A pmma composition, its preparation and use

Abstract

The application discloses a PMMA composition and a preparation method and application thereof. The preparation method of the PMMA comprises the step of melt mixing materials in an extruder, wherein the area where a screw is located is sequentially divided into a primary section, a middle section and a tail section in the extrusion direction, the PMMA resin and dilute hydrochloric acid in the materials are fed from the feeding port of the primary section, the activator and POK resin are fed from the feeding port of the middle section, and the processing aid is fed from the feeding port of the tail section; and the materials are cut into particles after being extruded, so that the PMMA composition is obtained. The PMMA composition obtained by the application has good solvent resistance, can improve the solvent resistance of a double-shot welding position, and avoids cracking of a vehicle lamp.

Description

Technical Field

[0001] This invention relates to a PMMA composition, and more particularly to a PMMA composition, its preparation method, and its application. Background Technology

[0002] PMMA, or polymethyl methacrylate, is characterized by high light transmittance and good weather resistance, and is widely used in automotive taillights. Due to automotive regulations and headlight design requirements, different PMMAs need to be injection molded using a dual-injection molding machine. This inevitably leads to weld lines between the front and rear injection molded materials in the lamp cover, which can cause cracking when exposed to detergents such as alcohol during car washes. Patent CN116218115B reports a method using ASA to toughen PMMA, relying on the synergistic effect of silicone masterbatch and graphene oxide to improve solvent resistance; however, the product color is limited to black, restricting its application scenarios. Patent CN116218115B uses SAN to improve PMMA's solvent resistance and a toughening agent to improve PMMA's toughness, but its application scenario is film fabrication, and the weld line performance of automotive headlight injection molding was not tested.

[0003] POK material exhibits excellent resistance to temperature, acid, and alkali corrosion, gas barrier properties, and abrasion resistance, while also possessing high tensile and impact strength. Patent CN116554625A discloses a modification scheme for PMMA using POK, but different product applications have different focuses on performance improvement, and it fails to address how to enhance the weld strength of two-shot injection molding to meet the requirements of automotive lighting applications. Summary of the Invention

[0004] To address the above technical problems, this invention proposes a PMMA composition, its preparation method, and its applications. The PMMA composition obtained by this invention exhibits excellent solvent resistance, which can improve the solvent resistance strength of the double-shot weld joint and prevent cracking of the headlights.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a PMMA composition includes a step of melting and mixing materials in an extruder, wherein the area where the screw is located is divided into an initial section, a middle section, and a tail section according to the extrusion direction, the PMMA resin and dilute hydrochloric acid in the material are fed from the initial section inlet, the activator and POK resin are fed from the middle section inlet, and the processing aid is fed from the tail section inlet. After the material is extruded, it is pelletized to obtain the PMMA composition.

[0007] In the preparation method of this invention, PMMA resin and dilute hydrochloric acid are added first, which can cause ester bond hydrolysis to a certain extent, resulting in hydrolysis products containing ester and carboxyl groups; POK resin and activator are added simultaneously from the middle section of the screw, which can introduce certain amine side chains into the POK resin through nucleophilic addition, and then react with the partially hydrolyzed PMMA chain segments to obtain a chemically bonded special structure resin. This improves the reactivity and compatibility of PMMA and enhances the weld strength of the second injection molding. At the same time, POK forms a solvent barrier layer, maintaining the good solvent crack resistance of POK itself.

[0008] In a preferred embodiment of the present invention, the processing temperature of the initial stage is 180-190°C; the processing temperature of the middle stage is 210-240°C, and the vacuum degree is -0.04MPa to -0.2MPa; the processing temperature of the tail stage is 240-250°C.

[0009] In a preferred embodiment of the present invention, for an extruder with a total screw length divided into 10 zones, the initial section is located in zones 1-2 of the total screw length, the middle section is located in zones 3-6 of the total screw length, and the tail section is located in zones 7-10 of the total screw length.

[0010] In a preferred embodiment of the present invention, the amount of material used is expressed in parts by mass, including:

[0011] PMMA resin, 40-95 parts, preferably 80-95 parts;

[0012] POK resin, 10-50 parts, preferably 12-40 parts;

[0013] Activator, 2-15 parts, preferably 2-10 parts;

[0014] Processing aid, 0-2 parts, preferably 0.01-2 parts;

[0015] Dilute hydrochloric acid, 0.001-0.05 parts, preferably 0.003-0.03 parts.

