Water-based organic silicon polyurethane resin emulsion as well as preparation and application thereof

Abstract

The invention relates to a water-based organic silicon polyurethane resin emulsion as well as preparation and application thereof. The water-based organic silicon polyurethane resin comprises an organic silicon polyol structural unit, a diisocyanate structural unit, an anionic hydrophilic structural unit and an amine chain extender structural unit, the water-based organic silicon polyurethane resin is prepared from the following raw material components: organic silicon polyol, an amine chain extender, a carboxylic acid type alcohol chain extender, a neutralizer and diisocyanate. During preparation, the raw material components are added into a reaction kettle to react to prepare the product. During application, the viscosity and the solid content of a water-based organic silicon polyurethane resin emulsion are adjusted to serve as first impregnation slurry, and then the first impregnation slurry is impregnated with conventional water-based resin to prepare the high-flexibility water-based polyurethane microfiber base cloth. According to the invention, a long-chain organic silicon part is introduced into a main chain and a branch chain of a soft segment of a molecular chain segment at the same time, so that the thermal adhesion of resin to fibers is reduced; the prepared water-based organic silicon polyurethane resin emulsion has extremely low thermal adhesion performance; the microfiber base cloth obtained during application is soft in hand feeling.

Description

Technical Field

[0001] The invention belongs to the technical field of ultra-fine leather and relates to a water-based organosilicon polyurethane resin emulsion and its preparation and application. Background Art

[0002] At present, most of the microfiber synthetic leathers on the market are prepared by solvent-based polyurethane resins. The residual and volatilization of organic solvents in the production process not only pollutes the environment but also wastes resources. With the increasingly stringent environmental protection requirements, the use of organic solvents has been severely restricted, and the cost of solvent recovery has increased. Water-based polyurethane uses water as a solvent and has the advantages of no pollution, safety and reliability, excellent mechanical properties, good compatibility, and easy modification. Water-based polyurethane resins have gradually replaced solvent-based ones and become an important direction for the development of the polyurethane industry.

[0003] Traditional microfiber processing uses a wet coagulation process of solvent-based polyurethane resin. During the wet coagulation stage, water is used to displace the solvent DMF in the resin, causing the polyurethane resin to solidify quickly. At the same time, many voids will be left when water and DMF are replaced, and gaps will be generated between the fiber and the resin, so that the polyurethane is filled in the non-woven fabric in a sponge state, and the resulting microfiber base fabric feels soft. At present, in order to achieve the effect of solvent-based microfiber, water-based microfiber is mostly studying the distribution of pores and resins. The research on the pores of water-based polyurethane resins includes mechanical foaming, chemical foaming, physical foaming, and dissolution into pores. For the distribution of resins, methods include acid bath coagulation, salt bath coagulation, and resin thermal sensitivity.

[0004] The above methods solve the problem of pores and resin distribution, but fail to solve the problem of the adhesion of waterborne polyurethane resin to fibers. For example, patent CN114908571A uses steam condensation technology and decompression condensation equipment 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 rate of water in the impregnated polyester fiber non-woven fabric, thereby forming a pore structure with uniform pore size and uniform distribution. The method of this patent produces pores and improves the distribution of resin. However, when the waterborne polyurethane resin is dried, the polyurethane becomes soft and sticky at high temperature, and it is very easy to adhere to the surface of the fiber, which seriously affects the softness of the microfiber base cloth, especially for high-density microfiber base cloth, which will cause a stiff feel.

[0005] Therefore, it is of great significance to study a water-based silicone polyurethane resin emulsion and its preparation and application to solve the problems existing in the prior art. Summary of the invention

[0006] The purpose of the present invention is to solve the problems existing in the prior art and to provide a water-based organosilicon polyurethane resin emulsion and its preparation and application.

