GB2342653A - A method for preparing hydrophilic polymer - Google Patents
A method for preparing hydrophilic polymer Download PDFInfo
- Publication number
- GB2342653A GB2342653A GB9925429A GB9925429A GB2342653A GB 2342653 A GB2342653 A GB 2342653A GB 9925429 A GB9925429 A GB 9925429A GB 9925429 A GB9925429 A GB 9925429A GB 2342653 A GB2342653 A GB 2342653A
- Authority
- GB
- United Kingdom
- Prior art keywords
- particles
- substrate
- chamber
- polymer
- hydrophilic polymer
- 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.)
- Withdrawn
Links
- 238000000034 method Methods 0.000 title claims abstract description 10
- 229920001477 hydrophilic polymer Polymers 0.000 title claims abstract 4
- 239000002245 particle Substances 0.000 claims abstract description 20
- 229920000642 polymer Polymers 0.000 claims abstract description 10
- 239000000758 substrate Substances 0.000 claims abstract description 10
- 239000000178 monomer Substances 0.000 claims abstract description 8
- 230000001678 irradiating effect Effects 0.000 claims abstract description 4
- 238000005507 spraying Methods 0.000 claims abstract description 4
- 229920001577 copolymer Polymers 0.000 claims abstract description 3
- 238000009877 rendering Methods 0.000 claims abstract description 3
- 238000003860 storage Methods 0.000 abstract description 17
- 230000005855 radiation Effects 0.000 abstract description 3
- 239000004698 Polyethylene Substances 0.000 abstract description 2
- -1 polyethylene Polymers 0.000 abstract description 2
- 229920000573 polyethylene Polymers 0.000 abstract description 2
- 238000002360 preparation method Methods 0.000 abstract 1
- 239000000463 material Substances 0.000 description 29
- 239000007787 solid Substances 0.000 description 17
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 13
- 239000012530 fluid Substances 0.000 description 10
- 230000008014 freezing Effects 0.000 description 10
- 238000007710 freezing Methods 0.000 description 10
- 239000007788 liquid Substances 0.000 description 7
- 239000000725 suspension Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000002156 mixing Methods 0.000 description 4
- 239000002002 slurry Substances 0.000 description 4
- 230000036571 hydration Effects 0.000 description 3
- 238000006703 hydration reaction Methods 0.000 description 3
- 238000000926 separation method Methods 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 238000010257 thawing Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000012782 phase change material Substances 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 230000002441 reversible effect Effects 0.000 description 2
- 238000000518 rheometry Methods 0.000 description 2
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 description 1
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- WHNWPMSKXPGLAX-UHFFFAOYSA-N N-Vinyl-2-pyrrolidone Chemical compound C=CN1CCCC1=O WHNWPMSKXPGLAX-UHFFFAOYSA-N 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000011243 crosslinked material Substances 0.000 description 1
- 230000000994 depressogenic effect Effects 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 238000001879 gelation Methods 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 229920001480 hydrophilic copolymer Polymers 0.000 description 1
- 239000003999 initiator Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- PSGAAPLEWMOORI-PEINSRQWSA-N medroxyprogesterone acetate Chemical compound C([C@@]12C)CC(=O)C=C1[C@@H](C)C[C@@H]1[C@@H]2CC[C@]2(C)[C@@](OC(C)=O)(C(C)=O)CC[C@H]21 PSGAAPLEWMOORI-PEINSRQWSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000012266 salt solution Substances 0.000 description 1
- 238000013341 scale-up Methods 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- SRRKNRDXURUMPP-UHFFFAOYSA-N sodium disulfide Chemical compound [Na+].[Na+].[S-][S-] SRRKNRDXURUMPP-UHFFFAOYSA-N 0.000 description 1
- HYHCSLBZRBJJCH-UHFFFAOYSA-M sodium hydrosulfide Chemical compound [Na+].[SH-] HYHCSLBZRBJJCH-UHFFFAOYSA-M 0.000 description 1
- 229910052979 sodium sulfide Inorganic materials 0.000 description 1
- GRVFOGOEDUUMBP-UHFFFAOYSA-N sodium sulfide (anhydrous) Chemical compound [Na+].[Na+].[S-2] GRVFOGOEDUUMBP-UHFFFAOYSA-N 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
- 238000013517 stratification Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
- A61Q19/00—Preparations for care of the skin
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
- A61K8/00—Cosmetics or similar toiletry preparations
- A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
- A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
