Abs base material for improving thermoforming properties

Abstract

The application discloses an ABS base material for improving hot forming performance, which comprises the following components: ABS resin 97-99 parts, antioxidant 0.4-1 part, lubricant 0.6-2 parts, wherein the antioxidant is a mixture of polyhydric hindered phenolic antioxidant and thioether antioxidant, and the mass ratio of the polyhydric hindered phenolic antioxidant to the thioether antioxidant is 1: (2-5). The application effectively inhibits the oxidative degradation reaction of the ABS resin in the hot forming process and improves the thermal stability of the material by adding the polyhydric hindered phenolic antioxidant and the thioether antioxidant in cooperation, and then mixing and melting extruding the pretreated ABS resin and the lubricant.

Description

Technical Field

[0001] This invention relates to the field of thermoplastic material production technology, and in particular to an ABS substrate with improved thermoforming properties. Background Technology

[0002] ABS resin (acrylonitrile-butadiene-styrene copolymer) is a thermoplastic engineering plastic with excellent comprehensive properties, including high strength, high toughness, good processability, and surface gloss. It is widely used in toys, electronics, and packaging containers. However, during thermoforming, ABS resin is susceptible to oxidative degradation caused by heat and oxygen, leading to molecular chain breakage, a decrease in molecular weight, and impaired material properties such as reduced melt strength and discoloration. Furthermore, insufficient flowability of ABS resin during thermoforming affects its ability to fill molds, resulting in defects such as short runs and weld lines. This limits its application in scenarios requiring high molding precision and performance. Summary of the Invention

[0003] To address the above shortcomings, the present invention adopts the following technical solution: An ABS substrate for improving thermoforming performance, comprising, by weight, the following components: 97-99 parts ABS resin, 0.4-1 parts antioxidant, and 0.6-2 parts lubricant, wherein the antioxidant is a mixture of multi-functional hindered phenolic antioxidant and thioether antioxidant, wherein the mass ratio of the multi-functional hindered phenolic antioxidant to the thioether antioxidant is 1:(2-5).

[0004] Multi-component hindered phenolic antioxidants contain two or more hindered phenolic units, each containing a phenolic hydroxyl group (-OH). Due to steric hindrance, the hydrogen atoms (H) on these hydroxyl groups readily detach from the molecular structure, becoming active hydrogen (AH). Compared to mono-component hindered phenols, multi-component hindered phenols can provide more active hydrogen. These active hydrogens can combine with peroxide radicals (ROO•), alkyl radicals, hydroxyl radicals, etc., to generate hydroperoxides and stable phenoxy radicals (ArO•), blocking the chain oxidation reaction and thus delaying the thermo-oxidative aging process of ABS resin. The reaction formula is as follows: ROO•+ AH → ROOH + ArO• (Formula 1) The combination of thioether antioxidants and multi-functional hindered phenolic antioxidants decomposes hydroperoxide (ROOH) into stable alcohol / ketone products, blocking the source of new free radicals. In addition, thioether antioxidants can also reduce some of the oxidized and deactivated phenolic radicals (ArO•) to active phenols (AH), reducing the consumption of multi-functional hindered phenolic antioxidants.

[0005] In a preferred embodiment, the multi-component hindered phenolic antioxidant is any one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), (1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (antioxidant 330), or 2,2'-methylenebis(6-tert-butyl-4-methylphenol (antioxidant 2246)).

[0006] In a preferred embodiment, the thioether antioxidant is any one of dilauryl thiodipropionate, 2,4-di(n-octylthiomethylene)-6-methylphenol, or pentaerythritol tetrakis(3-lauryl thiopropionate).

[0007] In a preferred embodiment, the lubricant is at least one of a fatty acid ester lubricant and an amide lubricant. Fatty acid ester lubricants have polarity matching with antioxidants, reducing the risk of lubricant encapsulation during mixing. When used synergistically with a multi-hindered phenol and thioether compound antioxidant system, they can improve the solution flow rate and the surface gloss of the product. Amide lubricants exhibit excellent stability at high temperatures, preventing antioxidant decomposition. They can also act as nucleating agents, refining grain size. When used synergistically with a multi-hindered phenol and thioether compound antioxidant system, they improve the mechanical properties of the product and broaden the processing temperature window.

[0008] Furthermore, the lubricant is at least one of pentaerythritol stearate, glyceryl stearate, butyl stearate, and N,N'-ethylene bis-stearamide.

