Rosin-free hot wax for hair removal and preparation method thereof

Abstract

The invention relates to a rosin-free depilatory hot wax and a preparation method thereof, and belongs to the technical field of depilatory hot wax. The depilatory hot wax comprises the following raw materials by weight: 30 to 70 parts of wax-based substances, 1 to 5 parts of carboxylated cellulose nanocrystals, 3 to 7 parts of coconut oil-based wax esters, 0.1 to 1 parts of depilatory proteases, 5 to 10 parts of modified polyols, 3 to 5 parts of polyurethane dispersions and 0.3 to 2 parts of colorants; wherein the coconut oil-based wax esters are synthesized from coconut oil, coconut alcohol and immobilized lipase; the modified polyols are synthesized from triglycerides after epoxidation reaction and then hydroxylation reaction. The depilatory hot wax of the invention does not add any additives containing any rosin or rosin derivatives with rosin as raw material, thus avoiding the occurrence of users being allergic to rosin and its derivatives, and has high depilatory efficiency, low drop melting point, can significantly reduce skin pain, and has good film-forming properties and is easy to tear.

Description

Technical Field

[0001] The invention relates to the technical field of depilatory hot wax, and in particular to rosin-free depilatory hot wax and a preparation method thereof. Background Art

[0002] Hot wax is a cosmetic product used to remove excess hair from the skin surface by physically pulling the hair out of the follicles. Hot wax needs to be heated to a molten state before use so that it can be applied to the skin. Hot wax Hot wax applied to the skin forms a thin film that hardens after cooling, allowing it to grab the hair, so the hot wax adheres firmly to the hair after cooling. Hot wax can pull the hair out by the roots, so the hair removal effect is more thorough, and the growth of new hair is relatively slow.

[0003] The basic ingredients of hot wax include beeswax, resin, fatty alcohol, tackifier, plasticizer, antioxidant, etc. The most common ones are to increase the viscosity of hot wax by containing rosin or its derivatives. Although the depilatory hot wax containing rosin has a good depilatory effect, it also has some disadvantages: about 7% of the population may be allergic to rosin, which may cause skin redness, itching and other allergic reactions when using depilatory hot wax containing rosin. After using depilatory hot wax containing rosin, special lotions and sprays may be needed for cleaning and disinfection, as well as to prevent skin allergies, which increases the complexity of the use process. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a rosin-free hair removal hot wax and a preparation method thereof, which does not add rosin and other allergenic ingredients and has good adhesion.

[0005] To achieve the above object, the technical solution adopted by the present invention is:

[0006] In a first aspect, the present invention provides a rosin-free depilatory hot wax, comprising the following raw materials in parts by weight: 30 to 70 parts of a wax-based substance, 1 to 5 parts of carboxylated cellulose nanocrystals, 3 to 7 parts of coconut oil-based wax esters, 0.1 to 1 parts of depilatory protease, 5 to 10 parts of modified polyols, 3 to 5 parts of polyurethane dispersions and 0.3 to 2 parts of colorants; wherein the coconut oil-based wax esters are synthesized from coconut oil, coconut alcohol and immobilized lipase; and the modified polyols are synthesized from triglycerides through an epoxidation reaction and then a hydroxylation reaction.

[0007] The carboxylated cellulose nanocrystals (cCNCs) of the rosin-free hair removal hot wax of the present invention have a high specific surface area and surface chemical activity, and can increase the adhesion of the hair removal wax to the hair, thereby improving the hair removal effect. The carboxyl functional groups on the surface of the cCNCs react with the modified polyol and the coconut oil-based wax ester to form hydrogen bonds, enhance the interface interaction, and promote their uniform dispersion and network formation in the matrix, so that the adhesion, mechanical properties and toughness of the hair removal wax can be improved, which helps to more effectively adhere to and remove hair, and also helps the wax to maintain integrity and reduce breakage when removing hair.

