A material and manufacturing process that is resistant to breakage and staining

Abstract

This invention relates to the field of polymer composite materials technology, and discloses a material and manufacturing process for resistance to damage and staining. The manufacturing process includes: weighing unsaturated polyester resin, aluminum hydroxide and / or magnesium hydroxide, quartz powder and / or calcium carbonate, organically modified montmorillonite, ammonium polyphosphate crystal form II, and anhydrous calcium borate according to the formula, mixing them to form a homogeneous slurry, then casting it into a gel mold, and finally curing and demolding it to obtain the product. This invention uses high aspect ratio organically modified montmorillonite sheets to fill the micropores on the surface of the product, and uses anhydrous calcium borate to replace zinc borate containing crystal water to eliminate pores during the curing stage. The two work synergistically to reduce surface porosity and achieve long-lasting stain resistance; using extremely low water solubility ammonium polyphosphate crystal form II to replace water-soluble phosphates ensures long-term stable flame retardant performance and batch consistency; the absence of anhydrous calcium borate eliminates interference with curing accelerators, resulting in stable molding quality; and each flame-retardant component takes effect sequentially in the low-temperature, medium-temperature, and high-temperature ranges, forming continuous flame-retardant protection across the entire temperature range.

Description

Technical Field

[0001] This invention relates to the field of polymer composite materials technology, and more specifically, to a material and manufacturing process that is resistant to breakage and staining. Background Technology

[0002] Artificial stone washbasins are made by casting unsaturated polyester resin as the matrix and mineral powder as the filler, and are widely used in the bathroom industry. Existing halogen-free flame-retardant artificial stone formulations typically incorporate large amounts of aluminum hydroxide (ATH) or magnesium hydroxide (MH) as the main flame-retardant filler, and zinc borate (… The above method uses diammonium hydrogen phosphate as a low-temperature charring auxiliary component and a flame retardant synergist as a diammonium hydrogen phosphate synergist. However, the above method has the following technical problems: In order to achieve the amount of ATH / MH required for effective flame retardancy, a large amount of the above filler must be added to the formulation. When a large amount of ATH / MH particles are accumulated, interparticle pores are formed, which increases the open porosity of the product surface; Zinc borate, as a synergist, contains 3.5 molecules of water of crystallization, which can be released prematurely at the resin post-curing temperature stage, forming bubbles and remaining on the product surface in the form of pores, further aggravating the surface porosity problem; The introduction of a high proportion of ATH / MH reduces the toughness of the resin matrix and increases its brittleness, resulting in insufficient product breakage resistance.

[0003] Furthermore, the low-temperature charring auxiliary component, diammonium hydrogen phosphate, has strong water solubility (approximately 57.5 g / 100 mL, 25℃), and gradually dissolves and is lost in the long-term water contact environment of a washbasin. The low-temperature charring flame-retardant effect diminishes with age. Additionally, diammonium hydrogen phosphate reacts prematurely with ATH during the mixing stage, forming aluminum phosphate precipitate, consuming the effective amount of both flame-retardant components, leading to unstable flame-retardant performance. (The text abruptly shifts to a seemingly unrelated topic: zinc borate...) The ions compete with the accelerator (cobalt naphthenate) in the resin curing system for complexation, which reduces the effective accelerator concentration, causing the resin gel time to fluctuate between batches and the product curing quality to be unstable. Summary of the Invention

[0004] This invention provides a material and manufacturing process that are resistant to breakage and stains, solving the technical problems of high surface porosity, poor stain resistance, insufficient breakage resistance, poor long-term stability of flame retardant properties, and batch-to-batch fluctuations in the molding quality of artificial stone products in related technologies.

[0005] This invention provides a manufacturing process for a material that is resistant to breakage and staining. The material uses unsaturated polyester resin as a matrix and halogen-free flame-retardant fillers and mineral fillers as fillers, and is obtained through casting molding and post-curing. The following raw materials are weighed according to the total mass fraction of the formula: Unsaturated polyester resin 15-25%, aluminum hydroxide 45-60% or a combination of aluminum hydroxide 30-50% and magnesium hydroxide 5-15% (total aluminum hydroxide and magnesium hydroxide 45-60%), quartz powder and / or calcium carbonate 5-15% total, organically modified montmorillonite 2-6%, ammonium polyphosphate crystal form II 3-10%, anhydrous calcium borate ( 2-8%, and the sum of the mass fractions of the above components is 100%; Separately, use methyl ethyl ketone peroxide as an initiator, at a dosage of 0.5% to 2.0% of the resin mass, and cobalt naphthenate as an accelerator, at a dosage of 0.1% to 0.5% of the resin mass; After uniformly mixing the above solid components with resin and accelerator, an initiator is added to form a homogeneous slurry. The slurry is poured into a mold and allowed to stand at 20-25°C to gel and form. The product is then kept at 60-80°C for 1-2 hours to cure. After demolding, the material is obtained.

[0006] Preferably, the unsaturated polyester resin is an orthophthalic or isophthalic unsaturated polyester resin with a viscosity of 500–1500 mPa·s at 25°C.

[0007] Preferably, the aluminum hydroxide has an average particle size of 5–50 μm.

[0008] Preferably, the formulation also contains magnesium hydroxide, the amount of which is 5-15% of the total mass of the formulation, and the average particle size of the magnesium hydroxide is 5-50 μm; the total amount of aluminum hydroxide and magnesium hydroxide is 45-60% of the total mass of the formulation.

[0009] Preferably, the average particle size of the quartz powder is 10-100 μm, and the average particle size of the calcium carbonate is 5-50 μm; when the quartz powder and calcium carbonate are used simultaneously, the mass ratio of the two is 1:1 to 3:1.

