Pvc material anti-yellowing modifier, anti-yellowing pvc material under irradiation and preparation method thereof

Abstract

The application provides a PVC material anti-yellowing modifier, a PVC material resistant to radiation yellowing and a preparation method thereof, and relates to the technical field of high polymer materials.The PVC material anti-yellowing modifier is composed of a chlorine free radical capturing agent, a molecular chain repairing agent and an HCl absorbing agent.The PVC molecular structure is stabilized from the aspects of capturing chlorine free radicals, repairing the PVC molecular main chain, absorbing generated HCl and the like by the synergistic effect of the three free radical capturing agents, and the material yellowing factors are eliminated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of high molecular materials, and in particular to a PVC material yellowing resistance modifier suitable for electronic beam irradiation sterilization with less change in yellow index, a PVC material and a preparation method thereof. BACKGROUND

[0002] PVC (polyvinyl chloride) material has excellent transparency and chemical resistance, and its hardness can be changed with different amounts of plasticizer, and it is one of the plastic materials with large consumption in the field of disposable medical products.

[0003] The sterilization methods of medical materials usually include high-temperature steam sterilization, ethylene oxide sterilization and electronic beam irradiation sterilization, and the common sterilization method of PVC medical materials is ethylene oxide sterilization. On October 27, 2017, the International Agency for Research on Cancer of the World Health Organization listed ethylene oxide in the list of class 1 carcinogens, and the use of ethylene oxide sterilization method has the risk of polluting the environment, and the residual ethylene oxide on medical devices may also affect human health, and ethylene oxide is flammable and explosive, and safety accidents are easy to occur. Electronic beam irradiation sterilization has the characteristics of short time and no residue, and is widely used in the field of medical device disinfection abroad, and becomes the development direction of sterilization of disposable medical supplies.

[0004] The main reason why the current PVC medical products do not use electronic beam irradiation sterilization on a large scale is that the material has poor radiation resistance, and the color of the material changes greatly when it is irradiated by an electron beam, and even the material becomes dark brown. Therefore, it is very urgent to solve the problem of serious yellowing of PVC medical materials after electronic beam irradiation sterilization. SUMMARY

[0005] In view of the deficiencies of the prior art, the present application provides a PVC material yellowing resistance modifier, a radiation yellowing resistant PVC material and a preparation method thereof, and the PVC medical products produced by the method can be suitable for electronic beam irradiation sterilization.

[0006] One of the purposes of the present application is to provide a PVC material yellowing resistance modifier.

[0007] The second purpose of the present application is to provide a radiation yellowing resistant PVC material containing the PVC material yellowing resistance modifier.

[0008] The third purpose of the present application is to provide a preparation method of the radiation yellowing resistant PVC material.

[0009] In order to achieve the above-mentioned purposes of the present application, the following technical solutions are adopted:

[0010] In a first aspect, the present application provides a PVC material anti-yellowing modifier, which is composed of a chlorine radical scavenger, a molecular chain repair agent and an HCl absorbent, wherein the mass ratio of the chlorine radical scavenger, the molecular chain repair agent and the HCl absorbent is preferably (4.5-5.0):(0.8-1.0):(2.5-2.8).

[0011] In a second aspect, the present application provides a PVC material resistant to yellowing caused by irradiation, which comprises the following components in parts by mass: 100 parts of PVC resin, 1.2-1.5 parts of stabilizer, 45-55 parts of main plasticizer, 3-5 parts of auxiliary plasticizer, 0.4-0.6 parts of lubricant, 0.8-1.2 parts of antioxidant, and 1.2-1.5 parts of the above-mentioned anti-yellowing modifier.

[0012] The components are described in detail as follows:

[0013] The source of the PVC resin is not particularly limited and can be commercially available or prepared by a method known in the art.

[0014] Preferably, the PVC resin is prepared by a petroleum-ethylene process after chloroethylene monomer is prepared and then polymerized by a suspension method. Preferably, the average polymerization degree of the PVC resin is 1000-2500, preferably the average polymerization degree of the PVC resin is 1000, but is not limited thereto.

[0015] The amount of the PVC resin added is 100 parts.

[0016] The stabilizer can be a stabilizer known in the art.

[0017] Preferably, the stabilizer is an environmentally friendly odorless calcium-zinc stabilizer, such as AIMSTA-6802 of Shenzhen Zhihai Industry Co., Ltd., but is not limited thereto.

[0018] The amount of the stabilizer added is 1.2-1.5 parts, for example, can be 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, but is not limited thereto.

[0019] The main plasticizer can include, but is not limited to, diisooctyl cyclohexane-1,2-dicarboxylate (DEHCH), diisononyl cyclohexane-1,2-dicarboxylate (DINCH), dioctyl sebacate (DOS), etc., and is preferably diisononyl cyclohexane-1,2-dicarboxylate (DINCH) plasticizer.

