Temperature-sensitive material as well as preparation method and application thereof

Abstract

The invention provides a temperature-sensitive material as well as a preparation method and application thereof, and relates to the technical field of temperature response materials. The temperature-sensitive material comprises the following components in percentage by mass: 13-23% of a composite phase change material, 1-2% of a flexibilizer and the balance of a polymer base material, wherein the composite phase change material comprises paraffin and C17-C24 alkane. The gas permeability of the temperature-sensitive material provided by the invention has temperature responsiveness, and the effect of gas controlled release can be realized. For example, the temperature-sensitive material can be prepared into a temperature-sensitive film for wrapping an aromatherapy product for a clothes dryer, and when the temperature reaches a response temperature, the air permeability of the temperature-sensitive film is increased, so that volatile functional substances in the temperature-sensitive film are quickly released, and the treatment of clothes is realized; and when the temperature is lower than the response temperature, the air permeability of the temperature-sensitive film is reduced, and the release of volatile functional substances is reduced, so that the service life of the aromatherapy product is prolonged.

Description

Technical Field

[0001] This invention relates to the field of temperature-responsive materials technology, and in particular to a temperature-sensitive material, its preparation method, and its application. Background Technology

[0002] As users' needs for clothing care become more diversified, consumers are increasingly demanding higher standards for the health and odor of clothes dryers. They also have various drying needs, such as sterilization, deodorization, and cleaning. As a result, the latest clothes dryer products have provided solutions for these needs, but the actual results are not ideal.

[0003] To address the odor issues associated with dryers and the need for deodorizing clothes, many products on the market currently use aromatherapy to mask unpleasant smells. This aromatherapy is typically a hydrogel made from a mixture of fragrance substances, using gelatin, sodium alginate, carrageenan, and other base materials, which provides a certain degree of slow-release effect. Some aromatherapy products further add natural essential oils to enhance overall quality and achieve additional effects such as sterilization. In fact, natural essential oils have diverse functions, such as sterilization, deodorization, softening, anti-static, and anti-yellowing. However, most natural essential oils are volatile and have a short lifespan. To achieve the effects of natural essential oils, the aromatherapy product needs to be placed in the high-temperature, high-speed airflow of the dryer, which greatly shortens its lifespan, requiring frequent replacement by consumers. This increases the cost of clothing care, leads to a poor user experience, and limits the widespread application of this technology in dryer products. Summary of the Invention

[0004] To address the aforementioned technical problems, this invention provides a temperature-sensitive material, its preparation method, and its applications. This temperature-sensitive material exhibits temperature-responsive permeability, enabling controlled gas release. For example, it can be prepared as a temperature-sensitive membrane to encapsulate slow-release materials containing volatile functional substances, such as fragrances. When the temperature reaches its response temperature, the membrane's permeability increases, allowing the volatile functional substances inside to be released rapidly, thus treating clothing. When the temperature is below the response temperature, the membrane's permeability decreases, reducing the release of volatile functional substances and extending the lifespan of the slow-release material.

[0005] In a first aspect, the present invention provides a temperature-sensitive material, the temperature-sensitive material comprising the following components by mass percentage:

[0006] Composite phase change materials: 13-23%;

[0007] Toughening agent 1-2%;

[0008] Polymer substrate allowance;

[0009] The composite phase change material includes paraffin and C17-C24 alkanes.

[0010] In some embodiments of the present invention, the composite phase change material is composed of 60-90 wt% paraffin and 10-40 wt% C17-C24 alkanes.

[0011] In some embodiments of the present invention, the C17-C24 alkane is n-octadecane.

[0012] In some embodiments of the present invention, the toughening agent is one or more of maleic anhydride-grafted polyolefin, ethylene-vinyl acetate copolymer and ethylene-acrylic acid copolymer, preferably maleic anhydride-grafted polyolefin.

[0013] In some embodiments of the present invention, the polymer substrate is a polyolefin, preferably low-density polyethylene and / or polypropylene.

[0014] In some embodiments of the present invention, the molecular weight of the polymer substrate is 100,000 to 1,000,000.

[0015] In some embodiments of the present invention, the temperature-sensitive material further includes a thermally conductive material.

[0016] In some embodiments of the present invention, the thermally conductive material has a mass content of 3-6% in the temperature-sensitive material.

[0017] In some embodiments of the present invention, the particle size of the thermally conductive material is 1-10 μm.

[0018] In some embodiments of the present invention, the thermally conductive material includes thermally conductive ceramic materials and / or aminated thermally conductive ceramic materials.

[0019] In some embodiments of the present invention, the thermally conductive ceramic material includes one or more of hexagonal boron nitride (BN), silicon nitride (Si3N4), aluminum oxide (Al2O3), aluminum nitride (AlN), and silicon carbide (SiC).

[0020] In some embodiments of the present invention, the thermally conductive material is aminated hexagonal boron nitride. In some embodiments of the present invention, the temperature-sensitive material further includes an antioxidant and / or a reversible thermochromic material.

[0021] In some embodiments of the present invention, the antioxidant in the temperature-sensitive material has a mass content of 0.3-0.6%.