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

[0008] A water-based organosilicon polyurethane resin emulsion, wherein the water-based organosilicon polyurethane resin comprises an organosilicon polyol structural unit, a diisocyanate structural unit, an anionic hydrophilic structural unit and an amine chain extender structural unit;

[0009] The raw material components involved in the synthesis of the waterborne silicone polyurethane resin refer to the raw material components that can enter the resin molecular chain through reactions between active groups. The raw material components involved in the synthesis of the waterborne silicone polyurethane resin include silicone polyols, amine chain extenders, carboxylic acid alcohol chain extenders, neutralizers and diisocyanates, but do not include polyester or polyether polyester oligomers; the active hydrogen functional groups contained in silicone polyols, carboxylic acid alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanates to form polyurethane chains; the carboxyl groups in carboxylic acid alcohol chain extenders react with the active end groups in the neutralizer to form carboxylates, forming anionic hydrophilic structural units;

[0010] Among the raw material components involved in the synthesis of the water-based silicone polyurethane resin, the proportion of silicone polyol is at least 70wt%, and the content of 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 organosilicon polyol is a combination of a double-terminal monohydroxyl polyether-modified polysiloxane and a single-terminal dihydroxyl polysiloxane; the mass ratio of the double-terminal monohydroxyl polyether-modified polysiloxane to the single-terminal dihydroxyl polysiloxane is 1 to 2:1;

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

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

[0014] The introduction of other conventional polyester or polyether polyester oligomers will significantly affect the effect of the waterborne silicone polyurethane resin on fiber adhesion protection.

[0015] As the preferred technical solution:

[0016] The aqueous organosilicon polyurethane resin emulsion as described above has a solid content of 35-50%.

[0017] The aqueous silicone polyurethane resin emulsion as described above, wherein the raw material components involved in the synthesis of the aqueous silicone polyurethane resin include 2-3wt% of the amine chain extender, 1.5-4wt% of the carboxylic acid alcohol chain extender, and a molar ratio of the neutralizer to the carboxylic acid alcohol chain extender of 1-1.1:1;

[0018] If the proportion of carboxylic acid alcohol chain extenders is too small, a stable water-based polyurethane emulsion cannot be obtained. If the proportion is too large, the resin after subsequent curing will swell severely in water, making it impossible to process the base fabric.

[0019] In the aqueous silicone polyurethane resin emulsion as described above, the amine chain extender is one or more of ethylenediamine, hexamethylenediamine, isophoronediamine, hydrazine hydrate, diethylenetriamine, propylenediamine and triethylenetetramine, all of which are conventional chain extenders; the carboxylic acid type 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.

[0020] The present invention also provides a method for preparing a water-based silicone polyurethane resin emulsion as described in any one of the above items, comprising the following steps:

[0021] (1) putting organosilicon polyol into a reaction kettle;

[0022] (2) adding diisocyanate into a reaction kettle, and controlling the reaction temperature at 100-110° C. until the organosilicon polyol is completely reacted;

[0023] (3) adding a carboxylic acid type alcohol chain extender into the reaction kettle, and keeping the temperature at 90-95° C. for reaction until the carboxylic acid type alcohol chain extender is completely reacted;

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

[0025] (5) controlling the temperature in the reactor to be below 50° C., first adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion;

[0026] (6) Adding an amine chain extender into the reaction kettle, and obtaining the water-based silicone polyurethane resin emulsion after the reaction is complete.

[0027] The addition of the neutralizer turns the carboxylic acid group into a salt. Only after the salt is formed, the polyurethane resin has an ideal hydrophilicity, so that the resin can form a stable polyurethane emulsion. When the polyurethane emulsion solidifies during the processing, the triethylamine is separated from the molecular chain again, and the salt is converted back into a carboxyl group. At this time, when the solidified polyurethane is immersed in water again, it will no longer dissolve.

[0028] When preparing waterborne polyurethane, it is usually necessary to introduce a highly reactive amine chain extender to increase the molecular weight of the resin and thereby obtain ideal film-forming properties. Otherwise, the resin raw material cannot be used in the preparation of microfiber-based fabrics.

[0029] As is well known, water also contains active hydrogen in its structure. In the steps (1) to (4) of the polyurethane preparation process, the water content of the system should be controlled. It is usually necessary to control the water content of the raw materials to be less than 300 ppm. The dehydration method and water content control of the relevant raw materials are conventional operations and will not be described in detail here. Alcohol chain extenders are generally used before emulsification, while amine chain extenders (primary amines, secondary amines) with higher reaction activity than water are required after emulsification, and steps (5) and (6) need to control the reaction temperature at a lower temperature to prevent the occurrence of side reactions such as the NCO in the system being consumed by water in the environment.