[0009] In the above scheme, the preparation method of the substrate includes the following steps: S1 pretreatment of the antioxidant; S2 ABS resin is dried at 80-100℃ for 2-4 hours. The ABS resin, pretreated antioxidant and lubricant are added to a high-speed mixer and mixed for 10-15 minutes at a speed of 300-600r / min to ensure that the components are fully mixed and uniform. Then, the mixture is added to a twin-screw extruder for melt blending and extrusion.

[0010] S3 processes the extruded melt by water cooling and air drying, and then cuts it into pellets using a pelletizer.

[0011] In this scheme, silica nanoparticles can be used to pretreat the antioxidant in S1 to improve its migration resistance, dispersion uniformity, and long-lasting effect. In a preferred embodiment, the pretreatment includes the following steps: S11 Dissolve the multi-functional hindered phenolic antioxidant and the thioether antioxidant in anhydrous ethanol until a homogeneous solution is formed; S12 involves uniformly dispersing silica nanoparticles in ethanol to obtain a suspension. The solution obtained in S11 is then slowly added to the silica nanoparticle suspension. After stirring for 3-4 hours, the mixture is centrifuged, washed, and dried to complete the pretreatment and obtain antioxidant particles.

[0012] In a preferred embodiment, the silica nanoparticles in S12 are ≤50nm, and the mass ratio of the silica nanoparticles to the antioxidant is 10:(2-3).

[0013] The beneficial effects of this invention are as follows: 1. This invention effectively inhibits the oxidative degradation reaction of ABS resin during thermoforming by adding multi-component hindered phenolic and thioether antioxidants, thereby improving the thermal stability of the material.

[0014] 2. This invention provides long-lasting protection below 150°C through multi-component hindered phenolic antioxidants, and decomposes hydrogen peroxide at high temperatures with thioether antioxidants, reducing the oxidation induction period. This antioxidant compound system can cover a wider temperature range and meet the antioxidant requirements of the entire process from melting to cooling in thermoforming.

[0015] 3. In this invention, antioxidants are first adsorbed and complexed with silica nanoparticles, and then mixed with ABS resin and lubricant for melt co-extrusion. This results in uniform antioxidant loading, improved migration resistance, and reduced the situation where lubricant encapsulation or uneven melting during the mixing process leads to agglomeration, which affects molding performance. Detailed Implementation

[0016] The present invention will be further illustrated below with reference to the embodiments, the purpose of which is to better understand the content of the present invention and to demonstrate the essential features of the present invention. Therefore, the examples given should not be regarded as a limitation on the scope of protection of the present invention.

[0017] All quantities mentioned in this application refer to weight quantities. Example

[0018] S1 Weigh 0.17 parts of antioxidant 2246 and 0.83 parts of pentaerythritol tetra(3-lauryl thiopropionate) and dissolve them in anhydrous ethanol to form a homogeneous solution. Disperse 5 parts of silica nanoparticles (CAS code: 60676-86-0) uniformly in anhydrous ethanol to obtain a suspension. Slowly add the antioxidant solution to the silica nanoparticle suspension, stir for 3-4 hours, and then centrifuge, wash, and dry to obtain antioxidant particles for later use. S2 dried 97 parts of ABS resin at 100℃ for 2 hours, added ABS resin, pretreated antioxidant and lubricant to a high-speed mixer, and mixed for 10 minutes at a speed of 300 r / min to ensure that all components were fully mixed and uniform. Then, the mixture was added to a twin-screw extruder for melt blending and extrusion.

[0019] S3 processes the extruded melt by water cooling and air drying, and then cuts it into pellets using a pelletizer. Example

[0020] S1 Weigh 0.18 parts of antioxidant 1010 and 0.62 parts of dilauryl thiodipropionate and dissolve them in anhydrous ethanol to form a homogeneous solution. Disperse 2.7 parts of silica nanoparticles uniformly in anhydrous ethanol to obtain a suspension. Slowly add the antioxidant solution to the silica nanoparticle suspension, stir for 3-4 hours, and then centrifuge, wash, and dry to obtain antioxidant particles for later use. S2 dried 98 parts of ABS resin at 80°C for 3 hours, added the ABS resin, pretreated antioxidant and lubricant to a high-speed mixer, and mixed for 15 minutes at a speed of 400 r / min to ensure that all components were fully mixed and uniform. Then, the mixture was added to a twin-screw extruder for melt blending and extrusion.