[0008] Coconut oil-based wax esters help promote the formation of a uniform and stable wax film on the wax-based substance, which can firmly adhere to the skin and hair, thereby improving the efficiency of hair removal. The lubricating effect of coconut oil-based wax esters helps reduce discomfort during hair removal, and can also improve the ductility of hair removal wax, making it easier to evenly cover the skin and reduce friction and irritation to the skin. In addition, coconut oil-based wax esters also have a certain emulsification ability, which helps to form tiny wax oil emulsions, making the wax easier to remove during the washing process and reducing residue on the skin. Because it has a unique smell, it can add a natural fragrance to the hair removal wax, so the hair removal wax can reduce or no fragrance. In addition, coconut oil-based wax esters are ingredients of natural origin, have good biodegradability, and are environmentally friendly.

[0009] Modified polyols are obtained by introducing epoxy groups into triglycerides through epoxidation reaction, and then further reacting with hydroxylation reagents. The hydroxylation reaction increases the polar groups in the molecule and improves the interaction with hair. The addition of modified polyols can change the rheological properties of depilatory wax, making it more suitable for depilatory operations.

[0010] Polyurethane dispersants can improve the uniform film-forming ability of depilatory wax on the skin surface, forming a continuous, uniform and elastic film, which helps to adhere to hair more effectively. When removing, the wax can be torn off in one piece, making it possible to remove hair more thoroughly. In addition, polyurethane dispersants can increase the flexibility of depilatory wax, reduce breakage during application and removal, and improve the user experience.

[0011] Preferably, the method for preparing the modified polyol comprises the following steps:

[0012] (1) mixing formic acid and hydrogen peroxide to obtain a reaction mixture;

[0013] (2) cooling the reaction mixture, mixing the reaction mixture and triglyceride, and then reacting, then taking out the reactant for filtering, taking out the precipitate for washing, and drying to obtain epoxidized triglyceride;

[0014] (3) mixing the epoxidized triglyceride with the acid solution to carry out a hydroxylation synthesis reaction, filtering after the reaction is completed, taking out the precipitate, washing it, and drying it to obtain the modified polyol.

[0015] Preferably, the mass ratio of triglyceride to formic acid and hydrogen peroxide is 1:(0.9-1.2):(1.2-1.5).

[0016] Preferably, the mixing temperature in step (1) is 45 to 55° C. and the mixing time is 10 to 20 minutes.

[0017] Preferably, in step (2), the reaction mixture is cooled to 0-10°C.

[0018] Preferably, in step (2), the reaction temperature is 45-55° C. and the reaction time is 1-2 h.

[0019] Preferably, the mass ratio of epoxidized triglyceride to acid solution is (9-11):1.

[0020] Preferably, the reaction temperature of the hydroxylation synthesis reaction is 45-55° C. and the reaction time is 18-20 h.

[0021] Preferably, the preparation method of the coconut oil-based wax ester comprises the following steps: coconut oil is mixed with coconut oil alcohol, and immobilized lipase is added to carry out alcoholysis reaction to obtain coconut oil-based wax ester. Lipase is an enzyme that can catalyze the hydrolysis and synthesis of ester bonds. In the alcoholysis reaction, immobilized lipase can catalyze the transesterification reaction between triglycerides in coconut oil and coconut oil alcohol. Under the catalysis of lipase, the ester bonds in coconut oil are opened, and the fatty acid chains in the triglyceride molecules are transferred to the hydroxyl groups of coconut oil alcohol to form new ester compounds, namely coconut oil-based wax ester.

[0022] Preferably, the molar ratio of coconut oil to coconut alcohol is 1:(2-4).

[0023] Preferably, the alcoholysis reaction is carried out at a temperature of 30 to 45° C. and for a time of 18 to 24 hours.

[0024] Preferably, the added amount of the coconut oil and the immobilized lipase is (100-110) mg: (5-10) U.

[0025] Preferably, the wax-based substance is at least one of paraffin wax, microcrystalline wax, beeswax, wood wax, polyethylene wax, polypropylene wax, palm wax, carabar wax and castor wax.

[0026] Preferably, the wax-based substance is a composition of beeswax and microcrystalline wax in a mass ratio of (3-5):1. More preferably, it is a composition of beeswax and microcrystalline wax in a mass ratio of 4:1. Paraffin wax and microcrystalline wax can provide a gentler hair removal experience while maintaining a highly effective hair removal effect. Due to the chemical inertness of paraffin wax and microcrystalline wax, they have a better affinity for the skin, reducing possible irritation or allergic reactions.

