Hydrophobic base functional substance sustained-release material and preparation method thereof

Abstract

The application provides a hydrophobic base functional substance slow-release material and a preparation method thereof, and belongs to the technical field of high polymer composite slow-release materials. The material forms a hydrophobic phase by using a hydrophobic base material, forms a functional release component by using scale inhibition functional substances and / or bacteriostatic functional substances and a swellable material, and introduces a composite skeleton stable component obtained by water phase compounding of part of the swellable material and an inorganic skeleton material; during preparation, the composite skeleton stable component is first dispersed in the hydrophobic base material, then the functional release component is added, and a suitable device is used to process into a required form; the swellable material forms a water migration area, the inorganic skeleton material helps to limit the excessive expansion of a hydrophilic area, the hydrophobic phase adjusts the water entry and the functional substance migration, so that the sustained release of scale inhibition and / or bacteriostatic functions and the structural stability after long-term immersion are considered.

Description

Technical Field

[0001] This invention belongs to the field of polymer composite sustained-release materials technology, and relates to a hydrophobic functional substance sustained-release material and its preparation method. Background Technology

[0002] Hydrophobic functional slow-release materials typically disperse scale inhibitors, antibacterial agents, and other functional substances within a hydrophobic polymer matrix, and incorporate swellable materials to create migration channels for water and functional substances, thereby extending the effective time of the functional substances. Depending on the installation structure and usage method, slow-release materials can also be processed into spherical, granular, or block products.

[0003] When materials are soaked for a long time, repeatedly changed with water, or continuously flowed through, the functional substances gradually dissolve and form pores in the original occupied area; repeated water absorption and contraction of swellable materials may also cause adjacent pores to connect and migration channels to expand, resulting in rapid release in the early stage and insufficient effective substances in the later stage, and causing the material to increase in volume, crack or loosen in structure.

[0004] Existing technologies typically suppress release by adding hydrophobic substrates or promote release by adding swellable materials. However, the former may result in insufficient effective release, while the latter may accelerate migration channel connectivity and structural damage. When ordinary inorganic fillers are directly mixed with the components, their distribution is somewhat random and may not provide sustained support near hydrophilic regions where voids are easily formed. Simply increasing the amount of filler may also block the migration channels of functional substances. Furthermore, scale-inhibiting and antibacterial functional substances differ in molecular weight, solubility, and dosage, and the addition of optional processing aids may also alter the distribution of phases within the material.

[0005] Therefore, the technical problem that the existing technology urgently needs to solve is: how to slow down the excessive expansion and interconnection of the hydrophilic migration region after the continuous dissolution of functional substances without significantly inhibiting the effective release of functional substances, while taking into account the ability to maintain the release in the later stage, the long-term scale inhibition or antibacterial effect and the structural stability after immersion in water, and improving the adaptability of the slow-release material to different functional substances and product forms. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a hydrophobic functional substance slow-release material and its preparation method, thereby solving the problem that existing slow-release materials cannot simultaneously achieve continuous release of functional substances and material structural stability during long-term immersion, repeated water changes, or continuous flow. Furthermore, the invention enables the same material system to carry scale-inhibiting functional substances, antibacterial functional substances, or a combination of both, as needed.

[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a hydrophobic functional substance sustained-release material, comprising a hydrophobic substrate, a functional release component, and a composite framework stabilizing component.

[0008] The hydrophobic substrate forms or participates in the formation of a hydrophobic phase.

[0009] The functional release component includes functional substances and swellable materials, wherein the functional substances include scale inhibitory functional substances and / or antibacterial functional substances.

[0010] The composite framework stabilizing component is prepared by aqueous phase composite treatment of some swellable materials and inorganic framework materials.

[0011] The functional release component and the composite framework stabilizing component are respectively dispersed in the hydrophobic phase.

[0012] Preferably, the scale-inhibiting functional substance is one or more of polyacrylic acid and its salts, polyepoxysuccinic acid and its salts, organophosphonic acid and its salts, 2-phosphonobutane-1,2,4-tricarboxylic acid, hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and citric acid.

[0013] Preferably, the antibacterial functional substance is one or more of isothiazolinone antibacterial agents, guanidine antibacterial agents, benzalkonium chloride, and propylparaben.

[0014] Preferably, the isothiazolinone antibacterial agent is one or more of 1,2-benzisothiazolin-3-one (BIT), 2-methyl-4-isothiazolin-3-one (MIT), 2-n-octyl-4-isothiazolin-3-one (OIT), and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT).

[0015] Preferably, the guanidine antibacterial agent is one or more of polyhexamethylene monoguanidine and its salts, polyhexamethylene biguanidine and its salts, and polyhexamethylene phosphate guanidine.

[0016] This invention uses scale-inhibiting and antibacterial functional substances as the main functional materials. Without affecting the synergistic relationship between the hydrophobic phase, functional release components, and composite framework stabilizing components, other functional substances can be added according to actual needs to meet specific application scenarios.

[0017] Preferably, the hydrophobic substrate is one or both of polyvinyl acetate and polycaprolactone.

[0018] Preferably, the swelling material is one or more of hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose, and methyl cellulose.