[0020] The amount of the main plasticizer added is 45-55 parts, for example, can be 46 parts, 47 parts, 48 parts, 49 parts, 50 parts, 51 parts, 52 parts, 53 parts, 54 parts, but is not limited thereto.

[0021] The auxiliary plasticizer is epoxy soybean oil (ESBO) with auxiliary stabilizing effect, preferably, the epoxy value of the epoxy soybean oil (ESBO) is ≥6.2%, such as HM-01AD of Nantong Haoluoma Science and Technology Co., Ltd., but not limited thereto.

[0022] The addition amount of the auxiliary plasticizer is 3-5 parts, for example, can be 3 parts, 4 parts, 5 parts, but not limited thereto.

[0023] The lubricant can be a lubricating resin known in the art, including but not limited to low-density oxidized polyethylene wax lubricant, such as AC-629A of Honeywell, but not limited thereto.

[0024] The addition amount of the lubricant is 0.4-0.6 parts, for example, can be 0.4 parts, 0.5 parts, 0.6 parts, but not limited thereto.

[0025] The antioxidant can be an antioxidant known in the art, including but not limited to non-polluting hindered phenolic antioxidant and hindered amine antioxidant.

[0026] Preferably, the antioxidant is tri(ethylene glycol) bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate] (antioxidant 245), but not limited thereto.

[0027] The addition amount of the antioxidant is 0.8-1.2 parts, for example, can be 0.8 parts, 0.9 parts, 1 part, 1.1 parts, 1.2 parts, but not limited thereto.

[0028] The yellowing-resistant modifier is composed of a chlorine radical trapping agent, a molecular chain repair agent, and an HCl absorbent, and the mass ratio of the chlorine radical trapping agent, the molecular chain repair agent, and the HCl absorbent is (4.5-5.0):(0.8-1.0):(2.5-2.8).

[0029] The chlorine radical trapping agent can include but is not limited to bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, bis(2,4-dicumylphenyl) pentaerythritol-diphosphite, tris(1,2,2,6,6-pentamethylpiperidyl) phosphite, etc., preferably tris(1,2,2,6,6-pentamethylpiperidyl) phosphite.

[0030] The molecular chain repair agent can include but is not limited to N,N-diethylhydroxylamine (DEHA) or N-isopropylhydroxylamine (IPHA), etc., preferably N-isopropylhydroxylamine (IPHA).

[0031] The HCl absorbent can be a ternary hydrotalcite.

[0032] The amount of the yellowing-resistant modifier is 1.2-1.5 parts, for example, 1.2 parts, 1.3 parts, 1.4 parts, 1.5 parts, but is not limited thereto.

[0033] In a third aspect, the present application provides a preparation method of the above-mentioned yellowing-resistant PVC material, comprising the following steps: mixing PVC resin, stabilizer, main plasticizer, auxiliary plasticizer, lubricant, antioxidant, and yellowing-resistant modifier to obtain the yellowing-resistant PVC material.

[0034] Specifically, the preparation method comprises:

[0035] (1) Raw material mixing: adding PVC resin, stabilizer, lubricant, main plasticizer, and auxiliary plasticizer into a high-speed mixer to stir and heat, then adding antioxidant and yellowing-resistant modifier to continue stirring and heating, and placing the material into a low-speed mixer to stir until the material is cooled and discharged;

[0036] (2) Granulation: granulating the mixed material by using a double-screw granulator to obtain the yellowing-resistant PVC special material.

[0037] In some embodiments, in step (1), the high-speed mixer is stirred at a speed of 3000-4000 revolutions / min to heat to 100-110℃, and then continues to be stirred at a speed of 3000-4000 revolutions / min to heat to 125-135℃.

[0038] In some embodiments, in step (1), the material is placed into a low-speed mixer to stir at a speed of 300-400 revolutions / min until the material is cooled to 40℃ and then discharged.

[0039] In some embodiments, in step (2), the granulation temperature is 120℃-150℃, preferably 140℃-145℃.

[0040] Advantages:

[0041] The inventors of the present application found that after the PVC material is subjected to electron beam irradiation, the unstable allyl chloride atoms in the PVC molecular chain are easily removed to cause chain reaction, forming conjugated double bond structure in the molecular chain to cause the material to change color and yellow, and the PVC molecular main chain is also prone to breakage. In order to solve this problem, the present application creatively uses three kinds of free radical scavengers to cooperate from the aspects of capturing chlorine free radicals, repairing the PVC molecular main chain, and absorbing generated HCl to stabilize the PVC molecular structure, thereby eliminating the yellowing factors of the material.