- A61K8/81—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
- A61K8/817—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by a single or double bond to nitrogen or by a heterocyclic ring containing nitrogen; Compositions or derivatives of such polymers, e.g. vinylimidazol, vinylcaprolactame, allylamines (Polyquaternium 6)
- A61K8/8182—Copolymers of vinyl-pyrrolidones. Compositions of derivatives of such polymers
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
- B01J19/122—Incoherent waves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/08—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor
- B01J19/12—Processes employing the direct application of electric or wave energy, or particle radiation; Apparatus therefor employing electromagnetic waves
- B01J19/122—Incoherent waves
- B01J19/123—Ultraviolet light
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/18—Stationary reactors having moving elements inside
- B01J19/22—Stationary reactors having moving elements inside in the form of endless belts
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F2/00—Processes of polymerisation
- C08F2/46—Polymerisation initiated by wave energy or particle radiation
- C08F2/48—Polymerisation initiated by wave energy or particle radiation by ultraviolet or visible light
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- Electromagnetism (AREA)
- Toxicology (AREA)
- Physics & Mathematics (AREA)
- Veterinary Medicine (AREA)
- Public Health (AREA)
- Medicinal Chemistry (AREA)
- Epidemiology (AREA)
- Birds (AREA)
- Polymers & Plastics (AREA)
- Dermatology (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Abstract
A method for preparing particles of a hydrophilic polymer, comprises spraying monomer onto a moving substrate 21, irradiating the monomer to form a continuous sheet of polymer 23 on the substrate, stripping the sheet off the substrate 25 and rendering the sheet into particles. The hydrophilic polymer may be an acrylonitrile-vinylpyrrolidone copolymer. The substrate 21 may be a polyethylene belt. The irradiating radiation may be UV light. The method may be used to prepare particles for thermal storage or for non-ophthalmic medical preparations e.g in skin care and wound care.
Description
APPARATUS AND MATERIALS FOR THERMAL STORAGE
Field of the Invention
This invention relates to apparatus and materials for use in thermal storage.
Background of the Invention
GB-A-1587725 describes a thermal store, in which heat is transferred in a fluid between a mobile suspension of suspended particles comprising a material that undergoes a reversible phase change with release or absorption of heat.
The suspending fluid may be a gas or liquid. For low temperature storage, it is proposed that the fluid may be an oil, the particles a hydrophilic material, and the phase-change substance water. It is suggested that the concentration of particles in the suspension should be as high as possible, to maximise the effect obtained by the phase change, but that a high concentration may present difficulties, in maintaining the suspension and in pumping it.
The specific apparatus that is disclosed in GB-A1587725, comprises a storage vessel filled with a hydrocarbon in which particles of an acrylonitrilevinylpyrrolidone (AN-VP) polymer, hydrated with water, are suspended. In use, the suspension is circulated, using a pump, from the top of the vessel to its base. A heat exchanger in the vessel is operated to cool the water in the hydrated polymer; the water freezes and its latent heat of fusion is extracted. The stored matter can then be used to cool water or air in a circuit passing through the vessel and to an external output, e. g. the air in an air conditioner.
The theory underlying the disclosure of GB-A-1587725 is correct, but its practical expression has been limited.
This may be due in part to the difficulty, mentioned above, of maintaining a sufficiently high concentration of suspended particles. Economical production of suitable materials may also have been a problem.
Summary of the Invention
According to a first aspect of the present invention, a thermal storage system comprises first and second heat exchangers connected by a closed loop containing a fluid medium in which are suspended particles comprising a material that undergoes a reversible phase change on thermal input/output, the system comprising also a chamber containing the fluid and a relatively high particle concentration, means for metering the solids from the chamber into the loop, and means for returning the solids from the loop to the chamber.