[0019] Preferably, the inorganic framework material is two of silicon dioxide, titanium dioxide, zinc oxide, zinc carbonate, and calcium phosphate, and at least one of them is silicon dioxide, titanium dioxide, or calcium phosphate; when the functional substance is polyacrylic acid or polyacrylate, the two inorganic framework materials are one of silicon dioxide, titanium dioxide, and calcium phosphate, and one of zinc oxide and zinc carbonate.

[0020] Preferably, the composite skeleton stabilizing component is prepared by dispersing a portion of the swellable material in water and then performing an aqueous phase composite treatment with the inorganic skeleton material, followed by drying, pulverizing, and sieving.

[0021] Preferably, the particle size of the composite framework stabilizing component is 50-300 μm.

[0022] Preferably, based on 100 parts by weight of the hydrophobic substrate, the swelling material comprises 5-20 parts by weight, and the inorganic framework material comprises 20-60 parts by weight; when the scale-inhibiting functional substance is present, the scale-inhibiting functional substance comprises 20-100 parts by weight; when the antibacterial functional substance is present, the antibacterial functional substance comprises 0.1-20 parts by weight.

[0023] In one alternative embodiment, the hydrophobic functional substance slow-release material further includes one or more of a plastic material, an adhesive, and a pigment. These components are used to improve processing adaptability or impart visual identification features without altering the status of the scale-inhibiting and / or antibacterial functional substances as the primary functional substances.

[0024] Preferably, the plasticizing material is one or more of thermoplastic polyurethane elastomer (TPU), thermoplastic elastomer (TPE), thermoplastic vulcanizate (TPV), ethylene-vinyl acetate copolymer (EVA), polyethylene (PE), and polypropylene (PP). The plasticizing material can be selected and added according to the processing performance and usage requirements of the material.

[0025] Preferably, the adhesive is one or more selected from styrene-acrylic emulsion, acrylic resin, phenolic resin, and polyvinyl butyral. The adhesive can be selected and added according to the component bonding state of the material and processing requirements; when the adhesive is an emulsion, its amount is based on effective solid mass.

[0026] Preferably, the pigment is an organic or inorganic pigment that is compatible with the hydrophobic substrate, functional substances, and intended use environment, and is used to distinguish product functions or specifications.

[0027] Preferably, based on 100 parts by weight of the hydrophobic substrate, when it contains plastic material, the plastic material is 20-180 parts by weight; when it contains adhesive, the adhesive is 5-30 parts by weight based on effective solids; and when it contains pigment, the pigment is 0.01-1 parts by weight.

[0028] Secondly, the present invention provides a method for preparing the hydrophobic functional substance sustained-release material, comprising the following steps: S1: Disperse some swellable materials in water, add inorganic framework materials for composite treatment, and obtain a composite framework stable component after drying, crushing and sieving; S2: The functional material and the remaining swellable material are dried or dehydrated separately and then mixed to obtain the functional release component; S3: The hydrophobic substrate is dried or dehydrated, and one or more of the following are added or not added as needed for processing: plastic materials, adhesives and pigments, to obtain a hydrophobic matrix; S4: First, add a composite framework stabilizing component to the hydrophobic matrix for dispersion, then add a functional release component for mixing, and use suitable equipment to process the resulting mixture into the desired form to obtain a hydrophobic functional substance slow-release material.

[0029] Preferably, in S1, a portion of the swellable material is dispersed in water to form a dispersion with a solid content of 2-8 wt%. After adding the inorganic framework material, the mixture is stirred at 20-50°C for 20-60 min, and then dried at 50-90°C until the moisture content is not higher than 1 wt%. The mixture is then pulverized and sieved to obtain a composite framework stable component with a particle size of 50-300 μm.

[0030] Preferably, in S1, the swellable material used to prepare the composite framework stabilizing component accounts for 30-70% of the total mass of the swellable material, and the remaining swellable material is used to prepare the functional release component.

[0031] Preferably, in S2, vacuum drying, low-temperature drying, or carrier adsorption dehydration is selected according to the physical state and thermal stability of the functional substance, so that the functional substance and the remaining swellable material are in a uniformly dispersed state before mixing; when the scale inhibitor and antibacterial functional substances are used at the same time, they are pretreated separately before being mixed with the remaining swellable material.

[0032] Preferably, in S3, one or more of the following can be added: a plastic material, an adhesive, and a pigment, depending on the material's processing performance, component bonding state, and appearance identification requirements.

[0033] This invention does not simply utilize a hydrophobic substrate for conventional coating of functional substances, nor does it directly add inorganic framework materials as ordinary fillers. Instead, it distributes the swellable material into two types of components with different functions: one part of the swellable material combines with the inorganic framework material in an aqueous phase to form a composite framework stabilizing component, and the other part of the swellable material combines with scale-inhibiting and / or antibacterial functional substances to form a functional release component. The two types of components are then dispersed separately in a hydrophobic phase. Thus, the swellable material simultaneously undertakes the dual functions of "establishing functional substance migration regions" and "assisting the inorganic framework material in stabilizing hydrophilic regions," forming interconnected but distinct micro-region structures.

