阅读说明：本技术 一种长效抗变色防老剂的制备方法 (Preparation method of long-acting anti-tarnishing anti-aging agent ) 是由 张莉娜 唐英俊 方春平 于 2020-12-31 设计创作，主要内容包括：本发明公开了一种长效抗变色防老剂的制备方法,S1:将2-叔丁基—4-甲基苯酚、无水多聚甲醛、乳化剂、催化剂A和适量水加入到乳化机中,得到预乳化核体；S2:将马来酸酐、催化剂B和预乳化核体混合改性反应,形成具有活性表面的核层；S3：将步骤S2制备好的核层与苯乙烯、乙二醇、对苯二甲酸金属盐进行接枝共聚,形成具有核壳结构的改性防老剂,其中,对苯二甲酸金属盐是以碱减量废水中回收的对苯二甲酸为原料制备得到的。本发明不仅能改善橡塑制品的耐热老化性能,耐挥发、耐迁移、耐抽提,而且同时可适当减少增塑剂的添加量,改善加工性能和物理机械性能,综合的性价比高,满足用户要求。(The invention discloses a preparation method of a long-acting anti-tarnish anti-aging agent, S1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier, a catalyst A and a proper amount of water into an emulsifying machine to obtain a pre-emulsified core body; s2, mixing maleic anhydride, a catalyst B and a pre-emulsified core body for modification reaction to form a core layer with an active surface; s3: and (3) carrying out graft copolymerization on the nuclear layer prepared in the step (S2), styrene, ethylene glycol and terephthalic acid metal salt to form the modified anti-aging agent with the core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali weight reduction wastewater as a raw material. The invention can not only improve the thermal aging resistance, volatilization resistance, migration resistance and extraction resistance of the rubber and plastic product, but also properly reduce the addition of the plasticizer, improve the processing performance and the physical and mechanical properties, have high comprehensive cost performance and meet the requirements of users.)

1. A preparation method of a long-acting anti-tarnish anti-aging agent is characterized by comprising the following specific preparation processes:

s1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier, a catalyst A and a proper amount of water into an emulsifying machine, mixing and stirring at the rotation speed of 1000-;

s2, carrying out modification reaction on maleic anhydride, a catalyst B and a pre-emulsified core body at the temperature of 50-80 ℃ for 0.5-1.0h to form a core layer with an active surface;

s3: and (3) carrying out graft copolymerization on the nuclear layer prepared in the step (S2), styrene, ethylene glycol and terephthalic acid metal salt to form the modified anti-aging agent with the core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali weight reduction wastewater as a raw material.

2. The method for preparing the long-acting anti-tarnish anti-aging agent according to claim 1, wherein the molar ratio of the added amount of the 2-tert-butyl-4-methylphenol to the added amount of the anhydrous paraformaldehyde is 1: 0.5-0.65.

3. The preparation method of the long-acting anti-tarnish anti-aging agent according to claim 2, wherein the emulsifier is one of sodium dodecyl benzene sulfonate, sodium isopropyl naphthalene sulfonate, modified sodium lauryl sulfate or sodium laureth sulfate, and the amount of the emulsifier is 2-5% of the mass of 2-tert-butyl-4-methylphenol.

4. The method for preparing the long-acting anti-tarnish anti-aging agent according to claim 3, wherein the catalyst A is 49% of one of sulfuric acid, p-toluenesulfonic acid, benzenesulfonic acid or tetrafluoroboric acid, and the amount of the catalyst A is 0.2-0.5% of the mass of 2-tert-butyl-4-methylphenol.

5. The method for preparing the long-acting anti-tarnish anti-aging agent according to claim 4, wherein the addition amount of the maleic anhydride is 2 to 5 percent of the mass of the 2-tert-butyl-4-methylphenol.

6. The method for preparing a long-acting anti-tarnish anti-aging agent according to claim 5, wherein the catalyst B is acetic acid or oxalic acid, and the amount of the catalyst B is 0.1 to 0.3 percent of the mass of 2-tert-butyl-4-methylphenol.

