CA2137154A1 - Elastosols, preparation, use and products thereof - Google Patents
Elastosols, preparation, use and products thereofInfo
- Publication number
- CA2137154A1 CA2137154A1 CA002137154A CA2137154A CA2137154A1 CA 2137154 A1 CA2137154 A1 CA 2137154A1 CA 002137154 A CA002137154 A CA 002137154A CA 2137154 A CA2137154 A CA 2137154A CA 2137154 A1 CA2137154 A1 CA 2137154A1
- Authority
- CA
- Canada
- Prior art keywords
- elastosol
- block copolymer
- weight
- monovinyl aromatic
- micron
- 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.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K5/00—Use of organic ingredients
- C08K5/0008—Organic ingredients according to more than one of the "one dot" groups of C08K5/01 - C08K5/59
- C08K5/0016—Plasticisers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L53/00—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
- C08L53/02—Compositions of block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers of vinyl-aromatic monomers and conjugated dienes
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
- C09D153/00—Coating compositions based on block copolymers containing at least one sequence of a polymer obtained by reactions only involving carbon-to-carbon unsaturated bonds; Coating compositions based on derivatives of such polymers
- C09D153/02—Vinyl aromatic monomers and conjugated dienes
Abstract
An elastosol is provided comprising:(a) a finely powdered, linear or branched block copolymer having a particle size of 800 micron or less, comprising at least one polymer block (A) derived predominantly from a monovinyl aromatic compound and at least one, optionally hydrogenated, polymer block (B) derived predominantly from a conjugated diene, wherein the content of monovinyl aromatic compound is at least 40 % by weight based on the weight of the block copolymer, and (b) a rubber compati-ble liquid plasticizer, the weight ratio (a)/(b) being in the range of from 0.1 to 10. Furthermore, there is provided a process for the preparation of an elastosol as well as a process for the preparation of a homogeneous rubbery product derived from said elasto-sol.
Description
~ WO 93/25614 21 3 715 l~ PC~r/EP93/01408 ELA~S, pREpARA'l~(l~ E'C)R
The present invention relates to elastosols, to a process forthe preparation of such elastosols, to a process for use of these elastosols and to products derived from them.
With the term "elastosols" as used throughout this S specification is meant dispersions of very fine elastomeric block copolymer particles in liquid organic media, or more specifically, in rubber compatible liquid plasticizers.
At present polyvinylchloride plastisols, i.e. dispersions of very fine PVC particles in liquid organic media, are widely used for a variety of applications, such as in the preparation of bottle cap seals, conveyor belts, carpet backing and wall- and floor-coverings. In other applications PVC plastisols are processed by means of dipping, such as in the case of industrial gloves, surgical gloves, shoes, boots and coated wire products. The shaping of products by means of roto-casting or moulding, which is the reverse of dipping, is also a widely used technique. The latter method is particularly suited for the production of hollow goods, such as certain toys (balls, dolls and the like). Since there is an increasing ~P~-nd for environmental friendly products, PVC
cont~ining compositions are the subject of many discussions due to the presence of the environmentally charging element chlorine in PVC. It will be appreciated that upon disposal of PVC cont~ining products, e.g. by incineration, toxic compounds cont~ining chlorine may be released into the environment. Therefore, extensive research effort is put in by industry to find halogen-free alternatives for PVC. However, a significant problem is to find such alternatives, which provide at least the same processing and product characteristics as the presently applied PVC plastisols. One of the W O 93/25614 ` ~ ~ 3 7 ~ ~ ~ P ~ /EP93/01408 main advantages of using PVC plastisols namely, is their ability to be processed by the above mentioned inexpensive processing techniques, such as spreading, moulding or roto-casting and dipping, followed by zero-shear fusion of the plastisol to form the desired product. These techniques are much more flexible and provlde higher production speeds than the conventional th~_ ~plastics processing techniques like extrusion and in~ection moulding. Up to now not any satisfactory halogen-free alternative for PVC plastisols has been found, which can be prepared and processed according to said advantageous plastisol processing techniques. Moreover, as in the present situation these techniques are widely used in the PVC-plastisol industry, it is by far preferred to develop halogen-free alternatives which can be processed (and prepared) using the existing equipment in order to keep the investment costs as low as possible.
It will be appreciated that it is a main object of the present invention to provide a halogen-free PVC alternative in the form of a dispersion and more particularly in the form of an elastosol, which can be processed by means of the presently applied plastisol techniques.
~rom CAnA~iAn Patent No. l,132,283 a composition is known contAinine a highly oil extended conjugated diene/vinyl aromatic radial teleblock copolymer. Said composition is prepared by dissolving the block copolymer in the oil under shear conditions, e.g. by stirring, and at an elevated temperature of 120 C to 205 C. The radial block copolymer contains 50-95% by weight of the co~ugated diene and 5-50% by weight of the monovinyl aromatic compound. Due to the relatively higher content of con~ugated diene in comparison with the monovinyl aromatic compound, the radial block copolymer is highly elastic. The oil to be used preferably is a naphtenic oil as the bleeding-out of oil is most likely to occur if paraffinic oil is used. The weight ratio of polymer to oil may vary from 0.5 to O.l, which implies that oil is always present in larger amounts than the polymer. As a result, the composition is t rather soft and the complete absence of bleeding-out of oil is ~ W O 93/tS614 213 7 ~ ~ ~ PC~r/EP93/01408 difficult to realize. Moreover, during the preparation of the composition, the radial teleblock copolymer must be dissolved at an elevated temperature in order to obtain a homogeneous blend eventually. The processing of such compositions prepared by this melt technique is rather difficult, as shaped articles or homogeneous films can only be prepared starting from a hot mixture.