[0027] Preferably, the depilatory protease is keratinase, saccharifying enzyme and cellulase in a mass ratio of 1:1:1. Saccharifying enzyme can clean the pores, and keratinase and cellulase can soften the hair on the skin surface, thereby making the depilatory efficiency higher.

[0028] In a second aspect, the present invention provides a method for preparing the rosin-free hot wax for hair removal, comprising the following steps:

[0029] S1, heating the wax-based substance, modified polyol, coconut oil-based wax ester and polyurethane dispersion until they are melted, and stirring them evenly to obtain a first mixture;

[0030] S2, adding carboxylated cellulose nanocrystals, depilatory protease and colorant to the first mixture, heating and mixing, cooling and forming, to obtain the rosin-free depilatory hot wax.

[0031] It should be noted that the epoxidized polyol and the polyurethane dispersion may be subjected to a ring-opening reaction by adding a catalyst to form a polyurethane-polyol network structure, or may be subjected to a ring-opening reaction without adding a catalyst. Preferably, the catalyst is an amine nucleophile and / or an organotin compound.

[0032] Preferably, in step S1, the heating temperature is 180-200°C.

[0033] Preferably, in step S2, the heating temperature is 90-100°C.

[0034] Compared with the prior art, the present invention has the following beneficial effects:

[0035] (1) The main components of the depilatory hot wax of the present invention are wax-based substances, carboxylated cellulose nanocrystals (cCNCs), coconut oil-based wax esters, depilatory protease, epoxidized polyols and polyurethane dispersions, and no additives containing any rosin or rosin derivatives with rosin as raw materials are added, thereby avoiding the occurrence of users being allergic to rosin and its derivatives. In addition, the depilatory hot wax has high depilatory efficiency, low drop melting point, can significantly reduce skin pain, and has good film-forming properties and is easy to tear.

[0036] (2) The addition of cCNCs can improve the mechanical strength and toughness of depilatory wax, making the wax film more resistant to cracking and easier to handle. cCNCs and polyurethane dispersions can act as dispersants to improve the dispersibility of other ingredients in the wax matrix and ensure the uniformity and consistency of the depilatory wax. Epoxidized polyols and polyurethane dispersions can improve the thermal stability of depilatory wax and ensure the stable performance of the wax during heating and cooling.

[0037] (3) Coconut oil-based wax esters and epoxidized polyols can increase the adhesion of depilatory wax and ensure that the wax can adhere firmly to the hair. Coconut oil-based wax esters and polyurethane dispersions can improve the flexibility of depilatory wax, making it easier to apply and remove, and can also improve the stability of depilatory wax during storage to prevent it from hardening or deteriorating. Coconut oil-based wax esters can provide a smooth touch and a pleasant smell, improving the sensory experience when using depilatory wax. Coconut oil-based wax esters help promote the formation of a uniform and stable wax film on the wax-based substance, which can adhere firmly to the skin and hair, thereby improving the efficiency of depilatory.

[0038] (4) Glucoamylase can clean the pores, while keratinase and cellulase can soften the hair on the skin surface, making hair removal more efficient. Depilatory protease can gently decompose the hair cuticle, making it easier to pull out the hair and reducing skin damage. DETAILED DESCRIPTION

[0039] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0040] In the following examples and comparative examples, the sources of the reagents used are as follows:

[0041] Immobilized lipase

[0042] Immobilized lipase 1: the manufacturer is Shanghai Huashang Xiangyang Biotechnology Co., Ltd., the brand is Immobilizedlipase;

[0043] Immobilized lipase 2: the manufacturer is Shangke Biopharmaceutical (Shanghai) Co., Ltd., the brand is CALB;

[0044] Immobilized lipase 3: The manufacturer is Xiasheng (Beijing) Biotechnology Development Co., Ltd., and the brand name is GDG-2006.

[0045] Carboxylated cellulose nanocrystals: manufacturer is Shenzhen Huanuo Biotechnology Co., Ltd.;

[0046] Polyurethane dispersion: the manufacturer is Covestro Polymers (China) Co., Ltd., the brand is polyurethane-35;

[0047] Keratinase: The manufacturer is Weifang Ruichen Biotechnology Co., Ltd., the brand is RCJD20;

[0048] Glucoamylase: The manufacturer is Beijing Solebow Technology Co., Ltd., brand name is T8500;

[0049] Cellulase: purchased from Shanghai Lianmai Bioengineering Co., Ltd., model R-10BR, product number LM1031.