7. The method for preparing the long-acting anti-tarnish anti-aging agent according to claim 6, wherein the metal terephthalate is any one or a mixture of two of calcium terephthalate, zinc terephthalate and magnesium terephthalate.

8. The method for preparing the long-acting anti-tarnish anti-aging agent according to claim 6, wherein the amount of styrene is 3% -12% of the mass of 2-tert-butyl-4-methylphenol, and the molar ratio of the addition amounts of styrene, ethylene glycol and terephthalic acid metal salt is 1:0.8-1.2: 0.8-2.4.

Technical Field

The invention relates to a preparation method of a long-acting anti-tarnishing anti-aging agent, belonging to the field of rubber additives.

Background

The nitrile-butadiene rubber (NBR) and polyvinyl chloride (PVC) thermoplastic elastomer is a main rubber used by rubber and plastic at present, has the main advantages of plasticity and ozone resistance of PVC, oil resistance and crosslinkability of NBR, certain flame retardant property and good physical and mechanical properties, can be widely used for fuel rubber tubes, wire and cable sheaths, printing rubber rolls and sealing products, is particularly widely applied to industries such as automobile sealing parts, parts and the like, and has good application prospect.

The NBR/PVC thermoplastic elastomer gradually loses the use value because the NBR contains double bonds and the material becomes hard and brittle under the action of thermal oxygen aging. In order to improve the thermal aging resistance of the thermoplastic elastomer, increase the use temperature and expand the range of use, an appropriate antioxidant is used. The common antioxidants RD and BLE belong to amine antioxidants, have a promoting effect on the decomposition of PVC and are generally not suitable for use; the para-substituent groups of the phenolic antioxidants 2246 and 264 on the benzene ring are CH3-, hydrogen ions are easy to remove, the stability is good, the antioxidant effect is good, and the phenolic antioxidants are suitable choices. Furthermore, when preparing heat-resistant and thermoplastic elastomers, the addition of a large amount of DOP, which is an organic small molecule and is prone to migration upon heating, also leads to a reduction in the heat aging resistance of the thermoplastic elastomer, so that the use of DOP for or with plasticizers of high relative molecular mass which are resistant to exudation should be minimized.

Disclosure of Invention

In order to solve the defects in the prior art, the invention provides a preparation method of a long-acting anti-tarnishing anti-aging agent, which not only can improve the heat-resistant aging performance, volatilization resistance, migration resistance and extraction resistance of a rubber and plastic product, but also can properly reduce the addition amount of a plasticizer, improve the processing performance and the physical and mechanical performance, has high comprehensive cost performance and meets the requirements of users.

The invention mainly adopts the technical scheme that:

a preparation method of a long-acting anti-tarnishing anti-aging agent comprises the following specific preparation processes:

s1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier, a catalyst A and a proper amount of water into an emulsifying machine, mixing and stirring at the rotation speed of 1000-;

s2, carrying out modification reaction on maleic anhydride, a catalyst B and a pre-emulsified core body at the temperature of 50-80 ℃ for 0.5-1.0h to form a core layer with an active surface;

s3: and (3) carrying out graft copolymerization on the nuclear layer prepared in the step (S2), styrene, ethylene glycol and terephthalic acid metal salt to form the modified anti-aging agent with the core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali weight reduction wastewater as a raw material.

Preferably, the 2-tert-butyl-4-methylphenol and the anhydrous paraformaldehyde are added in a molar ratio of 1: 0.5-0.65

Preferably, the emulsifier is one of sodium dodecyl benzene sulfonate, sodium isopropyl naphthalene sulfonate, modified sodium lauryl sulfate or sodium laureth sulfate, and the dosage of the emulsifier is 2-5% of the mass of 2-tert-butyl-4-methylphenol.

Preferably, the catalyst A is 49% of sulfuric acid, p-toluenesulfonic acid, benzenesulfonic acid or tetrafluoroboric acid, and the amount of the catalyst A is 0.2% -0.5% of the mass of the 2-tert-butyl-4-methylphenol.

