Resin composition containing crushed shell particles, shell resin button and preparation method of shell resin button

Abstract

The invention provides a resin composition containing crushed shell particles, a shell resin button and a preparation method of the shell resin button. The viscosity of the component A containing the epoxy resin is controlled to be 5000 mPas to 20000 mPas (25 DEG C), so that the crushed shell particles can be uniformly distributed, the crushed shell particles with relatively high density are uniformly and stably dispersed and suspended in an epoxy resin system, and the yield of buttons is improved. Experimental results show that by means of the method, the yield of the shell resin buttons can be increased to 90% or above, the raw material utilization rate is good, the prepared shell resin buttons are uniform in shell particle distribution and complete in curing, the button blanks are good in toughness, edge breakage and particle falling are avoided in modeling processing, and the surfaces are smooth and clean.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of button manufacturing, in particular to a resin composition containing shell particles, a shell resin button and a preparation method thereof. BACKGROUND

[0002] As the core accessory of clothing and apparel, the material and process of buttons directly affect the aesthetics, practicality and environmental protection of the product. At present, various materials are used to make buttons, mainly including shell buttons, resin buttons, nut buttons, metal buttons, leather buttons, etc. Among them, shell buttons are widely used in high-end apparel due to their elegant texture and bright color.

[0003] The manufacturing method of shell buttons is generally to punch and process complete shell pieces, but the material utilization rate of this method is very low, only 30%~40%. In order to improve the utilization rate of shell materials, the prior art also discloses a shell resin button, that is, the shell is encapsulated in a transparent resin layer, so that the button has the beauty of shell button and can improve the material utilization rate. For example, Chinese patent CN206260982U discloses a shell resin button, which composites a layer of transparent resin layer on a relatively thin shell layer (for example, 1mm~3mm), but the document does not disclose the preparation method of the shell resin button. In fact, when preparing the shell resin button, especially when preparing the shell resin button with small particle size shell particles as raw materials, how to ensure the yield of button products is one of the problems that need to be solved at present. SUMMARY

[0004] Therefore, the present application provides a resin composition containing shell particles, a shell resin button and a preparation method thereof. In the resin composition containing shell particles provided by the present application, the shell particles can be uniformly and stably suspended in the resin system, so as to ensure a high yield of button products and uniform and reliable quality.

[0005] The present application provides a resin composition containing shell particles, which comprises: 40wt%~60wt% of epoxy resin; 10wt%~20wt% of curing agent; 0.3wt%~2.0wt% of modified polyurea thickening agent; 0.1wt%~0.5wt% of coupling agent; The component B is 20wt%~40wt% of shell particles; The viscosity of the component A at 25℃ is 5000mPa s~20000mPa s; The sum of the mass percentages of the component A and the component B is 100%.

[0006] In some specific implementations, the particle size of the shell fragments is 0.1 mm to 2 mm.

[0007] In some specific implementations, the epoxy resin is E-51 type bisphenol A epoxy resin and PU-2080 polyether type PU prepolymer at a mass ratio of 100:10 to 30; The curing agent is T31 modified alicyclic amine curing agent and D-230 polyether amine curing agent at a mass ratio of 100:30 to 40; The modified polyurea thickening agent is one or more of BYK-420, R-1027, or Tego 685; The coupling agent is selected from γ-aminopropyl triethoxysilane or γ-glycidyl ether oxypropyl trimethoxysilane.

[0008] The application also provides a shell resin button obtained after curing of a shell-containing resin composition, the shell-containing resin composition comprising: component A and component B; The component A comprises: 40wt% to 60wt% of an epoxy resin; 10wt% to 20wt% of a curing agent; 0.3wt% to 2.0wt% of a modified polyurea thickening agent; 0.1wt% to 0.5wt% of a coupling agent; The component B is 20wt% to 40wt% of shell fragments; The viscosity of the component A at 25°C is 5000mPa s to 20000mPa s; The sum of the mass percentages of the component A and the component B is 100%.

[0009] In some specific implementations, the particle size of the shell fragments is 0.1 mm to 2 mm.

[0010] In some specific implementations, the epoxy resin is E-51 type bisphenol A epoxy resin and PU-2080 polyether type PU prepolymer at a mass ratio of 100:10 to 30; The curing agent is T31 modified alicyclic amine curing agent and D-230 polyether amine curing agent at a mass ratio of 100:30 to 40; The modified polyurea thickening agent is one or more of BYK-420, R-1027, or Tego 685; The coupling agent is selected from γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane.

[0011] This application provides a method for preparing a shell resin button, comprising the following steps: a) Mix 40wt%~60wt% epoxy resin, 10wt%~20wt% curing agent, 0.3wt%~2.0wt% modified polyurea thickener, and 0.1wt%~0.5wt% coupling agent to obtain component A; the viscosity of component A at 25°C is 5000 mPa. s~20000mPa s; b) Mix component A with 20wt%~40wt% shell fragments to obtain a resin composition containing shell fragments, wherein the total mass percentage of component A and component B is 100%; c) The resin composition containing shell fragments is sequentially molded, cured, and post-processed to obtain a shell resin button.

