Phase change cream composite material and preparation method thereof

Abstract

The invention discloses a phase-change cream composite material and a preparation method thereof. The phase-change cream composite material comprises the following raw materials in percentage by weight: 10-60% of a phase-change material, 1.5-7% of an emulsifier, 0-2% of a thickening agent, 4-10% of an emulsion stabilizer, 0.5-4% of phase-change gel, 0.05-0.2% of a preservative and the balance of water, the cream composite material is an oil-in-water system; the phase change material exists in a cream system in the form of dispersed gel droplets, and forms a continuous cream composite material with a water phase. The phase-change cream composite material prepared by the invention is high in stability, good in dispersity, good in softness and small in flowability, and different product forms can be designed according to cold compress and hot compress parts of a human body.

Description

Technical Field

[0001] The present invention relates to the technical field of phase change materials, and particularly to a phase change cream composite material and a preparation method thereof. Background Art

[0002] Due to seasonal temperature changes, environmental temperature, and abnormal physical conditions of the human body, body temperature may increase, or the body may be fatigued and require items to cool down and relieve discomfort. Although air conditioners and fans can cool down, they are not convenient to carry; in addition, some cooling sprays can also achieve the effect, but the ingredients added therein contain volatile components such as alcohol or butane, which belong to flammable and explosive substances, and the cooling effect lasts for a very short time. Improper use may also cause local frostbite.

[0003] Phase change materials are currently a type of energy storage material that is widely used in research. They store and release energy by utilizing the physical state change of the material. Among them, solid-liquid phase change materials are more commonly used in conventional daily products, mainly releasing heat from the liquid phase to the solid phase and absorbing heat from the solid phase to the liquid phase. When the phase change material reaches a temperature above the phase change temperature, it becomes a liquid, and when the temperature is lower than the phase change temperature, it releases heat and becomes a solid. In the liquid state, the phase change material has strong fluidity, which requires high packaging materials to prevent leakage; in the solid state, the phase change material is hard, and the inner material is easily broken into small pieces, and the comfort for human body cooling is not good.

[0004] JP2021056135 discloses a neck cooling tool wound around the human neck, which uses a phase change material to absorb heat from the solid state to the liquid state to achieve the purpose of cooling the human body. The inner material is a phase change material (PCM), which can ultimately become a liquid phase after absorbing heat. This phase change material in the liquid phase state has great fluidity and is prone to the risk of leakage. Moreover, under the influence of gravity, the flowing liquid is likely to cause the material to concentrate at the lower end of the product packaging, while there is a cavity at the upper end, resulting in uneven temperature distribution. And in the solid state, this product is very hard, and it is relatively rigid when worn around the neck, with poor comfort.

[0005] CN201811277314.0 discloses a segmented heat storage composite phase change material and a preparation method thereof. By heating and melting an organic phase change material, adding an emulsifier, and stirring to obtain a uniform mixture; heating a hydrated salt phase change material to melting, adding a nucleating agent, controlling the temperature of the hydrated salt phase change material to be the same as the temperature of the mixture, and stirring to make the hydrated salt phase change material and the nucleating agent evenly mixed; an oil-in-water type phase change emulsion is obtained, and a solid segmented heat storage composite phase change material is obtained. This invention adopts an oil-in-water system with the outer phase being oil, and the phase change material is also in the outer phase. Below the phase change temperature, the outer phase will become solid, and the whole material will still be hard, unable to solve the pain point and characteristic of needing to remain soft during use. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a phase change cream composite material and a preparation method thereof. The content range of the phase change material in the phase change cream is wide, up to 10-60%, and the content of the appropriate phase change material can be selected according to the use scenario to achieve appropriate cooling performance, and it has good stability.

[0007] The technical solution adopted by the present invention to solve the technical problems is: a phase change cream composite material, comprising the following raw materials in weight percentages: 10-60% of a phase change material, 1.5-7% of an emulsifier, 0-2% of a thickener, 4-10% of an emulsion stabilizer, 0.5-4% of a phase change gelling agent, 0.05-0.2% of a preservative, and water to make up 100%; the cream composite material is an oil-in-water system; the phase change material exists in the form of dispersed gel droplets in the cream system and forms a continuous cream composite material with the water phase.