This storage/metering device avoids the difficulty of simultaneously storing and pumping a suspension having the same solids concentration for each purpose when ideally the storage function requires high solids concentrations (e. g. up to 85% by volume) while the circulation application requires a lower solids concentration (e. g. from 5 or 10%, up to 30% by volume).
According to a second aspect of this invention, the hydrophilic material in a thermal store is designed to have the maximum possible water content. It has been found that a suitable material can be made having a water content of 85 to 98% water by wet weight, e. g. by radiation polymerisation of a monomer water solution, so producing a pre-hydrated material. The resulting polymer gel is very soft and elastic, and is well suited to providing a packing round the heat exchanger/evaporator of, say, a domestic refrigerator. It is suitable either for slow speed circulation or for static use when it operates to prevent density-induced stratification of the phase-change material (water) during freezing and thawing. Non-uniform freezing and thawing, a process which reduces the efficiency of conventional uncirculated water/ice stores, is thus reduced or eliminated.
According to a third aspect of this invention, the same or different hydrophilic material, which is suitable for use in a circulating pumpable thermal storage system, is made by spraying monomer onto a moving substrate, irradiating the monomer to form a continuous sheet of polymer on the substrate, stripping the sheet of the substrate and rendering the sheet into particles by, for example, grinding.
Description of the Invention
The principles underlying the present invention, and materials that may be used, as medium, particulate matrix and phase-change material, are described in GB-A-1587725, the relevant content of which is incorporated herein by reference. By contrast to the disclosure therein, the present invention provides a relatively low concentration of suspended material in circulation and a relatively high concentration in the specified chamber. The pipes providing the specified closed loop may provide the major volume of the system, and moving suspended particles through the loop will be difficult, if they are present in high concentration; that problem is overcome by means of the present invention.
According to the present invention, particles in circulation are introduced as desired, by metering means such as an auger which may also serve to circulate the relatively concentrated suspension in the store. Such means, preferably together with valves which control the pressure differential across the mixing chamber, allows control of the system, depending on the rheology of the particle-fluid system. Some factors which apply are (by way of illustration only): (i) Control of hydration to achieve partial hydration: partially-hydrated hydrophilic material placed in oil and sealed into the apparatus remains partially hydrated and free from agglomeration or clogging which may occur if the material is fully hydrated, due to the formation of ice"bridges"between the particles.
(ii) Choice of hydrophilic material to control spread of freezing temperature: it is known that certain hydrophilic materials, e. g. acrylonitrile-vinylpyrrolidone copolymers, exhibit the property of suppressing freezing until a temperature below 0 C has been reached. This effect can be controlled by the choice of comonomers used in the polymerisation of the hydrophilic copolymer, and by the control of the ultimate water uptake of the polymer when fully hydrated. Suitable choice of material and freezing temperature can be used to optimise the efficiency of a cold storage system and match the cold store to the application and to the type and performance specification of a refrigerator heat pump.
(iii) Choice of hydration solutions with non-zero freezing/thawing characteristics: hydrophilic materials have been shown to be hydratable in a number of salt solutions, including NaCl and CaClz, which depress the freezing temperature of aqueous systems, and it has been established that the effective freezing temperature of the hydrophilic material hydrated in the solution is also depressed. This is a second way in which the storage temperature can be matched to the application and to the properties of the heat pump. It has also been shown that a number of materials which form aqueous solutions increase the freezing temperature, e. g. to above 0 C. An example of such a material is sodium disulphide (20% Na2S in water has a freezing temperature of 21 C) or sodium hydrosulphide (NaSH). This enables the storage temperature to be above 0 C.
In a particularly simple embodiment of the invention, particles in circulation are distributed between return to the chamber and further circulation, by density separation.
For this purpose, the closed loop suitably has an inlet to, and an outlet from, the upper part of the chamber.
Material to be recirculated is suitably introduced into the loop from the lower end of the chamber. The distribution effect may be enhanced by the provision of a cyclone, or a suitable impeller having flexible vanes. A combined liquid/gas entrainment pump may be used, for circulation.