[0010] Preferably, the organically modified montmorillonite is prepared by intercalation modification of montmorillonite with a long-chain alkyl quaternary ammonium salt organic modifier, and its monolayer thickness is 0.9-1.1 nm with an aspect ratio of not less than 100:1.

[0011] Preferably, the accelerator cobalt naphthenate is calculated as 6% by mass of cobalt.

[0012] Preferably, the mixing step specifically involves: adding each solid component, resin, and accelerator into a mixing container and stirring for 15-30 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; adding the initiator just before pouring and stirring for 3-5 minutes; and completing the pouring operation within 30 minutes after adding the initiator; the initiator and accelerator must be added in steps and should not be directly mixed.

[0013] Preferably, the casting molding step specifically involves: injecting the homogeneous slurry into the mold and letting it stand at 20-25°C for 30-90 minutes; when the slurry surface does not stick when lightly touched with a finger and the product has a certain shape retention ability, the gel molding is considered complete; the post-curing step specifically involves: keeping the gel product together with the mold at 60-80°C for 1-2 hours; after post-curing, cooling to room temperature before demolding.

[0014] The beneficial effects of this invention are as follows: This invention uses organically modified montmorillonite with high aspect ratio sheets to fill the fine pore channels on the surface of the product, and replaces zinc borate containing crystal water with anhydrous calcium borate, fundamentally eliminating the surface pores formed by moisture release during the curing stage. The two work together to significantly reduce the open porosity of the product surface, resulting in significant and long-lasting anti-fouling performance. The use of quartz powder and / or calcium carbonate structural fillers to replace part of the ATH / MH alleviates the increased matrix brittleness caused by the introduction of a high proportion of ATH / MH. The deflection effect of the organically modified montmorillonite lamellae on the crack propagation path further improves the damage resistance. The formula does not contain any halogen flame retardants and does not produce toxic hydrogen halide gas when burning, meeting safety and environmental protection requirements. Replacing water-soluble phosphates with ammonium polyphosphate crystal form II, which has extremely low water solubility, does not reduce flame retardant performance in long-term water environments and does not react prematurely with ATH during the mixing stage, resulting in stable flame retardant performance between batches. Anhydrous calcium borate does not contain This eliminates competitive complexation interference with resin curing accelerators, ensuring consistent batch-to-batch product molding quality. Each flame-retardant component takes effect sequentially in the low-temperature, medium-temperature, and high-temperature ranges, forming continuous flame-retardant protection covering the entire temperature range. The inorganic mineral phases such as calcium aluminate generated in the high-temperature stage ensure the integrity of the high-temperature residue structure. Attached Figure Description

[0015] Figure 1 This is a bar chart comparing the open porosity of the three groups of samples in Experiment 1 of this invention; Figure 2 This is a bar chart comparing the surface antifouling ratings of the three groups of samples in Experiment 1 of this invention; Figure 3 These are comparison images of the cross-section of control sample A and the product of Example 2 in Experiment 1 of this invention using scanning electron microscope (SEM). Figure 4 This is a bar chart comparing the limiting oxygen index (LOI) of each sample in Experiment 2 of this invention; Figure 5 This is a bar chart comparing the peak heat release rate (PHRR) of each sample in Experiment 2 of this invention; Figure 6 This is a line graph showing the change of LOI over time after water immersion in Experiment 3 of this invention; Figure 7 This is a grouped bar chart comparing the Charpy notched impact strength and flexural strength of each group of samples in Experiment 4 of this invention. Detailed Implementation

[0016] The subject matter described herein will now be discussed with reference to exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and implement the subject matter described herein, and changes may be made to the function and arrangement of the elements discussed without departing from the scope of this specification. Various processes or components may be omitted, substituted, or added as needed in the examples. Furthermore, some features described in the examples may be combined in other examples.

[0017] Example 1 This embodiment discloses a manufacturing process for a material that is resistant to breakage and staining, the process comprising the following steps: Step 1: Weigh each raw material component according to the formula mass fraction. Weigh out the following components according to the total mass fraction of the formula: 25% of phthalic unsaturated polyester resin (viscosity 500 mPa·s at 25℃, hereinafter referred to as "resin"); Aluminum hydroxide (ATH, average particle size 5 μm) 50%, without magnesium hydroxide; calcium carbonate (average particle size 5 μm) 10%, without quartz powder; Organically modified montmorillonite (OMMT, prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifiers, with a single layer thickness of 0.9 nm and an aspect ratio of not less than 100:1) 2%; Ammonium polyphosphate (APP, crystal form II) 8%; Anhydrous calcium borate ( 5%; The sum of the mass fractions of the above components is 100%. Additionally, the amount of initiator (methyl ethyl ketone peroxide, MEKP) is 1.5% of the resin mass; and the amount of accelerator (cobalt naphthenate, calculated as 6% cobalt by mass) is 0.4% of the resin mass.

[0018] Step 2: Mixing to prepare a homogeneous slurry Add the resin, ATH, calcium carbonate, OMMT, APP crystal form II, and anhydrous calcium borate weighed in step one to a mixing container, add the accelerator (cobalt naphthenate), and stir for 30 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; add the initiator (MEKP) just before pouring, stir for 3 minutes to prepare a homogeneous slurry; complete the pouring operation in step three within 30 minutes after adding the initiator; the initiator and accelerator must be added in steps and should not be directly mixed to prevent premature polymerization reaction.

[0019] Step 3: Casting the gel to form a mold The homogeneous slurry is injected into the mold and left to stand at 20°C for 30 minutes. The slurry polymerizes and gels under the combined action of the initiator and accelerator. When the surface of the slurry does not stick when lightly touched with a finger and the product has a certain shape retention ability, the gelation is considered to be complete.

[0020] Step 4: Post-curing and demolding The gel product, along with the mold, is transferred to an oven and cured at 80°C for 1 hour to allow the resin to fully cross-link and cure. After curing, the product is removed and allowed to cool naturally to room temperature outside the oven before demolding, resulting in a durable and stain-resistant artificial stone product.