[0030] The present invention also provides a method for preparing a highly soft waterborne polyurethane microfiber-based fabric, comprising the following steps:

[0031] (1) Preparing the first impregnation slurry: prepare the water-based silicone polyurethane resin emulsion as described in any of the above items to a viscosity of 800-1200cps / 25°C and a solid content of 5-10%; the viscosity needs to be controlled so that the slurry after impregnation will not be unevenly distributed between the upper and lower layers of the non-woven fabric due to the influence of gravity before passing through the coagulation liquid; the solid content of the first impregnation slurry should be controlled at 5-10% to ensure that the silicone polyurethane resin in the water-based polyurethane microfiber base fabric can be fully coated at the target liquid carrying rate, while reducing its content to reduce its influence on the velvet feel and adhesion of the microfiber base fabric.

[0032] (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, and the liquid carrying rate is controlled to be 160-200%, and the blank is obtained after coagulation, water washing and drying in sequence; the liquid carrying rate is controlled within the range of 160-200%, which is beneficial to fully impregnate and coat the surface of the nonwoven fiber; too little liquid carrying rate will lead to uneven resin distribution, and most of the fiber surfaces will have no resin, and too much liquid carrying rate will lead to a resin film on the surface of the nonwoven fabric.

[0033] (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening and drying to obtain a highly soft waterborne polyurethane microfiber base fabric; the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion as an impregnating material.

[0034] As the preferred technical solution:

[0035] In the method for preparing a highly soft water-based polyurethane microfiber-based fabric as described above, the coagulation in step (2) refers to coagulation in a 3-5wt% oxalic acid aqueous solution for 5-10 minutes.

[0036] In the method for preparing a highly soft water-based polyurethane microfiber-based fabric 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°C.

[0037] In the method for preparing a highly soft waterborne polyurethane microfiber fabric as described above, the liquid carrying rate of the impregnation in step (3) is 150-180%, and after impregnation, the impregnated sea island fiber fabric is dried in an oven at 120-140°C to obtain the impregnated sea island fiber fabric.

[0038] Invention mechanism

[0039] The waterborne organosilicon polyurethane resin prepared by the present invention introduces long-chain organosilicon parts into the main chain and the side chain of the soft segment of the molecular chain segment. The introduction of long-chain polyether-modified organosilicon segments into the main chain can improve the compatibility between conventional polyether-type polyurethane resin and the waterborne organosilicon polyurethane resin; the introduction of long-chain organosilicon segments into the side chains, when the resin is cured at high temperature, the organosilicon segments migrate to the outer surface of the resin due to incompatibility, and the resin will not adhere to the fiber due to the low surface energy of silicon. It is precisely because of the above improvements in the main chain and the side chains that the thermal adhesion of the resin to the fiber is reduced.

[0040] When preparing the water-based microfiber synthetic leather base fabric, the impregnation of polyurethane is divided into two impregnations. The impregnation resin used for the first non-woven fabric impregnation is the water-based silicone polyurethane resin prepared above, so that the surface of the sea island fiber is coated with a layer of "anti-adhesive film". However, this type of polyurethane affects the downstream application of the subsequent finished leather due to its smoothness and low surface energy. For example, when microfiber leather is used in downstream fields such as shoe leather, it is usually necessary to use hot melt adhesive to compound with other substrates (shoe sole TPU / EVA material). This type of water-based silicone polyurethane has extremely poor adhesion to hot melt adhesive, resulting in serious lack of peeling strength. The microfiber leather is easy to fall off. Therefore, it is usually not directly used as a polyurethane material for microfiber base fabrics; the second impregnation uses conventional water-based polyurethane to fill the gaps in the non-woven fabric, which can improve the peeling strength of the microfiber leather so that it meets conventional performance requirements.

[0041] Conventional methods of polyurethane curing include high-temperature hot air drying curing and coagulation curing. When non-woven fabrics are impregnated with water-based silicone polyurethane slurry, it is necessary to use a coagulation liquid coagulation method so that the silicone polyurethane is relatively evenly coated on the fiber surface; when non-woven fabrics are impregnated with water-based silicone polyurethane, it is necessary to use a low-solid content water-based silicone polyurethane slurry to minimize the content of silicone polyurethane in the final microfiber base fabric.

[0042] The second impregnation is carried out according to the needs of the finished base fabric, and then impregnated with conventional water-based polyurethane resins of different types and concentrations. Most of the polyurethane impregnated in the second impregnation is attached to the surface of the silicone polyurethane impregnated in the first impregnation, thereby avoiding the adhesion of conventional water-based polyurethane to the fiber and ensuring the softness of the finished base fabric.