[0012] In some specific implementations, in step b), the shell fragments are prepared according to the following method: After the shells are crushed and sieved, they are then sterilized, roughened, and dried in sequence. The texturing process is carried out in dilute acid.

[0013] In some specific implementations, in step b), the mixing speed is 100 r / min to 150 r / min, and the mixing time is 5 min to 8 min.

[0014] In some specific implementations, step c) includes the curing process: Pre-cur at room temperature for 2-4 hours, then cure at 60-90℃ for 4-6 hours.

[0015] This application provides a resin composition containing seashell fragments, comprising: component A and component B, wherein component A comprises: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; and 0.1wt%~0.5wt% coupling agent; component B comprises 20wt%~40wt% seashell fragments; and component A has a viscosity of 5000 mPa at 25°C. s~20000mPa s; the total mass percentage of components A and B is 100%. This application controls the viscosity of component A, which contains epoxy resin, to 5000 mPa. s~20000mPa At 25℃, the uniform distribution of seashell fragments can be achieved, allowing denser seashell fragments to disperse and suspend evenly and stably in the epoxy resin system, thereby improving the yield of finished buttons. Furthermore, this application, through pretreatment of seashell fragments and modification with coupling agents, can enhance the bonding force between seashell fragments and the epoxy resin matrix, further improving the uniformity of seashell fragment distribution, ultimately achieving the goals of increasing the utilization rate of waste seashells, improving button quality and yield (to over 90%), simplifying the process, and reducing costs. Attached Figure Description

[0016] Figure 1 A photograph of the shell resin button prepared in Example 1 of this application; Figure 2 A photograph of the shell resin button prepared in Example 2 of this application; Figure 3 A photograph of the shell resin button prepared in Example 3 of this application; Figure 4 A photograph of the shell resin button prepared in Comparative Example 1 of this application; Figure 5 A photograph of the shell resin button prepared in Comparative Example 2 of this application; Figure 6 A photograph of the shell resin button prepared in Comparative Example 3 of this application; Figure 7 A photograph of the shell resin button prepared for Comparative Example 4 of this application. Detailed Implementation

[0017] It should be understood that the expression “one or more of…” individually includes each of the objects described after the expression, as well as various different combinations of two or more of the described objects, unless otherwise understood from the context and usage. The expression “and / or” combined with three or more described objects should be understood to have the same meaning, unless otherwise understood from the context.

[0018] The terms “including,” “having,” or “containing,” including the use of their grammatical synonyms, should generally be understood as open-ended and non-restrictive, for example, not excluding other unstated elements or steps, unless otherwise specifically stated or understood from the context.

[0019] It should be understood that the order of steps or the sequence of actions is not important as long as this application remains operational. Furthermore, two or more steps or actions can be performed simultaneously.

[0020] The use of any and all instances or exemplary language such as “e.g.” or “including” herein is merely intended to better illustrate the application and does not constitute a limitation on the scope of the application unless the claims are made. No language in this specification should be construed as indicating that any unclaimed element is essential to the practice of this application.

[0021] Furthermore, the numerical ranges and parameters used to define this application are approximate values, and the relevant values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inevitably contains standard deviations due to individual test methods. Therefore, unless otherwise explicitly stated, it should be understood that all ranges, quantities, values, and percentages used in this disclosure are modified with the word "approximately." Here, "approximately" generally means that the actual value is within plus or minus 10%, 5%, 1%, or 0.5% of a specific value or range.

[0022] This application provides a resin composition containing seashell fragments, comprising: component A and component B, wherein component A comprises: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; 0.1wt%~0.5wt% coupling agent; Component B consists of 20wt% to 40wt% shell fragments; The viscosity of component A at 25°C is 5000 mPa. s~20000mPa s; The total mass percentage of components A and B is 100%.

[0023] The resin composition provided in this application includes component A, wherein component A has a viscosity of 5000 mPa at 25°C. s~20000mPa s, preferably 6000 mPa s~19500mPa s, more preferably 6200 mPa s~19000mPa This application improves the yield of shell resin buttons by controlling the viscosity of component A, allowing the shell fragments to be uniformly and stably suspended in component A without settling. The resulting shell resin buttons are of uniform and reliable quality. In this application, the viscosity of component A at 25°C is less than 5000 mPa. At s, the shell fragments settle rapidly in the epoxy resin system, which affects the yield of shell resin buttons; the viscosity of component A at 25℃ is greater than 20000 mPa. When the flow rate is s, the material has poor fluidity, making it difficult to pour smoothly and prone to trapping air bubbles.

[0024] In this application, component A includes: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; 0.1wt%~0.5wt% of coupling agent.