[0016] In a preferred embodiment of the present invention, the PMMA resin has a viscosity-average molecular weight of 10,000-15,000, preferably 12,000-14,000, and a molecular weight distribution of 1.6-2.5, preferably 1.8-2.2.

[0017] Preferably, the PMMA resin is selected from one or more of Wanhua HDS01, Wanhua HDS02, and Wanhua HDS03.

[0018] In a preferred embodiment of the present invention, the melt index of the POK resin under test conditions of 240°C and 2.16 kg is 3-200 g / 10 min, preferably 6-150 g / 10 min;

[0019] Preferably, the POK resin is selected from one or more of Hyosung's M620A, M330A, and M230A from South Korea.

[0020] In a preferred embodiment of the present invention, the activator is one or more of 2,2,4-trimethylhexamethylenediamine, tetramethylpropylenediamine, and hydroxyethylethylenediamine;

[0021] Preferably, the processing aid includes an antioxidant; more preferably, the antioxidant is one or more of hindered phenols, benzofurans, acryloyl-modified phenols, and hydroxylamine antioxidants.

[0022] In a preferred embodiment of the present invention, the dilute hydrochloric acid is an aqueous solution of hydrochloric acid with a molar concentration of 0.01-0.03 mol / L.

[0023] The present invention also provides a PMMA composition prepared according to the method described above.

[0024] The present invention also proposes the application of the PMMA composition prepared according to the method described above in automotive lamps, particularly in dual-injection molded automotive lamp products.

[0025] This invention achieves ordered reactive extrusion of the composition through formula optimization and adjustment of the feeding sequence. The resulting product has high weld strength and solvent resistance, and can be widely used in PMMA automotive lighting applications using two-shot injection molding. Detailed Implementation

[0026] The present invention will be further illustrated below with specific embodiments. These embodiments are merely illustrative and do not limit the scope of the invention.

[0027] The main raw materials used in this invention are as follows; unless otherwise specified, all other raw materials are commercially available:

[0028] PMMA resin HDS01, viscosity-average molecular weight 11000, molecular weight distribution 1.9, Wanhua Chemical

[0029] PMMA resin HDS02, viscosity-average molecular weight 15000, molecular weight distribution 1.6, Wanhua Chemical

[0030] PMMA resin HDS03, viscosity-average molecular weight 13000, molecular weight distribution 2.5, Wanhua Chemical

[0031] POK resin M620A, with a melt index of 6 g / 10 min under test conditions of 240℃ and 2.16 kg, is from Hyosung, South Korea.

[0032] POK resin M330A, with a melt index of 60 g / 10 min under test conditions of 240℃ and 2.16 kg, is from Hyosung, South Korea.

[0033] POK resin M230A, with a melt index of 150 g / 10 min under test conditions of 240℃ and 2.16 kg, is from Hyosung, South Korea.

[0034] The main testing methods involved in the following embodiments of the present invention are as follows:

[0035] Stress cracking resistance: Using ISO 527-2:2017 specimens, clamped with a 1% bending strain fixture, and continuously sprayed with 90% alcohol, the fracture time of the specimens was recorded;

[0036] Welded tensile strength performance: Using a mold of half the sample length according to ISO 527-2:2017, double injection molding was used. The sample was immersed in 90% alcohol for 3 minutes before testing. The tensile test speed was 5 mm / min.

[0037] Bending test: Tested according to ISO 178:2019, test speed 2mm / min;

[0038] Impact strength test: ISO 180:2019, unnotched, test temperature is room temperature.

[0039]

Example 1

[0040] Prepare the materials according to the following formula:

[0041] PMMA resin HDS01, 40kg;

[0042] POK resin M620A, 40kg;

[0043] Activator 2,2,4-trimethylhexamethylenediamine, 2 kg;

[0044] Antioxidant 1076, 0.2 kg;

[0045] Dilute hydrochloric acid, 0.01 mol / L, 0.001 kg;

[0046] The PMMA composition was prepared according to the following method:

[0047] 1) The raw materials are melt-blended using an extruder with 10 zones of screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 180℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.1MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 240℃.

