CN115894391A - Hindered phenol antioxidant and preparation method thereof, ABS emulsion type antioxidant composition and ABS resin prepared from ABS emulsion type antioxidant composition - Google Patents

Abstract

The invention provides a hindered phenol antioxidant and a preparation method thereof, an ABS emulsion type antioxidant composition and ABS resin prepared from the ABS emulsion type antioxidant composition. The invention connects hindered phenol antioxidant containing unsaturated double bond to triazine amino stilbene fluorescent whitening agent through substitution reaction to prepare a novel hindered phenol antioxidant, and then compounds the hindered phenol antioxidant and alpha-lipoic acid, and disperses the emulsifier and the thickener in deionized water to obtain the novel emulsion antioxidant composition. The ABS rubber powder prepared by the ABS rubber powder has less residue, the b value of the ABS resin is less than 10, and the impact resistance, the tensile strength and the bending strength of the ABS resin are also effectively improved.

Description

Hindered phenol antioxidant and preparation method thereof, ABS emulsion type antioxidant composition and ABS resin prepared from ABS emulsion type antioxidant composition

Technical Field

The invention belongs to the field of macromolecules, and particularly relates to a hindered phenol antioxidant and a preparation method thereof, an ABS emulsion type antioxidant composition and an ABS resin prepared from the ABS emulsion type antioxidant composition.

Background

The ABS resin is an engineering plastic with excellent performance, is formed by graft copolymerization of three monomers of acrylonitrile, butadiene and styrene, has a core-shell structure, takes a polybutadiene rubber phase as a core, can play a toughening effect and provide impact resistance for the resin, and takes a styrene-acrylonitrile resin (SAN) as a shell to enhance the compatibility of a dispersed phase and a continuous phase. The ABS resin is prepared by polymerizing butadiene emulsion, grafting acrylonitrile and styrene to polybutadiene emulsion, demulsifying, filtering, dehydrating, drying and the like, and finally blending and extruding ABS rubber powder and SAN resin.

The polybutadiene in the ABS resin has double bonds which are easily broken under the influence of external conditions such as shearing, heat and impurities, so that the ABS resin is aged and degraded, and the mechanical property of the ABS is reduced and the phenomena such as color change and the like are finally caused.

The polymer needs to be inhibited from being degraded by thermal oxidation through adding a proper antioxidant, and since the thermal oxidation degradation of the polymer can generate free radicals, hydroperoxides, impurities and the like, the corresponding antioxidant needs to be introduced to inhibit the processes, and correspondingly, a variety of antioxidants exist, and each antioxidant has a unique structure. There are a radical scavenger, H.donor, complexing agent, hydroperoxide decomposer, and the like. Then, the antioxidant is required to have unique properties, such as strong stability of the antioxidant radical, hydrogen atoms more reactive than the high molecular chain hydrogen atoms, and a boiling point high enough to avoid volatilization or decomposition during high temperature processing. Usually, the emulsion antioxidant is added before the ABS emulsion is discharged, and the powder antioxidant is added during blending, so that the excellent ageing resistance of the ABS resin is ensured through the two ways.

The aging phenomenon of the ABS resin is delayed by adding a complex compound antioxidant in the ABS emulsion polymerization process. Hindered phenols are usually selected as main antioxidants, and sulfur-containing synergists are selected as auxiliary antioxidants to prepare high-efficiency emulsion type compound antioxidants, and the high-efficiency emulsion type compound antioxidants are added into ABS emulsion to protect ABS grafting powder. Phenolic antioxidants are the most widely used antioxidants at present, can effectively and long-term protect plastic products under high-temperature conditions, and can also keep the stability of molten polymers in the processing process. The long-chain aliphatic sulfur-containing ester is a hydroperoxide decomposer which can only act after the generation of hydroperoxide, so that the hydroperoxide can not generate active free radicals, and the initiation process of autocatalysis is delayed, therefore, the long-chain aliphatic sulfur-containing ester is not used independently and is used together with a phenolic antioxidant, and the Montmong (antioxidant emulsion for ABS, the preparation and the agglomeration process research, master paper of the university of double denier, 2013) adopts an emulsion type antioxidant which comprises hindered phenolic antioxidant Wingstay L (butylated reaction product of p-cresol and dicyclopentadiene) and thiodipropionate to prepare ABS rubber powder, wherein b is about 19, and b of the ABS resin is 13.93 finally. The conventional emulsion antioxidant can reduce b x value of ABS resin to 12, the whiteness is difficult to be reduced to lower, and the residue existing in ABS can bring unpleasant odor to the resin.

Disclosure of Invention

In view of the above problems in the prior art, an object of the present invention is to provide a hindered phenol antioxidant and a preparation method thereof, wherein a hindered phenol antioxidant containing an unsaturated double bond is linked to a triazine amino stilbene fluorescent whitening agent through a substitution reaction to obtain a novel hindered phenol antioxidant.

