Compound polymerization inhibitor for refining butyl methacrylate and application thereof

Abstract

The invention discloses a compound polymerization inhibitor for refining butyl methacrylate and application of the compound polymerization inhibitor. Effective components of the pesticide composition comprise a component A, a component B and a component C, the component A comprises a copper salt compound, the component B comprises an amine compound, and the component C comprises a phosphite ester compound. The component A, the component B and the component C provided by the invention are dissolved in an organic solvent, can be prepared into a polymerization inhibitor solution, can be conveniently added into a butyl methacrylate refining device, and can be easily dissolved in a polymerization-inhibited raw material to form a uniform solvent system, so that a very good lubricating effect can be achieved, and the accumulation of a polymer in the device is effectively prevented. The multifunctional efficient polymerization inhibitor provided by the invention is excellent in polymerization inhibition performance, polymerization of butyl methacrylate can be effectively inhibited by using a small amount of the multifunctional efficient polymerization inhibitor, long-period safe and stable operation of a butyl methacrylate production device can be ensured, the operation period of the production device is prolonged, and the comprehensive performance of the multifunctional efficient polymerization inhibitor is superior to the performance of a single polymerization inhibitor in the industry at present.

Description

Technical Field

[0001] The present invention relates to a compound polymerization inhibitor for the purification of butyl methacrylate and its application. Background Art

[0002] Butyl methacrylate can be used as a comonomer of butyl methacrylate for the production of modified polymethyl methacrylate. Its butyl group is larger than the methyl group of MMA, which can increase the flexibility and impact resistance of the polymer and is suitable for manufacturing high-impact transparent sheets, bulletproof glass interlayers, etc. In addition, it can also be used in the production of functional resins, coatings and adhesives, biomedical materials, textile and papermaking auxiliaries and other fields.

[0003] The molecular structure of butyl methacrylate has unstable double bond functional groups, which are extremely prone to chemical reactions such as self-polymerization, copolymerization or hydrolysis, bringing certain difficulties to production, transportation and storage. In addition, the butyl methacrylate industry belongs to a high-risk industry, and industrial hazard incidents such as fires and explosions caused by polymerization due to overheating occur frequently. The deposition of polymerization products will cause pipeline blockage, resulting in reduced heat exchange efficiency, reduced throughput and even forced shutdown. In order to prevent the blockage of equipment and pipelines in the production of butyl methacrylate and ensure the smooth progress of production, a certain amount of polymerization inhibitor must be added during the production process to prevent its polymerization.

[0004] At present, the main polymerization inhibitors used in the production of butyl methacrylate are divided into two categories: one is the chain transfer type, mainly including hydroquinone, hydroquinone monomethyl ether, phenothiazine, etc.; the other is the metal salt type, mainly including copper acetate, copper dibutyldithiocarbamate, etc. In terms of the current situation of using polymerization inhibitors in butyl methacrylate monomer production plants, except for the known synergistic effect of hydroquinone and phenothiazine, most are single polymerization inhibitors acting. Due to the synergistic effect of compound polymerization inhibitors, the polymerization inhibition effects of the compound two-component and three-component polymerization inhibitors are better than those of single-component polymerization inhibitors.

[0005] Although the existing compound polymerization inhibitors applied in the production process of methacrylates have improved polymerization inhibition effects compared with the use of single-component polymerization inhibitors, they still cannot avoid polymer fouling and adhesion on distillation and purification equipment, and have a relatively large dosage and low polymerization inhibition efficiency. Summary of the Invention

[0006] The multifunctional and highly efficient polymerization inhibitor provided by the present invention has excellent polymerization inhibition performance. A small amount of dosage can effectively inhibit the polymerization of butyl methacrylate, ensure the long-term safe and stable operation of the butyl methacrylate production device, extend the operation cycle of the production device, and its comprehensive performance is better than that of the current single polymerization inhibitor in industry.

[0007] The present invention uses copper compounds, amine compounds, and phosphite compounds as raw materials to obtain a ternary compounding inhibitor through compounding, and applies it to the production process of butyl methacrylate to achieve an inhibition effect and extend the induction period of the inhibition reaction.

[0008] Preferably, the mass ratio of the copper salt compounds, amine compounds, and phosphite compounds is 1-50:1-30:1-30. Further preferably, the mass ratio of the copper salt compounds, amine compounds, and phosphite compounds is (40-70):(10-60):(10-60).

[0009] Preferably, the copper salt compound is one of copper 8-hydroxyquinoline salt, copper monobutyl phthalate complex, copper isooctanoate, and copper acetate.

[0010] Preferably, the amine compound is one of 2-methyl-5-dimethylamino-4-chlorohexane, tetramethylammonium hydroxide, and N,N-dimethyl-p-methylaniline.