[0008] The raw material ratio of the phase change cream composite material is further limited, comprising the following raw materials in weight percentages: 20-55% of a phase change material, 4-6% of an emulsifier, 0-1.2% of a thickener, 5-9% of an emulsion stabilizer, 0.9-3.5% of a phase change gelling agent, 0.06-0.1% of a preservative, and water to make up 100%.

[0009] Further, the phase change material is an organic phase change material, and the phase change material is one or any mixture of two or more of alkanes C n H 2n+2 with n = 14-18 carbon atoms; or the phase change material is one or any mixture of two or more of ester compounds C m H 2m+1 COOCH3, C m H 2m+1 COOC2H5; or the phase change material is a mixture of any two components or two or more of the above-mentioned alkanes and ester compounds.

[0010] Further, the phase change gelling agent is a styrene block copolymer (SBCs), including any one or any mixture of two or more of styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene (SIS), styrene-ethylene-propylene-styrene block copolymer (SEPS), polystyrene-polyethylene-polybutene-polystyrene block copolymer, hydrogenated polystyrene-polyisoprene-polystyrene, and polystyrene-polyethylene-polypropylene block copolymer.

[0011] Further, the emulsifier is one of sodium dodecyl sulfate, sodium dodecyl polyether sulfate, and sodium dodecylbenzenesulfonate, or a mixture of two of them, or a mixture of all three; the thickener is one of hydroxyethyl cellulose, carboxymethyl cellulose, ethyl cellulose, and hydroxypropyl methyl cellulose, or a mixture of two or more components; the emulsion stabilizer is one of cetearyl alcohol, beeswax, and glyceryl stearate, or a mixture of two of them, or a mixture of all three; the preservative is one of methylisothiazolinone, methylchloroisothiazolinone, 2-bromo-2-nitropropane-1,3-diol, and iodopropynyl butylcarbamate, or a mixture of two or more components.

[0012] Further, the composition of the phase change cream composite material further includes pigments, fragrances or essential oils.

[0013] Further, the phase change cream composite material can be combined with packaging materials to form a temperature control product for cold compress or hot compress; according to the parts of the human body that need to be cooled or hot compressed, it can be arbitrarily combined, structured, and externally changed with the packaging materials, including cold and hot compress physiotherapy packs, cooling mats, cooling pads, cooling eye masks, cooling collars, cooling vests, cooling hats, and forehead cooling bands.

[0014] Among them, for the cooling mats and cooling pads, they can be made into square sheet-like bags, with internal partitions to form independent spaces; for the cooling eye masks and forehead cooling bands, according to the range of the eyes or the width of the forehead, they can be made into oval sheet-like bags or rectangular bags, and are designed with binding straps for easy use; for the cooling vests, the film bags are made into corresponding shapes according to the size of the human back and chest, and the film bags can be partitioned into independent spaces; for the cooling collars, they can be U-shaped or strip-shaped for easy wearing.

[0015] A preparation method of a phase change cream composite material has two preparation methods according to whether a thickener is added or not according to the formula requirements.

[0016] Method 1, the formula does not contain a thickener, and the specific preparation method includes the following steps:

[0017] Step 1), Weigh each raw material according to the weight percentage.

[0018] Step 2), Add the phase change material, emulsion stabilizer, and phase change gel agent into a container and mix them. Stir and dissolve at a temperature of 80 - 85 °C, and disperse evenly to form an oil phase.

[0019] Step 3), Add water and emulsifier into another container and mix them. Stir and disperse evenly at a temperature of 80 - 85 °C to form an aqueous phase.

[0020] Step 4), at 80 - 85°C, after the aqueous phase is completely dissolved, under stirring, slowly add the completely dissolved oil phase. After the oil phase and the aqueous phase are completely mixed, carry out heat preservation and homogenization. The homogenization speed is 1200 - 2000 rpm, and the emulsification time is 15 - 30 min;

[0021] Step 5), after the emulsification is completed, stir and defoam under vacuum, cool down. When the temperature drops to about 40°C, add preservatives and required additives, stir evenly, and obtain the phase change cream.