[0021] Example 2 This embodiment discloses a manufacturing process for a material that is resistant to breakage and staining, the process comprising the following steps: Step 1: Weigh each raw material component according to the formula mass fraction. Weigh the following components according to the total mass fraction of the formula for later use: isophthalic unsaturated polyester resin (viscosity 800 mPa·s at 25℃, hereinafter referred to as "resin") 20%; aluminum hydroxide (ATH, average particle size 20 μm) 40%; magnesium hydroxide (MH, average particle size 20 μm) 10%, ATH and MH combined 50%; quartz powder (average particle size 50 μm) 8% and calcium carbonate (average particle size 20 μm) 4%, used in a mass ratio of 2:1, totaling 12%; organically modified montmorillonite (OMMT, prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifier, single layer thickness 1.0 nm, aspect ratio 150:1) 4%; ammonium polyphosphate (APP, crystal form II) 8%; anhydrous calcium borate ( 6%; the sum of the mass fractions of the above components is 100%. Additionally, the amount of initiator (methyl ethyl ketone peroxide, MEKP) is 1.0% of the resin mass; the amount of accelerator (cobalt naphthenate, calculated as 6% cobalt by mass) is 0.3% of the resin mass.

[0022] Step 2: Mixing to prepare a homogeneous slurry Add the resin, ATH, MH, quartz powder, calcium carbonate, OMMT, APP crystal form II, and anhydrous calcium borate weighed in step one to a mixing container, add the accelerator (cobalt naphthenate), and stir for 20 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; add the initiator (MEKP) just before pouring, stir for 4 minutes to make a homogeneous slurry; complete the pouring operation in step three within 30 minutes after adding the initiator; the initiator and accelerator must be added in steps and must not be directly mixed.

[0023] Step 3: Casting the gel to form a mold The homogeneous slurry is injected into the mold and left to stand at 23°C for 60 minutes. The slurry polymerizes and gels under the combined action of the initiator and accelerator. When the surface of the slurry does not stick when lightly touched with a finger and the product has a certain shape retention ability, the gelation is considered to be complete.

[0024] Step 4: Post-curing and demolding The gel product, along with the mold, is transferred to an oven and cured at 70°C for 1.5 hours to allow the resin to fully cross-link and cure. After curing, the product is removed and allowed to cool naturally to room temperature outside the oven before demolding, resulting in a durable and stain-resistant artificial stone product.

[0025] Example 3 This embodiment discloses a manufacturing process for a material that is resistant to breakage and staining, the process comprising the following steps: Step 1: Weigh each raw material component according to the formula mass fraction. Weigh the following components according to the total mass fraction of the formula for later use: isophthalic unsaturated polyester resin (viscosity 1500 mPa·s at 25℃, hereinafter referred to as "resin") 15%; aluminum hydroxide (ATH, average particle size 50 μm) 32%; magnesium hydroxide (MH, average particle size 50 μm) 15%, ATH and MH combined 47%; quartz powder (average particle size 100 μm) 14%, without calcium carbonate; organically modified montmorillonite (OMMT, prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifier, single layer thickness 1.1 nm, aspect ratio not less than 100:1) 6%; ammonium polyphosphate (APP, crystal form II) 10%; anhydrous calcium borate ( 8%; the sum of the mass fractions of the above components is 100%. Additionally, the amount of initiator (methyl ethyl ketone peroxide, MEKP) is 0.5% of the resin mass; the amount of accelerator (cobalt naphthenate, calculated as 6% cobalt by mass) is 0.1% of the resin mass.

[0026] Step 2: Mixing to prepare a homogeneous slurry Add the resin, ATH, MH, quartz powder, OMMT, APP crystal form II, and anhydrous calcium borate weighed in step one to a mixing container, add the accelerator (cobalt naphthenate), and stir for 15 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; add the initiator (MEKP) just before pouring, stir for 5 minutes to make a homogeneous slurry; complete the pouring operation in step three within 30 minutes after adding the initiator; the initiator and accelerator must be added in steps and must not be directly mixed.

[0027] Step 3: Casting the gel to form a mold The homogeneous slurry is injected into the mold and left to stand at 25°C for 90 minutes. The slurry polymerizes and gels under the combined action of the initiator and accelerator. When the surface of the slurry does not stick when lightly touched with a finger and the product has a certain shape retention ability, the gelation is considered to be complete.

[0028] Step 4: Post-curing and demolding The gel product, along with the mold, is transferred to an oven and cured at 60°C for 2 hours to allow the resin to fully cross-link and cure. After curing, the product is removed and allowed to cool naturally to room temperature outside the oven before demolding, resulting in a durable and stain-resistant artificial stone product.

[0029] Example 4 This embodiment discloses a manufacturing process for a material that is resistant to breakage and staining, the process comprising the following steps: Step 1: Weigh each raw material component according to the formula mass fraction. Weigh the following components according to the total mass fraction of the formula for later use: isophthalic unsaturated polyester resin (viscosity 1200 mPa·s at 25℃, hereinafter referred to as "resin") 18%; aluminum hydroxide (ATH, average particle size 30 μm) 38%; magnesium hydroxide (MH, average particle size 30 μm) 10%, ATH and MH combined 48%; calcium carbonate (average particle size 50 μm) 15%, without quartz powder; organically modified montmorillonite (OMMT, prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifier, single layer thickness 1.1 nm, aspect ratio not less than 100:1) 5%; ammonium polyphosphate (APP, crystal form II) 7%; anhydrous calcium borate ( 7%; the sum of the mass fractions of the above components is 100%. Additionally, the amount of initiator (methyl ethyl ketone peroxide, MEKP) is 1.2% of the resin mass; the amount of accelerator (cobalt naphthenate, calculated as 6% cobalt by mass) is 0.3% of the resin mass.

