Preparation method of chemical-resistant, high-transparency and low-haze polymethyl methacrylate resin composition

Abstract

The invention relates to the technical field of high polymer materials, in particular to a preparation method of a chemical-resistant, high-transparency and low-haze polymethyl methacrylate resin composition, which comprises the following steps: firstly, preparing phenyl-acryloyloxy organic silicon emulsion, then adding an emulsifier, an initiator and a mixed monomer containing acrylate and a grafting cross-linking agent, and uniformly stirring to obtain the chemical-resistant, high-transparency and low-haze polymethyl methacrylate resin composition. The preparation method comprises the following steps: preparing phenyl-acryloyloxy organic silicon modified acrylate copolymer emulsion, and then adding an initiator and methyl methacrylate to prepare phenyl-acryloyloxy organic silicon / acrylate / methyl methacrylate grafted copolymer emulsion.

Description

A method for preparing a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition. Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a method for preparing a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition. Background Technology

[0002] Polymethyl methacrylate (PMMA) resin is widely used in industry due to its excellent transparency, appearance, weather resistance, gloss, and processability. However, its poor impact resistance and chemical resistance limit its application in certain special environments. Most improvement methods focus on enhancing its impact resistance, with few mature solutions for improving its chemical resistance. Furthermore, existing methods for improving impact resistance can negatively impact transparency and haze to some extent.

[0003] A common method to improve the impact resistance of polymethyl methacrylate (PMMA) resin is to add a core-shell toughening agent. Upon impact, the rubber core absorbs energy, inducing crazing or voiding, thus increasing the material's impact strength. The shell layer increases compatibility. The particle size of the core-shell toughening agent and the refractive indices of the core and shell layers are key factors affecting the transparency and haze of PMMA resin. Smaller particle sizes have a lower impact on the transparency and haze of PMMA resin, but a weaker effect on improving impact resistance. The closer the refractive indices of the core and shell layers are to those of PMMA resin, the lower their impact on the transparency and haze of PMMA resin. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition, thereby solving the technical problem that existing methods for improving impact performance may, to some extent, affect transparency and haze.

[0005] This invention discloses a method for preparing a toughening agent, comprising the following steps: first, a phenyl-acryloyloxy silicone emulsion is prepared; then, an emulsifier, an initiator, a mixed monomer containing acrylate and a grafting crosslinking agent is added to prepare a phenyl-acryloyloxy silicone-modified acrylate copolymer emulsion; then, an initiator and methyl methacrylate are added to prepare a phenyl-acryloyloxy silicone / acrylate / methyl methacrylate graft copolymer emulsion.

[0006] Furthermore, the method for preparing the phenyl-acryloyloxy silicone emulsion involves stirring phenylsilane, acryloyloxysilane, deionized water, and emulsifier, heating the mixture, adding a catalyst, cooling the solid-liquid reaction mixture, and adjusting the pH to 6-8 to obtain the phenyl-acryloyloxy silicone emulsion.

[0007] Furthermore, the weight ratio of the phenylsilane, acryloxysilane, deionized water, emulsifier, and catalyst is 5-20:1-5:200-300:0.5-1:0.5-1; and / or, the phenylsilane is any one or more of trimethoxyphenylsilane, methylphenyldimethoxysilane, triethoxyphenylsilane, or methylphenyldiethoxysilane; and / or, the acryloxysilane is at least one of γ-methacryloyloxypropyltrimethoxysilane or γ-methacryloyloxypropylmethyldimethoxysilane; and / or, the catalyst is at least one of hydrochloric acid, sulfuric acid, or phosphoric acid.

[0008] Further, the weight ratio of the phenyl-acryloyloxy silicone emulsion, emulsifier, initiator, and mixed monomers containing acrylate and graft crosslinking agent is: 207-307:0.5-1:0.1-0.5:40-60:0.5-1; and / or, the acrylate is any one or more of ethyl acrylate, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, isobornyl methacrylate, phenyl methacrylate, or benzyl methacrylate; and / or, the graft crosslinking agent is any one or more of allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl itaconic acid, monoallyl maleate, or monoallyl fumarate.

