the end capping of the alkoxy active group and combining the advantages of the amino side chain and the alkoxy end group, the comprehensive repair and long-term protection of the hair are realized. The novel silicone oil not only can fill gaps among hair scales and reduce mechanical damage, but also can form an air-permeable protective film on the surface of hair through the hydrophilic characteristic of alkoxy groups so as to help maintain the water balance in the hair, thereby remarkably improving the dryness and the damaged hair quality. In addition, the material shows more thorough cleaning performance in the flushing process, effectively reduces the residual risk of silicone oil on the scalp, and provides a brand new technical path for developing high-performance hair-washing products. Disclosure of Invention Aiming at the technical problems of poor continuous restoration effect and easiness in residue in losing fluffy sense of hair in the existing amino silicone oil in hair-washing products, the invention provides alkoxy active group end-capped modified siloxane with restoration and moisturizing functions and a preparation method thereof. According to the technical scheme, the amino side chain and the alkoxy end group with specific structures are introduced, so that the damaged hair quality is effectively repaired, and the long-term moisturizing capability is improved. The invention provides a modified siloxane with end-capped alkoxy active groups, which comprises a linear siloxane main chain with ethoxy groups (OEt) at two ends as end-capped groups, wherein the middle part of the modified siloxane consists of three sections, wherein the first section is a siloxane unit [ Si (OEt) (NH 2) ] x with an amino side chain, the second section is a pure methyl siloxane unit [ Si (CH 3)2 ] y, the third section is a siloxane unit [ Si (OEt) (NH 2) ] z. with an amino side chain, x, y and z respectively represent the number of repeating units of each section, and the value of x and z ranges from 1 to 50, and the value of y ranges from 10 to 200. Further, the structure of the amino side chain is-CH 2CH2NHCH2CH2NH2, which is connected with silicon atoms through carbon chains, so that the uniformity of distribution and the reactivity of amino functional groups in molecules are ensured. Further, the amino side chain is linked to t