[0030] Step 2: Mixing to prepare a homogeneous slurry Add the resin, ATH, MH, calcium carbonate, OMMT, APP crystal form II, and anhydrous calcium borate weighed in step one to a mixing container, add the accelerator (cobalt naphthenate), and stir for 25 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; add the initiator (MEKP) just before pouring, stir for 4 minutes to make a homogeneous slurry; complete the pouring operation in step three within 30 minutes after adding the initiator; the initiator and accelerator must be added in steps and must not be directly mixed.

[0031] Step 3: Casting the gel to form a mold The homogeneous slurry is injected into the mold and left to stand at 22°C for 75 minutes. The slurry polymerizes and gels under the combined action of the initiator and accelerator. When the surface of the slurry does not stick when lightly touched with a finger and the product has a certain shape retention ability, the gelation is considered to be complete.

[0032] Step 4: Post-curing and demolding The gel product, along with the mold, is transferred to an oven and cured at 65°C for 2 hours to allow the resin to fully cross-link and cure. After curing, the product is removed and allowed to cool naturally to room temperature outside the oven before demolding, resulting in a durable and stain-resistant artificial stone product.

[0033] Example 5 This embodiment discloses a manufacturing process for a material that is resistant to breakage and staining, the process comprising the following steps: Step 1: Weigh each raw material component according to the formula mass fraction. Weigh the following components according to their mass fractions according to the total formula: 20% isophthalic unsaturated polyester resin (viscosity 800 mPa·s at 25℃, hereinafter referred to as "resin"); 40% aluminum hydroxide (ATH, average particle size 20 μm) and 10% magnesium hydroxide (MH, average particle size 20 μm) in combination, totaling 50%; 6.7% quartz powder (average particle size 50 μm) and 3.3% calcium carbonate (average particle size 20 μm) in a mass ratio of 2:1, totaling 10%; 4% organically modified montmorillonite (OMMT); 8% ammonium polyphosphate (APP, crystal form II); and 8% anhydrous calcium borate (…). 8%; the sum of the mass fractions of the above components is 100%. Initiator and accelerator shall be weighed separately according to the following amounts for later use: initiator (methyl ethyl ketone peroxide, MEKP) shall be 1.0% of the resin mass; accelerator (cobalt naphthenate, calculated as 6% cobalt by mass) shall be 0.3% of the resin mass.

[0034] Step 2: Use ammonium polyphosphate (APP, crystal form II) as the low-temperature charring flame retardant component. This step uses ammonium polyphosphate (APP, crystal form II) as the low-temperature charring flame retardant component in the formulation. APP crystal form II has extremely low water solubility, approximately 0.5 g / 100 mL (25℃), about 100 times lower than diammonium hydrogen phosphate (solubility approximately 57.5 g / 100 mL, 25℃). In environments where washbasins are in prolonged contact with water, APP crystal form II particles do not dissolve in water due to their extremely low water solubility; phosphate ions do not dissolve from the particles and are not lost with water. The flame retardant effect of catalyzing charring on the resin surface at low temperatures remains stable throughout the entire service life of the product. APP crystal form II does not react prematurely with ATH particles during the room-temperature mixing stage of the formulation, resulting in good batch-to-batch repeatability of the flame retardant performance. During the combustion stage, when the temperature reaches approximately 200℃, APP decomposes to release phosphoric acid, catalyzing the charring of the resin surface and forming a charred solid layer on the product surface, preventing further heat conduction to the interior. Simultaneously, APP decomposes to release ammonia, which, together with the water vapor released from the decomposition of ATH / MH, dilutes the combustible gases in the combustion zone.

[0035] Step 3: Using anhydrous calcium borate ( As a high-temperature sealing and high-temperature mineralization flame retardant component This step uses anhydrous calcium borate ( Anhydrous calcium borate is used as a high-temperature flame-retardant component in the formulation. It contains no water of crystallization and does not release moisture throughout the entire post-curing temperature range (60–120°C). Therefore, the product surface does not develop bubbles or pores due to water vapor escape. The anti-fouling effect of the OMMT sheet filling the surface micropores is no longer offset by pores; both work synergistically to reduce the open porosity of the product surface. Anhydrous calcium borate does not contain… The ions do not compete with the resin curing accelerator (cobalt naphthenate) for complexation during the mixing and curing stages, ensuring that the resin's gel time remains consistent across production batches. Under high-temperature conditions (>700℃), anhydrous calcium borate softens upon heating, forming a uniformly distributed calcium borosilicate glass phase that blocks the escape channels of flammable gases from the surface of product residues; the calcium component (as...) (Calculated) is released in an active state, reacting with the products generated by the decomposition of ATH. A solid-state reaction occurs, producing calcium aluminate ( The generated calcium aluminate, together with the high-temperature mineral residues of the montmorillonite silica-alumina framework in OMMT, forms a multi-element inorganic mineralization protective layer, which enables the product to maintain its shape integrity under the continuous action of high-temperature flame.

[0036] Step 4: Add organically modified montmorillonite (OMMT) Organically modified montmorillonite (OMMT) is added to the formulation at a mass fraction of 4%, uniformly dispersed in an unsaturated polyester resin matrix as ultrafine sheets. OMMT is prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifiers, with a single layer thickness of approximately 1 nm and an aspect ratio exceeding 100:1. After curing, the high aspect ratio sheets of OMMT fill the fine pore channels that particulate fillers (ATH / MH, average particle size 20 μm) cannot fill during stacking, reducing the open porosity of the product surface and near-surface areas, thus improving antifouling performance. The OMMT sheets deflect crack propagation paths, helping to reduce product breakage rates. Simultaneously, the OMMT sheets form a layered barrier structure within the matrix, slowing the rate of flammable gas escape from the product interior to the exterior during combustion, synergistically enhancing the flame retardant effect in the mid-temperature range.

