Low odor antioxidant and method of making and using same

Abstract

The application relates to the technical field of antioxidants, in particular to IPC C08K5, and more particularly to a low-odor antioxidant as well as a preparation method and application thereof. The application provides a low-odor antioxidant, which is composed of, in mass percentage, 70-85% hindered phenolic antioxidant and 15-30% phosphite antioxidant. The low-odor antioxidant prepared in the application has a small addition amount, low VOC and atomization value, high high-temperature resistance, and is used for preparing high-rebound polyether.

Description

Technical Field

[0001] This invention relates to the field of antioxidant technology, particularly to IPC C08K5, and more specifically to a low-odor antioxidant, its preparation method, and its application. Background Technology

[0002] Polyurethane materials, due to their advantages such as good wear resistance, high strength, large load-bearing capacity, and good shock absorption, are widely used in household equipment to improve the comfort of various devices. Antioxidants, as an important component for improving the performance of polyurethane materials, also affect their final physicochemical properties. Currently, with increasing environmental awareness, manufacturers have raised their requirements for the use of antioxidants in polyurethane materials, especially for automotive cotton used in car interiors, which requires low VOC content and low fogging value.

[0003] Existing patent 201910566431.7 discloses a method for preparing a composite antioxidant that can better improve polymer processing and long-term yellowing due to aging. The composite antioxidant mainly consists of a primary antioxidant and an auxiliary antioxidant, a dispersant, an organic pigment, and an inorganic pigment. It effectively improves polymer processing and long-term yellowing due to aging, but its antioxidant effect still needs to be improved.

[0004] Existing patent CN201110043843.6 discloses a method for preparing an emulsion-type antioxidant. This antioxidant is mainly composed of phenolic antioxidants, liquid phosphite antioxidants, liquid thioether antioxidants, surfactants, and organic solvents. It has a good antioxidant effect, but it uses a lot of raw materials and has a high cost. Summary of the Invention

[0005] To address the aforementioned problems, the present invention provides a low-odor antioxidant, the components of which include hindered phenolic antioxidants and phosphite antioxidants.

[0006] Preferably, the hindered phenolic antioxidant has 30 to 60 carbon atoms; the phosphite antioxidant has 30 to 60 carbon atoms.

[0007] In this invention, hindered phenolic antioxidants and phosphite antioxidants with more than 30 carbon atoms are selected to reduce the VOC and atomization value of the antioxidants, thereby reducing the odor of sponge products and improving the user experience. The inventors discovered that commonly used antioxidants in existing sponge products typically have fewer than 30 carbon atoms, resulting in high VOC and atomization values ​​and consequently, strong odors. To reduce the odor of antioxidants and downstream sponge products, especially automotive sponges, the inventors selected antioxidants with more than 30 carbon atoms, which have fewer impurities and can reduce the VOC and atomization values ​​of the antioxidants themselves. However, most antioxidants with more than 30 carbon atoms are solids, making them difficult to integrate well with polyethers, thus affecting the antioxidant performance of sponge products.

[0008] Preferably, the hindered phenolic antioxidant includes any one of the following: a phenolic isomer of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecanoate, pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, and 4,4'-thiobis(6-tert-butyl-m-cresol); more preferably, it is a phenolic isomer of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecanoate.

[0009] Preferably, the phenolic isomer of the 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecanoate is a liquid.

[0010] Preferably, the phenolic isomer of the n-octadecyl alcohol ester of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate has a dynamic viscosity of 100-200 cp at 40°C; more preferably, it has a dynamic viscosity of 110 cp at 40°C.

[0011] Preferably, the phenolic isomer of the 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecanoate is derived from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd., and is designated as ST-1912.

[0012] Preferably, the ST-1912 preparation method includes the following: (1) 90-100g of 3,5-methyl ester, 1-3g of catalyst and 100-120g of isomeric 18-ol are added to a four-necked reaction flask (with a condenser for reflux sampling) to carry out transesterification reaction. The temperature is raised to 160-170 degrees and then refluxed under high negative pressure. After the reaction is carried out for 6-8 hours, a sample is taken for analysis, excess alcohol is distilled off, and the catalyst is filtered out after cooling to obtain ST-1912.

[0013] Preferably, the catalyst is monobutyltin oxide.