[0025] Component A includes epoxy resin. As the resin matrix component of the shell resin button, the epoxy resin has good impact resistance, which is beneficial for improving the button's yield. In some specific implementations, the epoxy resin is E-51 type bisphenol A epoxy resin and PU-2080 polyether type PU prepolymer in a mass ratio of 100:10~30, and the mass ratio of E-51 type bisphenol A epoxy resin to PU-2080 polyether type PU prepolymer is 100:15~25. In some specific implementations, the epoxy value of the epoxy resin is 0.40eq / 100g~0.45eq / 100g, which not only has good adhesion and mechanical strength, but also better compatibility with shell fragments and thickeners. In some specific implementations, the amount of epoxy resin used is 40wt%~60wt%, preferably 45wt%~55wt%.

[0026] Component A includes a curing agent used to cure the epoxy resin. In some specific implementations, the curing agent preferably includes a T31 modified alicyclic amine curing agent, more preferably including a T31 modified alicyclic amine curing agent and a D-230 polyether amine curing agent. The active groups in the T31 modified alicyclic amine curing agent undergo a ring-opening reaction with epoxy groups to generate hydroxyl groups (-OH). The newly generated hydroxyl groups then react with the remaining epoxy groups to rapidly form a dense cross-linked network, enabling the adhesive to cure quickly and possess high strength. The D-230 polyether amine curing agent is an amino-terminated polyether whose molecular chain contains flexible polyoxypropylene segments and amino-terminated (-N) segments. The high steric hindrance, low reactivity, and slow crosslinking speed of the epoxy resin result in the embedding of flexible polyether segments into the generated crosslinking network, disrupting the regular structure of the rigid epoxy and increasing the toughness of the adhesive. The terminal amino groups react with the isocyanate groups (-NCO) of the PU-2080PU polyether prepolymer to form urea bonds, which synergistically enhance the toughness of the adhesive layer. In some specific implementations, the mass ratio of the T31 modified alicyclic amine curing agent to the D-230 polyether amine curing agent is 100:30~40, preferably 100:32~38. In some specific implementations, the amount of the curing agent is 10wt%~20wt%, preferably 12wt%~18wt%. In some specific implementations, the weight ratio of the curing agent to the epoxy resin is 1:2~3. At this weight ratio, the curing speed of the epoxy resin is moderate, the cured product has good toughness, and excessive button brittleness is avoided.

[0027] Component A includes a modified polyurea thickener, which can form a reversible three-dimensional network structure in the epoxy system through intermolecular association, thereby endowing the system with excellent thixotropic properties and precisely controlling the viscosity at 5000 mPa. s ~20000 mPa Within the range of s (25℃), uniform suspension of seashell fragments is achieved. In some specific implementations, the modified polyurea thickener includes, but is not limited to, BYK-420, R-1027, or Tego 685, and may be one or more of these. When the modified polyurea thickener is a combination of multiple substances, this application does not impose any special limitation on the mass ratio of each specific substance. In some specific implementations, the amount of the modified polyurea thickener is 0.3wt%~2.0wt%, preferably 0.5wt%~1.8wt%, and more preferably 0.5wt%~1.5wt%.

[0028] Component A includes a coupling agent, which can improve the interfacial bonding force between seashell fragments and epoxy groups, thereby enhancing the processing strength of the composite material. In some specific implementations, the coupling agent includes, but is not limited to, γ-aminopropyltriethoxysilane (KH-550) or γ-glycidoxypropyltrimethoxysilane (KH-560), and may be one or both. When the coupling agent is a combination of two substances, this application does not impose any special restrictions on the proportions of each specific substance. In some specific implementations, the coupling agent is preferably KH-560. In some specific implementations, the amount of the coupling agent is 0.1wt%~0.5wt%, preferably 0.15wt%~0.45wt%.

[0029] The resin composition containing shell fragments provided in this application further includes component B, which is shell fragments used to maintain the texture and luster of the shell in the button. In some specific implementations, the particle size of the shell fragments is 0.1 mm to 2 mm. In some specific implementations, to obtain different textures and lusters, the shell fragments are obtained by grading particles of different sizes, for example, using shell fragments with different particle size distributions such as 0.1 mm to 0.5 mm, 0.5 mm to 1.0 mm, 0.1 mm to 1.0 mm, or 1.0 mm to 2 mm. In some specific implementations, the shell fragments can be derived from shells such as muscarine, white-lipped oyster, black-lipped oyster, and oyster, preferably waste products from such shells, which can reduce costs.

[0030] In some specific implementations, the seashell fragments are preferably prepared according to the following method: After the shells are crushed and sieved, they undergo sterilization, texturing, and drying processes in sequence.

