CA1049686A - Process for producing transparent block copolymer resin from a vinyl aromatic monomer and a conjugated diene - Google Patents
Process for producing transparent block copolymer resin from a vinyl aromatic monomer and a conjugated dieneInfo
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- CA1049686A CA1049686A CA217,483A CA217483A CA1049686A CA 1049686 A CA1049686 A CA 1049686A CA 217483 A CA217483 A CA 217483A CA 1049686 A CA1049686 A CA 1049686A
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- process according
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- vinyl aromatic
- monomer
- aromatic compound
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- 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
- C08F297/00—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer
- C08F297/02—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type
- C08F297/04—Macromolecular compounds obtained by successively polymerising different monomer systems using a catalyst of the ionic or coordination type without deactivating the intermediate polymer using a catalyst of the anionic type polymerising vinyl aromatic monomers and conjugated dienes
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- Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Graft Or Block Polymers (AREA)
Abstract
PROCESS FOR PRODUCING TRANSPARENT
BLOCK COPOLYMER RESIN
ABSTRACT OF THE DISCLOSURE
In block-copolymerizing a vinyl aromatic compound and a conjugated diene in a hydrocarbon solvent using an organolithium compound as initiator, a transparent block copolymer resin characterized by having elastomeric random copolymer blocks may be produced by continuously adding a mixture of the vinyl aromatic compound and the conjugated diene.
The block copolymer resin thus obtained is transparent, excellent in mechanical characteristics and may be used in the fields of sheetings, films, and various molded articles.
BLOCK COPOLYMER RESIN
ABSTRACT OF THE DISCLOSURE
In block-copolymerizing a vinyl aromatic compound and a conjugated diene in a hydrocarbon solvent using an organolithium compound as initiator, a transparent block copolymer resin characterized by having elastomeric random copolymer blocks may be produced by continuously adding a mixture of the vinyl aromatic compound and the conjugated diene.
The block copolymer resin thus obtained is transparent, excellent in mechanical characteristics and may be used in the fields of sheetings, films, and various molded articles.
Description
1 This invenl;ion relate; -to a process for producing a novel block copolymer resin which is transparent and excellent in mechanical properties, particularly in elongation and impact strength.
5 More particularly~ it relates to a novel process for producing a block copolymer resin which is transparent and excellent in mechanical properties by block-copolymerizing in a specified manner a vinyl aromatic compound monomer and a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as initiator.
It has been known that various block copolymers of different structures can be obtained by copolymerizing vinyl aromatic compounds and conjugated : 15 dienes with an alkali metal or an organo-alkali-metal compound used as initiator. For eixample, in Japanese Patent Publication Nos. 19,286/61 and 2,423/73, are described processes for producing a transparent resin from styrene, butadiene, and the like, by two-stage 20 block copolymerization; in Japanese Patent Publication Nos. 3,252/72 and 28,915/72, are disclosed processes for producing a transparent resin by adding each of the monomers alternately in four or five stages; in Japanese Patent Publication No. 20,038/73, German Patent Applica-25 tion Laid-open (Offenlegungsschrift) 2,120,232, and Japanese Patent Application Laid-open (kokai) No.
7,597/71, are proposed processes for producing a transparent resin by single stage polymerization using i the same monomers as mentioned above.
These processes generally ernploy as the 6~3~
1 po:Lymeri%ation inl-tiator an organolithium compound known as one-end initia-tion type or -that known as both-ends initiation type. In either case, the process is characterlzed by forming in the polymer molecule a plastic block composed chiefly of a vinyl aromatic compound polymer and an elastomeric block composed chiefly of` a conjugated diene polymer by means of a living anionic polymerization tec~mique.
It has been known, however, that when the elastomeric block is composed of a homopolymer of a conjugated diene alone, the bloc~ copolymer obtained is unsatisfactory for practical use in elongation, impact strength, and flexural strength among mechanical properties (the afore-cited Japanese Patent Publication No. 19,286/61, Example 11; Japanese Patent Publication No. 2,~23/73), giving rise to disadvantages of the copolymer in practical application as a resin. On the other hand~
in the processes where a monomer mixture is added all at a time [the afore-cited Japanese Patent Application 20 Laid-open (Kokai) No. 7,597/71; German Patent Application Laid open (Offenlegungsschrift) No. 2,120,232; Japanese Patent Publication No. 20,038/73], there is always formed a copolymer block between the plastic block composed chiefly of a vinyl aromatic compound polymer 25 and the elastomeric block composed chiefly of a conjugated diene polymer~ owing to the difference in monomer reactivities. In this case, however, a technical difficulty is encolmtered in removing a large quantity of heat evolved from the polymerization 30 of monomers which have been added all at a time.
1 Such a difficu:Lty would be deterrent to -the commerciali-zation of the process.
The presen-t inventors had conducted extensive investigations to develop a process for producing a transparent resin of excellent mechanical properties from a vinyl aromatic compound monomer and a conjugated diene monomer as starting materialsO As a result, it was found that the above object can be achieved by an anionic living polymerization process using an organoli-thium compound as initiator, which process comprisesselecting a specified combination of the methods of addition of monomers so as to form a copolymer molecule having at least one plastic block composed of a vinyl aromatic compound homopolymer and at least one elasto-meric block composed of a random copolymer of a vinylaromatic compound and a conjugated diene. Based on the finding, the present invention has been accomplished.