[0014] In this invention, by improving the synthesis method of ST-1912 and selecting monobutyltin oxide as a catalyst, the purity of ST-1912 is improved, the experimental steps are simplified, and the generation of by-products is reduced, thereby improving the performance of ST-1912 antioxidant.

[0015] Preferably, the phosphite antioxidant comprises a high molecular weight phosphite with a diphosphorus structure.

[0016] Preferably, the diphosphite high molecular weight phosphite includes any one of ST-606, ST-626, ST-636, and ST-9228; more preferably, it is ST-606.

[0017] Preferably, ST-606 is a liquid antioxidant.

[0018] Preferably, the dynamic viscosity of ST-606 is 30-50 cp at 40°C; more preferably, it is 45 cp at 40°C.

[0019] Preferably, the ST-606 is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0020] Preferably, the CAS number of the ST-606 is 69439-68-5.

[0021] In this invention, liquid antioxidants are used, with ST-1912 and ST-606 having dynamic viscosities of 100-200 cp at 40°C and 30-50 cp at 40°C respectively. The addition method is simple, improving the storage stability of the product while further increasing the initial oxidation temperature, thereby enhancing the antioxidant properties of the sponge product. The inventors discovered that adding solid antioxidants with more than 30 carbon atoms easily reduces the antioxidant properties of the sponge product. However, by selecting liquid antioxidants with 100-200 cp at 40°C and 30-50 cp at 40°C, the compatibility issue between the antioxidant and polyether is resolved. This improves the storage stability of the product while further increasing the initial oxidation temperature, thus enhancing the antioxidant properties of the sponge product. The inventors hypothesize that the molecules of the 100-200 cp, 40℃ and 30-50 cp, 40℃ liquid antioxidants in this invention can tightly bind with the macromolecules in the polyether, thereby improving compatibility with the polyether. Antioxidants with suitable dynamic viscosity can be uniformly dispersed in the polyether system, making them less prone to precipitation and stratification, thus improving the product's storage stability. Simultaneously, it increases the initial oxidation temperature and enhances the antioxidant properties of the sponge products. Furthermore, solid antioxidants produce a lot of dust, are difficult to pump and add, and can easily cause unnecessary feeding troubles for polyether manufacturers, increasing labor costs.

[0022] Preferably, the low-odor antioxidant comprises, by mass percentage, 70-85% hindered phenolic antioxidants and 15-30% phosphite antioxidants.

[0023] Preferably, the low-odor antioxidant comprises, by mass percentage, 70-85% ST-1912 and 15-30% ST-606.

[0024] In a preferred embodiment, the low-odor antioxidant comprises, by mass percentage, 70% ST-1912 and 30% ST-606.

[0025] In a preferred embodiment, the low-odor antioxidant comprises, by mass percentage, 80% ST-1912 and 20% ST-606.

[0026] In a preferred embodiment, the low-odor antioxidant comprises, by mass percentage, 85% ST-1912 and 15% ST-606.

[0027] In this invention, by controlling the mass percentage of hindered phenolic antioxidants to 70-85% and the mass percentage of phosphite antioxidants to 15-30% in the low-odor antioxidant, the UV resistance and core-burning resistance of the prepared sponge were improved. The inventors discovered that the antioxidant performance of the low-odor antioxidant is closely related to the mass ratio of hindered phenolic antioxidants to phosphite antioxidants. When 50wt% ST-1912 and 50wt% ST-606 were used, the phenolic yellow test results were improved, but the UV resistance and core-burning resistance decreased. In order to obtain a liquid antioxidant with good UV protection, anti-burning properties, and phenol yellow resistance, the inventors creatively adjusted the compounding ratio of ST-1912 and ST-606. They found that when the mass percentage of ST-1912 was 70-85% and the mass percentage of ST-606 was 15-30%, its UV protection and anti-burning properties were enhanced, and its effect was better than that of commonly used antioxidants 1076 and 1135. The effect of phenol yellow test was reduced, but it was still better than that of commonly used antioxidants 1076 and 1135.

[0028] In this invention, by adding 70-85 wt% ST-1912 and 15-30 wt% ST-606, the volatilization of pentabenzene-trialdehyde in polyether and downstream sponge products can be effectively suppressed. This invention hypothesizes that the addition of ST-1912 and ST-606 can prevent the aging of polyether and reduce the breakage of molecular chains in the polyether, thus preventing the escape of small molecule aldehydes and benzene compounds from polystyrene or downstream sponge products, thereby increasing odor. Especially in the preparation of automotive interior sponges, excessive odor can negatively impact car sales.

