Aqueous silicone polyurethane resin emulsion and preparation and use

Abstract

The present application relates to a kind of aqueous silicone polyurethane resin emulsion and preparation and application, aqueous silicone polyurethane resin includes silicone polyol structural unit, diisocyanate structural unit, anionic hydrophilic structural unit and amine chain extender structural unit;The raw material component for synthesizing aqueous silicone polyurethane resin includes silicone polyol, amine chain extender, carboxylic acid type alcohol chain extender, neutralizing agent and diisocyanate;When preparing, the above raw material component is added to the reaction kettle and is reacted to obtain the product;When using, the viscosity and solid content of aqueous silicone polyurethane resin emulsion are adjusted as the first impregnation slurry, then conventional water-based resin is used to prepare high-softness aqueous polyurethane microfiber base cloth.The long-chain silicone part is introduced into the main chain and branch chain of soft segment of molecular chain segment simultaneously, so that the heat adhesion of resin to fiber is reduced;The aqueous silicone polyurethane resin emulsion prepared has very low heat adhesion performance;The microfiber base cloth obtained when using has soft hand feeling.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of microfiber leather, and relates to a water-based organosilicon polyurethane resin emulsion and preparation and application thereof. BACKGROUND

[0002] At present, most of the microfiber synthetic leather on the market is prepared by using solvent-based polyurethane resin, and the residual and volatilization of organic solvents in the production process pollute the environment and waste resources. With the increasing strictness of environmental protection requirements, the use of organic solvents is severely restricted, and the cost of solvent recovery is also increased. Water-based polyurethane uses water as a solvent, has the advantages of no pollution, safety and reliability, excellent mechanical properties, good compatibility, easy modification and the like. The water-based polyurethane has gradually replaced the solvent type and become an important direction of the development of the polyurethane industry.

[0003] The traditional microfiber processing is a wet coagulation process using solvent-based polyurethane resin. In the wet coagulation stage, water is used to replace the solvent DMF in the resin, so that the polyurethane resin is quickly coagulated. At the same time, many cavities are left when water and DMF are replaced, and gaps are generated between the fibers and the resin, so that the polyurethane is filled in the non-woven fabric in a sponge state, and the obtained microfiber base fabric has a soft hand feeling. At present, in order to achieve the effect of solvent-based microfiber, more researches are focused on the pore and resin distribution of water-based polyurethane. The research on the pore of water-based polyurethane resin includes mechanical foaming, chemical foaming, physical foaming and dissolved pore. The distribution of resin includes acid bath coagulation, salt bath coagulation and resin heat sensitivity.

[0004] The above method solves the pore and resin distribution, but cannot solve the adhesion of water-based polyurethane resin to the fiber. For example, the patent CN114908571A uses a steam condensation technology and a reduced pressure condensing device to reduce the boiling point of water, so that the water condenses into water droplets on the surface of the impregnated non-woven fabric after evaporation, thereby reducing the evaporation speed of water in the impregnated polyester fiber non-woven fabric, and forming a pore structure with uniform pore size and uniform distribution. The method of the patent forms pores and improves the distribution of resin. However, when the water-based polyurethane resin is dried, the polyurethane becomes soft and sticky at high temperature, and is easily adhered to the surface of the fiber, which seriously affects the softness of the microfiber base fabric, especially for high-density microfiber base fabric, which causes the hand feeling to be stiff.

[0005] Therefore, it is of great significance to research a water-based organosilicon polyurethane resin emulsion and preparation and application thereof to solve the problems in the prior art. SUMMARY

[0006] The present application belongs to the technical field of microfiber leather, and relates to a water-based organosilicon polyurethane resin emulsion and preparation and application thereof.

[0007] To achieve the above object, the technical scheme adopted by the present application is as follows:

[0008] An aqueous silicone polyurethane resin emulsion, the aqueous silicone polyurethane resin comprising a silicone polyol structural unit, a diisocyanate structural unit, an anionic hydrophilic structural unit and an amine chain extender structural unit;

[0009] The raw material components participating in the synthesis of the aqueous silicone polyurethane resin refer to the raw material components which can enter into the resin molecular chain through the reaction between active groups. The raw material components participating in the synthesis of the aqueous silicone polyurethane resin include silicone polyol, amine chain extender, carboxylic alcohol chain extender, neutralizing agent and diisocyanate, but do not include polyester or polyether polyester oligomer; the active hydrogen functional groups contained in the silicone polyol, carboxylic alcohol chain extender and amine chain extender react with the NCO functional groups of the diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic alcohol chain extender react with the active end groups in the neutralizing agent to form carboxylic acid salt, constituting the anionic hydrophilic structural unit;

[0010] Among the raw material components participating in the synthesis of the aqueous silicone polyurethane resin, the proportion of the silicone polyol is at least 70wt%, and the content of the silicone polyol is high enough to ensure the effect of preventing adhesion when impregnating low content silicone resin; the number average molecular weight of the silicone polyol is not less than 1750;

[0011] The silicone polyol is a combination of double-end single-hydroxyl polyether modified polysiloxane and single-end double-hydroxyl polysiloxane; the mass ratio of the double-end single-hydroxyl polyether modified polysiloxane and the single-end double-hydroxyl polysiloxane is 1-2:1;

[0012] Double-end single-hydroxyl polyether modified polysiloxane (improve compatibility with conventional resin): refers to the silicone polyol containing one hydroxyl group at each end, and the siloxane is connected in the form of main chain in the polymerization process, and the siloxane molecular structure contains polyether structure;

[0013] Single-end double-hydroxyl polysiloxane (migrate to the outer surface of the resin when the resin is cured at high temperature, increase the amount of silicone on the surface of the resin): refers to the two hydroxyl groups in the silicone polyol being at one end, and the siloxane is connected in the form of branch chain in the polymerization process.

