High-transparency colored polymethyl methacrylate and preparation method thereof

Abstract

The invention relates to the technical field of polymer synthesis, in particular to high-transparency colored polymethyl methacrylate and a preparation method thereof. The colored polymethyl methacrylate comprises the following components: a raw material for PMMA polymerization and a coloring auxiliary material, wherein the coloring auxiliary material is one or more of quinacridone dye, dioxazine pigment, perylene pigment, picene ketone dye, complex dye and anthraquinone dye; the coloring auxiliary material accounts for no more than 0.1% of the mass of the PMMA polymerization raw material. The prepared colored polymethyl methacrylate can obtain rich colors under the condition of keeping high light transmittance, and the preparation process is stable and suitable for batch production.

Description

Technical field:

[0001] The invention relates to the technical field of polymer synthesis, and in particular to a high-transparency colored polymethyl methacrylate and a preparation method thereof. Background technology:

[0002] As an engineering material with excellent comprehensive performance, polymethyl methacrylate (PMMA) has a light transmittance and high gloss comparable to glass, making it a perfect choice for design applications in civil or commercial fields. There are two common methods for coloring resin materials: external coloring and internal coloring. The external coloring method is also called the surface coloring method. The molded resin is impregnated, sprayed, polished, etc. to form pearlescent, piano paint and other effects on the resin surface; the internal coloring method is also called the overall coloring method. The colorant and resin are physically blended to achieve uniform coloring from the inside to the outside. The external coloring method has high production costs, complex processes, low efficiency, and serious harm to the environment and human body. The research and development focus has turned to spray-free internal coloring alloy materials.

[0003] Industrially produced PMMA molding materials have high transparency and are often melt-blended with resins such as ABS, PC, and PP to obtain spray-free alloy materials with transparency, glossiness, and excellent comprehensive performance, such as the HAM series PMMA / ABS alloy products prepared by Kumho Sunlight using the internal coloring method. Using PMMA as a transparent modifier will lose the excellent light transmission performance of PMMA. Using the internal coloring method, it is also difficult to achieve a high transparency when PMMA has a coloring effect. Mitsubishi Chemical Corporation of Japan (CN112166467 A) uses a twin-shaft extruder to mix transparent PMMA with dyes through the internal coloring method. The resulting colored resin composition has a total light transmittance of no more than 18% at a 2mm optical path.

[0004] With existing technical means, when blending or dyeing resins, if the modified resin or additive has poor compatibility with the base resin and poor dispersion stability, it may lead to problems such as uneven color of the alloy material, large color deviation, weak coloring and performance loss, thus affecting subsequent processing. Summary of the invention:

[0005] The technical problem to be solved by the present invention is to provide a highly transparent colored polymethyl methacrylate and a preparation method thereof. The invention realizes that the prepared colored polymethyl methacrylate obtains rich colors while maintaining high light transmittance, and the preparation process is stable and suitable for mass production. The existing internal coloring method overcomes the deficiency that it is difficult to achieve PMMA with a coloring effect and high transparency.

[0006] The technical solution adopted by the present invention is: a high-transparency colored polymethyl methacrylate, comprising the following components: raw materials for PMMA polymerization, coloring auxiliary materials, the coloring auxiliary materials are one or more of quinacridone dyes, dioxazine pigments, perylene pigments, chloranone dyes, complex dyes, and anthraquinone dyes; the coloring auxiliary materials account for no more than 0.1% of the mass percentage of the raw materials for PMMA polymerization.

[0007] Furthermore, the raw materials for PMMA polymerization are methyl methacrylate with a mass fraction of not less than 50% and acrylic acid ester monomers or styrene with a mass fraction of not more than 50%.

[0008] Furthermore, the raw materials for PMMA polymerization are methyl methacrylate with a mass fraction of not less than 70% and acrylic acid ester monomers or styrene with a mass fraction of not more than 30%.

[0009] Furthermore, the coloring auxiliary material is one or more of dioxazine pigments, chloranone dyes, and anthraquinone dyes.