[0048] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0049]

Example 2

[0050] Prepare the materials according to the following formula:

[0051] PMMA resin HDS03, 40kg;

[0052] POK resin M620A, 45kg;

[0053] Activator: Tetramethylpropanediamine, 15 kg;

[0054] Antioxidant 1010, 2 kg;

[0055] Dilute hydrochloric acid, 0.01 mol / L, 0.03 kg;

[0056] The PMMA composition was prepared according to the following method:

[0057] 1) The raw materials are melt-blended using an extruder with 10 zones of screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 190℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.2MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 250℃.

[0058] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0059]

Example 3

[0060] Prepare the materials according to the following formula:

[0061] PMMA resin HDS01, 95kg;

[0062] POK resin M620A, 10kg;

[0063] Activator: hydroxyethyl ethylenediamine, 2 kg;

[0064] Antioxidant 168,000 kg;

[0065] Dilute hydrochloric acid, 0.01 mol / L, 0.003 kg;

[0066] The PMMA composition was prepared according to the following method:

[0067] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 185℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 240℃ and vacuum at -0.04MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 245℃.

[0068] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0069]

Example 4

[0070] Prepare the materials according to the following formula:

[0071] PMMA resin HDS01, 85kg;

[0072] SMA resin M330A, 12kg;

[0073] Activator: hydroxyethyl ethylenediamine, 8 kg;

[0074] Antioxidant 1076, 0.2 kg;

[0075] Dilute hydrochloric acid, 0.01 mol / L, 0.003 kg;

[0076] The PMMA composition was prepared according to the following method:

[0077] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 185℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 225℃ and vacuum at -0.1MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 240℃.

[0078] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0079]

Example 5

[0080] Prepare the materials according to the following formula:

[0081] PMMA resin HDS01, 40kg;

[0082] SMA resin M230A, 40kg;

[0083] Activator 2,2,4-trimethylhexamethylenediamine, 2 kg;

[0084] Antioxidant 1076, 0.2 kg;

[0085] Dilute hydrochloric acid, 0.01 mol / L, 0.003 kg;

[0086] The PMMA composition was prepared according to the following method:

[0087] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 180℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 225℃ and vacuum at -0.04MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 250℃.

[0088] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0089]

Example 6

[0090] Prepare the materials according to the following formula:

[0091] PMMA resin HDS02, 40kg;

[0092] POK resin M620A, 40kg;

[0093] Activator: Tetramethylpropanediamine, 2 kg;

[0094] Antioxidant 1076, 0.2 kg;

[0095] Dilute hydrochloric acid, 0.01 mol / L, 0.001 kg;

[0096] The PMMA composition was prepared according to the following method:

[0097] 1) The raw materials are melt-blended using an extruder with 10 zones of screw length. In zone 1, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 1-2 is set at 190℃. In zone 4, activator and POK are added, and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.1MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 250℃.

[0098] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0099] Comparative Example 1

[0100] The PMMA composition was prepared according to essentially the same material formulation and method as in Example 1, except that all materials were added in zone 1 of the extruder.

[0101] Comparative Example 2

[0102] The PMMA composition was prepared using the same material formulation as in Example 1, except that the preparation method of the PMMA composition was as follows:

[0103] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, activator and POK resin are added, and the temperature of zones 1-2 is set at 180℃. In zone 4, PMMA resin and dilute hydrochloric acid are added, and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.1MPa. In zone 7, antioxidant is added, and the temperature of zones 7-10 is set at 240℃.

[0104] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0105] Comparative Example 3

[0106] The PMMA composition was prepared using the same material formulation as in Example 1, except that the preparation method of the PMMA composition was as follows:

[0107] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, PMMA resin is added and the temperature of zones 1-2 is set at 180℃. In zone 4, activator, dilute hydrochloric acid and POK resin are added and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.1MPa. In zone 7, antioxidant is added and the temperature of zones 7-10 is set at 240℃.