[0022] In some embodiments of the present invention, the antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], dilauryl thiodipropionate, 2,6-di-tert-butyl-4-methylphenol, butyl hydroxyanisole, and tert-butylhydroquinone.

[0023] In some embodiments of the present invention, the reversible thermochromic material has a mass content of 0.1-0.2% in the thermosensitive material.

[0024] Secondly, the present invention provides a method for preparing a temperature-sensitive material as described in the first aspect, the method comprising the following steps:

[0025] (1) Mix paraffin and C17-C24 alkanes evenly to obtain a composite phase change material;

[0026] (2) Optionally, the composite phase change material and the thermally conductive material are mixed evenly in an organic solvent and dried to obtain a modified phase change material;

[0027] (3) The composite phase change material or the modified phase change material is heated to a liquid state and mixed evenly with a polymer substrate, toughening agent, optional antioxidant and optional reversible thermochromic material. The mixture is then melt-extruded using a screw extruder to obtain the thermosensitive material.

[0028] In some embodiments of the present invention, the temperature during mixing in step (1) is 65-80°C.

[0029] In some embodiments of the present invention, the organic solvent is carbon tetrachloride.

[0030] In some embodiments of the present invention, the temperature during mixing in step (2) is 65-75°C.

[0031] In some embodiments of the present invention, the screw extruder in step (3) is a twin-screw extruder, the operating temperature range of the twin-screw extruder is 170-190℃, and the screw speed is 18-30r / min.

[0032] Thirdly, the present invention provides a temperature-sensitive film, wherein the material of the temperature-sensitive film is the temperature-sensitive material described in the first aspect.

[0033] Fourthly, the present invention provides an application of the temperature-sensitive material as described in the first aspect or the temperature-sensitive membrane as described in the third aspect in controlled gas release.

[0034] The technical solution provided by the embodiments of the present invention has the following advantages compared with the prior art:

[0035] The embodiments of the present invention obtain a temperature-sensitive material through the synergistic combination of various materials. Its air permeability is temperature-responsive, that is, when the temperature is lower than the response temperature, its air permeability is low; when the temperature rises to the response temperature, its air permeability increases rapidly; when the temperature drops below the response temperature again, its air permeability decreases rapidly.

[0036] The properties of the thermosensitive material of this invention enable its use in controlled gas release, for example, by preparing it into a thermosensitive membrane to encapsulate a slow-release material containing volatile functional substances for use in dryers. When the dryer is operating, the permeability of the thermosensitive membrane increases, allowing the volatile functional substances inside to be released quickly, thus treating the clothes; when the dryer stops operating, the permeability of the thermosensitive membrane decreases, reducing the release of volatile functional substances and thereby extending the service life of the slow-release material. Attached Figure Description

[0037] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0038] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1A This is a SEM image of the temperature-sensitive film provided in Embodiment 1 of the present invention;

[0040] Figure 1B This is a SEM image of a regular PP film.

[0041] Figure 2 Infrared spectra of the temperature-sensitive film, the composite phase change material OD / P, and the ordinary PP film provided in Embodiment 1 of the present invention;

[0042] Figure 3 This is a differential scanning spectral curve of the temperature-sensitive film provided in Embodiment 1 of the present invention;

[0043] Figure 4 This is a graph showing the air permeability of the temperature-sensitive membrane provided in Embodiment 1 of the present invention as a function of temperature. Detailed Implementation

[0044] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0045] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] In a first aspect, embodiments of the present invention provide a temperature-sensitive material, the temperature-sensitive material comprising the following components by mass percentage:

[0049] Composite phase change materials: 13-23%;

[0050] Toughening agent 1-2%;

[0051] Polymer substrate allowance;

[0052] The composite phase change material includes paraffin and C17-C24 alkanes.

[0053] In the temperature-sensitive material provided in this invention, the phase change material undergoes a solid-liquid or liquid-solid transition during the phase change process. This transition is accompanied by volume expansion or contraction, which in turn affects the microstructure of the temperature-sensitive material (such as pore size and distribution), thereby affecting its air permeability. Specifically, when the temperature rises to the phase change temperature, the phase change material melts from a solid to a liquid state, its volume expands, the pores inside the temperature-sensitive material increase, and the air permeability increases. When the temperature drops below the phase change temperature, the phase change material changes from a liquid to a solid state, its volume contracts, the pores inside the temperature-sensitive material decrease, and the air permeability decreases. Therefore, the air permeability of the temperature-sensitive material provided in this invention is temperature-responsive.

[0054] In this embodiment of the invention, the mass percentage of the composite phase change material can be any value within the range of 13-23%, such as 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, or 23%. If the content of the composite phase change material is too low, its influence on the air permeability of the temperature-sensitive material during phase change will be small, and the temperature response of the temperature-sensitive material will be weak. If the content of the composite phase change material is too high, the film-forming properties of the temperature-sensitive material will be poor, and the mechanical properties (such as tensile properties) and heat-sealing properties after film formation will be negatively affected. Moreover, during the phase change conversion process, leakage of the phase change material to the outside of the film may occur.