An object of the present invention is to provide novel block copolymer resins produced from a vinyl aromatic compound monomer and a conjugated diene monomer as starting materials and a process for producing same.
Other object of the present invention is to provide novel block copolymer resins which are trans-parent~ excellent in mechanical properties and in addition good processable.
Further objects and advantages of the present invention are will be apparent from the description below.
The present invention provides a process for 9~6 1 producing a transparent block copolymer resin, whichcomprises the following f`our essen-tia.l features in block-copolymerizing in a hydrocarbon solven-t 90 to 65 parts by weigh-t of a vinyl a.romatic compound monomer and lO to 35 parts by weigh-t of a conjuga-ted diene monomer by using an organolithium compound as initia.tor:
(1) formation of a block copolymer having in a molecule at least one pla.stic block composed of a vinyl a.romatic compound homopolymer and at least one elastomeric block composed of a random copolymer of a vinyl aroma.tic compound and a conjuga.ted diene; (2) formation of the homopolymer block with 50 to 90 % by weight of the vinyl aromatic compound monomer and formation of the random copolymer block by adding continuously a monomer mixture of a fixed composition comprising the vinyl aromatic compound and the conjugated diene in a weight ratio from 0.1 to 3.0; (3) forma.tion of the block copolymer so as to have a mean molecular weight of 0.35 to 1.8 d~g in terms of intrinsic viscosity as :
measured in toluene at 30C; and (~) polymerization in the presence or absence of 0.01 to 5 mole-% ba.sed on the total monomer of a Lewis base compound. The , process of this invention presents no particula.r difficulty in commercialization. The block copolymer resin thus produced is cha.racterized by transparency, excellent mechanical properties, pa.rticularly high impact strength, little clouding under bending stress, and, in addition, good processability, permitting the '.! resin to be used for general purpose.
The process of this invention is disclosed ~' ' ,.
~9~
1 below in further detail.
The vinyl a.roma-tic compounds for use in this invention are s-tyrene, a-me-thylstyrene, vinylnaphtha.lene, and nucleus-substitu-ted styrenes such a.s vinyltouene, 5 or mixtures of these. The conjugated dienes for use are 1,3-butadiene and substituted butadienes such as isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, and l-phenyl-1~3-butadiene, or mixtures of these.
Particula.rly preferred are styrene among the vinyl aromatic compounds and 1,3-buta.diene among the conjugated dienes, in view of availability and effectiveness.
The weight ratio of monomers for use in this invention is 90 to 65 parts by weight of a vinyl aromatic compound to 10 to 35 parts by weight of a conjugated diene. When more than 90 pa.rts by weight of a vinyl aromatic compound is used, the elonga.tion and impact strength among mechanica.l proper-ties of the resin become decreased, while when less than 65 parts by weight of the compound is used? the tensile strength and the processability both become undesirably deterio-rated. In the present process, at lea.st one homopolymer block is formed in a molecule from the vinyl aroma.tic compound monomer and 50 to 90 % by weight of the monomer is used in forming such blocks.
The hydrocarbon solvents to be used in the present process are aromatic hydrocarbons such a.s benzene, toluene, xylene, and ethylbenzene; a.liphatic hydrocarbons such a.s hexane, hepta~e, and the like;
and cycloal.iphatic hydrocarbons such as cyclopentane, cyclohexane~ and methylcyclohexane. These are inert 968~
1 ancl used each alone or in mixtures of two or more.The a.mount to be used o these hyclrocaIbon solvents is generally 1 to 20 pa.rts by weigh-t f`or 1 part by weight of the -to-tal monomer. Before use, these solvents a.nd the monomers should be thoroughly freed from such substances a.s water, oxygen, ca.rbon dioxide, some sulfur compounds, and acetylenes, which will destroy the initiators used in the present process and the active terminals of the growing polymer. As one mode of carring out this invention, it is a.lso possible to obtain the blocX copolymer not only in solution but also in suspension in a solvent, by properly selecting the order of addition of solvents and monomers.
The organolithium compounds to be used a.s 15 initiator in the present process a.re those generally ~:
known as one-end initiation type or both-ends initiation type. Examples of individual compounds include ethyllithium, propyllithium, butyl.lithium, amyllitium, trimethylenedilithium, tetramethylenedilithium, hexyllithium, cyclohexyllithium, phenyllithium, tolyllithium, naphthyllithium, and, in addition, a.
lithium complex with a condensed- or non-condensed-ring aromatic compound, such as for exa.mple, naphthalene, stilbene~ or biphenyl and a living oligobutadienyl-dilithium or oli.goisoprenyldithium. These can be used each alone or in mixtures of two or more. The amount to be used of these organolithium compounds is generally 0.002 to 5 mole-~, preferably 0.005 -to 1.5 mole-% based : on tota] monomer.
In the present process, at lea.st one random 1 copo~ymer block is formed in the molecule frorn a vinyl aroma.tic compound a.nd a conjuga-ted diene. In this step, in order to allow the random copolymeriza-tion to proceed smoo-thly, a. specified a.mount of a Lewis base compound such as an ether compound or a. tertla.ry amine compound can be used. Exa.mples of such ether compounds are cyclic ethers such a.s tetrahydrofuran and tetrahydropyrane; aliphatic monoethers such as diethyl ether and dibutyl ether; a.nd a.liphatic poly-ethers such as diethylene glycol dimethyl ether anddiethylene glycol diethyl ether. Examples of the tertiary amine compounds are triethyla.mine~ tripropy-lamine, tributylamine, and, in addition, such compounds as N,N'-dimethylaniline, pyridine, and quinoline.