[0034] In preparing the composite framework stabilizer, some of the swellable material is first fully hydrated and expanded in an aqueous phase. Its molecular chains can then distribute on the surface and between the inorganic particles through hydrogen bonding, van der Waals interactions, surface adsorption, and segment bridging. After drying, the inorganic particles no longer exist primarily as independent powders, but rather form composite particles or composite micro-regions with the swellable material. Compared to directly mixing the swellable material and the inorganic framework material after separate drying, this aqueous pre-composite process helps reduce the aggregation of inorganic particles and pre-establishes a more stable adjacent distribution between the inorganic framework material and the hydrophilic polymer.

[0035] When carboxymethyl cellulose is selected as the swelling material, or when the system also contains polyacrylic acid-based scale inhibitors, the zinc sites on the surface of zinc oxide or zinc carbonate may also undergo partial ionic or coordination interactions with carboxyl groups, thereby helping to enhance the interfacial bonding between the organic hydrophilic components and inorganic particles. This effect does not require the formation of a fully cross-linked structure, and therefore does not fix all functional substances in a non-release state, but mainly manifests as improving the dispersion stability of the inorganic framework material near the hydrophilic microregion. For silica, titanium dioxide, or calcium phosphate, local support can be formed through surface adsorption, hydrogen bonding, and solid particle occupancy. Therefore, the embodiments of this invention verify the combined use of two inorganic framework materials in corresponding formulation systems after aqueous phase composite, rather than the achievement of the same technical effect by adding any one of the listed inorganic framework materials alone; different inorganic framework materials cannot be equivalently replaced solely based on their poorly soluble particle properties or total dosage, and the above-mentioned structural stabilization effect is not determined by a single chemical reaction.

[0036] The swellable material in the functional release component absorbs water upon contact with the material, forming hydrophilic migration regions that allow scale-inhibiting and / or antibacterial functional substances to dissolve, diffuse, and be gradually released. The composite framework stabilizing component also contains swellable materials, thus exhibiting similar hydrophilic compatibility to the functional release component. This facilitates the formation of adjacent or staggered microregions within the hydrophobic continuous phase, rather than allowing the inorganic framework material to be randomly dispersed in locations unrelated to the release pathway. As the functional substances gradually dissolve, the sparingly soluble inorganic particles in the composite framework stabilizing component retain local solid sites, while the surrounding swellable material helps maintain the bond between the inorganic particles and the hydrophilic regions, thereby mitigating the tendency for the functional substance-occupied areas to directly evolve into continuous macropores.

[0037] The hydrophobic phase separates and encapsulates the functional release component and the composite framework stabilizing component to limit the single-entry of moisture into the material. The functional release component is responsible for forming the necessary moisture migration pathways, while the composite framework stabilizing component constrains the excessive expansion of hydrophilic migration regions and the overly rapid connection of adjacent channels. This synergy does not reduce release by simply increasing the amount of hydrophobic substrate, nor by adding large amounts of inorganic fillers to block channels. Instead, it utilizes the spatial coupling of two types of hydrophilic microregions in the hydrophobic phase to ensure that the release of functional substances and the structure of the release channels occur simultaneously.

[0038] In the preparation process, the stabilizing component of the composite framework is first added to the hydrophobic matrix to ensure relatively sufficient dispersion before the functional material is added, followed by the addition of the functional releasing component. On one hand, this sequence helps avoid the formation of multi-component agglomerates after all functional materials, swellable materials, and inorganic framework materials are premixed, reducing the possibility of excessive differences in the content of functional materials and inorganic framework materials in different regions. On the other hand, it shortens the time that functional materials are subjected to shear or thermal effects during subsequent mixing, reducing the risk of loss of components sensitive to processing conditions, such as antibacterial functional materials. If the two types of components are pre-dry mixed and added all at once, the functional materials and swellable materials are more likely to preferentially form hydrophilic agglomerates, and the inorganic framework material also finds it difficult to establish a relatively uniform local support distribution beforehand.

[0039] For scale-inhibiting substances, this invention primarily maintains continuous release in the later stages, allowing polyacrylic acid compounds, polyepoxysuccinic acid compounds, organophosphonic acids, or citric acid compounds to continue entering the water body and exert their scale-inhibiting effect after continuous flow. For antibacterial substances, isothiazolinones, guanidines, benzalkonium chloride, or propylparaben are gradually released through the same water migration region. Since release regulation is mainly achieved by the spatial structure of the hydrophobic continuous phase, swellable materials, and composite framework stabilizing components, it does not require different functional substances to participate in the same chemical reaction. Therefore, it can accommodate differences in structure and solubility between scale-inhibiting substances, antibacterial substances, and combinations thereof.

[0040] Plastic materials, adhesives, and pigments are all optional components, which can be added according to the material's processing performance, component binding state, and appearance identification requirements. These components primarily affect the material's processing adaptability or appearance identification characteristics. The core of the continuous release and structure maintenance of this invention remains the combination of the hydrophobic phase, the functional release component, and the composite framework stabilizing component. Without altering the core micro-region structure, products of different shapes can be processed using appropriate equipment to adapt to different installation and overcurrent application scenarios.