The invention also aims to provide an ABS emulsion type antioxidant composition, which is prepared by dispersing the novel hindered phenol antioxidant and alpha-lipoic acid by using an emulsifier. The white brightening agent can complement yellow light of a resin matrix, achieve a whitening effect, and reduce the b value of the ABS resin. And because the antioxidant composition contains unsaturated double bonds, the antioxidant composition can react with residual monomers, so that the odor of ABS rubber powder is reduced, the whiteness of the ABS resin is greatly improved, and the mechanical properties such as impact resistance and the like of the ABS resin are ensured.

The invention also aims to provide an ABS resin prepared from the ABS emulsion type antioxidant composition, which has the advantages of less residue, reduced b x value of the ABS resin to be below 10 and the like, and simultaneously has improved impact resistance, tensile strength and bending strength.

In order to realize the purpose of the invention, the technical scheme adopted by the invention is as follows:

the invention provides a hindered phenol antioxidant which has a structure shown as a formula (1):

in the formula, R ₁ is-C _n H _2n -，n＝1-4。

The invention provides a preparation method of the hindered phenol antioxidant, which is synthesized by substituting a hindered phenol antioxidant without saturated double bonds and a triazine amino stilbene type fluorescent brightener, and comprises the following steps:

1) Carrying out dehydrogenation reaction on 2, 6-tert-butyl-p-cresol and alkane under the action of a catalyst to generate an intermediate A;

2) Heating the intermediate A prepared in the step 1) and halogen under the illumination condition for halogenation, and then adding an aqueous alkali solution for hydrolysis reaction to generate an intermediate B;

3) Cyanuric chloride and 4,4 '-diaminostilbene-2, 2' -disulfonic acid sodium salt are subjected to condensation reaction to generate an intermediate C;

4) And carrying out substitution reaction on the intermediate C prepared in the step 3) and the intermediate B prepared in the step 2) to prepare the hindered phenol antioxidant shown in the formula (1).

In step 1) of the invention, the alkane structure is CH ₃ -R ₂ Wherein R is ₂ is-C _n H _2n+1 ，n＝1-4；

The catalyst is selected from one or more of platinum, rhodium and palladium catalysts, and preferably one or more of platinum, rhodium and palladium chlorides.

In step 1), the molar ratio of the 2, 6-tert-butyl-p-cresol to the alkane is 1:0.5-1:2, preferably 1:1.2-1:1.5;

the amount of the catalyst is 0.5-3%, preferably 1-2% of the mass of 2, 6-tert-butyl-p-cresol.

In the step 1), the dehydrogenation reaction is carried out at the temperature of 170-190 ℃, preferably 170-180 ℃; the time is 4-10h, preferably 5-7h.

In the step 1), the intermediate A has a structure shown in a formula (2):

in the formula, R ₂ is-C _n H _2n+1 ，n＝1-4。

In step 2) of the present invention, the halogen is selected from chlorine, bromine and iodine, preferably chlorine;

the molar ratio of the intermediate A to the halogen is 1-3:1, preferably 1.5-2:1.

in the step 2), the halogenation reaction is carried out under the illumination condition, the illumination intensity is 100-1000lx, and the wavelength is 400-800nm;

the halogenation reaction is carried out at the temperature of 70-100 ℃, preferably at the temperature of 90-100 ℃; the time is 5-10h, preferably 6-8h.

In step 2) of the present invention, the aqueous alkali solution is selected from one or more of aqueous metal hydroxide solutions, preferably at least one of aqueous sodium hydroxide solution and aqueous potassium hydroxide solution;

preferably, the aqueous alkali solution has a concentration of 5 to 10wt%, preferably 5 to 7wt%;

the molar ratio of the intermediate A to water in the aqueous alkali solution is 1:20-100, preferably 1:30-60.

In the step 2), the hydrolysis reaction is carried out at the temperature of 20-50 ℃, preferably 25-40 ℃; the time is 2-6h, preferably 3-5h.

In the step 2), the intermediate B has a structure shown in a formula (3):

in the formula, R ₁ is-C _n H _2n -，n＝1-4。

In step 3) of the invention, the molar ratio of cyanuric chloride to sodium salt of 4,4 '-diaminostilbene-2, 2' -disulfonic acid is 5-2:1, preferably 2-1:1 for example 2:1;

among them, 4 '-diaminostilbene-2, 2' -disulfonic acid sodium salt (abbreviated as DSD acid sodium salt) is a product disclosed in the prior art, and can be obtained commercially or by self-making, and the source of the invention is not particularly limited, for example, in some specific examples, the invention can prepare DSD acid sodium salt by the method disclosed in CN 101066942A.

In step 3) of the present invention, the condensation reaction is carried out at a temperature of-3 to 3 ℃, preferably 0 to 2 ℃, for example, 0 ℃; for a period of 1 to 6 hours, preferably 2 to 4 hours such as 3 hours;

and controlling the pH value of a reaction system to be 3-4 in the condensation reaction process, and preferably regulating the pH value by adopting sodium carbonate.

In the step 3), the intermediate C has a structure shown in a formula (4):

in the step 4), the molar ratio of the intermediate C to the intermediate B is 1:1-6 preferably 1:3-5.