[0037] Step 5: Replace part of the ATH / MH in the formulation with quartz powder and calcium carbonate as structural fillers. Quartz powder (average particle size 50 μm) and calcium carbonate (average particle size 20 μm) were combined at a mass ratio of 2:1, totaling 10% of the formulation, replacing an equal amount of ATH / MH. With the total filler content remaining essentially unchanged, the absolute amount of ATH / MH was reduced, alleviating the problems of decreased matrix toughness and increased brittleness caused by excessive ATH / MH introduction. Calcium carbonate (Mohs hardness approximately 3) has a lower hardness than quartz powder (Mohs hardness approximately 7), and the combination of the two helps to reduce the overall brittleness of the product.

[0038] Step 6: After mixing all components and the accelerator evenly, add the initiator to prepare a homogeneous slurry. Add the resin, ATH / MH, quartz powder, calcium carbonate, OMMT, APP crystal form II, and anhydrous calcium borate weighed in step one to a mixing container. Add the accelerator (cobalt naphthenate) and stir for 20 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration. Just before casting, add the initiator (methyl ethyl ketone peroxide, MEKP) and stir for 4 minutes to prepare a homogeneous slurry with uniform dispersion of all components. Complete the casting operation in step seven within 30 minutes after adding the initiator. The initiator and accelerator must be added in steps and must not be directly mixed to prevent premature initiation of the polymerization reaction.

[0039] Step 7: Pour the homogeneous slurry into the mold and let it stand at room temperature until it gels and sets. The homogeneous slurry is injected into the mold and left to stand at room temperature (23°C) for 60 minutes. Under the combined action of the initiator and accelerator, the slurry undergoes a polymerization reaction and gradually gels and solidifies. When the surface of the slurry does not stick to the touch and the product has a certain shape retention ability, the gelation process is considered complete.

[0040] Step 8: Perform post-curing treatment on the gel product, and demold to obtain the product. After gel molding is completed, the product along with the mold is transferred to an oven and cured at 70°C for 1.5 hours to allow the resin to fully cross-link and cure. After curing, the product is removed and allowed to cool naturally to room temperature outside the oven before demolding to obtain a durable and stain-resistant artificial stone product.

[0041] Experimental verification Experiment 1: Verification of Open Porosity and Antifouling Performance of Product Surface 1. Experimental Objective This experiment aims to verify the synergistic effect of organically modified montmorillonite (OMMT) and anhydrous calcium borate on reducing the open porosity of the product surface and improving its antifouling performance. The traditional formulation containing water-soluble zinc borate (without OMMT, hereinafter referred to as Comparative Sample A) and the formulation that only introduces OMMT but still uses zinc borate (hereinafter referred to as Comparative Sample B) are compared with Example 2.

[0042] 2. Preparation of experimental samples Three groups of samples were prepared, and the formulations of each group are shown in Table 1. The preparation process was carried out according to the following parameters: each solid component was mixed with resin and accelerator (cobalt naphthenate, cobalt content 6%, amount is 0.3% of resin mass) and stirred for 20 min. Initiator (MEKP, amount is 1.0% of resin mass) was added and stirred for 4 min. The mixture was then poured immediately and allowed to stand at 23℃ for 60 min to gel. The mixture was then transferred to an oven and cured at 70℃ for 1.5 h. After naturally cooling to room temperature, the mixture was demolded to obtain a flat plate sample with dimensions of 150 mm × 150 mm × 10 mm.

[0043] Table 1. Sample formulations for each group in Experiment 1 (mass fraction, %) 3. Experimental conditions (1) Surface open porosity: Mercury intrusion porosimetry (MIP) was used to analyze the pore size range of 0.1–100 μm (based on the Washburn equation). mercury surface tension N / m, contact angle The corresponding instrument mercury inlet pressure range is approximately 0.012–12 MPa. The average value of three samples from each group (cut into 10 mm × 10 mm × 5 mm pieces, with only the surface to 2 mm depth area taken) is calculated.

[0044] (2) Anti-fouling performance: After the sample surface was uniformly sanded with 320-grit sandpaper, 10 μL each of soy sauce, olive oil and red wine were added. The sample was left to stand in water for 24 h, rinsed with water and dried at 60℃ for 30 min. The color difference before and after cleaning was measured with a spectrophotometer. ; Convert the pollution prevention rating (out of 5 points) according to the following standards: 5 points 4 points 3 points 2 points 1 point; calculate the average score of the three stains, and take the average of 5 samples in each group.

[0045] 4. Experimental Procedure (1) Weigh each component according to the formula in Table 1, and prepare each group of flat plate samples according to the above process, with 5 samples in each group.

[0046] (2) Cut the sample into small pieces of 10 mm × 10 mm × 5 mm for MIP test. Take 3 pieces in each group, measure the surface open porosity and take the average value.

[0047] (3) The surface of the complete flat plate sample was evenly sanded with 320-grit sandpaper, wiped with anhydrous ethanol and dried; three kinds of stains were dripped on each sample and left to stand for 24 hours, then rinsed with water and dried. The color difference was measured with a spectrophotometer. The anti-fouling rating was then calculated, and the average of the five samples in each group was taken.

[0048] 5. Experimental Results Table 2 Test results of open porosity and antifouling rating of product surface Figure 1 and Figure 2 The following are bar charts comparing the surface open porosity and antifouling rating of the three groups of samples.

[0049] Figure 3 This is a comparison image of the cross-section of Example 2 and Comparative Sample A using scanning electron microscopy (SEM).