[0055] The toughening agent's mass percentage can be any value within the range of 1-2%, for example, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, or 2%. The main function of the toughening agent in temperature-sensitive materials is to improve the material's toughness, enhance the compatibility between the polymer substrate and the composite phase change material, and allow the composite phase change material to be uniformly distributed within the substrate. If the toughening agent content is too low, its effect on improving the toughness and impact resistance of the temperature-sensitive material will be minimal; if the toughening agent content is too high, it may affect the microstructure and porosity of the polymer substrate, ultimately affecting the gas permeability of the finished temperature-sensitive film and leading to increased production costs.

[0056] The C17-C24 alkanes refer to alkanes with 17-24 carbon atoms, such as heptadecane, octadecane, nonadecane, eicosane, docosane, tetradecane, etc. In this embodiment of the invention, for the purpose of reducing costs, the C17-C24 alkanes are preferably n-octadecane.

[0057] In some embodiments of the present invention, the composite phase change material is composed of 60-90 wt% paraffin and 10-40 wt% C17-C24 alkanes. The paraffin content in the composite phase change material can be, for example, 60 wt%, 62 wt%, 65 wt%, 68 wt%, 70 wt%, 72 wt%, 75 wt%, 78 wt%, 80 wt%, 82 wt%, 85 wt%, 88 wt%, or 90 wt%; the C17-C24 alkanes content in the composite phase change material can be, for example, 10 wt%, 12 wt%, 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, 30 wt%, 32 wt%, 35 wt%, 38 wt%, or 40 wt%.

[0058] In composite phase change materials, paraffin wax serves as the primary heat storage agent, while C17-C24 alkanes act as secondary heat storage agents. Paraffin wax alone has a phase change temperature above 50-60°C, is relatively inexpensive, and its phase change temperature range is close to the operating temperature of a clothes dryer. However, the phase change temperature of paraffin wax alone is fixed and cannot be freely adjusted according to requirements. In this invention, different proportions of paraffin wax and C17-C24 alkanes are used in combination. By controlling the ratio of these two components, the phase change temperature of the composite phase change material, i.e., the response temperature of the temperature-sensitive material, can be adjusted. Specifically, the lower the proportion of paraffin wax and the higher the proportion of C17-C24 alkanes, the lower the peak phase change temperature. In this invention, when the ratio of paraffin wax to C17-C24 alkanes is within the above-mentioned range, the response temperature of the temperature-sensitive material can be controlled between 40-65°C, which matches the operating temperature of a clothes dryer.

[0059] In some embodiments of the present invention, the toughening agent is one or more of maleic anhydride-grafted polyolefin, ethylene-vinyl acetate copolymer (EVA), and ethylene-acrylic acid copolymer (EAA), preferably maleic anhydride-grafted polyolefin (products include, but are not limited to, those with maleic anhydride grafted polyolefin). E588, Bynel 5000, Bynel50E803).

[0060] In some embodiments of the present invention, the polymer substrate is a polyolefin, preferably low-density polyethylene and / or polypropylene.

[0061] In some embodiments of the present invention, the molecular weight of the polymer substrate is 100,000 to 1,000,000; for example, it can be 100,000, 150,000, 200,000, 250,000, 300,000, 400,000, 500,000, 600,000, 700,000, 800,000, 900,000 or 1,000,000.

[0062] In some embodiments of the present invention, the temperature-sensitive material further includes a thermally conductive material.

[0063] In some embodiments of the present invention, the thermally conductive material comprises 3-6% by mass in the temperature-sensitive material; for example, it can be 3%, 3.2%, 3.5%, 3.8%, 4%, 4.2%, 4.5%, 4.8%, 5%, 5.2%, 5.5%, 5.8%, or 6%, etc. The thermally conductive material can improve the thermal conductivity of the temperature-sensitive material, allowing the temperature of the material to reach equilibrium with the ambient temperature more quickly, thereby improving the response speed of the temperature-sensitive material's air permeability to temperature changes. If the content of the thermally conductive material is too low, the response speed of the temperature-sensitive material will be low; if the content of the thermally conductive material is too high, the thermal conductivity of the temperature-sensitive material will not be further improved, and it will also affect the proportion of effective components such as composite phase change materials, thus affecting the temperature-sensitive performance of the material.

[0064] In some embodiments of the present invention, the thermally conductive material includes thermally conductive ceramic materials and / or aminated thermally conductive ceramic materials.

[0065] In some embodiments of the present invention, the particle size of the thermally conductive material is 1-10 μm; for example, it can be 1 μm, 2 μm, 3 μm, 5 μm, 6 μm, 8 μm or 10 μm, etc.

[0066] In some embodiments of the present invention, the thermally conductive ceramic material includes one or more of hexagonal boron nitride (BN), silicon nitride (Si3N4), aluminum oxide (Al2O3), aluminum nitride (AlN), and silicon carbide (SiC).

[0067] In some embodiments of the present invention, the thermally conductive material is aminated hexagonal boron nitride.

