阅读说明：本技术 一种利用微气泡制备乙烯聚合物的方法 (It is a kind of to prepare polyvinyl method using microbubble ) 是由 王靖岱 叶姝瑶 戴进成 历伟 孙婧元 阳永荣 黄正梁 杨遥 蒋斌波 叶健 李羽 于 2019-08-12 设计创作，主要内容包括：本发明公开了一种利用微气泡制备乙烯聚合物的方法,属于烯烃聚合领域。原料气体通过微气泡发生器以微气泡的形式进入聚合反应器并在催化剂的作用下参与聚合反应；其中,所述微气泡在淤浆反应体系中逐渐变小或消失,微气泡所携带的原料气体在溶剂中充分溶解并混合均匀。本发明制备的乙烯聚合物具有较窄的分子量分布范围、较高的撕裂强度、较高的冲击强度、较高的韧性和较高的透明度等优点。(Polyvinyl method is prepared using microbubble the invention discloses a kind of, belongs to field of olefin polymerisation.Unstrpped gas is entered polymer reactor microbubble generator in the form of microbubble and participates in polymerization reaction under the effect of the catalyst；Wherein, the microbubble gradually becomes smaller or disappears in slurry reaction system, and unstrpped gas entrained by microbubble is sufficiently dissolved and is uniformly mixed in a solvent.Ethene polymers prepared by the present invention has many advantages, such as relatively narrow range of molecular weight distributions, higher tearing strength, higher impact strength, higher toughness and higher transparency.)

1. a kind of prepare polyvinyl method using microbubble, it is characterised in that: unstrpped gas passes through microbubble generator Enter polymer reactor in the form of microbubble and participates in polymerization reaction under the effect of the catalyst；Wherein, the microbubble exists It gradually becomes smaller or disappears in slurry reaction system, unstrpped gas entrained by microbubble is sufficiently dissolved in a solvent and mixed It is even.

2. the method according to claim 1, wherein the unstrpped gas includes that ethylene, hydrogen and/or copolymerization are single Body.

3. according to the method described in claim 2, it is characterized in that, the comonomer to be preferably at least a kind of carbon atom number big In the alpha-olefin equal to 3 and less than or equal to 10.

4. the method according to claim 1, wherein the microbubble generator is by one or more micro-pore aerations Head composition, the percent opening of micro porous aeration head are 10%~80%, are placed in polymer reactor bottom, the micropore material of micro porous aeration head Material is selected from ceramics, SPG film, metal sintering porous media, polycarbonate membrane or polystyrene film.

5. according to the method described in claim 4, it is characterized in that, the microbubble diameter generated by microbubble generator is 10^-6~10^-3M, the volume fraction that the microbubble accounts for solvent in slurry reaction system is 20%~90%.

6. the method according to claim 1, wherein the polymer reactor is slurry stirred autoclave or slurry Annular-pipe reactor.

7. method according to claim 1 or 6, which is characterized in that the solvent in the slurry reaction system is selected from C3- The alkane of C10.

8. the method according to claim 1, wherein the catalyst is selected from Ziegler-Natta catalyst, cyclopentadienyl gold Metal catalyst, transition-metal catalyst, inorganic chrome catalysts and organic chrome catalysts.

9. method according to claims 1 to 8, which is characterized in that the polymeric reaction temperature is 60~90 DEG C；It is described poly- Conjunction reaction pressure is 0.1~10MPa；Wherein, polymerization pressure is made of ethylene partial pressure and hydrogen partial pressure, the air inflow of hydrogen It is the 0.01%~30% of ethylene air inflow.

10. it is a kind of according to claim 1~any one of 9 described in the ethene polymers that is prepared of method.

Technical field

Polyvinyl method is prepared the present invention relates to a kind of, and in particular to a kind of utilize is drawn in slurry polymerization system The microbubble for entering unstrpped gas dissolves unstrpped gas sufficiently in a solvent and is uniformly mixed to prepare polyvinyl side Method.

Background technique

It is well known that polyethylene is a kind of thermoplastic resin as made of vinyl polymerization, it is that modern petrochemical industry is most important One of product, with excellent property and good processing performance, be widely used in various fields.The polymerization work of ethylene Skill mainly has slurry process, vapor phase method, solwution method etc..And slurry process industrializes morning time, mature technology, product due to it Preferably, therefore one of the main technology of China's production polyethylene can be had become now.