[0050] 6. Analysis and Summary From Table 2 and Figure 1 and Figure 2 It can be seen that the open porosity of the surface of the comparative sample A is the highest (3.82%), and the anti-fouling rating is only 2.3 points, indicating that the surface of traditional zinc borate formulation products containing water of crystallization has more pores and the path of stain penetration is unobstructed.

[0051] After the introduction of OMMT (comparison sample B), the porosity decreased to 2.76% and the antifouling rating increased to 3.2 points, indicating that the high aspect ratio OMMT sheets have a filling effect on the pores between particles; however, the premature release of zinc borate crystal water in the post-curing stage still leaves pores, which limits the further reduction of porosity.

[0052] Replacing zinc borate with anhydrous calcium borate while retaining OMMT (Example 2) reduced the porosity to 1.43%, a 62.6% decrease compared to control sample A, and improved the antifouling rating to 4.6 points. Experiments demonstrate that eliminating the source of pores during the curing stage and the physical sealing effect of OMMT work synergistically to achieve a key technological combination for durable antifouling of the product.

[0053] Experiment 2: Limiting Oxygen Index and Vertical Combustion Rating Test 1. Experimental Objective This experiment aims to verify the improvement effect of the formulation of the present invention (with APP crystal form II, anhydrous calcium borate, and OMMT synergistic flame retardant) on combustion performance compared with the traditional flame retardant formulation (diammonium hydrogen phosphate and zinc borate, without OMMT). The limiting oxygen index (LOI), vertical burning rating (UL-94), and peak heat release rate (PHRR) were used as evaluation indicators to test Examples 2 and 3, and compared with control sample A.

[0054] 2. Preparation of experimental samples The formulation of control sample A is shown in Table 1 (Experiment 1), and the formulations of Examples 2 and 3 are shown in Examples 2 and 3 of this paper, respectively. Standard specimens for each group were prepared according to the following process: LOI specimen: A 100 mm × 10 mm × 4 mm strip was prepared by casting. After gel molding according to the corresponding process parameters of the example, it was post-cured at 70℃ (comparative sample A) or the temperature specified in each example, and then cooled and demolded.

[0055] UL-94 specimens: 125 mm × 13 mm × 3.2 mm strips were prepared by casting, with the same process parameters as above.

[0056] Cone calorimeter specimen: A 100 mm × 100 mm × 4 mm plate was prepared by casting, with the same process parameters as above.

[0057] Five pieces of each specification were prepared for each group.

[0058] 3. Experimental conditions (1) Limiting oxygen index: According to ISO 4589-2, the minimum oxygen concentration required to maintain the combustion of the sample is determined by the change in the volume ratio of oxygen to nitrogen. The average value of 5 samples in each group is taken and the result is accurate to 0.1%.

[0059] (2) Vertical flammability rating: According to UL-94, the flammability rating is determined by 10 s flame contact, observation of self-extinguishing time and ignition of dripping material (V-0 is the best, followed by V-1, V-2 and HB).

[0060] (3) Peak heat release rate: According to ISO 5660-1, radiative heat flux 50 kW / m 2 Record the heat release rate as a function of time, and take the peak value PHRR (kW / m²). 2 ) and total heat release (THR) (MJ / m 2 ).

[0061] 4. Experimental Procedure (1) Prepare the above three types of test specimens according to the formula of each group, with 5 specimens in each group, and mark them with numbers.

[0062] (2) Each specimen was conditioned for 48 hours at a temperature of 23℃ and a humidity of 50% before being tested.

[0063] (3) Complete the LOI test, UL-94 test and cone calorimeter test in sequence, record the various indicators, and take the average value of each group.

[0064] 5. Experimental Results Table 3 Combustion performance test results Figure 4 and Figure 5 A bar chart comparing the limiting oxygen index and peak heat release rate for each sample.

[0065] 6. Analysis and Summary From Table 3 and Figure 4 and Figure 5 It can be seen that the LOI of the comparison sample A is only 28.4%, the UL-94 rating is HB, and the peak heat release rate is as high as 285 kW / m. 2 It has relatively weak flame retardant properties.

[0066] Example 2 (APP crystal form II plus anhydrous calcium borate plus OMMT) LOI increased to 36.1%, UL-94 reached V-0 level, PHRR decreased by 50.2%, and THR decreased by 38.3%; Example 3 (higher dosage of each flame retardant component) LOI further increased to 37.8%, and PHRR decreased by 55.1%.

[0067] Experiments have shown that the segmented synergistic flame retardant mechanism of APP crystal form II, ATH / MH, OMMT and anhydrous calcium borate effectively exerts itself at various stages from low temperature to high temperature, resulting in a significant improvement in the flame retardant performance of the product, reaching the V-0 flame retardant level.

[0068] Experiment 3: Verification of the long-term stability of flame retardant performance after water immersion 1. Experimental Objective This experiment aims to verify the contribution of the low water solubility of ammonium polyphosphate (APP, crystal form II) to the long-term flame retardant stability. Using a formulation containing diammonium hydrogen phosphate (a highly water-soluble, low-temperature char-forming component) as a comparison, the experiment simulates the long-term water contact environment of a washbasin. The LOI was measured after water immersion treatment for different durations to compare the decay trend of the flame retardant performance of the two formulations over time.

[0069] 2. Preparation of experimental samples Two sets of samples were prepared, and the formulations are shown in Table 4. The only difference between control sample C and Example 2 is the selection of the low-temperature charring component; all other components and process parameters are completely identical to ensure that the comparison variables are unique.

[0070] Table 4. Sample formulations (mass fraction, %) for each group in Experiment 3 Both groups prepared LOI standard specimens (100 mm × 10 mm × 4 mm) according to the following process: the accelerator (cobalt naphthenate, cobalt content 6%, amount is 0.3% of resin mass) was mixed with each solid component and stirred for 20 min, the initiator (MEKP, amount is 1.0% of resin mass) was added and stirred for 4 min, then poured, allowed to stand at 23℃ for 60 min to gel, cured at 70℃ for 1.5 h, and demolded after natural cooling. 25 specimens were prepared in each group.