When such a Lewis base compound is used, the a.mount to be used is 0.01 to 5 mole-%, preferably 0.05 to 2 mole-%, based on total monomer. It is undesirable to use the Lewis base compound.in excess of the sa.id upper limit, because then the content of vinyl-bond in the random copolymer block formed from a. vinyl a.roma.tic compound and a conjugated diene becomes so high that the mechanical properties of resin become markedly~
deteriora.ted, particula.rly a.t low temperatures. The Lewis base compound can be a.dded a.t any time, wi-th no particular restriction, before the step of forming the copolymer block.
In the process of this invention, a vinyl aromatic compound monomer and a conjuga.ted diene monomer are block-copolyrnerized in the presence of an organolithil~m compound. The block copolyrner molecule ~4~
1 thus formed should contain at least one homopolymer block cr the vinyl a.roma-tic compound and at least one bloc~ of a random copolymer block of the vinyl aromatic compound and the conjuga.ted diene. In the process of` this invention, moreover, 50 to 90 % by weight of the vinyl aromatic compound monomer a.re used to form the vinyl aroma.tic compound homopolymer block.
A block copolymer of such a structure that the amount of a vinyl aromatic compound used in 10 formlng the homopolymer block is less than 50 % by ~:
weight of the total vinyl aroma.tic compound, pa.rticularly said amount is zero, is undesirable because of defective mechanical properties, particularly defective tensile strength and hardness. On the other hand, a block copolymer of such a structure that more than 90 %, particularly 100 %, by weight of the vinyl aromatic compound are used to form the homopolymer block can ~.
no more be called a useful resin, because of inferior mechanical properties, particularly inferior elongation~
inferior impact strength and a high clouding under bending stress. In a block copolymer having two or more homopolymer blocks in a molecule, the sum of vinyl aromatic monomer used in each homopolymer block should be 50 to 90 % by weight of the total vinyl aromatic monomer.
Further, in the present process, in order to form the aforesa.id random copolymer block, there is adopted a method in which a monomer mixture of a. fixed composition comprising the vinyl aromatic compound and the conjugated diene in a weight ratio from 0.1 to 3.0 1 is con-tinuously adcled. If the ratio between the vinyl aromatic compound and the conjugated d:iene is below the lower limit of the above-noted range, the impact strength among mechanical properties of the block copolymer resin formed becomes decreased and the clouding under bending s-tress becomes increased, while if the ra.tio is above the upper limit, -the tensile strength and hardness of the block copolymer resin formed become inferior, both cases being undesirable.
In the case of a block copolymer ha.ving two or more random copolymer blocks of the vinyl aromatic compound and the conjugated diene in a molecule, it is necessary to maintain the ratio between the vinyl aroma.tic compound and the conjugated diene within the above-said range from 0.1 to 3.0 in each of the copolymer blocks and also in copolymer blocks as a whole; the said fixed ratio in each of the copolymer blocks may be either the sam.e or different within the said range so long as the above-mentioned conditions are satisfied.
In forming the random copolymer block by continuously feeding a vinyl aromatic compound and a conjugated diene~ both monomers can be fed either in a mixture or separately to the polymerization system, while maintaining a fixed monomer ratio within the aforesaid range. In either case, it is necessary to feed the vinyl aromatic compound and the conjugated.
diene, in a fixed ratio, continuously to the polymeri-zation system under such conditions of tempera.ture and feeding rate tha.t both monomers will not accumulate in the sy.stem. It is also feasible to feed the vinyl ~96 51~
l aromatic compound and the conju~a-ted dicne~ while mai.ntaining the fixed monomer ra.tio, semi-consecu-tively to the polymerization system in a manner substantially approximating the continuous feeding. The above-said con-tinuous feeding is one of the charac-teristic features of the present process, which allows effective removal of a large quantity of heat generated from the polymerization reaction when carried out commercially and, moreover, preventing side reactions such as gelation accompanying the heat generation.
Although the block copolymer formed by the present process has no restriction placed on its .
structure so long as the conditions mentioned in the foregoing are satisfied, examples of particularly preferred structures are given below, wherein Sl, S2 and S3 represent homopolymer bloc~s of a vinyl a.romatic compound and (S/B)l and (S/B)2 represent copolymer bloc~s of a vinyl aromatic compound and a conjuga-ted di.ene. : .
1) Sl - (S/B)
5 More particularly~ it relates to a novel process for producing a block copolymer resin which is transparent and excellent in mechanical properties by block-copolymerizing in a specified manner a vinyl aromatic compound monomer and a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as initiator.
It has been known that various block copolymers of different structures can be obtained by copolymerizing vinyl aromatic compounds and conjugated : 15 dienes with an alkali metal or an organo-alkali-metal compound used as initiator. For eixample, in Japanese Patent Publication Nos. 19,286/61 and 2,423/73, are described processes for producing a transparent resin from styrene, butadiene, and the like, by two-stage 20 block copolymerization; in Japanese Patent Publication Nos. 3,252/72 and 28,915/72, are disclosed processes for producing a transparent resin by adding each of the monomers alternately in four or five stages; in Japanese Patent Publication No. 20,038/73, German Patent Applica-25 tion Laid-open (Offenlegungsschrift) 2,120,232, and Japanese Patent Application Laid-open (kokai) No.