[0043] Beneficial effects:

[0044] (1) The aqueous silicone polyurethane resin emulsion of the present invention has extremely low thermal adhesion performance, which is beneficial to the subsequent base fabric processing.

[0045] (2) The present invention provides a method for preparing a water-based silicone polyurethane resin emulsion, which introduces long-chain silicone parts into the main chain and the 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 present invention provides a method for preparing a highly soft water-based polyurethane microfiber fabric. The impregnation with polyurethane is divided into two impregnations, which improves the peel strength and softness of the water-based polyurethane microfiber fabric. The prepared water-based polyurethane microfiber fabric has a soft feel. DETAILED DESCRIPTION

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

[0048] The test methods involved in the performance indicators of the present invention are as follows:

[0049] (1) Viscosity: The viscosity of the liquid to be tested was measured using a Brookfield DV-2T viscometer with a 2# rotor set at 20 rpm and a temperature of 25°C.

[0050] (2) Softness of base fabric: The softness of microfiber base fabric was measured using a leather softness tester, model: QB-8326 from Shanghai Qingbo Testing Equipment Co., Ltd. The test process is as follows: 1) Use a test ring with a diameter of 20 mm on the test seat of the test machine; 2) Use the metal plate equipped with the machine to adjust the machine dial to zero; 3) Press the sample into the test seat of the test machine; 4) After the sample is pressed in, the pointer on the test machine will change. After the pointer stabilizes, record its corresponding value. The test accuracy is 0.1 mm; 5) Take the average value of the values ​​at three different test points.

[0051] (3) Peel strength: Preparation of test samples: Cut two samples of high-softness water-based polyurethane microfiber fabric with a length of 150 mm and a width of 50 mm; apply glue to the center of the surface of one of the samples, with a coating area of ​​100 mm in length and 50 mm in width, that is, leaving 25 mm uncoated in the upper and lower length directions. The glue applied was purchased from 86KN of Nanbao Resin Chemical Factory Co., Ltd., and the coating amount was 130 g / mm 2 , the other sample is not coated with glue, and the two samples are pasted on the glued surface; the pasted samples are squeezed with a 10N pressure roller to make the pasting uniform and exhaust excess air; put them into a 140℃ oven, bake for 30 minutes, then take them out and cool them to room temperature. Test sample test: select IS0 2411 standard and test at a speed of 100mm / min.

[0052] The information of some substances used in the examples and comparative examples of the present invention are as follows:

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

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

[0055] (3) Catalysts can accelerate the reaction rate. The catalysts used in the examples were purchased from BICAT 8118, a leading chemical company in the United States. Those skilled in the art can adjust or not add the catalysts according to their needs.

[0056] (4) Single-end dihydroxy 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-terminal monohydroxyl polyether modified 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-based waterborne polyurethane emulsions are all made from Zhejiang Huafeng Synthetic Resin Co., Ltd., with a polyurethane emulsion brand: JF-PDY-519HY (solid content of 35%). Deionized water is added to adjust the solid content of the emulsion, and a thickener (Dow Chemical brand: RM-8W) is added to adjust the viscosity of the emulsion. This type of modulation method is a well-known technology and will not be described in detail here.

[0059] Example 1

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

[0061] (1) Preparation of raw materials:

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

[0063] Diisocyanate; 1,6-hexanediisocyanate;

[0064] Carboxylic acid type 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] Among the raw material components, the raw materials participating in the reaction are as follows: the proportion of organosilicon polyol is 78.1wt%, the proportion of diisocyanate is 15wt%, the proportion of amine chain extender is 2.3wt%, the proportion of carboxylic acid type alcohol chain extender is 2.3wt%, and the molar ratio of neutralizer to carboxylic acid type 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) adding organosilicon polyol into a reaction kettle;

[0072] (3) adding diisocyanate into a reaction kettle and reacting at 100° C. for 3 hours until the organosilicon polyol is completely reacted;

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

[0074] (5) adding a neutralizing agent into the reaction kettle to react with the carboxylic acid type alcohol chain extender to completely convert the carboxyl group of the carboxylic acid type alcohol chain extender into a salt;

[0075] (6) controlling the temperature in the reactor at 50° C., adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion;

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

[0077] The final water-based silicone polyurethane resin includes silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units and amine chain extender structural units; the active hydrogen functional groups contained in silicone polyols, carboxylic acid type alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic acid type alcohol chain extenders react with the active end groups in the neutralizer to form anionic hydrophilic structural units.