In the step 4), the temperature of the substitution reaction is 50-90 ℃, preferably 65-90 ℃; the time is 4 to 9 hours, preferably 6 to 8 hours;

in the process of the substitution reaction, the pH value of the reaction system is controlled to be 3-7, and is preferably regulated and controlled by sodium carbonate.

The invention also provides an ABS emulsion type antioxidant composition, which comprises the hindered phenol antioxidant shown in the formula (1) and alpha-lipoic acid;

the mass ratio of the hindered phenol antioxidant shown in the formula (1) to the alpha-lipoic acid is (5-1): 1, preferably 4-2.

In some specific examples, the ABS emulsion antioxidant composition further comprises other auxiliary agents, and the auxiliary agents are selected from one or more of an emulsifier, a thickening agent, a defoaming agent, water and the like;

the emulsifier is an anionic emulsifier, preferably one or more of potassium oleate, disproportionated potassium rosinate and sodium dodecyl sulfate;

the thickener is polyvinyl alcohol, and the preferred alcoholysis degree is 54-57 mol%;

the defoaming agent is a phosphate defoaming agent, and tributyl phosphate and octyl phosphate are preferably selected.

Preferably, in some specific examples, the ABS emulsion antioxidant composition comprises, by weight:

10-40 parts of hindered phenol antioxidant shown in formula (1), preferably 30-40 parts;

2-20 parts of alpha-lipoic acid, preferably 10-15 parts;

1-12 parts of emulsifier, preferably 5-10 parts;

0-2 parts of thickening agent, preferably 0-1 part;

0-0.3 part of defoaming agent, preferably 0-0.2 part;

80-120 parts of water, preferably 80-100 parts of water.

The ABS emulsion type antioxidant composition is prepared by the following method, and the preparation method comprises the following steps:

s1: mixing part of water and emulsifier uniformly under stirring;

s2: adding hindered phenol antioxidant shown in formula (1) and alpha-lipoic acid into the S1 system, and stirring to obtain emulsion;

s3: adding a residual water diluting system into the S2 emulsion;

s4: and adding a thickening agent and a defoaming agent into the S3 system, and uniformly mixing to obtain the ABS emulsion type antioxidant composition.

In the invention, in the step S1, the mixture is stirred for 2-8min at normal temperature and pressure.

In the invention, the emulsification process of the step S2 is carried out at the temperature of 60-90 ℃ and the stirring is carried out for 5-15min under normal pressure.

In the invention, the dilution process of the step S3 is carried out at the temperature of 60-90 ℃ and the stirring is carried out for 3-10min under normal pressure.

In the invention, the mixing process of the step S4 is carried out at the temperature of 60-90 ℃ and the stirring is carried out for 5-10min under normal pressure.

In the invention, the water is added twice in the preparation process, 10-30 parts of water is added in the step S1, and the rest of water is added in the step S3.

The invention also provides ABS resin, which is prepared from the ABS emulsion type antioxidant composition;

preferably, the ABS emulsion antioxidant composition is added in an amount of 3-12wt%, preferably 5-10wt%, based on the total mass of the ABS resin.

The preparation process of the ABS resin is not the research focus of the invention, the ABS resin can be prepared by adopting a method known in the field, the addition of the antioxidant in the preparation process of the ABS resin is the conventional operation in the field, and the invention has no special requirement.

In the invention, the ABS resin is prepared by mixing an ABS emulsion type antioxidant composition with ABS graft latex, then coagulating, dehydrating and drying the ABS graft latex added with the ABS emulsion type antioxidant composition to obtain ABS rubber powder, and then blending and granulating the ABS rubber powder with SAN resin, wherein the above process is a conventional technology in the field. For example, in some specific examples of the present invention, polybutadiene latex is prepared by butadiene polymerization, and then ABS graft latex is obtained by graft copolymerization of the polybutadiene latex with acrylonitrile and styrene monomers, and then ABS rubber powder is obtained by operations such as coagulation, filtration, dehydration and drying, and the specific operations can refer to pages 36-58 of "ABS resin production practice and application" written by suyanhui, etc., and the specific operations of ABS rubber powder and SAN resin by blending, extrusion and granulation can refer to the contents disclosed on pages 68-74 of this book, and specific raw material ratios and operating conditions, and those skilled in the art can perform combination screening according to actual needs, and the present invention is not described in detail.

Compared with the prior art, the technical scheme of the invention has the beneficial effects that:

the hindered phenol antioxidant with a novel structure is prepared by connecting the hindered phenol antioxidant containing unsaturated double bonds to the triazine amino stilbene type fluorescent whitening agent through a substitution reaction, and the molecular structure of the fluorescent whitening agent can excite blue light and purple light and is complementary with yellow light of a resin matrix, so that the whitening effect is achieved. The hindered phenol antioxidant prepared by the invention also has larger steric hindrance, can effectively protect the stability of phenolic hydroxyl, has wider use temperature range, simultaneously enables the hydrophobicity of the antioxidant to be stronger, and prevents the antioxidant from losing in the washing process of rubber powder.

