A method for preparing waterproof down

Abstract

The invention discloses a method for preparing waterproof down, and relates to the technical field of down processing. The method comprises the following steps: firstly, adding down, water, detergent and softener into a washing machine to wash the down; then, uniformly mixing epoxysilane, ethanol and water in proportion to obtain a hydrolyzed silanol solution of the epoxysilane; and then, using a two-step impregnation method, successively impregnating the down into an acidic siloxane solution and a weakly alkaline siloxane solution to form a strongly bonded waterproof film on the down through a chemical reaction, thereby improving the waterproof performance and waterproof durability of the down without affecting the fluffiness, softness and comfort of the down itself.

Description

Technical field:

[0001] The invention relates to the technical field of down processing, and in particular to a method for preparing waterproof modified down. Background technology:

[0002] As consumers' demands for textiles continue to rise, the demand for cold-weather textiles has evolved from traditional warmth protection to high-efficiency warmth that combines fashion and comfort. Down, with its lightweight and excellent warmth retention, is widely used in this field. However, down has a high moisture regain and easily absorbs moisture from the surrounding environment. When down absorbs large amounts of water and becomes wet, its lofty structure is severely damaged, significantly reducing the thermal resistance of the down and the aggregate, rapidly increasing the heat transfer coefficient and causing significant heat loss, which in turn affects the down's normal thermal insulation properties.

[0003] Waterproofing down makes it moisture-proof and quick-drying, and it can still maintain high fluffiness and warmth in humid environments. It is of great significance to promote the development of the down processing industry and meet market requirements.

[0004] Existing methods for improving the waterproofness of down mainly include: first preparing a waterproof finishing liquid or a waterproof dispersion system, and then treating the down. However, the down treated with the finishing agent has a reduced feel and fluffiness, and secondly, the durability of the waterproof performance is poor. Down filling with a certain waterproof effect can be prepared by mixing down with other waterproof-modified synthetic fibers, but this mixing may affect its cold-proof and warming properties. Summary of the invention:

[0005] The technical problem to be solved by the present invention is to provide a method for preparing waterproof modified down with good waterproof performance and waterproof durability, so as to solve the problems that the waterproof modification methods commonly used in the prior art will affect the fluffiness of the down and have poor waterproof durability.

[0006] The technical problem to be solved by the present invention is achieved by adopting the following technical solutions:

[0007] One of the objects of the present invention is to provide a method for preparing waterproof modified down, comprising the following steps:

[0008] (1) Add down, water, detergent and softener into a washing machine and wash the down;

[0009] (2) mixing epoxysilane, ethanol and water in proportion to obtain a hydrolyzed silanol solution of epoxysilane;

[0010] (3) dipping the down pretreated in step (1) into the hydrolyzed silanol solution of epoxysilane prepared in step (2), adjusting the pH value of the system to 3-5 with an acid, and keeping the dipping warm; adjusting the pH value of the system to 7.5-9 with an alkali, and continuing to keep the dipping warm. After the dipping is completed, the down is separated and naturally dried to obtain waterproof modified down.

[0011] Preferably, the mass ratio of the down to water is 1:(10-40).

[0012] Preferably, the washing temperature is room temperature to 60° C., and the washing time is 30 to 60 minutes.

[0013] Preferably, the detergent is a nonionic surfactant.

[0014] Further preferably, the detergent is a nonionic surfactant with the trade name Ultravon CN.

[0015] Preferably, the dosage of the detergent is 2-4 g / L.

[0016] Preferably, the softener is a conventional textile bulking softener.

[0017] More preferably, the softener is a modified amino silicone oil softener.

[0018] Preferably, the amount of the softener is 0.5 to 2 g / L.

[0019] Preferably, the molar ratio of the epoxysilane, ethanol and water is 1:(2-5):(5-15).

[0020] Preferably, the epoxysilane is one or both of γ-glycidyloxypropyltrimethoxysilane (GPTMS) and γ-glycidyloxypropylmethyldimethoxysilane (GPDMS). Other epoxy-containing silane coupling agents known in the art may also be used.

[0021] Preferably, the mass ratio of the down to the hydrolyzed silanol solution of epoxy silane is 1:(80-100).

[0022] Preferably, the acid is hydrochloric acid or acetic acid. Acid is added to the hydrolyzed silanol solution of epoxysilane and the pH value is adjusted to 3-5 to obtain a siloxane acidic solution.

[0023] Preferably, the base is sodium carbonate. Adding base to the hydrolyzed silanol solution of epoxysilane and adjusting the pH value to 7.5-9, a weakly alkaline siloxane solution is obtained.

[0024] Preferably, the temperature of the heat preservation immersion is 30-60° C. The heat preservation immersion is performed under stirring.

[0025] A second object of the present invention is to provide a waterproof modified down prepared according to the above-mentioned preparation method.