[0078] Comparative Example 1

[0079] A method for preparing a water-based organosilicon polyurethane resin emulsion is basically the same as that of Example 1, except that PTMEG (Mitsubishi Chemical, number average molecular weight 1800) is used instead of double-terminal monohydroxy polyether modified polysiloxane.

[0080] Comparative Example 2

[0081] A method for preparing a water-based silicone polyurethane resin emulsion is basically the same as Example 1, except that PTMEG (Mitsubishi Chemical, number average molecular weight 3200) is used instead of single-terminal dihydroxy polysiloxane.

[0082] Example 2

[0083] A method for preparing an aqueous silicone polyurethane resin emulsion, the specific steps are as follows:

[0084] (1) Preparation of raw materials:

[0085] Silicone polyol: a combination of double-terminal monohydroxy polyether modified polysiloxane (Silok 8814, number average molecular weight 3600) and single-terminal dihydroxy polysiloxane (Silok 8826, number average molecular weight 4500), the mass ratio of double-terminal monohydroxy polyether modified polysiloxane to single-terminal dihydroxy polysiloxane is 2:1;

[0086] Diisocyanate; Isophorone diisocyanate;

[0087] Carboxylic acid 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: hexamethylenediamine;

[0092] Deionized water;

[0093] Among the raw material components, the raw materials participating in the reaction are as follows: the proportion of organosilicon polyol is 73.5wt%, the proportion of diisocyanate is 18wt%, the proportion of carboxylic acid type alcohol chain extender is 2.7wt%, the proportion of amine chain extender is 3wt%, and the molar ratio of neutralizer to carboxylic acid type alcohol chain extender is 1.05:1; 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 1.5;

[0094] (2) adding organosilicon polyol into a reaction kettle;

[0095] (3) adding diisocyanate into a reaction kettle and reacting at 102° C. for 2.5 hours until the organosilicon polyol is completely reacted;

[0096] (4) adding a carboxylic acid type alcohol chain extender into the reaction kettle, and reacting at 91° C. for 3 hours in the presence of a catalyst until the carboxylic acid type alcohol chain extender is completely reacted;

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

[0098] (6) controlling the temperature in the reactor at 49° C., adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion;

[0099] (7) Adding an amine chain extender into the reaction kettle, and after the reaction is completed, a water-based silicone polyurethane resin emulsion with a solid content of 40% is obtained.

[0100] The final water-based silicone polyurethane resin includes silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units and amine chain extender structural units; the active hydrogen functional groups contained in silicone polyols, carboxylic acid type alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic acid type alcohol chain extenders react with the active end groups in the neutralizer to form anionic hydrophilic structural units.

[0101] Example 3

[0102] A method for preparing an aqueous silicone polyurethane resin emulsion, the specific steps are as follows:

[0103] (1) Preparation of raw materials:

[0104] Silicone polyol: a combination of double-terminal monohydroxy polyether modified polysiloxane (Silok 8805, number average molecular weight 5500) and single-terminal dihydroxy polysiloxane (Silok 8821F31, number average molecular weight 3100), the mass ratio of double-terminal monohydroxy polyether modified polysiloxane to single-terminal dihydroxy polysiloxane is 1.5:1;

[0105] Diisocyanate; dicyclohexylmethane diisocyanate;

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

[0107] Catalyst: BICAT 8118;

[0108] Neutralizing agent: triethylamine;

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

[0110] Amine chain extender: isophorone diamine;

[0111] Deionized water;

[0112] Among the raw material components, the raw materials participating in the reaction are as follows: the proportion of organosilicon polyol is 70.6wt%, the proportion of diisocyanate is 19wt%, the proportion of carboxylic acid type alcohol chain extender is 4wt%, the proportion of amine chain extender is 2wt%, and the molar ratio of neutralizer to carboxylic acid type 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) adding organosilicon polyol into a reaction kettle;

[0114] (3) adding diisocyanate into a reaction kettle and reacting at 108° C. for 2.5 hours until the organosilicon polyol is completely reacted;

