CN1330089A - Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density - Google Patents
Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density Download PDFInfo
- Publication number
- CN1330089A CN1330089A CN 01126421 CN01126421A CN1330089A CN 1330089 A CN1330089 A CN 1330089A CN 01126421 CN01126421 CN 01126421 CN 01126421 A CN01126421 A CN 01126421A CN 1330089 A CN1330089 A CN 1330089A
- Authority
- CN
- China
- Prior art keywords
- pva
- viscosity
- polymerization
- apparent density
- degree
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Landscapes
- Polymerisation Methods In General (AREA)
Abstract
A process for prepairng polyvinyl chloride resin with high apparent density by means of a novel disperse system features that the high-alcoholysis high-viscosity PVA(I), a certain substituted HPMC and low-alcoholysis low-viscosity PVA (II) are proportionally mixed while stirred to obtain the PVC resin with high apparent density. The resultant PVC resin dedicated for pipes features high machinability and quality, and low cost.
Description
Technical field
The present invention relates to the preparation method of polyvinyl chloride (PVC) RESINS, relate in particular to and adopt suspension polymerization to prepare the method for polyvinyl chloride (PVC) RESINS, particularly adopt suspension polymerization to prepare the dispersion agent of polyvinyl chloride (PVC) RESINS.
Background technology
The apparent density of polyvinyl chloride (PVC) RESINS is one of its important performance indexes, when using polyvinyl chloride resin, when particularly producing tubing, is keeping under the good plasticizing capacity prerequisite, and the user always wishes to have higher apparent density.The polyvinyl chloride resin advantage of high apparent density has: the speed when improving resin extrusion molding; It is little etc. to be easy to packing, transportation and storage volume, thereby improves service efficiency greatly.So improving the resin apparent density by all means is one of focus of the research of PVC manufacturing both at home and abroad now.
U.S. Goodrich company just specializes in and has made the spherical resin (US4 with high apparent density, 435,524), but its with partial cross-linked polyacrylic acid etc. as dispersion agent, to having relatively high expectations of production technique, make used additives also more special, thereby fail in worldwide, extensively to promote, rarely had the report of this respect now abroad.Some PVC manufacturerss reach the purpose (US5,342,906) that improves apparent density by the change power of agitator, but it requires height to agitation condition, need continuous conversion power of agitator in reaction, have increased the loaded down with trivial details degree of operation.
In recent years, along with suspension polymerization dispersant specification and kind, it mainly is the continuous increase of polyvinyl alcohol (PVA) and Vltra tears (HPMC) kind, patent (JP08,134,111) and (JP06,228,208) by adopting specific compound dispersing agent, methods such as conversion dispersion agent adding mode, combine with the stirring system, produce the high apparent density resin, processing condition are comparatively simple, but adopt ternary PVA compound dispersing agent to make the resin particle diameter become big easily, Tile Width broadens, and has increased the possibility that coarse fodder.Add mode and change dispersion agent, though after add the apparent density that dispersion agent can improve resin, the resin voidage is descended, influence the residual quantity of the oil absorbency and the vinyl chloride monomer (VC) of resin.
Summary of the invention
Technical problem to be solved by this invention provides the method that a kind of suspension polymerization that adopts compound dispersing agent prepares polyvinyl chloride (PVC) RESINS, make the polyvinyl chloride resin particle that makes regular, distribute and concentrate, keep certain voidage simultaneously, plasticizing capacity is better, and technology is simple, and is basic identical with general production of resins, equipment need not changed, and just can reach the purpose that improves the resin apparent density.
Technical conceive of the present invention is such:
When suspension polymerization of VC, monomer droplet is scattered in the water under stirring action, and dispersant adsorption is in the monomer droplet top layer, with stirring dispersion and the merging process that influences drop.Alcoholysis degree, viscosity with dispersion agent, or the difference of hydroxypropyl, methoxyl group substitution value, cause final PVC particulate generation type and result also to have greatest differences, by the conversion dispersion system, adjust the dispersion-Bao glue ability between water-liquid phase, just may make prepared polyvinyl chloride resin particle regular, distribute and concentrate, apparent density improves, and keeps suitable voidage.