In traditional slurry polymerization processes, typical method is that chain-transferring agent is served as using hydrogen to adjust the molten of product Melt index and molecular weight, i.e., make before the reaction the hydrogen, ethylene and the comonomer of gasification of certain pressure by gas line into Enter the bottom of polymerization reaction kettle, while is scattered in unstrpped gas in solvent using blender, and exist under the effect of the catalyst Polymerization reaction is carried out in solvent.But the technical process have the defects that it is certain, i.e., the solubility of unstrpped gas in a solvent compared with It is low and be difficult to uniformly mix, cause the local concentration of unstrpped gas in slurry polymerization system higher, to the property of polymerizate It affects.In polymerization process, though the solubility of ethylene in a solvent is higher, if further it can be made to fill Divide dissolution, then can improve the activity of polymerizate to a certain extent.In addition, the higher density of hydrogen in part makes the region chain Metastasis degree increases, and the molecular weight of the region clustering product reduces, and melt index suddenly increases.This may cause solvable in polymerizate Component increases, and converted products such as food pack and water pipe of polymerizate etc. is made to release small molecule object under the high temperature conditions Matter causes food-safety problem.This may also cause squeezing out and discharging smell and flue gas in the resins process such as blown film, together When due to polymerizate melt fluidity raising, mechanical performance sharp fall generates extremely severe shadow to processing performance It rings.

Chinese patent CN105017454B discloses a kind of preparation method of linear low density polyethylene, by with alkyl aluminum Preactivated support type TiCl₄/MgCl₂Catalyst is major catalyst, and alkyl aluminum is co-catalyst, H₂As molecular weight regulator, So that ethylene and alpha-olefin is carried out slurry polymerization, obtains linear low density polyethylene.But the unstrpped gas of this method is in solvent In be difficult to be uniformly mixed and lead to the polymer molecular weight wider distribution that is prepared, the part of low molecular weight is too low, and is easy There is the problems such as above-mentioned food safety and processing difficulties referred to.

From the above considerations, the present inventor is studied, it is therefore an objective to it is sudden and violent to solve related fields prior art institute The problem of exposing causes as the solubility of unstrpped gas in a solvent is lower, unstrpped gas is difficult to uniformly mix in a solvent The problems such as local concentration is higher is intended to provide the utilization microbubble that one kind effectively solves the above problems and prepares polyvinyl side Method.

Summary of the invention

In view of the above the deficiencies in the prior art, ethylene is prepared using microbubble one of the objects of the present invention is to provide a kind of The method of polymer.Due to the reduction with bubble size, the mass-transfer efficiency of bubble is improved, the rate of climb reduces, the residence time increases Long and blasting energy increases, so the method achieve draw using in slurry polymerization system by the above feature of microbubble The microbubble for entering unstrpped gas dissolves unstrpped gas sufficiently in a solvent and is uniformly mixed to prepare ethene polymers product. Method and process of the invention is simple, narrow with range of molecular weight distributions using ethene polymers prepared by method of the invention, The features such as activity is high effectively improves the tearing strength of resin, impact strength, punctures wearability, toughness and transparency, to product Processing performance has a degree of improvement.

Another object of the present invention is to provide a kind of ethene polymers being prepared according to the method.

According to an aspect of the present invention, the present invention provide it is a kind of prepare polyvinyl method using microbubble, Be characterized in that: unstrpped gas microbubble generator is entered polymer reactor in the form of microbubble and in the effect of catalyst Lower participation polymerization reaction；Wherein, the microbubble gradually becomes smaller or disappears in slurry reaction system, original entrained by microbubble Material gas is sufficiently dissolved and is uniformly mixed in a solvent.

In the method for the invention, the unstrpped gas includes ethylene, hydrogen and/or comonomer.Wherein, comonomer Enter polymer reactor after evaporator heating and gasifying.

In the method for the invention, the comonomer is preferably at least a kind of carbon atom number and is more than or equal to 3 and is less than Alpha-olefin equal to 10 is selected from propylene, 1- butylene, 1- amylene, 1- hexene, 1- octene and 1- decene, preferably propylene, 1- butylene.