[0050] Unless otherwise specified, other materials, reagents, etc. used in the examples and comparative examples can be obtained from commercial sources.

[0051] Examples 1 to 18

[0052] The components of Examples 1 to 18 are shown in Table 1.

[0053] Table 1 Composition components and addition amounts of Examples 1 to 18 (parts by weight)

[0054]

[0055]

[0056] Wherein, the preparation method of the modified polyol comprises the following steps:

[0057] (1) 200 parts of formic acid and 280 parts of hydrogen peroxide were mixed in 250 mL of dichloromethane to obtain a reaction mixture; the mixing temperature was 50° C.;

[0058] (2) The reaction mixture was cooled in an ice bath at 0° C., the reaction mixture and triglyceride were mixed, and then reacted at 50° C. for 2 h, and then the reactant was taken out and filtered. After the precipitate was taken out, it was washed with water, saturated sodium bicarbonate, and water in sequence, and epoxidized triglyceride was obtained after rotary evaporation. The specific infrared spectrum data are as follows:

[0059] δ=5.2(m,0.68H,m,-OCH 2 CH(OH)CH 2 O-),4.4–4.2(1.0H,dd,AOCH2CH(OH)

[0060] -),4.2–4.0(1.1H,dd,-OCH 2 CH(OH),2.8(0.35H,m,-CH 2 CH 2 (O)CH 2 -),2.7–2.4(1.2H,m,-CH 2 CH 2(O)CH2-),2.4–2.2(dd,3.3H),1.6(6H,br,(O=)CH 2 CH 2 -)1.38–1–20(m,26.0H,m,CH 2 ),1.0–0.9[0.93H,t,CH3(C9=C3)],0.9–0.8[1.25H,t,CH3(C9=C9)].

[0061] (3) 100 parts of epoxidized triglyceride were mixed with 50 mL of hydrochloric acid (37%) solution, and a hydroxylation synthesis reaction was carried out at 50° C. and a rotation speed of 600 rpm / min for 10 hours. After the reaction was completed, the mixture was filtered, and the precipitate was washed with water, saturated sodium bicarbonate, and water in sequence. After rotary evaporation and drying, the modified polyol was obtained. The specific infrared spectrum data are as follows:

[0062] δ=5.2[m,1H,m,-OCH 2 CH(OH)CH 2 O-],4.4–4.2[2.7H,dd,-OCH 2 CH(OH),

[0063] 4.2–4.0(2.7H,dd,-OCH 2 CH(OH)],4.0–3.9[1.6H,m,HOCH 2 CH(Cl)CH 2 -],3.8–3.6[m,3.4H,HOCH 2 CH(Cl)CH 2 -],2.4–2.2[9.5H,dd,(O=)CCH 2 -],1.60[6H,br,(O=)CH 2 CH 2 -]1.38–1.23(64H,m,CH 2 )1.1–0.9[t,2.5H,CH 3 (C9=C3)],0.9–0.8[t,2.9H,CH 3 (C9=C9)].

[0064] The preparation method of the coconut oil-based wax ester comprises the following steps: mixing 150 μmol coconut oil and 450 μmol coconut alcohol in isopropane, adding 6U immobilized lipase, and performing alcoholysis reaction at 40°C for 20 hours to obtain the coconut oil-based wax ester. The immobilized lipase is immobilized lipase 1 and immobilized lipase 2 at a mass ratio of 1:0.5.

[0065] The obtained coconut oil-based wax ester was analyzed for its component content by gas chromatography-mass spectrometry, as shown in Table 2.

[0066] Table 2 Composition of coconut oil-based wax esters

[0067] Element Area proportion in coconut oil-based wax esters / % Palmityl valerate (28:0) 9.6 Lauric acid (30:1) 48.8 Oleyl Myristate (32:1) 16.2 Palmitic Acid Oil (34:1) 6.4 Oleyl oleate (36:2) 3.3 Oleyl Stearate (36:1) 1.7 Total 85.7

[0068] As shown in Table 2, the total wax esters in coconut oil-based wax esters account for 85%, and the main component is lauric acid ester, which is 48.8%, followed by oleyl myristate, palmityl valerate and palmitic acid oil. Therefore, lipase tends to catalyze the esterification of long-chain fatty acids.