[0041] In summary, this invention does not follow the one-way adjustment method of "increasing the amount of hydrophobic substrate to enhance stability" or "increasing the amount of swellable material to promote release". Instead, it allocates the swellable material into a release channel construction part and an inorganic framework composite part, so that the same hydrophilic material serves the migration of functional substances and the maintenance of channel structure respectively. Through aqueous pre-composite and stepwise addition, the two types of micro-regions are coupled to each other in the hydrophobic continuous phase, thereby alleviating the mutual constraint between continuous release and long-term structural stability.

[0042] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention combines a portion of swellable materials with inorganic framework materials in an aqueous phase to form a composite framework stabilizing component, and disperses it and the functional release component separately in a hydrophobic phase. This helps to slow down the excessive expansion of the hydrophilic migration area and the rapid connection of adjacent channels after the functional substances are dissolved, so that the scale inhibition rate and / or antibacterial rate remain at a high level during continuous water exchange, extend the simulated service life under the test conditions of this application, and improve the material integrity and immersion water state during long-term immersion.

[0043] This invention, through the coordination of hydrophobic phase, functional release component and composite framework stabilizing component, enables the functional substance migration region and structure maintenance region to cooperate with each other without relying on the participation of functional substances in chemical cross-linking. This alleviates the contradiction between improving the functional substance release capacity and maintaining the material structure stability, thereby taking into account the scale inhibition or antibacterial effect under repeated water change conditions and qualified soaking performance.

[0044] The present invention adopts a preparation sequence of first dispersing the composite framework stabilizing component in a hydrophobic matrix and then adding the functional release component. This helps to reduce local agglomeration and uneven distribution that occur when all functional substances, swellable materials and inorganic framework materials are premixed, and shortens the time that functional substances are subjected to mechanical shear or thermal effects during subsequent mixing, thereby further improving the late-stage release retention capacity and long-term structural stability of the sustained-release material.

[0045] The slow-release regulation of this invention is mainly achieved by the micro-regional coordination of hydrophobic phase, swellable material and composite framework stabilizing component. It does not require different functional substances to have the same reactive groups. Therefore, it can be applied to scale inhibitory functional substances, antibacterial functional substances or combinations of the two. Furthermore, while maintaining the above-mentioned slow-release structure, it can be processed into different forms of products according to actual needs using appropriate equipment, thereby improving the adaptability of slow-release materials to different functional requirements and application scenarios. Attached Figure Description

[0046] Figure 1 This is a flowchart of the preparation method of the hydrophobic functional substance sustained-release material described in this application. Detailed Implementation

[0047] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include any obvious substitutions and modifications made to the embodiments described herein.

[0048] All chemical reagents used in the embodiments and comparative examples of this invention are commercially available products. Specifically, the silica is precipitated silica, and the average particle size of zinc oxide, zinc carbonate, titanium dioxide, and calcium phosphate is 0.1-5 μm; BIT, OIT, and polyhexamethylene guanidine phosphate are all solid active ingredients; polyvinyl acetate, polycaprolactone, TPU, and EVA are all processable grade products.

[0049] All parts mentioned in the embodiments and comparative examples of this invention are parts by mass.

[0050] Example 1 This embodiment provides a hydrophobic functional substance slow-release material, which is processed into pure scale-inhibiting slow-release balls. The pure scale-inhibiting slow-release balls include 100 parts of polyvinyl acetate, 60 parts of sodium polyacrylate, 8 parts of hydroxyethyl cellulose, 25 parts of silica, 10 parts of zinc oxide, 15 parts of styrene-acrylic emulsion, and 0.05 parts of pigment, wherein the amount of styrene-acrylic emulsion is based on the effective solid mass.

[0051] The preparation method of the pure scale-inhibiting slow-release balls includes the following steps: S1: Take 50% of the total mass of hydroxyethyl cellulose and add it to deionized water to prepare a dispersion with a solid content of 5 wt%; add silica and zinc oxide to the dispersion and stir at 35°C for 40 min; vacuum dry the resulting mixture at 70°C for 8 h until the water content is not higher than 1 wt%, and after crushing and sieving, obtain a composite framework stabilizing component with a particle size of 150 μm.

[0052] S2: Sodium polyacrylate and the remaining hydroxyethyl cellulose were vacuum dried at 60°C for 4 hours, and then mixed at 400 rpm for 8 minutes to obtain the functional release component.

[0053] S3: Dry polyvinyl acetate at 55°C for 3 hours, mix the dried polyvinyl acetate with the pigment, add styrene-acrylic emulsion, and stir at 25°C for 10 minutes to obtain a hydrophobic matrix.

[0054] S4: First, add the composite framework stabilizing component to the hydrophobic matrix and mix for 8 minutes. Then, add the functional release component and continue mixing for 5 minutes. Use suitable equipment to process the resulting mixture into the desired spherical or near-spherical shape, and then dry it at 60°C for 6 hours to obtain pure scale inhibitory slow-release balls.

[0055] Example 2 This embodiment provides a hydrophobic functional substance sustained-release material, which is processed into pure antibacterial sustained-release spheres. The pure antibacterial sustained-release spheres include 100 parts of polycaprolactone, 2.0 parts of BIT, 8 parts of hydroxypropyl methylcellulose, 20 parts of titanium dioxide, 10 parts of zinc carbonate, and 12 parts of polyvinyl butyral.