It will be appreciated that storage of the homogeneous blend is in fact impossible as homogeneity is only reached at elevated temperatures and after cooling the resulting product is too stiff to be processed any further. So after its preparation, the homogeneous blend immediately must be processed.
Hence, it would be advantageous to provide an elastosol, which is stable at room temperature and which consequently can be prepared, handled and stored at relatively low temperatures.
Heating the elastosol is carried out only after the elastosol has been brought in its desired end shape.
It is therefore another object of the present invention to provide a process for the preparation of an elastosol, which process can be carried out at relatively low temperature, in order to obtain an elastosol which is stable at room temperature.
A further object of the present invention is to provide a process for the preparation of a product obtainable from said elastosol via a phase inversion process.
Accordingly, the invention relates to an elastosol comprising:
(a) a finely powdered, linear or branched block copolymer having a particle size of 800 micron or less, comprising at least one polymer block A derived predominantly from a monovinyl aromatic compound and at least one, optionally hydrogenated, polymer block B derived pre~o~inAntly from a conjugated diene, wherein the content of monovinyl aromatic compound is at least 40% by weight based on the weight of the block copolymer, and (b) a rubber compatible liquid plasticizer, the weight ratio (a)/(b) being in the range of from O.l to lO.
~ith the terms "derived pre~omin~ntly from a monovinyl aromatic compound" and "derived pred. In~ntly from a conjugated , W O 93/25614 2 ~ ~ 7 1~ ~ PC~r/EP93/01408 ~
diene" as used throughout the present specification in connection with the composition of the polymer blocks of the block copolymer, are meant that respectively the monovinyl aromatic compound and the con~ugated diene are present in the polymer block under consideration in an amount of at least 80~ by weight based on said polymer block. The r~ o;nin~ 20% by weight or essentially less consists of conjugated diene monomer in the case of a monovinyl aromatic polymer block and of monovinyl aromatic monomer in the case of a conjugated diene polymer block. Preferably, these (co)monomers are similar to those actually incorporated in the poly(conjugated diene) and poly(monovinyl aromatic) blocks.
From British Patent Specification No. l,125,499 a closure for containers is known comprising a shell adapted for ?~hAn1cal engagement with the container and a liner in said shell for e~g~ ng and sealing the container. This liner is transparent and comprises a triblock copolymer of general configuration A-B-A with A being a poly(monovinyl aromatic) block and B an optionally hydrogenated poly(con~ugated diene) block and per 10~ parts by weight of said block copolymer 20 to lO0 parts by weight of a mineral oil extender. The composition must be soft and elastic in order to be able to actually engage and seal a container and therefore the content of monovinyl aromatic compound can not be too high. Furthermore, the composition is prepared by ;~ing the block copolymer and the oil, followed by extrusion of the resulting mixture. Hence, a shear requiring technique, such as extrusion, must be applied for processing the block copolymer/oil blend according to said British patent specification. Such techniques are undesired because of the relatively expensive equipment necessary.
According to the present invention this disadvantage is overcome by using an elastosol, as a result of which processing can take place via plastisol techniques which do not require shear.
From U.S. patent no. 4,331,581 a process for the preparation of an elastosol paste is known using three different organic solvents, such as cyclohexane and toluene (first solvent), methyl ethyl ketone (second solvent) and isopropyl alcohol (third W O 93/25614 ~ i 3 7 ~ ~ ~ PC~r/~Y3/Ul4M
solvent). In the final step of the disclosed process, the elastosol paste precipitates from the last added, i.e. third, solvent.
Consequently, the precipitated elastosol paste still contains a subst~n~i~l amount of solvent, which requires an extra process step for removing solvent, e.g. by evaporation. Such a method requiring the use of organic solvent is undesired for environmental reasons and moreover, in the presently applied plastisol techniques organic solvents are not used at all, thereby avoiding said extra solvent removal step. Therefore, the present invention provides processes for preparing elastosols and pastes derived therefrom without using any organic solvents.
It will be appreciated that the size of the block copolymer particles is very important. Small particles are necessary for obt~ining a stable dispersion in the plasticizer. Moreover, if the block copolymer particles are too large, it is not possible to transfer the dispersion of block copolymer particles in the rubber compatible plasticizer into a homogeneous product. In general, a particle size of 800 micron or less will suffice, whereas a particle size of 200 micron or less is preferred. A particle size of 100 micron or less is most preferred. The lower limit of the particle size preferably is as close to zero as possible and is determined by the technique used for obt~jning the small block copolymer particles. In general, a lower limit of 1 micron, more suitably 10 micron, will suffice for the purpose of the present invention.
In a preferred embodiment of the present invention, the monovinyl aromatic content is in the range of from 50 to 95% by weight, whereas linear block copolymers comprising two poly(monovinyl aromatic) endblocks A and one poly(conjugated diene) block B are also preferred. The polymer blocks B may be either unhydrogenated or hydrogenated to any desired extent.