[0011] Preferably, the phosphite compound is tribenzyl phosphite, tris(nonylphenyl) phosphite, or bis(2-ethylhexyl) phosphite.

[0012] Preferably, the component D includes one of trichloroethylene, glycerol triglycidyl ether, and triethanolamine. Preferably, components A, B, and C are all dissolved in component D.

[0013] The high-efficiency compounding inhibitor of the present invention is used to inhibit the polymerization of butyl methacrylate; preferably used in the vacuum distillation process of butyl methacrylate, and the pressure of the vacuum distillation process is preferably 1-40 kPa, and the temperature is preferably 95-120 °C.

[0014] The beneficial effects of the present invention are as follows:

[0015] The compounding inhibitor provided by the present invention includes components A, B, and C dissolved in an organic solvent, and can be formulated into an inhibitor solution for easy addition to the butyl methacrylate refining device and is easily soluble in the inhibited raw materials, forming a uniform solvent system, which can play a good lubricating role and effectively prevent the accumulation of polymers in the device. In the compounding inhibitor, the addition of copper salt compounds effectively promotes charge transfer, the participation of phosphite compounds reduces the consumption of amine compounds, and the amine compounds themselves can be regenerated by means of a synergistic effect. It is precisely due to the synergistic effect between components that the effective concentration of the compounding inhibitor is guaranteed, thereby extending the inhibition period. More importantly, the present invention has no adverse effects on subsequent products and also has the advantage of low cost.

[0016] The multifunctional and highly efficient polymerization inhibitor provided by the present invention has excellent polymerization inhibition performance, and a small amount of it can effectively inhibit the polymerization of butyl methacrylate, which can ensure the long-term safe and stable operation of the butyl methacrylate production unit, extend the operation cycle of the production unit, and its comprehensive performance is superior to that of the single polymerization inhibitor currently used in industry. Detailed Embodiments

[0017] The present invention will be illustrated by specific examples, but the content of the present invention is not limited to these examples. All percentages in the text are mass percentages, and the unit ppm is expressed in terms of mass.

[0018] Examples 1 - 11:

[0019] Taking the crude butyl methacrylate material entering the refining unit as an example. In a 10 ml glass tube, 59.3% of butyl methacrylate, 14.9% of acetic acid, 10.6% of water, 8.8% of n-propanol and a small amount of acetone were loaded. Then, 100 ppm of a polymerization inhibitor and 0.1% of azobisisobutyronitrile were added to the reaction test tube, and it was placed in a constant temperature water bath at 95 °C. Samples were taken at regular intervals, and when the refractive index of butyl methacrylate changed, the polymerization inhibition time was recorded. Copper 8-hydroxyquinoline salt, copper monobutyl phthalate complex, copper isooctanoate, copper acetate, 2-methyl-5-dimethylamino-4-chlorohexane, tetramethylammonium hydroxide, N,N-dimethyl-p-toluidine, tribenzyl phosphite, tris(nonylphenyl) phosphite, bis(2-ethylhexyl) phosphite were used as polymerization inhibitors. The results are shown in Table 1.

[0020] Table 1 Polymerization inhibition effect of single polymerization inhibitor on butyl methacrylate samples (the solvent is 20% trichloroethylene, and the solvents in the examples are added separately as carriers)

[0021] Example Polymerization inhibitor Turbidity or explosion polymerization time (min) 1 Without polymerization inhibitor 17 2 Copper 8-hydroxyquinoline salt 97 3 Copper monobutyl phthalate complex 85 4 Copper isooctanoate 80 5 Copper acetate 74 6 2-Methyl-5-dimethylamino-4-chlorohexane 50 7 Tetramethylammonium hydroxide 76 8 N,N-Dimethyl-p-toluidine 60 9 Tribenzyl phosphite 67 10 Tris(nonylphenyl) phosphite 84 11 Bis(2-ethylhexyl) phosphite 76

[0022] As can be seen from Table 1, compared with the raw material without adding a polymerization inhibitor, after adding the polymerization inhibitor provided by the present application, the polymerization time of the material is significantly extended, and all the added polymerization inhibitors have good polymerization inhibition performance. Among them, the best polymerization inhibition effect is shown by copper 8-hydroxyquinoline salt, and the worst is 2-methyl-5-dimethylamino-4-chlorohexane.