[0115] (4) adding a carboxylic acid type alcohol chain extender into the reaction kettle, and reacting at 93° C. for 2.5 hours in the presence of a catalyst until the carboxylic acid type alcohol chain extender is completely reacted;

[0116] (5) adding a neutralizing agent into the reaction kettle to react with the carboxylic acid type alcohol chain extender to completely convert the carboxyl group of the carboxylic acid type alcohol chain extender into a salt;

[0117] (6) controlling the temperature in the reactor at 48° C., adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion;

[0118] (7) Adding an amine chain extender into the reaction kettle, and after the reaction is completed, a water-based silicone polyurethane resin emulsion with a solid content of 35% is obtained.

[0119] The final water-based silicone polyurethane resin includes silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units and amine chain extender structural units; the active hydrogen functional groups contained in silicone polyols, carboxylic acid type alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic acid type alcohol chain extenders react with the active end groups in the neutralizer to form anionic hydrophilic structural units.

[0120] Example 4

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

[0122] (1) Preparation of raw materials:

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

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

[0125] Carboxylic acid 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] Among the raw material components, the raw materials participating in the reaction are as follows: the proportion of organosilicon polyol is 79wt%, the proportion of diisocyanate is 16wt%, the proportion of carboxylic acid type alcohol chain extender is 1.5wt%, the proportion of amine chain extender is 2wt%, and the molar ratio of neutralizer to carboxylic acid type 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) adding organosilicon polyol into a reaction kettle;

[0133] (3) adding diisocyanate into a reaction kettle and reacting at 110° C. for 2 hours until the organosilicon polyol is completely reacted;

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

[0135] (5) adding a neutralizing agent into the reaction kettle to react with the carboxylic acid type alcohol chain extender to completely convert the carboxyl group of the carboxylic acid type alcohol chain extender into a salt;

[0136] (6) controlling the temperature in the reactor at 45° C., adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion;

[0137] (7) Adding an amine chain extender into the reaction kettle, and after the reaction is completed, a water-based silicone polyurethane resin emulsion with a solid content of 50% is obtained.

[0138] The final water-based silicone polyurethane resin includes silicone polyol structural units, diisocyanate structural units, anionic hydrophilic structural units and amine chain extender structural units; the active hydrogen functional groups contained in silicone polyols, carboxylic acid type alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanate to form polyurethane chains; the carboxyl groups in the carboxylic acid type alcohol chain extenders react with the active end groups in the neutralizer to form anionic hydrophilic structural units.

[0139] Example 5

[0140] A method for preparing a highly soft water-based polyurethane microfiber base fabric, the specific steps are as follows:

[0141] (1) Preparing a first impregnation slurry: The aqueous silicone polyurethane resin emulsion of Example 1 is prepared to have a viscosity of 800 cps / 25° C. and a solid content of 5%;

[0142] (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, the liquid carrying rate is controlled to be 160%, and then coagulated in a 3 wt % oxalic acid aqueous solution for 10 min, and then washed and dried in sequence to obtain a blank;

[0143] (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening at 95°C and drying at 130°C to obtain a highly soft waterborne polyurethane microfiber base fabric; wherein the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 25% and a viscosity of 800cps / 25°C as the impregnation material, and the impregnation liquid rate is 160%. After impregnation, the blank is dried in an oven at 140°C to obtain an impregnated sea island fiber base fabric.

[0144] The final high-softness water-based polyurethane microfiber base fabric has a softness of 3.8 mm and a peel strength of 140 N / 2.54 cm.

[0145] Comparative Example 3

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

[0147] The final high-softness water-based polyurethane microfiber base fabric has a softness of 2.8 mm and a peel strength of 142 N / 2.54 cm.

[0148] By comparing Comparative Example 3 with Example 5, it can be found that the softness of Comparative Example 3 is significantly deteriorated. This is because the aqueous silicone polyurethane resin emulsion prepared in Comparative Example 1 introduces a polyether soft segment into the molecular structure, so the emulsion is not effective in protecting the fiber from adhesion, which leads to a significant decrease in softness.

[0149] Comparative Example 4

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

[0151] The final high-softness water-based polyurethane microfiber base fabric has a softness of 2.5 mm and a peel strength of 158 N / 2.54 cm.