The poly(monovinyl aromatic) block A can be derived from styrene, ~-methylstyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene or mixtures thereof, of which styrene is the preferred monomer. The apparent molecular .
W O 93/25614 ~ ~ 3 71 ~ i~ P ~ /EP93/01408 weight of block A, as determined by gel permeation chromatography using polystyrene standards, can vary within wide ranges. In general, block A may have any apparent molecular weight in the range of from 5,000 to 150,000 and preferably between 8,000 and 70,000.
The poly(con~ugated diene) block B can be derived from 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene or mixtures thereof, of which 1,3-butadiene and isoprene are the most preferred monomers. The number average molecular weight of the rubbery block B is primarily determined by the amount of plasticizer to be absorbed during phase-inversion from elastosol to final product. In general, any number average molecular weight within the range of from 5,000 to 300,000 may be suitable, whereas a number average molecular weight in the range of from 10,000 to 150,000 is preferred.
Basically, the rubber compatible liquid plasticizer has two functions. Firstly, it embodies a liquid medium which enables the block copolymer particles to disperse, thus forming the elastosol according to the invention. This elastosol consists of three separate phases: a first phase formed by the "hard" poly(monovinyl aromatic) do~inc in the block copolymer particles, a second phase formed by the "soft" poly(conjugated diene) domains of said block copolymer particles and a third phase formed by the rubber compatible liquid plasticizer.
The second function of the plasticizer is that upon heating to a temperature above the glass transition temperature of the poly(monovinyl aromatic) d sinC it extends the rubber phase, i.e.
the poly(con~ugated diene) do oinc. After the plasticizer has been absorbed completely by the rubber phase, this rubber phase will have swollen to such an extent that it will now form the continuous phase. At temperatures above the glass transition temperature Of the poly(monovinyl aromatic) domains, said domains will completely soften and upon cooling rearrange into new, interconnecting . 35 poly(monovinyl aromatic) ~- oinc. Hence, a phase inversion has ~ W O 93/25614 2 1 3 7 1 ~ i~ PC~r/EP93/01408 occurred, as the original 2+1 phase-situation has been transformed into a 2 phase-situation: one phase consisting of the newly formed poly(monovinyl aromatic) dom~inc and one phase formed by the plasticizer extended rubber phase. This 2 phase-situation is a homogeneous extended rubber, which remains stable after cooling down to e.g. room temperature.
The weight ratio between the block copolymer and the plasticizer is also very important. If this ratio is too high, i.e.
higher than 10, the viscosity of the obtained elastosol will be too high. However, a too low ratio, i.e. lower than 0.1, will result in an extended rubber being very weak at room temperature, because the plasticizer will not be completely absorbed by the rubber phase. As a result, bleeding out of the plasticizer is likely to occur. In a preferred embodiment said weight ratio lies within the range of from 0.4 to 3.
The plasticizer to be used may be any known rubber compatible liquid plasticizer, such as a naphthenic oil, a paraffinic oil, an aromatic oil or a mixture thereof, as well as a low molecular weight polyisobutylene or polybutylene. A paraffinic oil, however, is preferred.
The elastosol according to the invention can be prepared by any suitable process for preparing dispersions with the proviso that the finally formed block copolymer particles are small enough to be dispersed in an oil. The block copolymer may be produced by any well known block polymerization or copolymerization process including the well known sequential addition of monomer techniques, incremental addition of monomer technique or couFling technique as illustrated in, for example, U.S. patent specifications nos.
The present invention relates to elastosols, to a process forthe preparation of such elastosols, to a process for use of these elastosols and to products derived from them.
With the term "elastosols" as used throughout this S specification is meant dispersions of very fine elastomeric block copolymer particles in liquid organic media, or more specifically, in rubber compatible liquid plasticizers.
At present polyvinylchloride plastisols, i.e. dispersions of very fine PVC particles in liquid organic media, are widely used for a variety of applications, such as in the preparation of bottle cap seals, conveyor belts, carpet backing and wall- and floor-coverings. In other applications PVC plastisols are processed by means of dipping, such as in the case of industrial gloves, surgical gloves, shoes, boots and coated wire products. The shaping of products by means of roto-casting or moulding, which is the reverse of dipping, is also a widely used technique. The latter method is particularly suited for the production of hollow goods, such as certain toys (balls, dolls and the like). Since there is an increasing ~P~-nd for environmental friendly products, PVC
cont~ining compositions are the subject of many discussions due to the presence of the environmentally charging element chlorine in PVC. It will be appreciated that upon disposal of PVC cont~ining products, e.g. by incineration, toxic compounds cont~ining chlorine may be released into the environment. Therefore, extensive research effort is put in by industry to find halogen-free alternatives for PVC. However, a significant problem is to find such alternatives, which provide at least the same processing and product characteristics as the presently applied PVC plastisols. One of the W O 93/25614 ` ~ ~ 3 7 ~ ~ ~ P ~ /EP93/01408 main advantages of using PVC plastisols namely, is their ability to be processed by the above mentioned inexpensive processing techniques, such as spreading, moulding or roto-casting and dipping, followed by zero-shear fusion of the plastisol to form the desired product. These techniques are much more flexible and provlde higher production speeds than the conventional th~_ ~plastics processing techniques like extrusion and in~ection moulding. Up to now not any satisfactory halogen-free alternative for PVC plastisols has been found, which can be prepared and processed according to said advantageous plastisol processing techniques. Moreover, as in the present situation these techniques are widely used in the PVC-plastisol industry, it is by far preferred to develop halogen-free alternatives which can be processed (and prepared) using the existing equipment in order to keep the investment costs as low as possible.