[0068] Aminated thermally conductive ceramic materials exhibit higher thermal conductivity than corresponding ordinary thermally conductive ceramic materials. In this embodiment of the invention, the method of amination modification is not specifically limited; as a non-limiting example, the method of amination modification includes the following steps:

[0069] (a) The thermally conductive ceramic material powder is mixed and ground with a strong alkaline solution, and then placed in a polytetrafluoroethylene bottle for reaction. After the reaction is completed, the solid product is separated and dried to obtain the hydroxylated thermally conductive ceramic material.

[0070] (b) The hydroxylated thermally conductive ceramic material is mixed with an ethanolic solution of aminosilane coupling agent and reacted. After the reaction is completed, the solid product is separated, washed, dried and ground to obtain the amino-based thermally conductive ceramic material powder.

[0071] Wherein, the strong alkali can be sodium hydroxide, the mass ratio of thermally conductive ceramic material to strong alkali can be 1:3, and the concentration of strong alkali solution can be 5 mol / L;

[0072] The reaction temperature in step (a) can be 120°C, and the reaction time can be 3 hours.

[0073] The aminosilane coupling agent can be γ-aminopropyltriethoxysilane (KH550) and / or N-aminoethyl-γ-aminopropyltriethoxysilane (KH791);

[0074] The mass ratio of aminosilane coupling agent to thermally conductive ceramic material can be 25:1;

[0075] The ethanol acidic solution of the aminosilane coupling agent can be prepared by the following method: mix the aminosilane coupling agent and ethanol at a volume ratio of 1:3, sonicate for 40 min, stir at room temperature for 90 min, and adjust the pH to 4-5 with hydrochloric acid.

[0076] The reaction conditions in step (b) can be ultrasonic stirring at room temperature for 6 hours.

[0077] In some embodiments of the present invention, the temperature-sensitive material further includes an anti-aging agent and / or a reversible thermochromic material.

[0078] In some embodiments of the present invention, the antioxidant in the temperature-sensitive material has a mass content of 0.3-0.6%; for example, it may be 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6%, etc.

[0079] In some embodiments of the present invention, the antioxidant includes one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), dilauryl thiodipropionate (antioxidant 412s), 2,6-di-tert-butyl-4-methylphenol (antioxidant BHT), butylated hydroxyanisole (antioxidant BHA), and tert-butylhydroquinone (antioxidant TBHQ).

[0080] In some embodiments of the present invention, the reversible thermochromic material has a mass content of 0.1-0.2% in the thermosensitive material; for example, it may be 0.1%, 0.12%, 0.13%, 0.15%, 0.16%, 0.18%, or 0.2%, etc.

[0081] In this embodiment of the invention, a reversible thermochromic material whose color-changing temperature matches the response temperature of the thermosensitive material is added to the thermosensitive material. This allows the color change to visually indicate the occurrence of a phase transition within the thermosensitive material. The reversible thermochromic material has no significant impact on the performance of the thermosensitive material, therefore it can be added or not.

[0082] Secondly, embodiments of the present invention provide a method for preparing a temperature-sensitive material as described in the first aspect, the method comprising the following steps:

[0083] (1) Mix paraffin and C17-C24 alkanes evenly to obtain a composite phase change material;

[0084] (2) Optionally, the composite phase change material and the thermally conductive material are mixed evenly in an organic solvent and dried to obtain a modified phase change material;

[0085] (3) The composite phase change material or the modified phase change material is heated to a liquid state and mixed evenly with a polymer substrate, toughening agent, optional antioxidant and optional reversible thermochromic material. The mixture is then melt-extruded using a screw extruder to obtain the thermosensitive material.

[0086] It should be noted that in the embodiments of the present invention, "optional" means that the corresponding operation can be performed or not performed, and the corresponding raw materials can be added or not added. For example, step (2) above needs to be performed or not performed depending on whether the temperature-sensitive material contains thermally conductive material; the antioxidant and reversible thermochromic material in step (3) need to be added or not added depending on whether the temperature-sensitive material contains the component.

[0087] In some embodiments of the present invention, the mixing temperature in step (1) is 65-80°C; for example, it can be 65°C, 68°C, 70°C, 72°C, 75°C, 78°C or 80°C, etc.

[0088] In some embodiments of the present invention, the organic solvent is carbon tetrachloride.

[0089] In some embodiments of the present invention, the mixing temperature in step (2) is 65-75°C; for example, it can be 65°C, 66°C, 68°C, 70°C, 72°C, 73°C or 75°C, etc.

[0090] In some embodiments of the present invention, the screw extruder in step (3) is a twin-screw extruder, the operating temperature range of which is 170-190℃ and the screw speed is 18-30r / min (for example, it can be 18r / min, 20r / min, 22r / min, 23r / min, 25r / min, 26r / min, 28r / min or 30r / min, etc.).

[0091] In some embodiments of the present invention, the preparation method further includes: after the melt extrusion in step (3), cooling, drying and pelletizing the extruded melt.

[0092] Thirdly, embodiments of the present invention provide a temperature-sensitive film, wherein the material of the temperature-sensitive film is the temperature-sensitive material described in the first aspect.

[0093] In this embodiment of the invention, the preparation method of the temperature-sensitive film is not limited, and those skilled in the art can choose conventional methods. As a non-limiting example, temperature-sensitive material particles can be melt-extruded using a single-screw extruder and then cast into a film.