[0009] Furthermore, the weight ratio of the phenyl-acryloyloxysilicone modified acrylate copolymer emulsion, the initiator, and methyl methacrylate is 248.1-369.5: 0.1-0.5: 30-50.

[0010] Furthermore, the emulsifier is any one or more of anionic surfactants.

[0011] Furthermore, the emulsifier is any one or more of alkylbenzene sulfonates, α-olefin sulfonates, alkyl sulfonates, α-sulfonyl monocarboxylic acids, fatty acid sulfonyl esters, succinate sulfonates, alkylnaphthalene sulfonates, petroleum sulfonates, lignin sulfonates, or alkyl glycerol ether sulfonates.

[0012] Furthermore, the initiator is any one or more of inorganic peroxide compounds.

[0013] Furthermore, the initiator is any one or more of potassium persulfate, sodium persulfate, or ammonium persulfate.

[0014] A toughening agent prepared using the method described above.

[0015] The application of a toughening agent in polymethyl methacrylate resin.

[0016] A method for preparing a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition, comprising the use of the aforementioned toughening agent.

[0017] Further, the phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion is heated, a demulsifier is added, and the reaction continues. After filtration, washing, and drying, phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer powder is obtained.

[0018] Furthermore, the demulsifier comprises water and a demulsifier; and / or, the weight ratio of the phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion to the demulsifier is 1:1; further, the demulsifier is any one or more of magnesium sulfate or calcium chloride, and the weight ratio of the demulsifier in the demulsifier is 2%.

[0019] A chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition having the aforementioned toughening agent.

[0020] Compared with the prior art, the beneficial effects of this invention are as follows: 1. This invention synthesizes a phenyl-acryloyloxy oligomer-modified acrylate rubber, and grafts methyl methacrylate onto its surface as a core, thus synthesizing a phenyl-acryloyloxy oligomer-modified acrylate rubber / methyl methacrylate core-shell graft copolymer. This copolymer is then mixed with polymethyl methacrylate resin and melt-extruded to prepare a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition. By adjusting the refractive index of the acrylate to a level similar to PMMA (1.49) using the phenyl-acryloyloxy oligomer, its application in polymethyl methacrylate resin can significantly improve the impact resistance of the polymethyl methacrylate resin without sacrificing its original high transparency and low haze. Simultaneously, the introduction of phenyl silicone rubber can greatly improve the chemical resistance of PMMA products, showing broad application prospects.

[0021] 2. Using phenyl-acryloyloxy oligomer-modified acrylate rubber as the core can effectively improve the impact resistance and chemical resistance of the product. At the same time, its refractive index is consistent with that of polymethyl methacrylate resin, which can ensure that when it is used in polymethyl methacrylate resin, it will not lose its original high transparency and low haze. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0023] Example 1 This example discloses a method for preparing core-shell structure modified ceramic powder, including the following steps: Step 1: Stir 5g of methylphenyldimethoxysilane, 1g of γ-methacryloyloxypropylmethyldimethoxysilane, 250g of deionized water, and 0.5g of sodium dodecyl sulfate, heat to 75°C, add 1g of 10% sulfuric acid, continue to react at this temperature for 8 hours, cool to 30°C, and adjust the pH (with 10% sodium hydroxide aqueous solution) to 7 to obtain phenyl-acryloyloxy organosilicon emulsion.

[0024] Step 2: Heat the phenyl-acryloyloxy silicone emulsion to 75°C, add 0.5g sodium dodecyl sulfate and 0.2g potassium persulfate, and dropwise add 40g butyl acrylate and 0.5g allyl methacrylate (the addition is completed within 2 hours). After the addition is completed, continue to keep the reaction at the temperature for 2 hours to obtain the phenyl-acryloyloxy silicone modified acrylate copolymer emulsion.

[0025] Step 3: Heat the phenyl-acryloyloxy silicone-modified acrylate copolymer emulsion to 75°C, add 0.2g of potassium persulfate, and dropwise add 60g of methyl methacrylate (complete the dropwise addition within 2 hours). After the dropwise addition is completed, continue to keep the reaction at the temperature for 2 hours to obtain a phenyl-acryloyloxy silicone / acrylate / methyl methacrylate graft copolymer emulsion with a particle size D50 of 158nm.

