Temperature regulator for leather and method for its preparation

Abstract

The present application relates to the field of temperature adjusting agent for leather, to solve the problem of limited temperature adjusting effect of phase change material applied to leather in the prior art, provide a kind of temperature adjusting agent for leather and its preparation method, comprising: phase change microcapsule, end chloro glycerol tristearate and emulsifier;The phase change microcapsule includes: core material and shell material;The core material includes: polyethylene glycol and nanometer silicon dioxide;The shell material includes: nanometer titanium dioxide and sulfonated phenolic resin;The average molecular weight of polyethylene glycol is 1000-2000.The present application utilizes the permeability and viscosity of oil and fat, so that the phase change microcapsule can penetrate into the inside of leather, realize the distribution of phase change microcapsule in the inside of leather, and the temperature adjusting effect of leather is enhanced;Through the selection of specific oil and shell material, the oil, phase change microcapsule and collagen fiber have good bonding force, not only realize the stability of phase change microcapsule position, but also reduce the performance loss of leather after long-term use.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of temperature adjusting agent for leather, in particular to a temperature adjusting agent for leather and a preparation method thereof. BACKGROUND

[0002] Natural leather has unique excellent physical properties, and also has certain temperature adjusting function. However, in cold winter, the warmth retention of leather is far from enough, and the human body function cannot immediately adapt to the cold leather. In hot season, although the leather has good water vapor permeability, it still feels hot after contacting the leather. How to improve the temperature adaptability of leather has become a very important problem. The use of "thermal insulation" materials can actively respond to the change of external environment temperature, effectively regulate the heat exchange between human body and surrounding environment, and create a comfortable temperature environment for human body, which has important significance for functionalization of leather products, improvement of product added value, and energy saving.

[0003] At present, the materials with heat preservation function are mostly applied in textile materials, which improves the heat preservation performance of textile materials, and can keep the micro environment of textile products at a comfortable temperature, which provides an important reference for further improving the temperature adjusting function of leather. Among these heat preservation materials, phase change materials are an important type. The application of phase change materials to leather can improve the temperature adaptability of leather. In the prior art, phase change materials are mostly applied to the surface coating of leather, and the use amount and coverage are limited, and the temperature adjusting effect is limited, especially for the leather with high thickness, the temperature adjusting effect is poor. SUMMARY

[0004] The purpose of the present application is to provide a temperature adjusting agent for leather and a preparation method thereof, which solves the problem of limited temperature adjusting effect of phase change materials applied to leather in the prior art.

[0005] The embodiments of the present application are realized by the following technical solutions:

[0006] A temperature adjusting agent for leather comprises: phase change microcapsules, end-chlorine glycerol triesters and emulsifiers; the phase change microcapsules comprise: core materials and shell materials; the core materials comprise: polyethylene glycol and nano-silicon dioxide; the shell materials comprise: nano-titanium dioxide and sulfonated phenolic resin; the average molecular weight of the polyethylene glycol is 1000-2000.

[0007] The ecological leather is mostly woven by collagen fibers into a porous network structure, which has a large pore volume and specific surface area, so that it has good water vapor permeability and certain temperature regulation function. However, in order to make the leather more beautiful, the existing technology often performs finishing treatment on the surface of the leather, and the use of finishing materials will reduce the water vapor permeability of the leather to different degrees, and the temperature regulation function of the porous structure of the true skin layer cannot be exerted, and the smooth and dense coating significantly increases the heat conduction performance of the leather, and significantly reduces the warm feeling. In cold winter, the skin feels cold after contact and cannot be eliminated for a long time; and in hot summer, the skin will have sweating and sticky feeling after long-term contact, which seriously reduces the comfort of the ecological leather. Therefore, the applicant hopes to improve the temperature regulation function of the finished leather.

[0008] The present application utilizes the characteristics of the phase change material in the phase change microcapsule to make the leather have a self-temperature regulation function. When the environmental temperature is lower than the phase change point of the phase change material, the phase change material releases heat and becomes solid, thereby keeping the micro-environment temperature basically unchanged; when the environmental temperature is higher than the phase change point of the phase change material, the phase change material absorbs heat and becomes liquid, thereby keeping the micro-environment temperature basically unchanged. By adjusting the polymerization degree of polyethylene glycol, the phase change temperature of the material can tend to the use environment of the leather, such as close to the body temperature. However, the phase change temperature of polyethylene glycol basically increases with the increase of the molecular weight, and when applied to the use environment of the leather, the polymerization degree of polyethylene glycol is relatively low, and the low molecular weight polyethylene glycol has a high volume expansion rate after multiple phase changes due to the low crystallinity, and the shell material may be damaged. Therefore, the present application additionally dopes nano-silicon dioxide into polyethylene glycol to constrain the movement of polymer chain segments and reduce the thermal expansion coefficient of the material after multiple phase changes. The phase change enthalpy of polyethylene glycol increases with the increase of the molecular weight, but the present application selects low molecular weight polyethylene glycol, and after adding nano-silicon dioxide, the phase change enthalpy and phase change enthalpy retention rate of the phase change material can also be improved to a certain extent. In addition, the shell material needs to have certain structural strength and thermal conductivity, and high structural strength can effectively resist the expansion of the phase change material, and excellent thermal conductivity can better realize the heat transfer between the external environment and the shell internal environment. Although the metal shell material also has good thermal conductivity, the metal shell material is easy to oxidize, and therefore the present application selects nano-titanium dioxide with good thermal conductivity and can improve the anti-aging property of the system, and a sulfonated phenolic resin with good physical properties, corrosion resistance and antioxidant performance as the shell material.

[0009] The applicant thought of the principle of fatting agent when thinking about how to use phase change microcapsules in the internal structure of leather to improve the overall temperature regulation effect of leather. Thus, the technical scheme of compounding oil and phase change microcapsules was conceived, so that in the process of absorbing end-chlorine glycerol tristearate, phase change microcapsules penetrate into leather with end-chlorine glycerol tristearate, and as end-chlorine glycerol tristearate coats and gradually expands on the surface of collagen fibers, the mobility between fibers is enhanced, and the elasticity, toughness and extensibility of leather are improved. Phase change microcapsules are also dispersed on the surface of fibers, and the porous structure between fibers is the main air flow passage of leather, so heat is more easily in contact with phase change microcapsules, and the distribution area of phase change microcapsules is increased, thereby the temperature regulation effect of leather is better.

[0010] Under the above concept, the implementation of the scheme needs to consider at least the following points:

[0011] 1. The position stability of phase change microcapsules will affect the effect of leather after long-term use. For example, after the continuous deformation or washing of leather, phase change microcapsules may be separated from collagen fibers to produce aggregation or loss, thereby reducing the air permeability and weakening the temperature regulation effect. Phase change microcapsules may also migrate to the surface of leather to produce a "blooming" phenomenon, and the loss of phase change microcapsules will also weaken the temperature regulation effect.