[0023] Examples 12 - 34

[0024] Take the crude butyl methacrylate material entering the refining unit as an example. In a 10 ml glass tube, 59.3% butyl methacrylate, 14.9% acetic acid, 10.6% water, 8.8% n-propanol and a small amount of acetone were loaded. Then, 100 ppm of a two-component inhibitor and 0.1% azobisisobutyronitrile were added to the reaction tube, and it was placed in a constant temperature water bath at 95 °C. Samples were taken at regular intervals, and when the refractive index of butyl methacrylate changed, the inhibition time was recorded. The results are shown in Table 3.

[0025] Table 2 Two-component inhibitor formulation for butyl methacrylate

[0026]

[0027] Among them, A1 is copper 8-hydroxyquinoline salt, A2 is copper monobutyl phthalate complex, A3 is copper isooctanoate copper acetate, A4 is copper acetate, B1 is 2-methyl-5-dimethylamino-4-chlorohexane, B2 is tetramethylammonium hydroxide, B3 is N,N-dimethyl-p-methylaniline, C1 is tribenzyl phosphite, C2 is tris(nonylphenyl) phosphite, C3 is bis(2-ethylhexyl) phosphite.

[0028] Table 3 Inhibition effect of two-component inhibitor on butyl methacrylate

[0029] Polymerization inhibitor Polymerization inhibition time (min) Polymerization inhibitor of Example 12 85 Polymerization inhibitor of Example 13 84 Polymerization inhibitor of Example 14 89 Polymerization inhibitor of Example 15 90 Polymerization inhibitor of Example 16 90 Polymerization inhibitor of Example 17 84 Polymerization inhibitor of Example 18 90 Polymerization inhibitor of Example 19 85 Polymerization inhibitor of Example 20 99 Polymerization inhibitor of Example 21 105 Polymerization inhibitor of Example 22 75 Polymerization inhibitor of Example 23 61 Polymerization inhibitor of Example 24 85 Polymerization inhibitor of Example 25 102 Polymerization inhibitor of Example 26 88 Polymerization inhibitor of Example 27 95 Polymerization inhibitor of Example 28 75 Polymerization inhibitor of Example 29 65 Polymerization inhibitor of Example 30 75 Polymerization inhibitor of Example 31 65 Polymerization inhibitor of Example 32 72 Polymerization inhibitor of Example 33 59 Polymerization inhibitor of Example 34 77

[0030] As can be seen from Table 3, the inhibition effect of the compounded two-component inhibitor is improved to a certain extent compared with that of the single inhibitor. Among them, the best compounding formula is copper monobutyl phthalate complex: tribenzyl phosphite = 55:45, and the inhibition time reaches 105 min.

[0031] Examples 35 - 50

[0032] Take the crude butyl methacrylate material entering the refining unit as an example. In a 10 ml glass tube, 59.3% butyl methacrylate, 14.9% acetic acid, 10.6% water, 8.8% n-propanol and a small amount of acetone were loaded. Then, 100 ppm of a three-component inhibitor and 0.1% azobisisobutyronitrile were added to the reaction tube, and it was placed in a constant temperature water bath at 95 °C. Samples were taken at regular intervals, and when the refractive index of butyl methacrylate changed, the inhibition time was recorded. The results are shown in Table 5.

[0033] Table 4 Three-component inhibitor formulation for butyl methacrylate

[0034]

[0035] Among them, A1 is copper 8-hydroxyquinoline salt, A2 is copper monobutyl phthalate complex salt, A3 is copper isooctanoate copper acetate, A4 is copper acetate, B1 is 2-methyl-5-dimethylamino-4-chlorohexane, B2 is tetramethylammonium hydroxide, B3 is N,N-dimethyl-p-methylaniline, C1 is tribenzyl phosphite, C2 is tris(nonylphenyl) phosphite, and C3 is bis(2-ethylhexyl) phosphite. The results are shown in Table 5.

[0036] Table 5 Inhibiting effect of three-component inhibitor on butyl methacrylate samples

[0037]

[0038]

[0039] As can be seen from Table 5, due to the high-level synergistic effect among the components of the three-component inhibitor, its inhibiting effect is significantly improved compared with the two-component inhibitor. Among them, the best compounding effect is the compounding of copper monobutyl phthalate complex salt, tetramethylammonium hydroxide, and tris(nonylphenyl) phosphite. When the ratio of the three is 50:25:25, the inhibiting effect is the best, and the inhibition time reaches 113 min. The copper monobutyl phthalate complex salt in this formula has a relatively low industrial price and can effectively capture highly active free radicals. The synergistic effect among the compounded inhibitors significantly reduces the probability of free radical escape. In addition, all three are easily soluble in common organic solvents, which is convenient for uniform dispersion and accurate addition.