[0022] Method 2, the formula contains a thickener, and the specific operation steps are as follows:

[0023] Step 1), weigh each raw material according to the weight percentage;

[0024] Step 2), add the phase change material, emulsification stabilizer, and phase change gel agent into a container and mix. Stir and dissolve at 80 - 85°C, disperse evenly to form an oil phase;

[0025] Step 3), add water and emulsifier into another container and mix. Stir and disperse evenly at 80 - 85°C to form an aqueous phase;

[0026] Step 4), at 80 - 85°C, after the aqueous phase is completely dissolved, under stirring, slowly add the completely dissolved oil phase. After the oil phase and the aqueous phase are completely mixed, carry out heat preservation and homogenization. The homogenization speed is 1200 - 2000 rpm, and the emulsification time is 15 - 30 min;

[0027] Step 5), after the emulsification is completed, stir and defoam under vacuum, cool down. When the temperature drops to about 40°C, add preservatives and required additives, stir evenly, and obtain the phase change cream;

[0028] Step 6), weigh the remaining water and thickener according to the formula, heat and stir, raise the temperature to 60 - 70°C. After the material thickens, cool down for later use;

[0029] Step 7), stir and mix the phase change cream obtained in step 5) and the material obtained in step 6) evenly to obtain the phase change cream containing a thickener.

[0030] The phase change cream can be canned at room temperature without heating or high temperature, which can reduce energy consumption.

[0031] The method for investigating the emulsification stability of the phase change cream composite material prepared by the present invention is as follows:

[0032] 1) Centrifugation method: Take an appropriate amount of the sample and place it in a centrifuge tube, seal it, place it in a constant temperature oven at 45°C for 1 h, then transfer it to a high-speed centrifuge and centrifuge at a speed of 3000 r / min for 30 min. Observe the state of the cream. If there is no oil separation on the surface of the material, it is stable.

[0033] 2) High and low temperature cycle test: Take multiple groups of samples and place them at 45°C, 4°C, -18°C, 45 to -18°C cycle (once every 48 hours), and at room temperature for 3 months. Observe once a week. If the material does not show stratification and oil separation, it is considered stable.

[0034] The beneficial effects of the present invention are as follows: Compared with the prior art, the phase change cream composite material and its preparation method provided by the present invention have the following advantages:

[0035] 1) The phase change cream composite material of the present invention is an oil-in-water system. The purpose of the oil-in-water system is to wrap the organic phase change material inside the water phase, so that the entire composite material remains in a soft state below the phase change temperature of the phase change material; before and after the phase change temperature, the morphology of the product does not change at all, and it is in a soft cream state. While the traditional phase change materials are generally in a solid-liquid state before and after the phase change temperature, the solid state is relatively hard and the liquid state has large fluidity; the phase change cream composite material can solve the disadvantage that the traditional organic phase change material becomes hard after absorbing heat, and increase the comfort of the product for human use; another point is that the phase change cream composite material has a certain consistency, which can reduce the risk of large-scale leakage and flow of the traditional phase change material inside the product once the packaging is damaged.

[0036] 2) Under the same conditions, compared with the traditional phase change material, when converted into the same content of the phase change material, the phase change cream composite material has stronger cooling performance and shorter solidification time. This is mainly because the phase change material forms dispersed fine gel droplets in the cream system, forming a continuous overall structure with the outer phase (water phase), making its cooling performance better. And the short solidification time is also because there are emulsifiers around the phase change material droplets in the phase change cream composite material, forming a certain number of crystal nuclei, which makes it easier for the phase change material to release heat and solidify.

[0037] 3) The density change of the phase change cream composite material before and after the phase change is very small, while the traditional phase change material is prone to cavities or pits in the product due to density changes during solid-liquid phase transition. The certain softness of the phase change cream composite material can well avoid this risk.

[0038] 4) By adding a phase change gelling agent to the organic phase change material, the phase change cream composite material composed of the emulsifier and water has good emulsion stability. After long-term thermal cycling and storage, the composite material can still maintain stability. This is because the addition of the phase change gelling agent causes the organic phase change material to form a micro-droplet emulsion when emulsified at high temperature. When the temperature drops below the gel point, gelation occurs inside the droplet emulsion, forming an organic gel microemulsion. When stored at room temperature, the gel microemulsion droplets are stable microgels, and it is not easy for the droplets to coalesce, thus improving the stability of the phase change cream.