It will be appreciated that it is a main object of the present invention to provide a halogen-free PVC alternative in the form of a dispersion and more particularly in the form of an elastosol, which can be processed by means of the presently applied plastisol techniques.
~rom CAnA~iAn Patent No. l,132,283 a composition is known contAinine a highly oil extended conjugated diene/vinyl aromatic radial teleblock copolymer. Said composition is prepared by dissolving the block copolymer in the oil under shear conditions, e.g. by stirring, and at an elevated temperature of 120 C to 205 C. The radial block copolymer contains 50-95% by weight of the co~ugated diene and 5-50% by weight of the monovinyl aromatic compound. Due to the relatively higher content of con~ugated diene in comparison with the monovinyl aromatic compound, the radial block copolymer is highly elastic. The oil to be used preferably is a naphtenic oil as the bleeding-out of oil is most likely to occur if paraffinic oil is used. The weight ratio of polymer to oil may vary from 0.5 to O.l, which implies that oil is always present in larger amounts than the polymer. As a result, the composition is t rather soft and the complete absence of bleeding-out of oil is ~ W O 93/tS614 213 7 ~ ~ ~ PC~r/EP93/01408 difficult to realize. Moreover, during the preparation of the composition, the radial teleblock copolymer must be dissolved at an elevated temperature in order to obtain a homogeneous blend eventually. The processing of such compositions prepared by this melt technique is rather difficult, as shaped articles or homogeneous films can only be prepared starting from a hot mixture.
It will be appreciated that storage of the homogeneous blend is in fact impossible as homogeneity is only reached at elevated temperatures and after cooling the resulting product is too stiff to be processed any further. So after its preparation, the homogeneous blend immediately must be processed.
Hence, it would be advantageous to provide an elastosol, which is stable at room temperature and which consequently can be prepared, handled and stored at relatively low temperatures.
Heating the elastosol is carried out only after the elastosol has been brought in its desired end shape.
It is therefore another object of the present invention to provide a process for the preparation of an elastosol, which process can be carried out at relatively low temperature, in order to obtain an elastosol which is stable at room temperature.
A further object of the present invention is to provide a process for the preparation of a product obtainable from said elastosol via a phase inversion process.
Accordingly, the invention relates to an elastosol comprising:
(a) a finely powdered, linear or branched block copolymer having a particle size of 800 micron or less, comprising at least one polymer block A derived predominantly from a monovinyl aromatic compound and at least one, optionally hydrogenated, polymer block B derived pre~o~inAntly from a conjugated diene, wherein the content of monovinyl aromatic compound is at least 40% by weight based on the weight of the block copolymer, and (b) a rubber compatible liquid plasticizer, the weight ratio (a)/(b) being in the range of from O.l to lO.
~ith the terms "derived pre~omin~ntly from a monovinyl aromatic compound" and "derived pred. In~ntly from a conjugated , W O 93/25614 2 ~ ~ 7 1~ ~ PC~r/EP93/01408 ~
diene" as used throughout the present specification in connection with the composition of the polymer blocks of the block copolymer, are meant that respectively the monovinyl aromatic compound and the con~ugated diene are present in the polymer block under consideration in an amount of at least 80~ by weight based on said polymer block. The r~ o;nin~ 20% by weight or essentially less consists of conjugated diene monomer in the case of a monovinyl aromatic polymer block and of monovinyl aromatic monomer in the case of a conjugated diene polymer block. Preferably, these (co)monomers are similar to those actually incorporated in the poly(conjugated diene) and poly(monovinyl aromatic) blocks.
From British Patent Specification No. l,125,499 a closure for containers is known comprising a shell adapted for ?~hAn1cal engagement with the container and a liner in said shell for e~g~ ng and sealing the container. This liner is transparent and comprises a triblock copolymer of general configuration A-B-A with A being a poly(monovinyl aromatic) block and B an optionally hydrogenated poly(con~ugated diene) block and per 10~ parts by weight of said block copolymer 20 to lO0 parts by weight of a mineral oil extender. The composition must be soft and elastic in order to be able to actually engage and seal a container and therefore the content of monovinyl aromatic compound can not be too high. Furthermore, the composition is prepared by ;~ing the block copolymer and the oil, followed by extrusion of the resulting mixture. Hence, a shear requiring technique, such as extrusion, must be applied for processing the block copolymer/oil blend according to said British patent specification. Such techniques are undesired because of the relatively expensive equipment necessary.
According to the present invention this disadvantage is overcome by using an elastosol, as a result of which processing can take place via plastisol techniques which do not require shear.
From U.S. patent no. 4,331,581 a process for the preparation of an elastosol paste is known using three different organic solvents, such as cyclohexane and toluene (first solvent), methyl ethyl ketone (second solvent) and isopropyl alcohol (third W O 93/25614 ~ i 3 7 ~ ~ ~ PC~r/~Y3/Ul4M
solvent). In the final step of the disclosed process, the elastosol paste precipitates from the last added, i.e. third, solvent.