The technical problem that will solve required for the present invention realizes by the following technical solutions:
High apparent density polyvinyl chloride (PVC) RESINS of the present invention is that a kind of apparent density is 0.55～0.65g/cm3, and 100g resin plasticizer specific absorption is more than 18g, and particle is regular, the polyvinyl chloride (PVC) RESINS of median size between 160～200 μ m.
The present invention be a kind of be monomer with vinylchlorid (VC), exist the low suspension polymerization to prepare the method for high apparent density polyvinyl chloride (PVC) RESINS at initiator and dispersion agent.Under dispersion agent and stirring action, the vinyl chloride monomer drop carries out coalescence and dispersion in water medium, forms polymer particle.More than used dispersion agent can be the polyvinyl alcohol of partial alcoholysis, methylcellulose gum, ethyl cellulose, Vltra tears, polyacrylic acid, gelatin etc.Temperature of reaction is 50～65 ℃, and the reaction times is 4～6 hours, pH=7～9.
Wherein use polyvinyl alcohol (PVA) and Vltra tears (HPMC) effect best.
The present invention is with a kind of high alcoholysis degree, and high viscosity PVA (I) is compound with the HPMC of certain substitution value, adds an amount of low alcoholysis level, low viscosity PVA (II), three kinds of dispersion agents are complementary with agitation condition with certain proportioning combination, make the polyvinyl chloride resin of high apparent density.
Wherein:
High alcoholysis degree, the consumption of high viscosity PVA (I) is 0.01～0.10% of a vinyl chloride monomer weight;
The consumption of HPMC is 0.01～0.10% of a vinyl chloride monomer weight;
Low alcoholysis level, the consumption of the oil soluble PVAC polyvinylalcohol (II) of low polymerization degree is 0.001～0.05% of a vinyl chloride monomer weight, preferably 0.01～0.10%.
Said high alcoholysis degree, alcoholysis degree 〉=75% (molar fraction) of high viscosity PVA (I), preferably 85%～98%.Alcoholysis degree is too low, and protection vinyl chloride monomer ability is not enough, and coalescence is frequent, makes the particle irregularity, and apparent density can not improve.The viscosity of PVA (I) is 30～120mPa.s, 50～100mPa.s preferably, when 4% concentration (20 ℃ measure down), and viscosity is too low, and it is not enough to protect the glue ability, and special-shaped bar is many, the particle irregularity; Viscosity is too high, makes the system dispersive ability not enough, makes the particle chap easily, and epidermis is hard, and crystal is many.
The methoxy content of said HPMC is 20～40%, preferably 25～35%; Hydroxypropyl content 5～15%, preferably 5～10%.Viscosity is 30～70mpas, and this viscosity is this solution of 4% concentration under 20 ℃, is preferably 35～60mpas;
Said low alcoholysis level, best 35～65% (molar fractions) of the alcoholysis degree of the oil soluble PVAC polyvinylalcohol (II) of low polymerization degree, the polymerization degree preferably 150～500.Dispersion aids can make the surface tension of system suitably reduce; play the guarantor's glue ability of coordination system and the effect of dispersive ability; make polymerization system when keeping certain protection drop ability; suitably take into account dispersive ability; thereby increase the internal voids rate of resin particle; and eliminated macrobead and fine particle, kept its good PVC to take off absorption energy and low residual amt.
More than three kinds of dispersion agents cooperate with certain proportion, form the dispersion system of polymerization of vinyl choride monomer jointly, influence resin particle characteristic and apparent density, voidage etc.The adding mode of these three kinds of dispersion agents can be to begin preceding adding in polymerization, also can be that a part begins preceding adding in polymerization, another part begins certain hour in polymerization and adds, after add the apparent density that dispersion agent can improve resin, but the voidage of resin will be descended, and make technology numerous and diverse, thereby adopt the sort of adding mode to decide actually by specific requirement to resin property.Adopt the dispersion system of being carried among the present invention, can directly add dispersion agent in the polymeric kettle before polymerization begins, the polymerization that heats up can obtain the polyvinyl chloride resin than high apparent density.
