CN103665356B

CN103665356B - A kind of continuous processing prepares the method for polyester resin for powder coating

Info

Publication number: CN103665356B
Application number: CN201310602513.5A
Authority: CN
Inventors: 蒋云
Original assignee: Zhangjiagang Baotian New Material Science & Technology Co Ltd
Current assignee: Jiangsu Tian Bao new material Polytron Technologies Inc
Priority date: 2013-11-25
Filing date: 2013-11-25
Publication date: 2015-08-26
Anticipated expiration: 2033-11-25
Also published as: WO2015074622A1; CN103665356A

Abstract

The invention discloses a kind of method that continuous processing prepares thermoset saturated polyester resin used for powder coating, the steps include: in the presence of a catalyst, polyethylene terephthalate and boiling point carry out alcoholysis reaction higher than the dibasic alcohol of ethylene glycol, displace ethylene glycol, again through esterification, polyreaction, finally add trimellitic acid 1,2-anhydride, curing catalyst adjustment react epoxy/polyester mixed polyester resin used for powder coating or add curing catalyst adjustment react to obtain pure polyester type vibrin used for powder coating.The method is by the means of the aspects such as automatization adjust flux, temperature, pressure, real-time Automated condtrol and on-line monitoring are carried out to each process section, constant product quality, reduce material side reaction and hyperreactive possibility, plant factor is high, and equipment investment is low, achieve the compact of production unit, personnel's consumption is few, and production cost is low, save energy.

Description

A kind of continuous processing prepares the method for polyester resin for powder coating

Technical field

The present invention relates to a kind of preparation method of polyester resin for powder coating, be specifically related to adopt main raw material to be the method that polyethylene terephthalate (PET) or terephthalic acid (PTA) continuous process prepare thermoset saturated polyester resin used for powder coating.

Background technology

Thermosetting powder coating(s) is a kind of no-solvent type coating adopting electrostatic spraying heating and melting levelling film-forming, is a kind of application coating widely.

Thermosetting powder coating(s) saturated polyester resin is an important component of thermosetting powder coating(s), main point of epoxy/polyester mixed type (acid number is 20-100mgKOH/g) end carboxyl saturated polyester resin and by isocyanuric acid three-glycidyl ester (TGIC) or beta-hydroxy alkylamide (HAA) curing (acid number is 10-80mgKOH/g) end carboxyl pure polyester resin two classification greatly, the thermosetting powder coating(s) saturated polyester resin mainly esterification under the effect of catalyzer by polyvalent alcohol and polyprotonic acid, polycondensation forms.

The production method that current thermosetting powder coating(s) vibrin adopts is: material is completed several heating-cooling reaction process in a reactor after, finished product cooling discharge will be obtained again, the temperature reaction that feeds intake of next batch material is carried out again after the discharging of question response still, product and product batch between there is the batch production technique of interruption, main production operating process is as follows:

By the requirement of epoxy/polyester hybrid thermosetting saturated polyester resin formula, add neopentyl glycol, glycol ether etc. two, trivalent alcohol is to interior band heat supply and cool in the stainless steel inner container external jacket reactor of Stainless Steel Coil, start stirring and be progressively warming up to all dissolvings such as neopentyl glycol, drop into pure terephthalic acid, hexanodioic acid, the unclassified stores of the recipe requirements such as trimellitic acid 1,2-anhydride, progressively be warmed up to 100 DEG C, slightly stop the moisture got rid of in material, progressively heat up again, start esterification, the knockout tower tower top temperature controlling to be connected with reactor is at 100-105 DEG C, isolate tower top esterification water, continue heat supply the highest 260 DEG C to temperature of charge, to the minimizing of the amount that the esterification later stage produces along with esterification water, be separated the temperature reduction of tower top, sampling detects, record material at acid number 28mgKOH/g, viscosity 18cP(150 DEG C of detection), esterification terminates, progressively introduce negative pressure in still, to vacuum tightness 1000 ± 800Pa, time length is about 60min, after introducing nitrogen breaking vacuum to normal pressure, sampling detects, record acid number 12mgKOH/g, viscosity 12cP(200 DEG C of detection), be cooled to 200 DEG C, add the trimellitic acid 1,2-anhydride of recipe requirements, insulated and stirred reaction 60min, record acid number 70mgKOH/g, viscosity 23cP(200 DEG C of detection), be cooled to 180 DEG C, add 1816 curing catalysts of recipe requirements, stirring reaction 30min.Reaction terminate, logistics after filtration, extrusion reaction still, cooling, pulverize, packaging warehouse-in.

Above-mentioned interrupter method production technique also exists many-sided shortcoming, mainly:

1) during actual industrial production, material heating-cooling reaction in a reactor of several tons to tens of tons, due to many-sided factor such as thermal conduction, stirring, the heating-cooling of technique, artificial control of reactor, the overreact of material or hyporeactive reaction non-uniform phenomenon can be caused, cause in product batches and also there is quality wild effect; And control stiffness between product batches is poor, causes the quality index between product batches to fluctuate;

3) process of batch process synthesis, need to experience from normal temperature to 260 DEG C in a metallic reactors, cool to 180 DEG C as early as possible again, be warmed up to 260 DEG C again, cool to multiple heating-cooling technological processs such as 180 DEG C more as early as possible, due to requirements such as production efficiency and quality techniques, also must the time between heating-cooling operation be shortened better and better, interval heating-cooling institute swaps out the heat recycling difficulty come greatly, energy wastage;

4) in reactor, each original paper such as heat-transfer surface, interior heat exchange coil, heating agent pipeline, cooling duct, thermal-medium boiler, pump, valve, screw and nut fastening piece works throughout the year in the extreme environment that temperature is fluctuated, easily brings serious safety and the hidden danger of quality such as metal fatigue, leakage, cracking;

5) material generally will experience several hours wait cooling discharging processes at high operating temperatures after completion of the reaction, can cause the volatilization at high temperature of the materials such as curing catalyst, reduce quality product, the unordered discharge of chemical volatile matter simultaneously can cause environmental pollution;

6) because interrupter method production technique will experience the waiting process of the dischargings to be comminuted such as a few hours, molecule auto arrangement crystalline polamer can be there is at high operating temperatures in the material now reacting complete, the density proportion of vibrin product is caused to become large, the aspect defects such as the coating surface glossiness of the finished product powder coating lowers, the attenuating of spraying quadrature;

7) carry out in same reactor because the heating and cooling of batch process are many, will consume a large amount of time between each process section runs temperature reduction technology, causes the time unnecessary in a large number to wait for, affects production efficiency;

8) for meeting the demand of polyester to powder coating, reactor can only simply do larger and larger by interrupter method synthesizing polyester resin, even occurred once feeding intake the reactor of tens tons, equipment is larger also just mean the requirement of equipment itself and periphery support equipment higher, safety control measures requires also higher, the investment amount of equipment will exponentially formula increase, and increase production cost; Meanwhile, production unit increases technology controlling and process and the safety control difficulty of interrupter method after increasing, and accident relief difficulty is high.

Application number: disclose a kind of method that discarded polyethylene terephthalate recovery prepares polyester used for powder coating in 200610154611.7, this application have employed batch process, and without ethylene glycol separating technology in the method, ethylene glycol is caused to remain in system, cause final products obtained therefrom low at powder storage stability, powder coating gloss of film degree, levelling degree, the salt spray resistance of paint film, hydrolysis, uvioresistant intensity are low, powder coating is than great, spraying quadrature is little, of poor benefits; In addition because ethylene glycol is not separated, cause the use properties of powder coating to have above-mentioned limitation, usage ratio can not be high in the special saturated polyester resin of powder coating to cause regeneration to gather stupid dicarboxylic acid esters material, and economic benefit is low, without industrial application value.

Summary of the invention

Technical problem to be solved by this invention is: provide a kind of with the continuous processing production technique of polyethylene terephthalate (PET) uninterrupted charging and discharging for main raw material adopts, prepare the method for the special saturated polyester resin of thermosetting powder coating(s), this process stabilizing, energy consumption are low, with short production cycle, facility investment is few.