[0010] Furthermore, the mass percentage of the coloring auxiliary material in the raw material for PMMA polymerization does not exceed 0.01%.

[0011] A method for preparing colored polymethyl methacrylate with high transparency, the method comprising the following steps: fully mixing and uniformly dispersing a coloring auxiliary material with a raw material for PMMA polymerization and an auxiliary agent for PMMA polymerization under stirring in a polymerization and molding device with continuous working conditions, and obtaining a colored polymethyl methacrylate product with high transparency through free radical polymerization and extrusion molding; the auxiliary agent for PMMA polymerization includes an initiator and a molecular weight regulator.

[0012] Furthermore, the polymerization and molding device with continuous working conditions includes a raw material preparation unit, a polymerization unit, a devolatilization extrusion unit and a granulation drying unit.

[0013] Furthermore, the PMMA polymerization auxiliary agent also includes a solvent.

[0014] Furthermore, the PMMA polymerization auxiliary agent also includes an antioxidant and an ultraviolet absorber.

[0015] The beneficial effects of the present invention are as follows: by selecting organic dyes or organic pigments that have little influence on the PMMA polymerization reaction, the organic dyes or organic pigments are fully mixed and uniformly dispersed in the raw materials for PMMA polymerization in a polymerization and molding device with continuous working conditions; through continuous polymerization and extrusion molding, the preparation process is stable and suitable for mass production; the obtained polymethyl methacrylate has rich colors with high saturation and high total light transmittance. Specific implementation method:

[0016] Example 1

[0017] A 5L / h continuous polymerization and molding device is used to quantitatively weigh the raw materials for PMMA polymerization. According to the mass fraction, the raw materials for PMMA polymerization include 95% methyl methacrylate, 5% methyl acrylate, 0.03% initiator and 0.09% molecular weight regulator. Toluene is used as a solvent, accounting for 25% of the raw materials for PMMA polymerization. According to the amount of raw materials for PMMA polymerization, 0.1% anthraquinone purple dye is added, and after uniform mixing, solution polymerization is carried out. After devolatilization, extrusion, water-cooling drawing, granulation and drying, high-transparency colored polymethyl methacrylate is obtained.

[0018] Example 2

[0019] A 3L / h continuous polymerization and molding device is used to quantitatively weigh the raw materials for PMMA polymerization. According to the mass fraction, the raw materials for PMMA polymerization include 96% methyl methacrylate, 4% methyl acrylate, 0.04% initiator and 0.12% molecular weight regulator. According to the amount of raw materials for PMMA polymerization, 0.1% of oxadiazole red dye is added in proportion, and after uniform mixing, bulk polymerization is carried out. After devolatilization, extrusion, water-cooling drawing, granulation and drying, high-transparency colored polymethyl methacrylate is obtained.

[0020] Example 3

[0021] A 5L / h continuous polymerization and molding device is used to quantitatively weigh the raw materials for PMMA polymerization. According to the mass fraction, the raw materials for PMMA polymerization include 95% methyl methacrylate, 5% methyl acrylate, 0.03% initiator and 0.09% molecular weight regulator of the raw materials for PMMA polymerization. Toluene is used as a solvent, accounting for 25% of the raw materials for PMMA polymerization. According to the amount of raw materials for PMMA polymerization, 0.01% anthraquinone purple dye is added, and after uniform mixing, solution polymerization is carried out. After devolatilization, extrusion, water-cooling drawing, granulation and drying, high-transparency colored polymethyl methacrylate is obtained.

[0022] Example 4

[0023] A 3L / h continuous polymerization and molding device is used to quantitatively weigh the raw materials for PMMA polymerization. According to the mass fraction, the raw materials for PMMA polymerization include 96% methyl methacrylate, 4% methyl acrylate, 0.04% initiator and 0.12% molecular weight regulator. According to the amount of raw materials for PMMA polymerization, 0.01% dioxazine purple dye is added in proportion, and after uniform mixing, bulk polymerization is carried out. After devolatilization, extrusion, water-cooling drawing, granulation and drying, high-transparency colored polymethyl methacrylate is obtained.