The novel hindered phenol antioxidant and the alpha-lipoic acid are compounded to prepare the ABS emulsion antioxidant composition, the emulsion antioxidant can be uniformly dispersed in ABS emulsion, and the emulsion is uniformly dispersed in rubber powder after emulsion breaking, so that the antioxidant effect is fully exerted. The unsaturated double bond of the hindered phenol antioxidant can be mixed with unreacted monomers such as butadiene, styrene, acrylonitrile and the like, so that the residual monomers are eliminated, and the taste of the ABS rubber powder is improved. The alpha-lipoic acid is compounded with the alpha-lipoic acid, and simultaneously, the thermal oxidation aging of the ABS is synergistically inhibited, the phenomena that the ABS resin is degraded in the melting processing process and becomes yellow and dark are avoided, the b value of the ABS resin is finally reduced, the whiteness is increased, and the mechanical properties of the ABS resin, such as impact resistance, tensile strength, bending strength and the like, are ensured.

Drawings

FIG. 1 is a nuclear magnetic hydrogen spectrum of intermediate A prepared in example 1;

FIG. 2 is a nuclear magnetic hydrogen spectrum of intermediate B prepared in example 1;

FIG. 3 is a nuclear magnetic hydrogen spectrum of intermediate C prepared in example 1;

FIG. 4 is a nuclear magnetic hydrogen spectrum of the hindered phenol antioxidant prepared in example 1.

Detailed Description

The present invention is further illustrated by the following examples, which should be construed as limiting the scope of the invention.

The following examples and comparative examples of the present invention gave the following information on the source of the main raw materials, and the others were obtained from commercial sources unless otherwise specified;

polyvinyl alcohol 1788, available from Xinte Tima, UK;

tributyl phosphate defoamer, T100707, purchased from alatin; .

Cyanuric chloride, C118499, available from alatin;

alpha-lipoic acid, a28983, purchased from enokay;

sodium carbonate, S113834, purchased from alatin;

DSD acid sodium salt, purity 95%, purchased from Beijing Bailingwei science and technology Limited;

2, 6-tert-butyl-p-cresol, A93655, available from Ito;

alkane and chlorine are provided by the Wanhua chemical industry park of the company;

sodium hydroxide, I13475, available from enokay;

potassium oleate, BM-400, purchased from Ito reagent;

palladium chloride, I05713, was purchased from Ino reagent.

The following test methods were used in the examples of the invention:

yellow index: standard ASTM E313-15E1, using the United states Hunterlab VIS instrument.

Mechanical properties: tensile standard ASTM D638, using INSTRON 5966, usa; bending standard ASTM D790 using mitsunm 4104X; notched izod impact standard ASTM D256, 23 ℃, using the italian CEAST 9050.

The test method of the acrylonitrile, styrene and butadiene residual monomers in the ABS rubber powder comprises the following steps: a sample of 0.2g was taken in a 20ml headspace bottle to the nearest 0.1mg, 1.8g DMF was added and the sample was analysed by PE Turbomatrix 40 headspace sampler and Shimadzu GC 2010 gas chromatograph to test residual monomer content.

Example 1

Preparing hindered phenol antioxidant, comprising the following steps:

1) Feeding 2, 6-tert-butyl-p-cresol and ethane according to a molar ratio of 1 ₂ Methyl, i.e., 2, 6-t-butyl-p-allylphenol), the structure of which was analyzed by nuclear magnetic hydrogen spectroscopy, and the spectrum was shown in fig. 1.

2) Irradiating the intermediate A generated in the step 1) at 90 ℃ under the light source with the illumination intensity of 500lx and the wavelength of 600nm, wherein the molar ratio of the intermediate A to the intermediate A is 2:1 introducing chlorine gas into the reactor, wherein the chlorine gas is introduced into the reactor,halogenation is carried out for 6h at 90 ℃, then 5wt% sodium hydroxide aqueous solution is added (the molar ratio of water to intermediate A is 50 ₁ Methyl, i.e., 2, 6-t-butyl p-allylphenol), the structure of which is analyzed by nuclear magnetic hydrogen spectroscopy, and the spectrum is shown in fig. 2.

3) Cyanuric chloride and DSD acid sodium salt are fed according to a molar ratio of 2.

4) Feeding the intermediate B prepared in the step 2) and the intermediate C prepared in the step 3) according to a molar ratio of 4 ₁ Methyl group) and the structure thereof is analyzed by nuclear magnetic hydrogen spectroscopy, and the spectrum is shown in fig. 4.

Preparing an ABS emulsion type antioxidant composition:

20 parts of deionized water and 6 parts of potassium oleate emulsifier are put into a reactor and rapidly stirred and mixed for 5min at 25 ℃;

then adding 30 parts of the prepared hindered phenol antioxidant and 10 parts of alpha-lipoic acid into a reactor, and stirring at 75 ℃ for 10min to obtain an emulsion;

then adding 80 parts of deionized water, stirring at 75 ℃ for 10min, and diluting the system;

and finally, adding 1 part of polyvinyl alcohol and 0.1 part of tributyl phosphate defoaming agent, and stirring at 60 ℃ to react for 5min to obtain the ABS emulsion type antioxidant composition.