For solving the problems of the technologies described above, technical scheme of the present invention is: a kind of continuous processing prepares the method for polyester resin for powder coating, the steps include:

1) polyethylene terephthalate (PET) is added screw extrusion press continuously, controlling screw extrusion press temperature is 180 ~ 280 DEG C, extrude polyethylene terephthalate (PET) melt-stoichiometry (passing through melt metering pump) and add alcoholysis reaction still, in reactor, be metered into catalyzer and the boiling point dibasic alcohol higher than ethylene glycol simultaneously; Control reacting kettle inner pressure is 0.1MPa ~ 6MPa, temperature is 150 ~ 260 DEG C, and material total residence time is 0.5h ~ 6h;

Described polyethylene terephthalate and the mass ratio of dibasic alcohol are 1:0.5 ~ 3; Described alcoholysis catalysts accounts for 0.1 ‰ ~ 5 ‰ of polyethylene terephthalate quality;

Described dibasic alcohol is neopentyl glycol, methyl propanediol, Diethylene Glycol, 1,3-PD, BDO, special pentanediol or 1,4 cyclohexane dimethanol;

2) when the dibasic alcohol described in step 1) is neopentyl glycol, step 1) gained material is at the uniform velocity quantitatively added in knockout tower after 50 ~ 200 order filtering and impurity removings, import entrainer continuously simultaneously, controlling knockout tower internal pressure is normal pressure, temperature is 130 ~ 230 DEG C, control to be separated tower top temperature 90 ~ 150 DEG C, material fractionation by distillation in knockout tower stops 1 ~ 8h, and continuous and quantitative isolates the azeotrope (carrying out in quantizer) of entrainer and ethylene glycol simultaneously;

Described polyethylene terephthalate and the mass ratio of entrainer are 1:0.2 ~ 0.8; Reflux ratio 1:0.5 ~ 1:10 is controlled in described fractionation by distillation process;

When the dibasic alcohol described in step 1) is methyl propanediol, Diethylene Glycol, 1, ammediol, 1,4-butyleneglycol, special pentanediol or 1, during 4-cyclohexanedimethanol, step 1) gained material is at the uniform velocity quantitatively added in knockout tower after 50 ~ 200 order filtering and impurity removings, under normal pressure, controls temperature in knockout tower and be 130 ~ 240 DEG C, control to be separated tower top temperature 150 ~ 210 DEG C, material fractionation by distillation in knockout tower stops 1 ~ 8h, and continuous and quantitative isolates ethylene glycol;

Reflux ratio 1:0.5 ~ 1:10 is controlled in described fractionation by distillation process;

3) by step 2) process terminate after material be at the uniform velocity transferred to band water separation column reaction kettle of the esterification, add polyprotonic acid and/or corresponding acid anhydrides, polyvalent alcohol, stablizer, the catalyzer of polyprotonic acid simultaneously, under normal pressure, control esterification temperature in the kettle is 200 ~ 260 DEG C, reaction kettle of the esterification mixing speed is 20 ~ 60 revs/min, and material is at reaction kettle of the esterification lactonization reaction 0.5 ~ 5h;

In esterification reaction process, on-line period monitoring acid number and viscosity: when preparing product is epoxy/polyester mixed polyester resin used for powder coating, detection acid number is 10 ~ 40mgKOH/g, 150 DEG C of monitoring viscosities are 10 ~ 100cP, and esterification terminates; When preparing product is pure polyester resin used for powder coating (isocyanuric acid three-glycidyl ester (TGIC) solidification or beta-hydroxy alkylamide (HAA) curing polyester resin), monitoring acid number is 20 ~ 60mgKOH/g, 200 DEG C of monitoring viscosities are 0.5 ~ 30CP, and esterification terminates;

In described esterification reaction process, control to be separated the water that tower top temperature 95 ~ 105 DEG C isolates generation;

Described polyprotonic acid is selected from one or more in following substances: diprotic acid, triprotic acid, tetraprotic acid; Described diprotic acid and/or acid anhydrides corresponding to diprotic acid account for 15 ~ 40Wt.% of polyethylene terephthalate; Described triprotic acid and/or acid anhydrides corresponding to triprotic acid account for 1 ~ 10Wt.% of polyethylene terephthalate; Described tetraprotic acid and/or acid anhydrides corresponding to tetraprotic acid account for 0.5 ~ 3Wt.% of polyethylene terephthalate;

Described polyvalent alcohol is selected from one or more in following substances: dibasic alcohol, trivalent alcohol, tetravalent alcohol; Described dibasic alcohol accounts for 1 ~ 10Wt.% of polyethylene terephthalate; Described trivalent alcohol accounts for 1 ~ 5Wt.% of polyethylene terephthalate; Described tetravalent alcohol accounts for 0.5 ~ 3Wt.% of polyethylene terephthalate;

Described stablizer accounts for 0.05 ~ 0.5Wt.% of polyethylene terephthalate; Described esterifying catalyst accounts for 0.1 ~ 0.5Wt.% of polyethylene terephthalate;

4) by step 3) esterification technique section terminate after material be at the uniform velocity transferred in polymerization reaction kettle after 50 ~ 200 orders filter, control that polymerization reaction kettle internal pressure is 1000 ± 800Pa, temperature is 220 ~ 280 DEG C, polyreaction 0.5 ~ 5h;

On-line monitoring acid number and viscosity: when preparing product is mixed type curable epoxide vibrin used for powder coating, sampling detection acid number is 5 ~ 20mgKOH/g, 200 DEG C of monitoring viscosities are 5 ~ 50CP, and polyreaction terminates; When preparing product is pure polyester type vibrin used for powder coating (TGIC or HAA curing polyester resin), sampling detection acid number is 20 ~ 50mgKOH/g, 200 DEG C of monitoring viscosities are 10 ~ 100CP, and polyreaction terminates;

5) material after step 4) polyreaction being terminated is transferred in next reactor, simultaneous quantitative adds curing catalyst, under normal pressure, controlling temperature of reaction kettle is 180 ~ 230 DEG C, reactor mixing speed is 20 ~ 120 revs/min, stirs 0.5 ~ 2h, mixes, after filtration, extrude, cool, pulverize, obtain pure polyester type vibrin used for powder coating (isocyanuric acid three-glycidyl ester (TGIC) solidification or beta-hydroxy alkylamide (HAA) curing polyester resin);

Described curing catalyst is triphenyl ethyl phosphonium bromide phosphorus or triphenyl phosphorus; Described curing catalyst accounts for 0.1 ~ 10Wt.% of polyethylene terephthalate;

Or

Material after step 4) polyreaction being terminated is transferred in next reactor, quantitatively add trimellitic acid 1,2-anhydride by formula for a product requirement simultaneously, control temperature is 200 ~ 230 DEG C, react after 1 ~ 2 hour, cooling temperature of charge is 160 ~ 180 DEG C, add curing catalyst again, under normal pressure, reactor mixing speed is 20 ~ 120 revs/min, stir 0.5 ~ 2h, mix, after filtration, extrude, cool, pulverize (particulate state being less than 5mm) and obtain epoxy/polyester mixed type curable epoxide vibrin used for powder coating;

Described trimellitic acid 1,2-anhydride accounts for 5 ~ 30Wt.% of polyethylene terephthalate; Described curing catalyst is 1816 tertiary amines, and the curing catalyst stated accounts for 0.5 ~ 15Wt.% of polyethylene terephthalate.

Polyethylene terephthalate (PET) described in step 1) is the polyethylene terephthalate that regeneration is reclaimed, and wherein, the mass percentage of PET is greater than 90%.

The PET material raw material that described regeneration is reclaimed is selected from one or more in following substances: PET packing material, PET polyester material, the textile of polyester material, clothing material.

Described PET packing material is drink bottle sheet and/or film packaging sheet material; The polyester material of thread, block, paste, liquid, all kinds of polymerization degree that described polyester material produces for industry such as polyester chemistry polymerization chip, macrofiber, staple fibre etc.; The textile of described polyester material, clothing material are the cloth-like of PET polyester material, thread polyester material.

Step 1) and the catalyzer described in step 3) are: antimony system, germanium system, titanium system, tin series catalysts or the metal acetate salt except antimony, germanium, titanium, tin.

Described catalyzer is: antimonous oxide, antimony acetate, antimony glycol, tetrabutyl titanate, manganese acetate, zinc acetate, calcium acetate, Cobaltous diacetate.

Step 2) described in entrainer be: dimethylbenzene, toluene, ethylbenzene, normal hexane, hexanaphthene, own dioxane methyl alcohol or acetone;

Step 2) described in the azeotrope of entrainer and ethylene glycol be separated by phase splitter and obtain entrainer and ethylene glycol, glycol recovery, entrainer recycles, and phase splitter sepn process controls temperature of charge 5 ~ 30 DEG C.

Diprotic acid described in step 3) is selected from one or more in following substances: terephthalic acid, m-phthalic acid, phthalic acid, hexanodioic acid, pentanedioic acid, sebacic acid; Described triprotic acid is TMLA, and the acid anhydrides that described triprotic acid is corresponding is trimellitic acid 1,2-anhydride; The acid anhydrides that described tetraprotic acid is corresponding is pyromellitic dianhydride;

Dibasic alcohol described in step 3) is selected from one or more in following substances: neopentyl glycol, methyl propanediol, Diethylene Glycol, 1,3-PD, BDO, special pentanediol, 1,4 cyclohexane dimethanol; Described trivalent alcohol is selected from one or more in following substances: glycerol, TriMethylolPropane(TMP), trimethylolethane; Described tetravalent alcohol is tetramethylolmethane.

Stablizer described in step 3) is selected from one or more in following substances: phosphoric acid, phosphorous acid, phosphoric acid ester, phosphorous acid ester.

Continuous processing prepares the method for polyester resin for powder coating, and a kind of technical scheme is in addition: a kind of with terephthalic acid (PTA) for main raw material continuous processing prepares the method for special vibrin used for powder coating, the steps include:

A) by dibasic alcohol and/or trivalent alcohol, stablizer, catalyst mix making beating, be warmed up to 100 ± 10 DEG C, add terephthalic acid (PTA) again, be stirred to material dispersed in slurry form, join in reaction kettle of the esterification with constant speed by mixed slurry, controlling temperature of charge in esterifier is 240 ± 30 DEG C, carries out esterification under normal pressure, controlling tower top temperature is 100-105 DEG C of esterification water of discharging generation, and the total residence time of material in esterifier is 3 ± 0.5 hours;

Described dibasic alcohol and/or trivalent alcohol account for 65 ~ 85Wt.% of terephthalic acid, and stablizer accounts for 0.05 ~ 0.1Wt.% of terephthalic acid, and esterifying catalyst accounts for 0.1 ~ 0.2Wt.% of terephthalic acid;

One or more in following substances of described dibasic alcohol: neopentyl glycol, methyl propanediol, Diethylene Glycol, 1,3-PD, BDO, special pentanediol or 1,4 cyclohexane dimethanol;

Described trivalent alcohol is: glycerol and/or TriMethylolPropane(TMP);

Described stablizer is selected from one or more in following substances: phosphoric acid, phosphorous acid, phosphoric acid ester, phosphorous acid ester.