The stirring system is another important factor that influences resin particle form and apparent density.The shape and the structure of the polymeric kettle that uses among the present invention are not particularly limited, and can use the polymeric kettle that uses traditionally.Stirring rake can be used oar formula stirring rake, the Fa Edela oar, and cloth Shandong Makin stirring rakes etc. in above-mentioned stirring rake, preferably use oar formula stirring rake.Plate washer preferably is set in the polymeric kettle, and form is unrestricted, and power of agitator is preferably in 0.8～1.5kw/m
3Scope.Power of agitator is too small, causes particle that chap trend is arranged, and power of agitator increases, and particle attenuates, and apparent density descends, and power of agitator increases to a certain amount of, and monomer droplet generation coalescence chance is increased, and average particle size rises again.
Need to add initiator in the polyreaction, here to initiator and have no special requirements, can be according to conveniently selecting organic peroxide evocating agent for use, initiator can be the new enanthic acid tert-butyl ester of peroxidation, the special pentyl ester of peroxidation trimethylacetic acid, peroxide tert pivalate ester, peroxy dicarbonate be two-and in the organic peroxide evocating agents such as (2-ethylhexyls) one or more are compound, and its add-on is 0.01～0.1% (with respect to the weight percent of vinyl chloride monomer).Initiator can be squeezed into polymeric kettle with volume pump after vinyl chloride monomer adds, polymerization then heats up.
Polyreaction also need add de-salted water, and water plays the effect that moves heat and conduct dispersion small droplets carrier.The desalination water yield that adds, promptly water-oil ratio (de-salted water and monomer weight ratio) can be 0.9/1 to 1.5/1, preferably 1.0/1 to 1.3/1, water-oil ratio is less than 0.9/1, and polyreaction occurs unstable, resin particle distributes and broadens, and a large amount of macrobeads and " flake " occur.If it is just difficult that water-oil ratio, improves apparent density greater than 1.5/1.
During VC suspension polymerization, the pH value of system is influential to polymerization process speed and dispersion agent dispersion effect, and the pH value of general system should be controlled at neutral alkali partially.Decomposite a part of HCl during the VC polymerization, the pH value of system is descended, thereby the pH value that needs a certain amount of buffer reagent of adding to regulate polymerization system, sodium hydroxide, sodium bicarbonate, bicarbonate of ammonia etc. all can be used as buffer reagent, for improving the maximum still sodium bicarbonate of apparent density contribution, it can improve the resin particle form, and the particle regularity is improved, distribution narrow, thus the apparent density of resin improved.
Adopt dispersion system of the present invention and agitation condition, the polyvinyl chloride (PVC) RESINS of the high apparent density that is obtained, processing characteristics is good, the dispersion agent that adopts among the present invention is commercial new variety, source and quality can guarantee, the stirring system is not changed substantially, processing condition are comparatively simple, simultaneously can guarantee the resin particle degree again, the internal voids rate, thereby compare with the patent that high apparent density polyvinyl chloride resin is produced in other introduction, processing condition change few, the resin quality excellence has significantly technology and cost advantage.
The specific embodiment
Embodiment 1
Polymerisation is two layers of flat oar of two leaves in stirring, and four baffle plates, volume are in the Stainless Steel still of 300L Carry out, water-oil factor is decided to be 1.26/1. Technical process is summarized as follows: earlier with 126kg desalted water, 0.03kg branch Powder A, 0.03kg B, 0.008kg C, pH adjusting agent solid NaOH powder 0.02kg drop in the still, Vacuumize rear adding VCM 100kg, be pressed into 0.050kg initator peroxy dicarbonate two-(2-second The own ester of base), the startup speed of agitator is 220rpm, is warming up to 57 ℃ of beginning polymerizations 5 hours, keeps the polymerization temperature Degree is down to 0.6Mpa to polymerization pressure, adds 0.015kg terminator acetone contracting amido thiocarbamide, reclaims remaining single Discharging behind the body. Slurry is tested then through centrifugal post-drying. Test result is as follows: the degree of polymerization is 1025, table Seeing density is 0.58 (g/cm3), oil absorbency is 20 (g), average grain diameter 178.5 (μ m), the dispersion of distribution Be 0.620. Prepared resin particle control is fairly good, substantially be regular shape, and interior porosity keeps Good, do not have brilliant point and transparence particle and exist.