In the method for the invention, the microbubble generator is placed in polymer reactor bottom, by one or more micro- Hole aeration head composition, the percent opening of micro porous aeration head are 10~80%, increase dispersion range of the bubble in solvent, moreover it is possible to rise To the effect for promoting polymer.The poromerics of microbubble generator is selected from ceramics, SPG film (Shirasu Porous Glass), metal sintering porous media, polycarbonate membrane, polystyrene film etc., preferably ceramic and metal sintering porous media.By The microbubble diameter that microbubble generator generates is 10^-6~10^-3M, preferably 10^-5~10^-4M, the microbubble account for slurry reaction body The volume fraction of solvent is 20%~90%, preferably 30%~70% in system

In the method for the invention, the polymer reactor is slurry stirred autoclave or slurry loop reactor.

A specific embodiment according to the present invention, the solvent in the slurry reaction system are selected from the alkane of C3-C10, It is preferred that normal heptane, n-hexane.

In the method for the invention, the catalyst is selected from Ziegler-Natta catalyst, metallocene catalyst, transition gold Metal catalyst, inorganic chrome catalysts and organic chrome catalysts, preferably Ziegler-Natta catalyst.

A specific embodiment according to the present invention, the polymeric reaction temperature are 60~90 DEG C, preferably 65~80 DEG C.Institute Stating polymerization pressure is 0.1~10MPa, preferably 0.1~4MPa.Wherein, polymerization pressure is by ethylene partial pressure and hydrogen point Pressure composition, the air inflow of hydrogen is the 0.01%~30% of ethylene air inflow, preferably 0.1%~20%.

According to another aspect of the present invention, the present invention provides a kind of vinyl polymerizations being prepared according to the method Object.The ethene polymers at least has following any feature:

1) polyvinyl molecular weight is 1000~1000000, preferably 10000~1000000.

2) polyvinyl molecular weight distributing index is 1~20, preferably 1~6.

3) polyvinyl melt index is that 10~80g/10min (is measured, 230 DEG C/2.16kg, i.e., according to ISO1133 Measured in the case where 230 DEG C and 2.16kg pressure), preferably 10~50g/10min.

Compared with prior art, the present invention introduces the microbubble of unstrpped gas because of utilization in slurry polymerization system, because This efficiently solve that the prior art exposes as the solubility of unstrpped gas in a solvent is lower, unstrpped gas is difficult in solvent In the technical problems such as uniformly mix and cause local concentration higher.The polymerization process is simple, improves polymerizate activity, And improves product processing performance to a certain extent and improve the safety of converted products.

According to another aspect of the present invention, a kind of ethene polymers being prepared according to the above method is additionally provided. Ethene polymers prepared by the present invention have relatively narrow range of molecular weight distributions, higher polymerization activity, higher tearing strength, The advantages that higher impact strength, higher toughness and higher transparency.

Specific embodiment

Embodiment of the present invention is described in detail below in conjunction with embodiment.The following example is merely to illustrate this Invention, and should not be taken as limiting the scope of the invention.The person that is not specified actual conditions in embodiment, according to normal conditions or manufacturer It is recommended that condition carry out.Reagents or instruments used without specified manufacturer in embodiment, being can be by commercially available acquisition Conventional products.

The characterizing method of ethene polymers structure and performance:

1) weight average molecular weight (M_W) and molecular weight distributing index (PDI) characterization: gel permeation chromatography (GPC).

By sample to be tested with stabilisation 1,2,4- trichloro-benzenes (250 μ g/ml BHT (the CAS REGISTRY of 10mg/5ml NUMBER128-37-0 concentration preparation)；Then sample is heated to 170 DEG C of holding 2.5h to be dissolved；Measurement be WatersGPCV2000 is upper, carries out under the conditions of 145 DEG C, with the flow rate of 1.0ml/min, with identical stabilisation solvent； Three Polymer Lab columns are used in series (Plgel, 20 μm of mixing ALS, 300X 7.5mm).

2) it the characterization of melt flow index (MFR): is measured under the conditions of 230 DEG C/2.16kg according to ISO1133 method.