Composition and method for preparing modified polymethyl methacrylate alloy

Abstract

The invention discloses a composition and a method for preparing a modified polymethyl methacrylate alloy. The composition is prepared from the following components in parts by mass: 55 to 83.88 parts of a polymethyl methacrylate base material, 14.00 to 42.42 parts of a toughening agent, 0.06 to 3.3 parts of toner, 0.11 to 0.48 part of a lubricating agent, 0.05 to 0.50 part of an antioxidant, 0.03 to 0.2 part of a release agent, 0.15 to 1.5 parts of a light stabilizer, 0.05 to 0.16 part of a residue initiator and 0.1 to 0.5 part of a residue azeotropic solvent. The alloy can be widely applied to preparation of a dyed PMMA material and a toughened PMMA material, and the monomer residual quantity in the prepared material is lower than that of a conventional modified PMMA alloy product.

Description

Technical Field

[0001] The invention belongs to the field of polymer material products and product processing, and relates to a toughened polymethyl methacrylate alloy and a preparation method thereof. Background Art

[0002] Polymethyl methacrylate (PMMA) is a commonly used polymer material with high light transmittance and low haze. Due to its excellent high-temperature fluidity, ease of processing, and dyeability, it is widely used in automotive and motorcycle lighting. However, due to its poor mechanical properties and brittle nature, if PMMA is to be used to create thin films utilizing its optical properties, a toughening agent must be added to enhance the toughness of the material. This allows the preparation of film-forming materials for tape casting. For example, Chinese patent CN117417616A describes a PMMA composition and its preparation method. CN107841077A improves material toughness by adding SMA resin.

[0003] Toughening agents are usually applied to colloidal materials with a core-shell structure. Due to their strong toughness, when preparing alloy materials with PMMA, a screw combination with strong shearing force is required to achieve good microscopic dispersion of the toughening agent and PMMA and achieve uniform toughening. However, PMMA itself is not resistant to strong shearing force. As described in many articles such as "A Brief Analysis of Thermal Degradation Research of Polymethyl Methacrylate" (Lv Guojun, Heilongjiang Zhongmeng Longxin Chemical Co., Ltd., Inner Mongolia Petrochemical. 2010, 36(09)) and "Research Progress on Thermal Degradation of Polymethyl Methacrylate" (Zeng Wenru et al., Polymer Materials Science and Engineering. 2003(03)), when the temperature of PMMA rises above 220℃, it will decompose, thereby producing some small molecular substances. When PMMA is extruded using a strong shearing screw combination, the kneading section temperature often reaches above 220℃, so PMMA will degrade, and a large amount of monomer residue will be produced during degradation. The book "Methacrylic Resins and Their Applications" (Ma Zhanbiao, Chemical Industry Press, 1st edition, January 2002) describes monomers as primarily MMA (methyl methacrylate), MA (methyl acrylate), EA (ethyl acrylate), DM (dimethylaminoethyl methacrylate), and DMMA (an oligomer of MMA and DM). Excessive residual levels of these monomers can affect the mechanical properties of the material, resulting in abnormalities such as fisheyes and breakage during the cast film process, as well as low elongation at break and significant data fluctuations during material testing. PMMA and toughening agents are generally poorly compatible, requiring a high-shear screw assembly to achieve uniform dispersion of the toughening agent in PMMA. These two factors are therefore contradictory. To improve product quality, a high-shear screw assembly is required to disperse the toughening agent while simultaneously minimizing the amount of monomer produced to maintain good material properties. Summary of the Invention

[0004] To address the problem of excessive residual monomers in PMMA alloy products used in toughening films, the present invention provides a composition and method for preparing a modified polymethyl methacrylate alloy. This method, based on a conventional dyed PMMA formula, adds a methacrylate residual initiator and an azeotropic solvent to the formula. During the extrusion process, the residual methacrylate is further polymerized, and the azeotropic solvent removes more of the residual monomers from the extruder, thereby reducing the amount of residual monomers.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] A composition for preparing a modified polymethyl methacrylate alloy, comprising the following components in parts by mass:

[0007] 55 to 83.88 parts of polymethyl methacrylate substrate, preferably 65 to 77 parts;

[0008] 14.00 to 42.42 parts of toughening agent, preferably 20.31 to 30.22 parts;

[0009] Color powder 0.06 to 3.3 parts, preferably 0.16 to 2.6 parts;

[0010] 0.11 to 0.48 parts of lubricant, preferably 0.23 to 0.42 parts;

[0011] 0.05-0.50 parts of antioxidant, preferably 0.13-0.41 parts;

[0012] 0.03-0.2 parts of release agent, preferably 0.05-0.1 parts;

[0013] 0.15 to 1.5 parts of light stabilizer, preferably 0.35 to 0.8 parts;

[0014] 0.05 to 0.16 parts of residual initiator, preferably 0.06 to 0.12 parts;

[0015] The amount of the residue azeotropic solvent is 0.1 to 0.5 parts, preferably 0.06 to 0.12 parts.