[0094] The operating temperature range of the single-screw extrusion casting machine can be 175-195℃, and the screw speed can be 25-40r / min (e.g., 25r / min, 26r / min, 28r / min, 30r / min, 32r / min, 33r / min, 35r / min, 36r / min, 38r / min or 40r / min, etc.).

[0095] Fourthly, embodiments of the present invention provide an application of the temperature-sensitive material as described in the first aspect or the temperature-sensitive membrane as described in the third aspect in controlled gas release.

[0096] The temperature response characteristics of the thermosensitive material provided in this invention allow it to reduce gas permeation below the response temperature and accelerate gas permeation when the response temperature is reached, thereby achieving the effect of controlling gas release. Therefore, it has promising applications in gas controlled release.

[0097] As an example application, temperature-sensitive materials can be fabricated into temperature-sensitive films, which encapsulate slow-release materials containing volatile functional substances for use in dryers. When the dryer is operating, the temperature-sensitive film heats up to its response temperature under the influence of hot air, increasing its permeability and allowing the volatile functional substances inside to be released rapidly, thus treating the clothes. When the dryer stops operating, the temperature of the temperature-sensitive film drops below the response temperature, reducing its permeability and decreasing the release of volatile functional substances, thereby extending the lifespan of the slow-release material.

[0098] In this embodiment of the invention, the type of sustained-release material containing volatile functional substances is not specifically limited. It can be any material conventionally available in the art capable of sustaining the release of volatile functional substances, such as hydrogel aromatherapy products prepared using gelatin, sodium alginate, carrageenan, etc., as base materials. However, in the high-temperature environment of a clothes dryer, such sustained-release materials are prone to drying out and cracking, leading to unstable evaporation rates and forms. Therefore, for the application scenario of clothes dryers, this embodiment of the invention also provides a high-temperature resistant sustained-release material, the raw materials for which, by mass percentage, are:

[0099]

[0100] The polyether blocks in the polyether-polyamide block copolymer are soft segments, which are amorphous regions with a loosely arranged molecular structure and large, numerous gaps. Volatile functional substances can easily enter the internal pores and bind to the material through physical adsorption such as van der Waals forces and hydrogen bonds. However, the amorphous region is easily affected by temperature, causing internal structural distortion and slippage, leading to the rapid release of adsorbed volatile functional substances. Therefore, hard segments are needed to provide structural support. The polyamide blocks are hard segments, which are crystalline regions with a regular and compact molecular arrangement. Volatile functional substances do not easily enter the structure, and because the hard segment structure is less affected by temperature, the small amount of volatile functional substances that do enter are not easily released. Therefore, soft segments are needed to absorb and release volatile functional substances. The hard and soft segments work together to achieve the slow release of volatile functional substances.

[0101] Furthermore, the mass percentage of polyamide hard segments in the polyether polyamide block copolymer can be 25-65%, preferably 40-50%.

[0102] Furthermore, the polyether block in the polyether-polyamide block copolymer can be polyethylene glycol, polypropylene glycol, or polybutanediol, etc.; the polyamide block can be polycaprolactam, polyamide 66 (polyhexamethylene adipamide), polydodecanoic acid lactam, or aromatic polyamide, etc.

[0103] The curing agent is used to crosslink the polyamide blocks into a three-dimensional network structure. The curing agent may be selected from one or more of isocyanurates, isocyanates, and aziridine crosslinking agents, preferably aliphatic isocyanates.

[0104] The dispersant is used to promote the uniform penetration and dispersion of volatile functional substances in the polyether polyamide block copolymer. The dispersant may be selected from at least one or more of isoamyl acetate, polydimethylsiloxane, C12-15 alkanol benzoate and cetyl alcohol white oil, preferably C12-15 alkanol benzoate.

[0105] The types of volatile functional substances can be rationally selected according to the required functions, such as sterilization, deodorization, anti-oxidation, formaldehyde removal, softening, anti-static, and anti-yellowing. For the application scenario of clothes dryers, the volatile functional substances are preferably oily plant essential oils, which can better integrate with polyether polyamide block copolymers and dispersants. The plant essential oils can be selected from one or more of the following: phytoncides, green tea essential oil, lemon essential oil, rose essential oil, rosemary essential oil, thyme essential oil, artemisia essential oil, and cedarwood essential oil.

[0106] The pigment may be an oil-based pigment.

[0107] This invention also provides a method for preparing the high-temperature resistant slow-release material, comprising the following steps:

[0108] S1. Mix the polyether polyamide block copolymer with the dispersant and stir until the solution becomes transparent;

[0109] S2. Add volatile functional substances and optional pigments, and stir to mix evenly;

[0110] S3. Add curing agent, stir and mix evenly, then let stand to defoam and form a slow-release material precursor;

[0111] S4. Pour the above-mentioned slow-release material precursor into a mold and cure it at room temperature to obtain the high-temperature resistant slow-release material.

[0112] The high-temperature resistant slow-release material provided in this invention will not shrivel or crack when used in the high-temperature environment of a dryer, and can maintain a stable evaporation rate and form.