Preferably, the addition amount of the maleic anhydride is 2-5% of the mass of the 2-tert-butyl-4-methylphenol.

Preferably, the catalyst B is acetic acid or oxalic acid, and the using amount of the catalyst B is 0.1-0.3% of the mass of the 2-tert-butyl-4-methylphenol.

Preferably, the terephthalic acid metal salt is any one or two mixtures of calcium terephthalate, zinc terephthalate and magnesium terephthalate.

Preferably, the amount of the styrene is 3-12% of the mass of the 2-tert-butyl-4-methylphenol, and the addition molar ratio of the styrene to the ethylene glycol to the metal terephthalate is as follows: 1:0.8-1.2:0.8-2.4.

Has the advantages that: the invention provides a preparation method of a long-acting anti-tarnish anti-aging agent, which has the following advantages:

1. on the basis of ensuring the anti-aging performance, the anti-aging coating is wrapped by calcium terephthalate, has a certain core-shell structure, and makes up the defect that the antioxidant 2246 turns yellow.

2. The calcium terephthalate salt has certain oil absorption and higher melting point, can ensure that the liquid plasticizer is not easy to separate out, resists volatilization, extraction and migration, relieves the migration problem, prolongs the effective life of the antioxidant in the rubber material, and has longer service life.

3. The invention adopts maleic anhydride modified core layer structure, improves the bonding strength of the core layer and the shell layer (styrene), and can improve the toughness of the rubber by adding the core layer and the shell layer into the rubber.

4. The terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali decrement wastewater as a raw material, so that the recycling of waste liquid is realized, and the resource utilization rate is improved.

Detailed Description

In order to make those skilled in the art better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application are clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Example 1

A preparation method of a long-acting anti-tarnishing anti-aging agent comprises the following specific preparation processes:

s1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier (sodium dodecyl benzene sulfonate, 2% of the mass of 2-tert-butyl-4-methylphenol), a catalyst A (49% of sulfuric acid, 0.2% of the mass of 2-tert-butyl-4-methylphenol) and a proper amount of water into an emulsifying machine, mixing and stirring at the rotating speed of 1000r/min, slowly heating to 80 ℃, and then preserving heat for 1 hour to obtain a pre-emulsified core body;

s2, carrying out modification reaction on maleic anhydride (2 mass percent of 2-tert-butyl-4-methylphenol), a catalyst B (0.1 mass percent of acetic acid and 2-tert-butyl-4-methylphenol) and a pre-emulsified core body at 50 ℃ for 0.5h to form a core layer with an active surface;

s3: and (3) carrying out graft copolymerization on the core layer prepared in the step S2, styrene (3% of the mass of 2-tert-butyl-4-methylphenol), ethylene glycol and terephthalic acid metal salt (calcium terephthalate) to form the modified anti-aging agent with a core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali-minimization wastewater as a raw material (the adding amount molar ratio of the styrene, the ethylene glycol and the terephthalic acid metal salt is 1:0.8: 0.8).

Example 2

A preparation method of a long-acting anti-tarnishing anti-aging agent comprises the following specific preparation processes:

s1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier (modified lauryl sodium sulfate, 3% of the mass of 2-tert-butyl-4-methylphenol), a catalyst A (p-toluenesulfonic acid, 0.3% of the mass of 2-tert-butyl-4-methylphenol) and a proper amount of water into an emulsifying machine, mixing and stirring at the rotating speed of 1200r/min, slowly heating to 90 ℃, and then preserving heat for 1.5 hours to obtain a pre-emulsified core body, wherein the adding amount molar ratio of the 2-tert-butyl-4-methylphenol to the anhydrous paraformaldehyde is 1: 0.6;

s2, carrying out modification reaction on maleic anhydride (4 percent of the mass of 2-tert-butyl-4-methylphenol), a catalyst B (0.2 percent of acetic acid, 0.2 percent of the mass of 2-tert-butyl-4-methylphenol) and a pre-emulsified core body at 70 ℃ for 1.0h to form a core layer with an active surface;

s3: and (2) carrying out graft copolymerization on the nuclear layer prepared in the step (S2) and styrene, ethylene glycol and terephthalic acid metal salt (calcium terephthalate) to form the modified anti-aging agent with a core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali reduction wastewater as a raw material, the dosage of the styrene is 6% of the mass of the 2-tert-butyl-4-methylphenol, and the addition amount molar ratio of the styrene to the ethylene glycol to the terephthalic acid metal salt is 1:1: 1.5.