Described catalyzer is: antimony system, germanium system, titanium system, tin series catalysts or the metal acetate salt except antimony, germanium, titanium, tin;

B) step a) gained carboxylate constant speed is transferred to the second esterifier, add diprotic acid, stablizer to the second esterifier simultaneously, the temperature controlling the second esterifier is 240 ± 30 DEG C, under normal pressure, carry out esterification, control tower top temperature is 95-105 DEG C, and the total residence time of material in the second esterifier is 5 ± 0.5 hours;

Described diprotic acid accounts for 5 ~ 20Wt.% of terephthalic acid, described stablizer accounts for 0.05 ~ 0.1Wt.% of terephthalic acid

C) by step b) esterification technique section terminate after material be at the uniform velocity transferred in polymerization reaction kettle after 50 ~ 200 orders filter, control that batch condensation polymerization reactor internal pressure is 0.1KPa ~ 50KPa, temperature is 220 ~ 280 DEG C, polyreaction 0.5 ~ 6h;

On-line monitoring acid number and viscosity: when preparing product is epoxy/polyester mixed type curable epoxide vibrin used for powder coating, sampling detection acid number is 5 ~ 20mgKOH/g, 200 DEG C of monitoring viscosities are 5 ~ 50CP, and polyreaction terminates; When preparing product is pure polyester type vibrin used for powder coating (isocyanuric acid three-glycidyl ester (TGIC) solidification or beta-hydroxy alkylamide (HAA) curing polyester resin), sampling detection acid number is 20 ~ 50mgKOH/g, 200 DEG C of monitoring viscosities are 10 ~ 100CP, and polyreaction terminates;

D) material after step c) polycondensation being terminated is transferred in next reactor, quantitatively add curing catalyst by formula for a product requirement simultaneously, under normal pressure, controlling temperature of reaction kettle is 180 ~ 230 DEG C, reactor mixing speed is 20 ~ 120 revs/min, stir 0.5 ~ 2h, mix, after filtration, extrude, cool, pulverize and obtain pure polyester type vibrin used for powder coating (TGIC solidification or HAA curing polyester resin);

The curing catalyst stated is triphenyl ethyl phosphonium bromide phosphorus or triphenyl phosphorus; Described curing catalyst accounts for 0.1 ~ 0.3Wt.% of terephthalic acid;

Or

Material after step c) polyreaction being terminated is transferred in next reactor, quantitatively add trimellitic acid 1,2-anhydride by formula for a product requirement simultaneously, control temperature is 200 ~ 230 DEG C, react after 1 ~ 2 hour, cooling temperature of charge is 160 ~ 180 DEG C, add curing catalyst again, under normal pressure, reactor mixing speed is 20 ~ 120 revs/min, stir 0.5 ~ 2h, mix, after filtration, extrude, cool, be ground into the particulate state being less than 10mm and obtain epoxy/polyester mixed type curable epoxide vibrin used for powder coating;

Described trimellitic acid 1,2-anhydride accounts for 15 ~ 20Wt.% of terephthalic acid; Described curing catalyst is 1816 tertiary amines; Described curing catalyst accounts for 1 ~ 3Wt.% of terephthalic acid.

Beneficial effect of the present invention: the technological process that the invention discloses the terephthalic acid replacing conventional formulation main component with polyethylene terephthalate, also can use the polyethylene terephthalate through reclaiming, the present invention has the advantage of following two broad aspect with traditional batch method production technique on formulation cost and synthesis technique;

One, the advantage of continuous processing production technique:

1) by the means of the aspects such as automatization adjust flux, temperature, pressure, real-time Automated condtrol and on-line monitoring are carried out to each process section, constant product quality, with short production cycle; Reduce personnel's consumption simultaneously, reduce production cost;

2) each process section of whole production line the constant free of discontinuities of heat exchange mode, without waiting for material cooling time, be beneficial to heat energy recycling, save energy;

3) material is directly entering next reaction process after completion of the reaction, reduces and is detained, while energy-conservation, greatly reducing material side reaction and hyperreactive possibility;

4) compared with batch production, under same production capacity condition, greatly reduce the volumetric quantity of equipment, plant factor is high, equipment investment is low, achieves the compact of production unit, avoids the excessive risk process of reactor under 260 DEG C of conditions of high temperature during violent chemical reaction of tens tons, the controllability of production and safety is high, and safety precautions is more effective;

5) whole reaction process is all carried out in confined conditions, can machine automatization metering feed intake, online automatic detection, and prosthetic is uncapped and fed intake, samples, compensates the primitive operations such as material, improves the security of direct labor; In addition in production process without uncontrollable discharge gas, be conducive to environment protection;

6) specific duty consuming time low, consume energy little; Because waiting for without cooling stage, sharply be cooled to again 180 DEG C without the need to using 260 DEG C of high temperature on the same device and be heated to extreme processing requirement such as 260 DEG C of grades more as early as possible, decrease the violent harmomegathus distortion hidden danger of equipment, while proterctive equipment, turn improve equipment operating safety degree;

7) wait for without the need to discharging in reactor after material reaction, stopped the volatilization of material curing catalyst in high temperature etc. bides one's time generation side reaction and formula, quality product is stablized more, reduces environmental pollution;

8) products obtained therefrom narrow molecular weight distribution, after polyester product is applied to powder coating, the solidification fastness of powder coating and the ageing-resistant performance of paint film better.

Two, the advantage that regeneration polyethylene terephthalate (PET) is main raw material is used:

1) achieve resource recovery saving and protectiveness utilization, be conducive to protection of the environment and reduce the unnecessary wasting of resources;

2) use polyethylene terephthalate (PET) transesterification reaction, absorb heat in a large number without the need to esterification, save energy, produce without the esterification waste water that COD is high while reclaiming ethylene glycol, environment protection and economic benefit have many advantages.

Accompanying drawing explanation

Fig. 1 utilizes PET and neopentyl glycol to prepare the process flow sheet of thermoset saturated polyester resin used for powder coating for starting raw material continuous processing;

Fig. 2 utilizes PET with the dibasic alcohol except neopentyl glycol for starting raw material continuous processing prepares the process flow sheet of thermoset saturated polyester resin used for powder coating.

Fig. 3 utilizes PTA and polyvalent alcohol to prepare the process flow sheet of thermoset saturated polyester resin used for powder coating for starting raw material continuous processing.

Embodiment

According to main use approach and the variety classification of thermosetting powder coating(s); select the synthesizing formula (just for a checking to end product quality characteristic of the present invention, any use of the change on this formula does not affect protection of the present invention to this formula) of more common each model vibrin:

In table 1 embodiment 1 to embodiment 7, material composition in process prepared by vibrin:

Embodiment 1

Pilot scale (10KG/ hour) device, the special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) that continuous process terephthalic acid (PTA) synthesizes, acid number 72 ± 5mgKOH/g viscosity 22 ± 5cSt(200 DEG C) softening temperature 105 ± 5 DEG C.

The neopentyl glycol of the 87.43KG of embodiment 1 recipe requirements is dropped into respectively in the PTA slurry preparation still be used alternatingly by 2, 12.21KG Diethylene Glycol, 1.17KG TriMethylolPropane(TMP), the triphenyl phosphite of 0.092KG, 0.207KG Mono-n-butyltin, start and be stirred to 40 revs/min, be warmed up to 100 DEG C, get rid of moisture, add the terephthalic acid (PTA) of 137.25KG, thoroughly be stirred to material homodisperse in slurry form, open the discharge port valve of a slurry kettle, join in reaction kettle of the esterification by mashing pump with the constant airspeed of 9.875KG/ hour, in esterifier, mother liquor temperature is set in 250 DEG C, normal pressure, stir as down-push type, blade rotating speed is 80 revs/min, material injects along position on stir shaft, fresh material is pushed reactor bottom by agitating vane fast, material is moved along the heat absorption of reactor still wall, complete esterification fast, the esterification water produced is discharged through the knockout tower tower top be connected with esterifier, setting tower top temperature is 100-105 DEG C, the speed that esterification water is discharged is 1.24KG/ hour, the total residence time of material in esterifier is 3 hours, after completion of the reaction material under the water conservancy diversion of still inner deflector along still wall automatic stream esterifier discharge port, on-line monitoring carboxylate is 8.634KG/ hour from the speed that esterifier flows out, monitoring carboxylate injects the second esterifier with the constant speed of 8.634KG/ hour, add the hexanodioic acid of recipe requirements to the second esterifier by the constant speed of 0.437KG/ hour, the temperature of the second esterifier is set in 250 DEG C, pressure is normal pressure, stir as down-push type blade rotating speed is 80 revs/min, hexanodioic acid 10.49KG/ hour, within triphenyl phosphite 0.09KG/ hour, two materials inject from reactor center position simultaneously, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, esterification is completed in abundant heat exchange, the water that esterification is released is discharged through knockout tower tower top, setting tower top temperature is 95-105 DEG C, the speed that esterification water is discharged is 0.111KG/ hour, the total residence time of material in the second esterifier is 5 hours, material flows to esterifier discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, on-line monitoring carboxylate is 8.96KG/ hour from the speed that esterifier flows out, the acid number of outlet on-line monitoring material is 25 ± 5mgKOH/g, viscosity is 20 ± 5cSt(150 DEG C).

