High-transparency antistatic PMMA composite material and preparation method thereof

Abstract

The invention discloses a high-transparency antistatic PMMA (polymethyl methacrylate) composite material which comprises the following components in parts by weight: 97.0-98.5 parts of a PMMA matrix; 1.5-2.0 parts by weight of a compound antistatic system, which is composed of the following components: 0.8-1.5 parts by weight of a cationic antistatic agent; 0.5 to 1.0 part by weight of a nonionic dispersion carrier; 0.1 to 0.3 part by weight of a conductive polymer auxiliary agent; the compound antistatic system forms an ion-electron double-conduction interpenetrating network through a carrier preloading-low temperature protection-gradient temperature control process. The invention belongs to the technical field of PMMA (polymethyl methacrylate) preparation, and particularly provides a high-transparency antistatic PMMA composite material and a preparation method thereof, which are used for solving the problems of contradiction between conductive filler and light transmission, poor thermal stability of a micromolecule antistatic agent and nonuniform dispersion of a conductive polymer.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of PMMA preparation, and particularly relates to a high-transparency anti-static PMMA composite material and a preparation method thereof. BACKGROUND

[0002] Poly (methyl methacrylate) (PMMA) is widely used in optical display devices due to its light transmittance > 92%. However, PMMA has inherent volume resistivity > 10 15 Ω, which is easy to accumulate static electricity, resulting in problems such as dust adsorption and electronic component breakdown. Current anti-static modification technologies have the following defects:

[0003] 1. Conductive fillers (such as carbon nanotubes) need to be added in a high amount, such as > 3.0 wt%, to achieve a surface resistance of 10 6 ~ 10 8 Ω, but this leads to a decrease in light transmittance to ≤ 88% (for example, Mitsubishi Chemical SH001 product).

[0004] 2. Quaternary ammonium salt anti-static agents have a decomposition rate > 30% (verified by TG-DSC) when processed above 160℃, and migrate and precipitate, resulting in an effective period < 6 months (such as Sumitomo Chemical ACRYPLAS TM ), poor stability.

[0005] 3. PEDOT:PSS directly blended tends to agglomerate, causing uneven dispersion of conductive polymers. SUMMARY

[0006] In view of the above problems, the present application provides a high-transparency anti-static PMMA composite material and a preparation method thereof, which can solve the contradiction between conductive fillers and light transmittance, the poor thermal stability of small-molecule anti-static agents, and the uneven dispersion of conductive polymers.

[0007] The technical scheme adopted by the present application is as follows:

[0008] In one aspect, the present application discloses a high-transparency anti-static PMMA composite material, which comprises, by weight:

[0009] PMMA matrix: 97.0-98.5 parts by weight;

[0010] Compound anti-static system: 1.5-2.0 parts by weight, which is composed of:

[0011] Cationic anti-static agent: 0.8-1.5 parts by weight;

[0012] Non-ionic dispersion carrier: 0.5-1.0 parts by weight;

[0013] Conductive polymer additive: 0.1-0.3 parts by weight;

[0014] The complex antistatic system forms an ion-electron double-conductive interpenetrating network through carrier preloading-low temperature active protection-gradient temperature control process.

[0015] Preferably, the cationic antistatic agent is selected as dioctadecyldimethylammonium chloride (DODMAC), the non-ionic dispersion carrier is selected as polyethylene glycol stearate (PEG-400S), and the conductive polymer additive is selected as PEDOT:PSS in solid content.

[0016] Preferably, in the complex antistatic system, PEDOT:PSS is dispersed in the polyethylene glycol stearate carrier to form a continuous electron conductive skeleton, and dioctadecyldimethylammonium chloride is embedded in the gap of the skeleton to form an ion conductive channel, thereby forming an ion-electron double-conductive interpenetrating network.

[0017] Preferably, the PMMA matrix has a melt index of 2±0.5 g / 10 min (230℃ / 3.8 kg).

[0018] In another aspect, the application also discloses a preparation method of high-transparency antistatic PMMA composite material, comprising the following steps:

[0019] Step S1, pre-dispersing the conductive network carrier phase:

[0020] Mix PEG-400S and PEDOT:PSS nanodispersion liquid at 80±5℃ in an inert atmosphere, and stir at constant temperature for 30 min to construct an electron conductive skeleton;

[0021] Step S2, mixing the ion-type antistatic agent at low temperature:

[0022] After cooling to <50℃, add DODMAC and mix for 10 min, so that DODMAC is completely embedded in the gap of the electron conductive skeleton at low temperature to form an ion conductive channel;

[0023] Step S3, gradient temperature control blending by double screw:

[0024] Four-section interval temperature control is adopted:

[0025] In the first section, the temperature is controlled at 160±5℃ for PMMA melting;

[0026] In the second section, the temperature is controlled at 170±5℃ for PEG-400S / DODMAC / PEDOT:PSS three-phase synergistic dispersion;

[0027] In the third section, the temperature is controlled at 155±3℃ for inhibiting thermal decomposition of DODMAC;

[0028] In the die, the temperature is controlled at 150±2℃ for precise sizing.

[0029] Preferably, in the step S3, the high temperature shearing of the two zones 170℃ triggers the ion antistatic agent to form an interpenetrating network structure with the conductive polymer additive, so that the surface resistance of the composite material is reduced to 10 9 11 Ω.