[0012] 2. Whether phase change microcapsules will affect the penetration process of oil, such as penetration speed and penetration depth.

[0013] 3. Whether the lubricating effect of oil will affect the position stability of phase change microcapsules.

[0014] 4. Whether the bonding force between phase change microcapsules, oil and collagen fibers will affect the use effect, such as the bonding force between phase change microcapsules and collagen fibers being greater, which may affect the process of phase change microcapsules extending along the surface of collagen fibers with oil.

[0015] In order to solve the above problems, the applicant conceived to use sulfonated phenolic resin as the shell material, which can enhance the bonding degree between phase change microcapsules and collagen fibers by using the sulfonic acid group on the molecular structure.

[0016] Regarding the selection of oil types: the oil component in conventional fatting agents is mainly plant oil, but it contains a large number of unsaturated double bonds and is easy to oxidize. Therefore, the applicant uses end-chlorine glycerol tristearate, the specific structural formula and preparation method of which can refer to the patent with application number 202210963034.5 and the patent name "reaction type fatting agent and its preparation method".

[0017] One of the reasons for selecting the end-chlorine glycerol triester is that due to the addition of the phase change microcapsule, the present application needs to consider the binding force among the phase change microcapsule, the oil component and the collagen fiber. The sulfonated phenolic resin and the nano-titanium dioxide both contain hydroxyl groups, and the end-chlorine glycerol triester also has a large number of hydroxyl groups. Therefore, the end-chlorine glycerol triester not only has good binding degree with the collagen fiber due to the presence of chlorine, but also has good binding degree with the phase change microcapsule because a large number of hydroxyl groups can form hydrogen bonds between them. This is also one of the purposes of selecting the phenolic resin as the shell material. Under the cooperation of the end-chlorine glycerol triester, the sulfonated phenolic resin and the collagen fiber, the relative position stability of the three is high, which can not only reduce the decrease of air permeability caused by the aggregation of microcapsules, but also can limit the aggregation of oil through the phase change microcapsule, thereby reducing or avoiding the occurrence of the oil floating phenomenon. Finally, a large number of hydroxyl groups can also improve the emulsification effect of the system, reduce the particle size and distribution range of the emulsion droplets, and increase the stability of the system.

[0018] The nano-silicon dioxide can be mesoporous silicon dioxide, and the particle size of the silicon dioxide can be selected to be 50-100 nm, and the pore size can be selected to be 2-5 nm. The porous structure can further limit the movement of polyethylene glycol through adsorption, thereby reducing the swelling coefficient.

[0019] The emulsifier can be sodium dodecyl benzene sulfonate, fatty alcohol polyoxyethylene ether, ethoxylated fatty acid methyl ester and Tween series.

[0020] The particle size of the phase change microcapsule can be 0.3 μm-0.8 μm. When the leather is prepared by the vegetable tanning method, the gap between the collagen fibers is basically between 5 μm-50 μm. When the leather is prepared by the chrome tanning method, the gap between the collagen fibers of the leather is basically between 100 nm-500 nm. The present application can promote the penetration of the phase change microcapsule into the leather by reasonably controlling the size of the phase change microcapsule. In order to make the phase change microcapsule better play the effect, it can be preferentially applied to the leather prepared by the vegetable tanning method with high gap. Of course, when the chrome tanning method is used, the fiber gap of the leather product can be controlled to be above 300 nm by the existing technology, which not only facilitates the entry of the microcapsule into the collagen fibers, but also enables the leather to have good air permeability after the phase change microcapsule penetrates into the leather. Of course, the particle size of the phase change microcapsule will also affect its migration process.

[0021] Preferably, the polyethylene glycol includes 50wt%-60wt% of polyethylene glycol with an average molecular weight of 1000, 20wt%-30wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500.

[0022] Although the phase transition temperature of polyethylene glycol with average molecular weight of 1000 is closer to human body temperature, the applicant hopes to limit the thermal expansion of the rest of the polyethylene glycol by compounding different molecular weight polyethylene glycols, so that the polyethylene glycol that has not reached the phase transition temperature limits the thermal expansion of the rest of the polyethylene glycol. Of course, after the amount of polyethylene glycol with an average molecular weight of 1000 is reduced, if the external environmental temperature is only slightly higher than the phase transition temperature of PEG1000, only PEG1000 can effectively participate in temperature regulation at this time, and thus the amount of phase change microcapsules needs to be increased to a certain extent.

[0023] Preferably, the phase change microcapsules account for 6wt%-10wt% based on the weight of the end-chlorinated triglyceride, and the emulsifier accounts for 20wt%-30wt%.

[0024] The applicant also found in the test process that the addition of phase change microcapsules can affect the permeability of the temperature regulator. Among the influencing factors, the particle size and the proportion have a greater impact. When the proportion of phase change microcapsules is too high, the penetration speed and penetration depth of the temperature regulator will be reduced, and the air permeability of the leather will also be affected to a certain extent, and when the proportion of phase change microcapsules is too low, its improvement on the temperature regulation performance of the leather is limited, and thus the proportion of phase change microcapsules is reasonably limited.

[0025] A preparation method of a temperature regulator for leather, comprising the following steps:

[0026] S100, mixing phenol, formaldehyde, an acidic catalyst and nano titanium dioxide, and then reacting at 60-80℃ for 30-60min to obtain a prepolymer;

[0027] S200, mixing the prepolymer, an emulsifier and deionized water, and then adding phenol, formaldehyde, polyethylene glycol and nano silicon dioxide to obtain a mixed solution by ultrasonic dispersion;

[0028] S300, adding an aqueous solution of hexamethylenetetramine dropwise into the mixed solution, and then reacting at 100-120℃ for 20-40min, and then adding an aqueous solution of sodium pyrosulfite, and continuing to react for 40-60min, and finally filtering, washing and drying to obtain phase change microcapsules;

[0029] S400, mixing the phase change microcapsules, end-chlorinated triglyceride and emulsifier to obtain a temperature regulator for leather.

[0030] The purpose of using nano material to select silicon dioxide is also to prevent the silicon dioxide from migrating to the oil phase during the preparation of the microcapsules because the surface of the silicon dioxide contains a large number of silicon hydroxyl groups.

[0031] The acidic catalyst can be hydrochloric acid, oxalic acid and p-toluenesulfonic acid, etc.

[0032] The emulsifier can be the Span series, such as Span 80, Span 60 and Span 40, etc.

[0033] The reaction in S100 can be carried out under stirring or ultrasonic dispersion, and a dispersing agent can be added.