[0056] The preparation method of the pure antibacterial sustained-release spheres includes the following steps: S1: Take 62.5% of the total mass of hydroxypropyl methylcellulose and add it to deionized water to prepare a dispersion with a solid content of 2wt%; add titanium dioxide and zinc carbonate to the dispersion and stir at 45°C for 30 min; vacuum dry the resulting mixture at 90°C for 6 h until the water content is not higher than 1wt%, and after crushing and sieving, obtain a composite skeleton stabilizing component with a particle size of 50μm.

[0057] S2: The remaining hydroxypropyl methylcellulose was vacuum dried at 65°C for 4 hours, and BIT was vacuum dried at 45°C for 2 hours. The two were then mixed at 500 rpm for 10 minutes to obtain the functional release component.

[0058] S3: Polycaprolactone and polyvinyl butyral were dried at 60°C for 4 hours, and then mixed at 105°C for 5 minutes to obtain a hydrophobic matrix.

[0059] S4: Keep the hydrophobic matrix temperature at 105℃, first add the composite framework stabilizing component, mix for 4 min, then add the functional release component, and continue mixing for 2 min; use appropriate equipment to process the resulting mixture into the required spherical or near-spherical shape, and after cooling, dry at 55℃ for 4 h to obtain pure antibacterial sustained-release spheres.

[0060] Example 3 This embodiment provides a hydrophobic functional substance slow-release material, which is processed into a slow-release ball with both scale inhibition and antibacterial functions. The slow-release ball with both scale inhibition and antibacterial functions includes 80 parts of polyvinyl acetate, 20 parts of polycaprolactone, 35 parts of sodium hydroxyethylidene diphosphonate, 1.5 parts of BIT, 10 parts of hydroxyethyl cellulose, 25 parts of silica, 12 parts of zinc oxide, and 10 parts of phenolic resin.

[0061] The preparation method of the slow-release ball with both scale inhibition and antibacterial functions includes the following steps: S1: Take 30% of the total mass of hydroxyethyl cellulose and add it to deionized water to prepare a dispersion with a solid content of 8 wt%; add silica and zinc oxide to the dispersion and stir at 50°C for 55 min; vacuum dry the resulting mixture at 60°C for 10 h until the water content is not higher than 1 wt%, and after crushing and sieving, obtain a composite framework stabilizing component with a particle size of 300 μm.

[0062] S2: Sodium hydroxyethylidene diphosphonate and the remaining hydroxyethyl cellulose were vacuum dried at 65°C for 5 hours, and BIT was vacuum dried at 45°C for 2 hours. The three were then mixed at 650 rpm for 6 minutes to obtain the functional release component.

[0063] S3: Polyvinyl acetate, polycaprolactone and phenolic resin were dried at 60°C for 4 hours, and then mixed at 85°C for 6 minutes to obtain a hydrophobic matrix.

[0064] S4: Keep the hydrophobic matrix temperature at 85℃, first add the composite framework stabilizing component, mix for 6 min, then add the functional release component, and continue mixing for 2 min; use appropriate equipment to process the resulting mixture into the required spherical or near-spherical shape, and then dry at 55℃ for 5 h to obtain slow-release spheres with both scale inhibition and antibacterial functions.

[0065] Example 4 This embodiment provides a hydrophobic functional substance sustained-release material, which is processed into pure antibacterial sustained-release particles. The pure antibacterial sustained-release particles include 100 parts of polyvinyl acetate, 1.5 parts of OIT, 8 parts of methylcellulose, 20 parts of titanium dioxide, 15 parts of calcium phosphate, and 80 parts of EVA.

[0066] The preparation method of the pure antibacterial sustained-release granules includes the following steps: S1: Take 70% of the total mass of methylcellulose and add it to deionized water to prepare a dispersion with a solid content of 4wt%; add titanium dioxide and calcium phosphate to the dispersion and stir at 20℃ for 60min; vacuum dry the resulting mixture at 80℃ for 7h until the water content is not higher than 1wt%, and after crushing and sieving, obtain a composite skeleton stabilizing component with a particle size of 100μm.

[0067] S2: The remaining methylcellulose was vacuum dried at 55°C for 3 hours, and the OIT was vacuum dehydrated at 35°C for 2 hours. The two were then mixed at 300 rpm for 12 minutes to obtain the functional release component.

[0068] S3: Dry polyvinyl acetate at 60°C for 4 hours, dry EVA at 80°C for 4 hours, and then mix the two at 120°C for 6 minutes to obtain a hydrophobic matrix.

[0069] S4: First, add the composite framework stabilizing component to the hydrophobic matrix and mix at 120°C for 4 min; then, reduce the temperature of the mixture to 90°C, add the functional release component and continue mixing for 1.5 min; use suitable equipment to process the resulting mixture into the desired granular form, and then dry it at 50°C for 3 h to obtain pure antibacterial sustained-release granules.

