A PMMA material and its preparation method and application

Abstract

The present invention belongs to the field of polymer materials technology, specifically relating to a PMMA material, its preparation method, and its application. The PMMA material comprises the following components, measured in parts by weight: 85-96 parts PMMA resin, 4-10 parts acrylic copolymer, 1-10 parts polyvinyl alcohol, and 0.3-1 part carboxylated graphene. The PMMA material produced by the present invention effectively overcomes the shortcomings of the prior art, resulting in a PMMA material with low surface resistivity, resistance to dust absorption and fingerprint residue, and excellent wear and scratch resistance. Furthermore, the present invention simplifies the molding process and has good industrial application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of polymer materials, and in particular relates to a PMMA material and a preparation method and application thereof. Background Art

[0002] With the increasing application of spray-free materials in recent years, the application of PMMA materials has become more and more extensive, and more and more terminal products have put forward higher requirements on the surface dust absorption, fingerprint residue and scratch resistance of PMMA and its alloy materials.

[0003] Chinese patent application CN106009476A discloses a high-hardness impact PMMA / ABS composite material. MBS serves as a toughening agent and a polyester-grafted silicone additive serves as a surface modifier to improve brittleness and achieve high hardness and impact resistance. However, the alloy suffers from insufficient toughness. The addition of polyester-grafted silicone only imparts a surface modification effect, but lacks synergistic toughening with MBS, requiring the addition of a compatibilizer.

[0004] Chinese patent CN111154210B discloses a toughened scratch-resistant PMMA material and a preparation method thereof, which improves the scratch resistance of the surface, but does not describe the dust resistance.

[0005] Due to existing technical limitations, the main defects of high-gloss black PMMA and its alloy materials for automotive interior and exterior decoration compared with painted parts are easy to absorb dust, easy to leave fingerprints, and poor resistance to soft scratches (such as scratches from wind and sand, fingernails, keys, etc.) during use. Summary of the Invention

[0006] The present invention provides a PMMA material, a preparation method, and applications thereof. The PMMA material produced by the present invention effectively overcomes the shortcomings of the prior art, resulting in a PMMA material with low surface resistivity, low dust absorption, and fingerprint resistance, while also exhibiting wear and scratch resistance.

[0007] To achieve the above objectives, the present invention employs the following technical solution: a PMMA material comprising the following components, in parts by weight: 85-96 parts PMMA resin, 4-10 parts acrylic copolymer, 1-10 parts polyvinyl alcohol, and 0.3-1 part carboxylated graphene. The addition of the acrylic copolymer enhances toughness while also providing excellent weather resistance, high gloss, and reproducible workability, significantly improving the performance of the PMMA material system.

[0008] Preferably, the PMMA material comprises the following components in parts by weight: 88-93 parts of PMMA resin, 6-8 parts of acrylic copolymer, 5-7 parts of polyvinyl alcohol, and 0.5-0.6 parts of carboxylated graphene.

[0009] Preferably, the density of the acrylic copolymer is 1.08 to 1.15 g / cm 3 The test standard is ISO 1183-1:2019, with a hardness range of 18 to 64. The test standard is ISO 7619-1:2010 Type D. Acrylate copolymers are composed of PMMA, PnBA, and block copolymer. Different ratios of these three components can produce copolymers with varying densities and hardnesses. Acrylates within this density and hardness range are highly compatible with PMMA.

[0010] More preferably, the density of the acrylic copolymer is 1.10 to 1.13 g / cm 3 , hardness is 34~55.

[0011] Preferably, the melt index of the PMMA resin under the test conditions of 230° C. and 3.8 kg is 1.8 to 6.0 g / 10 min. The melt index test standard in the present invention is ISO 1133-2012.

[0012] More preferably, the melt index of the PMMA resin under the test conditions of 230° C. and 3.8 kg is 2 to 5.5 g / 10 min.

[0013] Preferably, the polyvinyl alcohol is prepared by suspension polymerization of vinyl chloride solution in the presence of vinyl acetate emulsifier.

[0014] Preferably, the alcoholysis degree of the polyvinyl alcohol is 98% to 100%, and the testing standard is in accordance with GB / T 12010.2-2010 Plastic Polyvinyl Alcohol Materials.

[0015] Preferably, the viscosity of the polyvinyl alcohol is 4.5×10 -3 ~25.0×10 -3 Pa·S. Viscosity test standard is in accordance with GB 12010.3-1989, Determination of viscosity of polyvinyl alcohol resin.

[0016] More preferably, the viscosity of the polyvinyl alcohol is 12.0×10 -3 ~16.0×10 -3 Pa.S.

[0017] Preferably, the acrylic copolymer is a block copolymer consisting of PMMA-PnBA rubber-PMMA. The toughening effect of the copolymer is mainly determined by PnBA. The PnBA content is generally 40%-60%. The higher the PnBA content, the softer the copolymer and the lower the density, but the worse the compatibility with the PMMA matrix. The content of PMMA hard segments in the copolymer determines the hardness of the copolymer and its compatibility with the matrix. The key properties of the copolymer are hardness and density.