[0039] 5) During the preparation of the phase change cream composite material of the present invention, only homogenization is required after the water phase and the oil phase are mixed to form an emulsion; there is no need to add initiators and monomers to initiate polymerization like traditional phase change material emulsions, and no other energy consumption is required. Description of the Drawings

[0040] Figure 1 It is the heating curve graph (4°C to 35°C) of Examples 1 to 6 and Comparative Example 1 in the present invention.

[0041] Figure 2 It is the cooling curve graph (35°C to 4°C) of Examples 1 to 6 and Comparative Example 1 in the present invention.

[0042] Figure 3 It is the heating curve graph (-20°C to 35°C) of Examples 7 to 9 and Comparative Examples 2 to 4 in the present invention.

[0043] Figure 4 It is the cooling curve graph (25°C to -20°C) of the products of Examples 7 to 9 and Comparative Examples 2 to 4 in the present invention. Detailed Embodiments

[0044] The present invention will be further described below through specific examples. However, these examples are only used to illustrate the present invention and not to limit the scope of the present invention.

[0045] Example 1

[0046] Weigh by weight percentage. Put 10% of n-octadecane, 4% of cetearyl alcohol, and 0.5% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) in a beaker, and slowly heat it to 80°C to 85°C until completely dissolved; put 3% of sodium dodecyl sulfate and 82.4% of water in a beaker, and slowly heat it to 80°C to 85°C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool it to 40°C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0047] Example 2

[0048] Weigh by weight percentage. Put 20% of n-octadecane, 5% of cetearyl alcohol, and 0.9% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) in a beaker, and slowly heat it to 80°C to 85°C until completely dissolved; put 5% of sodium dodecyl sulfate and 69% of water in a beaker, and slowly heat it to 80°C to 85°C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool it to 40°C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0049] Example 3

[0050] Weigh by weight percentage. Put 30% of n-octadecane, 6% of cetearyl alcohol, and 1.3% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; put 4% of sodium dodecyl sulfate and 58.6% of water into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0051] Example 4

[0052] Weigh by weight percentage. Put 40% of n-octadecane, 7% of cetearyl alcohol, and 1.7% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; put 4.5% of sodium dodecyl sulfate and 46.7% of water into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0053] Example 5

[0054] Weigh by weight percentage. Put 48% of n-octadecane, 7.5% of cetearyl alcohol, and 2.2% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; put 5% of sodium dodecyl sulfate and 37.2% of water into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0055] Example 6

[0056] Weigh by weight percentage. Put 60% of n-octadecane, 8% of cetearyl alcohol, and 2.5% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; put 5% of sodium dodecyl sulfate and 24.4% of water into a beaker, and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.1% of the aqueous solution of the mixture of methylisothiazolinone and methylchloroisothiazolinone as a preservative.

[0057] Example 7

[0058] Weigh by weight percentage. Put 48% of n-tetradecane, 8% of cetearyl alcohol, and 3% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; put 5% of sodium dodecyl sulfate and 35.92% of water into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After the emulsification is completed, cool down to 40 °C and add 0.08% of an aqueous solution of a mixture of preservatives methylisothiazolinone, methylchloroisothiazolinone, and 2-bromo-2-nitropropane-1,3-diol.

[0059] Example 8

[0060] Weigh by weight percentage. Put 48% of n-hexadecane, 8% of cetearyl alcohol, and 3% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; put 5% of sodium dodecyl sulfate and 35.92% of water into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After the emulsification is completed, cool down to 40 °C and add 0.08% of an aqueous solution of a mixture of preservatives methylisothiazolinone, methylchloroisothiazolinone, and 2-bromo-2-nitropropane-1,3-diol.

[0061] Example 9

[0062] Weigh by weight percentage. Put 15% of n-tetradecane, 33% of n-hexadecane, 8% of cetearyl alcohol, and 3% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; put 5% of sodium dodecyl sulfate and 35.92% of water into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After the emulsification is completed, cool down to 40 °C and add 0.08% of an aqueous solution of a mixture of preservatives methylisothiazolinone, methylchloroisothiazolinone, and 2-bromo-2-nitropropane-1,3-diol.

[0063] Example 10

[0064] Weigh by weight percentage. Put 30% of methyl palmitate, 6% of beeswax, and 4% of styrene-isoprene-styrene (SIS) into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; put 3% of sodium dodecyl polyether sulfate and 56.9% of water into a beaker and slowly heat it to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After the emulsification is completed, cool down to 40 °C and add 0.1% of an aqueous solution of methylisothiazolinone preservative.