[0026] Preparation principle of the waterproof modified down of the present invention:

[0027] The present invention utilizes the property that epoxy groups easily undergo a ring-opening reaction with amino groups under acidic conditions. By adjusting the pH value and temperature of the impregnation solution, conditions are provided for the epoxy groups in the epoxysilane structure to undergo a covalent reaction with the amino groups contained in the down molecules, thereby improving the bonding strength between the siloxane and the down. In addition, the present invention utilizes the property that silanols after hydrolysis of epoxysilane undergo a self-condensation reaction in a weakly alkaline environment to form an in-situ waterproof network structure covering the surface of the down.

[0028] The beneficial effects of the present invention are:

[0029] (1) The present invention pre-treats down, which is beneficial to the adsorption of siloxane;

[0030] (2) The present invention adopts a two-step impregnation method to successively immerse the down in a silicone acidic solution and a silicone weak alkaline solution, thereby forming a strongly bonded waterproof film on the down through a chemical reaction, thereby improving the waterproof performance and waterproof durability of the down, while not affecting the fluffiness, softness and comfort of the down itself. Specific implementation method:

[0031] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0032] Add 50mL of distilled water to a conical flask, fix 1g of down sample with a thread, hang it in the bottle, cover the bottle tightly, and place it in a 65±1℃ oven for 4h. Take out the conical flask and cool it for 30min. Take out the down and weigh it. The change in the down mass (i.e., moisture absorption) is used to characterize its waterproof performance.

[0033] After washing the down using conventional methods, its moisture absorption is tested again to characterize the durability of its waterproof performance.

[0034] Example 1

[0035] Add 1 part down and 20 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 4g / L and 1g / L respectively. Wash at 40℃ for 40 minutes, and let the washed down dry naturally.

[0036] GPTMS, ethanol, and water were mixed uniformly in a molar ratio of 1:2:5. Cleaned down was then added (the mass ratio of down to silicone solution was 1:100). The pH of the system was adjusted to 5 with dilute hydrochloric acid, and the mixture was heated to 40°C and stirred for 6 hours. The pH of the system was then adjusted to 7.5 with sodium carbonate, and the mixture was stirred and immersed at 40°C for another 2 hours. After the impregnation, the down was separated and air-dried to obtain fluffy, soft, and waterproof modified down.

[0037] Example 2

[0038] Add 1 part down and 40 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 0.5g / L respectively. Wash at room temperature for 60 minutes and let the washed down dry naturally.

[0039] GPTMS, ethanol, and water were mixed uniformly in a molar ratio of 1:5:15. Cleaned down was then added (the mass ratio of down to silicone solution was 1:80). The pH of the system was adjusted to 3 with dilute hydrochloric acid, and the mixture was heated to 30°C and stirred for 4 hours. The pH was then adjusted to 9 with sodium carbonate, and the mixture was stirred and immersed at 30°C for another 2 hours. After the immersion, the down was separated and air-dried to obtain fluffy, soft, and waterproof modified down.

[0040] Example 3

[0041] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 3g / L and 2g / L respectively. Wash at 60℃ for 30 minutes and let the washed down dry naturally.

[0042] GPTMS, ethanol, and water were mixed uniformly in a molar ratio of 1:3:10. Cleaned down was then added (the mass ratio of down to silicone solution was 1:80). The pH of the system was adjusted to 4 with dilute acetic acid, and the mixture was heated to 50°C and stirred for 6 hours. The pH was then adjusted to 8 with sodium carbonate, and the mixture was stirred and immersed at 50°C for another 4 hours. After the impregnation, the down was separated and air-dried to obtain fluffy, soft, and waterproof modified down.

[0043] Example 4

[0044] Add 1 part down and 20 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 4g / L and 1g / L respectively. Wash at 50℃ for 30 minutes and let the washed down dry naturally.

[0045] GPDMS, ethanol, and water were mixed uniformly in a molar ratio of 1:3:15. Cleaned down was then added (the mass ratio of down to silicone solution was 1:100). The pH of the system was adjusted to 5 with dilute acetic acid, and the mixture was heated to 60°C and stirred for 6 hours. The pH was then adjusted to 8 with sodium carbonate, and the mixture was stirred and immersed at 60°C for another 3 hours. After the impregnation, the down was separated and air-dried to obtain fluffy, soft, and waterproof modified down.

[0046] Example 5

[0047] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 1g / L respectively. Wash at 40℃ for 60 minutes and let the washed down dry naturally.

[0048] GPDMS, ethanol, and water were mixed uniformly in a molar ratio of 1:4:12. Cleaned down was then added (the mass ratio of down to silicone solution was 1:90). The pH of the system was adjusted to 4 with dilute acetic acid, and the mixture was heated to 40°C and stirred for 4 hours. The pH was then adjusted to 8 with sodium carbonate, and the mixture was stirred and immersed at 40°C for another 3 hours. After the impregnation, the down was separated and air-dried to obtain fluffy, soft, and waterproof modified down.

[0049] Comparative Example 1

[0050] The difference between Control Example 1 and Example 5 is that the pH value of the system is adjusted to 10 during the immersion in the siloxane alkaline solution.

[0051] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 1g / L respectively. Wash at 40℃ for 60 minutes and let the washed down dry naturally.