[0018] Preferably, the PMMA material further includes 0.5 to 4 parts of an auxiliary agent.

[0019] Preferably, the auxiliary agent includes at least one of an antioxidant, a lubricant, and a weathering agent.

[0020] More preferably, the antioxidant includes antioxidant 1010, antioxidant 168, etc.; the lubricant includes pentaerythritol stearate, etc.; the weathering agent includes benzotriazole light stabilizer, etc.

[0021] A method for preparing the PMMA material comprises the following steps:

[0022] After weighing each component in proportion, the components are mixed evenly, extruded and granulated to obtain PMMA material.

[0023] Preferably, the temperature of the extrusion granulation is 200-240°C.

[0024] An application of the PMMA material in the preparation of automotive interior and exterior decoration, such as air intake grilles, exterior column trims, rearview mirror housings, etc.

[0025] The present invention compounds carboxylated graphene with polyvinyl alcohol and performs extrusion modification, wherein the carboxyl groups of the carboxylated graphene react with the alcoholic hydroxyl groups of the polyvinyl alcohol to generate a small amount of water. Through dispersion and mixing, a small amount of water vapor is distributed to the melt surface and then extracted from a vacuum port under the action of vacuum negative pressure, leaving a network structure formed by the reaction of the graphene and the polyvinyl alcohol. The network structure can be connected to a base PMMA material under the action of an acrylic copolymer, thereby further improving the compatibility, thereby achieving the effects of reducing the surface resistivity of the material, reducing dust absorption performance, reducing fingerprint residue, and improving the wear resistance, scratch resistance, and impact resistance of the material.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] (1) The carboxylated graphene and meltable polyvinyl alcohol of the present invention undergo a chemical reaction during the extrusion blending and modification process. At the same time, the acrylic copolymer acts as a bridge to maximize the synergistic effect of graphene and polyvinyl alcohol, thereby improving the wear resistance and oil resistance of the material, and further improving the fingerprint resistance and scratch resistance. At the same time, the addition of the acrylic copolymer toughening agent alleviates the effect of the graphene modifier on the toughness of the material, further improving the wear resistance, scratch resistance and impact resistance of the PMMA material.

[0028] (2) The PMMA material prepared by the present invention has excellent performance, improves the use experience of PMMA and its alloy materials, and has good industrial utilization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the scratch resistance level in the performance test of the present invention. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0031] In the following examples and comparative examples, unless otherwise specified, antioxidants and lubricants were commercially available and the same ones were used in parallel experiments.

[0032] The raw materials used in the examples and comparative examples are shown in Table 1.

[0033] Table 1

[0034]

[0035]

[0036]

[0037] Examples 1 to 15 and Comparative Examples 1 to 6

[0038] The components and weight proportions of the PMMA materials of Examples 1 to 15 and Comparative Examples 1 to 6 are shown in Tables 2 and 3.

[0039] The preparation method of the PMMA materials of Examples 1 to 15 and Comparative Examples 1 to 6 comprises the following steps:

[0040] After weighing each component in proportion, the components were mixed uniformly to obtain a premix, and then the premix was extruded and granulated at a temperature of 220° C. through a twin-screw extruder to obtain a PMMA material.

[0041] Table 2 Component dosage (parts by weight)

[0042]

[0043] Table 3 Component dosage in comparative example (parts by weight)

[0044]

[0045] Performance Testing

[0046] The performance tests were conducted on the PMMA materials prepared in Examples 1 to 15 and Comparative Examples 1 to 6. The specific test methods and conditions are as follows:

[0047] 1. Mechanical properties (Charpy impact strength): tested in accordance with ISO 179-1:2010, injection molded into 80mm×10mm×4mm, A-notch standard specimens;

[0048] 2. Scratch resistance (cross-hatch): Tested in accordance with PV3952:2019, weight F = 20N, test rate v = 1000mm / min, interval 2mm, hard metal tip diameter 1mm, observed under a 2D electron microscope with a magnification of 60 times, divided into 6 levels, with level 1 being the best and level 6 being the worst. See the attached diagram for a schematic diagram. Figure 1 (PMMA scratches are generally smaller than 0.4mm, and even if they appear white, they are difficult to evaluate using color difference, so a secondary electron microscope is used to classify the grades).

[0049] 3. Linear wear test:

[0050] Prepare the sample from a high-gloss mold or actual mold part with a polish of 8000 ± 100 mesh. The sample surface must be clean and free of external defects. The sample size should be ≥ 110mm * 110mm * 2mm. Use a Taber linear abraser to test at least three specimens. The method is as follows:

[0051] 1) Use a round double-sided tape to attach a 3 / 4-inch diameter friction head (Taber part number 131434) to a 1-inch diameter friction disc (Taber part number 130572). Then, attach the assembled friction disc to the weight rack and level the weight rack with a balance weight.