[0042] The test results show that the change amount of the yellow index of the PVC material prepared by using the yellowing-resistant modifier composed of the three kinds of free radical scavengers before and after irradiation is about 5-6, which is at least one time lower than that of the ordinary PVC material without the yellowing-resistant modifier and the PVC material with only one kind of free radical scavenger; the thermal stability of the PVC material prepared by using the yellowing-resistant modifier composed of the three kinds of free radical scavengers can reach more than 60 min, while the thermal stability of the ordinary PVC material is only 50 min; in addition, the mechanical properties of the PVC material after adding the yellowing-resistant modifier are not affected.

[0043] The application has been described in detail above, but the above-mentioned embodiments are only illustrative in nature and are not intended to limit the application. In addition, the present application is not limited by any theory described in the foregoing prior art or summary of the application or in the following examples. DETAILED DESCRIPTION

[0044] The application will be further described below in conjunction with examples, and it should be noted that the following examples are provided only for illustrative purposes and do not constitute a limitation on the scope of the application.

[0045] Unless otherwise specified, the raw materials, reagents, methods and the like used in the examples are conventional raw materials, reagents and methods in the art.

[0046] The raw materials involved in the examples and comparative examples are as follows:

[0047] The PVC S-1000 resin is produced by Qilu Petrochemical Company.

[0048] The calcium-zinc stabilizer is AIMSTA-6802 of Shenzhen Zhihai Industry Co., Ltd.

[0049] The main plasticizer is diisononyl cyclohexane-1,2-dicarboxylate (DINCH) of BASF Company.

[0050] The auxiliary plasticizer is HM-01AD of Nantong Haoluoma Technology Co., Ltd.

[0051] The lubricant is AC-629A of Honeywell Company.

[0052] The antioxidant is antioxidant 245 of Tianjin Li'anlong New Material Co., Ltd.

[0053] Tris(1,2,2,6,6-pentamethylpiperidyl) phosphite is produced by Shijiazhuang Hongsen Chemical Co., Ltd.

[0054] N-isopropylhydroxylamine is produced by Guangzhou Yuanda New Material Co., Ltd.

[0055] The ternary hydrotalcite is produced by Xianghe Technology Co., Ltd.

[0056] Examples and Comparative Examples

[0057] The PVC material formulations (mass parts) of Examples 1-10 and Comparative Examples 1-4 are shown in Tables 1-3.

[0058] Table 1

[0059] Component Example 1 Example 2 Example 3 Example 4 Example 5 PVC S-1000 100 100 100 100 100 Calcium-zinc stabilizer 1.5 1.5 1.2 1.3 1.4 Primary plasticizer 50 55 45 50 50 Secondary plasticizer 5 3 4 4 4 Lubricant 0.5 0.5 0.5 0.6 0.4 Antioxidant 1.2 1.0 1.1 1.2 0.8 Anti-yellowing modifier 1.5 1.2 1.4 1.3 1.3

[0060] In Examples 1-5, the complex formulation of the yellowing resistance modifier is tris(1,2,2,6,6-pentamethylpiperidyl) phosphite, N-isopropylhydroxylamine and ternary hydrotalcite, and the mass ratio of tris(1,2,2,6,6-pentamethylpiperidyl) phosphite, N-isopropylhydroxylamine and ternary hydrotalcite is 5.0:0.8:2.5.

[0061] Table 2

[0062]

[0063]

[0064] In Examples 6-10, the complex formulation of the yellowing resistance modifier is tris(1,2,2,6,6-pentamethylpiperidyl) phosphite, N-isopropylhydroxylamine and ternary hydrotalcite, and the mass ratio of tris(1,2,2,6,6-pentamethylpiperidyl) phosphite, N-isopropylhydroxylamine and ternary hydrotalcite is 4.5:1.0:2.8.

[0065] Table 3

[0066]

[0067] Preparation of Examples and Comparative Example Samples and Performance Testing Methods:

[0068] (1) Raw material mixing: PVC resin, stabilizer, lubricant, main plasticizer and auxiliary plasticizer are added into a high-speed mixer and mixed, and then stirred at a speed of 3000 rpm until the temperature is raised to 100°C, and then antioxidant and yellowing resistance modifier are added, and the stirring is continued at a speed of 3000 rpm until the temperature is raised to 125°C; the material is placed into a low-speed mixer and stirred at a speed of 300 rpm, and then discharged when the material temperature cools to 40°C.

[0069] (2) Special material granulation process: the mixed material is granulated by a double screw granulator at a temperature of 140-145°C.

[0070] (3) The granules are plasticized on a double roll mill at a temperature of 165°C for 3 min, and then molded into a 0.5 mm thick sample sheet by a press, and then into a dumbbell-shaped sample for performance testing.