Example 2

Preparing hindered phenol antioxidant, comprising the following steps:

1) Feeding 2, 6-tert-butyl-p-cresol and butane according to a molar ratio of 1.2, adding a palladium chloride catalyst accounting for 1wt% of the mass of the 2, 6-tert-butyl-p-cresol, and carrying out dehydrogenation reaction at 170 ℃ for 6h to generate an intermediate A (a substituent R in the formula) ₂ Is propyl, i.e. 2, 6-tert-butyl-p-alkenylpentylphenol);

2) Illuminating with a light source with illumination intensity of 400lx and wavelength of 700nmInjecting the intermediate A generated in the step 1) at 90 ℃ according to a molar ratio of 3:1, introducing iodine simple substance, performing halogenation reaction at 90 ℃ for 5 hours, then adding 6wt% potassium hydroxide aqueous solution (the molar ratio of water to the intermediate A is 40: 1), and performing hydrolysis reaction at 40 ℃ for 4 hours to obtain an intermediate B (a substituent R in the formula ₁ Is propyl, i.e. 2, 6-tert-butyl-p-alkenylpentylenol);

3) Feeding cyanuric chloride and a DSD acid sodium salt according to a molar ratio of 1;

4) Feeding the intermediate B prepared in the step 2) and the intermediate C prepared in the step 3) according to a molar ratio of 1 ₁ Is propyl).

Preparing an ABS emulsion type antioxidant composition:

20 parts of deionized water and 8 parts of disproportionated potassium rosinate emulsifier are put into a reactor and rapidly stirred and mixed for 3min at 25 ℃;

then adding 40 parts of the prepared hindered phenol antioxidant and 8 parts of alpha-lipoic acid into a reactor, and stirring for 15min at 60 ℃ to obtain an emulsion;

then 100 parts of deionized water is added and stirred for 7min at 60 ℃ to dilute the system;

and finally, adding 0.5 part of polyvinyl alcohol and 0.5 part of tributyl phosphate defoaming agent, and stirring and reacting for 7min at 60 ℃ to obtain the ABS emulsion type antioxidant composition.

Example 3

Preparing hindered phenol antioxidant, comprising the following steps:

1) 2, 6-tert-butyl-p-cresol and ethane are fed according to the molar ratio of 1.2, then a rhodium chloride catalyst accounting for 1.5wt% of the mass of the 2, 6-tert-butyl-p-cresol is added, and then dehydrogenation reaction is carried out for 10 hours at 175 ℃ to generate an intermediate A (a substituent R in the formula) ₂ Is methyl, i.e., 2, 6-tert-butyl-p-allylphenol);

2) Irradiating the intermediate A generated in the step 1) at 80 ℃ under the irradiation of a light source with the illumination intensity of 100lx and the wavelength of 400nm, wherein the molar ratio of the intermediate A to the intermediate A is 1.5:1 introduction intoChlorine, halogenating reaction at 80 ℃ for 10h, then adding 10wt% sodium hydroxide aqueous solution (wherein the molar ratio of water to the intermediate A is 100 ₁ Is methyl, i.e., 2, 6-tert-butyl-p-allyloxyphenol);

3) Feeding cyanuric chloride and a DSD acid sodium salt according to a molar ratio of 5;

4) Feeding the intermediate B prepared in the step 2) and the intermediate C prepared in the step 3) according to a molar ratio of 3 ₁ Is methyl).

Preparing an ABS emulsion type antioxidant composition:

putting 10 parts of deionized water and 10 parts of potassium oleate emulsifier into a reactor, and quickly stirring and mixing for 2min at 25 ℃;

then adding 20 parts of the prepared hindered phenol antioxidant and 4 parts of alpha-lipoic acid into a reactor, and stirring at 90 ℃ for 5min to obtain an emulsion;

then adding 110 parts of deionized water, stirring at 90 ℃ for 3min and diluting the system;

and finally, adding 1.5 parts of polyvinyl alcohol and 0.2 part of octyl phosphate defoaming agent, and stirring and reacting for 5min at 90 ℃ to obtain the ABS emulsion type antioxidant composition.

Example 4

Preparing hindered phenol antioxidant, comprising the following steps:

1) Feeding 2, 6-tertiary butyl-p-cresol and pentane according to a molar ratio of 1 ₂ Is butyl, i.e., 2, 6-tert-butyl-p-alkenylhexylphenol);

2) Irradiating the intermediate A generated in the step 1) at 100 ℃ under the light source with the illumination intensity of 1000lx and the wavelength of 800nm, wherein the molar ratio of the intermediate A to the intermediate A is 1:1 introduction of chlorine, halogenation at 100 ℃ for 6h, and then addition of a 10% strength by weight aqueous sodium hydroxide solution (which isThe molar ratio of water to intermediate a in (1) is 20: 1) Hydrolyzing at 20 deg.C for 6h to obtain intermediate B (substituent R in the formula) ₁ Is butyl, i.e. 2, 6-tert-butyl-p-alkenylhexylenol);

3) Feeding cyanuric chloride and a DSD acid sodium salt according to a molar ratio of 2;

4) Feeding the intermediate B prepared in the step 2) and the intermediate C prepared in the step 3) according to a molar ratio of 3 ₁ Is butyl).