[0113] Furthermore, this invention has discovered that volatile functional substances often contain natural aromatic compounds, which have irritating odors. Therefore, to address this issue, embodiments of this invention also provide a method for reducing the irritating odor of slow-release materials containing volatile functional substances. The method involves adding an odor-encapsulating and masking agent or a homologous odor competitor to the slow-release material. The odor-encapsulating and masking agent can effectively adsorb and encapsulate various odor molecules, allowing them to evaporate into the atmosphere along with the odor molecules.

[0114] The following are some non-limiting examples of odor-encapsulating barrier agents or homologous odor competitors:

[0115] 1) Odor-encapsulating and shielding agent one, by weight, includes: 1-10 parts of odor-masking herb, 1-10 parts of fragrance, 1-5 parts of ultraviolet absorber and 75-97 parts of free radical adsorbent;

[0116] The fragrance includes one or more of eugenol, limonene, linalool, citral, and citronellol.

[0117] Ultraviolet absorbers include one or more of the following: phenyl salicylate compounds, benzotriazole compounds, and benzophenone compounds;

[0118] Free radical adsorbents include one or more of hydroquinone, p-benzoquinone, methyl hydroquinone, p-hydroxyanisole, and 2-tert-butylhydroquinone;

[0119] The amount of this odor-encapsulating barrier agent added to the slow-release material can be 0.01-3 wt%.

[0120] 2) Odor encapsulation and shielding agent two, including: masking agent and fragrance agent;

[0121] Masking agents include one or more of zinc stearate, isooctanol, and the German GP-OA series of masking agents;

[0122] The flavoring agent is composed of one or more of the following: ethyl butyrate, ethyl acetate, ethyl ethanol, methyl ethyl ester, ethyl benzyl alcohol, etc.

[0123] The amount of this odor-encapsulating barrier agent added to the slow-release material can be 0.05-3 wt%.

[0124] 3) Odor-encapsulating and shielding agent three, mainly composed of natural aromatic compounds;

[0125] The natural aromatic compounds include one or more of the following: eucalyptol, cinnamaldehyde, eugenol, terpineol, limonene, linalool, and β-pinene;

[0126] The amount of this odor-encapsulating barrier agent added to the slow-release material can be 0.05-3 wt%.

[0127] 4) Competitors for the same scent, including one or more of lavender, lemon, and rose essential oils. Based on the differences in scent intensity, select a fragrance with high intensity and rapid volatility to harmonize the scent of the functional essential oil system.

[0128] The amount of this homologous odor competitor added to the sustained-release material can be 3-10 wt%.

[0129] By adding the aforementioned odor-encapsulating and shielding agents or homologous odor competitors to the sustained-release materials, the irritation of the odor of sustained-release materials containing volatile functional substances can be effectively reduced.

[0130] To make the technical problems solved, technical solutions, and beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0131] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with conventional techniques or conditions in the art, techniques or conditions described in the literature, or product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0132] The amino-modified hexagonal boron nitride used in the following examples was prepared using the following method:

[0133] (a) Mix hexagonal boron nitride powder and sodium hydroxide powder at a mass ratio of 1:3, grind them, and then place them in a polytetrafluoroethylene bottle. React at 120°C for 3 hours. After the reaction is complete, separate the solid product and dry it to obtain hydroxylated hexagonal boron nitride.

[0134] (b) The aminosilane coupling agent KH550 was mixed with ethanol at a volume ratio of 1:3, sonicated for 40 min, stirred at room temperature for 90 min, and the pH was adjusted to 4 with hydrochloric acid. Then, the hydroxylated hexagonal boron nitride was added, with a mass ratio of KH550 to hydroxylated hexagonal boron nitride of 25:1. The mixture was sonicated and stirred at room temperature for 6 h. After the reaction was completed, the solid product was separated, washed, dried, and ground to obtain aminolated hexagonal boron nitride powder. 50 Particle size is 1.5μm. Store in a sealed, light-proof container for later use.

[0135] Example 1

[0136] This embodiment provides a temperature-sensitive film whose material is composed of the following components by mass percentage:

[0137]

[0138] In this embodiment, the method for preparing the temperature-sensitive film is as follows:

[0139] (1) Paraffin and n-octadecane were stirred and mixed evenly at 70°C and cooled to room temperature to obtain the composite phase change material OD / P;

[0140] (2) The composite phase change material OD / P and aminated hexagonal boron nitride were added to carbon tetrachloride, stirred and mixed evenly at 70°C, and dried at 80°C to obtain the modified phase change material.

[0141] (3) The modified phase change material is heated to a liquid state and mixed evenly with PP particles, toughening agent, antioxidant 1010 and reversible thermochromic material. The mixture is then melt-extruded using a twin-screw extruder. The working temperature range of the twin-screw extruder is 170-190℃ and the screw speed is 24r / min. The extruded melt is cooled, dried and pelletized to obtain thermosensitive material particles.

[0142] (4) The temperature-sensitive material particles are added to the hopper of a single-screw extruder and extruded at high temperature. The working temperature range of the single-screw extruder is 175-195℃ and the screw speed is 35r / min. The extruded melt is cast into a film to obtain the temperature-sensitive film.