[0031] This application uses seashells or seashell waste as raw materials to prepare seashell fragments. When using seashell waste as raw material, the seashell waste is first cleaned to remove impurities, such as mud and organic matter adhering to its surface. This application does not have specific limitations on the method of cleaning impurities; scrubbing with a steel brush is sufficient to remove mud and organic matter. After removing mud and organic matter, it is preferable to use a mobile polishing machine to grind the seashells to remove stubborn impurities from their surface, and then rinse them with clean water 3 to 5 times. After washing, the obtained seashells are crushed. This application preferably uses a crusher to crush the seashells, and after crushing, they are sieved to select particles of 0.1 mm to 2 mm. After sieving, the obtained seashell particles are sterilized. This application preferably uses immersion in an ethanol solution for sterilization. In some specific implementations, the volume concentration of the ethanol solution is 60% to 80%, preferably 65% ​​to 75%, and more preferably 75%; the immersion time is 20 min to 30 min, preferably 22 min to 28 min. After soaking the seashell fragments in ethanol, they are rinsed with clean water to remove the ethanol. After cleaning, the obtained shell particles are subjected to a roughening treatment. This roughening treatment effectively increases the surface roughness of the shell fragments, giving them a roughened surface that significantly increases their interfacial bonding with the epoxy resin composition, making the shell fragments less prone to detachment during subsequent molding processes. In some specific implementations, the roughening treatment is performed in a dilute acid. In some specific implementations, the dilute acid includes, but is not limited to, dilute acetic acid, dilute hydrochloric acid, dilute nitric acid, or dilute sulfuric acid, and can be one or more of these. When the dilute acid is a combination of multiple substances, this application does not impose any special restrictions on the specific proportions of each substance. In some specific implementations, the mass concentration of the dilute acid is 0.1% to 1%, preferably 0.3% to 0.7%, and more preferably 0.5%. In some specific implementations, the roughening treatment is performed at room temperature for 5 to 10 minutes. After the roughening treatment, the obtained shell particles are dried to remove moisture, thus obtaining shell fragments. In some specific implementations, the drying temperature is 105℃~110℃, and the drying time is 2h~4h.

[0032] In some specific implementations, the amount of component B is 20wt% to 40wt%, preferably 25wt% to 35wt%. In some specific implementations, the total mass percentage of component A and component B is 100%.

[0033] This application does not impose any particular limitation on the preparation method of the resin composition containing shell fragments, but it is preferred to prepare it according to the following method: a) Mix 40wt%~60wt% epoxy resin, 10wt%~20wt% curing agent, 0.3wt%~2.0wt% modified polyurea thickener, and 0.1wt%~0.5wt% coupling agent to obtain component A; the viscosity of component A at 25°C is 5000 mPa. s~20000mPa s; b) Mix component A with 20wt% to 40wt% of shell fragments to obtain a resin composition containing shell fragments, wherein the total mass percentage of component A and component B is 100%.

[0034] This application first mixes epoxy resin, curing agent, modified polyurea thickener, and coupling agent. The specific types and amounts of epoxy resin, curing agent, modified polyurea thickener, and coupling agent are as described above, and this application has no particular limitations. Specifically, this application first mixes epoxy resin and curing agent, and then mixes them with modified polyurea thickener and coupling agent to obtain component A. In some specific implementations, the mixing is carried out under stirring conditions, and the stirring speed is 200 r / min to 300 r / min, preferably 220 r / min to 280 r / min. In some specific implementations, the mixing temperature is room temperature, and the time is 15 min to 40 min. Specifically, the mixing time of epoxy resin and curing agent is 1 min to 10 min, and the mixing time of modified polyurea thickener and coupling agent is 10 min to 30 min.

[0035] After obtaining component A, it is mixed with component B to obtain a resin composition containing shell fragments. The selection and amount of component B are as described above and will not be repeated here. Specifically, the shell fragments are slowly added to component A, preferably under stirring conditions. The stirring speed is 100 r / min to 150 r / min, and the stirring time is 5 min to 8 min. In this application, low-speed stirring helps to avoid generating too many bubbles and ensures that the shell fragments are uniformly dispersed in the epoxy resin composition. After uniform mixing, a resin composition containing shell particles is obtained.

[0036] The resin composition provided in this application has an appropriate viscosity, which enables the shell fragments to be uniformly and stably suspended in the resin system without settling, thereby ensuring the yield of the obtained buttons.

[0037] This application also provides a shell resin button, which is obtained by curing the resin composition containing shell fragments described in the above-mentioned technical solution. In the shell resin button provided by this application, the shell fragments are evenly distributed in the resin, resulting in a good appearance and a high yield.

[0038] This application obtains a shell resin button by sequentially molding, curing, and post-processing the resin composition containing shell fragments obtained from the above technical solution.

[0039] Specifically, after obtaining the resin composition containing seashell particles, this application pours it into a button mold for curing. In some specific implementations, the button mold is preheated to a temperature of 40°C to 45°C. In some specific implementations, the inner wall of the button mold is pre-sprayed with a release agent to facilitate demolding.

[0040] In some specific implementations, the solidification includes: Pre-cur at room temperature for 2-4 hours, then cure at 60-90℃ for 4-6 hours.

[0041] Specifically, this application first pre-cures the button mold at room temperature for 2-4 hours to allow the material to initially take shape, and then cures it at 60℃-90℃ for 4-6 hours to ensure complete curing, forming the button blank. In some specific implementations, the pre-curing time is preferably 2.5-3.5 hours. In some specific implementations, the curing temperature is preferably 65℃-85℃, more preferably 70℃-80℃, and the curing time is preferably 4.5-5.5 hours. During the curing process, the heating rate is preferably no more than 5℃ / min to avoid sudden temperature rises that could cause internal stress cracks.