[0014] Introducing other conventional polyester or polyether polyester oligomers will obviously affect the effect of the aqueous silicone polyurethane resin on the adhesion protection of fibers.

[0015] As a preferred technical scheme:

[0016] The aqueous silicone polyurethane resin emulsion has a solid content of 35-50%.

[0017] The waterborne organic silicone polyurethane resin emulsion as described above, the proportion of the amine chain extender in the raw material components participating in the synthesis of the waterborne organic silicone polyurethane resin is 2-3 wt%, the proportion of the carboxylic alcohol chain extender is 1.5-4 wt%, and the molar ratio of the neutralizing agent to the carboxylic alcohol chain extender is 1-1.1:1;

[0018] If the proportion of the carboxylic alcohol chain extender is too small, a stable waterborne polyurethane emulsion cannot be obtained, and if the proportion is too large, the resin after subsequent curing is seriously swollen in water, and the base cloth cannot be processed.

[0019] The waterborne organic silicone polyurethane resin emulsion as described above, the amine chain extender is one or more of ethylenediamine, hexanediamine, isophorone diamine, hydrazine hydrate, diethylenetriamine, propylenediamine and triethylenetetramine, all of which are conventional chain extenders; the carboxylic alcohol chain extender is 2,2-bis(hydroxymethyl)propionic acid or 2,2-bis(hydroxymethyl)butyric acid, the neutralizing agent is triethylamine, and the diisocyanate is one or more of 1,6-hexane diisocyanate, isophorone diisocyanate and dicyclohexyl methane diisocyanate.

[0020] The application also provides a preparation method of the waterborne organic silicone polyurethane resin emulsion as described above, which comprises the following steps:

[0021] (1) Put the organic silicone polyol into a reaction kettle;

[0022] (2) Put the diisocyanate into the reaction kettle, control the reaction temperature at 100-110 DEG C, and until the organic silicone polyol is completely reacted;

[0023] (3) Put the carboxylic alcohol chain extender into the reaction kettle, and keep the temperature at 90-95 DEG C for reaction until the carboxylic alcohol chain extender is completely reacted;

[0024] (4) Put the neutralizing agent into the reaction kettle, and react with the carboxylic alcohol chain extender to completely convert the carboxyl group of the carboxylic alcohol chain extender into a salt;

[0025] (5) Control the temperature in the reaction kettle below 50 DEG C, first put the emulsifier into the reaction kettle and mix uniformly, and then add deionized water to form an emulsion;

[0026] (6) Put the amine chain extender into the reaction kettle, and after the reaction is complete, the waterborne organic silicone polyurethane resin emulsion is obtained.

[0027] The addition of the neutralizing agent makes the carboxylic acid group into a salt, and after salification, the polyurethane resin has ideal hydrophilicity, so that the resin can form a stable polyurethane emulsion. When the polyurethane emulsion is cured during the processing, triethylamine is separated from the molecular chain again, and the salt is converted into a carboxyl group again. At this time, when the cured polyurethane is immersed in water, it does not re-dissolve.

[0028] In the preparation of water-based polyurethane, it is generally necessary to introduce a high-reactivity amine chain extender to increase the molecular weight of the resin, so as to obtain the desired film-forming property, otherwise the resin raw material cannot be used for the preparation of microfiber base cloth.

[0029] As known, the structure of water also contains active hydrogen, and the water content of the system should be controlled in steps (1) to (4) of the polyurethane preparation process. Generally, the water content of the raw materials should be controlled below 300 ppm, and the water removal method and water content control of the relevant raw materials are conventional operations, which will not be described here. The alcohol chain extender is generally used before emulsification, and the amine chain extender (primary amine, secondary amine) with higher reactivity than water needs to be used after emulsification. Steps (5) and (6) need to be carried out at a lower temperature to prevent the occurrence of side reactions such as consumption of NCO in the system by water in the environment.

[0030] The present application also provides a preparation method of a high-softness water-based polyurethane microfiber base cloth, comprising the following steps:

[0031] (1) Preparing a first impregnation slurry: the water-based silicone polyurethane resin emulsion as described in any of the above is prepared to have a viscosity of 800-1200 cps / 25℃ and a solid content of 5-10%; the viscosity is controlled to ensure that the impregnated slurry does not cause uneven distribution of the upper and lower layers of the non-woven fabric due to gravity before coagulation; the solid content of the first impregnation slurry is controlled to be 5-10% to ensure that the silicone polyurethane resin in the water-based polyurethane microfiber base cloth can be fully coated while reducing its content to reduce its influence on the softness and adhesion of the microfiber base cloth.

[0032] (2) First impregnation: the first impregnation slurry is used to impregnate the sea-island fiber non-woven fabric, and the wet pick-up is controlled to be 160-200%; after coagulation, washing and drying, a blank is obtained; a wet pick-up of 160-200% is beneficial to fully wetting and coating the surface of the non-woven fabric; too low a wet pick-up will cause uneven distribution of the resin, and most of the fiber surface will not have resin, and too high a wet pick-up will cause the non-woven fabric surface to present a resin film.

[0033] (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening and drying to obtain a high-softness water-based polyurethane microfiber base cloth; the secondary impregnation uses a conventional polyether type water-based polyurethane resin emulsion as the impregnation material.