[0034] Preferably, in S100, the phenol is 3-5 parts, the formaldehyde is 7.5-12.5 parts, the acidic catalyst is 0.08-0.15 parts, and the nano-titanium dioxide is 0.5-2 parts by weight;

[0035] In S200, the phenol is 5-10 parts, the formaldehyde is 11.5-25 parts, the polyethylene glycol is 25-50 parts, the nano-silicon dioxide is 1-5 parts, the emulsifier is 0.1-0.25 parts, and the deionized water is 200-400 parts.

[0036] The ratio of shell material to core material affects the final effect of the product. Generally, the higher the proportion of core material, the better the temperature regulating effect. However, due to the limitation of particle size and the strength of the shell material, the actual amount of core material needs to be less than the maximum theoretical amount.

[0037] Preferably, in S300, the methenamine is 4-7 parts, and the sodium pyrosulfite is 12-18 parts; the concentration of methenamine aqueous solution is 25wt%-30wt%, and the concentration of sodium pyrosulfite aqueous solution is 40wt%-60wt%.

[0038] The degree of sulfonation of phenolic resin affects its bonding force with collagen fibers. The applicant found in experiments that when the degree of sulfonation of phenolic resin exceeds a certain value, the air permeability, temperature regulating effect and physical properties of leather will be affected to varying degrees. One of the reasons, according to the applicant's guess, is that when the bonding force between phenolic resin and collagen fibers is too high, it will affect the diffusion process of phase change microcapsules in the leather with oil. Therefore, the degree of sulfonation of phenolic acid resin is reasonably controlled.

[0039] Preferably, S300 includes: adding methenamine aqueous solution to the mixed solution, reacting at 100-120℃ for 20-40min, then adding dimethyl diallyl ammonium chloride aqueous solution and sodium hydroxide solution, reacting for 30min-60min, then adding sodium pyrosulfite aqueous solution, continuing to react for 40-60min, and finally filtering, washing and drying to obtain phase change microcapsules.

[0040] In order to further increase the position stability of the phase change microcapsules, the applicant further improves the shell material of the phase change microcapsules. After adding dimethyl diallyl ammonium chloride, the bonding force between phenolic resin and chloro-terminated triglyceride is stronger, which is beneficial to the leather to maintain good temperature regulating effect after multiple washing or deformation.

[0041] Preferably, in the S300, the dimethyl diallyl ammonium chloride is 12-16 parts by weight, and the sodium hydroxide solution is 20-40 parts by weight; the concentration of the dimethyl diallyl ammonium chloride aqueous solution is 20wt%-40wt%, and the concentration of the sodium hydroxide solution is 25wt%-40wt%.

[0042] Preferably, the ultrasonic frequency for ultrasonic dispersion is 30-40 kHz, the ultrasonic power is 300-400 W, and the ultrasonic time is 8-12 min.

[0043] The ultrasonic parameters can control the size of the droplets in the emulsion, and further control the particle size of the phase change microcapsule.

[0044] Preferably, the S100 comprises: nano-titanium dioxide after surface modification of the titanium dioxide by a silane coupling agent; phenol, formaldehyde and an acidic catalyst are mixed, and then reacted at 60-80 DEG C for 10-20 min, then nano-titanium dioxide is added, and then the reaction is continued at 100-120 DEG C for 20-40 min.

[0045] Although the addition of titanium dioxide in the process of phenolic resin synthesis is beneficial to the dispersion of titanium dioxide in the structure of phenolic resin, the compatibility of titanium dioxide is poor, and thus the surface of titanium dioxide is modified in the present application, so as to improve the dispersibility and compatibility of titanium dioxide.

[0046] The silane coupling agent can be KH570.

[0047] The present application has at least the following beneficial effects:

[0048] The present application uses the permeability and adhesion of oil and fat to make the phase change microcapsule penetrate into the inside of the leather, so as to realize the distribution of the phase change microcapsule in the leather, and the distribution area is wider and located in the main channel of heat transfer compared with the phase change microcapsule only on the surface of the leather, and thus the temperature regulating effect of the leather is enhanced; through the selection of specific oil and shell material, the combination between the oil, the phase change microcapsule and the collagen fiber is good, not only the stability of the position of the phase change microcapsule is realized, but also the migration and aggregation of the oil are limited by the phase change microcapsule, and the performance loss of the leather after long-term use is reduced; by adding silica in the core material, the thermal expansion coefficient and the phase change enthalpy loss of the polyethylene glycol after multiple phase changes are reduced; by adding titanium dioxide in the shell material, not only the thermal conductivity of the shell material is increased, but also the strength of the shell material is increased, and the aging resistance of the leather is improved. DETAILED DESCRIPTION

[0049] In order to make the purpose, method scheme and advantages of the embodiments of the present application more clear, the method scheme in the embodiments of the present application is described clearly and completely, obviously, the described embodiments are part of the embodiments of the present application, not all the embodiments.

[0050] Embodiment 1: A temperature regulator for leather, comprising: phase change microcapsules, end-chlorine glycerol triesters and emulsifiers; the phase change microcapsules comprise: core material and shell material; the core material comprises: polyethylene glycol and nano-silicon dioxide; the shell material comprises: nano-titanium dioxide and sulfonated phenolic resin; the average molecular weight of the polyethylene glycol is 2000. The phase change microcapsules account for 6wt% and the emulsifiers account for 20wt% based on the weight of the end-chlorine glycerol triesters.

[0051] Embodiment 2: A temperature regulator for leather, comprising: phase change microcapsules, end-chlorine glycerol triesters and emulsifiers; the phase change microcapsules comprise: core material and shell material; the core material comprises: polyethylene glycol and nano-silicon dioxide; the shell material comprises: nano-titanium dioxide and sulfonated phenolic resin; the average molecular weight of the polyethylene glycol is 1500. The phase change microcapsules account for 10wt% and the emulsifiers account for 30wt% based on the weight of the end-chlorine glycerol triesters.

[0052] Embodiment 3: A temperature regulator for leather, comprising: phase change microcapsules, end-chlorine glycerol triesters and emulsifiers; the phase change microcapsules comprise: core material and shell material; the core material comprises: polyethylene glycol and nano-silicon dioxide; the shell material comprises: nano-titanium dioxide and sulfonated phenolic resin; the average molecular weight of the polyethylene glycol is 1000. The phase change microcapsules account for 8wt% and the emulsifiers account for 25wt% based on the weight of the end-chlorine glycerol triesters.