[0026] Step 4: Heat the phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion to 60°C, add demulsifier and water to prepare the demulsifier, continue to keep the reaction at the temperature for 1 hour, filter, wash and dry to obtain phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer powder toughening agent ①.

[0027] Step 5: The phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer powder was mixed with polymethyl methacrylate resin at a weight ratio of 20:100 and then melt-extruded by a twin-screw extruder to obtain a polymethyl methacrylate composition.

[0028] Example 2: Based on Example 1, the "1g sodium dodecyl sulfate" in step 1 was changed to "0.75g sodium dodecyl sulfate", and the other formulations and processes were the same as in Example 1, to obtain toughening agent ②, wherein the particle size D50 of the obtained phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion was 169nm.

[0029] Example 3: Based on Example 1, the "1g sodium dodecyl sulfate" in step 1 was changed to "0.5g sodium dodecyl sulfate", and the other formulations and processes were the same as in Example 1, to obtain toughening agent ③, wherein the particle size D50 of the obtained phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion was 183nm.

[0030] Example 4: Based on Example 1, the "5g methylphenyldimethoxysilane, 1g γ-methacryloyloxypropylmethyldimethoxysilane" in step 1 was changed to "6.25g methylphenyldimethoxysilane, 1.25g γ-methacryloyloxypropylmethyldimethoxysilane"; the "0.2g potassium persulfate, 40g butyl acrylate, 0.5g allyl methacrylate" in step 2 was changed to "0.25g potassium persulfate, 50g butyl acrylate, 0.625g allyl methacrylate". Other formulations and processes were the same as in Example 1, and toughening agent ④ was obtained.

[0031] Example 5: Based on Example 1, the "5g methylphenyldimethoxysilane, 1g γ-methacryloyloxypropylmethyldimethoxysilane" in step 1 was changed to "7.5g methylphenyldimethoxysilane, 1.5g γ-methacryloyloxypropylmethyldimethoxysilane"; the "0.2g potassium persulfate, 40g butyl acrylate, 0.5g allyl methacrylate" in step 2 was changed to "0.3g potassium persulfate, 60g butyl acrylate, 0.75g allyl methacrylate". The other formulations and processes were the same as in Example 1, and toughening agent ⑤ was obtained.

[0032] Comparative Example 1: Commercially available PMMA toughening agent (Kaneyuki M210) and commercially available conventional polymethyl methacrylate resin PMMA (Mitsubishi Rayon VH001) samples.

[0033] Samples were prepared using commercially available conventional polymethyl methacrylate resin PMMA (Mitsubishi Rayon VH001) and a chemically resistant, highly transparent, and low-haze toughening agent synthesized in the examples. Their impact properties, light transmittance, haze, and alcohol resistance were tested. The comparative examples were samples prepared using commercially available PMMA toughening agent (Kanebuchi M210) and PMMA.

[0034] Table 1 Performance Comparison Table

[0035] Note: Notched impact test was conducted according to the method recorded in GB / T 1843, where the chemical resistance test was conducted by immersion in 50% ethanol for 48 hours; transmittance and haze were determined according to the method recorded in GB / T 2410-2008.

[0036] As shown in the table above, the samples prepared using the flame-retardant toughening agent of the present invention (Examples 1, 2, and 3) showed that as the amount of emulsifier decreased, the particle size of the synthesized toughening agent increased, the impact strength of the prepared polymethyl methacrylate resin increased, the light transmittance decreased slightly, and the haze increased slightly. However, as the glue content increased (Examples 1, 4, and 5), the impact strength of the prepared polymethyl methacrylate resin increased, while the effects on light transmittance and haze were not significant. This indicates that the core layer rubber has a similar effect on the light transmittance and haze of the polymethyl methacrylate resin, with both having refractive indices at essentially the same level.

[0037] Compared with the comparative examples, it was found that the toughening agent prepared in this invention can effectively improve the impact resistance and chemical resistance of polymethyl methacrylate resin while having little impact on transparency and haze. In contrast (Examples 1, 4, and 5), it was found that the chemical resistance increased with the increase of phenyl content.