[0065] Example 11

[0066] Weigh by weight percentage. Put 35% of ethyl palmitate, 7% of emulsifying stabilizer (4% of cetearyl alcohol and 3% of beeswax), and 3.5% of styrene-butadiene-styrene block copolymer (SBS) into a beaker, and slowly heat to 80°C - 85°C until completely dissolved; put 4% of sodium dodecyl sulfate and 50.4% of water into a beaker, and slowly heat to 80°C - 85°C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After emulsification is completed, cool to 40°C and add 0.1% of the aqueous solution of the preservative methylisothiazolinone.

[0067] Example 12

[0068] In the first step, weigh by weight percentage. Put 42% of n-octadecane, 3.9% of cetearyl alcohol, 2.1% of glyceryl stearate, and 1.6% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) into a beaker, and slowly heat to 80°C - 85°C until completely dissolved; put 2.1% of sodium dodecyl sulfate and 22.2% of water into a beaker, and slowly heat to 80°C - 85°C until completely dissolved; slowly add the oil phase to the stirred water phase for emulsification and homogenization. After emulsification is completed, cool to 40°C and add 0.1% of the aqueous solution of the mixture of the preservatives methylisothiazolinone and methylchloroisothiazolinone.

[0069] In the second step, weigh 25% of water and 1% of hydroxypropyl methylcellulose into a beaker, heat and stir to 65°C. Wait until the material becomes completely gelatinous and then cool to room temperature. In the third step, add the emulsified phase change material to the cellulose gel and stir evenly.

[0070] Comparative Example 1

[0071] The traditional phase change material n-octadecane.

[0072] Comparative Example 2

[0073] The traditional phase change material n-tetradecane.

[0074] Comparative Example 3

[0075] The traditional phase change material n-hexadecane.

[0076] Comparative Example 4

[0077] Weigh by weight percentage. Mix 15% of n-tetradecane and 33% of n-hexadecane by weight ratio.

[0078] Comparative Example 5

[0079] Weigh by weight percentage. Take 50% of n-octadecane and 10% of cetearyl alcohol in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; take 6% of sodium lauryl sulfate and 33.88% of water in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.12% of the aqueous solution of iodopropynyl butylcarbamate as a preservative.

[0080] Comparative Example 6

[0081] Weigh by weight percentage. Take 30% of n-octadecane and 2% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; take 4% of sodium lauryl sulfate and 63.88% of water in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.12% of the aqueous solution of iodopropynyl butylcarbamate as a preservative.

[0082] Comparative Example 7

[0083] Weigh by weight percentage. Take 50% of n-octadecane, 4% of cetearyl alcohol, and 2% of hydrogenated styrene-butadiene-styrene block copolymer (SEBS) in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; take 1.2% of sodium lauryl sulfate and 41.85% of water in a beaker, and slowly heat to 80 °C - 85 °C until completely dissolved; slowly add the oil phase to the stirred water phase, carry out emulsification, and carry out homogenization. After the emulsification is completed, cool down to 40 °C and add 0.15% of 2-bromo-2-nitropropane-1,3-diol as a preservative.

[0084] Stability test

[0085] 1) Centrifugation test:

[0086] Take appropriate samples of the phase change creams of Examples 1 - 12 and Comparative Examples 5 - 7 and place them in centrifuge tubes, seal them, and place them in a constant temperature oven at 45 °C for 6 h. Then transfer them to a high-speed centrifuge and centrifuge at a speed of 3000 r / min for 30 min. Observe the state of the cream. If there is no oil separation on the surface of the material, it is stable. The results are shown in Table 1.

[0087] Table 1. Centrifugation test results of the products of Examples 1 - 12 and Comparative Examples 5 - 7

[0088]

[0089] 2) High and low temperature cycle investigation:

[0090] Take multiple samples of the phase change creams of Examples 1-12 and Comparative Examples 5-7 and place them at 45°C, 4°C, -18°C, 45 to -18°C cycle (one cycle every 48 hours), and at room temperature for 3 months. Observe once a week. If the material does not show stratification or oil separation, it is considered stable. The results are shown in Table 2.