[0070] Example 5 This embodiment provides a hydrophobic functional substance sustained-release material, which is processed into a pure antibacterial sustained-release block. The pure antibacterial sustained-release block includes 100 parts of polycaprolactone, 10 parts of polyhexamethylene guanidine phosphate, 10 parts of hydroxyethyl cellulose, 20 parts of silica, 10 parts of zinc carbonate, and 120 parts of TPU.

[0071] The preparation method of the pure antibacterial sustained-release block includes the following steps: S1: Take 40% of the total mass of hydroxyethyl cellulose and add it to deionized water to prepare a dispersion with a solid content of 6 wt%; add silica and zinc carbonate to the dispersion and stir at 30°C for 20 min; vacuum dry the resulting mixture at 50°C for 12 h until the water content is not higher than 1 wt%, and after crushing and sieving, obtain a composite framework stabilizing component with a particle size of 220 μm.

[0072] S2: Polyhexamethylene guanidine phosphate and the remaining hydroxyethyl cellulose were vacuum dried at 70°C for 5 h, and then mixed at 450 rpm for 15 min to obtain the functional release component.

[0073] S3: Dry polycaprolactone at 70°C for 4 hours, dry TPU at 90°C for 4 hours, and then mix the two at 150°C for 8 minutes to obtain a hydrophobic matrix.

[0074] S4: Keep the hydrophobic matrix temperature at 150℃, first add the composite framework stabilizing component, mix for 5 min, then add the functional release component, and continue mixing for 1.5 min; use appropriate equipment to process the resulting mixture into the required block shape, and obtain pure antibacterial sustained-release block after cooling.

[0075] Comparative Example 1 This comparative example provides a hydrophobic functional substance sustained-release material and its preparation method. The difference from Example 1 is that instead of performing a composite treatment of 4 parts of hydroxyethyl cellulose, silica and zinc oxide in an aqueous phase, the three are dried separately and then directly physically mixed as the skeleton additives. The other components, dosages, order of addition and product form are the same as in Example 1.

[0076] Comparative Example 2 This comparative example provides a hydrophobic functional substance sustained-release material and its preparation method. The difference from Example 1 is that zinc oxide is not added, and titanium dioxide of equal mass is used instead of zinc oxide; other components, dosages, preparation steps and product forms are the same as in Example 1.

[0077] Comparative Example 3 This comparative example provides a hydrophobic functional substance sustained-release material and its preparation method. The difference from Example 1 is that silicon dioxide is not added, and only 4 parts of hydroxyethyl cellulose and zinc oxide are subjected to aqueous phase composite treatment; other components, dosages, preparation steps and product forms are the same as in Example 1.

[0078] Comparative Example 4 This comparative example provides a hydrophobic functional substance sustained-release material and its preparation method. The difference from Example 1 is that hydroxyethyl cellulose is not added, and silica and zinc oxide are dispersed in the aqueous phase, dried and pulverized as skeleton additives, while sodium polyacrylate is used alone as the functional release component. Other components, dosages, preparation steps and product forms are the same as in Example 1.

[0079] Comparative Example 5 This comparative example provides a hydrophobic functional substance sustained-release material and its preparation method. The difference from Example 1 is that the composition and preparation method of the composite framework stabilizing component and the functional release component are the same as those in Example 1, but the two are pre-dry mixed and then added to the hydrophobic matrix at one time, instead of dispersing the composite framework stabilizing component first and then adding the functional release component. Other components, dosages and product forms are the same as those in Example 1.

[0080] Performance tests are carried out on the hydrophobic group functional substance slow-release materials of the above Examples 1-5 and Comparative Examples 1-5, and the specific process is as follows: 5 g of the slow-release material is placed in a 500 mL glass container, deionized water is added to reach a constant volume of 500 mL, and the mixture is left to stand and soak for 24 h at 25±1°C. Every 24 h is taken as a water change cycle. When changing water, under the condition that the slow-release material is not taken out, rinsed or dried, all the soaking water in the volumetric flask is poured out, and deionized water is added again to reach a constant volume of 500 mL. The soaking water poured out in each water change cycle is used as the water sample to be tested for that cycle, which is used for corresponding scale inhibition rate and / or bacteriostatic rate detection, and the states of the slow-release material and the soaking water are recorded before each water change. 3 parallel samples are set in each group, and the scale inhibition rate and bacteriostatic rate are taken as the arithmetic average of the results of 3 parallel tests.

[0081] For samples containing scale-inhibiting functional substances, the daily collected water samples to be tested are used as sample solutions containing slow-release scale-inhibiting components, and the scale inhibition rate is measured in accordance with "GB / T 16632-2019 Water treatment chemicals—Determination of scale inhibition performance—Calcium carbonate precipitation method"; samples without added scale-inhibiting functional substances are not subjected to scale inhibition rate detection.

[0082] For samples containing bacteriostatic functional substances, the daily collected water samples to be tested are used as bacteriostatic samples, the bacteriostatic rate is determined according to the bacteriostatic effect test method specified in "QB / T 2738-2023 Evaluation method for antibacterial and bacteriostatic effect of daily chemical products", and the test strain adopts the standard strain of Escherichia coli specified in the standard; samples without added bacteriostatic functional substances are not subjected to bacteriostatic rate detection.