Consequently, the precipitated elastosol paste still contains a subst~n~i~l amount of solvent, which requires an extra process step for removing solvent, e.g. by evaporation. Such a method requiring the use of organic solvent is undesired for environmental reasons and moreover, in the presently applied plastisol techniques organic solvents are not used at all, thereby avoiding said extra solvent removal step. Therefore, the present invention provides processes for preparing elastosols and pastes derived therefrom without using any organic solvents.
It will be appreciated that the size of the block copolymer particles is very important. Small particles are necessary for obt~ining a stable dispersion in the plasticizer. Moreover, if the block copolymer particles are too large, it is not possible to transfer the dispersion of block copolymer particles in the rubber compatible plasticizer into a homogeneous product. In general, a particle size of 800 micron or less will suffice, whereas a particle size of 200 micron or less is preferred. A particle size of 100 micron or less is most preferred. The lower limit of the particle size preferably is as close to zero as possible and is determined by the technique used for obt~jning the small block copolymer particles. In general, a lower limit of 1 micron, more suitably 10 micron, will suffice for the purpose of the present invention.
In a preferred embodiment of the present invention, the monovinyl aromatic content is in the range of from 50 to 95% by weight, whereas linear block copolymers comprising two poly(monovinyl aromatic) endblocks A and one poly(conjugated diene) block B are also preferred. The polymer blocks B may be either unhydrogenated or hydrogenated to any desired extent.
The poly(monovinyl aromatic) block A can be derived from styrene, ~-methylstyrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3-dimethylstyrene or mixtures thereof, of which styrene is the preferred monomer. The apparent molecular .
W O 93/25614 ~ ~ 3 71 ~ i~ P ~ /EP93/01408 weight of block A, as determined by gel permeation chromatography using polystyrene standards, can vary within wide ranges. In general, block A may have any apparent molecular weight in the range of from 5,000 to 150,000 and preferably between 8,000 and 70,000.
The poly(con~ugated diene) block B can be derived from 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene or mixtures thereof, of which 1,3-butadiene and isoprene are the most preferred monomers. The number average molecular weight of the rubbery block B is primarily determined by the amount of plasticizer to be absorbed during phase-inversion from elastosol to final product. In general, any number average molecular weight within the range of from 5,000 to 300,000 may be suitable, whereas a number average molecular weight in the range of from 10,000 to 150,000 is preferred.
Basically, the rubber compatible liquid plasticizer has two functions. Firstly, it embodies a liquid medium which enables the block copolymer particles to disperse, thus forming the elastosol according to the invention. This elastosol consists of three separate phases: a first phase formed by the "hard" poly(monovinyl aromatic) do~inc in the block copolymer particles, a second phase formed by the "soft" poly(conjugated diene) domains of said block copolymer particles and a third phase formed by the rubber compatible liquid plasticizer.
The second function of the plasticizer is that upon heating to a temperature above the glass transition temperature of the poly(monovinyl aromatic) d sinC it extends the rubber phase, i.e.
the poly(con~ugated diene) do oinc. After the plasticizer has been absorbed completely by the rubber phase, this rubber phase will have swollen to such an extent that it will now form the continuous phase. At temperatures above the glass transition temperature Of the poly(monovinyl aromatic) domains, said domains will completely soften and upon cooling rearrange into new, interconnecting . 35 poly(monovinyl aromatic) ~- oinc. Hence, a phase inversion has ~ W O 93/25614 2 1 3 7 1 ~ i~ PC~r/EP93/01408 occurred, as the original 2+1 phase-situation has been transformed into a 2 phase-situation: one phase consisting of the newly formed poly(monovinyl aromatic) dom~inc and one phase formed by the plasticizer extended rubber phase. This 2 phase-situation is a homogeneous extended rubber, which remains stable after cooling down to e.g. room temperature.
The weight ratio between the block copolymer and the plasticizer is also very important. If this ratio is too high, i.e.
higher than 10, the viscosity of the obtained elastosol will be too high. However, a too low ratio, i.e. lower than 0.1, will result in an extended rubber being very weak at room temperature, because the plasticizer will not be completely absorbed by the rubber phase. As a result, bleeding out of the plasticizer is likely to occur. In a preferred embodiment said weight ratio lies within the range of from 0.4 to 3.
The plasticizer to be used may be any known rubber compatible liquid plasticizer, such as a naphthenic oil, a paraffinic oil, an aromatic oil or a mixture thereof, as well as a low molecular weight polyisobutylene or polybutylene. A paraffinic oil, however, is preferred.
The elastosol according to the invention can be prepared by any suitable process for preparing dispersions with the proviso that the finally formed block copolymer particles are small enough to be dispersed in an oil. The block copolymer may be produced by any well known block polymerization or copolymerization process including the well known sequential addition of monomer techniques, incremental addition of monomer technique or couFling technique as illustrated in, for example, U.S. patent specifications nos.