[0042] After curing, the obtained button blank is post-processed to obtain a shell resin button. In some specific implementations, the post-processing specifically includes: After the button blank has solidified, it is removed from the mold and shaped. The diameter, thickness and edge curvature of the button are adjusted according to the design size, and the dimensional deviation is controlled to be ≤±0.2mm. Then, the hole is drilled, and the hole position deviation is controlled to be ≤0.1mm. Finally, the button is placed in a roller polishing machine and polished with a mixture of abrasive, 500-grit polishing powder and water. The polishing speed is controlled at 60r / min~100r / min and the polishing time is 6h~12h to remove surface burrs and processing marks, so as to obtain a finished button with a smooth surface and uniform texture.

[0043] This application provides a resin composition containing seashell fragments, comprising: component A and component B, wherein component A comprises: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; and 0.1wt%~0.5wt% coupling agent; component B comprises 20wt%~40wt% seashell fragments; and component A has a viscosity of 5000 mPa at 25°C. s~20000mPa s; the total mass percentage of components A and B is 100%. This application controls the viscosity of component A, which contains epoxy resin, to 5000 mPa. s~20000mPa At 25℃, the uniform distribution of seashell fragments can be achieved, ensuring that the denser seashell fragments are evenly and stably dispersed and suspended in the epoxy resin system, thereby improving the yield of buttons. Furthermore, this application, through pretreatment of the seashell fragments and modification with coupling agents, enhances the bonding force between the seashell fragments and the epoxy resin matrix, preventing fragments from falling off during the molding process. It also further improves the uniformity of the seashell fragment distribution, ultimately achieving the goals of increasing the utilization rate of waste seashells, improving button quality and yield (to over 90%), simplifying the process, and reducing costs. Furthermore, this application uses a compound system of epoxy resin and curing agent, ensuring that the button blank possesses both strength and toughness, meeting subsequent processing requirements. Moreover, this application has a simple process, eliminating the need for complex layered casting, resulting in good product consistency and high production efficiency. Experimental results show that the method provided in this application can increase the yield of shell resin buttons to over 90%, with good raw material utilization. Moreover, the prepared shell resin buttons have uniformly distributed shell fragments, complete curing, good button blank toughness, no chipping or fragment shedding during shaping and processing, and a smooth surface.

[0044] The present invention is further illustrated below with reference to the embodiments. The scope of protection of the present invention is not limited to the following embodiments.

[0045] In the following embodiments and comparative examples, the shell fragments were obtained according to the following methods: Collect shell waste, use a steel brush to remove the mud and organic matter attached to the surface, then use a mobile polishing machine to grind it to remove stubborn impurities on the surface, and rinse it with clean water 3 to 5 times; The cleaned shell waste is fed into a crusher for crushing, and then graded and screened through a standard sieve of a predetermined particle size to obtain shell fragments of a predetermined particle size. For example, when the shell fragments have a particle size of 0.5mm to 1mm, they can be screened through standard sieves of 0.5mm and 1mm respectively. The screened shell fragments were immersed in a 75% (v / v) ethanol solution for 20-30 minutes for sterilization, and then rinsed with clean water. The cleaned shell fragments are immersed in a texturing solution made of 5% dilute hydrochloric acid for 5 to 10 minutes. They are then removed and dried at 105°C to 110°C for 2 to 4 hours to remove moisture, thus obtaining texturized shell fragments.

[0046] In the following embodiments, all proportions of substances are mass ratios.

[0047] Example 1

[0048] Prepare shell resin buttons according to the following formula: Epoxy resin (E-51:PU-2080=100:15, epoxy value 0.435eq / 100g): 48wt% Hardener (T31:D-230=100:35): 22wt%; Modified polyurea thickener (BYK-420): 1.5wt%; Shell fragments (0.5mm~1.0mm): 28wt% Coupling agent (KH-560): 0.5wt%; The preparation method is as follows: Weigh the epoxy resin and curing agent, pour them into a mixing tank, and mix at a stirring rate of 250 r / min for 5 min. After mixing evenly, add the modified polyurea thickener and coupling agent, and continue stirring at a rate of 250 r / min for 25 min to form an epoxy resin composition. The epoxy resin composition was tested, and its measured viscosity at 25°C was approximately 16000 mPa·s. The shell fragments were slowly added to the above epoxy resin composition and stirred at 120 r / min for 7 min to obtain an epoxy resin composition containing shell fragments. The epoxy resin composition containing seashell fragments is poured into a button mold preheated to 40℃~45℃ (the inner wall of the mold needs to be sprayed with a release agent beforehand). The mold is pre-cured at 25℃ for 2.5h to allow the material to initially set. Then it is transferred to a constant temperature oven and cured at 80℃ for 5h. After complete curing, a button blank is formed. During the curing process, the heating rate needs to be controlled to ≤5℃ / min. After the button blank has solidified, it is removed from the mold and shaped. The diameter, thickness and edge curvature of the button are adjusted according to the design size, and the dimensional deviation is controlled to be ≤±0.2mm. Then, the hole is drilled, and the hole position deviation is controlled to be ≤0.1mm. Finally, the button is placed in a roller polishing machine and polished with a mixture of abrasive, 500-grit polishing powder and water. The polishing speed is controlled at 80r / min and the polishing time is 10h to remove surface burrs and processing marks, and the shell resin button is obtained.