The use of, say, a liquid cyclone, to actively separate the hydrated hydrophilic materials from the fluid rather than rely upon density separation, enables the system to service a local circulation system operating at low solids concentrations, e. g. 10 to 30%, while allowing the storage chamber to operate with a higher solids concentration, for example of more than 30%, e. g. at least 40%, say 50 to 80% solids by volume. Further, it is possible to have rheological control of the support liquid, by the inclusion of gelation agents, e. g. Cab-O-Sil, to control flow and settlement, by controlling the yield stress in the fluid.
The present invention will now be described by way of example only with reference to the accompanying drawings, in which:
Figure 1 is a schematic view of a thermal storage system embodying the first aspect of this invention;
Figure 2 is a schematic view of a preferred embodiment of part of a thermal storage system ; and
Figure 3 is a schematic view of apparatus for use in the third aspect of the invention.
Figure 1 shows a central chamber 10, having a neck 11 at its lower end, in which a rotatable auger 12 (shown in dotted lines) is disposed. An (optional) liquid cyclone 13 is also shown, near the top of the chamber. The chamber 10 is in communication with a closed loop 14 having a point of connection 15 to a pump (not shown). The loop passes through first and second heat exchangers 16a, 16b shown respectively on the left and right-hand sides of the loop.
In use of the device shown in Fig. 1, an oil medium is used, by way of example, in the loop. Depending on the input and output temperatures, the oil medium may contain 30% solids, in that arm of the loop in heat exchanger 16a, and a low concentration of solids, i. e. nearly clear oil, in the other arm, in heat exchanger 16b. A solids concentration gradient or the cyclone 13, if present, causes a predominant flow as indicated by arrows, and thus provides a greater concentration of particles in the chamber 10 than in circulation in the loop 14.
The circulating store illustrated in Fig. 2 has many of the same components, with the same reference numerals, as the embodiment of Fig. 1. Slurry returns to the character 10 at 14a, and clear fluid passes out to a primary circulating pump (not shown) at 14b. Clear fluid returns via a valve 17a, and pumped slurry, at a controllable solids concentration, passes through a valve 17b. The rotatable control device 12 is positioned in what is effectively a missing chamber 18. The chamber 10 includes supply devices 19.
The apparatus of Fig. 2 has been operated, using a primary chamber whose right cylindrical part is 300 m in diameter and 900 pm high. The control device is rotatable at 1-10 Hz.
In experiments, it was found that the"transport" section of the apparatus could be controlled within the range 0-40% by adjusting the rate of rotation of the metering screw. The slurry then passed through the external circuit and returned to the top of the storage tank where the solids were separated from the oil, and the cycle was repeated. A non-specialist pump could be used to provide the primary circulation effect in the external circuit, and the effective energy content of the slurry could be controlled by changing the concentration of solids. The system should be relatively easy to scale up to commercial size because of the independence of the storage function (operating at a high concentration of material) from the rheology of the pumped mixture in the external circulation system.
It was found that the addition of two valves (17a and 17b) adjacent to the mixing chamber provided an additional "rapid response"control of the mixing process, by allowing the pressure difference across the mixing chamber to be varied and thus the concentration of solids in the circulating flow to be controlled, independently of the rate of rotation of the screw.
Using this apparatus, it was found that the store could be maintained at an effective solids concentration of > 50% while the circulation system operated at 0-40%, providing separate thermal and rheological control of the processes at each stage. In a commercial device, it is probable that some positive means of separating the solids from the oil on the return limb may be desirable, and a form of liquid cyclone is recommended for this purpose so that the range of flow rates used in the external circuit can be increased without detriment to the separation process.
The particles pass downwardly through the lower neck of the chamber, and are urged through the neck by the auger, at a rate controlled by the shape and rate of rotation of the auger and any applied pressure differential. It is desirable that the particles should be of a high tear strength material. If a hydrophilic material is used, AN-VP is preferred.
Figure 3 illustrates how suitable hydrophilic materials can be prepared cheaply on a continuous basis.
Liquid monomer is sprayed by means (not shown) at 20, in the direction indicated, onto a belt 21, e. g. of polyethylene or PTFE, mounted on rollers 22a, 22b driven by means (not shown) in the direction indicated. The spraying may be conducted, if necessary, in a controlled (N2) environment. A layer 23 of material is formed on the belt, and is irradiated by means of a light source represented by hoods 24. If W radiation is employed, e. g. Hg discharge lamps, then a W-sensitive initiator such as DMPA is used.