[0034] As a preferred technical solution:

[0035] The preparation method of a high-softness water-based polyurethane microfiber base cloth as described above, the coagulation in step (2) refers to coagulation in a 3-5 wt% oxalic acid aqueous solution for 5-10 min.

[0036] The preparation method of the high-softness water-based polyurethane microfiber base cloth as described above, the solid content of the polyether type water-based polyurethane resin emulsion in step (3) is 25-30%, and the viscosity is 800-1200 cps / 25℃.

[0037] The preparation method of the high-softness water-based polyurethane microfiber base cloth as described above, the impregnation liquid rate of step (3) is 150-180%, and after impregnation, drying is carried out in an oven at 120-140℃ to obtain the impregnated island fiber base cloth.

[0038] Invention mechanism

[0039] The water-based organic silicon polyurethane resin prepared by the method has long-chain organic silicon parts introduced into the main chain and the branch chain of the soft segment of the molecular chain segment. The long-chain polyether modified organic silicon segment introduced into the main chain can improve the compatibility of the conventional polyether type polyurethane resin and the water-based organic silicon polyurethane resin. The organic silicon segment introduced into the branch chain migrates to the outer surface of the resin due to incompatibility when the resin is cured at high temperature. Since the surface energy of silicon is low, the resin will not stick to the fiber. Due to the improvement of the main chain and the branch chain, the heat adhesion of the resin to the fiber is reduced.

[0040] In the preparation of the water-based microfiber synthetic leather base cloth, the impregnation of the polyurethane is divided into two times. In the first time, the non-woven fabric is impregnated with the water-based organic silicon polyurethane resin prepared above to form a layer of "anti-sticking film" on the surface of the island fiber. However, due to the slipperiness and low surface energy of such polyurethane, the downstream application of the finished product leather is affected. For example, when the microfiber leather is used in the downstream field such as shoe leather, hot melt adhesive is usually used to combine with other substrates (TPU / EVA material of shoe sole). The adhesion of such water-based organic silicon polyurethane and hot melt adhesive is very poor, which leads to a serious lack of peel strength, and the microfiber leather is easy to fall off. Therefore, the water-based organic silicon polyurethane cannot be directly used as the polyurethane material of the microfiber base cloth. In the second time, the conventional water-based polyurethane is used to fill the gap of the non-woven fabric to improve the peel strength of the microfiber leather and meet the conventional performance requirements.

[0041] The conventional way of polyurethane curing includes high-temperature hot air drying and solidification curing. When the non-woven fabric is impregnated with the water-based organic silicon polyurethane slurry, the solidification liquid is needed to be used for solidification to make the organic silicon polyurethane relatively uniformly coated on the surface of the fiber. When the non-woven fabric is impregnated with the water-based organic silicon polyurethane, the water-based organic silicon polyurethane slurry with low solid content is needed to be used to reduce the content of the organic silicon polyurethane in the final microfiber base cloth as much as possible.

[0042] The second dipping is to dip the conventional water-based polyurethane resin of different types and different concentrations according to the needs of the finished base cloth, and most of the polyurethane of the second dipping is attached to the surface of the silicone polyurethane of the first dipping, so as to avoid the adhesion of the conventional water-based polyurethane to the fiber and ensure the softness of the finished base cloth.

[0043] Advantages:

[0044] (1) The water-based silicone polyurethane resin emulsion has extremely low thermal adhesion, which is beneficial to subsequent base cloth processing.

[0045] (2) The preparation method of the water-based silicone polyurethane resin emulsion introduces long-chain silicone parts into the main chain and side chain of the soft segment of the molecular chain segment, thereby reducing the thermal adhesion of the resin to the fiber.

[0046] (3) The preparation method of the high-softness water-based polyurethane microfiber base cloth includes two times of dipping of polyurethane, which improves the peeling strength and softness of the water-based polyurethane microfiber base cloth, and the prepared water-based polyurethane microfiber base cloth has soft hand feeling. DETAILED DESCRIPTION

[0047] The application will be further described in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the application and not to limit the scope of the application. In addition, it should be understood that those skilled in the art can make various modifications or changes to the application after reading the content taught by the application, and these equivalent forms also fall within the scope of the appended claims of the application.

[0048] The performance indicators of the application involve the following test methods:

[0049] (1) Viscosity: The viscosity of the test liquid is tested using a DV-2T type viscosity meter of Brookfield Company, a 2# rotor is used, the setting is 20 revolutions, and the temperature is kept at 25℃.

[0050] (2) Softness of base cloth: The softness of the microfiber base cloth is determined using a leather softness tester, the model of the leather softness tester is QB-8326 of Shanghai Qingbo Test Equipment Co., Ltd., and the test process is as follows: 1) a test ring with a diameter of 20mm is first used on the test seat of the tester; 2) a metal flat plate provided with the tester is used to adjust the zero of the machine scale; 3) the sample is pressed into the test seat of the tester; 4) after the sample is pressed in, the pointer on the tester will change, and after the pointer is stable, the corresponding value is recorded, the test precision is 0.1mm; 5) the values of three different points are taken as an average value.

[0051] (3) Peeling strength: Preparation of test sample: cut two samples of high-softness waterborne polyurethane microfiber base cloth with a length of 150 mm and a width of 50 mm; apply glue on the surface center of one of the samples, with a coating area of 100 mm long and 50 mm wide, i.e. leaving 25 mm at the top and bottom of the length direction without glue, and the applied glue is 86KN purchased from Nanbao Resin Chemical Factory Co., Ltd., with a coating amount of 130 g / mm 2 , and the other sample is not coated with glue. The two samples are pasted with the coated surface facing each other; the pasted sample is pressed with a 10N pressure roller to make the paste uniform and expel excess air; it is placed in a 140°C oven and baked for 30 min, then taken out and cooled to room temperature. Test the test sample: select ISO 2411 standard and test at a speed of 100 mm / min.