7,597/71, are proposed processes for producing a transparent resin by single stage polymerization using i the same monomers as mentioned above.
These processes generally ernploy as the 6~3~
1 po:Lymeri%ation inl-tiator an organolithium compound known as one-end initia-tion type or -that known as both-ends initiation type. In either case, the process is characterlzed by forming in the polymer molecule a plastic block composed chiefly of a vinyl aromatic compound polymer and an elastomeric block composed chiefly of` a conjugated diene polymer by means of a living anionic polymerization tec~mique.
It has been known, however, that when the elastomeric block is composed of a homopolymer of a conjugated diene alone, the bloc~ copolymer obtained is unsatisfactory for practical use in elongation, impact strength, and flexural strength among mechanical properties (the afore-cited Japanese Patent Publication No. 19,286/61, Example 11; Japanese Patent Publication No. 2,~23/73), giving rise to disadvantages of the copolymer in practical application as a resin. On the other hand~
in the processes where a monomer mixture is added all at a time [the afore-cited Japanese Patent Application 20 Laid-open (Kokai) No. 7,597/71; German Patent Application Laid open (Offenlegungsschrift) No. 2,120,232; Japanese Patent Publication No. 20,038/73], there is always formed a copolymer block between the plastic block composed chiefly of a vinyl aromatic compound polymer 25 and the elastomeric block composed chiefly of a conjugated diene polymer~ owing to the difference in monomer reactivities. In this case, however, a technical difficulty is encolmtered in removing a large quantity of heat evolved from the polymerization 30 of monomers which have been added all at a time.
1 Such a difficu:Lty would be deterrent to -the commerciali-zation of the process.
The presen-t inventors had conducted extensive investigations to develop a process for producing a transparent resin of excellent mechanical properties from a vinyl aromatic compound monomer and a conjugated diene monomer as starting materialsO As a result, it was found that the above object can be achieved by an anionic living polymerization process using an organoli-thium compound as initiator, which process comprisesselecting a specified combination of the methods of addition of monomers so as to form a copolymer molecule having at least one plastic block composed of a vinyl aromatic compound homopolymer and at least one elasto-meric block composed of a random copolymer of a vinylaromatic compound and a conjugated diene. Based on the finding, the present invention has been accomplished.
An object of the present invention is to provide novel block copolymer resins produced from a vinyl aromatic compound monomer and a conjugated diene monomer as starting materials and a process for producing same.
Other object of the present invention is to provide novel block copolymer resins which are trans-parent~ excellent in mechanical properties and in addition good processable.
Further objects and advantages of the present invention are will be apparent from the description below.
The present invention provides a process for 9~6 1 producing a transparent block copolymer resin, whichcomprises the following f`our essen-tia.l features in block-copolymerizing in a hydrocarbon solven-t 90 to 65 parts by weigh-t of a vinyl a.romatic compound monomer and lO to 35 parts by weigh-t of a conjuga-ted diene monomer by using an organolithium compound as initia.tor:
(1) formation of a block copolymer having in a molecule at least one pla.stic block composed of a vinyl a.romatic compound homopolymer and at least one elastomeric block composed of a random copolymer of a vinyl aroma.tic compound and a conjuga.ted diene; (2) formation of the homopolymer block with 50 to 90 % by weight of the vinyl aromatic compound monomer and formation of the random copolymer block by adding continuously a monomer mixture of a fixed composition comprising the vinyl aromatic compound and the conjugated diene in a weight ratio from 0.1 to 3.0; (3) forma.tion of the block copolymer so as to have a mean molecular weight of 0.35 to 1.8 d~g in terms of intrinsic viscosity as :
measured in toluene at 30C; and (~) polymerization in the presence or absence of 0.01 to 5 mole-% ba.sed on the total monomer of a Lewis base compound. The , process of this invention presents no particula.r difficulty in commercialization. The block copolymer resin thus produced is cha.racterized by transparency, excellent mechanical properties, pa.rticularly high impact strength, little clouding under bending stress, and, in addition, good processability, permitting the '.! resin to be used for general purpose.
The process of this invention is disclosed ~' ' ,.
~9~
1 below in further detail.
The vinyl a.roma-tic compounds for use in this invention are s-tyrene, a-me-thylstyrene, vinylnaphtha.lene, and nucleus-substitu-ted styrenes such a.s vinyltouene, 5 or mixtures of these. The conjugated dienes for use are 1,3-butadiene and substituted butadienes such as isoprene, piperylene, 2,3-dimethyl-1,3-butadiene, and l-phenyl-1~3-butadiene, or mixtures of these.
Particula.rly preferred are styrene among the vinyl aromatic compounds and 1,3-buta.diene among the conjugated dienes, in view of availability and effectiveness.
The weight ratio of monomers for use in this invention is 90 to 65 parts by weight of a vinyl aromatic compound to 10 to 35 parts by weight of a conjugated diene. When more than 90 pa.rts by weight of a vinyl aromatic compound is used, the elonga.tion and impact strength among mechanica.l proper-ties of the resin become decreased, while when less than 65 parts by weight of the compound is used? the tensile strength and the processability both become undesirably deterio-rated. In the present process, at lea.st one homopolymer block is formed in a molecule from the vinyl aroma.tic compound monomer and 50 to 90 % by weight of the monomer is used in forming such blocks.