[0016] A method for preparing the alloy of the present invention comprises the following steps: mixing the components, melting and extruding the components in an extruder, and pelletizing the components to obtain a finished product.

[0017] The residual monomer content in the alloy of the present invention is lower than that of a modified PMMA product in which no residual initiator and / or azeotropic solvent is added to the formula.

[0018] The viscosity-average molecular weight of the polymethyl methacrylate substrate of the present invention is 80,000 to 18,000, preferably 10,000 to 15,000; preferably, one or more of Wanhua Chemical products HD01, HD03, HD04, HD08L, etc.

[0019] The toughening agent of the present invention is a core-shell copolymer, including but not limited to one or more of ABS, MBS, ASA, SBS and the like.

[0020] The color powder of the present invention includes but is not limited to one or more of carbon black, 4-(2-methylbutenyl)benzoic acid, red iron oxide, black iron oxide, phthalocyanine blue BGS, etc.

[0021] The lubricant described in the present invention includes but is not limited to one or more of polyethylene glycol 4000, polyethylene glycol 6000, polyethylene wax, pentaerythritol stearate, etc.

[0022] The antioxidant described in the present invention includes but is not limited to one or more of 1076 (BASF), H3311 (Yantai Xinte Road), AO3352 (Yantai Xinte Road), 1010 (BASF), hydroquinone, etc.

[0023] The release agent of the present invention includes but is not limited to one or more of paraffin, stearic acid, octadecanol, hexadecanoic acid, dimethyl silicone oil and the like.

[0024] The light stabilizer of the present invention includes but is not limited to one or more of UV-531 (BASF), UV-360 (BASF), 2,4-dihydroxybenzophenone, P4808NA (Sabik), 4069 (DuPont), etc.

[0025] The residual initiator described in the present invention includes but is not limited to one or more of AIBN (Aladdin reagent), BPO (Aladdin reagent), HMPP (Aladdin reagent), DMPA (Aladdin reagent), DCP (Aladdin reagent), etc.

[0026] The residue azeotropic solvent of the present invention includes, but is not limited to, one or more of water, ethanol, isopropanol, methanol, n-butanol, and the like.

[0027] As a preferred solution, the electrical conductivity of the water is less than 50 μc / cm, preferably less than 10 μc / cm.

[0028] As a preferred solution, the purity of the ethanol is ≥95vt%.

[0029] In the alloy preparation method of the present invention, the extruder is a twin-screw extruder with a screw diameter of 20 mm to 90 mm, preferably 26 mm to 75 cm; and the aspect ratio of the extruder is 36 to 44.

[0030] In the alloy preparation method described in the present invention, the operating process of the extruder includes: the temperature of the initial section (zones 1-3) is 50-205°C, the temperature of the middle section (zones 4-7) is 210-220°C, the temperature of the tail section (zones 8-9 or 8-10 or 8-11) is 220-260°C, and the head temperature is 220-270°C; the vacuum degree of the tail section is -0.6 to -0.98 MPa; and the screw speed is 200-400 rpm.

[0031] The purpose of using an initiator and azeotropic solvent in this formulation is to reduce the monomers produced during the shearing process of PMMA, allowing it to self-polymerize to reduce the residual amount. The remaining monomers can be removed by adding an azeotropic solvent.

[0032] The residual monomers in PMMA mainly include one or more of methyl methacrylate (MMA), methyl acrylate (MA), ethyl acrylate (EA), N,N-dimethylaminoethyl methacrylate (DM) and dimer of methyl methacrylate and N,N-dimethylaminoethyl methacrylate (DMMA), and the total amount is about 3000ppm to 3600ppm.

[0033] By using the method of the present invention, the residual monomer content in the material can be reduced to below 1000 ppm; without using the solution of the present invention, the residual monomer content in the material is above 3000 ppm.