[0029] A second aspect of the present invention provides a method for preparing a low-odor antioxidant, comprising the following steps;

[0030] According to the mass percentage of the components of the low-odor antioxidant, the hindered phenolic antioxidant and the phosphite antioxidant are mixed and added to the reactor. The temperature is raised to 45-65°C, the stirrer is turned on, and the mixture is stirred for 25-35 minutes. A sample is taken for observation to see if it is clear and transparent. If it is transparent, it is sent for quality inspection and analysis to obtain the low-odor antioxidant.

[0031] Preferably, the temperature for heating is 50–60°C.

[0032] A third aspect of the present invention provides an application of a low-odor antioxidant in the preparation of high-resilience polyethers.

[0033] Preferably, the high-resilience polyether comprises sponge or foam.

[0034] Beneficial effects

[0035] 1. In this invention, by selecting hindered phenolic antioxidants and phosphite antioxidants with more than 30 carbon atoms, the VOC and atomization value of the antioxidants are reduced, thereby reducing the odor of sponge products and improving the user experience.

[0036] 2. In this invention, by using liquid antioxidants and controlling the dynamic viscosity to be 100-200 cp, ST-1912 at 40℃ and ST-1912 at 30-50 cp, ST-606 at 40℃, the addition method is simple. While improving the storage stability of the product, it further increases the initial oxidation temperature, thereby improving the antioxidant performance of the sponge product.

[0037] 3. In this invention, by controlling the mass percentage of hindered phenolic antioxidants and the mass percentage of phosphite antioxidants in the low-odor antioxidant to be 70-85% and 15-30% respectively, the UV resistance and core-burning resistance of the prepared sponge are improved.

[0038] 4. In this invention, by adding 70-85 wt% ST-1912 and 15-30 wt% ST-606, the volatilization of pentabenzene trialdehyde in polyether and downstream sponge products can be effectively suppressed.

[0039] 5. In this invention, by improving the synthesis method of ST-1912 and selecting monobutyltin oxide as a catalyst, the purity of ST-1912 is improved, the experimental steps are simplified, and the generation of by-products is reduced, thereby improving the performance of ST-1912 antioxidant.

[0040] 6. The low-odor antioxidant in this invention is added in small amounts, generally 1000-2500 ppm, and is priced affordably, making it acceptable to customers. At the same time, the product can significantly delay the color change time of polyether or sponge. Attached Figure Description

[0041] Figure 1 The image shows the UV test results of the sponges prepared using Example 1, antioxidant 1125, and antioxidant 1076; from left to right, they are antioxidant 1135, antioxidant 1076, and Example 1.

[0042] Figure 2 The image shows the results of a phenol yellow test on the sponges prepared using Example 1, antioxidant 1125, and antioxidant 1076; from left to right, they are antioxidant 1135, Example 1, and antioxidant 1076.

[0043] Figure 3 The image shows the results of the anti-core burning test after the sponges prepared by Example 1, antioxidant 1125, and antioxidant 1076 were tested; from left to right, they are antioxidant 1076, Example 1, and antioxidant 1135. Detailed Implementation

[0044] Example 1

[0045] This embodiment provides a low-odor antioxidant, the components of which include 80wt% ST-1912 and 20wt% ST-606.

[0046] The ST-1912 is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0047] The ST-1912 preparation method includes the following: (1) 90g of 3,5-methyl ester, 2g of catalyst and 100g of isomeric 18-ol are added to a four-necked reaction flask (with a condenser for reflux extraction) to carry out transesterification reaction. The temperature is raised to 165 degrees and then refluxed under high negative pressure. After 8 hours of reaction, a sample is taken for analysis, excess alcohol is distilled off, and the catalyst is filtered out after cooling to obtain ST-1912.

[0048] The catalyst is monobutyltin oxide.

[0049] The ST-606 mentioned above is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0050] The CAS number of the ST-606 is 69439-68-5.

[0051] The second aspect of this embodiment provides a method for preparing a low-odor antioxidant, including the following steps;

[0052] According to the mass percentage of the components of the low-odor antioxidant, the hindered phenolic antioxidant and the phosphite antioxidant are mixed and added to the reactor, heated to 55°C, and the stirrer is turned on. Stir for 30 minutes, take a sample and observe whether it is clear and transparent. If it is transparent, send it for quality inspection and analysis to obtain the low-odor antioxidant.