The hydrocarbon solvents to be used in the present process are aromatic hydrocarbons such a.s benzene, toluene, xylene, and ethylbenzene; a.liphatic hydrocarbons such a.s hexane, hepta~e, and the like;
and cycloal.iphatic hydrocarbons such as cyclopentane, cyclohexane~ and methylcyclohexane. These are inert 968~
1 ancl used each alone or in mixtures of two or more.The a.mount to be used o these hyclrocaIbon solvents is generally 1 to 20 pa.rts by weigh-t f`or 1 part by weight of the -to-tal monomer. Before use, these solvents a.nd the monomers should be thoroughly freed from such substances a.s water, oxygen, ca.rbon dioxide, some sulfur compounds, and acetylenes, which will destroy the initiators used in the present process and the active terminals of the growing polymer. As one mode of carring out this invention, it is a.lso possible to obtain the blocX copolymer not only in solution but also in suspension in a solvent, by properly selecting the order of addition of solvents and monomers.
The organolithium compounds to be used a.s 15 initiator in the present process a.re those generally ~:
known as one-end initiation type or both-ends initiation type. Examples of individual compounds include ethyllithium, propyllithium, butyl.lithium, amyllitium, trimethylenedilithium, tetramethylenedilithium, hexyllithium, cyclohexyllithium, phenyllithium, tolyllithium, naphthyllithium, and, in addition, a.
lithium complex with a condensed- or non-condensed-ring aromatic compound, such as for exa.mple, naphthalene, stilbene~ or biphenyl and a living oligobutadienyl-dilithium or oli.goisoprenyldithium. These can be used each alone or in mixtures of two or more. The amount to be used of these organolithium compounds is generally 0.002 to 5 mole-~, preferably 0.005 -to 1.5 mole-% based : on tota] monomer.
In the present process, at lea.st one random 1 copo~ymer block is formed in the molecule frorn a vinyl aroma.tic compound a.nd a conjuga-ted diene. In this step, in order to allow the random copolymeriza-tion to proceed smoo-thly, a. specified a.mount of a Lewis base compound such as an ether compound or a. tertla.ry amine compound can be used. Exa.mples of such ether compounds are cyclic ethers such a.s tetrahydrofuran and tetrahydropyrane; aliphatic monoethers such as diethyl ether and dibutyl ether; a.nd a.liphatic poly-ethers such as diethylene glycol dimethyl ether anddiethylene glycol diethyl ether. Examples of the tertiary amine compounds are triethyla.mine~ tripropy-lamine, tributylamine, and, in addition, such compounds as N,N'-dimethylaniline, pyridine, and quinoline.
When such a Lewis base compound is used, the a.mount to be used is 0.01 to 5 mole-%, preferably 0.05 to 2 mole-%, based on total monomer. It is undesirable to use the Lewis base compound.in excess of the sa.id upper limit, because then the content of vinyl-bond in the random copolymer block formed from a. vinyl a.roma.tic compound and a conjugated diene becomes so high that the mechanical properties of resin become markedly~
deteriora.ted, particula.rly a.t low temperatures. The Lewis base compound can be a.dded a.t any time, wi-th no particular restriction, before the step of forming the copolymer block.
In the process of this invention, a vinyl aromatic compound monomer and a conjuga.ted diene monomer are block-copolyrnerized in the presence of an organolithil~m compound. The block copolyrner molecule ~4~
1 thus formed should contain at least one homopolymer block cr the vinyl a.roma-tic compound and at least one bloc~ of a random copolymer block of the vinyl aromatic compound and the conjuga.ted diene. In the process of` this invention, moreover, 50 to 90 % by weight of the vinyl aromatic compound monomer a.re used to form the vinyl aroma.tic compound homopolymer block.
A block copolymer of such a structure that the amount of a vinyl aromatic compound used in 10 formlng the homopolymer block is less than 50 % by ~:
weight of the total vinyl aroma.tic compound, pa.rticularly said amount is zero, is undesirable because of defective mechanical properties, particularly defective tensile strength and hardness. On the other hand, a block copolymer of such a structure that more than 90 %, particularly 100 %, by weight of the vinyl aromatic compound are used to form the homopolymer block can ~.
no more be called a useful resin, because of inferior mechanical properties, particularly inferior elongation~
inferior impact strength and a high clouding under bending stress. In a block copolymer having two or more homopolymer blocks in a molecule, the sum of vinyl aromatic monomer used in each homopolymer block should be 50 to 90 % by weight of the total vinyl aromatic monomer.
Further, in the present process, in order to form the aforesa.id random copolymer block, there is adopted a method in which a monomer mixture of a. fixed composition comprising the vinyl aromatic compound and the conjugated diene in a weight ratio from 0.1 to 3.0 1 is con-tinuously adcled. If the ratio between the vinyl aromatic compound and the conjugated d:iene is below the lower limit of the above-noted range, the impact strength among mechanical properties of the block copolymer resin formed becomes decreased and the clouding under bending s-tress becomes increased, while if the ra.tio is above the upper limit, -the tensile strength and hardness of the block copolymer resin formed become inferior, both cases being undesirable.
In the case of a block copolymer ha.ving two or more random copolymer blocks of the vinyl aromatic compound and the conjugated diene in a molecule, it is necessary to maintain the ratio between the vinyl aroma.tic compound and the conjugated diene within the above-said range from 0.1 to 3.0 in each of the copolymer blocks and also in copolymer blocks as a whole; the said fixed ratio in each of the copolymer blocks may be either the sam.e or different within the said range so long as the above-mentioned conditions are satisfied.