[0152] By comparing Comparative Example 4 and Example 5, it can be found that the softness of Comparative Example 4 is significantly deteriorated. This is because the aqueous silicone polyurethane resin emulsion prepared in Comparative Example 2 introduces a polyether soft segment, so the emulsion is not effective in protecting fiber adhesion, which leads to a significant decrease in softness.

[0153] Comparative Example 5

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

[0155] The final high-softness water-based polyurethane microfiber base fabric has a softness of 3.6 mm and a peel strength of 82 N / 2.54 cm.

[0156] By comparing Comparative Example 5 with Example 5, it can be found that the peel strength of Comparative Example 5 is significantly deteriorated. This is because the molecular structure of the water-based silicone polyurethane resin prepared in Comparative Example 1 contains a large amount of silicone structure. Although such resin can effectively improve the softness by directly replacing conventional polyester or polyether polyurethane impregnation liquid, the silicone structure accounts for too large a proportion in the polyurethane molecular chain, resulting in performance loss and a significant decrease in peel strength.

[0157] Comparative Example 6

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

[0159] The final high-softness water-based polyurethane microfiber base fabric has a softness of 3.3 mm and a peel strength of 88 N / 2.54 cm.

[0160] By comparing Comparative Example 6 with Example 5, it can be found that the softness and peel strength of Comparative Example 5 are significantly deteriorated. This is because the molecular structure of the water-based silicone polyurethane resin prepared in Comparative Example 2 contains a large amount of silicone structure. Although such resin can be directly used to replace conventional polyester or polyether polyurethane impregnation liquid to effectively improve softness, the silicone structure accounts for too large a proportion in the polyurethane molecular chain, resulting in performance loss and a significant decrease in peel strength.

[0161] Example 6

[0162] A method for preparing a highly soft water-based polyurethane microfiber base fabric, the specific steps are as follows:

[0163] (1) Preparing the first impregnation slurry: the aqueous silicone polyurethane resin emulsion of Example 2 is prepared to have a viscosity of 900 cps / 25° C. and a solid content of 6%;

[0164] (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, the liquid carrying rate is controlled to be 170%, and then coagulated in a 3.5 wt % oxalic acid aqueous solution for 9 min, and then washed and dried in sequence to obtain a blank;

[0165] (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening at 96°C and drying at 125°C to obtain a highly soft waterborne polyurethane microfiber base fabric; wherein the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 25% and a viscosity of 900cps / 25°C as an impregnation material, and the impregnation liquid rate is 150%. After impregnation, the blank is dried in an oven at 135°C to obtain an impregnated sea island fiber base fabric.

[0166] The final high-softness water-based polyurethane microfiber base fabric has a softness of 3.9 mm and a peel strength of 136 N / 2.54 cm.

[0167] Example 7

[0168] A method for preparing a highly soft water-based polyurethane microfiber base fabric, the specific steps are as follows:

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

[0170] (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, the liquid carrying rate is controlled to be 180%, and then coagulated in a 4 wt % oxalic acid aqueous solution for 7 min, and then washed and dried in sequence to obtain a blank;

[0171] (3) The raw material obtained in step (2) is subjected to secondary impregnation, fiber opening at 98°C and drying at 125°C to obtain a highly soft waterborne polyurethane microfiber base fabric; wherein the secondary impregnation uses a conventional polyether type waterborne polyurethane resin emulsion with a solid content of 26% and a viscosity of 1100cps / 25°C as the impregnation material, and the impregnation liquid rate is 170%. After impregnation, the raw material is dried in an oven at 130°C to obtain an impregnated sea island fiber base fabric.

[0172] The final high-softness water-based polyurethane microfiber base fabric has a softness of 4 mm and a peel strength of 132 N / 2.54 cm.

[0173] Example 8

[0174] A method for preparing a highly soft water-based polyurethane microfiber base fabric, the specific steps are as follows:

[0175] (1) Preparing a first impregnation slurry: The aqueous silicone polyurethane resin emulsion of Example 4 is prepared to have a viscosity of 1200 cps / 25° C. and a solid content of 10%;

[0176] (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, the liquid carrying rate is controlled to be 200%, and then coagulated in a 5 wt % oxalic acid aqueous solution for 5 min, and then washed and dried in sequence to obtain a blank;

[0177] (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening at 100°C and drying at 120°C to obtain a highly soft 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 1200cps / 25°C as an impregnation material, and the impregnation liquid rate is 180%. After impregnation, it is dried in an oven at 120°C to obtain an impregnated sea island fiber base fabric.

