A san / pctg alloy material and a preparation method and application thereof

Abstract

The application discloses a SAN / PCTG alloy material, which comprises the following components in parts by weight: SAN resin 20-60 parts, PCTG resin 30-50 parts, toughening agent 10-30 parts, and compatibility agent 0.2-5 parts, wherein the PCTG is a product obtained by using p-terephthalic acid (PTA), ethylene glycol (EG) and 1,4-cyclohexane dimethanol (CHDM) as three monomers and by using an ester exchange method for polycondensation. The SAN and the PCTG have good compatibility by introducing the PCTG into the SAN. The oil resistance, solvent resistance and stability of the obtained SAN are effectively enhanced by modifying the SAN with the PCTG in a specific content, and the comprehensive performance of the SAN is excellent.

Description

Technical Field

[0001] This invention relates to the field of engineering plastics technology, specifically to a SAN / PCTG alloy material, its preparation method, and its applications. Background Technology

[0002] Styrene-acrylonitrile copolymer (SAN) is obtained by suspension polymerization of acrylonitrile and styrene. Due to its inherent transparency, this resin is used to manufacture transparent plastic products and can be used alone in areas such as fans and cosmetic cases. Simultaneously, by blending with high-polymer powder, ABS resins of different specifications can be obtained for use in household appliances, automobiles, and electronic appliances.

[0003] PCTG, a copolyester, is a copolymer of terephthalic acid (PTA), ethylene glycol (EG), and 1,4-cyclohexanediethanol (CHDM). Based on the CHDM content, it can be divided into two types: PETG (CHDM < 50%) and PCTG (CHDM > 50%). This copolyester is a novel transparent engineering plastic with wide applications in household appliances, toys, packaging materials, and building tools. PCTG, due to its higher CHDM content, exhibits better toughness and therefore has a wider range of applications.

[0004] Essential oils are volatile aromatic substances extracted from aromatic plants or scent-producing animals. SAN resin has good solvent resistance, but due to its compatibility with similar substances, it has poor tolerance to plant essential oils used in aromatherapy devices and other fields. It is prone to swelling, and when combined with ABS resin composed of high-polymer powder, it is not only prone to swelling but also to significant yellowing, resulting in a deterioration in appearance. Summary of the Invention

[0005] To overcome the shortcomings or defects of the prior art, this invention proposes a SAN / PCTG alloy material, its preparation method, and its applications. This invention uses a SAN resin with high acrylonitrile content to form an alloy with PCTG, while selecting an acrylate rubber with a specific structure to obtain a SAN / PCTG alloy with good resistance to essential oils. The invention also provides a corresponding preparation method and applications.

[0006] This invention is achieved through the following technical solution:

[0007] A SAN / PCTG alloy material comprising the following components in parts by weight:

[0008]

[0009] The PCTG resin is a copolymer of terephthalic acid, ethylene glycol, and 1,4-cyclohexanediethanol.

[0010] The inventors have creatively discovered that mixing SAN resin with PCTG resin to form a SAN / PCTG alloy can improve the oil and chemical resistance of SAN resin. While the semi-crystalline ABS / PBT system is a known alloy system with good solvent resistance, it still exhibits significant swelling when used to manufacture containers for essential oils, failing to meet usage requirements. This invention utilizes an acrylate-toughened SAN / PCTG alloy system, which demonstrates superior solvent resistance compared to the ABS / PBT alloy system.

[0011] As a preferred embodiment, in the SAN resin, based on the total mass of the SAN resin, the mass content of acrylonitrile is greater than or equal to 25%, and preferably, the mass content of acrylonitrile is 32-35%.

[0012] As a preferred embodiment, the mass percentage of 1,4-cyclohexanediethanol in the PCTG resin is greater than 50% of the total mass of the PCTG resin. The melt index of PCTG is 10-30 g / 10 min at 220°C and 10 kg. This invention does not impose any particular limitation on the melt index of PCTG.

[0013] As a preferred embodiment, the toughening agent is an acrylate toughening agent, and more preferably, the toughening agent is an acrylonitrile-butyl acrylate-styrene polymer.

[0014] Acrylic esters, used as toughening agents, can copolymerize with styrene and acrylonitrile in SAN resin during blending. Compared to SAN / PCTG composites without acrylate toughening agents, the addition of acrylate toughening agents reduces polymer molecular polarity, makes the chain segments more flexible, increases flowability, and facilitates processing. However, as the acrylate content increases, the acrylonitrile mass fraction decreases, leading to a decrease in the oil and chemical resistance of the SAN / PCTG alloy material. Simultaneously, as the acrylate mass fraction increases, properties such as strength and transparency slightly improve, while the softening temperature decreases. Therefore, for SAN resins with specific performance requirements, the amount of acrylate toughening agent added must be appropriate to ensure that the application requirements are met. Furthermore, the inventors of this invention have also discovered that when acrylates are incorporated into SAN resin, the appearance of the SAN / PCTG alloy material can be significantly improved, with a decrease in the yellow index and an increase in whiteness.