[0052] Some of the substances used in the examples and comparative examples of the present application are as follows:

[0053] (1) The non-woven fabrics used in the examples are all the same, and the selected non-woven fabric is a COPET / PA island fiber with an island mass ratio of 20:80, with a non-woven fabric thickness of 2.3 mm and a density of 0.26 g / cm 3 .

[0054] (2) Conventional emulsifiers can maintain the stability of polyurethane emulsion, and the emulsifiers used in the examples are all fatty alcohol polyoxyethylene ether sodium sulfate.

[0055] (3) Catalysts can accelerate the reaction speed, and the catalysts used in the examples are all purchased from the leading chemical company BICAT 8118 in the United States, and the skilled person in the art can adjust or not add according to the needs.

[0056] (4) Single-end double-hydroxyl polysiloxane, such as Silok 8816 (number average molecular weight 3600), Silok 8826 (number average molecular weight 4500), Silok 8821F31 (number average molecular weight 3100).

[0057] (5) Double-end single-hydroxyl polysiloxane, such as Silok 8815 (number average molecular weight 1750), Silok 8814 (number average molecular weight 3600), Silok 8805 (number average molecular weight 5500).

[0058] (6) Conventional polyether type waterborne polyurethane emulsion all use polyurethane emulsion (solid content is 35%) of JF-PDY-519HY brand of Zhejiang Huafeng Synthetic Resin Co., Ltd., add deionized water to adjust the solid content of the emulsion, and add thickening agent (Dow Chemical brand: RM-8W) to adjust the viscosity of the emulsion. Such conditioning method is a known technology and will not be described here.

[0059] Example 1

[0060] A preparation method of an aqueous silicone polyurethane resin emulsion, the specific steps are as follows:

[0061] (1) Preparation of raw materials:

[0062] Silicone polyol: combination of double-end single-hydroxyl polyether modified polysiloxane (Silok 8815, number average molecular weight 1750) and single-end double-hydroxyl polysiloxane (Silok 8816, number average molecular weight 3600), mass ratio of double-end single-hydroxyl polyether modified polysiloxane and single-end double-hydroxyl polysiloxane is 1:1;

[0063] Diisocyanate; 1,6-hexane diisocyanate;

[0064] Carboxylic alcohol chain extender: 2,2-bis(hydroxymethyl)propionic acid;

[0065] Catalyst: BICAT 8118;

[0066] Neutralizing agent: triethylamine;

[0067] Emulsifier: sodium fatty alcohol polyoxyethylene ether sulfate;

[0068] Amine chain extender: hydrazine hydrate;

[0069] Deionized water;

[0070] In the raw material components, the raw materials participating in the reaction are as follows: the proportion of silicone polyol is 78.1wt%, the proportion of diisocyanate is 15wt%, the proportion of amine chain extender is 2.3wt%, the proportion of carboxylic alcohol chain extender is 2.3wt%, the molar ratio of neutralizing agent to carboxylic alcohol chain extender is 1:1; the mass ratio of catalyst to raw materials participating in the reaction is 0.005, the mass ratio of emulsifier to raw materials participating in the reaction is 0.03, and the mass ratio of deionized water to raw materials participating in the reaction is 1.22;

[0071] (2) Put the silicone polyol into the reaction kettle;

[0072] (3) Put the diisocyanate into the reaction kettle, react at 100°C for 3 hours, until the silicone polyol is completely reacted;

[0073] (4) Put the carboxylic alcohol chain extender into the reaction kettle, and react at 90°C for 3 hours in the presence of catalyst, until the carboxylic alcohol chain extender is completely reacted;

[0074] (5) Put the neutralizing agent into the reaction kettle, and react with the carboxylic alcohol chain extender to completely convert the carboxyl group of the carboxylic alcohol chain extender into salt;

[0075] (6) Control the temperature in the reaction kettle at 50°C, first put into the emulsifier in the reaction kettle and mix evenly, then add deionized water to form an emulsion;

[0076] (7) Put the amine chain extender into the reaction kettle, and after the reaction is complete, the water-based organic silicone polyurethane resin emulsion with a solid content of 45% is obtained.

[0077] The finally prepared water-based organic silicone polyurethane resin comprises organic silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units, and amine chain extender structural units; the active hydrogen functional groups contained in the organic silicone polyol, the carboxylic alcohol chain extender, and the amine chain extender react with the NCO functional groups of the diisocyanate to form a polyurethane chain; the carboxyl groups in the carboxylic alcohol chain extender react with the active end groups in the neutralizing agent to form anionic hydrophilic structural units.

[0078] Comparative Example 1

[0079] A method for preparing a water-based organic silicone polyurethane resin emulsion, which is basically the same as Example 1, except that PTMEG (Mitsubishi Chemical, number average molecular weight 1800) is used to replace the double-end single-hydroxyl polyether modified polysiloxane.

[0080] Comparative Example 2

[0081] A method for preparing a water-based organic silicone polyurethane resin emulsion, which is basically the same as Example 1, except that PTMEG (Mitsubishi Chemical, number average molecular weight 3200) is used to replace the single-end double-hydroxyl polysiloxane.