[0143] Example 2

[0144] This embodiment provides a temperature-sensitive film, which differs from Embodiment 1 only in its material composition, as detailed below:

[0145]

[0146] Example 3

[0147] This embodiment provides a temperature-sensitive film, which differs from Embodiment 1 only in its material composition, as detailed below:

[0148]

[0149] Example 4

[0150] This embodiment provides a temperature-sensitive film, which differs from Embodiment 1 only in that the temperature-sensitive film does not contain thermally conductive materials.

[0151] Preparation of PP and LDPE membranes:

[0152] Following the methods in steps (3) and (4) of Example 1, PP particles and LDPE particles were respectively prepared into PP films and LDPE films for subsequent testing.

[0153] Performance testing

[0154] 1. Surface morphology characterization

[0155] The surface morphology of the temperature-sensitive film and the ordinary PP film provided in Example 1 were observed using a scanning electron microscope. The results are as follows: Figure 1A and Figure 1B As shown.

[0156] from Figure 1A and Figure 1B It can be seen that the temperature-sensitive membrane provided in Example 1 has two phases: a reversible phase OD / P that changes with temperature and a relatively non-flowing PP phase; while ordinary PP membranes only have a uniform PP phase.

[0157] 2. Infrared spectroscopy characterization

[0158] The infrared spectra of the temperature-sensitive film provided in Example 1, the composite phase change material OD / P prepared in Example 1, and the ordinary PP film were tested using an infrared spectrometer. The results are as follows: Figure 2 As shown.

[0159] from Figure 2 It can be seen that, compared to ordinary PP film, the infrared spectrum of the temperature-sensitive film provided in Example 1 shows that at 1470 cm⁻¹... -1 722cm -1 A distinct absorption peak was generated at this point, which is the vibrational absorption peak generated by the composite phase change material OD / P.

[0160] 3. Thermal conductivity test

[0161] The thermal conductivity of the temperature-sensitive materials prepared in Examples 1 and 4 was tested using a TC3000E thermal conductivity meter. Acquisition phase: liquid phase; acquisition time: 1 s; acquisition mode: rapid acquisition; test voltage: 1.5 V; time interval: 3 min.

[0162] The thermal conductivity of the temperature-sensitive material prepared in Example 1 was 0.2213 W / m·K, and the thermal conductivity of the temperature-sensitive material prepared in Example 4 was 0.1702 W / m·K. It is evident that adding 3 wt% thermally conductive material can significantly improve the thermal conductivity of the temperature-sensitive material, thereby helping to improve its response speed.

[0163] 4. Differential scanning calorimetry test

[0164] The temperature-sensitive membrane provided in the example was tested using a differential scanning calorimeter at a heating rate of 5°C / min, and the differential scanning curve was obtained.

[0165] The differential scanning spectral curve of the temperature-sensitive film provided in Example 1 is as follows: Figure 3 As shown. From Figure 3It can be seen that the crystallization melting temperature (i.e., phase transition temperature) of the temperature-sensitive film is 49.55℃.

[0166] The phase transition temperatures of the temperature-sensitive films provided in Examples 2 and 3 were measured to be 62.4°C and 43.7°C, respectively, using the same method. These phase transition temperatures match the operating temperature range of the dryer.

[0167] 5. Breathability test

[0168] The prepared temperature-sensitive membrane was tested using a VAC-V2 air permeability tester, with oxygen as the test gas. The oxygen permeability coefficient was calculated using the following formula:

[0169]

[0170] In the formula, O p Oxygen permeability coefficient (cm) 3 ·cm / cm 2 ·s·Pa); d is the sample thickness (cm); Δp / Δt is the arithmetic mean of the change in low-pressure chamber pressure per unit time during stable transmission (Pa). -1 ·h); T is the sample temperature (K); T0 is the temperature under standard conditions (K); S is the sample area (cm²). 2 P0 is standard atmospheric pressure (Pa); p1-p2 is the pressure difference across the sample (Pa); V is the volume of the low-pressure chamber (cm³). 3 ).

[0171] The air permeability-temperature curve of the temperature-sensitive membrane provided in Example 1 is as follows: Figure 4 As shown in Table 1, the oxygen permeability coefficient data of the temperature-sensitive membranes provided in Examples 1-3 are shown in Table 1.

[0172] Table 1

[0173]

[0174] from Figure 4 As can be seen from the data in Table 1, the oxygen permeability coefficients of PP film and LDPE film are similar at 25℃ and 55℃, showing no temperature response. However, the oxygen permeability coefficient of the temperature-sensitive films provided in Examples 1-3 increases with increasing temperature, and the oxygen permeability coefficient at the phase transition temperature is approximately an order of magnitude higher than that at 25℃; and from... Figure 4 It can be seen that when the temperature reaches near the phase transition temperature, the rate of increase in the oxygen permeability coefficient is significantly greater compared to other temperature ranges. This indicates that the air permeability of the temperature-sensitive membrane provided in this embodiment of the invention is temperature-responsive.