[0030] The beneficial effects achieved by the above-mentioned scheme are as follows:

[0031] 1. The ion-electron dual-conductive interpenetrating network reduces the surface resistance while increasing the light transmittance, breaking through the contradiction between antistatic and light transmittance, with reduced total additive amount.

[0032] 2. The low-temperature protection process combined with three-zone temperature control inhibits the thermal decomposition of DODMAC.

[0033] 3. The PEG-400S carrier pre-dispersion reduces the aggregation rate of PEDOT:PSS, thereby eliminating the dispersion defects of the conductive network. DETAILED DESCRIPTION

[0034] The technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] Embodiment 1

[0036] The present application is a kind of high transparent antistatic PMMA composite material, comprising:

[0037] Formulation: PMMA 97.7wt%+DODMAC 1.0%+PEG-400S 0.8%+PEDOT:PSS (solid content 0.2%);

[0038] The process includes:

[0039] S1, pre-disperse the conductive network carrier phase:

[0040] Mix PEG-400S and PEDOT:PSS nanodispersion at 82℃ in an inert atmosphere, constant temperature stirring for 30min, to build an electronic conductive skeleton;

[0041] Step S2, low-temperature blending of ion antistatic agent:

[0042] After cooling to 45℃, add DODMAC, mix for 10min, and DODMAC is completely embedded in the gap between the electronic conductive skeleton, forming an ion conductive channel; ​

[0043] Step S3, double screw gradient temperature control blending:

[0044] Four-section interval temperature control is adopted:

[0045] Zone 1, temperature control at 160℃, for PMMA melting;

[0046] Zone 2, temperature control at 172℃ / 230s -1 , for PEG-400S / DODMAC / PEDOT:PSS three-phase synergistic dispersion;

[0047] Zone 3, temperature control at 155℃, for inhibiting DODMAC thermal decomposition;

[0048] Die, temperature control at 150℃, for precise shaping.

[0049] Through the above materials and processes, the high-transparency antistatic PMMA composite material is prepared, and the performance thereof is: surface resistance 3.2×10 10 Ω, light transmittance 92.1%, haze 0.7%, heat distortion temperature 89℃.

[0050] It should be noted that in this paper, the term "includes", "contains" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or equipment.

[0051] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

[0052] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent process transformation using the content of the present application specification, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A highly transparent antistatic PMMA composite material, characterized in that: In parts by weight, it comprises: PMMA matrix: 97.0-98.5 parts by weight; Compound antistatic system: 1.5-2.0 parts by weight, composed of the following: 0.8-1.5 parts by weight of cationic antistatic agent; 0.5-1.0 parts by weight of nonionic dispersing carrier; 0.1 to 0.3 parts by weight of conductive polymer additive; The composite antistatic system forms an ion-electron dual-conducting interpenetrating network through a carrier preloading-low temperature activation-gradient temperature control process.

2. The highly transparent antistatic PMMA composite material according to claim 1, characterized in that: The cationic antistatic agent is dioctadecyl dimethyl ammonium chloride (DODMAC), the nonionic dispersion carrier is polyethylene glycol stearate (PEG-400S), and the conductive polymer additive is PEDOT:PSS calculated by solid content.

3. The highly transparent antistatic PMMA composite material according to claim 2, characterized in that: In the composite antistatic system, PEDOT:PSS is dispersed in a polyethylene glycol stearate carrier to form a continuous electronic conductive skeleton, and dioctadecyldimethylammonium chloride is embedded in the gaps of the skeleton to form ion conduction channels, thereby constituting an ion-electron dual-conducting interpenetrating network.

4. The highly transparent antistatic PMMA composite material according to claim 1, characterized in that: The PMMA matrix melt index is 2±0.5 g / 10 min.

5. A method for preparing a highly transparent antistatic PMMA composite material according to any one of claims 2 to 4, characterized in that: The following steps are involved: Step S1, pre-dispersing the conductive network carrier phase: PEG-400S and PEDOT:PSS nanodispersion were mixed at 80 ± 5 °C under inert atmosphere and stirred at constant temperature for 30 min to construct the electronic conductive framework; Step S2, mixing ionic antistatic agent at low temperature: After cooling to <50°C, DODMAC is added and mixed for 10 minutes, so that DODMAC is completely embedded in the gaps of the electronic conductive skeleton at low temperature to form ion conduction channels; Step S3, twin-screw gradient temperature control blending: Four-stage temperature control: Zone 1, temperature controlled at 160±5℃, used for PMMA melting; Zone 2, temperature controlled at 170 ± 5 °C, is used for PEG-400S / DODMAC / PEDOT:PSS three-phase synergistic dispersion; Zone 3, temperature controlled at 155 ± 3 °C, is used to inhibit thermal decomposition of DODMAC; The die head temperature is controlled at 150±2℃ for precise shaping.

6. The method for preparing a highly transparent antistatic PMMA composite material according to claim 5, characterized in that: In step S3, the high temperature shear triggering ionic antistatic agent and conductive polymer additive in the second zone at 170°C forms an interpenetrating network structure, which reduces the surface resistance of the composite material to 10 9 ~10 11 Ω.