[0021] S3 processes the extruded melt by water cooling and air drying, and then cuts it into pellets using a pelletizer. Example

[0022] S1 Weigh 0.17 parts of antioxidant 2246 and 0.83 parts of dilauryl thiodipropionate and dissolve them in anhydrous ethanol to form a uniform solution. Disperse 5 parts of silica nanoparticles uniformly in anhydrous ethanol to obtain a suspension. Slowly add the antioxidant solution to the silica nanoparticle suspension. After stirring for 3-4 hours, centrifuge, wash, and dry to obtain antioxidant particles for later use. S2 dried 97 parts of ABS resin at 90°C for 2 hours, added the ABS resin, pretreated antioxidant and lubricant to a high-speed mixer, and mixed for 12 minutes at a speed of 500 r / min to ensure that all components were fully mixed and uniform. Then, the mixture was added to a twin-screw extruder for melt blending and extrusion.

[0023] S3 processes the extruded melt by water cooling and air drying, and then cuts it into pellets using a pelletizer.

[0024] Comparative Examples 1-3 were prepared using the same methods as Example 2, but the raw materials differed as shown in Table 1.

[0025] Table 1 Components of each sample

[0026] The masterbatches prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to the following statistical analysis and testing: 1. According to GB / T 3682-2018, test the melt mass flow rate under different loads (2.16 kg and 5 kg) at the same temperature (220℃), and calculate the rate of change of melt mass flow rate; 2. Prepare specimens according to ISO 294-1. 1) Statistical molding pass rate: Samples with obvious defects such as insufficient material or weld lines are considered unqualified, and the molding pass rate is calculated. 2) Test tensile strength according to ISO 527 standard; test flexural strength according to ISO 178 standard; test notched impact strength according to ISO 180 standard.

[0027] Table 2 Test Results

[0028] As shown in Table 2, the appearance qualification rate of the molded samples of Examples 1-3 is significantly better than that of Comparative Examples 1-3. At 220°C, the change rate of melt flow rate of Examples 1-3 is more than 20% lower than that of ABS resin without antioxidant (Comparative Example 1), indicating that the antioxidant significantly slows down the thermal decomposition rate of ABS resin. Meanwhile, the mechanical properties of the samples, such as tensile strength, flexural strength and impact strength, are comparable to those of ABS resin without antioxidant and lubricant.

[0029] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0030] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An ABS substrate with improved thermoforming properties, characterized in that, The product comprises the following components by weight: 97-99 parts ABS resin, 0.4-1 parts antioxidant, and 0.6-2 parts lubricant. The antioxidant is a mixture of multi-functional hindered phenolic antioxidant and thioether antioxidant, with a mass ratio of 1:(2-5) for the multi-functional hindered phenolic antioxidant and thioether antioxidant.

2. The ABS substrate for improving thermoforming performance according to claim 1, characterized in that, The multi-component hindered phenolic antioxidant is any one of antioxidant 1010, antioxidant 330, and antioxidant 2246.

3. The ABS substrate for improving thermoforming performance according to claim 1, characterized in that, The thioether antioxidant is any one of dilauryl thiodipropionate, 2,4-di(n-octylthionyl)-6-methylphenol, or pentaerythritol tetra(3-lauryl thiopropionate).

4. The ABS substrate for improving thermoforming performance according to claim 1, characterized in that, The lubricant is at least one of fatty acid lubricants or amide lubricants.

5. The ABS substrate with improved thermoforming properties according to claim 4, characterized in that, The lubricant is at least one of pentaerythritol stearate, glyceryl stearate, butyl stearate, and N,N'-ethylene bis-stearamide.

6. The ABS substrate for improving thermoforming performance according to claim 1, characterized in that, Its preparation method includes the following steps: The antioxidant described in S1 undergoes nano-pretreatment; S2 ABS resin is dried at 80-100℃ for 2-4 hours. The ABS resin, pretreated antioxidant and lubricant are added to a high-speed mixer and mixed for 10-15 minutes at a speed of 300-600r / min to ensure that the components are fully mixed and uniform. Then, the mixture is added to a twin-screw extruder for melt blending and extrusion. 7.S3 After the extruded melt is cooled with water and air-dried, it is cut into pellets using a pelletizer.

8. The ABS substrate with improved thermoforming properties according to claim 6, characterized in that, Preprocessing in S1 includes the following steps: S11 Dissolve the multi-functional hindered phenolic antioxidant and the thioether antioxidant in anhydrous ethanol until a homogeneous solution is formed; S12 involves uniformly dispersing silica nanoparticles in ethanol to obtain a suspension. The solution obtained in S11 is then slowly added to the silica nanoparticle suspension. After stirring for 3-4 hours, the mixture is centrifuged, washed, and dried to complete the pretreatment and obtain antioxidant particles.

9. The ABS substrate with improved thermoforming properties according to claim 7, characterized in that, In step S12, the silica nanoparticles are ≤50nm, and the mass ratio of the silica nanoparticles to the antioxidant is 10:(2-3).

Images