The complete material of esterification is under the control of melt metering pump, with the constant rate of 8.96KG/ hour, inject from the feed end entrance of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 800pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump, the complete material of polymerization is extruded horizontal polymerization reactor under the condition overcoming vacuum state, the discharge of polymer melt is about 8.93KG/ hour, the acid number of on-line monitoring polymkeric substance is 10 ± 5mgKOH/g, viscosity is 16 ± 8cSt(200 DEG C).

Be polymerized complete material and inject next adjustment reactor with the constant speed of 8.93KG/ hour by Melt Pump, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of trimellitic acid 1,2-anhydride is 1.02KG/ hour, material is 1.5 hours in the total residence time of adjustment still, the acid number that material outlet place on-line checkingi obtains material is 72 ± 5mgKOH/g, and viscosity is 22 ± 5cSt(200 DEG C).Material is at the uniform velocity injected the second adjustment still with the speed of 9.95KG/ hour, the speed that adds of 1816 tertiary amines is 0.058KG/ hour, in second adjustment still, setting temperature of charge is 180 DEG C, mixing speed is 80 revs/min, through insulation Melt Pump, the material be fully uniformly mixed with 1816 tertiary amines is pumped into steel belt cooler with the speed of 10.01KG/ hour, cool in the form of sheets, be broken into the platy shaped particle of 10 ± 5mm square, obtain the special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) (throughput of about 10KG/ hour).

Embodiment 2

Pilot scale (10KG/ hour) device, the special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) that continuous process polyethylene terephthalate (PET) synthesizes, acid number is 72 ± 5mgKOH/g, viscosity is 21 ± 5cSt(200 DEG C), softening temperature is 104 ± 5 DEG C.

By the polyethylene terephthalate (PET) of clean dried through Screw Extrusion, the elementary warm area of screw rod design temperature is 240 DEG C, middle rank warm area 265 DEG C, final high temperature level district is 280 DEG C, by through Screw Extrusion polyethylene terephthalate (PET) melt according to constant be that the speed of 5.916KG/ hour injects alcoholysis reaction still, simultaneously also by prior by quality be 1.388/1000 zinc acetate/neopentyl glycol mixing solutions inject alcoholysis reaction still by the constant speed of 4.148KG/ hour, alcoholysis reaction still material design temperature is 220 DEG C, setting pressure is 2 ± 0.5Mpa, press-down type agitating vane, mixing speed is 80 revs/min, polyethylene terephthalate (PET) melt material and zinc acetate/neopentyl glycol solution inject from position agitating vane, the material such as melt and neopentyl glycol pushes bottom alcoholysis reaction still by agitating vane fast, make material along alcoholysis reaction still wall heat exchange campaign, material completes alcoholysis and transesterification reaction fast, the total residence time of material in alcoholysis reaction device is 3 hours, material flows to alcoholysis reaction device discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, alcoholysis reaction device is pumped via Melt Pump, on-line monitoring alcoholysate is 10.064KG/ hour from the speed that alcoholysis reaction device flows out,

Monitoring alcoholysate injects xylenes ethylene glycol knockout tower top with the constant speed of 10.064KG/ hour, be incubated at 170 ± 20 DEG C in the middle part of tower body, tower bottom establishes dimethylbenzene generator, the dimethylbenzene gas being heated to seethe with excitement injects from tower bottom with the speed of 2.958KG/ hour, gas phase dimethylbenzene fully contacts in knockout tower with alcoholysate, control tower top temperature at 140 ± 20 DEG C, the flow of the dimethylbenzene that tower top slips out and ethylene glycol azeotrope is 4.87KG/ hour, dimethylbenzene ethylene glycol azeotrope is cooled to less than 10 DEG C, the dimethylbenzene of top section and the ethylene glycol of underclad portion is isolated in phase splitter, dimethylbenzene upper strata condensation obtained re-injected into 2.958KG/ hour the azeotropic again participating in ethylene glycol in dimethylbenzene generator and carries secretly, namely phase splitter underclad portion ethylene glycol can be used as byproduct and reclaim, the speed reclaimed is 1.912KG/ hour.

Liquid phase alcoholysate through with gas phase dimethylbenzene fully contact remove ethylene glycol after flowed out by tower bottom, the speed that carboxylate at the bottom of tower flows out is 8.15KG/ hour, the ethylene glycol residual quantity of on-line monitoring carboxylate is less than 0.3%, material injects esterifier with the constant speed of 8.15KG/ hour, press recipe requirements by hexanodioic acid 0.946KG/ hour simultaneously, the mixed solution of triphenyl phosphite/TriMethylolPropane(TMP)=7.86/100 adds to esterifier with the constant speed of 0.0526KG/ hour, the temperature of esterifier is set in 250 DEG C, normal pressure, stir as down-push type blade, rotating speed is 80 revs/min, material injects from reactor center position, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, abundant heat exchange completes esterification, the water that esterification is released is discharged through knockout tower tower top, setting tower top temperature is 95-105 DEG C, the speed that esterification water is discharged is 0.239KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still lactone compound flow deflector along still wall automatic stream discharge port, on-line monitoring carboxylate is 8.909KG/ hour from the speed that esterifier flows out, the acid number that outlet on-line monitoring obtains material is 25 ± 5mgKOH/g, viscosity is 19 ± 5cSt(150 DEG C).

Under the control of the complete material of esterification at melt metering pump, with the constant rate of 8.909KG/ hour, be injected into the feed end of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 800pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump by material extrusion reaction device complete for polymerization, the discharge of polymer melt is about 8.9KG/ hour, 10 ± 5mgKOH/g of on-line monitoring polymkeric substance, viscosity is 15 ± 8cSt(200 DEG C).

Be polymerized complete material and inject next adjustment reactor with the constant speed of 8.9KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of trimellitic acid 1,2-anhydride is 1.02KG/ hour, material is 1.5 hours in the total residence time of adjustment still, and the acid number that material outlet place on-line checkingi obtains material is 72 ± 5mgKOH/g, viscosity is 21 ± 5cSt(200 DEG C), softening temperature is 104 ± 5 DEG C.Material is at the uniform velocity injected the second adjustment still with the speed of 9.92KG/ hour, the speed that adds of 1816 tertiary amines is 0.058KG/ hour, in second adjustment still, setting temperature of charge is 180 DEG C, mixing speed is 80 revs/min, through insulation Melt Pump, the material be fully uniformly mixed with 1816 tertiary amines is pumped into steel belt cooler with the speed of 9.978KG/ hour, cool in the form of sheets, be broken into the platy shaped particle of 10 ± 5mm square, the i.e. special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) (throughput of about 10KG/ hour) that synthesizes of handy polyethylene terephthalate (PET).

Embodiment 3

Large examination (605KG/ hour, 5000 tons/year) device, the special epoxy/polyester mixed polyester resin of epoxy/polyester=4/6 thermosetting powder coating(s) of continuous process polyethylene terephthalate synthesis, acid number is 55 ± 5mgKOH/g, viscosity is 23 ± 5cSt(200 DEG C), softening temperature is 105 ± 5 DEG C.

By the polyethylene terephthalate (PET) of clean dried through Screw Extrusion, the elementary warm area of screw rod design temperature is 240 DEG C, middle rank warm area 265 DEG C, final high temperature level district is 280 DEG C, by through Screw Extrusion polyethylene terephthalate (PET) melt according to constant be that the speed of 375.69KG/ hour injects alcoholysis reaction still, simultaneously also just prior by quality be 1.388/1000 zinc acetate/neopentyl glycol solution inject alcoholysis reaction still by the constant speed of 263.36KG/ hour, alcoholysis reaction still material design temperature is 220 DEG C, setting pressure is 2 ± 0.5Mpa, press-down type agitating vane, mixing speed is 80 revs/min, polyethylene terephthalate (PET) melt material and zinc acetate/neopentyl glycol solution inject from position agitating vane, the material such as melt and neopentyl glycol pushes bottom alcoholysis reaction still by agitating vane fast, material is moved along alcoholysis reaction still wall, material completes alcoholysis and transesterification reaction fast, the total residence time of material in alcoholysis reaction device is 3 hours, material flows to alcoholysis reaction device discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, alcoholysis reaction device is pumped via Melt Pump, on-line monitoring alcoholysate is 639.057KG/ hour from the speed that alcoholysis reaction device flows out.