3,251,905; 3,390,207; 3,598,887 and 4,219,627. In order to obtain the block copolymer in a powdered form in which the individual particles all have about the same, small size, any of the presently known techniques may be applied. Examples of such techniques are dispersing under high shear and subsequent precipitation, precipitation of a true solution into a non-solvent under - . 35 high-speed ;~inE, cryogenic milling and spray drying. Cryogenic W O 93/2~614 21~ P ~ /EP93/01408 milling and spray drying are preferred, but since the ini 1 obtainable particle size via cryogenic milling is about lS0 micron, whereas spray drying may result in particle sizes of less than 50 micron, the technique of spray drying the block copolymer after its preparation is most preferred. Hence, the elastosol according to the invention can be prepared by a process comprising the steps of:
(a) preparing the block copolymer using conventional techniques;
(b) turning the block copolymer into particles having a particle size of less than 800 micron; and (c) dispersing the thus obtained, finely powdered block copolymer in a rubber compatible liquid plasticizer at room temperature.
The present invention also offers a process for the preparation of a homogeneous, extended rubbery product from said elastosol, which process comprises the steps of:
(a) heating the elastosol under zero-shear conditions to a temperature hi~her than the glass transition temperature of the polymer blocks A; and (b) cooling the resulting homogeneous mass.
This process can be successfully applied for the preparation of films or in the manufacture of any other shaped article, such as gloves, boots and toys. The elastosol first is spreaded in the case of films or brought into its desired shape in the case of shaped articles, after which the above described process for fusion of the elastosol takes place. Consequently, the homogeneous films and shaped articles made from said elastosol are aLso embraced by the present invention.
The invention is further illustrated by the following examples without restricting the scope of the invention to these embodiments.
Example 1 10 parts of a finely powdered styrene-butadiene-styrene block copolymer having a particle size of about 500 micron, were dispersed in 4 parts of the paraffinic oil Primol 352 (Primol is a trade mark) at room temperature. This dispersion was spreaded as a thin layer on siliconized paper. Upon heating the elastosol in an ~ W O 93/2S614 ~13 71 ~ '~ PC~r/EP93/01408 g oven for 10 minutes at 200 C followed by cooling to room temperature, a homogeneous film was obtained.
Example 2 K-Resin 04 (K-Resin is a trade mark), an asymmetric, branched block copolymer of formula (S-B)nX, with S representing a polystyrene block, B a polybutadiene block and X a polyepoxy resin and with n varying from 4 to 10, said block copolymer having a styrene content of about 70~ by weight based on the total block copolymer, was spray dried. The resulting ?~i~n particle size of the block copolymer particles was 16 micron.
The polymer particles were dispersed in a paraffinic oil (Primol 352) by stirring, the weight ratio polymer to oil being 1:1. The dispersion was spreaded as a thin layer on siliconized paper and subsequently heated in an oven for 10 minutes at 180 C.
After cooling to room temperature a homogeneous film was obtained.
,
(a) preparing the block copolymer using conventional techniques;
(b) turning the block copolymer into particles having a particle size of less than 800 micron; and (c) dispersing the thus obtained, finely powdered block copolymer in a rubber compatible liquid plasticizer at room temperature.
The present invention also offers a process for the preparation of a homogeneous, extended rubbery product from said elastosol, which process comprises the steps of:
(a) heating the elastosol under zero-shear conditions to a temperature hi~her than the glass transition temperature of the polymer blocks A; and (b) cooling the resulting homogeneous mass.
This process can be successfully applied for the preparation of films or in the manufacture of any other shaped article, such as gloves, boots and toys. The elastosol first is spreaded in the case of films or brought into its desired shape in the case of shaped articles, after which the above described process for fusion of the elastosol takes place. Consequently, the homogeneous films and shaped articles made from said elastosol are aLso embraced by the present invention.
The invention is further illustrated by the following examples without restricting the scope of the invention to these embodiments.
Example 1 10 parts of a finely powdered styrene-butadiene-styrene block copolymer having a particle size of about 500 micron, were dispersed in 4 parts of the paraffinic oil Primol 352 (Primol is a trade mark) at room temperature. This dispersion was spreaded as a thin layer on siliconized paper. Upon heating the elastosol in an ~ W O 93/2S614 ~13 71 ~ '~ PC~r/EP93/01408 g oven for 10 minutes at 200 C followed by cooling to room temperature, a homogeneous film was obtained.
Example 2 K-Resin 04 (K-Resin is a trade mark), an asymmetric, branched block copolymer of formula (S-B)nX, with S representing a polystyrene block, B a polybutadiene block and X a polyepoxy resin and with n varying from 4 to 10, said block copolymer having a styrene content of about 70~ by weight based on the total block copolymer, was spray dried. The resulting ?~i~n particle size of the block copolymer particles was 16 micron.
The polymer particles were dispersed in a paraffinic oil (Primol 352) by stirring, the weight ratio polymer to oil being 1:1. The dispersion was spreaded as a thin layer on siliconized paper and subsequently heated in an oven for 10 minutes at 180 C.
After cooling to room temperature a homogeneous film was obtained.
,
Claims (12)
1. An elastosol comprising:
(a) a finely powdered, linear or branched block copolymer having a particle size of 800 micron or less, comprising at least one polymer block A comprising at least 80% by weight of a monovinyl aromatic compound and at least one, optionally hydrogenated, polymer block B comprising at least 80% by weight of a conjugated diene, wherein the content of monovinyl aromatic compound is at least 40% by weight based on the weight of the block copolymer, and (b) a rubber compatible liquid plasticizer, the weight ratio (a)/(b) being in the range of from 0.1 to 10.