[0052] 2) Set the equipment parameters and load: friction rate 25 cycles / min, friction stroke 75mm, friction cycle 10 times, load 8N;

[0053] 3) Use a BYK or Konica Minolta three-angle gloss tester to test the gloss of the friction area before and after friction (20° reflection angle), and calculate the gloss residual rate (gloss residual rate = gloss after test / gloss before test × 100%).

[0054] Note: The friction head must be ground flat each time a test is conducted to ensure the effectiveness of the test. The surface of the sample must be cleaned for gloss testing after friction.

[0055] 4. Antistatic performance: Characterized by surface resistivity, <10 13 ohms / sq has certain antistatic properties and can achieve dust resistance. The test standard is GB / T 1410-2006, and the test conditions are voltammetry 100V.

[0056] 5. Fingerprint resistance: Self-prepared, use your thumb to rotate Vaseline (Vaseline Classic Repair Crystal Jelly 50g) clockwise 5 times, then rub it clockwise on the sample (80mm×55mm) 5 times, and then use absorbent cotton to clean off the coated Vaseline. Finally, test the color difference of the sample before and after coating. The smaller the color difference, the better the fingerprint resistance.

[0057] The performance test results are shown in Table 4.

[0058] Table 4 Performance test results

[0059]

[0060]

[0061] From the data in Table 4, it can be seen that the PMMA material prepared in the embodiment of the present invention has good mechanical properties, wear resistance, scratch resistance, fingerprint resistance, and good antistatic properties. Among them, the notched impact strength can be maintained at 3.9~5.4kJ / m 2 The scratch resistance (cross-hatch) can be maintained at levels 1 to 4, the linear wear resistance gloss retention rate can be achieved in the range of 23 to 40%, and the surface resistivity can be maintained at 10 10 ~10 14 ohms / sq, the anti-fingerprint performance can be maintained in the color difference range of 0.5 to 4.2.

[0062] In Comparative Examples 1 and 2, no acrylic copolymer is added or an equal amount of silicone rubber is used to replace the acrylic copolymer, and the resulting PMMA materials have poor notched impact strength, scratch resistance, and wear resistance, and have a higher surface resistivity. In Comparative Example 3, no polyvinyl alcohol is added, and the PMMA material obtained has scratch resistance and wear resistance that are worse than those in the embodiment. In Comparative Example 4, an equal amount of graphene oxide is used to replace carboxylated graphene, and the resulting PMMA material has poor scratch resistance and wear resistance. In Comparative Examples 5 and 6, the weight of the PMMA resin added is inappropriate, resulting in the notched impact strength of the resulting PMMA materials being affected, and the scratch resistance and wear resistance are also worse than those in the embodiment.

[0063] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A PMMA material, characterized in that: The invention comprises the following components in parts by weight: 85-96 parts of PMMA resin, 4-10 parts of acrylic copolymer, 1-10 parts of polyvinyl alcohol, and 0.3-1 part of carboxylated graphene; the acrylic copolymer is a block copolymer composed of PMMA-PnBA rubber-PMMA; the density of the acrylic copolymer is 1.08-1.15 g / cm 3 , the test standard is ISO 1183-1:2019, the hardness is 18 to 64, and the test standard is ISO 7619-1:2010 type D.

2. The PMMA material according to claim 1, wherein The invention comprises the following components in parts by weight: 88-93 parts of PMMA resin, 6-8 parts of acrylic copolymer, 5-7 parts of polyvinyl alcohol and 0.5-0.6 part of carboxylated graphene.

3. The PMMA material according to claim 1, wherein At least one of the following (1) to (2): (1) The melt index of the PMMA resin under the test conditions of 230°C and 3.8 kg is 1.8 to 6.0 g / 10 min; (2) The viscosity of the polyvinyl alcohol is 4.5×10 -3 ~25.0×10 -3 Pa.S.

4. The PMMA material according to claim 3, wherein: At least one of the following (1) to (3): (1) The density of the acrylic copolymer is 1.10 to 1.13 g / cm 3 , hardness is 34-55; (2) The melt index of the PMMA resin under the test conditions of 230° C. and 3.8 kg is 2 to 5.5 g / 10 min; (3) The viscosity of the polyvinyl alcohol is 12.0×10 -3 ~16.0×10 -3 Pa.S.

5. The PMMA material according to claim 1 or 2, characterized in that: It also includes 0.5 to 4 parts of auxiliary agents.

6. The PMMA material according to claim 5, characterized in that The auxiliary agent includes at least one of an antioxidant, a lubricant, and a weathering agent.

7. A method for preparing the PMMA material according to any one of claims 1 to 6, characterized in that: The following steps are involved: After weighing each component in proportion, the components are mixed, extruded and granulated to obtain PMMA material.

8. The preparation method according to claim 7, wherein: The temperature of the extrusion granulation is 200-240°C.

9. Use of the PMMA material according to any one of claims 1 to 6 in the preparation of automobile interior and exterior decoration.

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