[0053] Embodiment 4: A preparation method of a temperature regulator for leather, comprising the following steps in terms of weight parts:

[0054] S100, mixing phenol 3 parts, formaldehyde 7.5 parts, oxalic acid 0.08 parts and nano-titanium dioxide 0.5 parts, and then reacting at 60℃ for 30min to obtain a prepolymer;

[0055] S200, mixing the prepolymer, Span 40 0.1 parts and deionized water 200 parts, and then adding phenol 5 parts, formaldehyde 11.5 parts, polyethylene glycol 25 parts and nano-silicon dioxide 1 part to obtain a mixed solution by ultrasonic dispersion; the ultrasonic frequency for the ultrasonic dispersion is 30kHz, the ultrasonic power is 300W, and the ultrasonic time is 8min; the average molecular weight of the polyethylene glycol is 2000;

[0056] S300, dropping an aqueous solution of hexamethylenetetramine into the mixed solution, and then reacting at 100℃ for 20min, adding an aqueous solution of sodium pyrosulfite, and continuing to react for 40min, and finally obtaining phase change microcapsules by filtration, washing and drying; the hexamethylenetetramine is 4 parts, and the sodium pyrosulfite is 12 parts; the concentration of the aqueous solution of hexamethylenetetramine is 25wt%, and the concentration of the aqueous solution of sodium pyrosulfite is 40wt%;

[0057] S400, after mixing the phase change microcapsule, the end-chlorine glycerol triester and the emulsifier, a temperature adjusting agent for leather is obtained. The phase change microcapsule accounts for 6wt% and the emulsifier accounts for 20wt% based on the weight of the end-chlorine glycerol triester.

[0058] Example 5: A preparation method of a temperature adjusting agent for leather, including the following steps in terms of weight parts:

[0059] S100, after mixing phenol 5 parts, formaldehyde 12.5 parts, oxalic acid 0.15 parts and nano-titanium dioxide 2 parts, a prepolymer is obtained after reacting at 80℃ for 60min;

[0060] S200, after mixing the prepolymer, Span 40 0.25 parts and deionized water 400 parts, phenol 10 parts, formaldehyde 25 parts, polyethylene glycol 50 parts and nano-silicon dioxide 5 parts are added, and a mixed solution is obtained by ultrasonic dispersion; the ultrasonic frequency for the ultrasonic dispersion is 40kHz, the ultrasonic power is 400W, and the ultrasonic time is 12min; the average molecular weight of the polyethylene glycol is 1500;

[0061] S300, after adding an aqueous solution of hexamethylenetetramine to the mixed solution, an aqueous solution of sodium pyrosulfite is added after reacting at 120℃ for 40min, and the reaction is continued for 60min, and finally the phase change microcapsule is obtained after filtration, washing and drying; the hexamethylenetetramine is 7 parts, and the sodium pyrosulfite is 18 parts; the concentration of the aqueous solution of hexamethylenetetramine is 30wt%, and the concentration of the aqueous solution of sodium pyrosulfite is 60wt%;

[0062] S400, after mixing the phase change microcapsule, the end-chlorine glycerol triester and the emulsifier, a temperature adjusting agent for leather is obtained. The phase change microcapsule accounts for 6wt% and the emulsifier accounts for 20wt% based on the weight of the end-chlorine glycerol triester.

[0063] Example 6: A preparation method of a temperature adjusting agent for leather, including the following steps in terms of weight parts:

[0064] S100, after mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts and nano-titanium dioxide 1.2 parts, a prepolymer is obtained after reacting at 70℃ for 45min;

[0065] S200, after mixing the prepolymer, Span 40 0.17 parts and deionized water 300 parts, phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts and nano-silicon dioxide 3 parts are added, and a mixed solution is obtained by ultrasonic dispersion; the ultrasonic frequency for the ultrasonic dispersion is 35kHz, the ultrasonic power is 350W, and the ultrasonic time is 10min; the average molecular weight of the polyethylene glycol is 1000;

[0066] S300, the aqueous solution of hexamethylenetetramine is added dropwise into the mixed solution, after reaction at 110℃ for 30min, the aqueous solution of sodium metabisulfite is added, and the reaction is continued for 50min, finally, the phase change microcapsule is obtained after filtration, washing and drying; the hexamethylenetetramine is 5 parts, and the sodium metabisulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28wt%, and the concentration of the aqueous solution of sodium metabisulfite is 50wt%;

[0067] S400, the phase change microcapsule, the chloro-terminated triglyceride and the emulsifier are mixed to obtain the temperature adjusting agent for leather; the phase change microcapsule accounts for 8wt% based on the weight of the chloro-terminated triglyceride, and the emulsifier accounts for 25wt%.

[0068] Example 7: a preparation method of a temperature adjusting agent for leather, by weight, comprising the following steps:

[0069] S100, the phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts and nano titanium dioxide 1.2 parts are mixed, and after reaction at 70℃ for 45min, a prepolymer is obtained;

[0070] S200, the prepolymer, Span 40 0.17 parts and deionized water 300 parts are mixed, and then phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts and nano silicon dioxide 3 parts are added, and ultrasonic dispersion is performed to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35kHz, the ultrasonic power is 350W, and the ultrasonic time is 10min; the average molecular weight of the polyethylene glycol is 1000;

[0071] S300, the aqueous solution of hexamethylenetetramine is added dropwise into the mixed solution, after reaction at 110℃ for 30min, the aqueous solution of sodium metabisulfite is added, and the reaction is continued for 50min, finally, the phase change microcapsule is obtained after filtration, washing and drying; the hexamethylenetetramine is 5 parts, and the sodium metabisulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28wt%, and the concentration of the aqueous solution of sodium metabisulfite is 50wt%; the dimethyldiallylammonium chloride is 12 parts, and the sodium hydroxide solution is 20 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 20wt%, and the concentration of the sodium hydroxide solution is 25wt%;

[0072] S400, the phase change microcapsule, the chloro-terminated triglyceride and the emulsifier are mixed to obtain the temperature adjusting agent for leather; the phase change microcapsule accounts for 8wt% based on the weight of the chloro-terminated triglyceride, and the emulsifier accounts for 25wt%.

[0073] Example 8: a preparation method of a temperature adjusting agent for leather, by weight, comprising the following steps:

[0074] S100, mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts and nano titanium dioxide 1.2 parts, and then reacting at 70℃ for 45min to obtain a prepolymer;

[0075] S200, mixing the prepolymer, Span 40 0.17 parts and deionized water 300 parts, then adding phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts and nano silicon dioxide 3 parts, and ultrasonic dispersion to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35kHz, the ultrasonic power is 350W, and the ultrasonic time is 10min; the average molecular weight of the polyethylene glycol is 1000;

[0076] S300, adding an aqueous solution of hexamethylenetetramine to the mixed solution, and then reacting at 110℃ for 30min, adding an aqueous solution of dimethyldiallylammonium chloride and a sodium hydroxide solution, and then reacting for 60min, then adding an aqueous solution of sodium pyrosulfite, and continuing to react for 50min, and finally obtaining phase change microcapsules after filtration, washing and drying; the hexamethylenetetramine is 5 parts, the sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50wt%; the dimethyldiallylammonium chloride is 16 parts, and the sodium hydroxide solution is 40 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 40wt%, and the concentration of the sodium hydroxide solution is 40wt%;

[0077] S400, mixing the phase change microcapsules, the end-chlorinated triglyceride and the emulsifier to obtain a temperature adjusting agent for leather; the phase change microcapsules account for 8wt% and the emulsifier accounts for 25wt% based on the weight of the end-chlorinated triglyceride.