[0069] The preparation method of the depilatory hot wax of embodiments 1 to 18 comprises the following steps:

[0070] S1, heating the wax-based substance, modified polyol, coconut oil-based wax ester and polyurethane dispersion at 190° C. until melted, and stirring them uniformly at a rotation speed of 10 rpm / min to obtain a first mixture;

[0071] S2, adding carboxylated cellulose nanocrystals, depilatory protease and colorant to the first mixture, heating and mixing at 95° C., cooling and forming, to obtain the rosin-free depilatory hot wax.

[0072] Embodiments 19 to 20

[0073] The differences between Examples 19 and 20 and Example 3 are that the immobilized lipases in Example 19 are immobilized lipase 1 and immobilized lipase 3 at a mass ratio of 1:0.5. The immobilized lipases in Example 20 are immobilized lipase 2 and immobilized lipase 3 at a mass ratio of 1:0.5.

[0074] Examples 21 to 24

[0075] The molar ratios of the raw materials coconut oil and coconut alcohol used in the preparation method of coconut oil-based wax ester are 1:1 (150 μmol: 150 μmol), 1:2 (150 μmol: 300 μmol), 1:4 (150 μmol: 600 μmol), and 1:5 (150 μmol: 750 μmol).

[0076] Comparative Example 1

[0077] The difference between Comparative Example 1 and Example 3 is that: in Comparative Example 1, no carboxylated cellulose nanocrystals are added.

[0078] Comparative Example 2

[0079] The difference between Comparative Example 2 and Example 3 is that: Comparative Example 2 does not add coconut oil-based wax ester.

[0080] Comparative Example 3

[0081] The difference between Comparative Example 3 and Example 3 is that: in Comparative Example 3, no coconut oil-based wax ester is added, and only 150 μmol coconut oil and 450 μmol coconut alcohol are added.

[0082] Comparative Example 4

[0083] The difference between Comparative Example 4 and Example 3 is that: Comparative Example 4 does not add depilatory protease.

[0084] Comparative Example 5

[0085] The difference between Comparative Example 5 and Example 3 is that: in Comparative Example 5, no modified polyol is added.

[0086] Comparative Example 6

[0087] The difference between Comparative Example 6 and Example 3 is that: Comparative Example 6 uses liquid fatty alcohol to replace the modified polyol.

[0088] The preparation method of liquid fatty alcohol comprises the following steps:

[0089] Under nitrogen, 5.8 parts of octadecyl alcohol were stirred at 40° C. and 10 rpm until liquid, 0.3 parts of polyoxyethylene ether were added, and stirring was continued for 10 minutes to obtain liquid fatty alcohol.

[0090] Comparative Example 7

[0091] The difference between Comparative Example 7 and Example 3 is that no polyurethane dispersion is added in Comparative Example 7.

[0092] Comparative Example 8

[0093] The difference between Comparative Example 8 and Example 3 is that in Comparative Example 8, the polyurethane dispersion is modified into an acrylic resin.

[0094] The preparation method of acrylic resin comprises the following steps: dissolving a chain initiator in acetone, and sequentially adding isobutylene, methyl acrylate, hydroxyethyl acrylate and trifluoroethyl methacrylate into a four-necked flask equipped with a mechanical stirrer, a reflux cold flow tube and a thermometer, then adding a chain transfer agent at a reaction temperature of 65°C, polymerizing for 7 hours, cooling the reaction liquid to room temperature, slowly pouring it into ethanol under mechanical stirring, filtering it with fine gauze, drying the filter residue in an oven at 80°C to constant weight, and finally crushing it to obtain acrylic resin.

[0095] Performance Testing

[0096] The depilatory wax samples of Examples 1 to 24 and Comparative Examples 1 to 8 were tested as follows:

[0097] 1. Drop melting point: According to GB-T8026-87, heat and melt the depilatory wax in the wax tank, then put the cooled thermometer vertically into the melted depilatory wax, so that the sample adheres to the thermometer ball, and put the thermometer with the sample in a test tube. When heated in a water bath, the sample melts until the first drop drips from the thermometer ball. At this time, the temperature of the thermometer is the drop melting point of the depilatory hot wax.