Preparing an ABS emulsion type antioxidant composition:

placing 15 parts of deionized water and 12 parts of sodium dodecyl sulfate emulsifier into a reactor, and quickly stirring and mixing for 8min at 25 ℃;

then adding 10 parts of the prepared hindered phenol antioxidant and 2 parts of alpha-lipoic acid into a reactor, and stirring at 80 ℃ for 15min to obtain an emulsion;

then 65 parts of deionized water is added and stirred for 10min at 80 ℃ to dilute the system;

and finally, adding 0.5 part of polyvinyl alcohol and 0.15 part of octyl phosphate defoaming agent, and stirring and reacting at 80 ℃ for 10min to obtain the ABS emulsion type antioxidant composition.

Example 5

Preparing hindered phenol antioxidant, comprising the following steps:

1) Feeding 2, 6-tert-butyl-p-cresol and propane according to a molar ratio of 1.5, adding a palladium chloride catalyst accounting for 3wt% of the mass of 2, 6-tert-butyl-p-cresol, and carrying out dehydrogenation reaction at 180 ℃ for 5h to generate an intermediate A (a substituent R in the formula) ₂ Is ethyl, i.e. 2, 6-tert-butyl-p-alkenylbutylphenol);

2) Irradiating the intermediate A generated in the step 1) at 70 ℃ under the irradiation of a light source with the illumination intensity of 800lx and the wavelength of 650nm according to the molar ratio of 2:1 introducing bromine, halogenating at 70 ℃ for 7h, adding a 7wt% potassium hydroxide aqueous solution (the molar ratio of water to the intermediate A is 60: 1), hydrolyzing at 30 ℃ for 5h,to obtain an intermediate B (in the formula, a substituent R) ₁ Is ethyl, i.e. 2, 6-tert-butyl-p-alkenylbutylphenol);

3) Feeding cyanuric chloride and a DSD acid sodium salt according to a molar ratio of 2;

4) Feeding the intermediate B prepared in the step 2) and the intermediate C prepared in the step 3) according to a molar ratio of 6 ₁ Is ethyl).

Preparing an ABS emulsion type antioxidant composition:

30 parts of deionized water and 1 part of potassium oleate emulsifier are put into a reactor and rapidly stirred and mixed for 6min at 65 ℃;

then adding 40 parts of the prepared hindered phenol antioxidant and 6 parts of alpha-lipoic acid into a reactor, and stirring at 65 ℃ for 15min to obtain an emulsion;

then 50 parts of deionized water is added and stirred for 3min at 65 ℃ to dilute the system;

and finally, adding 2 parts of polyvinyl alcohol and 0.3 part of tributyl phosphate defoaming agent, and stirring and reacting for 5min at 65 ℃ to obtain the ABS emulsion type antioxidant composition.

Comparative example 1

Based on the ABS emulsion antioxidant composition in example 1, the difference is only that: selecting a molar ratio of 1:2, 6-tert-butyl p-allylphenol and 1 molar part of triazine amino stilbene type fluorescent whitening agent mixture, replacing the hindered phenol type antioxidant prepared in the example 1 by equal mass, and keeping other parameters and operation unchanged to prepare the ABS emulsion type antioxidant composition

Comparative example 2

Based on the ABS emulsion antioxidant composition in example 1, the difference is only that: and replacing the hindered phenol antioxidant prepared in the example 1 with the intermediate A and other parameters and operations, and thus obtaining the ABS emulsion antioxidant composition.

Comparative example 3

Based on the ABS emulsion antioxidant composition in example 1, the differences are only that: and replacing the hindered phenol antioxidant in the example 1 with the intermediate C and other mass, and keeping other parameters and operation unchanged to prepare the ABS emulsion antioxidant composition.

Comparative example 4

Based on the ABS emulsion antioxidant composition in example 1, the difference is only that: the addition amount of the alpha-lipoic acid is 0, and other parameters and operations are unchanged, so that the ABS emulsion type antioxidant composition is prepared.

Comparative example 5

Based on the ABS emulsion antioxidant composition in example 1, the difference is only that: and (3) not adding an emulsifier, and keeping other parameters and operations unchanged to prepare the ABS emulsion type antioxidant composition.

Comparative example 6

Referring to the preparation method of hindered phenol antioxidant of example 1, the difference is only that: replacing 2, 6-tert-butyl-p-cresol in the step 1) with 2, 4-dimethyl-6-tert-butylphenol, and keeping other parameters and operation unchanged to prepare a compound;

then, the obtained mixture was equally substituted for the hindered phenol antioxidant prepared in example 1, and other parameters and operations were not changed to prepare an emulsion type composition.

Comparative example 7

Referring to the preparation method of hindered phenol antioxidant of example 1, the difference is only that: omitting step 2), directly and uniformly mixing the intermediate A and the intermediate C in the step 1) into a composition;

then, the obtained mixture was equally substituted for the hindered phenol antioxidant prepared in example 1, and other parameters and operations were not changed to prepare an emulsion type composition.