Above dispersant A is alcoholysis degree 98% (molar fraction), and viscosity is that (20 ℃, 4% is molten for 48mPa.s Under the liquid concentration conditions) PVA; Dispersant B is methoxy substitution degree 25%, hydroxypropyl substitution value 6%, The HPMC of viscosity 50mpa.s (20 ℃, under the 4% solution concentration condition); Dispersing agent C is alcoholysis degree 50% (molar fraction), the PVA of viscosity 4.0mPa.s (20 ℃, under the 4% solution concentration condition).
Embodiment 2
Change the addition of dispersant A into 0.02kg, the B addition changes 0.04kg into, and the C addition still is 0.08kg, and other process conditions are with embodiment 1, and its result is as follows: the degree of polymerization is 1030, and apparent density is 0.57 (g/cm3), oil absorbency is 21 (g), average grain diameter 175.3 (μ m), and the dispersion of distribution is 0.625, with reality Execute example 1 relatively, apparent density slightly has decline, and oil absorbency slightly improves.
Embodiment 3
With alcoholysis degree 93%, viscosity is the dispersant A of the PVA alternative embodiment 1 of 70mpa.s (20 ℃, under the 4% solution concentration condition), and process conditions are with embodiment 1, test result is as follows: the degree of polymerization is 1025, and apparent density is 0.592 (g/cm3), oil absorbency is 19 (g), average grain diameter 181.4 (μ m), and it is wide to distribute Degree is 0.622.
Comparative example 1
When polymerization, add 0.025kg dispersant A, 0.025kg dispersant B, 0.018kg dispersing agent C, its Its process conditions is with embodiment 1. Test result is as follows: the degree of polymerization is 1020, and apparent density is 0.510 (g/cm3), oil absorbency is 29 (g), average grain diameter 130.5 (μ m), and the dispersion of distribution is 0.856.
Comparative example 2
When polymerization, add 0.03kg dispersant A, 0.03kg dispersant E, 0.008kg dispersing agent C. A, C dispersant specification is with embodiment 1, and other process conditions are with embodiment 1. Dispersant E is the methoxy substitution degree 29.5%, hydroxypropyl substitution value 8.0%, the HPMC of viscosity 48mPa.s (20 ℃, under the 4% solution concentration condition), Test result is as follows: the degree of polymerization is 1030, and apparent density is 0.540 (g/cm3), oil absorbency is 22 (g), Average grain diameter 155.4 (μ m), the dispersion of distribution is 0.790.
Comparative example 3
Add 0.03kg dispersant B, 0.03kg dispersant D, 0.008kg dispersing agent C, other worker during polymerization The skill condition is with embodiment 1. Dispersant B, C specification are with embodiment 1, and dispersant D alcoholysis degree 80% glues The PVA of degree 48mpa.s (20 ℃, under the 4% solution concentration condition). Test result is as follows: the degree of polymerization is 1030, Apparent density is 0.530 (g/cm3), oil absorbency is 23 (g), average grain diameter 148.9 (μ m), and it is wide to distribute Degree is 0.856.
Comparative example 4
Add the 0.03kg dispersant A, 0.03kg dispersant B, 0.008kg dispersant F, other process conditions With embodiment 1. Dispersant A, B specification are with embodiment 1, and F is alcoholysis degree 72%, and viscosity 45mpa.s (20 ℃, under the 4% solution concentration condition) PVA. It is as follows to make the resin result: the degree of polymerization is 1035, and is apparent Density is 0.610 (g/cm3), oil absorbency is 17 (g), average grain diameter 193.5 (μ m), and the dispersion of distribution is 0.780.
Following table is the summary sheet of each embodiment and comparative example.