In forming the random copolymer block by continuously feeding a vinyl aromatic compound and a conjugated diene~ both monomers can be fed either in a mixture or separately to the polymerization system, while maintaining a fixed monomer ratio within the aforesaid range. In either case, it is necessary to feed the vinyl aromatic compound and the conjugated.
diene, in a fixed ratio, continuously to the polymeri-zation system under such conditions of tempera.ture and feeding rate tha.t both monomers will not accumulate in the sy.stem. It is also feasible to feed the vinyl ~96 51~
l aromatic compound and the conju~a-ted dicne~ while mai.ntaining the fixed monomer ra.tio, semi-consecu-tively to the polymerization system in a manner substantially approximating the continuous feeding. The above-said con-tinuous feeding is one of the charac-teristic features of the present process, which allows effective removal of a large quantity of heat generated from the polymerization reaction when carried out commercially and, moreover, preventing side reactions such as gelation accompanying the heat generation.
Although the block copolymer formed by the present process has no restriction placed on its .
structure so long as the conditions mentioned in the foregoing are satisfied, examples of particularly preferred structures are given below, wherein Sl, S2 and S3 represent homopolymer bloc~s of a vinyl a.romatic compound and (S/B)l and (S/B)2 represent copolymer bloc~s of a vinyl aromatic compound and a conjuga-ted di.ene. : .
1) Sl - (S/B)
2) Sl - (S/B)l - Sl
3) Sl - (S/B)l - S2
4) Sl - (S/B)l - (S/B)2 - S2
5) Sl - (S/B)l - S2 ~ (S/B)2
6) Sl - (S/B)l - S2 ~ (S/B)2 3
7) Sl ~ (S/B)l - (S/B)2 - (S/B)l - Sl The process of this invention is carried out by the method of multistage polymerization. In ea.ch stage, addition of the monomer may be conducted at any time after the conversion in the preceding stage has 36~
reached practically lOO %. In the present process, i-t is possible to obtain an overall conversion of subs-tcmtially 100 ~.
In the present process, the mean molecular 5 weight of copolymer resin formed is regulated by the quan-tity of an ini-tiator used. According -to this invention, the block copolymer resin should have a mean molecular weight of 0.35 to 1.8 d~g in terms of intrinsic viscosity, [ ~ ], as measured in toluene 10 solvent at 30C. A blocl~ copolymer resin of low molecular weight having an intrinsic viscosity below 0.35 dQ/g is undesirable because of decreased mechanical properties. On the other hand, a resin of excessively high molecular weight having an intrinsic viscosity 15 exceeding 1.8 de/g is also undesirable because of deteriorated transparency and processability.
The polymerization according -to this invention is carried out at -20C to 150C, preferably 20C to 120C. The pressure is selected from those which are 20 sufficient to keep the monomer and solvent in liquid phase at the polymerization temperature. The sufficient polymerization time is 1 to 48 hours, usually 2 to 24 hours, though depending on polymerization conditionsO
After -the polymerization is completed, to the 25 polymerization mixture, is added sufficient amount of water, methanol, or isopropanol to deactivate the active end of the polymer and the residua] ini-tiator, then, if necessary, a small amount of an antioxidant such as, for exarnple, 4-meth-yl-2,6-di-tert-butylphenol, and 30 thereafter an excess of methanol or isopropanol to 968~
1 precipitate and recover the polymer. ~n al-ternative procedure is to recover the polymer by clirectly heating the polymerization mixture to dryness or by contacting the polyrneriæa-tion mix-ture wi-th stea,m to ~emove the solvent by distilla-tion.
The block copolymer obtained a,ccording to this invention ma,y be processed by customary methods and used in the fields where conventional resins have been used. The copolymer can also be compounded in a known manner with conventional stabilizers, reinforcing agents, fillers, and various other additives.
As mentioned in the foregoing, the present invention provides a novel process for producing a trans-parent copolymer resin with excellent mechanical pro-perties from 90 to 65 parts by weight of a vinyl aromaticcompound monomer and 10 to 35 parts by weight of a conju-gated diene monomer, bo-th used as starting materials, by adding to the polymerization system said monomers in specified sequence and in specified combinations using ; 20 an organolithium compound as initiator. The present process may be easily carried out on a commercial scale and the resin obtained is characterized by excellent transparency and excellent mechanical properties so that it can be used even in the field where conventional resins could not be used with satisfactory results.
The invention is illustra-ted below with reference to Examples, but the invention is not limited by the Exarnples. ~`
Example 1 Into a 2.5-liter glass autoclave, af`ter having ,
reached practically lOO %. In the present process, i-t is possible to obtain an overall conversion of subs-tcmtially 100 ~.
In the present process, the mean molecular 5 weight of copolymer resin formed is regulated by the quan-tity of an ini-tiator used. According -to this invention, the block copolymer resin should have a mean molecular weight of 0.35 to 1.8 d~g in terms of intrinsic viscosity, [ ~ ], as measured in toluene 10 solvent at 30C. A blocl~ copolymer resin of low molecular weight having an intrinsic viscosity below 0.35 dQ/g is undesirable because of decreased mechanical properties. On the other hand, a resin of excessively high molecular weight having an intrinsic viscosity 15 exceeding 1.8 de/g is also undesirable because of deteriorated transparency and processability.