[0082] Example 2

[0083] A method for preparing a water-based organic silicone polyurethane resin emulsion, the specific steps are as follows:

[0084] (1) Preparation of raw materials:

[0085] Organic silicone polyol: combination of double-end single-hydroxyl polyether modified polysiloxane (Silok 8814, number average molecular weight 3600) and single-end double-hydroxyl polysiloxane (Silok 8826, number average molecular weight 4500), the mass ratio of double-end single-hydroxyl polyether modified polysiloxane and single-end double-hydroxyl polysiloxane is 2:1;

[0086] Diisocyanate; isophorone diisocyanate;

[0087] Carboxylic alcohol chain extender: 2,2-bis(hydroxymethyl) butyric acid;

[0088] Catalyst: BICAT 8118;

[0089] Neutralizing agent: triethylamine;

[0090] Emulsifier: sodium fatty alcohol polyoxyethylene ether sulfate;

[0091] Amine chain extender: hexanediamine;

[0092] Deionized water;

[0093] In the raw material components, the raw materials involved in the reaction are as follows: the proportion of organosilicon polyol is 73.5wt%, the proportion of diisocyanate is 18wt%, the proportion of carboxylic alcohol chain extender is 2.7wt%, the proportion of amine chain extender is 3wt%, the molar ratio of neutralizing agent to carboxylic alcohol chain extender is 1.05:1; the mass ratio of catalyst to raw materials involved in the reaction is 0.005, the mass ratio of emulsifier to raw materials involved in the reaction is 0.03, and the mass ratio of deionized water to raw materials involved in the reaction is 1.5;

[0094] (2) Put the organosilicon polyol into the reaction kettle;

[0095] (3) Put the diisocyanate into the reaction kettle and react at 102℃ for 2.5 hours until the organosilicon polyol is completely reacted;

[0096] (4) Put the carboxylic alcohol chain extender into the reaction kettle and react at 91℃ for 3 hours in the presence of catalyst until the carboxylic alcohol chain extender is completely reacted;

[0097] (5) Put the neutralizing agent into the reaction kettle and react with the carboxylic alcohol chain extender to completely convert the carboxyl group of the carboxylic alcohol chain extender into salt;

[0098] (6) Control the temperature in the reaction kettle at 49℃, first put the emulsifier into the reaction kettle and mix uniformly, then add deionized water to form an emulsion;

[0099] (7) Put the amine chain extender into the reaction kettle, and after the reaction is complete, an aqueous organosilicon polyurethane resin emulsion with a solid content of 40% is obtained.

[0100] The finally prepared aqueous organosilicon polyurethane resin includes organosilicon polyol structural unit, diisocyanate structural unit, anionic hydrophilic structural unit and amine chain extender structural unit; the active hydrogen functional groups contained in organosilicon polyol, carboxylic alcohol chain extender and amine chain extender react with the NCO functional groups of diisocyanate to form polyurethane chain; the carboxyl groups in carboxylic alcohol chain extender react with the active end groups in neutralizing agent to form anionic hydrophilic structural unit.

[0101] Example 3

[0102] A preparation method of an aqueous organosilicon polyurethane resin emulsion, the specific steps are as follows:

[0103] (1) Preparation of raw materials:

[0104] Silicone polyol: combination of double-end single-hydroxyl polyether modified polysiloxane (Silok 8805, number average molecular weight 5500) and single-end double-hydroxyl polysiloxane (Silok 8821F31, number average molecular weight 3100), mass ratio of double-end single-hydroxyl polyether modified polysiloxane and single-end double-hydroxyl polysiloxane being 1.5:1;

[0105] Diisocyanate; dicyclohexylmethane diisocyanate;

[0106] Carboxylic alcohol chain extender: 2,2-bis(hydroxymethyl)propionic acid;

[0107] Catalyst: BICAT 8118;

[0108] Neutralizer: triethylamine;

[0109] Emulsifier: sodium fatty alcohol polyoxyethylene ether sulfate;

[0110] Amine chain extender: isophorone diamine;

[0111] Deionized water;

[0112] In the raw material components, the raw materials participating in the reaction are as follows: the proportion of silicone polyol is 70.6wt%, the proportion of diisocyanate is 19wt%, the proportion of carboxylic alcohol chain extender is 4wt%, the proportion of amine chain extender is 2wt%, the molar ratio of neutralizer to carboxylic alcohol chain extender is 1.1:1; the mass ratio of catalyst to raw materials participating in the reaction is 0.005, the mass ratio of emulsifier to raw materials participating in the reaction is 0.03, and the mass ratio of deionized water to raw materials participating in the reaction is 1.86;

[0113] (2) Put the silicone polyol into the reaction kettle;

[0114] (3) Put the diisocyanate into the reaction kettle and react at 108℃ for 2.5 hours until the silicone polyol is completely reacted;

[0115] (4) Put the carboxylic alcohol chain extender into the reaction kettle and react at 93℃ for 2.5 hours in the presence of catalyst until the carboxylic alcohol chain extender is completely reacted;

[0116] (5) Put the neutralizer into the reaction kettle and react with the carboxylic alcohol chain extender to completely convert the carboxyl group of the carboxylic alcohol chain extender into salt;

[0117] (6) Control the temperature in the reaction kettle at 48℃, first put the emulsifier into the reaction kettle and mix uniformly, then add deionized water to form an emulsion;

[0118] (7) Put the amine chain extender into the reaction kettle, and after the reaction is complete, an aqueous silicone polyurethane resin emulsion with a solid content of 35% is obtained.