(a) a finely powdered, linear or branched block copolymer having a particle size of 800 micron or less, comprising at least one polymer block A comprising at least 80% by weight of a monovinyl aromatic compound and at least one, optionally hydrogenated, polymer block B comprising at least 80% by weight of a conjugated diene, wherein the content of monovinyl aromatic compound is at least 40% by weight based on the weight of the block copolymer, and (b) a rubber compatible liquid plasticizer, the weight ratio (a)/(b) being in the range of from 0.1 to 10.
2. An elastosol according to claim 1, characterized in that the block copolymer has a particle size of 200 micron or less.
3. An elastosol according to claim 2, characterized in that the block copolymer has a particle size of 100 micron or less.
4. An elastosol according to any one of the claims 1 to 3, characterized in that the content of monovinyl aromatic compound in component (a) is in the range of from 50 to 95% by weight.
5. An elastosol according to any one of the preceding claims, characterized in that component (a) is a linear block copolymer comprising two endblocks A and one midblock B.
6. An elastosol according to any one of the preceding claims, characterized in that the monovinyl aromatic compound is styrene and the conjugated diene is 1,3-butadiene.
7. An elastosol according of one or more of the claims 1 to 6, characterized in that component (b) is a paraffinic oil.
8. An elastosol according to one or more of the claims 1 to 7, characterized in that the weight ratio (a)/(b) is in the range of from 0.4 to 3.
9. A process for the preparation of an elastosol according to one or more of the claims 1 to 8 comprising the steps of:
(a) preparing the block copolymer using conventional techniques;
(b) turning the block copolymer into particles having a particle size of less than 800 micron; and (c) dispersing the thus obtained, finely powdered block copolymer in an oil at room temperature.
(a) preparing the block copolymer using conventional techniques;
(b) turning the block copolymer into particles having a particle size of less than 800 micron; and (c) dispersing the thus obtained, finely powdered block copolymer in an oil at room temperature.
10. A process according to claim 9, wherein step (b) is carried out by cyrogenic milling or spray drying the block copolymer obtained from step (a).
11. A process according to claim 10, wherein step (b) is carried out by spray drying the block copolymer.
12. A process for the preparation of a homogeneous rubbery product from the elastosol according to one or more of the claims 1 to 8, comprising the steps of:
(a) heating the elastosol under zero-shear conditions to a temperature higher than the glass transition temperature of the polymer blocks A;
and (b) cooling the resulting homogeneous mass.
(a) heating the elastosol under zero-shear conditions to a temperature higher than the glass transition temperature of the polymer blocks A;
and (b) cooling the resulting homogeneous mass.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP92201643 | 1992-06-05 | ||
| EP92201643.1 | 1992-06-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2137154A1 true CA2137154A1 (en) | 1993-12-23 |
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ID=8210667
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002137154A Abandoned CA2137154A1 (en) | 1992-06-05 | 1993-06-03 | Elastosols, preparation, use and products thereof |
Country Status (18)
| Country | Link |
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| US (1) | US5900455A (en) |
| EP (1) | EP0643740B1 (en) |
| JP (1) | JP3207425B2 (en) |
| KR (1) | KR100284820B1 (en) |
| CN (1) | CN1057551C (en) |
| AT (1) | ATE157688T1 (en) |
| AU (1) | AU670294B2 (en) |
| BR (1) | BR9306471A (en) |
| CA (1) | CA2137154A1 (en) |
| DE (1) | DE69313634T2 (en) |
| DK (1) | DK0643740T3 (en) |
| ES (1) | ES2107034T3 (en) |
| FI (1) | FI945672A0 (en) |
| GR (1) | GR3025270T3 (en) |
| NO (1) | NO306729B1 (en) |
| RU (1) | RU2148596C1 (en) |
| TW (1) | TW227009B (en) |
| WO (1) | WO1993025614A1 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6072004A (en) * | 1997-12-19 | 2000-06-06 | Shell Oil Company | Thermofusible elastomer compositions |
| KR100354425B1 (en) * | 2000-06-22 | 2002-09-30 | 한국신발피혁연구소 | Method for shock absorptive foaming for footwear |
| DE10194268D2 (en) * | 2000-10-09 | 2003-11-06 | Zapf Creation Ag | Process for producing at least one body and flowable mixture for use in such a process |
| US7592390B2 (en) * | 2006-03-24 | 2009-09-22 | Kraton Polymers U.S. Llc | Hydrogenated block copolymer compositions |
| US7994256B2 (en) * | 2008-01-18 | 2011-08-09 | Kraton Polymers U.S. Llc | Gel compositions |