The polymerization according -to this invention is carried out at -20C to 150C, preferably 20C to 120C. The pressure is selected from those which are 20 sufficient to keep the monomer and solvent in liquid phase at the polymerization temperature. The sufficient polymerization time is 1 to 48 hours, usually 2 to 24 hours, though depending on polymerization conditionsO
After -the polymerization is completed, to the 25 polymerization mixture, is added sufficient amount of water, methanol, or isopropanol to deactivate the active end of the polymer and the residua] ini-tiator, then, if necessary, a small amount of an antioxidant such as, for exarnple, 4-meth-yl-2,6-di-tert-butylphenol, and 30 thereafter an excess of methanol or isopropanol to 968~
1 precipitate and recover the polymer. ~n al-ternative procedure is to recover the polymer by clirectly heating the polymerization mixture to dryness or by contacting the polyrneriæa-tion mix-ture wi-th stea,m to ~emove the solvent by distilla-tion.
The block copolymer obtained a,ccording to this invention ma,y be processed by customary methods and used in the fields where conventional resins have been used. The copolymer can also be compounded in a known manner with conventional stabilizers, reinforcing agents, fillers, and various other additives.
As mentioned in the foregoing, the present invention provides a novel process for producing a trans-parent copolymer resin with excellent mechanical pro-perties from 90 to 65 parts by weight of a vinyl aromaticcompound monomer and 10 to 35 parts by weight of a conju-gated diene monomer, bo-th used as starting materials, by adding to the polymerization system said monomers in specified sequence and in specified combinations using ; 20 an organolithium compound as initiator. The present process may be easily carried out on a commercial scale and the resin obtained is characterized by excellent transparency and excellent mechanical properties so that it can be used even in the field where conventional resins could not be used with satisfactory results.
The invention is illustra-ted below with reference to Examples, but the invention is not limited by the Exarnples. ~`
Example 1 Into a 2.5-liter glass autoclave, af`ter having ,
8~
1. been flushed wi-th argon to repla.ce the air, were cha.rged 1.5 liters of purified, dried and dea.erated cyclohexane, 0.9 g of tetrahydrofuran, and 250 g of purified and dried styrane. Into the autocla.ve was added dropwise a n-butyllithium solution in hexane until orange color characteristic of the polystyrylli-thium active end appeared (which corresponded to 2.1 millimoles) and then followed by 4.0 millimoles of n-butyllithium.
The temperature of the autocla.ve was elevated to 60C
and stirring was continued for 3 hours. A monomer mixture comprising 150 g of styrene and 100 g of purified and dried 1,3-butadiene was added under an argon pressure into the autoclave over a period of 2 hours at a cons-tant rate to continue the polymeriza-tion at 60C. After further 2 hours of polymeriza.tion~50 mQ of methanol was a.dded to the polymerization system to termina-te the polymerization. The resulting polymerization mixture was pourd into methanol contain-ing 4-methyl-2~6-di-tert-butylphenol as an antioxidant, to precipitate the polymeriza.te. The precipitated polymerizate was collected by filtra.tion and dried in vacuo to obtain a copolymer in a yield of 99.4 %.
The copolymer had an intrinsic viscosity, [q~], of o.84 d ~g, as measured in toluene at 30C. To 100 parts by weight of the copolymer, was added an antioxidan-t mixture comprising 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 par-t by weight of tris-(nonylphenyl) phosphite. The mixture was pelletized by means of an extruder and the resulting pellets were injection-molded to prepare specimens for testing 1 physical properties. The molded specimen showed beautiful apperance and was highly -transparent. The results of tes-ts for physical properties conducted on the moded specimens were as shown in Table 1.
Table 1 _ Intrinsic viscosity 1) (d~/g) o.84 Melt index 2) (g/10 minutes) 0.09 Tensile strength 3) (Xg/cm2) 312 Elongation 3) (~) 59 Izod impact strength 4) (~g-cm/cm2) notched 2.2 ~ unnotched 25.4 Haze value 5) (%) 6.0 Note: -1) Measured in toluene at 30C by means of an Ubbelohde viscometer on the copolymer before being pelletized.
2) Measured according to the method of JIS K 6760.
3) Measured according to the method of JIS K 6871, at 20C, tensile rate being 5 mm/min.
4) Measured at 20C according to the method of JIS K 6871.
5) Measured according to the method of ASTM D 1003.
Example 2 Polymeriza-tion was carried out by using the same autoclave as in Example 1 and in the same manner ~ !
as in Exampl~ 1, except that the monomer charge was as g6~
1 shown below. The inltiator used was 5.0 mi]limoles of n-butyllithium and 0.9 g of tetrahydrofuran was added.
Eirst sta.ge monomer : sl;yrene 125 g Second stage monomer:
styrene 125 g ~
Mixture 1,3-butadiene 125 g Third s-tage monomer : styrene 125 g The first stage polymerization was conducted for 2 hours. In the second stage, the monomer mixture was added at a constant rate over a period of 2 hours and the polymerization was continued for another 2 hours.
In the third stage, polymerization was conducted for further 2 hours after a.ddition of the monomer. The polymeriza.tion was terminated after 8 hours of polymeri-zation in -total. The polymerizate was treated in a manner similar to tha.t in Example 1 to obtain a copolymer in a yield of 99.8 %. The physical properties of the copolymer measured in the sa.me manner as in Example 1 were as shown in Table 2.