[0049] See Figure 1 , Figure 1 The images show photographs of the shell resin button prepared in Example 1 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 1 It is known that the shell resin buttons prepared in this application have uniformly distributed shell fragments, are completely cured, have good toughness, and are smooth with no chipping or fragment shedding during shaping and processing.

[0050] Example 2

[0051] Prepare shell resin buttons according to the following formula: Epoxy resin (E-51:PU-2080=100:25, epoxy value 0.405eq / 100g): 43.5wt% Hardener (T31:D-230=100:30): 16.5wt%; Modified polyurea thickener (R-1027): 0.5 wt%; Shell fragments (0.1mm~0.5mm): 39wt%; Coupling agent (KH-560): 0.5wt%; The preparation method is as follows: Weigh the epoxy resin and curing agent, pour them into a mixing tank, and mix at a stirring rate of 250 r / min for 5 min. After mixing evenly, add the modified polyurea thickener and coupling agent, and continue stirring at a rate of 250 r / min for 20 min to form an epoxy resin composition. The epoxy resin composition was tested, and its measured viscosity at 25°C was approximately 7000 mPa·s. The shell fragments were slowly added to the above epoxy resin composition and stirred at 120 r / min for 7 min to obtain an epoxy resin composition containing shell fragments. The epoxy resin composition containing seashell fragments is poured into a button mold preheated to 40℃~45℃ (the inner wall of the mold needs to be sprayed with a release agent beforehand). The mold is pre-cured at 25℃ for 3 hours to allow the material to be initially shaped. Then it is transferred to a constant temperature oven and cured at 70℃ for 6 hours. After complete curing, a button blank is formed. During the curing process, the heating rate needs to be controlled to ≤5℃ / min. After the button blank has solidified, it is removed from the mold and shaped. The diameter, thickness and edge curvature of the button are adjusted according to the design size, and the dimensional deviation is controlled to be ≤±0.2mm. Then, the hole is drilled, and the hole position deviation is controlled to be ≤0.1mm. Finally, the button is placed in a roller polishing machine and polished with a mixture of abrasive, 500-grit polishing powder and water. The polishing speed is controlled at 80r / min and the polishing time is 10h to remove surface burrs and processing marks, and the shell resin button is obtained.

[0052] See Figure 2 , Figure 2 The images show photographs of the shell resin button prepared in Example 2 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 2 It is known that the small-diameter shell fragments in the shell resin buttons prepared in this application exhibit a fine and uniform texture, and the buttons have good flexibility and impact resistance.

[0053] Example 3

[0054] Prepare shell resin buttons according to the following formula: Epoxy resin (E-51:PU-2080=100:20, epoxy value 0.420eq / 100g): 47wt% Hardener (T31:D-230=100:40): 23wt% Modified polyurea thickener (Tego 685): 2.0 wt%; Shell fragments (1.0mm~2.0mm): 27.5wt% Coupling agent (KH-560): 0.5wt%; The preparation method is as follows: Weigh the epoxy resin and curing agent, pour them into a mixing tank, and mix at a stirring rate of 250 r / min for 5 min. After mixing evenly, add the modified polyurea thickener and coupling agent, and continue stirring at a rate of 250 r / min for 20 min to form an epoxy resin composition. The epoxy resin composition was tested, and its measured viscosity at 25°C was approximately 19500 mPa·s. The shell fragments were slowly added to the above epoxy resin composition and stirred at 120 r / min for 7 min to obtain an epoxy resin composition containing shell fragments. The epoxy resin composition containing seashell fragments is poured into a button mold preheated to 40℃~45℃ (the inner wall of the mold needs to be sprayed with a release agent beforehand). The mold is pre-cured at 25℃ for 4 hours to allow the material to initially set. Then it is transferred to a constant temperature oven and cured at 85℃ for 4.5 hours. After complete curing, a button blank is formed. During the curing process, the heating rate needs to be controlled to ≤5℃ / min. After the button blank has solidified, it is removed from the mold and shaped. The diameter, thickness and edge curvature of the button are adjusted according to the design size, and the dimensional deviation is controlled to be ≤±0.2mm. Then, the hole is drilled, and the hole position deviation is controlled to be ≤0.1mm. Finally, the button is placed in a roller polishing machine and polished with a mixture of abrasive, 500-grit polishing powder and water. The polishing speed is controlled at 80r / min and the polishing time is 10h to remove surface burrs and processing marks, and the shell resin button is obtained.