[0078] Example 9: a preparation method of a temperature adjusting agent for leather, including the following steps in parts by weight:

[0079] S100, mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts and nano titanium dioxide 1.2 parts, and then reacting at 70℃ for 45min to obtain a prepolymer;

[0080] S200, mixing the prepolymer, Span 40 0.17 parts and deionized water 300 parts, then adding phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts and nano silicon dioxide 3 parts, and ultrasonic dispersion to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35kHz, the ultrasonic power is 350W, and the ultrasonic time is 10min; the average molecular weight of the polyethylene glycol is 1000;

[0081] S300, the aqueous solution of methenamine is added dropwise into the mixed solution, after reacting at 110℃ for 30min, the aqueous solution of dimethyldiallylammonium chloride and sodium hydroxide solution are added, reacting for 45min, then the aqueous solution of sodium pyrosulfite is added, continuing to react for 50min, finally, the phase change microcapsule is obtained after filtration, washing and drying; the methenamine is 5 parts, the sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of methenamine is 28wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50wt%; the dimethyldiallylammonium chloride is 14 parts, the sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30wt%, the concentration of the sodium hydroxide solution is 28wt%;

[0082] S400, the phase change microcapsule, the end-chlorine triglyceride and the emulsifier are mixed to obtain the temperature adjusting agent for leather; the phase change microcapsule accounts for 8wt% and the emulsifier accounts for 25wt% based on the weight of the end-chlorine triglyceride.

[0083] Embodiment 10: a preparation method of a temperature adjusting agent for leather, including the following steps in parts by weight:

[0084] S100, the phenol 4 parts, the formaldehyde 10 parts, the oxalic acid 0.11 parts and the nano titanium dioxide 1.2 parts are mixed, then the pre-polymer is obtained after reacting at 70℃ for 45min;

[0085] S200, the pre-polymer, the Span 40 0.17 parts and the deionized water 300 parts are mixed, then the phenol 7 parts, the formaldehyde 18 parts, the polyethylene glycol 35 parts and the nano silicon dioxide 3 parts are added, and the mixed solution is obtained after ultrasonic dispersion; the ultrasonic frequency for the ultrasonic dispersion is 35kHz, the ultrasonic power is 350W, and the ultrasonic time is 10min; the polyethylene glycol includes: 50wt% of polyethylene glycol with an average molecular weight of 1000, 30wt% of polyethylene glycol with an average molecular weight of 2000, and the rest of polyethylene glycol with an average molecular weight of 1500;

[0086] S300, the aqueous solution of methenamine is added dropwise into the mixed solution, after reacting at 110℃ for 30min, the aqueous solution of dimethyldiallylammonium chloride and sodium hydroxide solution are added, reacting for 45min, then the aqueous solution of sodium pyrosulfite is added, continuing to react for 50min, finally, the phase change microcapsule is obtained after filtration, washing and drying; the methenamine is 5 parts, the sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of methenamine is 28wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50wt%; the dimethyldiallylammonium chloride is 14 parts, the sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30wt%, the concentration of the sodium hydroxide solution is 28wt%;

[0087] S400, the phase change microcapsule, the end-chlorine triglyceride and the emulsifier are mixed to obtain the temperature adjusting agent for leather. The phase change microcapsule accounts for 8wt% and the emulsifier accounts for 25wt% based on the weight of the end-chlorine triglyceride.

[0088] Embodiment 11: A preparation method of a temperature adjusting agent for leather, including the following steps in terms of weight parts:

[0089] S100, the phenol 4 parts, the formaldehyde 10 parts, the oxalic acid 0.11 parts and the nano-titanium dioxide 1.2 parts are mixed, and then a prepolymer is obtained after reaction at 70℃ for 45 min;

[0090] S200, the prepolymer, the Span 40 0.17 parts and the deionized water 300 parts are mixed, and then the phenol 7 parts, the formaldehyde 18 parts, the polyethylene glycol 35 parts and the nano-silicon dioxide 3 parts are added to obtain a mixed solution by ultrasonic dispersion; the ultrasonic frequency for the ultrasonic dispersion is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol includes: 60wt% of polyethylene glycol with an average molecular weight of 1000, 20wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500;

[0091] S300, the aqueous solution of hexamethylenetetramine is added dropwise into the mixed solution, and then a phase change microcapsule is obtained after reaction at 110℃ for 30 min, addition of the aqueous solution of dimethyldiallylammonium chloride and the sodium hydroxide solution, reaction for 45 min, addition of the aqueous solution of sodium pyrosulfite, and continuous reaction for 50 min, and finally filtration, washing and drying; the hexamethylenetetramine is 5 parts, and the sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28wt%, and the concentration of the aqueous solution of sodium pyrosulfite is 50wt%; the dimethyldiallylammonium chloride is 14 parts, and the sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30wt%, and the concentration of the sodium hydroxide solution is 28wt%;

[0092] S400, the phase change microcapsule, the end-chlorine triglyceride and the emulsifier are mixed to obtain the temperature adjusting agent for leather. The phase change microcapsule accounts for 8wt% and the emulsifier accounts for 25wt% based on the weight of the end-chlorine triglyceride.

[0093] Embodiment 12: A preparation method of a temperature adjusting agent for leather, including the following steps in terms of weight parts:

[0094] S100, the phenol 4 parts, the formaldehyde 10 parts, the oxalic acid 0.11 parts and the nano-titanium dioxide 1.2 parts are mixed, and then a prepolymer is obtained after reaction at 70℃ for 45 min;

[0095] S200, after mixing the prepolymer, Span 400 0.17 parts and deionized water 300 parts, add phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts, nano silicon dioxide 3 parts, ultrasonic dispersion to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol comprises: 55 wt% of polyethylene glycol with an average molecular weight of 1000, 26 wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500;

[0096] S300, drop the aqueous solution of hexamethylenetetramine into the mixed solution, react at 110℃ for 30min, then add the aqueous solution of dimethyldiallylammonium chloride and sodium hydroxide solution, react for 45min, then add the aqueous solution of sodium pyrosulfite, continue to react for 50min, and finally obtain the phase change microcapsule after filtration, washing and drying; hexamethylenetetramine is 5 parts, sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28 wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50 wt%; dimethyldiallylammonium chloride is 14 parts, sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30 wt%, the concentration of the sodium hydroxide solution is 28 wt%;

[0097] S400, after mixing the phase change microcapsule, end-chlorinated triglyceride and emulsifier, a temperature adjusting agent for leather is obtained. Based on the weight of the end-chlorinated triglyceride, the phase change microcapsule accounts for 8 wt%, and the emulsifier accounts for 25 wt%.