[0015] As a preferred embodiment, the compatibilizer is a styrene-N-phenylmaleimide-anhydrous maleic anhydride copolymer.

[0016] As a preferred embodiment, it may also include 0.2-2 parts of an antioxidant, wherein the antioxidant is at least one of a copper salt complex antioxidant, a hindered phenolic antioxidant, and a phosphite antioxidant.

[0017] As a preferred embodiment, it may also include a lubricant, which may be one or more of ethylene bis-stearamide, pentaerythritol stearate, or oleamide.

[0018] In the SAN / PCTG alloy material of this invention, the sum of the masses of SAN and PCTG resins is not less than 50 wt%.

[0019] This invention is achieved through the following technical solution:

[0020] A method for preparing a SAN / PCTG alloy material includes the following steps:

[0021] S1: Weigh out each component according to the ratio, premix them, and obtain the premix;

[0022] S2: The premix from step S1 is fed into an extruder for melt blending and extrusion granulation to obtain the SAN / PCTG alloy material.

[0023] As a preferred embodiment, the extruder is further described as a twin-screw extruder, wherein the length-to-diameter ratio of the screw is (40-48):1, the screw speed is 250-600 r / min, and the temperatures of each screw barrel from the feed port to the die head are 160℃-180℃, 180℃-220℃, 200℃-240℃, 220℃-240℃, 220℃-250℃, 220℃-250℃, 220℃-240℃, 220℃-240℃, 200℃-240℃, and 200℃-240℃, respectively. The feeding speed is 500 kg / h-1500 kg / h, and the vacuum degree is (-0.1)-0 MPa.

[0024] The present invention also provides the application of the above-mentioned SAN / PCTG alloy material in oil-resistant packaging materials, such as skin care product packaging, beauty oil packaging, essential oil packaging, etc.

[0025] The present invention has the following advantages and effects compared with the prior art:

[0026] This invention provides a SAN / PCTG alloy material by introducing PCTG into SAN, which exhibits good compatibility with PCTG. Furthermore, by modifying SAN with a specific content of PCTG, the resulting SAN exhibits significantly enhanced oil resistance, solvent resistance, and stability, resulting in excellent overall performance. This invention also provides a method for preparing the SAN / PCTG alloy material, which is simple to operate and can be industrialized on a large scale. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0028] <Preparation of Examples and Comparative Examples>

[0029] The raw materials used in the embodiments and comparative examples of this invention are all commercially available, but are not limited to these materials:

[0030] PCTG resin: grade PCTG TX1001, purchased from Eastman;

[0031] SAN Resin A: Based on the total mass of SAN resin, acrylonitrile content 35%, grade SAN 350HW, purchased from Kumho Petrochemical.

[0032] SAN Resin B: Based on the total mass of SAN resin, acrylonitrile content 25%, grade Tairisan NF2200, purchased from Formosa Plastics.

[0033] SAN Resin C: Based on the total mass of SAN resin, acrylonitrile content 18%, grade SAN 310TR, purchased from Kumho, South Korea;

[0034] Toughening agent: Acrylic rubber, acrylonitrile-butyl acrylate-styrene polymer, grade A600N, purchased from UMG Japan;

[0035] Compatibilizer: Styrene-N-phenylmaleimide-anhydrous maleic anhydride copolymer, brand name MS-NB, purchased from Denki Kagaku, Japan;

[0036] Antioxidant: Antioxidant 1010, commercially available;

[0037] Lubricant: Pentaerythritol stearate, commercially available;

[0038] PBT: Grade PBT GX121, purchased from Yizheng Chemical Fiber;

[0039] ABS high-adhesion powder: grade HR-181, purchased from Kumho, South Korea.

[0040] The preparation methods of the embodiments and comparative examples of the present invention are as follows:

[0041] S1: Weigh each component according to the proportions in Table 1 and Table 3, premix them, and obtain the premix;

[0042] S2: The premix from step S1 is fed into a twin-screw extruder for melt blending and extrusion granulation to obtain SAN / PCTG alloy material.

[0043] The twin-screw extruder has a screw length-to-diameter ratio of 40:1, a barrel temperature of 260℃, and a screw speed of 400 r / min.

[0044] <Test Standards>

[0045] The performance testing standards for the various embodiments and comparative examples of this invention are as follows:

[0046] Performance testing

[0047] 1. Mass swelling degree: The cylindrical test samples prepared in the above examples and comparative examples were recorded with an initial mass m0. They were then soaked in essential oil for 15 days. After soaking, the test samples were taken out, the essential oil on the surface of the test samples was wiped dry, and then weighed and recorded as mt. The mass swelling degree W (g / g) = mt / m0 was then calculated.

[0048] 2. Oil resistance test: The test sample is soaked in essential oil at 50℃ for 20 hours. Its tensile strength is tested according to JISK711 and its elongation at break is tested according to JISK7161.

[0049] Calculate its tensile strength retention rate and elongation at break retention rate. Tensile strength retention rate = tensile strength of oil resistance test / original tensile strength * 100%, elongation at break retention rate = elongation at break of oil resistance test / original elongation at break * 100%.