Alcoholysate is injected xylenes ethylene glycol knockout tower top with the constant speed of 639.057KG/ hour, be incubated in the middle part of whole tower body at 170 ± 20 DEG C, tower bottom establishes dimethylbenzene generator, xylene steam is injected from tower bottom with the speed of 187.845KG/ hour, gas phase dimethylbenzene fully contacts in knockout tower with alcoholysate, control tower top temperature at 140 ± 20 DEG C, the flow of the dimethylbenzene that tower top slips out and ethylene glycol azeotrope is 328.32KG/ hour, dimethylbenzene ethylene glycol azeotrope is cooled to less than 10 DEG C, the dimethylbenzene of top section and the ethylene glycol of underclad portion is isolated in phase splitter, dimethylbenzene upper strata condensation obtained refilled with 187.845KG/ hour the azeotropic again participating in ethylene glycol in dimethylbenzene generator and carries secretly, namely the isolated ethylene glycol of phase splitter lower layer part can be used as byproduct and reclaim, the speed reclaimed is 140.48KG/ hour.Liquid phase alcoholysate through with gas phase dimethylbenzene fully contact remove ethylene glycol after flowed out by tower bottom, at the bottom of tower carboxylate flow out speed be 498.58KG/ hour.

The ethylene glycol residual quantity of on-line monitoring carboxylate is less than 0.3%, material injects esterifier with the constant speed of 498.58KG/ hour, press recipe requirements by hexanodioic acid 63.66KG/ hour simultaneously, the mixed solution of triphenyl phosphite/TriMethylolPropane(TMP)=7.86/100 adds to esterifier with the constant speed of 3.336KG/ hour, the temperature of esterifier is set in 240 ± 20 DEG C, pressure is normal pressure, stir as down-push type blade, rotating speed is 80 revs/min, material injects from reactor center position, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, esterification is completed in abundant heat exchange, the water that esterification is released is discharged through the esterification water knockout tower tower top be connected with esterifier, setting tower top temperature is 98-105 DEG C, the speed that esterification water is discharged is 16.14KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still inner deflector along still wall automatic stream discharge port, on-line monitoring carboxylate is 549.44KG/ hour from the speed that esterifier flows out, outlet on-line monitoring obtains acid number 25 ± 5mgKOH/g viscosity 19 ± 5cSt(150 DEG C of material)

Under the control of the complete esterification of esterification at melt metering pump, with the constant rate of 549.44KG/ hour, be injected into the feed end entrance of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 800pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump, the complete material of polymerization is extruded horizontal polymerization reactor, the discharge of polymer melt is about 549KG/ hour, 8 ± 5mgKOH/g of on-line monitoring polymkeric substance, viscosity is 18 ± 8cSt(200 DEG C).

Be polymerized complete material and inject next adjustment reactor with the constant speed of 549KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of trimellitic acid 1,2-anhydride is 51.82KG/ hour, material is 1.5 hours in the total residence time of adjustment still, and material outlet place on-line checkingi obtains material acid number 55 ± 5mgKOH/g viscosity 23 ± 5cSt(200 DEG C) softening temperature 105 ± 5 DEG C.

Material is at the uniform velocity injected the second adjustment still with the speed of 601.26KG/ hour, the speed that adds of 1816 tertiary amines is 3.71KG/ hour, in second adjustment still, setting temperature of charge is 180 DEG C, mixing speed is 80 revs/min, through insulation Melt Pump, the material be fully uniformly mixed with 1816 tertiary amines is pumped into steel belt cooler with the speed of 604.96KG/ hour, cool in the form of sheets, be broken into the platy shaped particle of 10 ± 5mm square, the i.e. special epoxy/polyester mixed polyester resin of epoxy/polyester=4/6 thermosetting powder coating(s) (throughput of about 605KG/ hour) that synthesizes of handy polyethylene terephthalate (PET).

Embodiment 4

Pilot scale (10KG/ hour) device, the special pure polyester type vibrin of the polyester that continuous process terephthalic acid (PTA) synthesizes/TGIC=93/7 thermosetting powder coating(s), acid number 33 ± 5mgKOH/g viscosity 35 ± 10cSt(200 DEG C) softening temperature 108 ± 5 DEG C.

The neopentyl glycol of the 104.43KG of embodiment 1 recipe requirements is dropped into respectively in the PTA slurry preparation still be used alternatingly by 2, the triphenyl phosphite of 0.24KG, 0.228KG Mono-n-butyltin, start and be stirred to 40 revs/min, be warmed up to 100 DEG C, get rid of the moisture of trace, add the terephthalic acid (PTA) of 144.89KG, thoroughly be stirred to material homodisperse in slurry form, open the discharge port valve of a slurry kettle, join in reaction kettle of the esterification by mashing pump with the constant airspeed of 10.4083KG/ hour, in esterifier, mother liquor temperature is set in 250 DEG C, normal pressure, stir as down-push type blade rotating speed is 80 revs/min, material injects from reactor center position, fresh material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, complete esterification fast, the water that esterification is released is discharged through the esterification water knockout tower tower top be connected with esterifier, setting tower top temperature is 100-105 DEG C, the speed that esterification water is discharged is 1.309KG/ hour, the total residence time of material in esterifier is 3 hours, material flows to esterifier discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, on-line monitoring carboxylate is 9.099KG/ hour from the speed that esterifier flows out.

Monitoring carboxylate injects the second esterifier with the constant speed of 9.099KG/ hour, add these two kinds of materials of recipe requirements to the second esterifier by the constant speed of 1.0419KG/ hour m-phthalic acid and 0.0995KG/ hour hexanodioic acid, the temperature of the second esterifier is set in 250 DEG C, pressure is normal pressure, stir as down-push type blade rotating speed is 80 revs/min, material injects from reactor center position, the water that esterification is released is discharged through water separation column tower top, setting tower top temperature is 98-105 DEG C, the speed that esterification water is discharged is 0.25KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still inner deflector along still wall automatic stream esterifier discharge port, on-line monitoring carboxylate is 9.9904KG/ hour from the speed that esterifier flows out.

The complete material of esterification is under the control of melt metering pump, with the constant rate of 9.9904KG/ hour, be injected into the feed end entrance of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 900pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump, the complete material of polymerization is extruded horizontal polymerization reactor, the discharge of polymer melt is about 9.98KG/ hour, the acid number of on-line monitoring polymkeric substance is 33 ± 5mgKOH/g, viscosity is 35 ± 10cSt(200 DEG C), softening temperature is 108 ± 5 DEG C.

Be polymerized complete material and inject next adjustment reactor with the constant speed of 9.98KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, and the speed that adds of curing catalyst is 0.01KG/ hour, and material is 1.5 hours in the total residence time of adjustment still.The material be fully uniformly mixed with curing catalyst is pumped into steel belt cooler with the speed of 9.99KG/ hour through insulation Melt Pump by material, cool in the form of sheets, be broken into the platy shaped particle of 6mm square, namely obtain the special pure polyester type vibrin of polyester/TGIC=93/7 thermosetting powder coating(s) of terephthalic acid (PTA) continuous process synthesis.

Embodiment 5

Large examination (605KG/ hour, 5000 tons/year) device, the pure polyester type vibrin of thermosetting powder coating(s) dedicated polyester/TGIC=93/7 that continuous process polyethylene terephthalate (PET) synthesizes, acid number is 33 ± 5mgKOH/g, viscosity is 34 ± 10cSt(200 DEG C), softening temperature is 107 ± 5 DEG C.

By the polyethylene terephthalate (PET) of clean dried through Screw Extrusion, the elementary warm area of screw rod design temperature is 240 DEG C, middle rank warm area 265 DEG C, final high temperature level district is 280 DEG C, by through Screw Extrusion polyethylene terephthalate (PET) melt according to constant be that the speed of 387.85KG/ hour injects alcoholysis reaction still, simultaneously also by prior by quality be 1.388/1000 zinc acetate/neopentyl glycol solution inject alcoholysis reaction still by the constant speed of 263.56KG/ hour, alcoholysis reaction still material design temperature is 220 DEG C, setting pressure is 2 ± 0.5Mpa, press-down type agitating vane, mixing speed is 80 revs/min, polyethylene terephthalate (PET) melt material and zinc acetate/neopentyl glycol solution inject from position agitating vane, the material such as melt and neopentyl glycol pushes bottom alcoholysis reaction still by agitating vane fast, make material along alcoholysis reaction still wall heat exchange campaign, material completes alcoholysis and transesterification reaction fast, the total residence time of material in alcoholysis reaction device is 3 hours, material flows to alcoholysis reaction device discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, alcoholysis reaction device is pumped via Melt Pump, on-line monitoring alcoholysate is 651.38KG/ hour from the speed that alcoholysis reaction device flows out, temperature of charge is 190 DEG C.

Alcoholysis terminates rear material and injects xylenes ethylene glycol knockout tower top with the constant speed of 651.38KG/ hour, be incubated in the middle part of whole tower body at 180 DEG C, tower bottom establishes dimethylbenzene generator, dimethylbenzene gas injects from tower bottom with the speed of 193.91KG/ hour, gas phase dimethylbenzene fully contacts in knockout tower with alcoholysate, control tower top temperature at 140 ± 20 DEG C, the flow of the dimethylbenzene that tower top slips out and ethylene glycol azeotrope is 319.28KG/ hour, dimethylbenzene ethylene glycol azeotrope is cooled to less than 10 DEG C, the dimethylbenzene of top section and the ethylene glycol of underclad portion is isolated in phase splitter, dimethylbenzene upper strata condensation obtained re-injected into 193.91KG/ hour the azeotropic again participating in ethylene glycol in dimethylbenzene generator and carries secretly, namely phase splitter underclad portion ethylene glycol can be used as byproduct and reclaim, the speed reclaimed is 125.37KG/ hour.Liquid phase alcoholysate through with gas phase dimethylbenzene fully contact remove ethylene glycol after flowed out by tower bottom, at the bottom of tower carboxylate flow out speed be 526.01KG/ hour.