[0024] Example 5

[0025] A 3L / h continuous polymerization and molding device is used to quantitatively weigh the raw materials for PMMA polymerization. According to the mass fraction, the raw materials for PMMA polymerization include 75% methyl methacrylate, 25% styrene, 0.07% initiator and 0.15% molecular weight regulator. According to the amount of raw materials for PMMA polymerization, 0.1% of oxadiazole red dye is added in proportion, and after uniform mixing, bulk polymerization is carried out. After devolatilization, extrusion, water-cooling drawing, granulation and drying, high-transparency colored polymethyl methacrylate is obtained.

[0026] The transmittance was measured according to GB / T 2410-2008 standard, and the values ​​of each component in the CIEL a×b×c color space were obtained. The measurement results are shown in Table 1.

[0027] Table 1 Specific Example Product Performance List

[0028]

[0029] As shown in Examples 1-5 above, the prepared colored polymethyl methacrylate has rich colors with high saturation, and the total light transmittance can reach more than 50%. The "high transparency" in the patent name of the present invention "A high-transparency colored polymethyl methacrylate and its preparation method" means that the total light transmittance reaches more than 50%.

[0030] It can be understood that the above specific description of the present invention is only used to illustrate the present invention and is not limited to the technical solutions described in the embodiments of the present invention. Those skilled in the art should understand that the present invention can still be modified or replaced by equivalents to achieve the same technical effects; as long as the use requirements are met, they are within the protection scope of the present invention.

Claims

1. A highly transparent colored polymethyl methacrylate, characterized in that: The invention comprises the following components: raw materials for PMMA polymerization and coloring auxiliary materials, wherein the coloring auxiliary materials are one or more of quinacridone dyes, dioxazine pigments, perylene pigments, oxadiazole dyes, complex dyes and anthraquinone dyes; and the coloring auxiliary materials account for no more than 0.1% of the mass percentage of the raw materials for PMMA polymerization.

2. The high-transparency colored polymethyl methacrylate according to claim 1, characterized in that: The raw materials for PMMA polymerization are methyl methacrylate with a mass fraction of not less than 50% and acrylic acid ester monomers or styrene with a mass fraction of not more than 50%.

3. The highly transparent colored polymethyl methacrylate according to claim 2, characterized in that: The raw materials for PMMA polymerization are methyl methacrylate with a mass fraction of not less than 70% and acrylic acid ester monomers or styrene with a mass fraction of not more than 30%.

4. The high-transparency colored polymethyl methacrylate according to claim 1, characterized in that: The coloring auxiliary material is one or more of dioxazine pigments, chloranone dyes and anthraquinone dyes.

5. The highly transparent colored polymethyl methacrylate according to claim 1, characterized in that: The mass percentage of the coloring auxiliary material in the raw material for PMMA polymerization does not exceed 0.01%.

6. A method for preparing highly transparent colored polymethyl methacrylate according to claim 1, characterized in that: The method comprises the following steps: fully mixing and uniformly dispersing the coloring auxiliary material with the raw material for PMMA polymerization and the auxiliary agent for PMMA polymerization under stirring in a polymerization and molding device with continuous working conditions, and obtaining a high-transparency colored polymethyl methacrylate finished product through free radical polymerization and extrusion molding; the above-mentioned auxiliary agent for PMMA polymerization includes an initiator and a molecular weight regulator.

7. The method for preparing highly transparent colored polymethyl methacrylate according to claim 6, characterized in that: The polymerization and molding device with continuous working conditions comprises a raw material preparation unit, a polymerization unit, a devolatilization extrusion unit and a granulation drying unit.

8. The method for preparing colored polymethyl methacrylate with high transparency according to claim 6, characterized in that: The PMMA polymerization auxiliary agent also includes a solvent.

9. The method for preparing colored polymethyl methacrylate with high transparency according to claim 6, characterized in that: The PMMA polymerization auxiliary agent also includes an antioxidant and an ultraviolet absorber.

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