The resulting polymer is removed continuously from the belt using a stripping blade 25. It can then be ground to size, for use.
In experiments using the apparatus shown in Fig. 3, a rough strip of polymer, 1-2 um thick was obtained. This was well suited to grinding in a hammer mill.
This process has potential for the production of hydrophilic materials for non-ophthalmic medical applications, e. g. in skin care and wound care. In particular, a high-strength, high purity cross-linked material, e. g. based on acrylonitrile and vinylpyrrolidone can be produced, in powder form.
Claims (3)
- CLAIMS 1. A method for preparing particles of a hydrophilic polymer, which comprises spraying monomer onto a moving substrate, irradiating the monomer to form a continuous sheet of polymer on the substrate, stripping the sheet off the substrate, and rendering the sheet into particles.
- 2. A method according to claim 1, wherein the polymer is an acrylonitrile-vinylpyrrolidone copolymer.
- 3. A method according to claim 1, substantially as herein described with reference to the accompanying drawing.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GBGB9606872.1A GB9606872D0 (en) | 1996-04-01 | 1996-04-01 | Apparatus and materials for thermal storage |
GB9706520A GB2312500B (en) | 1996-04-01 | 1997-04-01 | Apparatus and materials for thermal storage |
Publications (2)
Publication Number | Publication Date |
---|---|
GB9925429D0 GB9925429D0 (en) | 1999-12-29 |
GB2342653A true GB2342653A (en) | 2000-04-19 |
Family
ID=26309041
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB9925429A Withdrawn GB2342653A (en) | 1996-04-01 | 1997-04-01 | A method for preparing hydrophilic polymer |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB2342653A (en) |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3912607A (en) * | 1969-10-22 | 1975-10-14 | Rhone Progil | Process for obtaining high molecular weight water-soluble acrylic polymers and copolymers using radiation |
US4178221A (en) * | 1976-04-14 | 1979-12-11 | Rhone-Poulenc Industries | Process for the preparation of water-soluble acrylic polymers by photopolymerization |
EP0036819A2 (en) * | 1980-03-24 | 1981-09-30 | Calgon Corporation | Continuous polymerization process for preparing polymers and copolymers of ethylenically unsaturated water-soluble monomers |
US4612336A (en) * | 1984-12-27 | 1986-09-16 | Dai-Ichi Kogyo Seiyaku Co., Ltd. | Process for preparing water-soluble acrylic polymers by irradiating aqueous monomer solutions containing a surfactant |
EP0197423A1 (en) * | 1985-03-27 | 1986-10-15 | Mitsubishi Rayon Co., Ltd. | Method of continuously photopolymerizing water soluble vinyl monomer |
-
1997
- 1997-04-01 GB GB9925429A patent/GB2342653A/en not_active Withdrawn
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3912607A (en) * | 1969-10-22 | 1975-10-14 | Rhone Progil | Process for obtaining high molecular weight water-soluble acrylic polymers and copolymers using radiation |
US4178221A (en) * | 1976-04-14 | 1979-12-11 | Rhone-Poulenc Industries | Process for the preparation of water-soluble acrylic polymers by photopolymerization |
EP0036819A2 (en) * | 1980-03-24 | 1981-09-30 | Calgon Corporation | Continuous polymerization process for preparing polymers and copolymers of ethylenically unsaturated water-soluble monomers |
US4612336A (en) * | 1984-12-27 | 1986-09-16 | Dai-Ichi Kogyo Seiyaku Co., Ltd. | Process for preparing water-soluble acrylic polymers by irradiating aqueous monomer solutions containing a surfactant |
EP0197423A1 (en) * | 1985-03-27 | 1986-10-15 | Mitsubishi Rayon Co., Ltd. | Method of continuously photopolymerizing water soluble vinyl monomer |
Non-Patent Citations (1)
Title |
---|
Online (JAPIO) abstract for JP040168102 * |
Also Published As
Publication number | Publication date |
---|---|
GB9925429D0 (en) | 1999-12-29 |
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Legal Events
Date | Code | Title | Description |
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WAP | Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1) |