The ethylene glycol residual quantity of on-line monitoring carboxylate is less than 0.3%, material injects esterifier with the constant speed of 526.01KG/ hour, press recipe requirements by hexanodioic acid 6.02KG/ hour simultaneously, triphenyl phosphite 0.61KG/ hour, the constant speed of m-phthalic acid 93.04KG/ hour adds to esterifier, the temperature of esterifier is set in 250 DEG C, stir as down-push type blade, rotating speed is 80 revs/min, material injects from reactor center position, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, abundant heat exchange completes esterification, the water that esterification is released is discharged through knockout tower tower top, setting tower top temperature is 98-105 DEG C, the speed that esterification water is discharged is 21.7KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still inner deflector along still wall automatic stream esterifier discharge port, on-line monitoring carboxylate is 603.98KG/ hour from the speed that esterifier flows out.

Under the control of the complete material of esterification at melt metering pump, with the constant rate of 603.98KG/ hour, be injected into the feed end entrance of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 900pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, make the efficiency of polyreaction higher, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump, the complete material of polymerization is extruded horizontal polymerization reactor under the condition overcoming vacuum state, the discharge of polymer melt is about 603KG/ hour, the acid number of on-line monitoring polymkeric substance is 33 ± 5mgKOH/g, viscosity is 34 ± 10cSt(200 DEG C), softening temperature is 107 ± 5 DEG C.

Be polymerized complete material and inject next adjustment reactor with the constant speed of 603KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of curing catalyst is 0.605KG/ hour, abundant stirring, material is 1.5 hours in the total residence time of adjustment still.The material be fully uniformly mixed with curing catalyst is pumped into steel belt cooler with the speed of 603.605KG/ hour through insulation Melt Pump by material, cool in the form of sheets, be broken into the platy shaped particle that 10 ± 5mm is square, namely obtain the pure polyester type vibrin of thermosetting powder coating(s) dedicated polyester/TGIC=93/7 of continuous process polyethylene terephthalate synthesis.

Embodiment 6

Large examination (605KG/ hour, 5000 tons/year) device, the pure polyester type vibrin of thermosetting powder coating(s) polyester/T105=96/4 that continuous process polyethylene terephthalate (PET) synthesizes, acid number is 25 ± 5mgKOH/g, viscosity is 40 ± 15cSt(200 DEG C), softening temperature is 109 ± 5 DEG C.

By the polyethylene terephthalate (PET) of clean dried through Screw Extrusion, the elementary warm area of screw rod design temperature is 240 DEG C, middle rank warm area 265 DEG C, final high temperature level district is 280 DEG C, by through Screw Extrusion polyethylene terephthalate (PET) melt according to constant be that the speed of 385.35KG/ hour injects alcoholysis reaction still, simultaneously also by prior by quality be 1.388/1000 zinc acetate/neopentyl glycol solution inject alcoholysis reaction still by the constant speed of 267.61KG/ hour, alcoholysis reaction still material design temperature is 220 DEG C, setting pressure is 2 ± 0.5Mpa, press-down type agitating vane, mixing speed is 80 revs/min, polyethylene terephthalate (PET) melt material and zinc acetate/neopentyl glycol solution inject from position agitating vane, the material such as melt and neopentyl glycol pushes bottom alcoholysis reaction still by agitating vane fast, material is moved along alcoholysis reaction still wall, material completes alcoholysis and transesterification reaction fast, the total residence time of material in alcoholysis reaction device is 3 hours, material flows to alcoholysis reaction device discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, alcoholysis reaction device is pumped via Melt Pump, on-line monitoring alcoholysate is 652.96KG/ hour from the speed that alcoholysis reaction device flows out.

Monitoring alcoholysate injects xylenes ethylene glycol knockout tower top with the constant speed of 652.96KG/ hour, be incubated in the middle part of whole tower body at 180 ± 20 DEG C, tower bottom establishes dimethylbenzene generator, dimethylbenzene gas injects from tower bottom with the speed of 192.67KG/ hour, gas phase dimethylbenzene fully contacts in knockout tower with alcoholysate, control tower top temperature at 140 ± 20 DEG C, the flow of the dimethylbenzene that tower top slips out and ethylene glycol azeotrope is 317.25KG/ hour, dimethylbenzene ethylene glycol azeotrope is cooled to less than 15 ± 10 DEG C, the dimethylbenzene of top section and the ethylene glycol of underclad portion is isolated in phase splitter, dimethylbenzene upper strata condensation obtained re-injected into 192.67KG/ hour the azeotropic again participating in ethylene glycol in dimethylbenzene generator and carries secretly, namely phase splitter underclad portion ethylene glycol can be used as byproduct and reclaim, the speed reclaimed is 124.58KG/ hour.Liquid phase alcoholysate through with gas phase dimethylbenzene fully contact remove ethylene glycol after flowed out by tower bottom, at the bottom of tower carboxylate flow out speed be 528.37KG/ hour.

The ethylene glycol residual quantity of on-line monitoring carboxylate is less than 0.3%, material injects esterifier with the constant speed of 528.37KG/ hour, press recipe requirements by hexanodioic acid 6.11KG/ hour simultaneously, triphenyl phosphite 0.614KG/ hour, the constant speed of m-phthalic acid 94.47KG/ hour adds to esterifier, the temperature of esterifier is set in 250 DEG C, normal pressure, stir as down-push type blade, rotating speed is 80 revs/min, material injects from reactor center position, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, abundant heat exchange completes esterification, the water that esterification is released is discharged through knockout tower tower top, setting tower top temperature is 98-105 DEG C, the speed that esterification water is discharged is 22.04KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still inner deflector along still wall automatic stream esterifier discharge port, on-line monitoring carboxylate is 607.52KG/ hour from the speed that esterifier flows out.

Under the control of the complete esterification of esterification at melt metering pump, with the constant rate of 607.52KG/ hour, be injected into the feed end entrance of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 900pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, make the efficiency of polyreaction higher, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump, the complete material of polymerization is extruded horizontal polymerization reactor under the condition overcoming vacuum state, the discharge of polymer melt is about 607KG/ hour, the acid number of on-line monitoring polymkeric substance is 25 ± 5mgKOH/g, viscosity is 40 ± 15cSt(200 DEG C), softening temperature is 109 ± 5 DEG C.

Be polymerized complete material and inject next adjustment reactor with the constant speed of 607KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of curing catalyst is 0.614KG/ hour, abundant stirring, material is 1.5 hours in the total residence time of adjustment still.The material be fully uniformly mixed with curing catalyst is pumped into steel belt cooler with the speed of 607.614KG/ hour through insulation Melt Pump by material, cool in the form of sheets, be broken into the platy shaped particle of 10 ± 5mm square, namely obtain the pure polyester type vibrin of thermosetting powder coating(s) polyester/T105=96/4 of continuous process polyethylene terephthalate synthesis.

Embodiment 7

Pilot scale (10KG/ hour) device, the special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) that continuous process polyethylene terephthalate (PET) synthesizes, acid number is 72 ± 5mgKOH/g, viscosity is 19 ± 5cSt(200 DEG C), softening temperature is 102 ± 5 DEG C.

By the polyethylene terephthalate (PET) of clean dried through Screw Extrusion, the elementary warm area of screw rod design temperature is 240 DEG C, middle rank warm area 265 DEG C, final high temperature level district is 280 DEG C, by through Screw Extrusion polyethylene terephthalate (PET) melt according to constant be that the speed of 5.916KG/ hour injects alcoholysis reaction still, simultaneously also by prior by quality be 1.059/1000 cobaltous acetate/methyl propanediol mixing solutions inject alcoholysis reaction still by the constant speed of 3.59KG/ hour, alcoholysis reaction still material design temperature is 220 DEG C, setting pressure is 2 ± 0.5Mpa, press-down type agitating vane, mixing speed is 80 revs/min, polyethylene terephthalate (PET) melt material and zinc acetate/neopentyl glycol solution inject from position agitating vane, the material such as melt and neopentyl glycol pushes bottom alcoholysis reaction still by agitating vane fast, material is moved along alcoholysis reaction still wall, material completes alcoholysis and transesterification reaction fast, the total residence time of material in alcoholysis reaction device is 3 hours, material flows to alcoholysis reaction device discharge port along still wall under the water conservancy diversion of still inner deflector after completion of the reaction, alcoholysis reaction device is pumped via Melt Pump, on-line monitoring alcoholysate is 9.506KG/ hour from the speed that alcoholysis reaction device flows out,

Monitoring alcoholysate injects in the middle part of ethylene glycol knockout tower with the constant speed of 9.506KG/ hour, whole tower body insulation is at 180 ± 20 DEG C, alcoholysate fully contacts filler in knockout tower, control tower top temperature at 196 ~ 200 DEG C, the ethylene glycol flow that tower top slips out is 1.912KG/ hour, and namely ethylene glycol can be used as byproduct and reclaim.