[0108] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0109] Comparative Example 4

[0110] The PMMA composition was prepared using the same material formulation as in Example 1, except that the preparation method of the PMMA composition was as follows:

[0111] 1) The raw materials are melt-blended using an extruder with 10 zones along the screw length. In zone 1, PMMA resin and antioxidant are added, and the temperature of zones 1-2 is set at 180℃. In zone 4, activator and POK resin are added, and the temperature of zones 3-6 is set at 210℃ and vacuum at -0.1MPa. In zone 7, dilute hydrochloric acid is added, and the temperature of zones 7-10 is set at 240℃.

[0112] 2) Granulation: The extruded strip is passed through 50°C water, cooled for 10 seconds, drawn into strips, and granulated to obtain the PMMA composition.

[0113] The performance of the PMMA compositions prepared in each example and comparative example was tested, and the results are shown in Table 1:

[0114] Table 1. Performance test results of PMMA compositions

[0115]

[0116] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and additions without departing from the method of the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a PMMA composition, characterized in that, The process includes a step of melting and mixing materials in an extruder, wherein the area where the screw is located is divided into an initial section, a middle section, and a tail section according to the extrusion direction. PMMA resin and dilute hydrochloric acid are fed into the initial section inlet, activator and POK resin are fed into the middle section inlet, and processing aids are fed into the tail section inlet. After extrusion, the material is pelletized to obtain a PMMA composition. The activator is one or more of 2,2,4-trimethylhexamethylenediamine, tetramethylpropylenediamine, and hydroxyethylethylenediamine. Material usage is expressed in parts by weight, including: PMMA resin, 40-95 parts POK resin, 10-50 parts Activator, 2-15 parts Processing aids, 0-2 parts, Dilute hydrochloric acid, 0.001-0.05 parts; The dilute hydrochloric acid is an aqueous solution of hydrochloric acid with a molar concentration of 0.01-0.03 mol / L.

2. The method for preparing the PMMA composition according to claim 1, characterized in that, The initial processing temperature is 180-190℃; the middle processing temperature is 210-240℃, and the vacuum degree is -0.04MPa to -0.2MPa; the final processing temperature is 240-250℃.

3. The method for preparing the PMMA composition according to claim 1, characterized in that, For an extruder with a total screw length divided into 10 zones, the initial section is located in zones 1-2 of the total screw length, the middle section is located in zones 3-6 of the total screw length, and the tail section is located in zones 7-10 of the total screw length.

4. The method for preparing the PMMA composition according to any one of claims 1-3, characterized in that, Material usage is expressed in parts by weight, including: PMMA resin, 80-90 parts; POK resin, 12-40 parts; Activator, 2-10 parts; Processing aids, 0.01-2 parts; Dilute hydrochloric acid, 0.003-0.03 parts.

5. The method for preparing the PMMA composition according to any one of claims 1-3, characterized in that, The PMMA resin has a viscosity-average molecular weight of 10,000-15,000 and a molecular weight distribution of 1.6-2.

5.

6. The method for preparing the PMMA composition according to claim 5, characterized in that, The PMMA resin has a viscosity-average molecular weight of 12,000-14,000 and a molecular weight distribution of 1.8-2.

2.

7. The method for preparing the PMMA composition according to any one of claims 1-3, characterized in that, The POK resin has a melt flow index of 3-200 g / 10 min under test conditions of 240℃ and 2.16 kg.

8. The method for preparing the PMMA composition according to claim 7, characterized in that, The POK resin has a melt flow index of 6-150 g / 10 min under test conditions of 240℃ and 2.16 kg.

9. The method for preparing the PMMA composition according to claim 7, characterized in that, The POK resin is selected from one or more of Hyosung's M620A, M330A, and M230A from South Korea.

10. A method for preparing the PMMA composition according to any one of claims 1-3, characterized in that, The processing aids include antioxidants.

11. The method for preparing the PMMA composition according to claim 10, characterized in that, The antioxidant is one or more of hindered phenols, benzofurans, acryloyl-modified phenols, and hydroxylamine antioxidants.

12. A PMMA composition prepared by the method according to any one of claims 1-11.

13. The use of a PMMA composition prepared according to any one of claims 1-11 in automotive headlights.

14. The use of a PMMA composition prepared according to any one of claims 1-11 in two-shot injection molded automotive lighting products.

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