Annotate: W%, expression is to the percentage by weight of VC monomer;
| Dispersant | Test result | |||||||||
| A (W％) | B (W％) | C (W％) | D (W％) | E (W％) | F (W％) | BD (g/cm 3) | DOP (g) | Average grain diameter (μ m) | The dispersion of distribution | |
| Embodiment 1 | 0.03 | 0.03 | 0.008 | 0.580 | 20 | 178.5 | 0.620 | |||
| Embodiment 2 | 0.02 | 0.04 | 0.008 | 0.570 | 21 | 175.3 | 0.625 | |||
| Embodiment 3 | 0.03(A 1) | 0.03 | 0.008 | 0.592 | 19 | 181.4 | 0.622 | |||
| Comparative example 1 | 0.025 | 0.025 | 0.018 | 0.481 | 27 | 130.5 | 0.856 | |||
| Comparative example 2 | 0.03 | 0.008 | 0.03 | 0.540 | 22 | 155.4 | 0.790 | |||
| Comparative example 3 | 0.03 | 0.008 | 0.03 | 0.530 | 23 | 148.9 | 0.856 | |||
| Comparative example 4 | 0.03 | 0.03 | 0.008 | 0.610 | 16 | 197.5 | 0.780 | |||
A represents alcoholysis degree 98% (molar fraction), viscosity be 48mPa.s (20 ℃, 4% solution concentration condition PVA down);
A
1Represent alcoholysis degree 93% (molar fraction), viscosity be 70mPa.s (20 ℃, 4% solution concentration condition PVA down);
B representation methoxy substitution value 25%, hydroxypropyl substitution value 6%, (20 ℃, 4% is molten for viscosity 50mpa.s Under the liquid concentration conditions) HPMC;
C represents alcoholysis degree 50% (molar fraction), viscosity 4.0mPa.s (20 ℃, under the 4% solution concentration condition) PVA;
D represents alcoholysis degree 80%, the PVA of viscosity 48mpa.s (20 ℃, under the 4% solution concentration condition);
E representation methoxy substitution value 29.5%, hydroxypropyl substitution value 8.0%, viscosity 48mPa.s (20 ℃, 4% Under the solution concentration condition) HPMC;
F represents alcoholysis degree 72%, the PVA of viscosity 45mpa.s (20 ℃, under the 4% solution concentration condition).
Claims (8)
1. method that adopts novel dispersion system to produce the high apparent density polyvinyl chloride resin dedicated for pipes, comprise with vinylchlorid being monomer, in the presence of initiator and dispersion agent, carry out suspension polymerization, it is characterized in that, said dispersion agent comprises high alcoholysis degree, high viscosity PVA (I), HPMC and low alcoholysis level, low viscosity PVA (II);
High alcoholysis degree, molar fraction alcoholysis degree 〉=75% of high viscosity PVA (I), the viscosity of PVA (I) is 30～120mPa.s, and the methoxy content of HPMC is 20～40%, and the viscosity of 5～15%, 20 ℃ of following 4% concentration of hydroxypropyl content is 30～70mpas; Low alcoholysis level, the molar fraction alcoholysis degree of the oil soluble PVAC polyvinylalcohol (II) of low polymerization degree is 35～65%, the polymerization degree is 150～500.
2. the method for claim 1 is characterized in that, the consumption of PVA (I) is 0.01～0.10% of a vinyl chloride monomer weight; The consumption of HPMC is 0.01～0.10% of a vinyl chloride monomer weight; The consumption of PVA (II) is 0.001～0.05% of a vinyl chloride monomer weight.
3. method as claimed in claim 2 is characterized in that, the consumption of PVA (II) is 0.01～0.10% of a vinyl chloride monomer weight.
4 the method for claim 1 is characterized in that, three kinds of dispersion agents add before polymerization begins or add a part before polymerization begins, and another part begins certain hour in polymerization and adds.
5. the method for claim 1 is characterized in that, high alcoholysis degree, and the molar fraction alcoholysis degree of high viscosity PVA (I) is 85%～98%, and the viscosity of PVA (I) is 50～100mPa.s, and the methoxy content of HPMC is 25～35%; Hydroxypropyl content is that the viscosity of 4% concentration is 35～60mpas under 5～10%, 20 ℃.
6. the method for claim 1 is characterized in that, adopts oar formula stirring rake, and power of agitator is 0.8～1.5kw/m
3
7. method as claimed in claim 2 is characterized in that, three kinds of dispersion agents add before polymerization begins or add a part before polymerization begins, and another part begins certain hour in polymerization and adds.