Liquid phase alcoholysate through with gas phase dimethylbenzene fully contact remove ethylene glycol after flowed out by tower bottom, the speed that carboxylate at the bottom of tower flows out is 7.594KG/ hour, the ethylene glycol residual quantity of on-line monitoring carboxylate is less than 0.1%, material injects esterifier with the constant speed of 7.594KG/ hour, press recipe requirements by hexanodioic acid 0.946KG/ hour simultaneously, the mixed solution of triphenyl phosphite/TriMethylolPropane(TMP)=7.86/100 adds to esterifier with the constant speed of 0.0526KG/ hour, the temperature of esterifier is set in 250 DEG C, normal pressure, stir as down-push type blade, rotating speed is 80 revs/min, material injects from reactor center position, material is pushed reactor bottom by agitating vane fast, material is moved along reactor still wall, abundant heat exchange completes esterification, the water that esterification is released is discharged through knockout tower tower top, setting tower top temperature is 95-105 DEG C, the speed that esterification water is discharged is 0.239KG/ hour, the total residence time of material in esterifier is 5 hours, after completion of the reaction material under the water conservancy diversion of still lactone compound flow deflector along still wall automatic stream discharge port, on-line monitoring carboxylate is 8.353KG/ hour from the speed that esterifier flows out, the acid number that outlet on-line monitoring obtains material is 25 ± 5mgKOH/g, viscosity is 17 ± 5cSt(150 DEG C).

Under the control of the complete material of esterification at melt metering pump, with the constant rate of 8.353KG/ hour, be injected into the feed end of horizontal polymerization reactor, the temperature of charge of horizontal polymerization reactor is set in 245 DEG C, vacuum tightness is 1000 ± 800pa, establish cage agitator that the surface of carboxylate is strengthened in horizontal polymerization reactor, thinning and upgrade as early as possible, be conducive to free micromolecular diffusion and overflow as early as possible, material progressively flows to discharge port end along specific direction from feed inlet end in horizontal polymerization reactor, the total residence time of material in horizontal polymerization reactor is 3 hours, discharge port is established bottom the other end of horizontal polymerization reactor, by online Melt Pump by material extrusion reaction device complete for polymerization, the discharge of polymer melt is about 8.3KG/ hour, 10 ± 5mgKOH/g of on-line monitoring polymkeric substance, viscosity is 13 ± 8cSt(200 DEG C).

Be polymerized complete material and inject next adjustment reactor with the constant speed of 8.3KG/ hour by Melt Pump, in still, setting temperature of charge is 200 DEG C, mixing speed is 80 revs/min, the speed that adds of trimellitic acid 1,2-anhydride is 1.02KG/ hour, material is 1.5 hours in the total residence time of adjustment still, and the acid number that material outlet place on-line checkingi obtains material is 72 ± 5mgKOH/g, viscosity is 19 ± 5cSt(200 DEG C), softening temperature is 102 ± 5 DEG C.Material is at the uniform velocity injected the second adjustment still with the speed of 9.37KG/ hour, the speed that adds of 1816 tertiary amines is 0.058KG/ hour, in second adjustment still, setting temperature of charge is 180 DEG C, mixing speed is 80 revs/min, through insulation Melt Pump, the material be fully uniformly mixed with 1816 tertiary amines is pumped into steel belt cooler with the speed of 9.43KG/ hour, cool in the form of sheets, be broken into the platy shaped particle of about 10mm square, the i.e. special epoxy/polyester mixed polyester resin of epoxy/polyester=5/5 thermosetting powder coating(s) (throughput of about 10KG/ hour) that synthesizes of handy polyethylene terephthalate (PET).

Table 1: the special saturated polyester resin product performance of powder coating in embodiment 1 to embodiment 7:

With regard to the different performance of 7 special saturated polyester resins of powder coating that technical solution of the present invention obtains, by selecting corresponding more representative powder coating formulation (table 2), the mixing powder coating making 7 kinds of corresponding kinds, spray test uses, and its performance embodies following (table 3);

The vibrin of table 2 embodiment synthesis adopt following powder coating formulation (unit: g):

Mixed in mixing machine by above premixture, melt extruded by diameter 30 twin screw extruder, the extrudate of cooling carries out pulverizing and 200 orders sieve and obtain powder coating.

Adopt high pressure electrostatic painting method to be sprayed on surface treated phosphatization model, according to condition require solidification.

The properties test result of the powder coating that table 3 vibrin is made:

Table 3 illustrates: by being found out by polyester resin powdered coating, the Weather-resisting powder coating that embodiment 4,5,6 is made in impact property, paint film adhesion, hardness of paint film, weathering resistance (temper(ing) of 500h ultraviolet) protect basic indifference in light rate, can meet whole use propertieies of Weather-resisting powder coating; By polyester resin powdered coating can be found out, the mixed powder coating that embodiment 1,2,3 and 7 vibrin is made in impact property, paint film adhesion, excellent in hardness of paint film, powder storage etc., whole use propertieies of mixed powder coating can be met.

The powder coating made by embodiment 1 to the embodiment 7 vibrin product synthesized by processing method disclosed by the invention can reach completely excellent in various over-all properties, can meet the various requirement of suitability for industrialized production.

Table 4 adopts PTA to be raw material and adopts PET to be that raw material compares with the interrupter method production advantage:

Claims

1. continuous processing prepares a method for polyester resin for powder coating, the steps include:

1) polyethylene terephthalate is added screw extrusion press continuously, controlling screw extrusion press temperature is 180 ~ 280 DEG C, polyethylene terephthalate melt-stoichiometry is expressed in alcoholysis reaction still, in reactor, is metered into catalyzer and the boiling point dibasic alcohol higher than ethylene glycol simultaneously; Control reacting kettle inner pressure is 0.1MPa ~ 6MPa, temperature is 150 ~ 260 DEG C, and material total residence time is 0.5h ~ 6h;

Described polyethylene terephthalate and the mass ratio of dibasic alcohol are 1:0.5 ~ 3; Described catalyzer accounts for 0.1 ‰ ~ 5 ‰ of polyethylene terephthalate quality;

Described dibasic alcohol is neopentyl glycol, special pentanediol, methyl propanediol, Diethylene Glycol, 1,3-PD, BDO or 1,4 cyclohexane dimethanol;

2) when step 1) described in dibasic alcohol when being neopentyl glycol, by step 1) gained material at the uniform velocity quantitatively adds in knockout tower after 50 ~ 200 order filtering and impurity removings, import entrainer continuously simultaneously, control separator internal pressure is 40KPa ~ 100KPa, temperature is 130 ~ 230 DEG C, control to be separated tower top temperature 90 ~ 150 DEG C, material is fractionation by distillation 2 ~ 8h in knockout tower, is continuously separated out the azeotrope of entrainer and ethylene glycol simultaneously;

Or

When step 1) described in dibasic alcohol be methyl propanediol, Diethylene Glycol, 1, ammediol, 1,4-butyleneglycol, special pentanediol or 1, during 4-cyclohexanedimethanol, by step 1) gained material at the uniform velocity quantitatively adds in knockout tower after 50 ~ 200 order filtering and impurity removings, under normal pressure, controls that temperature in separator is 130 ~ 250 DEG C, to control to be separated tower top temperature be 150 ~ 210 DEG C, material is fractionation by distillation 1 ~ 8h in knockout tower, is continuously separated out ethylene glycol;

3) by step 2) process terminate after material be at the uniform velocity transferred to reaction kettle of the esterification, add polyprotonic acid and/or the acid anhydrides corresponding with polyprotonic acid, polyvalent alcohol, stablizer, catalyzer simultaneously, under normal pressure, control esterification temperature in the kettle is 200 ~ 260 DEG C, reaction kettle of the esterification mixing speed is 20 ~ 60 revs/min, and material is at reaction kettle of the esterification lactonization reaction 0.5 ~ 5h;

In esterification reaction process, sampling on-line monitoring acid number and viscosity: when preparing product is epoxy/polyester mixed polyester resin used for powder coating, detection acid number is 10 ~ 40mgKOH/g, 150 ± 5 DEG C of monitoring viscosities are 10 ~ 100cP, and esterification terminates; When preparing product is pure polyester type vibrin used for powder coating, monitoring acid number is 20 ~ 60mgKOH/g, 200 DEG C of monitoring viscosities are 0.5 ~ 30cP, and esterification terminates;

In described esterification reaction process, controlling to be separated tower top temperature is 95 ~ 105 DEG C, isolates the water of generation;

Described polyprotonic acid is selected from one or more in following substances: diprotic acid, triprotic acid, tetraprotic acid; Described diprotic acid and/or the acid anhydrides corresponding with diprotic acid account for 15 ~ 40Wt.% of polyethylene terephthalate; Described triprotic acid and/or the acid anhydrides corresponding with triprotic acid account for 1 ~ 10Wt.% of polyethylene terephthalate; Described tetraprotic acid and/or the acid anhydrides corresponding with tetraprotic acid account for 0.5 ~ 3Wt.% of polyethylene terephthalate;

Described stablizer accounts for 0.05 ~ 0.5Wt.% of polyethylene terephthalate; Described catalyzer accounts for 0.1 ~ 0.5Wt.% of polyethylene terephthalate;