[0071] 3. Experimental conditions Immersion medium: deionized water, room temperature (23 ± 2℃), the amount of water in the immersion container should be enough to completely submerge the specimen.

[0072] Soaking time: 0 days (baseline value without soaking), 30 days, 90 days, 180 days, a total of 4 time points, with 5 pieces per group for each time point.

[0073] LOI test: After the corresponding soaking period is completed, the specimens are taken out and dried in an oven at 60℃ for 24 h to remove surface adsorbed water. After conditioning at 23℃ and 50% relative humidity for 4 h, the LOI test is completed according to ISO 4589-2. The average value of 5 specimens in each group is taken.

[0074] 4. Experimental Procedure (1) Prepare LOI specimens for each group according to the formula in Table 4, with 25 specimens in each group, and label the soaking time number respectively.

[0075] (2) Soak each group of specimens in deionized water in batches according to the soaking time, and ensure that each batch is taken out 48 hours before the target test date.

[0076] (3) After taking it out, dry it in an oven at 60℃ for 24 h, and adjust it at 23℃ and 50% humidity for 4 h. Measure the LOI value according to ISO 4589-2. Take the average value of 5 pieces in each batch and calculate the LOI change rate of each time point compared with the baseline value of 0 days.

[0077] 5. Experimental Results Table 5. Results of LOI variation over time after water immersion Figure 6 This is a line graph showing the change of LOI over time after immersion in water.

[0078] 6. Analysis and Summary From Table 5 and Figure 6 It can be seen that the LOI of the control sample C (diammonium hydrogen phosphate) was 30.2% when it was not soaked, and dropped to 24.0% after soaking for 180 days, a cumulative decrease of 20.5%, which is lower than the flame retardant reference benchmark (27%). This indicates that the water-soluble diammonium hydrogen phosphate continues to dissolve as water penetrates, and its low-temperature charring flame retardant effect gradually decreases year by year, making its long-term fire safety unreliable.

[0079] Example 2 (APP crystal form II): After 180 days of immersion, the LOI only decreased from 36.1% to 35.7%, with a change rate of only 1.1%. The flame retardant performance is almost unaffected by the water environment, proving that the extremely low water solubility of APP crystal form II does not dissolve or leak in the long-term water environment, and can ensure the flame retardant durability of the product throughout its entire service life.

[0080] Experiment 4: Impact Strength and Bending Strength Test 1. Experimental Objective This experiment aims to verify the effect of replacing part of ATH / MH with quartz powder / calcium carbonate and introducing OMMT on the improved mechanical properties of the product after breakage. The traditional formulation with high ATH / MH filling (without structural filler and without OMMT, hereinafter referred to as control sample D) was used as the control, and Examples 1 and 2 were used as experimental samples to evaluate the changes in Charpy notched impact strength and flexural strength.

[0081] 2. Preparation of experimental samples Comparative sample D is a traditional high ATH / MH formulation (ATH and MH combined is 65%, which is beyond the scope of this invention) representing the brittleness problem of existing artificial stone formulations. Examples 1 and 2 are the formulations of this invention. The formulations of each group are shown in Table 6.

[0082] Table 6. Sample formulations (mass fraction, %) for each group in Experiment 4 Each group's casting process was performed according to its specified parameters: Control sample D was allowed to gel at 23℃ for 60 min and then cured at 70℃ for 1.5 h; Example 1 was allowed to gel at 20℃ for 30 min and then cured at 80℃ for 1 h; Example 2 was allowed to gel at 23℃ for 60 min and then cured at 70℃ for 1.5 h. All groups were demolded after naturally cooling to room temperature outside the oven. Charpy notched impact specimens (80 mm × 10 mm × 4 mm, single-sided V-notch depth 2 mm, notch radius 0.25 mm) and bending specimens (80 mm × 10 mm × 4 mm) were prepared, with 10 specimens of each specification per group.

[0083] 3. Experimental conditions (1) Charpy notch impact strength: According to ISO 179-1, the pendulum energy is 1 J (based on the estimated impact strength of this group of samples, it is 2-7 kJ / m). 2 The net cross-sectional area of ​​the sample is 32 mm. 2 The estimated absorbed energy is 64–224 mJ, accounting for 6.4%–22.4% of the pendulum's capacity, which meets the ISO 179-1 recommendation that the absorbed energy should be within 10%–80% of the pendulum's capacity. The span is 62 mm, and the notch faces away from the pendulum. Calculate the impact strength (kJ / m). 2 Each group contains 10 items, and the average of the 8 items is taken after removing the highest and lowest outliers.

[0084] (2) Bending strength and bending modulus: According to ISO 178, the span is 64 mm, the loading speed is 2 mm / min, the failure load is recorded, and the bending strength (MPa) and bending modulus (GPa) are calculated. The average value is taken for each group of 10 pieces.

[0085] (3) Test environment: temperature 23 ± 2℃, relative humidity 50 ± 5%; the specimens were conditioned in this environment for 48 h before testing.

[0086] 4. Experimental Procedure (1) Prepare standard test specimens for each group according to the formula in Table 6, with 10 specimens for each specification in each group, and adjust them at 23℃ and 50% humidity for 48h.

[0087] (2) Perform Charpy notch impact test according to ISO 179-1, record the impact strength of each piece, and take the average of 8 pieces after removing the maximum and minimum outliers in each group.

[0088] (3) Perform three-point bending tests according to ISO 178, record the failure load for each piece, calculate the bending strength and bending modulus, and take the average value of 10 pieces in each group.

[0089] 5. Experimental Results Table 7 Impact strength and flexural strength test results Figure 7 Grouped bar charts comparing Charpy notched impact strength and flexural strength of each group of samples.