| US9304231B2 (en) | 2014-02-04 | 2016-04-05 | Kraton Polymers U.S. Llc | Heat fusible oil gels |
| CN105987820B (en) * | 2015-02-12 | 2019-06-04 | 苏州宝时得电动工具有限公司 | Air purifier purification device life-span prediction method and system |
| US11891503B2 (en) * | 2017-03-16 | 2024-02-06 | Ineos Styrolution Group Gmbh | Non-sticky, soft and transparent styrenic thermoplastic elastomers |
Family Cites Families (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3695477A (en) * | 1970-05-18 | 1972-10-03 | Grace W R & Co | Plastisols and gaskets |
| US4143185A (en) * | 1972-02-25 | 1979-03-06 | Exxon Research & Engineering Co. | Fabrication of coatings from thermoplastic ionomers |
| DE2354223A1 (en) * | 1973-10-30 | 1975-05-28 | Hoechst Ag | LIQUID DETERGENT CONCENTRATES |
| US3827999A (en) * | 1973-11-09 | 1974-08-06 | Shell Oil Co | Stable elastomeric polymer-oil compositions |
| DE2722752B2 (en) * | 1977-05-20 | 1979-04-12 | Roehm Gmbh, 6100 Darmstadt | Plastisols based on methyl methacrylate copolymers |
| SU823404A1 (en) * | 1977-10-17 | 1981-04-23 | Kuznetsova Valentina A | Composition for making writing leads |
| CA1132283A (en) * | 1978-04-03 | 1982-09-21 | Fred J. Burwell | High oil-elastomer compositions |
| JPS5998709A (en) * | 1982-11-29 | 1984-06-07 | Olympus Optical Co Ltd | Method for judging particle agglomeration pattern |
| GB2168991A (en) * | 1984-12-28 | 1986-07-02 | Shell Int Research | Thermally reversible encapsulating gel compound for filling cables |
| US4877566A (en) * | 1985-04-04 | 1989-10-31 | Pop-Limited | Non-toxic rubber-based composition and method for making the rubber based composition |
| JPH0697203B2 (en) * | 1986-08-29 | 1994-11-30 | 富士レビオ株式会社 | Particle aggregation determination device |
| US5192692A (en) * | 1989-07-25 | 1993-03-09 | Olympus Optical Co., Ltd. | Method of judging particle agglutination pattern |
| US5143968A (en) * | 1989-08-11 | 1992-09-01 | The Dow Chemical Company | Polystyrene-polyisoprene-polystyrene block copolymers, hot melt adhesive compositions, and articles produced therefrom |
| GB8922445D0 (en) * | 1989-10-05 | 1989-11-22 | Raychem Ltd | Gels |
| JPH03280784A (en) * | 1990-03-29 | 1991-12-11 | Nec Corp | Facsimile equipment |
| US5668209A (en) * | 1990-10-31 | 1997-09-16 | Teroson Gmbh | Plastisol composition |
-
1993
- 1993-05-24 TW TW082104080A patent/TW227009B/zh active
- 1993-06-03 AT AT93912880T patent/ATE157688T1/en not_active IP Right Cessation
- 1993-06-03 ES ES93912880T patent/ES2107034T3/en not_active Expired - Lifetime
- 1993-06-03 DE DE69313634T patent/DE69313634T2/en not_active Expired - Fee Related
- 1993-06-03 CA CA002137154A patent/CA2137154A1/en not_active Abandoned
- 1993-06-03 BR BR9306471A patent/BR9306471A/en not_active IP Right Cessation
- 1993-06-03 CN CN93106686A patent/CN1057551C/en not_active Expired - Fee Related
- 1993-06-03 WO PCT/EP1993/001408 patent/WO1993025614A1/en active IP Right Grant
- 1993-06-03 JP JP50109094A patent/JP3207425B2/en not_active Expired - Fee Related
- 1993-06-03 KR KR1019940704447A patent/KR100284820B1/en not_active IP Right Cessation
- 1993-06-03 RU RU94046264A patent/RU2148596C1/en active
- 1993-06-03 EP EP93912880A patent/EP0643740B1/en not_active Expired - Lifetime
- 1993-06-03 DK DK93912880.7T patent/DK0643740T3/en active
- 1993-06-03 AU AU43228/93A patent/AU670294B2/en not_active Ceased
- 1993-06-04 US US08/072,210 patent/US5900455A/en not_active Expired - Fee Related
-
1994
- 1994-12-01 FI FI945672A patent/FI945672A0/en unknown
- 1994-12-01 NO NO944623A patent/NO306729B1/en not_active IP Right Cessation
-
1997
- 1997-11-05 GR GR970402908T patent/GR3025270T3/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| NO306729B1 (en) | 1999-12-13 |
| CN1079485A (en) | 1993-12-15 |
| US5900455A (en) | 1999-05-04 |
| TW227009B (en) | 1994-07-21 |
| DK0643740T3 (en) | 1997-09-15 |
| EP0643740B1 (en) | 1997-09-03 |
| FI945672A (en) | 1994-12-01 |
| ATE157688T1 (en) | 1997-09-15 |
| GR3025270T3 (en) | 1998-02-27 |
| KR950701952A (en) | 1995-05-17 |
| WO1993025614A1 (en) | 1993-12-23 |
| DE69313634D1 (en) | 1997-10-09 |
| DE69313634T2 (en) | 1998-01-08 |
| ES2107034T3 (en) | 1997-11-16 |
| AU670294B2 (en) | 1996-07-11 |
| NO944623L (en) | 1994-12-01 |
| BR9306471A (en) | 1998-06-30 |
| EP0643740A1 (en) | 1995-03-22 |
| RU2148596C1 (en) | 2000-05-10 |
| NO944623D0 (en) | 1994-12-01 |
| AU4322893A (en) | 1994-01-04 |
| RU94046264A (en) | 1996-10-10 |
| KR100284820B1 (en) | 2001-03-15 |
| JPH07506872A (en) | 1995-07-27 |
| JP3207425B2 (en) | 2001-09-10 |
| CN1057551C (en) | 2000-10-18 |
| FI945672A0 (en) | 1994-12-01 |
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