[0034] The method of adding an azeotropic solvent in the present invention also reduces the amount of residual toner and additives in the mixing equipment due to the addition of liquid, making the material formulation more accurate and also promoting self-cleaning of the equipment. Therefore, it is also feasible to modify other plastics containing low-boiling-point components, such as PC, ABS, and PPO. When liquid additives are added during the production process for mixing, they are also considered to be within the scope of protection of the present invention. DETAILED DESCRIPTION

[0035] The following examples will further illustrate the solutions provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0036] The sample preparation method of the present invention is to dissolve the sample in acetone and stir to dissolve. The headspace vapor of the solution at 50°C is extracted and quantitatively analyzed by gas chromatography using either an internal or external standard method. The conditions are as follows: SPL inlet, temperature 250°C, split ratio 4:1; FID detector, temperature 250°C; a highly polar capillary chromatographic column, including but not limited to FFAP series, WAX series, PEG series, etc., with a column length of 15 to 30 m, a stationary phase thickness of 0.25 μm or 0.32 μm, and a diameter of 0.25 mm or 0.32 mm; and a heating program of initially holding at 70°C for 0.5 min, then increasing the temperature to 180°C at a rate of 2 to 10°C / min, and holding for 2 min.

[0037] Example 1

[0038] The raw materials of the modified PMMA composition are as follows: 55 parts of polymethyl methacrylate (Wanhua HD08L, the total residual monomer is 3245 ppm), 42.42 parts of toughening agent (ASA), 4.3 parts of color powder phthalocyanine blue BGS, 0.11 parts of lubricant pentaerythritol stearate, 0.05 parts of antioxidant (1076), 0.2 parts of release agent (paraffin), 1.5 parts of light stabilizer (UV-531), 0.16 parts of residual initiator (AIBN), and 0.5 parts of azeotropic solvent (water, conductivity 3 μC / cm).

[0039] Material melting method: screw diameter is 20 mm, extruder aspect ratio is 40, initial section (zones 1 to 3) temperature is 50, 180, 190°C; middle section (zones 4 to 7) temperature is 210, 210, 220, 220°C; tail section (8 to 10) temperature is 220, 220, 220°C, die head temperature is 220°C; tail section vacuum is -0.06 MPa; screw speed is 200 rpm; processing capacity is 20 kg / h.

[0040] The residual amount in the tested materials is shown in Table 1:

[0041] Table 1

[0042] MMA MA EA DM DMMA sum Residual amount ppm 633 25 78 120 56 912

[0043] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 2:

[0044] Table 2

[0045] Pentaerythritol stearate UV-531 Additive content g 0.105 1.47 Remaining additives% 95.45 98

[0046] Example 2

[0047] The raw materials of the modified PMMA composition are: 65 parts of polymethyl methacrylate (Wanhua HD03, the total residual monomer is 2013 ppm), 30.22 parts of toughening agent (ABS), 3.3 parts of color powder carbon black, 0.23 parts of lubricant polyethylene glycol 4000, 0.13 parts of antioxidant (H3311), 0.07 parts of release agent (stearic acid), 0.53 parts of light stabilizer (UV-360), 0.12 parts of residual initiator (BPO), and 0.4 parts of azeotropic solvent (ethanol).

[0048] Material melting method: screw diameter is 35mm, extruder aspect ratio is 40, initial section (zones 1-3) temperature is 80, 180, 200°C; middle section (zones 4-7) temperature is 210, 210, 215, 215°C; tail section (8-10) temperature is 220, 230, 230°C, die head temperature is 235°C; tail section vacuum is -0.07MPa; screw speed is 270rpm; processing capacity is 35kg / h.

[0049] The residual amount in the tested materials is shown in Table 3:

[0050] Table 3

[0051]

[0052]

[0053] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 4:

[0054] Table 4

[0055] polyethylene glycol 4000 UV-360 Additive content g 0.227 0.51 Remaining additives% 98.69 96.22

[0056] Example 3

[0057] The raw materials of the modified PMMA composition are: 70 parts of polymethyl methacrylate (Wanhua HD04, the total residual monomer is 1266 ppm), 26.02 parts of toughening agent (MBS), 0.16 parts of color powder iron oxide black, 0.33 parts of lubricant polyethylene glycol 6000, 0.22 parts of antioxidant (AO3352), 0.1 parts of release agent (hexadecanoic acid), 0.35 parts of light stabilizer (P4808NA), 0.08 parts of residual initiator (HMPP), and 0.3 parts of azeotropic solvent (isopropyl alcohol).

[0058] Material melting method: screw diameter is 50mm, extruder aspect ratio is 36, initial section (zones 1-3) temperature is 100, 200, 200℃; middle section (zones 4-7) temperature is 210, 215, 220, 220℃; tail section (8-9) temperature is 230, 240℃, die head temperature is 250℃; tail section vacuum is -0.08MPa; screw speed is 300rpm; processing capacity is 320kg / h.