4) by step 3) esterification terminate after material through 50 ~ 200 orders filter after be at the uniform velocity transferred in polymerization reaction kettle, control reacting kettle inner pressure is 0.1KPa ~ 50KPa, temperature is 220 ~ 280 DEG C, polyreaction 0.5 ~ 5h;

On-line monitoring acid number and viscosity: when preparing product is epoxy/polyester mixed polyester resin used for powder coating, sampling detection acid number is 5 ~ 20mgKOH/g, 200 DEG C of monitoring viscosities are 5 ~ 50cP, and polyreaction terminates; When preparing product is pure polyester type vibrin used for powder coating, sampling detection acid number is 20 ~ 50mgKOH/g, 200 DEG C of monitoring viscosities are 10 ~ 100cP, and polyreaction terminates;

5) by step 4) polyreaction terminate after material be transferred in next reactor, add trimellitic acid 1,2-anhydride simultaneously, control temperature is 200 ~ 230 DEG C, reacts after 1 ~ 2 hour, and reducing temperature of charge is 160 ~ 180 DEG C, add curing catalyst again, under normal pressure, reactor mixing speed is 20 ~ 120 revs/min, stirs 0.5 ~ 1h, mix, after filtration, extrude, cool, pulverize to obtain epoxy/polyester mixed polyester resin used for powder coating;

Described trimellitic acid 1,2-anhydride accounts for 5 ~ 30Wt.% of polyethylene terephthalate; Described curing catalyst is 1816 tertiary amines; Described curing catalyst accounts for 0.5 ~ 15Wt.% of polyethylene terephthalate;

Or

By step 4) polyreaction terminate after material be transferred in next reactor, add curing catalyst simultaneously, under normal pressure, controlling temperature of reaction kettle is 180 ~ 230 DEG C, reactor mixing speed is 20 ~ 120 revs/min, stir 0.5 ~ 2h, mix, after filtration, extrude, cool, pulverize to obtain pure polyester type vibrin used for powder coating;

Described curing catalyst is triphenyl ethyl phosphonium bromide phosphorus or triphenyl phosphorus; Described curing catalyst accounts for 0.1 ~ 10Wt.% of polyethylene terephthalate.

2. a kind of continuous processing according to claim 1 prepares the method for polyester resin for powder coating, it is characterized in that: step 1) described in polyethylene terephthalate be regeneration reclaim polyethylene terephthalate, wherein, the mass percentage of polyethylene terephthalate is greater than 90%.

3. a kind of continuous processing according to claim 2 prepares the method for polyester resin for powder coating, it is characterized in that: the polyethylene terephthalate that described regeneration is reclaimed is selected from one or more in following substances: PET packing material, PET polyester material, the textile of polyester material, clothing material.

4. a kind of continuous processing according to any one of claim 1 to 3 prepares the method for polyester resin for powder coating, it is characterized in that: step 1) and step 3) described in catalyzer be: antimony system, germanium system, titanium system, tin series catalysts.

5. a kind of continuous processing according to any one of claim 1 to 3 prepares the method for polyester resin for powder coating, it is characterized in that: step 1) and step 3) described in catalyzer be: antimonous oxide, antimony acetate, antimony glycol, tetrabutyl titanate, manganese acetate, zinc acetate, calcium acetate or Cobaltous diacetate.

6. a kind of continuous processing according to any one of claim 1 to 3 prepares the method for polyester resin for powder coating, it is characterized in that: step 2) described in entrainer be: dimethylbenzene, toluene, ethylbenzene, normal hexane, hexanaphthene, own dioxane methyl alcohol or acetone;

Step 2) described in the azeotrope of entrainer and ethylene glycol be separated by phase splitter and obtain entrainer and ethylene glycol, entrainer recycles, glycol recovery; In phase splitter sepn process, control temperature of charge 5 ~ 30 DEG C.

7. a kind of continuous processing according to any one of claim 1 to 3 prepares the method for polyester resin for powder coating, it is characterized in that: step 3) described in diprotic acid be selected from following substances one or more: terephthalic acid, m-phthalic acid, phthalic acid, fumaric acid, 1,4 cyclohexanedicarboxylic acid, hexanodioic acid, pentanedioic acid or sebacic acid; Described triprotic acid is TMLA, and the acid anhydrides that described triprotic acid is corresponding is trimellitic acid 1,2-anhydride; The acid anhydrides that described tetraprotic acid is corresponding is pyromellitic dianhydride;

Described dibasic alcohol is selected from one or more in following substances: neopentyl glycol, methyl propanediol, Diethylene Glycol, 1,3-PD, BDO, special pentanediol, 1,4 cyclohexane dimethanol; Described trivalent alcohol is selected from one or more in following substances: glycerol, TriMethylolPropane(TMP), trimethylolethane; Described tetravalent alcohol is tetramethylolmethane.

8. a kind of continuous processing according to any one of claim 1 to 3 prepares the method for polyester resin for powder coating, it is characterized in that: step 3) described in stablizer be selected from following substances one or more: phosphoric acid, phosphorous acid, phosphoric acid ester, phosphorous acid ester.

9. continuous processing prepares a method for polyester resin for powder coating, the steps include:

A) by dibasic alcohol and/or trivalent alcohol, stablizer, catalyst mix making beating, be warming up to 100 ± 10 DEG C, add terephthalic acid again, be stirred to material dispersed in slurry form, join in reaction kettle of the esterification with constant speed by above-mentioned mixed slurry, controlling temperature in esterifier is 250 ± 10 DEG C, carries out esterification under normal pressure, controlling tower top temperature is 100-105 DEG C of esterification water of discharging generation, and the total residence time of material in esterifier is 5 ± 0.5 hours;

Described dibasic alcohol and/or trivalent alcohol account for 65 ~ 85Wt.% of terephthalic acid; Described stablizer accounts for 0.05 ~ 0.1Wt.% of terephthalic acid; Described esterifying catalyst accounts for 0.1 ~ 0.2Wt.% of terephthalic acid;

B) by step a) gained carboxylate be transferred to the second esterifier with constant speed, add diprotic acid, stablizer to the second esterifier simultaneously, the temperature controlling the second esterifier is 250 ± 10 DEG C, under normal pressure, carry out esterification, control tower top temperature is 95-105 DEG C, and the total residence time of material in the second esterifier is 5 ± 1 hours;

Described diprotic acid accounts for 5 ~ 20Wt.% of terephthalic acid; Described stablizer accounts for 0.05 ~ 0.1Wt.% of terephthalic acid;

C) by step b) esterification terminate after material be at the uniform velocity transferred in polymerization reaction kettle after 50 ~ 200 orders filter, control that batch condensation polymerization reactor internal pressure is 0.1KPa ~ 50KPa, temperature is 220 ~ 280 DEG C, polyreaction 0.5 ~ 6h;

On-line monitoring acid number and viscosity: when preparing product is epoxy/polyester mixed polyester resin used for powder coating, sampling detection acid number is 5 ~ 20mgKOH/g, 200 DEG C of monitoring viscosities are 5 ~ 50cP, and condensation reaction terminates; When preparing product is pure polyester type vibrin used for powder coating, sampling detection acid number is 20 ~ 50mgKOH/g, 200 DEG C of monitoring viscosities are 10 ~ 100cP, and polyreaction terminates;

D) by step c) polyreaction terminate after material be transferred in next reactor, add trimellitic acid 1,2-anhydride simultaneously, control temperature is 200 ~ 220 DEG C, reacts after 1 ~ 2 hour, and adjustment temperature of charge is 160 ~ 180 DEG C, add curing catalyst again, under normal pressure, reactor mixing speed is 20 ~ 120 revs/min, stirs 0.5 ~ 1h, mix, after filtration, extrude, cool, pulverize to obtain epoxy/polyester mixed polyester resin used for powder coating;

Described trimellitic acid 1,2-anhydride accounts for 15 ~ 20Wt.% of terephthalic acid; Described curing catalyst is 1816 tertiary amines; Described curing catalyst accounts for 1 ~ 3Wt.% of terephthalic acid;

Or

By step c) polycondensation terminate after material at the uniform velocity move in next reactor, add curing catalyst simultaneously, under normal pressure, controlling temperature of reaction kettle is 180 ~ 230 DEG C, mixing speed is 20 ~ 120 revs/min, stir 0.5 ~ 2h, mix, after filtration, extrude, cool, pulverize to obtain pure polyester type vibrin used for powder coating;

Described curing catalyst is triphenyl ethyl phosphonium bromide phosphorus or triphenyl phosphorus; Described curing catalyst accounts for 0.1 ~ 0.3Wt.% of terephthalic acid.

10. a kind of continuous processing according to claim 9 prepares the method for polyester resin for powder coating, it is characterized in that: step a) described in dibasic alcohol be selected from following substances one or more: neopentyl glycol, methyl propanediol, Diethylene Glycol, 1, ammediol, 1,4-butyleneglycol, special pentanediol, 1,4 cyclohexane dimethanol; Described trivalent alcohol is: glycerol and/or TriMethylolPropane(TMP); Described stablizer is selected from one or more in following substances: phosphoric acid, phosphorous acid, phosphoric acid ester, phosphorous acid ester; Described catalyzer is: antimony system, germanium system, titanium system, tin series catalysts.