[0098] Example 13: A method for preparing a temperature adjusting agent for leather, comprising the following steps in parts by weight:

[0099] S100, after mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts, reacting at 60℃ for 10min, then adding nano titanium dioxide 1.2 parts, continuing to react at 100℃ for 20min, a prepolymer is obtained;

[0100] The nano titanium dioxide is titanium dioxide after surface modification by silane coupling agent, and the preparation method is as follows:

[0101] After dispersing the nano titanium dioxide in anhydrous ethanol, a dispersion liquid is obtained, and the amount of titanium dioxide is 0.1 g / ml; after mixing KH570 with anhydrous ethanol at a volume ratio of 1:15, adjusting the pH value to 10, then adding the aforementioned dispersion liquid, reacting at 60℃ for 1.2h, separating, washing and drying, the modified nano silicon dioxide is obtained. The mass ratio of KH570 to titanium dioxide is 0.5:1. (Controlling the degree of reaction can control the number of hydroxyl groups on the surface of titanium dioxide to a certain extent)

[0102] S200, after mixing the prepolymer, Span 400 0.17 parts and deionized water 300 parts, add phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts, nano silicon dioxide 3 parts, ultrasonic dispersion to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol comprises: 55 wt% of polyethylene glycol with an average molecular weight of 1000, 26 wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500;

[0103] S300, drop the aqueous solution of hexamethylenetetramine into the mixed solution, react at 110℃ for 30min, then add the aqueous solution of dimethyldiallylammonium chloride and sodium hydroxide solution, react for 45min, then add the aqueous solution of sodium pyrosulfite, continue to react for 50min, and finally obtain the phase change microcapsule after filtration, washing and drying; hexamethylenetetramine is 5 parts, sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28 wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50 wt%; dimethyldiallylammonium chloride is 14 parts, sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30 wt%, the concentration of the sodium hydroxide solution is 28 wt%;

[0104] S400, after mixing the phase change microcapsule, end-chlorinated triglyceride and emulsifier, a temperature adjusting agent for leather is obtained. Based on the weight of the end-chlorinated triglyceride, the phase change microcapsule accounts for 8 wt%, and the emulsifier accounts for 25 wt%.

[0105] Example 14: A method for preparing a temperature adjusting agent for leather, comprising the following steps in parts by weight:

[0106] S100, after mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts, reacting at 80℃ for 20min, then adding nano titanium dioxide 1.2 parts, continuing to react at 120℃ for 40min, a prepolymer is obtained;

[0107] The nano titanium dioxide is titanium dioxide after surface modification by silane coupling agent, and the preparation method is as follows:

[0108] After dispersing the nano titanium dioxide in anhydrous ethanol, a dispersion liquid is obtained, and the amount of titanium dioxide is 0.1 g / ml; after mixing KH570 with anhydrous ethanol at a volume ratio of 1:15, adjusting the pH value to 10, then adding the aforementioned dispersion liquid, reacting at 60℃ for 1.2h, separating, washing and drying, the modified nano silicon dioxide is obtained. The mass ratio of KH570 to titanium dioxide is 0.5:1. (Controlling the degree of reaction can control the number of hydroxyl groups on the surface of titanium dioxide to a certain extent)

[0109] S200, after mixing the prepolymer, Span 400 0.17 parts and deionized water 300 parts, add phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts, nano silicon dioxide 3 parts, ultrasonic dispersion to obtain a mixed solution; the ultrasonic frequency for ultrasonic dispersion is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol comprises: 55 wt% of polyethylene glycol with an average molecular weight of 1000, 26 wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500;

[0110] S300, drop the aqueous solution of hexamethylenetetramine into the mixed solution, react at 110℃ for 30min, then add the aqueous solution of dimethyl diallyl ammonium chloride and sodium hydroxide solution, react for 45min, then add the aqueous solution of sodium pyrosulfite, continue to react for 50min, finally filter, wash and dry to obtain phase change microcapsules; hexamethylenetetramine is 5 parts, sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50wt%; dimethyl diallyl ammonium chloride is 14 parts, sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyl diallyl ammonium chloride is 30wt%, the concentration of the sodium hydroxide solution is 28wt%;

[0111] S400, after mixing the phase change microcapsules, end-chlorinated triglyceride and emulsifier, a temperature adjusting agent for leather is obtained. Based on the weight of the end-chlorinated triglyceride, the phase change microcapsules account for 8wt%, and the emulsifier accounts for 25wt%.

[0112] Example 15: A method for preparing a temperature adjusting agent for leather, comprising the following steps in parts by weight:

[0113] S100, after mixing phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts, reacting at 68℃ for 14min, then adding nano titanium dioxide 1.2 parts, continuing to react at 110℃ for 30min, a prepolymer is obtained;

[0114] The nano titanium dioxide is titanium dioxide after surface modification by silane coupling agent, and the preparation method is as follows:

[0115] After dispersing the nano titanium dioxide in anhydrous ethanol, a dispersion liquid is obtained, and the amount of titanium dioxide is 0.1g / ml; after mixing KH570 and anhydrous ethanol at a volume ratio of 1:15, adjusting the pH value to 10, then adding the aforementioned dispersion liquid, reacting at 60℃ for 1.2h, separating, washing and drying to obtain modified nano silicon dioxide. The mass ratio of KH570 to titanium dioxide is 0.5:1. (Controlling the degree of reaction can control the number of hydroxyl groups on the surface of titanium dioxide to a certain extent)

[0116] S200, after mixing the prepolymer, Span 400 0.17 parts and deionized water 300 parts, phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts, nano silicon dioxide 3 parts are added, and a mixed solution is obtained by ultrasonic dispersion; the ultrasonic frequency for ultrasonic dispersion is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol comprises: 55 wt% of polyethylene glycol with an average molecular weight of 1000, 26 wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500;

[0117] S300, the aqueous solution of hexamethylenetetramine is added dropwise into the mixed solution, after reaction at 110℃ for 30 min, the aqueous solution of dimethyldiallylammonium chloride and sodium hydroxide solution are added, and reacted for 45 min, then the aqueous solution of sodium pyrosulfite is added, and the reaction is continued for 50 min, finally, after filtration, washing and drying, the phase change microcapsule is obtained; hexamethylenetetramine is 5 parts, sodium pyrosulfite is 15 parts; the concentration of the aqueous solution of hexamethylenetetramine is 28 wt%, the concentration of the aqueous solution of sodium pyrosulfite is 50 wt%; dimethyldiallylammonium chloride is 14 parts, sodium hydroxide solution is 30 parts; the concentration of the aqueous solution of dimethyldiallylammonium chloride is 30 wt%, the concentration of the sodium hydroxide solution is 28 wt%;

[0118] S400, after mixing the phase change microcapsule, the end-chlorine glycerol triester and the emulsifier, a temperature adjusting agent for leather is obtained. Based on the weight of the end-chlorine glycerol triester, the phase change microcapsule accounts for 8 wt%, and the emulsifier accounts for 25 wt%.