[0059] The residual amount in the tested materials is shown in Table 5:

[0060] Table 5

[0061] MMA MA EA DM DMMA sum Residual amount ppm 502 35 22 87 66 712

[0062] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 6:

[0063] Table 6

[0064]

[0065]

[0066] Example 4

[0067] The raw materials of the modified PMMA composition are: 77 parts of polymethyl methacrylate (Wanhua HD01, the total residual monomer is 2896 ppm), 20.31 parts of toughening agent (SBS), 1.4 parts of color powder 4-(2-methylbutenyl) benzoic acid, 0.42 parts of lubricant polyethylene wax, 0.41 parts of antioxidant (1010), 0.05 parts of release agent (octadecyl alcohol), 0.15 parts of light stabilizer (4069), 0.06 parts of residual initiator (DMPA), and 0.2 parts of azeotropic solvent (methanol).

[0068] Material melting method: the extruder screw diameter is 75 mm, the aspect ratio is 44, the initial section (zones 1 to 3) temperatures are 120, 200, and 205°C; the middle section (zones 4 to 7) temperatures are 210, 215, 220, and 220°C; the tail section (8 to 11) temperatures are 230, 240, 250, and 260°C, and the die head temperature is 260°C; the tail section vacuum is -0.095 MPa; the screw speed is 250 rpm; and the processing capacity is 600 kg / h.

[0069] The residual amount in the tested materials is shown in Table 7 below:

[0070] Table 7

[0071] MMA MA EA DM DMMA sum Residual amount ppm 603 67 23 59 89 841

[0072] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 8:

[0073] Table 8

[0074] Octadecanol 4069 Additive content g 0.04 0.135 Remaining additives% 80 90

[0075] Example 5

[0076] Modified PMMA composition ingredients: 83.88 parts of polymethyl methacrylate (Wanhua HD01, total residual monomer content 2896 ppm), 14 parts of toughening agent (ASA), 2.6 parts of red iron oxide toner, 0.48 parts of pentaerythritol stearate lubricant, 0.50 parts of antioxidant (hydroquinone), 0.03 parts of mold release agent (dimethyl silicone oil), 0.8 parts of light stabilizer (UV-531), 0.1 parts of residual initiator (DCP), and 0.1 parts of azeotropic solvent (n-butanol).

[0077] Material melting method: extruder screw diameter is 90mm, aspect ratio is 36, initial section (zones 1-3) temperature is 150, 200, 200°C; middle section (zones 4-7) temperature is 210, 210, 220, 220°C; tail section (8-10) temperature is 240, 260, 260°C, die head temperature is 270°C; tail section vacuum is -0.09MPa; screw speed is 400rpm; processing capacity is 1000kg / h.

[0078] The residual amount in the tested materials is shown in Table 9:

[0079] Table 9

[0080] MMA MA EA DM DMMA sum Residual amount ppm 631 45 73 29 101 879

[0081] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 10:

[0082] Table 10

[0083] Pentaerythritol stearate UV-531 Additive content g 0.46 0.73 Remaining additives% 95.83 91.25

[0084] Comparative Example 1

[0085] In Example 1, the residual initiator and azeotropic solvent were replaced with HD08L (total residual monomer was 3245 ppm), i.e., 55.66 parts of HD08L, 0.00 parts of residual initiator (AIBN), and 0.00 parts of azeotropic solvent (water). The other formulations and material melting methods remained unchanged.

[0086] The residual amount in the tested materials is shown in Table 11:

[0087] Table 11

[0088] MMA MA EA DM DMMA sum Residual amount ppm 2567 437 221 179 45 3449

[0089] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 12:

[0090] Table 12

[0091] Pentaerythritol stearate UV-531 Additive content g 0.097 1.33 Remaining additives% 88.18 88.67

[0092] Comparative Example 2

[0093] In Example 1, the residual initiator was replaced with HD08L (total residual monomer was 3245 ppm), i.e., 55.16 parts of HD08L, 0.00 parts of residual initiator (AIBN), and 0.50 parts of azeotropic solvent (water, conductivity 32 μC / cm). The other formulations and material melting methods remained unchanged.