Comparative example 8

Referring to the preparation method of hindered phenol antioxidant of example 1, the difference is only that: omitting steps 1) and 2), directly and uniformly mixing 2, 6-tert-butyl-p-cresol with the intermediate C to obtain a composition;

then, the obtained mixture was equally substituted for the hindered phenol antioxidant prepared in example 1, and other parameters and operations were not changed to prepare an emulsion type composition.

According to the method disclosed in 'ABS resin production practice and application' in the literature, the emulsion antioxidant compositions prepared in the examples and the comparative examples are added into ABS grafted latex according to the following steps to prepare ABS rubber powder, and the ABS rubber powder is blended with SAN resin, extruded and injection-molded into a test sample strip for testing:

1) Preparation of ABS rubber powder

100kg of ABS graft latex is heated to 45 ℃ in a reaction kettle, 7kg of the emulsion antioxidant composition prepared in the embodiment and the comparative example are added, and stirring is started for 30min to be uniformly mixed.

2kg MgSO 2 was added to the coagulation kettle ₄ 200kg of deionized water and stirring was switched on MgSO ₄ Fully dissolving, heating a condensation kettle to 75 ℃, respectively adding 100kg of the ABS graft latex mixture into the condensation kettle in a continuous feeding mode, wherein the continuous feeding time is 1 hour, heating the condensation kettle to 90 ℃ after the feeding is finished, keeping the temperature for 1 hour, cooling the condensation kettle to normal temperature, filtering, washing and dehydrating the condensation slurry to obtain ABS wet rubber powder, and drying the ABS wet rubber powder to the water content at 65 ℃ by using a fluidized bed dryer<1% to obtain ABS rubber powder.

And (3) respectively carrying out S element analysis on the ABS rubber powder, determining the content of the antioxidant in the rubber powder, and testing the content of residual monomers of acrylonitrile, styrene and butadiene in the ABS rubber powder by adopting a headspace gas phase method.

2) Preparation, injection molding and performance test of ABS resin

Adopting a double-screw extruder, taking SAN resin with LG chemical grade SA 30 as a blending continuous phase at 200-220 ℃, taking ABS rubber powder prepared in step 1) as a blending dispersed phase, and respectively performing blending extrusion and granulation according to the feeding ratio of 30 parts of rubber powder and 70 parts of SAN resin to obtain the ABS resin.

Various test bars are prepared on the ABS resin on an injection molding machine at 210 ℃, and the b value, the impact strength, the tensile strength and the bending strength of the ABS resin are respectively obtained by testing according to ASTM D1925, ASTM D256, ASTM D638-2000 and ASTM D790-2000 standards.

TABLE 1 ABS rubber powder residue test results for the examples and comparative examples

/>

Table 2 whiteness and mechanical property test results of ABS rubber powder prepared in examples and comparative examples

/>

As can be seen from the test results of examples 1-5 and comparative examples 1-8, the ABS rubber powder prepared from the emulsion antioxidant composition prepared by the invention has less residue compared with the ABS rubber powder prepared from the emulsion antioxidant composition prepared by the comparative examples.

As can be seen from the test results of examples 1 to 5 and comparative examples 1 to 8, the ABS resin prepared from the emulsion antioxidant composition prepared by the invention has better mechanical properties, low odor and lower b value which is less than 10 compared with the ABS resin prepared from the emulsion antioxidant composition prepared by the comparative example.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims (10)

1. A hindered phenol antioxidant having a structure represented by formula (1):

in the formula, R ₁ is-C _n H _2n -，n＝1-4。

2. A method for preparing the hindered phenol antioxidant of claim 1, comprising the steps of:

1) Carrying out dehydrogenation reaction on 2, 6-tert-butyl-p-cresol and alkane under the action of a catalyst to generate an intermediate A;

2) Heating the intermediate A prepared in the step 1) and halogen under the illumination condition for halogenation, and then adding an aqueous alkali solution for hydrolysis reaction to generate an intermediate B;

3) Cyanuric chloride and 4,4 '-diaminostilbene-2, 2' -disulfonic acid sodium salt are subjected to condensation reaction to generate an intermediate C;

4) And carrying out substitution reaction on the intermediate C prepared in the step 3) and the intermediate B prepared in the step 2) to prepare the hindered phenol antioxidant shown in the formula (1).