[0055] See Figure 3 , Figure 3 The images show photographs of the shell resin button prepared in Example 3 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 3 It is evident that the shell resin buttons prepared in this application exhibit excellent suspension of large-diameter shell fragments with no significant sedimentation, resulting in a dense product structure and good toughness.

[0056] Comparative Example 1

[0057] Prepare shell resin buttons according to the following formula: Epoxy resin (E-44:PU-2080 = 100:15, epoxy value 0.370 eq / 100g): 50wt% Hardener (T31:D-230 = 100:35): 21.5wt%; Modified polyurea thickener (BYK-420): 0.1wt%; Shell fragments (0.5-1.0 mm): 28 wt%; Coupling agent (KH-560): 0.4wt%; When preparing the epoxy resin composition according to the method of Example 1, it was found that the resin mixture was slightly turbid and had poor compatibility. The measured viscosity of the prepared epoxy resin composition at 25°C was approximately 3800 mPa·s.

[0058] After adding seashell fragments to the epoxy resin composition and allowing it to stand for a short time, significant sedimentation was observed. Seashell resin buttons were prepared using the same method as in Example 1. (See [link to Example 1]). Figure 4 , Figure 4 The images show photographs of the shell resin button prepared in Comparative Example 1 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 4 As can be seen, the distribution of shell fragments in the shell resin button prepared in Comparative Example 1 of this application is extremely uneven. During the shaping and processing, a large number of fragments fall off due to agglomeration and loss, resulting in a low yield. In addition, due to the poor compatibility of the E-44 epoxy resin system and its low epoxy value, the matrix of the cured product itself has insufficient strength, which further reduces the mechanical properties of the button.

[0059] Comparative Example 2

[0060] Prepare shell resin buttons according to the following formula: Epoxy resin (E-51:PU-2080=100:15, epoxy value 0.435eq / 100g): 47.5wt% Hardener (T31:D-230=100:35): 20.5wt% Modified polyurea thickener (BYK-420): 3.0 wt% Shell fragments (0.5mm~1.0mm): 28wt% Coupling agent (KH-560): 0.5wt%; An epoxy resin composition was prepared according to the method in Example 1. The measured viscosity of the prepared epoxy resin composition at 25°C was approximately 26000 mPa·s.

[0061] Adding seashell fragments to the epoxy resin composition resulted in extremely poor material flowability, making casting difficult, and trapping a large number of air bubbles that were difficult to remove. Seashell resin buttons were prepared using the same method as in Example 1, see [link to example]. Figure 5 , Figure 5 The images show photographs of the shell resin button prepared in Comparative Example 2 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 5 It is evident that the shell resin button prepared in Comparative Example 2 of this application contains a large number of air bubbles, which does not meet the standards for qualified products.

[0062] Comparative Example 3

[0063] Prepare shell resin buttons according to the following formula: Epoxy resin (E-44:PU-2080 = 100:15, epoxy value 0.370 eq / 100g): 49.5 wt%; Hardener (T31): 21wt%; Modified polyurea thickener (BYK-420): 0.9wt%; Shell fragments (0.5-1.0 mm): 28 wt%; Coupling agent (KH-560): 0.6wt%; An epoxy resin composition was prepared according to the method in Example 1. The measured viscosity of the prepared epoxy resin composition at 25°C was approximately 13800 mPa·s.

[0064] After adding seashell fragments to the epoxy resin composition, a seashell resin button was prepared according to the same method as in Example 1. (See Example 1) Figure 6 , Figure 6 The images show photographs of the shell resin button prepared in Comparative Example 3 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 6 It can be seen that, from Figure 6 It can be seen that in the shell resin button prepared in Comparative Example 3 of this application, due to the significantly increased brittleness of the curing system, microcracks are easily generated on the edge of the button during machining, and the impact resistance test performance is poor.

[0065] Comparative Example 4

[0066] Prepare shell resin buttons according to the following formula: Epoxy resin (E-51:PU-2080 = 100:15, epoxy value 0.435eq / 100g): 48wt% Hardener (T31:D-230=100:35): 22 wt% Modified polyurea thickener (BYK-420): 1.5wt%; Shell fragments (0.5-1.0 mm, unprocessed): 28 wt%; Coupling agent (KH-560): 0.5wt%; An epoxy resin composition was prepared according to the method of Example 1. The measured viscosity of the prepared epoxy resin composition at 25°C was approximately 15800 mPa·s.

[0067] The pretreatment of the shell fragments only went up to the sterilization step (i.e., washing, crushing, sieving, ethanol soaking sterilization, washing and drying), omitting the texturing step. The rest of the preparation process was exactly the same as in Example 1.