[0175] 6. Release rate test

[0176] EVA particles (number average molecular weight 2000) and rosemary essential oil were mixed at a mass ratio of 3:1 and stirred until fully absorbed to obtain a sustained-release material. 15g of this sustained-release material was wrapped in a temperature-sensitive membrane, PP membrane, LDPE membrane, or conventional non-woven fabric as provided in the examples. The membrane thickness was 105μm, and the membrane area was 70mm×70mm. The material was then stored in ovens at different temperatures. The weight was measured periodically (accurate to 0.1mg), and the essential oil evaporation rate was calculated using the loss-in-weight method. The results are shown in Table 2.

[0177] Table 2

[0178] Group Release rate at 25℃ (mg / h) Release rate at 55℃ (mg / h) Example 1 3.7 168 Example 2 3.4 40 Example 3 5.2 172 PP film 2.4 11.3 LDPE film 4.3 15.6 Conventional nonwoven fabric 47.2 163

[0179] As can be seen from Table 2, the release rate of essential oils by the temperature-sensitive film provided in the embodiments of the present invention at 25°C is similar to that of PP film and LDPE film, and much lower than that of non-woven fabric packaging commonly used in dryer aromatherapy modules. This obviously helps to reduce the volatilization of essential oils at room temperature and extend the service life of the slow-release material. At a high temperature of 55°C, the release rate of essential oils by the temperature-sensitive films provided in Examples 1 and 3 is significantly increased (the release rate of essential oils by the temperature-sensitive film provided in Example 2 is relatively small because the test temperature of 55°C did not reach the phase transition temperature). This is similar to that of non-woven fabric packaging, which helps to quickly release the internal essential oils when the dryer is working, thus achieving the treatment of clothes.

[0180] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A temperature-sensitive material, characterized in that, The temperature-sensitive material comprises the following components by mass percentage: Composite phase change materials: 13-23%; Toughening agent 1-2%; Polymer substrate allowance; The composite phase change material includes paraffin and C17-C24 alkanes.

2. The temperature-sensitive material according to claim 1, characterized in that, The composite phase change material is composed of 60-90 wt% paraffin and 10-40 wt% C17-C24 alkanes; Preferably, the C17-C24 alkane is n-octadecane.

3. The temperature-sensitive material according to claim 1 or 2, characterized in that, The toughening agent is one or more of maleic anhydride-grafted polyolefin, ethylene-vinyl acetate copolymer, and ethylene-acrylic acid copolymer, preferably maleic anhydride-grafted polyolefin.

4. The temperature-sensitive material according to any one of claims 1-3, characterized in that, The polymer substrate is a polyolefin, preferably low-density polyethylene and / or polypropylene; Preferably, the molecular weight of the polymer substrate is 100,000 to 1,000,000.

5. The temperature-sensitive material according to claims 1-4, characterized in that, The temperature-sensitive material also includes a thermally conductive material; Preferably, the thermally conductive material comprises 3-6% by mass in the temperature-sensitive material; Preferably, the particle size of the thermally conductive material is 1-10 μm; Preferably, the thermally conductive material includes thermally conductive ceramic materials and / or aminated thermally conductive ceramic materials; Preferably, the thermally conductive ceramic material includes one or more of hexagonal boron nitride, silicon nitride, alumina, aluminum nitride, and silicon carbide; Preferably, the thermally conductive material is aminated hexagonal boron nitride.

6. The temperature-sensitive material according to any one of claims 1-5, characterized in that, The temperature-sensitive material also includes an antioxidant and / or a reversible thermochromic material; Preferably, the antioxidant in the temperature-sensitive material has a mass content of 0.3-0.6%; Preferably, the antioxidant comprises one or more of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], dilauryl thiodipropionate, 2,6-di-tert-butyl-4-methylphenol, butyl hydroxyanisole, and tert-butylhydroquinone. Preferably, the reversible thermochromic material comprises 0.1-0.2% by mass in the thermosensitive material.

7. A method for preparing a temperature-sensitive material as described in any one of claims 1-6, characterized in that, The preparation method includes the following steps: (1) Mix paraffin and C17-C24 alkanes evenly to obtain a composite phase change material; (2) Optionally, the composite phase change material and the thermally conductive material are mixed evenly in an organic solvent and dried to obtain a modified phase change material; (3) The composite phase change material or the modified phase change material is heated to a liquid state and mixed evenly with a polymer substrate, toughening agent, optional antioxidant and optional reversible thermochromic material. The mixture is then melt-extruded using a screw extruder to obtain the thermosensitive material.

8. The preparation method according to claim 7, characterized in that, The mixing temperature in step (1) is 65-80℃; Preferably, the organic solvent is carbon tetrachloride; Preferably, the mixing temperature in step (2) is 65-75°C; Preferably, the screw extruder in step (3) is a twin-screw extruder, and the working temperature range of the twin-screw extruder is 170-190℃, and the screw speed is 18-30r / min.

9. A temperature-sensitive film, characterized in that, The material of the temperature-sensitive film is the temperature-sensitive material as described in any one of claims 1-6.

10. The application of the temperature-sensitive material as described in any one of claims 1-6 or the temperature-sensitive membrane as described in claim 9 in controlled gas release.

Images