[0083] The soaking performance is evaluated by observing the appearance of the slow-release material and the state of the soaking water. During the soaking process, if the slow-release material has no damage or slag falling off, and the soaking water has no obvious turbidity or viscosity, the soaking performance of the water change cycle is judged as qualified; if any of the following conditions occurs: damage, slag falling off, obvious turbidity or viscosity of the soaking water, the soaking performance of the water change cycle is judged as unqualified. For products of different forms, the above judgment standard is adopted, and the initial form or size of the product is not used as the basis for qualification judgment.

[0084] In the present application, a scale inhibition rate of not less than 90% is taken as the judgment condition for having strong scale inhibition effect, and a bacteriostatic rate of not less than 90% is taken as the judgment condition for having strong bacteriostatic effect. The above 90% is a uniformly set evaluation threshold set by the present application for comparing the long-term water change performance of each sample.

[0085] Starting from the first water change cycle, the number of days corresponding to the last consecutive water change cycle in which the sample's scale inhibition rate and / or antibacterial rate are both not less than 90% and its immersion performance is qualified is recorded as the simulated service life of the sample under this test condition. For samples with both scale inhibition and antibacterial functions, the scale inhibition rate, antibacterial rate, and immersion performance should all meet the above requirements; if any one of them fails to meet the requirements for the first time, the number of days corresponding to the previous water change cycle is taken as the simulated service life.

[0086] The test results are shown in Table 1. "-" indicates that the corresponding sample does not contain the functional substance and was not tested accordingly; the scale inhibition rate and antibacterial rate in the table are the test results of the water sample obtained on the simulated service life end date; "First time failing to meet the criteria on the next day" refers to the first time the above judgment conditions are not met in the next water change cycle.

[0087] Table 1 Performance test results of hydrophobic functional material sustained-release materials in Examples 1-5 and Comparative Examples 1-5

[0088] The test results from Example 1 and Comparative Example 1 show that Comparative Example 1 did not perform aqueous phase composite treatment on hydroxyethyl cellulose, silica, and zinc oxide. Instead, it directly mixed them physically after drying them separately. This resulted in a lack of adsorption, coating, or bridging distribution between the inorganic framework material and the swellable material due to aqueous phase dispersion. During long-term, repeated water changes, differences in water absorption and functional substance migration states in different areas were more likely to occur, leading to relatively concentrated release of functional substances in certain areas and a decrease in sustained scale inhibition capacity in the later stages. Simultaneously, unevenly dispersed hydrophilic components were more likely to migrate into the immersion water, causing turbidity. Therefore, the simulated service life was shorter than that of Example 1.

[0089] The test results from Example 1 and Comparative Example 2 show that, although Comparative Example 2 did not add zinc oxide but replaced it with an equal mass of titanium dioxide, the material still contained inorganic framework materials, and silica and titanium dioxide could still participate in local support through surface adsorption and solid particle occupancy. However, in the sodium polyacrylate system, the lack of supplementary interfacial binding pathways provided by zinc oxide surface zinc sites weakened the compatibility between the inorganic framework materials and carboxyl-containing hydrophilic components. During long-term water changes, the material's scale inhibition and retention capacity decreased, and the scale inhibition rate fell below the judgment threshold earlier, thus shortening the simulated service life. The above results indicate that in polyacrylate-containing systems, inorganic framework materials cannot be replaced solely based on total dosage or the properties of poorly soluble particles.

[0090] The test results from Example 1 and Comparative Example 3 show that Comparative Example 3, which did not add silica but only treated hydroxyethyl cellulose and zinc oxide in an aqueous phase, reduced the types and total amount of inorganic framework materials, resulting in a decrease in the solid occupancy and local support capacity of the insoluble inorganic particles in the composite framework stabilizing component. Although its scale inhibition rate remained at a high level at the end of its simulated service life, indicating that the functional substances could still play a scale inhibition role in this water change cycle, the local voids formed after the continuous dissolution of the functional substances lacked sufficient solid occupancy, leading to earlier material damage and flaking, resulting in unsatisfactory immersion performance. Therefore, its simulated service life was significantly lower than that of Example 1. The above results indicate that in the specific system of Example 1, retaining only zinc oxide while significantly reducing the total amount of inorganic framework materials is insufficient to maintain the long-term structural stability of the material.

[0091] The test results from Example 1 and Comparative Example 4 show that Comparative Example 4 did not contain hydroxyethyl cellulose, and therefore lacked a swellable material that could absorb water and form a continuous hydrophilic migration region. Although omitting the swellable material helps reduce the degree of water absorption and swelling, allowing the material to remain basically intact during immersion, the continuity of water entering the material and sodium polyacrylate migrating outward is insufficient. Consequently, the amount of scale-inhibiting functional material that enters the immersion water and exerts its effect drops below the effective level earlier, resulting in a scale inhibition rate falling below 90% earlier and the shortest simulated service life.