[0098] 2. Needle penetration: According to the standard of GB / T4985-2021, heat the prepared depilatory wax to the melting point and then pour it into the molder to cool and mold. Then, control the molded sample at 45°C in a water bath, and use the standard needle of the needle penetrometer to penetrate the sample for 5s under a load of 100g to measure its needle penetration.

[0099] 3. Contact angle test: It was carried out at ambient temperature using a Kruss DSA25 optical contact angle analyzer (Hamburg, Germany) using a 5 μL water droplet. Each sample was tested 5 times and the average value was taken.

[0100] 4. Hair removal effect and residual wax phenomenon: The test method is: take each group of hair removal hot wax solid, heat it to 60℃ to melt, apply it on the hair, wait for the wax film and hair to solidify into one, tear off the wax film and pluck the hair, and test its hair removal effect and residual wax. See Table 3 for details.

[0101] Table 3 Physical and chemical properties of samples in each group

[0102]

[0103]

[0104] As shown in Table 3, in the depilatory hot wax, a higher water contact angle indicates that the wax has better hydrophobicity, which helps the wax to be more easily removed from the skin after use, but a high contact angle is not conducive to the adhesion of the wax to the wet skin surface, so the water contact angle affects the cleanliness and skin adhesion of the wax. Depilatory hot wax needs to be heated to an appropriate temperature for easy application. The drop melting point determines the heating temperature range of the wax and affects its fluidity and adhesion on the skin, that is, the drop melting point affects the heating and use temperature of the wax, as well as the mildness to the skin. The preferred drop wax point should be 40°C to 50°C to ensure that the wax can remain liquid after heating, which is easy to apply without scalding the skin. Needle penetration is an indicator of the hardness of the wax. A high needle penetration indicates that the wax is softer and easier to apply and penetrate between the hairs. A low needle penetration indicates that the wax is harder, which provides better structural stability. In depilatory hot wax, an appropriate needle penetration helps the wax to be evenly applied to the skin and adhere to the hair. Combined with the depilatory effect, a suitable depilatory effect can be obtained. Penetration affects the spreadability of the wax and its ability to capture hair.

[0105] The depilatory hot wax of Examples 1 to 24 can achieve the effect of no residual hair and no residual wax during use, indicating that they have good depilatory effects.

[0106] Examples 3 and 4 to 14 are mainly to explore the effects of different types of wax on the performance of hot wax for hair removal. The single polyethylene wax and polypropylene wax have better hydrophobicity but lower viscosity, but their drop melting point is higher, and they are more irritating to the skin. Beeswax has higher viscosity and lower drop melting point, but lower hydrophobicity. Therefore, the present invention uses beeswax and microcrystalline wax as wax-based substances. On the basis of having a good hair removal effect, they have better affinity for the skin, and the drop melting point is within 40 to 50°C, which can reduce skin irritation and pain. Compared with the composite wax in Example 3, its use temperature is higher,

[0107] The purpose of the depilatory wax of Examples 15 to 18 and Example 3 is to explore the effect of the mass ratio range of beeswax and microcrystalline wax on performance. Combined with the data, it can be seen that a composition of beeswax and microcrystalline wax with a mass ratio of (3 to 5): 1 can obtain a depilatory hot wax with better performance.

[0108] The purpose of Examples 21 to 24 is to explore the effect of the molar ratio of the raw materials coconut oil and coconut alcohol used in the preparation method of coconut oil-based wax esters on the product performance. When the molar ratio of coconut oil to coconut alcohol is in the range of 1: (2 to 4), the initial reaction rate increases sharply with the increase of substrate concentration, because the enzyme is saturated with substrate, resulting in effective binding and high conversion rate reaching the maximum rate. Therefore, at low substrate concentrations (1: 1), the content of wax esters generated is insufficient. At high substrate concentrations (1: 5), the more impurities in the residual substrate, the lower the content of wax esters.

[0109] The depilatory hot wax of Comparative Example 1 does not add cCNCs, so its adhesion performance is significantly reduced and its needle penetration is improved, indicating that the carboxyl functional groups on the surface of cCNCs react with the modified polyols and coconut oil-based wax esters to form hydrogen bonds, respectively, to improve the structural stability of the depilatory hot wax, so that the wax maintains its integrity when removing hair and reduces breakage.