[0119] The finally prepared aqueous silicone polyurethane resin comprises silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units and amine chain extender structural units; the active hydrogen functional groups contained in the silicone polyol, the carboxylic alcohol chain extender and the amine chain extender react with the NCO functional groups of the diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic alcohol chain extender react with the active end groups in the neutralizing agent to form the anionic hydrophilic structural units.

[0120] Example 4

[0121] A preparation method of an aqueous silicone polyurethane resin emulsion, the specific steps are as follows:

[0122] (1) Preparation of raw materials:

[0123] Silicone polyol: combination of double-end single-hydroxyl polyether modified polysiloxane (Silok 8815, number average molecular weight 1750) and single-end double-hydroxyl polysiloxane (Silok 8816, number average molecular weight 3600), mass ratio of double-end single-hydroxyl polyether modified polysiloxane to single-end double-hydroxyl polysiloxane is 1.5:1;

[0124] Diisocyanate; 1,6-hexane diisocyanate and isophorone diisocyanate with a mass ratio of 1:1;

[0125] Carboxylic alcohol chain extender: 2,2-bis(hydroxymethyl)butyric acid;

[0126] Catalyst: BICAT 8118;

[0127] Neutralizing agent: triethylamine;

[0128] Emulsifier: sodium fatty alcohol polyoxyethylene ether sulfate;

[0129] Amine chain extender: ethylenediamine;

[0130] Deionized water;

[0131] In the raw material components, the raw materials participating in the reaction are as follows: the proportion of silicone polyol is 79wt%, the proportion of diisocyanate is 16wt%, the proportion of carboxylic alcohol chain extender is 1.5wt%, the proportion of amine chain extender is 2wt%, the molar ratio of neutralizing agent to carboxylic alcohol chain extender is 1:1; the mass ratio of catalyst to raw materials participating in the reaction is 0.005, the mass ratio of emulsifier to raw materials participating in the reaction is 0.03, and the mass ratio of deionized water to raw materials participating in the reaction is 1;

[0132] (2) Put the silicone polyol into the reaction kettle;

[0133] (3) Put the diisocyanate into the reaction kettle and react for 2 hours at 110°C until the silicone polyol is completely reacted;

[0134] (4) Put the carboxylic alcohol chain extender into the reaction kettle and react for 2 hours at 95°C until the carboxylic alcohol chain extender is completely reacted in the presence of a catalyst;

[0135] (5) Put the neutralizing agent into the reaction kettle and react with the carboxylic alcohol chain extender to completely convert the carboxyl groups of the carboxylic alcohol chain extender into salts;

[0136] (6) Control the temperature in the reaction kettle at 45°C, first put the emulsifier into the reaction kettle and mix uniformly, and then add deionized water to form an emulsion;

[0137] (7) Put the amine chain extender into the reaction kettle, and after the reaction is complete, an aqueous silicone polyurethane resin emulsion with a solid content of 50% is obtained.

[0138] The finally obtained aqueous silicone polyurethane resin comprises silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units, and amine chain extender structural units; the active hydrogen functional groups contained in the silicone polyol, the carboxylic alcohol chain extender, and the amine chain extender react with the NCO functional groups of the diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic alcohol chain extender react with the active end groups in the neutralizing agent to form anionic hydrophilic structural units.

[0139] Example 5

[0140] A preparation method of a high-softness aqueous polyurethane microfiber base fabric, the specific steps are as follows:

[0141] (1) Prepare a first impregnation slurry: adjust the aqueous silicone polyurethane resin emulsion of Example 1 to a viscosity of 800 cps / 25°C and a solid content of 5%;

[0142] (2) First impregnation: impregnate the sea-island fiber non-woven fabric with the first impregnation slurry, control the liquid retention rate to be 160%, and then coagulate in a 3 wt% oxalic acid aqueous solution for 10 minutes, and then wash with water and dry to obtain a blank;

[0143] (3) Perform secondary impregnation, 95°C fiber opening, and 130°C drying on the blank obtained in step (2) to obtain a high-softness aqueous polyurethane microfiber base fabric; wherein the secondary impregnation uses a conventional polyether type aqueous polyurethane resin emulsion with a solid content of 25% and a viscosity of 800 cps / 25°C as the impregnation material, the liquid retention rate of impregnation is 160%, and the impregnated sea-island fiber base fabric is obtained after drying in a 140°C oven.

[0144] The softness of the high-softness waterborne polyurethane microfiber base cloth prepared finally is 3.8 mm, and the peel strength is 140 N / 2.54 cm.

[0145] Comparative Example 3

[0146] A method for preparing a waterborne polyurethane microfiber base cloth, which is basically the same as that of Example 5, except that the waterborne silicone polyurethane resin emulsion prepared in Comparative Example 1 is used to replace the waterborne silicone polyurethane resin emulsion of Example 1.

[0147] The softness of the high-softness waterborne polyurethane microfiber base cloth prepared finally is 2.8 mm, and the peel strength is 142 N / 2.54 cm.

[0148] Comparing Comparative Example 3 with Example 5, it can be found that the softness of Comparative Example 3 is obviously worse, which is because the waterborne silicone polyurethane resin emulsion prepared in Comparative Example 1 introduces polyether soft segments in the molecular structure, so that the effect of the emulsion on preventing fiber adhesion is not good, and thus the softness is obviously decreased.

[0149] Comparative Example 4

[0150] A method for preparing a waterborne polyurethane microfiber base cloth, which is basically the same as that of Example 5, except that the waterborne silicone polyurethane resin emulsion prepared in Comparative Example 2 is used to replace the waterborne silicone polyurethane resin emulsion of Example 1.