[0052] GPDMS, ethanol, and water were mixed in a molar ratio of 1:4:12. Cleaned down was then added (the mass ratio of down to silicone solution was 1:90). The pH of the system was adjusted to 4 with dilute acetic acid, and the mixture was heated to 40°C and stirred for 4 hours. The pH was then adjusted to 10 with sodium carbonate, and the mixture was stirred and immersed at 40°C for another 3 hours. After the impregnation, the down was separated and air-dried to obtain a waterproof modified down with a slightly reduced fluffiness and a slightly astringent feel.

[0053] Comparative Example 2

[0054] The difference between Control Example 2 and Example 5 is that only the siloxane acid solution is immersed, and the siloxane weak alkaline solution is not immersed.

[0055] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 1g / L respectively. Wash at 40℃ for 60 minutes and let the washed down dry naturally.

[0056] GPDMS, ethanol, and water were mixed in a molar ratio of 1:4:12. Cleaned down was then added (the mass ratio of down to silicone solution was 1:90). The pH of the system was adjusted to 4 with dilute acetic acid. The mixture was heated to 60°C and stirred for 4 hours. After the impregnation, the down was separated and air-dried to obtain a fluffy, soft modified down.

[0057] Comparative Example 3

[0058] The difference between Control Example 3 and Example 5 is that only the weak alkaline siloxane solution is immersed, and the acidic siloxane solution is not immersed.

[0059] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 1g / L respectively. Wash at 40℃ for 60 minutes and let the washed down dry naturally.

[0060] GPDMS, ethanol, and water were mixed uniformly in a molar ratio of 1:4:12, and then washed down was added (the mass ratio of down to silicone solution was 1:90). The pH of the system was adjusted to 8 with sodium carbonate, and the mixture was heated to 40°C and stirred for 6 hours. After impregnation, the down was separated and air-dried to obtain a fluffy and soft modified down.

[0061] Comparative Example 4

[0062] The difference between Control Example 4 and Example 5 is that only the down is washed.

[0063] Add 1 part down and 30 parts water into a washing machine, and add detergent Ultravon CN and modified amino silicone oil softener at a dosage of 2g / L and 1g / L respectively. Wash at 40℃ for 60 minutes and let the washed down dry naturally.

[0064] Table 1 shows the waterproof performance test results of the down samples obtained in Examples 1-5 and Comparative Examples 1-4.

[0065] Table 1

[0066]

[0067] As can be seen from Table 1, the down sample that was only washed but not waterproofed (Control Example 4) has a very high hygroscopicity. The hygroscopicity of the sample decreased significantly after being treated by the two-step dipping method of the present invention, and the hygroscopicity of the sample was almost unaffected after washing, indicating that the down prepared by the present invention has a good waterproof effect and a high washing fastness. When Control Example 1 was immersed in an alkaline bath, the pH value of the alkaline bath was high, which affected the in-situ film formation of the silicone, and the waterproof effect of the down was poor. Control Example 2 was immersed only under acidic conditions. Under these conditions, the silicone could not form a hydrophobic film well, and the waterproof effect was poor. Control Example 3 was not treated with acid and was directly immersed in an alkaline bath. On the one hand, because the silicone did not undergo hydrolysis and pre-condensation under acidic conditions, the formation of the hydrophobic film on the surface of the down was affected. On the other hand, due to the lack of covalent bonding, the washing fastness was affected.

[0068] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing waterproof modified down, characterized in that: The following steps are involved: (1) Add down, water, detergent and softener into a washing machine and wash the down; (2) mixing epoxysilane, ethanol and water in proportion to obtain a hydrolyzed silanol solution of epoxysilane; (3) dipping the down pretreated in step (1) into the hydrolyzed silanol solution of epoxysilane prepared in step (2), adjusting the pH value of the system to 3-5 with acid, and keeping the dipping warm; The pH value of the system is adjusted to 7.5-9 with alkali, and the impregnation is continued. After the impregnation is completed, the down is separated and naturally dried to obtain waterproof modified down; The epoxysilane is one or both of γ-glycidyloxypropyltrimethoxysilane and γ-glycidyloxypropylmethyldimethoxysilane.

2. The preparation method according to claim 1, wherein: The mass ratio of the down to water is 1:(10-40); the washing temperature is room temperature to 60° C., and the washing time is 30-60 minutes.

3. The preparation method according to claim 1, wherein: The detergent is a nonionic surfactant, and the dosage of the detergent is 2-4 g / L.

4. The preparation method according to claim 1, wherein: The softener is a conventional fluffy softener for textiles, and the amount of the softener is 0.5-2 g / L.

5. The preparation method according to claim 1, wherein: The molar ratio of the epoxysilane, ethanol and water is 1:(2-5):(5-15).

6. The preparation method according to claim 1, wherein: The mass ratio of the down to the hydrolyzed silanol solution of epoxy silane is 1:(80-100).

7. The preparation method according to claim 1, wherein: The acid is hydrochloric acid or acetic acid; the base is sodium carbonate.

8. The preparation method according to claim 1, wherein: The temperature of the heat preservation immersion is 30-60°C.

9. The waterproof modified down prepared according to the preparation method according to any one of claims 1 to 8.

Images