[0090] 6. Analysis and Summary From Table 7 and Figure 7 It can be seen that the Charpy notched impact strength of the control sample D (65% ATH / MH total, no structural filler, no OMMT) is only 2.8 kJ / m. 2 The flexural strength was 45.2 MPa, but the product exhibited significant brittleness. Introducing calcium carbonate structural filler and a small amount of OMMT (Example 1, ATH used alone, ATH / MH total 50%) increased the impact strength to 5.1 kJ / m². 2 The flexural strength was increased to 58.4 MPa, representing increases of 82.1% and 29.2% compared to the control sample D, respectively. Based on this, by using a combination of quartz powder and calcium carbonate and appropriately increasing the amount of OMMT (Example 2, ATH / MH total 50%), the impact strength reached 6.3 kJ / m. 2 The bending strength reached 67.1 MPa, which was 125.0% and 48.5% higher than that of the control sample D, respectively. The bending modulus remained at 9.0 GPa (the difference from the control sample D was no more than 9%, indicating that the stiffness was not significantly affected).

[0091] Experiments have shown that replacing part of the ATH / MH with structural filler can effectively reduce matrix brittleness, and the high aspect ratio lamellars of OMMT further improve the impact resistance of the product by deflecting crack propagation. The synergy of the two is an effective means of improving the fracture resistance of the present invention.

[0092] The embodiments of the present invention have been described above. However, the embodiments are not limited to the specific implementation methods described above. The specific implementation methods described above are merely illustrative and not restrictive. Those skilled in the art can make more equivalent embodiments under the guidance of the present embodiments, and all of them are within the protection scope of the present embodiments.

Claims

1. A manufacturing process for a material that is resistant to breakage and staining, wherein the material is prepared by casting and post-curing using unsaturated polyester resin as a matrix and halogen-free flame-retardant fillers and mineral fillers as fillers, characterized in that... Weigh the following raw materials according to the total mass fraction of the formula: Unsaturated polyester resin 15-25%, aluminum hydroxide 45-60% or a combination of aluminum hydroxide 30-50% and magnesium hydroxide 5-15% (total aluminum hydroxide and magnesium hydroxide 45-60%), quartz powder and / or calcium carbonate 5-15% total, organically modified montmorillonite 2-6%, ammonium polyphosphate crystal form II 3-10%, anhydrous calcium borate ( 2-8%; Separately, use methyl ethyl ketone peroxide as an initiator, at a dosage of 0.5% to 2.0% of the resin mass, and cobalt naphthenate as an accelerator, at a dosage of 0.1% to 0.5% of the resin mass; After uniformly mixing the above solid components with resin and accelerator, an initiator is added to form a homogeneous slurry. The slurry is poured into a mold and allowed to stand at 20-25°C to gel and form. The product is then kept at 60-80°C for 1-2 hours to cure. After demolding, the material is obtained.

2. The manufacturing process according to claim 1, characterized in that, The unsaturated polyester resin is an orthophthalic or isophthalic unsaturated polyester resin with a viscosity of 500–1500 mPa·s at 25°C.

3. The manufacturing process according to claim 1, characterized in that, The average particle size of the aluminum hydroxide is 5–50 μm.

4. The manufacturing process according to claim 1 or 3, characterized in that, The formula contains magnesium hydroxide, which accounts for 5-15% of the total mass of the formula, and the average particle size of magnesium hydroxide is 5-50 μm. At this time, the amount of aluminum hydroxide accounts for 30-50% of the total mass of the formula, and the total amount of aluminum hydroxide and magnesium hydroxide accounts for 45-60% of the total mass of the formula.

5. The manufacturing process according to claim 1, characterized in that, The average particle size of the quartz powder is 10–100 μm, and the average particle size of the calcium carbonate is 5–50 μm; when the quartz powder and calcium carbonate are used simultaneously, their mass ratio is 1:1 to 3:

1.

6. The manufacturing process according to claim 1, characterized in that, The organically modified montmorillonite is prepared by intercalation modification of montmorillonite with long-chain alkyl quaternary ammonium salt organic modifiers, and its monolayer thickness is 0.9-1.1 nm with an aspect ratio of not less than 100:

1.

7. The manufacturing process according to claim 1, characterized in that, The accelerator, cobalt naphthenate, is calculated as 6% by mass of cobalt.

8. The manufacturing process according to claim 1, characterized in that, The mixing steps are as follows: each solid component, resin and accelerator are put into a mixing container and stirred for 15 to 30 minutes until the slurry has a uniform appearance and no obvious color unevenness or coarse particle agglomeration; the initiator is added just before pouring and stirred for 3 to 5 minutes; and the pouring operation is completed within 30 minutes after the initiator is added; the initiator and accelerator must be added in steps and the two must not be mixed directly.

9. The manufacturing process according to claim 1, characterized in that, The casting and molding step is as follows: after injecting the homogeneous slurry into the mold, let it stand at 20-25℃ for 30-90 minutes. When the surface of the slurry does not stick when lightly touched with a finger and the product has a certain shape retention ability, it is considered that the gel molding is completed. The post-curing step is as follows: keep the gel product together with the mold at 60-80℃ for 1-2 hours. After the post-curing is completed, cool it to room temperature and then demold.

10. A material that is resistant to breakage and staining, characterized in that, The material is used to prepare artificial stone products, the composition of which by mass fraction includes: 15-25% cured unsaturated polyester resin, 45-60% aluminum hydroxide or a combination of 30-50% aluminum hydroxide and 5-15% magnesium hydroxide, 5-15% quartz powder and / or calcium carbonate, 2-6% organic modified montmorillonite, 3-10% ammonium polyphosphate crystal form II and 2-8% anhydrous calcium borate.

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