[0068] After adding seashell fragments to the epoxy resin composition, a seashell resin button was prepared according to the same method as in Example 1. (See Example 1) Figure 7 , Figure 7 The images show photographs of the shell resin button prepared in Comparative Example 4 of this application, with the left image being a cross-sectional photograph of the shell resin button and the right image being a frontal photograph of the shell resin button. Figure 7 As can be seen, in the shell resin button prepared in Comparative Example 4 of this application, the macroscopic distribution of shell fragments in the matrix is ​​basically uniform, indicating that the viscosity control is effective. Even with appropriate resin viscosity and the use of a coupling agent, the interfacial bonding force between the fragments and the matrix is ​​still insufficient and cannot withstand the stress brought about by mechanical processing, resulting in a sharp increase in the shedding rate. During the subsequent processing, the shedding of shell fragments is very significant.

[0069] The product performance of the shell resin buttons prepared in Examples 1-3 and Comparative Examples 1-4 was tested respectively. The results are shown in Table 1. Table 1 shows the product performance results of the shell resin buttons prepared in the examples and comparative examples.

[0070] Table 1. Product performance results of the shell resin buttons prepared in the examples and comparative examples.

[0071] As shown in Table 1, this application achieves its viscosity at 5000 mPa by using a specific compounded epoxy resin system and a modified polyurea thickener. s~20000mPa At s, shell fragments with a particle size of 0.1mm~2mm can be uniformly and stably suspended in epoxy resin without settling; at the same time, the optimized curing agent compounding scheme ensures that the cured product has both strength and toughness, thereby improving the yield of shell resin buttons and ensuring uniform and reliable quality.

[0072] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and inventive concept of this application, should be included within the scope of protection of this application.

Claims

1. A resin composition containing seashell fragments, comprising: Component A and component B, wherein component A comprises: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; 0.1wt%~0.5wt% coupling agent; Component B consists of 20wt% to 40wt% shell fragments, with a particle size of 0.1mm to 2mm. The shell particles have undergone a roughening process, resulting in a roughened surface. The viscosity of component A at 25°C is 5000 mPa•s to 20000 mPa•s; The total mass percentage of components A and B is 100%.

2. The resin composition according to claim 1, characterized in that, The epoxy value of the epoxy resin is 0.40 eq / 100g to 0.45 eq / 100g.

3. The resin composition according to claim 1, characterized in that, The epoxy resin is E-51 type bisphenol A epoxy resin and PU-2080 polyether type PU prepolymer with a mass ratio of 100:10~30; The curing agent is a combination of T31 modified alicyclic amine curing agent and D-230 polyether amine curing agent with a mass ratio of 100:30~40; The modified polyurea thickener is one or more of BYK-420, R-1027, or Tego 685; The coupling agent is selected from γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane.

4. A seashell resin button, obtained by curing a resin composition containing seashell fragments, wherein the resin composition containing seashell fragments comprises: Component A and component B; Component A includes: 40wt%~60wt% epoxy resin; 10wt%~20wt% curing agent; 0.3wt%~2.0wt% modified polyurea thickener; 0.1wt%~0.5wt% coupling agent; Component B consists of 20wt% to 40wt% shell fragments, with a particle size of 0.1mm to 2mm. The shell particles have undergone a roughening process, resulting in a roughened surface. The viscosity of component A at 25°C is 5000 mPa•s to 20000 mPa•s; The total mass percentage of components A and B is 100%.

5. The shell resin button according to claim 4, characterized in that, The epoxy value of the epoxy resin is 0.40 eq / 100g to 0.45 eq / 100g.

6. The shell resin button according to claim 4, characterized in that, The epoxy resin is E-51 type bisphenol A epoxy resin and PU-2080 polyether type PU prepolymer with a mass ratio of 100:10~30; The curing agent is a combination of T31 modified alicyclic amine curing agent and D-230 polyether amine curing agent with a mass ratio of 100:30~40; The modified polyurea thickener is one or more of BYK-420, R-1027, or Tego 685; The coupling agent is selected from γ-aminopropyltriethoxysilane or γ-glycidoxypropyltrimethoxysilane.

7. A method for preparing a seashell resin button, comprising the following steps: a) Mix 40wt%~60wt% epoxy resin, 10wt%~20wt% curing agent, 0.3wt%~2.0wt% modified polyurea thickener and 0.1wt%~0.5wt% coupling agent to obtain component A; the viscosity of component A at 25°C is 5000mPa•s~20000mPa•s; b) Mix component A with 20wt%~40wt% shell fragments to obtain a resin composition containing shell fragments, wherein the total mass percentage of component A and component B is 100%; c) The resin composition containing shell fragments is sequentially molded, cured, and post-processed to obtain a shell resin button.

8. The preparation method according to claim 7, characterized in that, In step b), the shell fragments are prepared according to the following method: After the shells are crushed and sieved, they are then sterilized, roughened, and dried in sequence. The texturing process is carried out in dilute acid.

9. The preparation method according to claim 7, characterized in that, In step b), the mixing speed is 100 r / min to 150 r / min, and the mixing time is 5 min to 8 min.

10. The preparation method according to claim 7, characterized in that, In step c), the curing includes: Pre-cur at room temperature for 2-4 hours, then cure at 60-90℃ for 4-6 hours.

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