[0053] The third aspect of this embodiment provides an application of a low-odor antioxidant in the preparation of a high-resilience polyether. The high-resilience polyether is a sponge.

[0054] Example 2

[0055] This embodiment provides a low-odor antioxidant, the components of which include 70wt% ST-1912 and 30wt% ST-606.

[0056] The ST-1912 is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0057] The ST-606 mentioned above is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0058] The second aspect of this embodiment provides a method for preparing a low-odor antioxidant, including the following steps;

[0059] According to the mass percentage of the components of the low-odor antioxidant, the hindered phenolic antioxidant and the phosphite antioxidant are mixed and added to the reactor, heated to 55°C, and the stirrer is turned on. Stir for 30 minutes, take a sample and observe whether it is clear and transparent. If it is transparent, send it for quality inspection and analysis to obtain the low-odor antioxidant.

[0060] The third aspect of this embodiment provides an application of a low-odor antioxidant in the preparation of high-resilience polyether. The high-resilience polyether is a foam sponge.

[0061] Example 3

[0062] This embodiment provides a low-odor antioxidant, the components of which include 85wt% ST-1912 and 15wt% ST-606.

[0063] The ST-1912 is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0064] The ST-606 mentioned above is sourced from Shanghai Petrochemical Xinier Chemical Technology Co., Ltd.

[0065] The second aspect of this embodiment provides a method for preparing a low-odor antioxidant, including the following steps;

[0066] According to the mass percentage of the components of the low-odor antioxidant, the hindered phenolic antioxidant and the phosphite antioxidant are mixed and added to the reactor, heated to 55°C, and the stirrer is turned on. Stir for 30 minutes, take a sample and observe whether it is clear and transparent. If it is transparent, send it for quality inspection and analysis to obtain the low-odor antioxidant.

[0067] The third aspect of this embodiment provides an application of a low-odor antioxidant in the preparation of a high-resilience polyether. The high-resilience polyether is a sponge.

[0068] Comparative Example 1

[0069] The specific implementation method of Comparative Example 1 is the same as that of Example 1, except that the low-odor antioxidant is composed of 80 wt% antioxidant 1076 and 20 wt% ST-606.

[0070] The antioxidant 1076 mentioned above was purchased from the MIANOX brand.

[0071] Comparative Example 2

[0072] The specific implementation method of Comparative Example 2 is the same as that of Example 1, except that the low-odor antioxidant is composed of 50wt% ST-1912 and 50wt% ST-606.

[0073] Comparative Example 3

[0074] The specific implementation of Comparative Example 3 is the same as that of Example 1, except that the low-odor antioxidant is composed of 80wt% ST-1912 and 20wt% ST-626.

[0075] The ST-626 mentioned above is a solid antioxidant sourced from Shanghai Petrochemical Senior Chemical Technology Co., Ltd.

[0076] Performance testing

[0077] Foam sponge formulation; by weight, 100 parts polyether 5631D (purchased from Lanxing Dongda brand), 1 part silicone oil L580 (purchased from Jinan Guangxun Trading Co., Ltd.), 0.4 parts antioxidant, 4 parts water, 0.3 parts DABCO 33LV (purchased from Hengrui Polymer Materials (Shenzhen) Co., Ltd.), and 55 parts isocyanate (purchased from Shandong Shanhua Chemical Co., Ltd., Wanhua PM200, BASF 44V20, MDI50, 500, 5MDI)).

[0078] The antioxidants mentioned are the low-odor antioxidants prepared in Examples 1-3 and Comparative Examples 1-5, and antioxidant 1076 (purchased from MIANOX brand) and antioxidant 1135 (purchased from Baiyundu (Shanghai) Biotechnology Co., Ltd.);

[0079] 1. According to the above formula, antioxidants from Examples 1-3 and Comparative Examples 1-5 were added to make sponges. After curing for 24 hours, the sponges were cut and subjected to UV and phenol yellow energy tests. The results are shown in Table 1.

[0080] UV testing method: Cut the prepared foam sponge into strips of 100*30*10mm, wrap one end, place it in a UV oven, set the temperature to 50℃, and take it out after 12 hours. Use a PRECISION COLORIMETER NR10QC instrument to read the value and record the result in Table 1. Generally, read the ΔB value. The smaller the value, the better the effect.