[0091] Table 2 High and low temperature cycle test results of the products of Examples 1-12 and Comparative Examples 5-7

[0092] 45℃ 4℃ -18℃ 45～-18℃ Normal temperature Example 1 Stable Stable Stable Stable Stable Example 2 Stable Stable Stable Stable Stable Example 3 Stable Stable Stable Stable Stable Example 4 Stable Stable Stable Stable Stable Example 5 Stable Stable Stable Stable Stable Example 6 Stable Stable Stable Stable Stable Example 7 Stable Stable Stable Stable Stable Example 8 Stable Stable Stable Stable Stable Example 9 Stable Stable Stable Stable Stable Example 10 Stable Stable Stable Stable Stable Example 11 Stable Stable Stable Stable Stable Example 12 Stable Stable Stable Stable Stable Comparative Example 5 Layering Stable Oil separation Layering Oil separation Comparative Example 6 Layering Stable Stable Oil separation Stable Comparative Example 7 Layering Stable Stable Layering Stable

[0093] 3) Product appearance:

[0094] Place Examples 1-12 and Comparative Examples 1-4 in a 4°C refrigerator. After the phase change materials have all completed phase change, touch the appearance softness of the products by hand. The results are shown in Table 3.

[0095] Table 3 Low temperature appearance test results of the products of Examples 1-12 and Comparative Examples 1-4

[0096] Soft / Hard Soft / Hard Example 1 Soft Example 9 Soft Example 2 Soft Example 10 Soft Example 3 Soft Example 11 Soft Example 4 Soft Example 12 Soft Example 5 Soft Comparative Example 1 Hard Example 6 Soft Comparative Example 2 Hard Example 7 Soft Comparative Example 3 Hard Example 8 Soft Comparative Example 4 Hard

[0097] 4) Cooling performance test:

[0098] Place the cooling samples of Examples 1-6 and Comparative Example 1 in the refrigerator freezer (0 to 4°C) to completely solidify them, and then place them in a 35°C constant temperature oven at the same time. Place the thermometer probe inside the material of the example and test the temperature change until the sample completely undergoes phase change. Characterize the cooling performance of the product by the duration of the sample near the phase change point through the temperature curve (as Figure 1 shown), and the test results are shown in Table 4 and Figure 1 .

[0099] Place the cooling samples of Examples 7-9 and Comparative Examples 2-4 in the refrigerator freezer (-20 to -18°C) to completely solidify them, and then place them in a 35°C constant temperature oven at the same time. Place the thermometer probe inside the material of the example and test the temperature change until the sample completely undergoes phase change. Characterize the cooling performance of the product by the duration of the sample near the phase change point through the temperature curve (as Figure 3 shown).

[0100] Table 4 Cooling performance test results of the products of Examples 1-6 and Comparative Example 1

[0101]

[0102] 5) Curing time test:

[0103] The curing time refers to the time when the phase change material releases heat and reaches a temperature below the phase change temperature. After the samples to be cured in Examples 1-6 and Comparative Example 1 are placed in an oven (35°C) until the complete phase change is finished, they are then simultaneously placed in the refrigerator freezer compartment (0-4°C). The thermometer probe is placed inside the material of the example to test the temperature change until the sample completely undergoes a phase change. The time during which the sample persists near the phase change point is characterized by the temperature curve (as shown in Figure 2 ) to characterize the curing time of the product. The test results are Figure 2 .

[0104] After the samples to be cured in Examples 7-9 and Comparative Examples 2-4 are placed in an oven (25°C) until the complete phase change is finished, they are then simultaneously placed in the refrigerator freezer compartment (-20 to -18°C). The thermometer probe is placed inside the material of the example to test the temperature change until the sample completely undergoes a phase change. The time during which the sample persists near the phase change point is characterized by the temperature curve (as shown in Figure 4 ) to characterize the curing time of the product. The test results are Figure 4 .

[0105] The above embodiments are only used to illustrate the present invention and are not intended to limit the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention. The scope of patent protection of the present invention shall be defined by the claims.