[0040] Comparative Examples 51-62

[0041] Taking the crude butyl methacrylate material entering the refining device as an example. In a 10 ml glass tube, 59.3% butyl methacrylate, 14.9% acetic acid, 10.6% water, 8.8% n-propanol, and a small amount of acetone were loaded. Then, 100 ppm of the three-component inhibitor (using the inhibitor formula described in Patent CN104370730A) and 0.1% azobisisobutyronitrile were added to the reaction test tube. It was placed in a constant temperature water bath at 95 °C, and samples were taken at regular intervals. When the refractive index of butyl methacrylate changed, the inhibition time was recorded. The results are shown in Table 7.

[0042] Table 6 Three-component inhibitor formula for butyl methacrylate

[0043]

[0044]

[0045] Among them, A1 is p-cresol, A2 is 2,6-di-tert-butylphenol, A3 is 2,4-dimethyl-6-tert-butylphenol, A4 is 4-methyl-2,6-di-tert-butylphenol, B1 is phenothiazine, B2 is 2,2,4-trimethyl-1,2-dihydroquinoline, B3 is N-phenyl-β-naphthylamine, C1 is copper dibutyldithiocarbamate, C2 is copper naphthenate, and C3 is copper oleate.

[0046] Table 7 Inhibiting effect of three-component inhibitor on butyl methacrylate

[0047] Polymerization inhibitor Polymerization inhibition time (min) Polymerization inhibitor of Example 51 70 Polymerization inhibitor of Example 52 84 Polymerization inhibitor of Example 53 73 Polymerization inhibitor of Example 54 85 Polymerization inhibitor of Example 55 80 Polymerization inhibitor of Example 56 79 Polymerization inhibitor of Example 57 80 Polymerization inhibitor of Example 58 91 Polymerization inhibitor of Example 59 93 Polymerization inhibitor of Example 60 78 Polymerization inhibitor of Example 61 79 Polymerization inhibitor of Example 62 86

[0048] As can be seen from Table 7, when p-cresol:phenothiazine:copper dibutyldithiocarbamate = 70:15:15, the inhibiting effect is the best, and the inhibition time is 93 min. However, its inhibiting effect is not as good as the best formula of the present invention.

[0049] From the above inhibitor evaluation experiments, it can be seen that the use of the compound inhibitor of the present invention has an obvious inhibitory effect on the polymerization of butyl methacrylate, can significantly extend the operation cycle of the production device for refining butyl methacrylate, and in addition, the raw material cost is relatively low.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite polymerization inhibitor for refining butyl methacrylate, characterized in that: The invention comprises component A, component B and component C, wherein component A comprises a copper salt compound, component B comprises an amine compound, and component C comprises a phosphite compound.

2. The composite polymerization inhibitor for refining butyl methacrylate according to claim 1, characterized in that: The mass ratio of component A, component B and component C is (1-100):(1-80):(1-80).

3. The composite polymerization inhibitor for refining butyl methacrylate according to claim 1, characterized in that: The mass ratio of component A, component B and component C is (40-70):(10-60):(10-60).

4. A composite polymerization inhibitor for refining butyl methacrylate according to claim 2 or 3, characterized in that: The copper salt compound is one of 8-hydroxyquinoline copper salt, monobutyl phthalate copper salt, copper isooctanoate and copper acetate.

5. The composite polymerization inhibitor for refining butyl methacrylate according to claim 4, characterized in that: The amine compound is one of 2-methyl-5-dimethylamino-4-chlorohexane, tetramethylammonium hydroxide and N,N-dimethyl-p-methylaniline.

6. A composite polymerization inhibitor for refining butyl methacrylate according to claim 5, characterized in that: The phosphite compound is one of tribenzyl phosphite, tris(nonylphenyl)phosphite and bis(2-ethylhexyl)phosphite.

7. The composite polymerization inhibitor for refining butyl methacrylate according to claim 5, characterized in that: The invention also comprises a component D, wherein the component D comprises one of trichloroethylene, glycerol triglycidyl ether and triethanolamine. Preferably, the component A, the component B and the component C are all dissolved in the component D.

8. The use of any one of the composite polymerization inhibitors for refining butyl methacrylate according to claims 5-7, characterized in that: The compound polymerization inhibitor is used for inhibiting the polymerization of butyl methacrylate.

9. The use of any one of the compound polymerization inhibitors for refining butyl methacrylate according to claims 5-7, characterized in that: The composite polymerization inhibitor is used in the negative pressure distillation process of butyl methacrylate, the pressure of the negative pressure distillation process is 1-40 kPa, and the temperature is preferably 95-120°C.

10. Use of the composite polymerization inhibitor for refining butyl methacrylate according to any one of claims 5 to 7, characterized in that: In the butyl methacrylate material, the total amount of the compound inhibitor added is 100-100000ppm, and the concentration is 100-2000ppm.

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