Example 3

A preparation method of a long-acting anti-tarnishing anti-aging agent comprises the following specific preparation processes:

s1, adding 2-tert-butyl-4-methylphenol, anhydrous paraformaldehyde, an emulsifier (sodium dodecyl benzene sulfonate which is 5 percent of the mass of 2-tert-butyl-4-methylphenol), a catalyst A (49 percent of sulfuric acid which is 0.5 percent of the mass of 2-tert-butyl-4-methylphenol) and a proper amount of water into an emulsifying machine, mixing and stirring at the rotating speed of 1500r/min, slowly heating to 90 ℃, and then preserving heat for 2 hours to obtain a pre-emulsified core body, wherein the adding amount molar ratio of the 2-tert-butyl-4-methylphenol to the anhydrous paraformaldehyde is 1: 0.65;

s2, carrying out modification reaction on maleic anhydride (5 percent of the mass of 2-tert-butyl-4-methylphenol), a catalyst B (0.3 percent of the mass of oxalic acid and 2-tert-butyl-4-methylphenol) and a pre-emulsified core body at 80 ℃ for 1.0h to form a core layer with an active surface;

s3: and (2) carrying out graft copolymerization on the core layer prepared in the step (S2), styrene, ethylene glycol and terephthalic acid metal salt (zinc terephthalate) to form the modified anti-aging agent with a core-shell structure, wherein the terephthalic acid metal salt is prepared by taking terephthalic acid recovered from alkali reduction wastewater as a raw material, the dosage of the styrene is 12% of the mass of the 2-tert-butyl-4-methylphenol, and the addition amount molar ratio of the styrene, the ethylene glycol and the terephthalic acid metal salt is 1: 1.2: 2.4.

Examples 1, 2 and 3 and ordinary antioxidant 4020 were kneaded according to the kneading formulation shown in table 1 to obtain sample 1, sample 2, sample 3 and sample 4, respectively.

Table 1: the addition amount of each component in the mixing formula

The physical and mechanical properties of the rubber materials obtained by mixing the above samples 1, 2, 3 and 4 were measured before and after aging (100 ℃ C.. times.7 d) according to the national standard.

Weather aging resistance test method: taking the same standard sample, cutting the same standard sample into equal 3 pieces according to the length direction of the sample, wherein the length direction of the sample is vertical to the rolling and extruding directions, folding the test piece according to 360 degrees, fixing the same part of the test piece, then placing the test piece at the same position in the sunward direction, and observing the surface aging condition of the test piece after two months. The test results are shown in table 2.

TABLE 2 test results of mechanical properties and thermal aging resistance of each sample

The following conclusions can be drawn from the above experimental results:

1) the physical and mechanical properties of the rubber material added with the modified anti-aging agent are equivalent to those of the rubber material added with the common anti-aging agent 4020, and are slightly superior to those of the common anti-aging agent.

2) The rubber material added with the modified anti-aging agent still has no cracking phenomenon after being subjected to a weather aging resistance test for two months, and the rubber material added with the conventional anti-aging agent 4020 has slight whiteness and no cracking phenomenon after being subjected to a weather aging resistance test for two months, so that the modified anti-aging agent not only improves the weather aging cracking resistance of the rubber material, but also improves the anti-discoloration performance of the anti-aging agent.

The foregoing is merely a preferred embodiment of this invention and it will be appreciated by those skilled in the art that numerous modifications and adaptations can be made without departing from the principles of the invention.