Claims

1. A phase change cream composite material, characterized in that: The raw materials include the following in weight percentages: phase change material 10-60%, emulsifier 1.5-7%, thickener 0-2%, emulsion stabilizer 4-10%, phase change gelling agent 0.5-4%, preservative 0.05-0.2%, and water to make up 100%; the cream composite material is an oil-in-water system; the phase change material exists in the form of dispersed gel droplets in the cream system, forming a continuous cream composite material with the aqueous phase.

2. The phase change cream composite material according to claim 1, wherein: The raw materials include the following in weight percentages: phase change material 20-55%, emulsifier 4-6%, thickener 0-1.2%, emulsion stabilizer 5-9%, phase change gelling agent 0.9-3.5%, preservative 0.06-0.1%, and water to make up 100%.

3. The phase change cream composite material according to claim 1, characterized in that: The phase change material is an organic phase change material, and the phase change material is one of alkanes C with the number of carbon atoms n = 14 - 18 n H 2n+2 or any mixture of two or more of them; or the phase change material is an ester compound C with the number of carbon atoms m = 11 - 15 m H 2m+1 COOCH3, C m H 2m+1 COOC2H5 or any mixture of two or more of them; or the phase change material is a mixture of any two components or more of the alkane and the ester compound.

4. The phase change cream composite material according to claim 1, characterized in that: The phase change gelling agent is a styrene block copolymer (SBCs), including any one or a mixture of any two or more of styrene-butadiene-styrene block copolymer (SBS), hydrogenated styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene (SIS), styrene-ethylene-propylene-styrene block copolymer (SEPS), polystyrene-polyethylene-polybutene-polystyrene block copolymer, hydrogenated polystyrene-polyisoprene-polystyrene, and polystyrene-polyethylene-polypropylene block copolymer.

5. The phase change cream composite material according to claim 1, wherein: The emulsifier is one of sodium dodecyl sulfate, sodium dodecyl polyether sulfate, and sodium dodecylbenzenesulfonate, or a mixture of two or all three of them; the thickener is one of hydroxyethyl cellulose, carboxymethyl cellulose, ethyl cellulose, and hydroxypropyl methyl cellulose, or a mixture of two or more components; the emulsion stabilizer is one of cetearyl alcohol, beeswax, and glyceryl stearate, or a mixture of two or all three of them; the preservative is one of methylisothiazolinone, methylchloroisothiazolinone, 2-bromo-2-nitropropane-1,3-diol, and iodopropynyl butylcarbamate, or a mixture of two or more components.

6. The phase change cream composite material according to claim 1, characterized in that: The composition of the phase change cream composite material also includes pigments, flavors, or essential oils.

7. The phase change cream composite material according to claim 1, wherein: The phase change cream composite material can be combined with packaging materials to form a temperature control product for cold compress or hot compress; according to the parts of the human body that need to be cooled or hot compressed, it can be combined with packaging materials in any combination, structure, and appearance change, including cold and hot compress physiotherapy packs, cooling mats, cooling pads, cooling eye masks, cooling collars, cooling vests, cooling hats, and forehead cooling bands.

8. The preparation method of a phase change cream composite material according to claim 1, characterized in that, The preparation method includes the following steps: Step 1), Weigh each raw material according to the weight percentage. Step 2), Add the phase change material, emulsion stabilizer, and phase change gelling agent into a container and mix them. Stir and dissolve them at a temperature of 80-85°C until they are evenly dispersed to form an oil phase. Step 3), Add water and emulsifier into another container and mix them. Stir and disperse them evenly at a temperature of 80-85°C to form an aqueous phase. Step 4), At 80-85°C, after the aqueous phase is completely dissolved, slowly add the completely dissolved oil phase under stirring. After the oil phase and the aqueous phase are completely mixed, carry out heat preservation homogenization, with a homogenization speed of 1200-2000 rpm and an emulsification time of 15-30 min. Step 5): After emulsification, stir under vacuum to defoam and cool down. When the temperature drops to about 40°C, add preservatives and required additives, and stir evenly to obtain the phase change cream.

9. The preparation method of a phase change cream composite material according to claim 8, wherein: The preparation method further includes Step 6): Weigh the remaining water and thickener according to the formula, heat and stir, raise the temperature to 60 - 70°C, and after the material thickens, cool it for standby; Step 7): Stir and mix the phase change cream obtained in Step 5) and the material obtained in Step 6) evenly to obtain the phase change cream containing thickener.

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