[0151] The softness of the high-softness waterborne polyurethane microfiber base cloth prepared finally is 2.5 mm, and the peel strength is 158 N / 2.54 cm.

[0152] Comparing Comparative Example 4 with Example 5, it can be found that the softness of Comparative Example 4 is obviously worse, which is because the waterborne silicone polyurethane resin emulsion prepared in Comparative Example 2 introduces polyether soft segments, so that the effect of the emulsion on preventing fiber adhesion is not good, and thus the softness is obviously decreased.

[0153] Comparative Example 5

[0154] A method for preparing a waterborne polyurethane microfiber base cloth, which is basically the same as that of Example 5, except that the operations of steps (1) and (2) are omitted, and secondary immersion is directly performed, and the waterborne silicone polyurethane resin emulsion prepared in Comparative Example 1 is used to replace the conventional polyether type waterborne polyurethane resin emulsion.

[0155] The softness of the high-softness waterborne polyurethane microfiber base cloth prepared finally is 3.6 mm, and the peel strength is 82 N / 2.54 cm.

[0156] Comparing Example 5 and Comparative Example 5, it can be found that the peeling strength of Comparative Example 5 is significantly deteriorated, because the waterborne organosilicon polyurethane resin prepared in Comparative Example 1 contains a large amount of organosilicon structure in the molecular structure, and such resin directly used to replace the conventional polyester or polyether type polyurethane impregnating solution can effectively improve the softness, but the performance is lost due to too large proportion of organosilicon structure in the polyurethane molecular chain, and the peeling strength is significantly decreased.

[0157] Comparative Example 6

[0158] A method for preparing a high-softness waterborne polyurethane microfiber base cloth, which is basically the same as Example 5, except that the operations of steps (1) and (2) are omitted, and secondary impregnation is directly performed, and the waterborne organosilicon polyurethane resin emulsion prepared in Comparative Example 2 is used to replace the conventional polyether type waterborne polyurethane resin emulsion.

[0159] The softness of the finally prepared high-softness waterborne polyurethane microfiber base cloth is 3.3 mm, and the peeling strength is 88 N / 2.54 cm.

[0160] Comparing Example 6 and Example 5, it can be found that the softness and peeling strength of Comparative Example 5 are both significantly deteriorated, because the waterborne organosilicon polyurethane resin prepared in Comparative Example 2 contains a large amount of organosilicon structure in the molecular structure, and such resin directly used to replace the conventional polyester or polyether type polyurethane impregnating solution can effectively improve the softness, but the performance is lost due to too large proportion of organosilicon structure in the polyurethane molecular chain, and the peeling strength is significantly decreased.

[0161] Example 6

[0162] A method for preparing a high-softness waterborne polyurethane microfiber base cloth, the specific steps are as follows:

[0163] (1) preparing a first impregnating slurry: the waterborne organosilicon polyurethane resin emulsion of Example 2 is prepared to have a viscosity of 900 cps / 25℃ and a solid content of 6%;

[0164] (2) primary impregnation: the first impregnating slurry is used to impregnate the sea-island fiber non-woven cloth, and the liquid retention rate is controlled to be 170%, and then the sea-island fiber non-woven cloth is coagulated in 3.5 wt% oxalic acid aqueous solution for 9 min, and then washed with water and dried to obtain a blank;

[0165] (3) the blank obtained in step (2) is subjected to secondary impregnation, 96℃ fiber opening and 125℃ drying to obtain a high-softness waterborne polyurethane microfiber base cloth; wherein the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 25% and a viscosity of 900 cps / 25℃ as the impregnating material, the liquid retention rate of impregnation is 150%, and the impregnated sea-island fiber base cloth is obtained after impregnation and drying in a 135℃ oven.

[0166] The softness of the high-softness waterborne polyurethane microfiber base fabric prepared finally is 4 mm, and the peel strength is 132 N / 2.54 cm.

[0167] Example 7

[0168] A preparation method of a high-softness waterborne polyurethane microfiber base fabric, the specific steps being as follows:

[0169] (1) Preparation of the first impregnation slurry: the waterborne silicone polyurethane resin emulsion of Example 3 is prepared to have a viscosity of 1100 cps / 25℃ and a solid content of 7%;

[0170] (2) First impregnation: the first impregnation slurry is used to impregnate the sea-island fiber non-woven fabric, the liquid retention rate being controlled to be 180%, and then the impregnated fabric is coagulated in 4 wt% oxalic acid solution for 7 min, and then washed with water and dried in sequence to obtain a blank;

[0171] (3) The blank obtained in step (2) is subjected to secondary impregnation, 98℃ fiber splitting and 125℃ drying to obtain the high-softness waterborne polyurethane microfiber base fabric; the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 26% and a viscosity of 1100 cps / 25℃ as the impregnation material, the liquid retention rate of impregnation being 170%, and the impregnated sea-island fiber base fabric is obtained after drying in a 130℃ oven.

[0172] The softness of the high-softness waterborne polyurethane microfiber base fabric prepared finally is 4 mm, and the peel strength is 132 N / 2.54 cm.