[0119] Comparative Example 1: The difference from Example 15 is that no titanium dioxide is added.

[0120] Comparative Example 2: The difference from Example 15 is that no nano silicon dioxide is added.

[0121] Comparative Example 3: The difference from Example 15 is that the phase change microcapsule accounts for 20 wt% based on the weight of the end-chlorine glycerol triester.

[0122] Comparative Example 4: The difference from Example 15 is that the ultrasonic frequency is 20 kHz.

[0123] Comparative Example 5: The difference from Example 15 is that 25 parts of sodium pyrosulfite are added in S300.

[0124] Blank Example: Referring to the preparation method of Example 1 in the patent with application number 202210963034.5, the specific process is as follows:

[0125] Mix 112.5 g lactic acid with 2.25 g tetrabutylammonium bromide, 4.5 g triphenylphosphine, add into a three-necked flask, stir at room temperature for 10 min, then add 300 g epoxidized soybean oil, heat to 80 °C and stir for 8 h to obtain an epoxidized soybean oil ring-opening product. Mix the above product with 7 g triphenylphosphine in a three-necked flask at room temperature, then add 210 g epichlorohydrin, heat to 70 °C and stir for 10 h to obtain a terminal chloro glyceride.

[0126] Take out the product and mix with 56 g Tween 80 at 70 °C for 2 h to obtain a fatliquoring agent.

[0127] The preparation method of the terminal chloro glyceride used in Examples 4-15 and Comparative Examples 1-5 is the same as that of the blank example.

[0128] Test 1: The temperature regulating agent prepared according to the preparation method provided in Examples 4-15 and Comparative Examples 1-5 is used for temperature regulation of vegetable tanning leather according to the mode of Application Example 1 in the patent with application number 202210963034.5, as follows:

[0129] Put the uniformed blue leather of cowhide sofa leather into a rotating drum, and sequentially perform softening, washing, and re-tanning according to the conventional process, then add 8% of the temperature regulating agent, 100% of water, based on the weight of the uniformed blue leather, and rotate at a temperature of 50 °C for 1 h, then add formic acid 0.5% four times and rotate for 15 min each time.

[0130] Test the tensile strength of the leather (N / mm 2 ) according to QB / T 1269-2012, test the softness of the leather (mm) according to GB / T 39371-2020, and test the oil absorption rate, and the test results are shown in Table 1.

[0131] Table 1

[0132]

[0133] From the test results of Example 4-15, it can be seen that the leather has good physical properties after using the temperature regulating agent provided by the present application, and the absorption rate of the temperature regulating agent is good.

[0134] From the comparison of Examples 4-6 and the blank example, it can be seen that after adding the phase change microcapsule, the absorption rate of the temperature regulating agent is affected to a certain extent, and the softness is also reduced to a certain extent, but the tensile strength is increased to a certain extent. The applicant speculates that the reason is that the addition of the phase change microcapsule compensates for the decrease in tensile strength caused by the decrease in oil absorption rate.

[0135] From the comparison of Example 7 and Example 6, it can be seen that the addition of dimethyl diallyl ammonium chloride improves the oil absorption rate and the physical properties of the leather to some extent. The applicant speculates that the reason is that after the shell material reacts with dimethyl diallyl ammonium chloride, the phase change microcapsules are more easily diffused with the oil, which to some extent reduces the influence of the phase change microcapsules on the diffusion of the oil.

[0136] From the comparison of Example 10 and Example 9, it can be seen that although the change in the molecular weight of polyethylene glycol slightly reduces the physical properties of the leather, the degree of influence is very small. The applicant speculates that the reason is that the change in the weight percentage of the core material may to some extent affect the diffusion process of the core material with the oil.

[0137] From the comparison of Example 13 and Example 12, it can be seen that the physical properties of the leather are improved to some extent after S100 adopts a segmented reaction and modified nano titanium dioxide. The applicant speculates that the reason is that the uniformity and bonding force of titanium dioxide in the phenolic resin are increased, which to some extent increases the physical properties of the shell material, and further increases the physical properties of the fibers. The modification of titanium dioxide also to some extent increases the compatibility of the surface of the phase change microcapsules with the oil, reducing the influence of the phase change microcapsules on the diffusion of the oil.

[0138] From the test results of Comparative Example 1 and Example 15, it can be seen that the addition of titanium dioxide can improve the physical properties of the leather. The applicant believes that the reason is that the titanium dioxide improves the physical properties of the shell material and the bonding force of the phase change microcapsules with the oil.

[0139] From the test results of Comparative Example 2 and Example 15, it can be seen that the addition of silicon dioxide has little effect on the physical properties of the leather.

[0140] From the test results of Comparative Example 3 and Example 15, it can be seen that when the percentage of phase change microcapsules increases, the physical properties of the leather will decrease. The applicant speculates that the reason is that the phase change microcapsules affect the diffusivity of the oil, but the decrease in tensile strength is not high, and the absorption rate is reduced, but the increase in the amount of phase change microcapsules to some extent compensates for the decrease in tensile strength.

[0141] From the test results of Comparative Example 4 and Example 15, it can be seen that too low ultrasonic frequency will affect the physical properties of the leather. The applicant speculates that the reason is that the increase in the particle size of the phase change microcapsules affects the infiltration process of itself and the oil.

[0142] From the test results of Comparative Example 5 and Example 15, it can be seen that excessive sulfonation of phenolic resin will affect the physical properties of the leather. The applicant speculates that the reason is that the bonding force between the phase change microcapsules and the collagen fibers is too high, which affects the migration of the oil.

[0143] Test two: performance test of the tannage added with the temperature adjusting agent in test one, including the heat enthalpy (J / g), the heat enthalpy loss rate after 100 phase changes (the first loss rate) and the heat enthalpy loss rate after 30 washes (the second loss rate).

[0144] The heat enthalpy test method is as follows:

[0145] Using a differential scanning calorimeter, preheat to room temperature, and pass nitrogen as a protective gas. Take the leather sample, and heat to 50℃ at a heating rate of 3℃ / min, and after holding for 2 min, cool to 0℃.