[0050] 3. Color Difference Test: The L, A, and B values ​​of each color plate of the test sample were measured using a spectrophotometer (X-Rite CI-7000A). The measurement observation aperture was 20mm. The X-Rite Color Eye 7000A was used, with D... 65 The light source reflection method was used to measure the hue (L, a, b) of the molded plates before and after irradiation. The initial test sample was used as the colorimetric reference standard, and the test sample soaked in essential oil for 15 days was used as the colorimetric sample. The colorimetric results were measured using the fluctuation range of ΔL / Δa / Δb / ΔE as the evaluation index. The total color difference value ΔE = (ΔL / Δa / Δb / ΔE) / Δb ... 2 +Δa 2 +Δb 2 ) 1 / 2 ΔL = L value of test sample - L value of standard sample, Δa = a value of test sample - a value of standard sample, Δb = b value of test sample - b value of standard sample.

[0051] Table 1. Formulations (parts by weight) for Examples 1-6

[0052]

[0053] Table 2. Performance test results of Examples 1-6

[0054]

[0055] Table 3. Comparative Examples 1-6 Formulations (parts by weight)

[0056] Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 PCTG resin 50 50 50 15 70 PBT 50 SAN resin A 20 20 14 55 SAN resin C 20 toughening agent 30 30 30 30 30 compatibilizer 0.2 0.2 0.2 0.2 0.2 0.2 ABS high-polymer powder 30 antioxidants 0.3 0.3 0.3 0.3 0.3 0.3 lubricant 0.2 0.2 0.2 0.2 0.2 0.2

[0057] Table 4. Performance test results of Comparative Examples 1-6

[0058] project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Comparative Example 6 Mass swelling degree 0.8 0.5 3.2 0.4 1.6 1.4 Tensile strength retention rate % 72 75 42 82 74 68 Color difference ΔE 1.6 10.2 7.5 2.6 3.5 6.9

[0059] As can be seen from the data of Examples and Comparative Example 1, the acrylonitrile content of the SAN resin selected in this invention is greater than or equal to 25%. Due to the micro-chemical reaction that occurs between the two phases during the blending process of SAN resin with high acrylonitrile content and PCTG resin, the interaction between the high acrylonitrile SAN resin and PCTG resin is strengthened. Therefore, when the same amount of SAN resin is used, although the color difference of the blend of SAN resin with low acrylonitrile content and PCTG resin can meet the requirements, the tensile retention rate is low.

[0060] As can be seen from the data in Examples and Comparative Example 2, after adding acrylate toughening agents, the polarity of polymer molecules decreases, the chain segments become more flexible, the fluidity increases, and the tensile strength retention rate, mass swelling degree, and color retention are all superior to the SAN / PCTG composite material without acrylate toughening agents.

[0061] As can be seen from the data in Examples and Comparative Examples 3-5, the raw material ratio of the present invention is moderate, and the SAN is modified with a specific amount of PCTG and toughening agent, which effectively enhances the oil resistance, solvent resistance and stability of the obtained SAN, resulting in excellent comprehensive performance.

[0062] In Comparative Example 6, no SAN resin was added to the formulation, and the mass swelling degree, tensile strength retention rate, and color difference of Comparative Example 6 all deteriorated.

[0063] As can be seen from the data of the examples, the SAN / PCTG alloy material provided by the present invention has a mass swelling degree ≤0.16, a tensile strength retention rate ≥93.4%, and a color difference ≤2.3. Therefore, the SAN / PCTG alloy material prepared by the present invention can be widely used in oil-resistant packaging materials, especially suitable for skin care product packaging, beauty oil packaging, essential oil packaging, etc., and has broad market prospects and market benefits.

[0064] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A SAN / PCTG alloy material, characterized in that, The components include the following weight parts: The PCTG resin is a copolymer of terephthalic acid, ethylene glycol and 1,4-cyclohexane dimethanol; The mass content of acrylonitrile in the SAN resin is greater than or equal to 25% based on the total mass of the SAN resin; The toughening agent is an acrylate-based toughening agent; The content of 1,4-cyclohexane dimethanol in the PCTG resin is > 50%.

2. The SAN / PCTG alloy material of claim 1, wherein The mass content of acrylonitrile in the SAN resin is 32-35% based on the total mass of the SAN resin.

3. The SAN / PCTG alloy material of claim 1, wherein The toughening agent is an acrylonitrile-butyl acrylate-styrene polymer.

4. The SAN / PCTG alloy material of claim 1, wherein The compatibilizer is a styrene-N-phenyl maleimide-anhydrous maleic anhydride copolymer.

5. The SAN / PCTG alloy material of claim 1, wherein It also includes 0.2-2 parts of an antioxidant.

6. A method of producing a SAN / PCTG alloy material according to any one of claims 1 to 5, characterized in that, The following steps are included: S1: After pre-mixing the components according to the ratio, a pre-mixture is obtained; S2: The pre-mixture of step S1 is put into an extruder for melt blending and extrusion granulation to obtain the SAN / PCTG alloy material.

7. Use of the SAN / PCTG alloy material according to any one of claims 1-5 in oil-resistant packaging materials.

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