[0178] The final high-softness water-based polyurethane microfiber base fabric has a softness of 4.2 mm and a peel strength of 128 N / 2.54 cm.

Claims

1. A water-based silicone polyurethane resin emulsion, characterized in that: The water-based 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 water-based silicone polyurethane resin include silicone polyols, amine chain extenders, carboxylic acid alcohol chain extenders, neutralizers and diisocyanates, but do not include polyester or polyether polyester oligomers; the active hydrogen functional groups contained in the silicone polyols, carboxylic acid alcohol chain extenders and amine chain extenders react with the NCO functional groups of diisocyanates to form polyurethane chains; the carboxyl groups in the carboxylic acid alcohol chain extenders react with the active end groups in the neutralizer to form anionic hydrophilic structural units; Among the raw material components involved in synthesizing the water-based silicone polyurethane resin, the proportion of silicone polyol is at least 70wt%, and the number average molecular weight of the silicone polyol is not less than 1750; The organosilicon polyol is a combination of double-terminal monohydroxyl polyether-modified polysiloxane and single-terminal dihydroxyl polysiloxane; the mass ratio of double-terminal monohydroxyl polyether-modified polysiloxane to single-terminal dihydroxyl polysiloxane is 1-2:

1.

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

3. The aqueous silicone polyurethane resin emulsion according to claim 1, characterized in that: In the raw material components involved in synthesizing the waterborne organosilicon polyurethane resin, the proportion of amine chain extenders is 2-3wt%, the proportion of carboxylic acid type alcohol chain extenders is 1.5-4wt%, and the molar ratio of neutralizer to carboxylic acid type alcohol chain extenders is 1-1.1:

1.

4. The aqueous silicone polyurethane resin emulsion according to claim 1, characterized in that: The amine chain extender is one or more of ethylenediamine, hexamethylenediamine, isophoronediamine, hydrazine hydrate, diethylenetriamine, propylenediamine and triethylenetetramine, the carboxylic acid type 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-hexamethylenediisocyanate, isophoronediisocyanate and dicyclohexylmethanediisocyanate.

5. A method for preparing an aqueous silicone polyurethane resin emulsion according to any one of claims 1 to 4, characterized in that The steps include: (1) putting organosilicon polyol into a reaction kettle; (2) adding diisocyanate into a reaction kettle, and controlling the reaction temperature at 100-110° C. until the organosilicon polyol is completely reacted; (3) adding a carboxylic acid type alcohol chain extender into the reaction kettle, and keeping the temperature at 90-95° C. for reaction until the carboxylic acid type alcohol chain extender is completely reacted; (4) adding a neutralizing agent into the reaction kettle to react with the carboxylic acid type alcohol chain extender to completely convert the carboxyl group of the carboxylic acid type alcohol chain extender into a salt; (5) controlling the temperature in the reactor to be below 50° C., first adding an emulsifier into the reactor and mixing it evenly, and then adding deionized water to form an emulsion; (6) Adding an amine chain extender into the reaction kettle, and obtaining the water-based silicone polyurethane resin emulsion after the reaction is complete.

6. A method for preparing a highly soft waterborne polyurethane microfiber fabric, characterized in that The steps include: (1) preparing a first impregnation slurry: preparing the aqueous silicone polyurethane resin emulsion according to any one of claims 1 to 4 to a viscosity of 800 to 1200 cps / 25° C. and a solid content of 5 to 10%; (2) One-time impregnation: The sea-island fiber nonwoven fabric is impregnated with the first impregnation slurry, and the liquid carrying rate is controlled to be 160-200%, and then solidified, washed and dried to obtain a blank; (3) The blank obtained in step (2) is subjected to secondary impregnation, fiber opening and drying to obtain a highly soft waterborne polyurethane microfiber base fabric; the secondary impregnation uses a polyether type waterborne polyurethane resin emulsion as an impregnating material.

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

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

9. The method for preparing a highly soft waterborne polyurethane microfiber-based fabric according to claim 6, characterized in that: The liquid carrying rate of step (3) is 150-180%. After impregnation, the impregnated sea island fiber base cloth is dried in an oven at 120-140°C to obtain the impregnated sea island fiber base cloth.