3. The production method according to claim 2, wherein in step 1), the alkane structure is CH ₃ -R ₂ Wherein R is ₂ is-C _n H _2n+1 ，n＝1-4；

The catalyst is selected from one or more of platinum, rhodium and palladium catalysts, preferably one or more of platinum, rhodium and palladium chloride; and/or

In the step 1), the molar ratio of the 2, 6-tert-butyl-p-cresol to the alkane is 1:0.5-1:2, preferably 1:1.2-1:1.5;

the amount of the catalyst is 0.5-3%, preferably 1-2% of the mass of 2, 6-tert-butyl-p-cresol; and/or

In the step 1), the dehydrogenation reaction is carried out at the temperature of 170-190 ℃, preferably 170-180 ℃; the time is 4 to 10 hours, preferably 5 to 7 hours; and/or

In the step 1), the structure of the intermediate A is shown as a formula (2):

in the formula, R ₂ is-C _n H _2n+1 ，n＝1-4。

4. The method according to claim 2 or 3, wherein in step 2), the halogen is selected from chlorine, bromine, iodine, preferably chlorine;

the molar ratio of the intermediate A to the halogen is 1-3:1, preferably 1.5-2:1; and/or

In the step 2), the halogenation reaction is carried out under the illumination condition, the illumination intensity is 100-1000lx, and the wavelength is 400-800nm;

the halogenation reaction is carried out at the temperature of 70-100 ℃, preferably at the temperature of 90-100 ℃; the time is 5 to 10 hours, preferably 6 to 8 hours; and/or

In the step 2), the alkali aqueous solution is selected from one or more of metal hydroxide aqueous solutions, preferably at least one of sodium hydroxide and potassium hydroxide aqueous solutions;

preferably, the aqueous base concentration is from 5 to 10wt%, preferably from 5 to 7wt%;

the molar ratio of the intermediate A to water in the aqueous alkali solution is 1:20-100, preferably 1:30-60 parts of; and/or

In the step 2), the hydrolysis reaction is carried out at the temperature of 20-50 ℃, preferably 25-40 ℃; the time is 2 to 6 hours, preferably 3 to 5 hours; and/or

In the step 2), the structure of the intermediate B is shown as a formula (3):

in the formula, R ₁ is-C _n H _2n -，n＝1-4。

5. The process according to any one of claims 2 to 4, wherein in step 3), the molar ratio of cyanuric chloride to the sodium salt of 4,4 '-diaminostilbene-2, 2' -disulfonic acid is 5 to 1:1, preferably 2-1:1; and/or

In the step 3), the condensation reaction is carried out at the temperature of-3-3 ℃, preferably 0-2 ℃; the time is 1-6h, preferably 2-4h;

controlling the pH value of a reaction system to be 3-4 in the condensation reaction process, and preferably adopting sodium carbonate to regulate the pH value; and/or

In the step 3), the intermediate C has a structure shown in a formula (4):

6. the process according to any one of claims 2 to 5, wherein in step 4), the molar ratio of intermediate C to intermediate B is 1:1-6 preferably 1:3-5; and/or

In the step 4), the temperature of the substitution reaction is 50-90 ℃, and preferably 65-90 ℃; the time is 4 to 9 hours, preferably 6 to 8 hours;

in the process of the substitution reaction, the pH value of the reaction system is controlled to be 3-7, and is preferably regulated and controlled by sodium carbonate.

7. An ABS emulsion type antioxidant composition, which is characterized by comprising the hindered phenol antioxidant of claim 1 or the hindered phenol antioxidant prepared by the preparation method of any one of claims 2 to 6 and alpha-lipoic acid;

preferably, the mass ratio of the hindered phenol antioxidant to the alpha-lipoic acid is 5-1:1, preferably 4-2;

preferably, the ABS emulsion antioxidant composition comprises other auxiliary agents selected from one or more of an emulsifier, a thickener, a defoaming agent and water.

8. The ABS emulsion antioxidant composition as claimed in claim 7, wherein the composition comprises, in parts by weight:

10-40 parts of hindered phenol antioxidant, preferably 30-40 parts;

2-20 parts of alpha-lipoic acid, preferably 10-15 parts;

1-12 parts of emulsifier, preferably 5-10 parts;

0-2 parts of thickening agent, preferably 0-1 part;

0-0.3 part of defoaming agent, preferably 0-0.2 part;

80-120 parts of water, preferably 80-100 parts of water.

9. A method for preparing the ABS emulsion antioxidant composition as claimed in claim 7 or 8, which comprises the following steps:

s1: mixing part of water and emulsifier under stirring;

s2: adding hindered phenol antioxidant shown in formula (1) and alpha-lipoic acid into the S1 system, and stirring to obtain emulsion;

s3: adding a residual water dilution system into the S2 emulsion;

s4: adding a thickening agent and a defoaming agent into the S3 system, and uniformly mixing to obtain an ABS emulsion type antioxidant composition;

preferably, in the step S1, the mixture is stirred for 2-8min at normal temperature and pressure;

preferably, the emulsification process of the step S2 is carried out at the temperature of 60-90 ℃ and the stirring is carried out for 5-15min under normal pressure;

preferably, the dilution process of the step S3 is carried out at the temperature of 60-90 ℃, and the mixture is stirred for 3-10min under normal pressure;

preferably, the mixing process in the step S4 is carried out at the temperature of 60-90 ℃ and the stirring time is 5-10min under normal pressure;

preferably, the water is added in two times during the preparation process, wherein 10-30 parts of water is added in step S1, and the rest of water is added in step S3.

10. An ABS resin, which is characterized by being prepared from the ABS emulsion type antioxidant composition as claimed in claim 7 or 8;

preferably, the ABS emulsion antioxidant composition is added in an amount of 3-12wt%, preferably 5-10wt%, based on the total mass of the ABS resin.

Images