[0146] The heat enthalpy loss rate test method after 100 phase changes is as follows:

[0147] According to the heat enthalpy test method, reciprocatingly heat and cool 100 times, each time interval is 5 min, then test the phase change heat enthalpy, and calculate the heat enthalpy loss rate.

[0148] The heat enthalpy loss rate test method after 30 washes is as follows:

[0149] According to the washing method in the standard test method for color fastness and color transfer in leather washing in ASTM D2096-11 (2024), wash the leather for 30 times, then test the phase change heat enthalpy, and calculate the heat enthalpy loss rate.

[0150] The test results are shown in Table two.

[0151] Table two

[0152]

[0153] From the test results of examples 4-15, it can be seen that the leather has good temperature adjusting effect after using the temperature adjusting agent provided by the application, and the temperature adjusting effect retention rate after long-term use is high.

[0154] From the comparison of example 7 and example 6, it can be seen that after adding dimethyl diallyl ammonium chloride, the initial temperature adjusting effect of the leather and the first heat loss change little, but the temperature adjusting effect retention rate of the leather after long-term use is improved. The applicant guesses that the reason is that the further improvement of the shell material improves the position stability of the phase change microcapsule, and then the temperature adjusting effect after multiple washes is improved.

[0155] From the comparison of example 10 and example 9, it can be seen that the distribution of polyethylene glycol molecular weight affects the temperature adjusting effect of the leather. The applicant guesses that the reason is that after the expansion of polyethylene glycol is limited, the damage of the shell material is reduced.

[0156] From the comparison of example 13 and example 12, it can be seen that the heat enthalpy value and temperature adjustment effect retention rate of the leather are improved to a certain extent after the segmented reaction and the modified nano titanium dioxide are used. The applicant guesses that the reason is that the increase of the shell material strength and the compatibility of the phase change microcapsule and the oil improves the temperature adjustment effect retention rate of the leather, and the increase of the thermal conductivity of the shell material improves the heat enthalpy value to a certain extent.

[0157] From the results of examples 10-12 in table one and table two, it can be seen that although the physical properties decrease to a certain extent after the molecular weight distribution of polyethylene glycol is changed, the temperature adjustment performance and the temperature adjustment performance after long-term use are obviously improved.

[0158] From the comparison of comparative example 1 and example 15, it can be seen that the addition of titanium dioxide improves the temperature adjustment performance and the temperature adjustment effect retention rate of the leather. The applicant guesses that the reason is that the titanium dioxide improves the thermal conductivity and structural strength of the shell material.

[0159] From the test results of comparative example 2 and example 15, it can be seen that the addition of silicon dioxide reduces the phase change latent heat to a certain extent, but greatly reduces the first loss rate. The applicant guesses that the reason is that the addition of silicon dioxide reduces the thermal expansion coefficient of polyethylene glycol to a certain extent, especially the thermal expansion coefficient after multiple phase changes.

[0160] From the test results of comparative example 3 and example 15, it can be seen that when the proportion of phase change microcapsules increases, the temperature adjustment performance of the leather will decrease slightly. The applicant guesses that the reason is that the phase change microcapsules affect the diffusivity of the oil, and then affect the absorption rate of the phase change microcapsules as a whole, and too much phase change microcapsules will affect the air permeability of the leather, and then affect the heat exchange process of the phase change microcapsules.

[0161] From the test results of comparative example 4 and example 15, it can be seen that the ultrasonic frequency is too low to affect the temperature adjustment performance and the temperature adjustment performance retention rate of the leather. The applicant guesses that the reason is that the increase of the particle size of the phase change microcapsules affects the infiltration process of the phase change microcapsules and the oil, and the position stability of the phase change microcapsules is also affected to a certain extent after the particle size increases.

[0162] From the test results of comparative example 5 and example 15, it can be seen that excessive sulfonation of phenolic resin has little effect on the temperature adjustment performance of the leather, but from the results of table one, it can be seen that it greatly affects the physical properties of the leather.

[0163] The above is only the preferred embodiment of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for preparing a temperature adjusting agent for leather, characterized by, The following steps are included by weight parts: S100, phenol 4 parts, formaldehyde 10 parts, oxalic acid 0.11 parts are mixed and reacted at 68°C for 14 min, then 1.2 parts of nano titanium dioxide is added, and the reaction is continued at 110°C for 30 min to obtain a prepolymer; The modified nano titanium dioxide is prepared by the following method: The nano titanium dioxide is dispersed in anhydrous ethanol to obtain a dispersion liquid, and the amount of titanium dioxide is 0.1 g / ml; KH570 and anhydrous ethanol are mixed in a volume ratio of 1:15, the pH value is adjusted to 10, then the above dispersion liquid is added, and the reaction is carried out at 60°C for 1.2h, after separation, washing and drying, the modified nano silicon dioxide is obtained, and the mass ratio of KH570 to titanium dioxide is 0.5:1; S200, the prepolymer, Span 40 0.17 parts and deionized water 300 parts are mixed, then phenol 7 parts, formaldehyde 18 parts, polyethylene glycol 35 parts and nano silicon dioxide 3 parts are added, and an ultrasonic dispersion is obtained; the ultrasonic frequency is 35 kHz, the ultrasonic power is 350 W, and the ultrasonic time is 10 min; the polyethylene glycol includes: 55wt% of polyethylene glycol with an average molecular weight of 1000, 26wt% of polyethylene glycol with an average molecular weight of 2000, and the balance of polyethylene glycol with an average molecular weight of 1500; S300, 5 parts of a 28wt% aqueous solution of hexamethyl tetramine are added to the mixed solution, and the reaction is carried out at 110°C for 30 min, then 14 parts of a 30wt% aqueous solution of dimethyl diallyl ammonium chloride and 30 parts of a 28wt% sodium hydroxide solution are added, and the reaction is carried out for 45 min, then 15 parts of a 50wt% aqueous solution of sodium pyrosulfite is added, and the reaction is continued for 50 min, and finally the phase change microcapsule is obtained after filtration, washing and drying; S400, the phase change microcapsule, the chloro-terminated triglyceride and the Tween are mixed to obtain a temperature adjusting agent for leather; based on the weight of the chloro-terminated triglyceride, the phase change microcapsule accounts for 8wt%, and the Tween accounts for 25wt%; The preparation method of the chloro-terminated triglyceride includes: mixing 112.5g of lactic acid with 2.25g of tetrabutylammonium bromide and 4.5g of triphenylphosphine, adding into a three-necked flask and stirring at room temperature for 10 min, then adding 300g of epoxy soybean oil, heating to 80°C and stirring for 8h to obtain an epoxy soybean oil ring-opening product, mixing the above product with 7g of triphenylphosphine in a three-necked flask at room temperature, then adding 210g of epoxy chloropropane, heating to 70°C and stirring for 10h to obtain the chloro-terminated triglyceride.

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