[0092] The test results from Example 1 and Comparative Example 5 show that Comparative Example 5, by pre-dry mixing the composite framework stabilizing component and the functional release component before adding them to the hydrophobic matrix, eliminated the step of pre-dispersing the composite framework stabilizing component. When both types of powders are added together, local agglomeration is more likely to occur, resulting in uneven relative contents of functional substances, swellable materials, and inorganic framework materials in different regions; some hydrophilic regions release more quickly in the early stages, while other regions lack sufficient inorganic framework support. After long-term water changes, the migration of local hydrophilic components causes significant turbidity in the soaking water, and the simulated service life is shorter than that of Example 1, which uses a step-by-step addition method.

[0093] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A hydrophobic functional substance sustained-release material, characterized in that, The product comprises a hydrophobic substrate, a functional release component, and a composite framework stabilizing component; the hydrophobic substrate forms or participates in the formation of a hydrophobic phase; the functional release component includes functional substances and swellable materials, the functional substances including scale-inhibiting functional substances and / or antibacterial functional substances; the composite framework stabilizing component is prepared by aqueous phase composite treatment of a portion of the swellable material and inorganic framework material; the functional release component and the composite framework stabilizing component are respectively dispersed in the hydrophobic phase.

2. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, The scale-inhibiting functional substance is one or more of polyacrylic acid and its salts, polyepoxysuccinic acid and its salts, 2-phosphonobutane-1,2,4-tricarboxylic acid, hydroxyethylidene diphosphonic acid, aminotrimethylene phosphonic acid, and citric acid.

3. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, The antibacterial functional substance is one or more of isothiazolinone antibacterial agents, guanidine antibacterial agents, benzalkonium chloride, and propylparaben; the isothiazolinone antibacterial agent is one or more of 1,2-benzisothiazolin-3-one, 2-methyl-4-isothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, and 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one; the guanidine antibacterial agent is one or more of polyhexamethylene monoguanidine and its salts, polyhexamethylene biguanidine and its salts, and polyhexamethylene phosphate guanidine.

4. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, The hydrophobic substrate is one or both of polyvinyl acetate and polycaprolactone; the swelling material is one or more of hydroxyethyl cellulose, carboxymethyl cellulose, hydroxypropyl methyl cellulose and methyl cellulose.

5. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, The inorganic framework material is two of silicon dioxide, titanium dioxide, zinc oxide, zinc carbonate, and calcium phosphate, and at least one of them is silicon dioxide, titanium dioxide, or calcium phosphate; when the functional substance is polyacrylic acid or polyacrylate, the two inorganic framework materials are one of silicon dioxide, titanium dioxide, and calcium phosphate, and one of zinc oxide and zinc carbonate.

6. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, It also includes one or more of the following: a plastic material, an adhesive, and a pigment; the plastic material is one or more of the following: thermoplastic polyurethane elastomer, thermoplastic elastomer, thermoplastic vulcanized rubber, ethylene-vinyl acetate copolymer, polyethylene, and polypropylene; the adhesive is one or more of the following: styrene-acrylic emulsion, acrylic resin, phenolic resin, and polyvinyl butyral.

7. The hydrophobic functional substance sustained-release material according to claim 1, characterized in that, Based on 100 parts by weight of the hydrophobic substrate, the swelling material comprises 5-20 parts by weight, and the inorganic framework material comprises 20-60 parts by weight; when the scale-inhibiting functional substance is present, the scale-inhibiting functional substance comprises 20-100 parts by weight; when the antibacterial functional substance is present, the antibacterial functional substance comprises 0.1-20 parts by weight.

8. The hydrophobic functional substance sustained-release material according to claim 6, characterized in that, Based on 100 parts by weight of the hydrophobic substrate, when it contains plastic material, the plastic material is 20-180 parts by weight; when it contains adhesive, the adhesive is 5-30 parts by weight based on effective solids; when it contains pigment, the pigment is 0.01-1 parts by weight.

9. A method for preparing a hydrophobic functional substance sustained-release material as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Disperse some swellable materials in water, add inorganic framework materials for composite treatment, and obtain a composite framework stable component after drying, crushing and sieving; S2: The functional material and the remaining swellable material are dried or dehydrated separately and then mixed to obtain the functional release component; S3: The hydrophobic substrate is dried or dehydrated, and one or more of the following are added or not added as needed for processing: plastic materials, adhesives and pigments, to obtain a hydrophobic matrix; S4: First, add a composite framework stabilizing component to the hydrophobic matrix for dispersion, then add a functional release component for mixing, and use suitable equipment to process the resulting mixture into the desired form to obtain a hydrophobic functional substance slow-release material.

10. The preparation method according to claim 9, characterized in that, In S1, the portion of the swellable material used to prepare the composite framework stabilizing component accounts for 30-70% of the total mass of the swellable material, and the remaining swellable material is used to prepare the functional release component; the portion of the swellable material is dispersed in water to form a dispersion with a solid content of 2-8 wt%, and after adding the inorganic framework material, it is stirred at 20-50℃ for 20-60 min, and then dried at 50-90℃ until the water content is not higher than 1 wt%, and after pulverization and sieving, a composite framework stabilizing component with a particle size of 50-300 μm is obtained.

11. The preparation method according to claim 9, characterized in that, In S2, when scale inhibitors and antibacterial agents are used simultaneously, they are pretreated separately before being mixed with the remaining swellable material; in S4, the composite framework stabilizing components are dispersed before the functional release components are added.

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