8. method as claimed in claim 7 is characterized in that, adopts oar formula stirring rake, and power of agitator is 0.8～15kw/m
3
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011264217A CN1190449C (en) | 2001-08-07 | 2001-08-07 | Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CNB011264217A CN1190449C (en) | 2001-08-07 | 2001-08-07 | Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1330089A true CN1330089A (en) | 2002-01-09 |
| CN1190449C CN1190449C (en) | 2005-02-23 |
Family
ID=4666439
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNB011264217A Expired - Lifetime CN1190449C (en) | 2001-08-07 | 2001-08-07 | Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1190449C (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1927898B (en) * | 2006-09-13 | 2010-07-14 | 上海氯碱化工股份有限公司 | Preparation method of low polymerization degree and high porosity resin |
| CN102453176A (en) * | 2010-10-22 | 2012-05-16 | 中国石油化工股份有限公司 | Preparation method of PVC (polrvinyl chloride) resin with high porosity and low film coverage rate |
-
2001
- 2001-08-07 CN CNB011264217A patent/CN1190449C/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1927898B (en) * | 2006-09-13 | 2010-07-14 | 上海氯碱化工股份有限公司 | Preparation method of low polymerization degree and high porosity resin |
| CN102453176A (en) * | 2010-10-22 | 2012-05-16 | 中国石油化工股份有限公司 | Preparation method of PVC (polrvinyl chloride) resin with high porosity and low film coverage rate |
Also Published As
| Publication number | Publication date |
|---|---|
| CN1190449C (en) | 2005-02-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1029618C (en) | Method for production of hydrophilic polymer | |
| CN1145673C (en) | Formaldehyde-free binder for mouldings | |
| CN1042434C (en) | Crosslinked methacrylic anhydride copolymers | |
| CN1072232C (en) | Method of producing oefin polymer graft copolymers | |
| CN1927898A (en) | Preparation method of low polymerization degree and high porosity resin | |
| CN105037626A (en) | Method for preparing big hole large particle diameter polymer microspheres | |
| CN1344750A (en) | Prep. of polyvinyl ester resin emulsion | |
| CN1317309C (en) | Process for the production of sap | |
| CN1275137A (en) | Method of production of particulate polymers | |
| CN1168750C (en) | Suspension polymerization process of preparing polyvinyl chloride resin with high molecular weight | |
| CN1190449C (en) | Application of novel dispersion system in preparing polyvinyl chloride resin dedicated for pipes with high apparent density | |
| JPH07179504A (en) | Fine particle polymer and its production | |
| CN1560094A (en) | Nano macromolecule microball of epoxy function type cross-linked nucleocapsid structure and preparation process thereof | |
| CN108892231B (en) | Method for manufacturing biological enhanced membrane reactor and application of reactor in coking wastewater treatment | |
| CA1335854C (en) | Production method of fine grain ice and dry clathrate water for manufacturing of concrete/mortar, a production method of concrete/mortar by using fine grain ice or dry clathrate water and concrete/mortar products manufactured by the production method of concrete/mortar | |
| CN86101462A (en) | Produce a kind of method of vinyl chloride resin | |
| CN109776873B (en) | Emulsion solvent volatilization method for preparing macroporous polymer microspheres | |
| CN1279068C (en) | Crosslinked core-shell structure nano-polymer microsphere and its preparation method | |
| CN1390865A (en) | Special resin for dulling polyvinyl chloride and its preparing process | |
| CN1631920A (en) | Process for preparing vinyl chloride/nano calcium carbonate in-situ polymerization resin | |
| CN1258544C (en) | Nano macromolecule microball of carboxy function type cross-linked nucleocapsid structure and preparation process thereof | |
| CN1560095A (en) | Nano macromolecule microball of carboxy function type cross-linked nucleocapsid structure and preparation process thereof | |
| CN109926026B (en) | Gel membrane for decolorizing ion exchange type printing and dyeing wastewater and preparation method thereof | |
| CN100344659C (en) | Preparation of water phase suspended swelling graft polypropylene | |
| CN1168749C (en) | Suspension polymerization process of preparing polyvinyl chloride resin for extruding to form hard building material product |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CX01 | Expiry of patent term |
Granted publication date: 20050223 |
|
| CX01 | Expiry of patent term |