[0038] The above are the embodiments listed in this example. However, this example is not limited to the optional embodiments described above. Those skilled in the art can arbitrarily combine the above methods to obtain other various embodiments. Anyone can derive other various forms of embodiments based on the inspiration of this example. The above specific embodiments should not be construed as limiting the scope of protection of this example. The scope of protection of this example should be determined by the claims, and the specification can be used to interpret the claims.

Claims

1. A method for preparing self-healing thermally conductive silicone rubber for connectors, characterized in that: The process includes the following steps: first, a phenyl-acryloyloxy silicone emulsion is prepared; then, a mixture of emulsifiers, initiators, acrylate-containing and graft crosslinking agents is added to prepare a phenyl-acryloyloxy silicone-modified acrylate copolymer emulsion; finally, an initiator and methyl methacrylate are added to prepare a phenyl-acryloyloxy silicone / acrylate / methyl methacrylate graft copolymer emulsion.

2. The method for preparing a self-healing thermally conductive silicone rubber for connectors according to claim 1, characterized in that: The method for preparing the phenyl-acryloyloxy silicone emulsion is as follows: phenylsilane, acryloxysilane, deionized water, and emulsifier are stirred, heated, and then a catalyst is added. The reaction solid and liquid are cooled, and the pH is adjusted to 6-8 to obtain the phenyl-acryloyloxy silicone emulsion.

3. The method for preparing a self-healing thermally conductive silicone rubber for connectors according to claim 2, characterized in that: The weight ratio of the phenylsilane, acryloxysilane, deionized water, emulsifier, and catalyst is 5-20:1-5:200-300:0.5-1:0.5-1; and / or, the phenylsilane is any one or more of trimethoxyphenylsilane, methylphenyldimethoxysilane, triethoxyphenylsilane, or methylphenyldiethoxysilane; and / or, the acryloxysilane is at least one of γ-methacryloyloxypropyltrimethoxysilane or γ-methacryloyloxypropylmethyldimethoxysilane; and / or, the catalyst is at least one of hydrochloric acid, sulfuric acid, or phosphoric acid.

4. The method for preparing a self-healing thermally conductive silicone rubber for connectors according to claim 1, characterized in that: The weight ratio of the phenyl-acryloyloxy silicone emulsion, emulsifier, initiator, and mixed monomers containing acrylate and graft crosslinking agent is 207-307:0.5-1:0.1-0.5:40-60:0.5-1; and / or, the acrylate is any one or more of ethyl acrylate, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, cyclohexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, isobornyl methacrylate, phenyl methacrylate, or benzyl methacrylate; and / or, the graft crosslinking agent is any one or more of allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl itaconic acid, monoallyl maleate, or monoallyl fumarate.

5. The method for preparing a self-healing thermally conductive silicone rubber for connectors according to claim 1, characterized in that: The weight ratio of the phenyl-acryloyloxysilicone modified acrylate copolymer emulsion, the initiator, and methyl methacrylate is: 248.1-369.5：0.1-0.5：30-50。 6. A toughening agent, characterized in that: It is prepared using the method for preparing a self-healing thermally conductive silicone rubber for a connector according to any one of claims 1-5.

7. The toughening agent prepared by the method for preparing self-healing thermally conductive silicone rubber for connectors according to any one of claims 1-5, or the application of the toughening agent according to claim 6, is characterized in that: Used in polymethyl methacrylate resin.

8. A method for preparing a chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition, characterized in that: The toughening agent is prepared using the method for preparing a self-healing thermally conductive silicone rubber for connectors according to any one of claims 1-5, or the toughening agent according to claim 6.

9. A method for preparing a self-healing thermally conductive silicone rubber for connectors according to claim 8, characterized in that: The phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer emulsion was heated, a demulsifier was added, and the reaction continued. After filtration, washing, and drying, phenyl-acryloyloxysilicone / acrylate / methyl methacrylate graft copolymer powder was obtained.

10. A chemically resistant, highly transparent, and low-haze polymethyl methacrylate resin composition, characterized in that: The toughening agent is prepared by the method of preparing a self-healing thermally conductive silicone rubber for connectors according to any one of claims 1-5, or the toughening agent according to claim 6.

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