[0094] The residual amounts in the tested materials are as follows13:

[0095] Table 13

[0096] MMA MA EA DM DMMA sum Residual amount ppm 1700 250 162 102 22 2236

[0097] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 14:

[0098] Table 14

[0099] Pentaerythritol stearate UV-531 Additive content g 0.105 1.43 Remaining additives% 95.45 95.33

[0100] Comparative Example 3

[0101] In Example 1, the residual initiator was replaced with HD08L (total residual monomer was 3245 ppm), i.e., 55.50 parts of HD08L, 0.16 parts of residual initiator (AIBN), and 0.00 parts of azeotropic solvent (pure water). The other formulations and material melting methods remained unchanged.

[0102] The residual amount in the tested materials is shown in Table 15 below:

[0103] Table 15

[0104] MMA MA EA DM DMMA sum Residual amount ppm 820 134 89 68 35 1146

[0105] The content of single-component additives that are not easily deteriorated by heat in the measured materials is shown in Table 16:

[0106] Table 16

[0107] Pentaerythritol stearate UV-531 Additive content g 0.096 1.30 Remaining additives% 86.36 86.67

[0108] As can be seen from the above examples and comparative examples, the addition of an initiator and an azeotropic solvent results in lower residual monomer content than in the solution without initiator and residual solvent. The residual rate of single-component additives, which are less susceptible to thermal deterioration, is higher in the product with the addition of an azeotropic solvent than in the product without. This demonstrates that the addition of solvents removes residual powdered additives that adhere to the inner walls of the equipment, providing a self-cleaning function and bringing the additive content in the product closer to the intended resin value. This demonstrates the feasibility of the present invention.

Claims

1. A composition for preparing a modified polymethyl methacrylate alloy, comprising the following components in parts by mass: 55 to 83.88 parts of polymethyl methacrylate substrate, preferably 65 to 77 parts; 14.00 to 42.42 parts of toughening agent, preferably 20.31 to 30.22 parts; Color powder 0.06 to 3.3 parts, preferably 0.16 to 2.6 parts; 0.11 to 0.48 parts of lubricant, preferably 0.23 to 0.42 parts; 0.05-0.50 parts of antioxidant, preferably 0.13-0.41 parts; 0.03-0.2 parts of release agent, preferably 0.05-0.1 parts; 0.15 to 1.5 parts of light stabilizer, preferably 0.35 to 0.8 parts; 0.05 to 0.16 parts of residual initiator, preferably 0.06 to 0.12 parts; The amount of the residue azeotropic solvent is 0.1 to 0.5 parts, preferably 0.06 to 0.12 parts.

2. The composition according to claim 1, characterized in that The viscosity-average molecular weight of the polymethyl methacrylate substrate is 80,000 to 18,000, preferably 10,000 to 15,000; preferably, one or more of Wanhua Chemical products HD01, HD03, HD04, and HD08L.

3. The composition according to claim 1, characterized in that The toughening agent is a core-shell copolymer, preferably one or more of ABS, MBS, ASA, and SBS.

4. The composition according to claim 1, characterized in that The toner includes one or more of carbon black, 4-(2-methylbutenyl)benzoic acid, red iron oxide, black iron oxide, and phthalocyanine blue BGS.

5. The composition according to claim 1, characterized in that The lubricant includes one or more of polyethylene glycol 4000, polyethylene glycol 6000, polyethylene wax, and pentaerythritol stearate.

6. The composition according to claim 1, characterized in that The antioxidant includes one or more of 1076, H3311, AO3352, 1010, and hydroquinone; and / or the release agent includes one or more of paraffin, stearic acid, octadecyl alcohol, hexadecanoic acid, and dimethyl silicone oil.

7. The composition according to claim 1, characterized in that The light stabilizer includes one or more of UV-531, UV-360, 2,4-dihydroxybenzophenone, P4808NA, and 4069.

8. The composition according to claim 1, characterized in that The residue azeotropic solvent includes one or more of water, ethanol, isopropanol, methanol, and n-butanol.

9. A method for preparing a modified polymethyl methacrylate alloy, comprising the following steps: The composition according to any one of claims 1 to 8 is mixed, melt-extruded and pelletized in an extruder to obtain a finished product.

10. The method according to claim 9, characterized in that The extruder is a twin-screw extruder with a screw diameter of 20 mm to 90 mm, preferably 26 mm to 75 cm; the extruder aspect ratio is 36 to 44; the operating process of the extruder includes: an initial section temperature of 50 to 205° C., a middle section temperature of 210 to 220° C., a tail section temperature of 220 to 260° C., and a die head temperature of 220 to 270° C.; a tail section vacuum degree of -0.6 to -0.98 MPa; and a screw speed of 200 to 400 rpm.

Images