[0110] Comparative Example 2 does not add coconut-based wax alcohol, so its drop melting point is significantly reduced, and its needle penetration is also reduced, but its depilatory effect is not good, and there are still residual hair residues. This is because coconut-based wax alcohol is a class of ester compounds with a higher melting point, and they can improve the hardness and stability of wax in depilatory wax. In addition, coconut-based wax alcohol may have a significant effect on improving the hydrophobicity of depilatory wax, and it is easy to remove residual wax after use. The lubrication of coconut oil-based wax ester helps to reduce the discomfort in the depilatory process, and can also improve the ductility of depilatory wax, making it easier to evenly cover on the skin, reducing friction and stimulation to the skin.

[0111] Comparative Example 3 does not add coconut wax alcohol, but only adds 150 μmol coconut oil and 450 μmol coconut alcohol. It helps to improve the texture of the depilatory wax and makes it easier to apply on the skin. The fatty acid components in coconut oil contribute to the viscosity of the depilatory wax to a certain extent, but not as strong as coconut wax alcohol, so coconut oil and coconut alcohol can only improve the skin feel, improve the spreadability and easy cleaning effect. Its depilatory effect is not as good as coconut wax alcohol.

[0112] Comparative Example 4 does not add depilatory protease, which has no significant effect on the drop melting point and contact angle of the depilatory hot wax. This is because saccharifying enzyme can clean the pores, keratinase and cellulase can soften the hair on the skin surface, thereby making the depilatory efficiency higher.

[0113] Comparative Example 5 does not add modified polyols, and the needle penetration is lower, that is, the hardness is higher, and there are residual hairs after depilation, which shows that the modified polyols increase the polar groups in the molecules through the hydroxylation reaction and improve the interaction with the hair. The addition of modified polyols can change the rheological properties of the depilatory wax, making it more suitable for depilatory operations and improving the depilatory effect.

[0114] Comparative Example 6 uses liquid fatty alcohol to replace modified polyols. As a long-chain fatty alcohol, octadecyl alcohol can increase the viscosity and spreadability of depilatory wax in depilatory hot wax, and improve its adhesion to the skin. Its long-chain structure may help to form a protective film around the hair, thereby reducing skin irritation during depilatory. However, the melting point of octadecyl alcohol itself is relatively high (59.4-59.8°C), which increases the overall melting point of depilatory wax. Therefore, epoxidized modified polyols are used as plasticizers in the present invention, which reduce the drop melting point of depilatory hot wax, making the wax easier to flow and apply at lower temperatures, so that the depilatory hot wax feels better.

[0115] Comparative Example 7 does not add polyurethane dispersion, resulting in reduced hydrophobicity and drop melting point of depilatory wax, and reduced needle penetration, indicating that its hardness is increased, but it is not possible to tear off the hot wax in one piece. This is because the polyurethane dispersion increases the hydrophobicity and drop melting point of the depilatory wax, thereby increasing the water contact angle. This helps to easily clean and remove residual wax after use. The polyurethane dispersion also improves the softness and ductility of the depilatory wax, improves the spreadability of the depilatory wax and its adhesion to the skin. The polyurethane dispersant can improve the uniform film-forming ability of the depilatory wax on the skin surface, forming a continuous, uniform and elastic film, which helps to more effectively adhere to the hair, and the wax can be torn off in one piece when torn off, so that it can remove the hair more thoroughly.

[0116] Comparative Example 8 replaces the polyurethane dispersion with an acrylic resin, and its hydrophobicity is significantly improved, and the drop melting point is also increased, indicating that the addition of the polyurethane dispersion can reduce the irritation and pain of hair removal compared with Example 3. Moreover, when the hair removal effect is equivalent, the contact angle of Comparative Example 8 is higher than that of Example 3, which is not conducive to the adhesion of the wax to the wet skin surface, so it affects the adhesion of the wax to the skin.