[0071] Test standards: A, tensile strength and elongation at break performance according to GB / T 1040.2-2022 "Determination of tensile properties of plastics - Part 2: test conditions for moulded and extruded plastics". B, yellow index according to HB / T 3802-2006 "Plastics - Determination of yellowness index". C, the electron beam irradiation dose of the sample piece is 25 kGy. D, thermal stability time according to GB / T 2917.1-2002 "Determination of release of hydrogen chloride and any other acidic products at elevated temperature from blends and articles based on vinyl chloride homopolymers and copolymers - Congo red method".

[0072] The performance was detected, and the results are shown in Tables 4-6:

[0073] Table 4

[0074]

[0075] Table 5

[0076]

[0077] Table 6

[0078]

[0079]

[0080] Comparative example 1 does not add a free radical scavenger, and comparative examples 2, 3 and 4 use a free radical scavenger alone. From the yellow index of the sample before and after irradiation, the comparative example sample changes greatly.

[0081] The above examples are only used to illustrate the technical solutions of the present application, and not to limit it. Although the present application has been described in detail with reference to the foregoing examples, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing examples can be modified or some or all of the technical features can be replaced equivalently without departing from the spirit and essence defined by the claims of the present application.

Claims

1. A radiation yellowing resistant PVC material, characterized in that, The components include, by mass fraction, 100 parts of PVC resin, 1.2-1.5 parts of stabilizer, 45-55 parts of main plasticizer, 3-5 parts of auxiliary plasticizer, 0.4-0.6 parts of lubricant, 0.8-1.2 parts of antioxidant, and 1.2-1.5 parts of yellowing-resistant modifier; The yellowing-resistant modifier is a combination of chlorine radical scavenger, molecular chain repair agent, and HCl absorbent; The chlorine radical scavenger is one or more selected from bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphate, bis(2,4-dicumylphenyl) pentaerythritol-diphosphite, and tris(1,2,2,6,6-pentamethylpiperidyl) phosphite; The molecular chain repair agent is one or both of N,N-diethylhydroxylamine and N-isopropylhydroxylamine; The HCl absorbent is a ternary hydrotalcite; The mass ratio of the chlorine radical scavenger, the molecular chain repair agent, and the HCl absorbent is (4.5-5.0):(0.8-1.0):(2.5-2.8).

2. The radiation-hydrolysis resistant PVC material according to claim 1, characterized in that, The chlorine radical scavenger is tris(1,2,2,6,6-pentamethylpiperidyl) phosphite; The molecular chain repair agent is N-isopropylhydroxylamine.

3. The radiation-hydrolysis resistant PVC material of claim 1, wherein, The PVC resin is prepared by a petroleum ethylene process to obtain vinyl chloride monomer and then by a suspension polymerization process; The average polymerization degree of the PVC resin is 1000-2500.

4. The radiation-hydrolysis resistant PVC material of claim 1, wherein, The stabilizer is a calcium-zinc stabilizer.

5. The radiation-hydrolysis resistant PVC material of claim 1, wherein, The main plasticizer is one or more selected from diisooctyl cyclohexane-1,2-dicarboxylate, diisononyl cyclohexane-1,2-dicarboxylate, and dioctyl sebacate.

6. The radiation-hydrolysis resistant PVC material of claim 1, wherein, The auxiliary plasticizer is epoxy soybean oil; The epoxy value of the epoxy soybean oil is ≥6.2%.

7. The radiation-hydrolysis-resistant PVC material according to claim 1, characterized in that, The lubricant is low-density oxidized polyethylene wax.

8. The radiation-hydrolysis resistant PVC material of claim 1, wherein, The antioxidant is a hindered phenolic antioxidant.

9. The radiation-hydrolysis-resistant PVC material according to claim 8, characterized in that, The antioxidant is triethylene glycol bis[β-(3-tert-butyl-4-hydroxy-5-methylphenyl) propionate].

10. A process for the production of a radiation-yellowing resistant PVC material according to any one of claims 1 to 9, characterized in that The method comprises the following steps: (1) Raw material mixing: the PVC resin, the stabilizer, the lubricant, the main plasticizer, and the auxiliary plasticizer are added into a high-speed mixer and stirred to be heated, then the antioxidant and the yellowing-resistant modifier are added and stirred to be heated, and the material is placed into a low-speed mixer and stirred to be cooled before being discharged; (2) Granulation: the mixed material is granulated by a double-screw granulator to obtain the yellowing-resistant PVC special material; In step (1), the high-speed mixer is stirred at a speed of 3000-4000 rpm to be heated to 100-110°C, and then stirred at a speed of 3000-4000 rpm to be heated to 125-135°C; In step (1), the material is placed into the low-speed mixer and stirred at a speed of 300-400 rpm until the material is cooled to 40°C before being discharged; In step (2), the granulation temperature is 120-150°C.

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