[0173] Example 8

[0174] A preparation method of a high-softness waterborne polyurethane microfiber base fabric, the specific steps being as follows:

[0175] (1) Preparation of the first impregnation slurry: the waterborne silicone polyurethane resin emulsion of Example 4 is prepared to have a viscosity of 1200 cps / 25℃ and a solid content of 10%;

[0176] (2) First impregnation: the first impregnation slurry is used to impregnate the sea-island fiber non-woven fabric, the liquid retention rate being controlled to be 200%, and then the impregnated fabric is coagulated in 5 wt% oxalic acid solution for 5 min, and then washed with water and dried in sequence to obtain a blank;

[0177] (3) The blank obtained in step (2) is subjected to secondary impregnation, 100℃ fiber splitting and 120℃ drying to obtain the high-softness waterborne polyurethane microfiber base fabric; the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 30% and a viscosity of 1200 cps / 25℃ as the impregnation material, the liquid retention rate of impregnation being 180%, and the impregnated sea-island fiber base fabric is obtained after drying in a 120℃ oven.

[0178] The softness of the prepared high-softness waterborne polyurethane microfiber base cloth is 4.2 mm, and the peel strength is 128 N / 2.54 cm.

Claims

1. A water-based organosilicon polyurethane resin emulsion, characterized in that: The waterborne organosilicon polyurethane resin comprises organosilicon polyol structural units, diisocyanate structural units, anionic hydrophilic structural units, and amine chain extender structural units. The raw material components involved in the synthesis of the waterborne organosilicon polyurethane resin include organosilicon polyol, amine chain extender, carboxylic acid alcohol chain extender, neutralizer, and diisocyanate; the active hydrogen functional groups contained in the organosilicon polyol, carboxylic acid alcohol chain extender, and amine chain extender react with the NCO functional groups of diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic acid alcohol chain extender react with the active end groups in the neutralizer to form anionic hydrophilic structural units; In the raw material components involved in the synthesis of the waterborne organosilicon polyurethane resin, the proportion of organosilicon polyol is at least 70 wt%, the proportion of carboxylic acid alcohol chain extender is 1.5~4 wt%, and the number average molecular weight of organosilicon polyol is not less than 1750. The organosilicon polyol is a combination of double-terminated monohydroxy polyether modified polysiloxane and single-terminated dihydroxy polysiloxane; the mass ratio of double-terminated monohydroxy polyether modified polysiloxane to single-terminated dihydroxy polysiloxane is 1~2:

1.

2. The aqueous organosilicon polyurethane resin emulsion according to claim 1, characterized in that, The solid content of the aqueous organosilicon polyurethane resin emulsion is 35-50%.

3. The aqueous organosilicon polyurethane resin emulsion according to claim 1, characterized in that, In the raw material components involved in the synthesis of the waterborne organosilicon polyurethane resin, the proportion of amine chain extender is 2-3 wt%, and the molar ratio of neutralizer to carboxylic acid alcohol chain extender is 1-1.1:

1.

4. The aqueous organosilicon polyurethane resin emulsion according to claim 1, characterized in that, The amine chain extender is one or more of ethylenediamine, hexamethylenediamine, isophorone diamine, hydrazine hydrate, diethylenetriamine, propylenediamine, and triethylenetetramine; the carboxylic acid alcohol chain extender is 2,2-bis(hydroxymethyl)propionic acid or 2,2-bis(hydroxymethyl)butyric acid; the neutralizing agent is triethylamine; and the diisocyanate is one or more of 1,6-hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane diisocyanate.

5. A method for preparing an aqueous organosilicon polyurethane resin emulsion as described in any one of claims 1 to 4, characterized in that... Includes the following steps: (1) Add the organosilicon polyol to the reactor; (2) Add diisocyanate to the reactor and control the reaction temperature at 100~110℃ until the organosilicon polyol reacts completely; (3) Add carboxylic acid alcohol chain extender to the reaction vessel and keep it at 90~95℃ until the carboxylic acid alcohol chain extender has completely reacted; (4) Add a neutralizing agent to the reaction vessel to react with the carboxylic acid alcohol chain extender, so that the carboxyl group of the carboxylic acid alcohol chain extender is completely converted into salt; (5) Control the temperature inside the reactor to below 50°C. First, add the emulsifier into the reactor and mix it evenly, then add deionized water to form an emulsion. (6) Add an amine chain extender to the reaction vessel and after the reaction is complete, the water-based organosilicon polyurethane resin emulsion is obtained.

6. A method for preparing a highly flexible waterborne polyurethane microfiber base fabric, characterized in that... Includes the following steps: (1) Preparation of the first impregnation slurry: The waterborne silicone polyurethane resin emulsion according to any one of claims 1 to 4 is prepared to a viscosity of 800 to 1200 cps / 25℃ and a solid content of 5 to 10%; (2) First impregnation: The island fiber nonwoven fabric is impregnated with the first impregnation slurry, and the liquid content is controlled at 160~200%. After solidification, washing and drying, the preform is obtained. (3) The preform obtained in step (2) is subjected to secondary impregnation, fiber opening and drying to obtain a highly flexible waterborne polyurethane microfiber base fabric; the secondary impregnation uses polyether-type waterborne polyurethane resin emulsion as impregnating material.

7. The method for preparing a highly flexible waterborne polyurethane microfiber base fabric according to claim 6, characterized in that, In step (2), coagulation refers to coagulating in a 3-5 wt% oxalic acid aqueous solution for 5-10 minutes.

8. The method for preparing a highly flexible waterborne polyurethane microfiber base fabric according to claim 6, characterized in that, In step (3), the solid content of the polyether-type waterborne polyurethane resin emulsion is 25-30%, and the viscosity is 800-1200 cps / 25℃.

9. The method for preparing a highly flexible waterborne polyurethane microfiber base fabric according to claim 6, characterized in that, Step (3) The liquid content of the impregnation is 150-180%, and after impregnation, it is dried in an oven at 120-140℃ to obtain the impregnated island fiber base fabric.