[0117] In summary, the main components of the depilatory hot wax of the present invention are wax-based substances, carboxylated cellulose nanocrystals (cCNCs), coconut oil-based wax esters, depilatory proteases, epoxidized polyols and polyurethane dispersions, and no additives containing any rosin or rosin derivatives using rosin as a raw material are added, thereby avoiding the occurrence of users being allergic to rosin and its derivatives, and the depilatory hot wax has high depilatory efficiency, low drop melting point, can significantly reduce skin pain, and has good film-forming properties and is easy to tear.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A rosin-free hot wax for hair removal, characterized in that: The invention comprises the following raw materials in parts by weight: 30-70 parts of wax-based substances, 1-5 parts of carboxylated cellulose nanocrystals, 3-7 parts of coconut oil-based wax esters, 0.1-1 parts of depilatory protease, 5-10 parts of modified polyols, 3-5 parts of polyurethane dispersions and 0.3-2 parts of colorants; wherein the coconut oil-based wax esters are synthesized from coconut oil, coconut alcohol and immobilized lipase; and the modified polyols are synthesized from triglycerides through epoxidation reaction and then hydroxylation reaction.

2. The rosin-free hair removal hot wax according to claim 1, characterized in that: The preparation method of the modified polyol comprises the following steps: (1) mixing formic acid and hydrogen peroxide to obtain a reaction mixture; (2) cooling the reaction mixture, mixing the reaction mixture and triglyceride, and then reacting, then taking out the reactant for filtering, taking out the precipitate for washing, and drying to obtain epoxidized triglyceride; (3) mixing the epoxidized triglyceride with the acid solution to carry out a hydroxylation synthesis reaction, filtering after the reaction is completed, taking out the precipitate, washing it, and drying it to obtain the modified polyol.

3. The rosin-free hot wax for hair removal according to claim 2, characterized in that: The parameters in the preparation method of the modified polyol are selected from at least one of (I) to (VI): (I) the mass ratio of triglyceride to formic acid and hydrogen peroxide is 1:(0.9-1.2):(1.2-1.5); (II) The mixing temperature in step (1) is 45 to 55° C. and the mixing time is 10 to 20 min; (III) In step (2), the reaction mixture is cooled to 0-10°C; (IV) In the step (2), the reaction temperature is 45-55°C and the reaction time is 1-2h; (V) the mass ratio of epoxidized triglyceride to acid solution is (9-11):1; (VI) The reaction temperature of the hydroxylation synthesis reaction is 45 to 55° C. and the reaction time is 18 to 20 hours.

4. The rosin-free hot wax for hair removal according to claim 1, characterized in that: The preparation method of the coconut oil-based wax ester comprises the following steps: mixing coconut oil and coconut alcohol, adding immobilized lipase to carry out alcoholysis reaction, and obtaining the coconut oil-based wax ester.

5. The rosin-free hot wax for hair removal according to claim 4, characterized in that: The parameters of the preparation method of the coconut oil-based wax ester are selected from at least one of (I) to (III): (I) the molar ratio of coconut oil to coconut alcohol is 1:(2-4); (II) the alcoholysis reaction is carried out at a temperature of 30 to 45°C and for a time of 18 to 24 hours; (III) The added amount of the coconut oil and the immobilized lipase is (100-110) mg: (5-10) U.

6. The rosin-free hot wax for hair removal according to claim 1, characterized in that: The wax-based substance is at least one of paraffin wax, microcrystalline wax, beeswax, wood wax, polyethylene wax, polypropylene wax, palm wax, carabar wax and castor wax.

7. The rosin-free hot wax for hair removal according to claim 1, characterized in that: The wax-based substance is a composition of beeswax and microcrystalline wax in a mass ratio of (3-5):1; and / or the dehairing protease is keratinase, saccharifying enzyme and cellulase in a mass ratio of 1:1:

1.

8. The method for preparing rosin-free hot wax for hair removal according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, heating the wax-based substance, modified polyol, coconut oil-based wax ester and polyurethane dispersion until they are melted, and stirring them evenly to obtain a first mixture; S2, adding carboxylated cellulose nanocrystals, depilatory protease and colorant to the first mixture, heating and mixing, cooling and forming, to obtain the rosin-free depilatory hot wax.

9. The method for preparing rosin-free hot wax for hair removal according to claim 8, wherein: In the step S1, the heating temperature is 180-200°C; and / or, in the step S2, the heating temperature is 90-100°C.

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