[0081] Phenolic yellowing test method: According to the ISO 105-X18 standard (Textiles - Color fastness test - Part X18: Assessment of the phenolic yellowing potential of materials) published by the International Organization for Standardization (ISO), the phenolic yellowing of sponge products containing antioxidants 1076 and antioxidant 1135 prepared in Examples 1-3 and Comparative Examples 1-5 was tested, and the results are recorded in Table 1.

[0082] High-temperature core-burning resistance test method: 100 parts polyether 5631D, 2 parts silicone oil L580, 0.2 parts antioxidant, 9 parts water, 0.3 parts DABCO 33LV, and 105 parts isocyanate were used to make the product into a sponge. After curing for 4 hours, it was cut and observed. The results were recorded in Table 1.

[0083] Table 1

[0084] name Anti-burning core ΔB UV protection ΔB Phenol yellow ΔB Antioxidant 1076 9.77 15.88 11.04 Antioxidant 1135 11.11 14.65 11.69 Example 1 9.63 13.59 9.09 Example 2 9.12 13.26 8.82 Example 3 9.52 12.89 9.23 Comparative Example 1 11.32 13.68 11.24 Comparative Example 2 11.89 14.13 11.55 Comparative Example 3 10.95 14.87 10.77

[0085] 2. According to the above formula, antioxidants from Examples 1-3 and Comparative Examples 1-5 were added to make a sponge, and the 10L bag method was used for testing. The volatile organic compound (VOC) emissions from automotive interior materials were determined according to the sieve method of ISO 12219-2-2012. The atomization test was conducted according to ISO 6452-2007 International - Determination of fogging properties of automotive interior trim materials. The results are shown in Table 2.

[0086] Table 2

[0087] name TVOC ppm FOC ppm Antioxidant 1076 2.4 0.6 Example 1 2.5 0.6 Example 2 2.3 0.6 Example 3 2.3 0.5 Comparative Example 1 2.8 0.7 Comparative Example 2 3.0 0.9 Comparative Example 3 3.1 1.0

[0088] 3. Add 4000 ppm each of the low-odor antioxidants and antioxidants 1076 and 1135 prepared in Examples 1-3 and Comparative Examples 1-5 to polyether 5631D, stir well, and then place in a UV oven at 50°C for 4 hours. The color change of the polyether is shown in Table 3.

[0089] Table 3

[0090] name Color number Antioxidant 1076 15.7 Antioxidant 1135 25.3 Example 1 12.4 Example 2 13.0 Example 3 12.8 Comparative Example 1 14.3 Comparative Example 2 14.8 Comparative Example 3 15.1

[0091] 4. The low-odor antioxidants and antioxidants 1076 and 1135 prepared in Examples 1-3 and Comparative Examples 1-5 were added to blank polyether 5631D and stirred evenly. Then, samples were taken to test the initial oxidation temperature and the heating rate of 10℃ / min. The samples were placed in a pure oxygen environment with an oxygen purity of 99.99% or higher. When the exothermic curve rose significantly, the test was stopped. The results were obtained by instrumental analysis and are shown in Table 4.

[0092] Table 4

[0093]

Claims

1. A low odor antioxidant characterized in that, The low odor antioxidant comprises, in percentage by mass, 70-85% hindered phenolic antioxidant and 15-30% phosphite antioxidant; The hindered phenolic antioxidant is a phenolic isomer of 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid n-octadecyl ester, model ST-1912, from Shanghai Shike Xiniel Chemical Technology Co., Ltd. The phosphite antioxidant is ST-606.

2. A process for the preparation of a low odor antioxidant according to claim 1, characterized in that, The hindered phenolic antioxidant and the phosphite antioxidant are mixed according to the percentage by mass of the composition of the low odor antioxidant, and are added into a reaction kettle, and are heated to 45-65 DEG C, and a stirring machine is started, and is stirred for 25-35 minutes, and sampling observation is performed, and if transparent, it is sent to quality inspection analysis and testing to obtain the low odor antioxidant.

3. The method for preparing the low-odor antioxidant according to claim 2, characterized in that, The heating temperature is 50-60 DEG C.

4. Use of a low odor antioxidant according to claim 1, characterized in that, It is applied to preparation of high resilience polyether.

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