Table 2 Intrinsic viscosity (d~/g) 0.70 Melt index (g/10 min.) 2.1 Tensile strength (kg/cm2) Yield point. 1~0 Break point 220 : Elongation (%) 260 Izod impact strength (kg-cm/cm2) unnotched > 100 llaze va.lue (%) 8.o :
1 Examples 3 -to 7 Polymerization was carried out in the same mc~nner as in Example 2, excep:t that the monomer combinations were as shown in Table 3. As a Lewis base compo~md, each 0.9 g of tetrahydrofuran was used.
6~3~
_Fj l __ ~
j r~l r j ~
C~ r-l rc) (~1 It ~ ~ .... ~
h O C) _ O O
~ t~O t~O ~10 ~ ~ ~ ~ 5 a) o ~ o -~ O -1 P:; rl V~ rl u~ rl U~
~ ,~ ~, h ~ h rd h ~
1 ~ r~ 1~ ~I
_ _ t~O tlO tlO t~O tlO
a~
tlO O O O Ir~ O
~ F~ ~ ~ ~ C\l 1~ r~ r-lr-l r~ r~
o a~ o o o a r~
rl ~ ~ ~ h h h E-l ~ +~ ~ +' ~
~ ~ ~ U~ ~q ~U~
_ _ ~_ ~1 tlO t~O tlO tlO
r~ ~lS~ tlO tlO tlO tlO ~lS\ tlO tlO
Q N C~ O O ~lr~ C~i C~ O O
O r-l CO O O 1~ C\~l r~ ~) l~)S\
E I tlO r~ r-l r~ r~ r~ r~ r I
h ~ .
u, ~ a) a)o (D O
O ~ ~ ~ ~ ~
O rl rlrl rl rl O ~ ~ ~rc~ ~ ~
~ ~ ~ a) ~ ~ ~ a) -1~ a) ~
CQ ~ ~; ~ ~!~ ~ ~ ~ ~ :~
~P~ ~ ~m ~I:q ~
F~ I h Ih I h U:2 r~ u~ r-l U~ ~1 V2 r-l on r~
_ a) tlO tlO tlO tlO tlO
tlO O O O ~S\ O
C~l G) r-l r~r~ r-l r~
u) ~i o a) ~ a) a) a ,-~ r~ ~ r~ r~ S~
h ~ h h h h h ~rl h u~ u~ u~ _~
r-l ~1 ~ ~f) ~ ~ ~D C-h .
_ _ - :L7 -1 Ph~rsica.l proper-ties of the copolymers after having been treated in -the same manner as in Example 1 were as shown in Table 4.
g6~
- -~ i) I ~ h u~ ~ ai a) ~, ~ ~ u~
h i h E~
c~ Oi O~
~ ,r,, a) c) o O O O
El~\ o o o ~ o rl t~ r-ir-i ~1 ~ r I
rd ~ O A /\~ /\ A
H u~ _~
r~ rl ~ ~ OCO C~ ~ ~-O ~ r-i (~ ~ ~ CO
rI ~ ri r-i ri N r-i ~ ~ ~O _ a) r i ~ ~ r~ O ~ c~CO
E I b.O O rl 0~ C~ (~
~ h o N N N r-i N
h N ~i P~
+~
a) bD
r~ ~ ~
ri ~~r i ~ O ~ ~)C~ r-i iJ~ a) ri r i r-i ~) N
~ ~1 ~ N N N N
C~
~ri ~
V~ ri ~~
~ D Nr~)~1 ~1 0 ~ O O OCO r-i h C~ '~. . . . . .
rdr~l~1 0~i ri ~~
_ ~ ' .
r i ~ ~;
r~l 68~
1 Example ~
In a manner simllar to -tha-t in Example 2, four-stage polymerization was carried out by using the same apparatus as in Example 1 and a monomer combination shown below.
Firs-t stage monomer : styrene 125 g Second s-tage monomer:
styrene 105 g ~
~ mixture 1,3-butadiene 75 g J
Third stage monomer :
: styrene 20 g ~
mixture 1~3-butadiene 50 g ) Fourth sta.ge monomer: styrene 125 g ~ .
Duration of monomer addition and polymeriza- ~: :
tion period were as follows:
First stage, polymerization period : 2 hours : Second stage, Duration of monomer addition : 2 hours Polymeriza.tion period after addition of monomer : 2 hours Third stage, Duration of monomer addition : 1 hour Polymerization period after addition of monomer : 1 hour Fourth stage, polymerization period: 2 hours ' Physica.1 properties of the copolymer after : having been treated in the same manner as in Examp].e 1 were as shown in Table 5.
- 20 _ 68~
Table 5 Intrinsic viscosity (d~/g) 0.61 Melt index (g/10 minu-tes) 7.9 Tensile streng-th (kg/cm~) Yield point 127 Break point 202 Elongation (5~) 293 Izod impact strength (kg-cm/cm2) unnotched > 100 Haze value (5~) 7.5 1 Comparative Examples 1 to 4 Polymerization was carried out in the same manner as in Example 2, except that the combinations of the monomer with the Lewis base compound were as shown in Table 6.
6~
_ _ _ .
a) S ~ ~0 r-l O r ( O
~1 rd ~1~ r I ~¦ r-l R
o rd ~ Ul Ul ~ ~rl ~ ~rl ~ U~ h ~1 1~ -1 O ~ . O O ~d ~ rd ~rl a) r~ ,C' ,S:' rd rd ~ i ~ ~ ) ~ ~
h ~ ~\J (\l 'C n~ '~ ~
O ~
R ~rl a) o ~ I ~o u~ rd ~ ~ c~\
rQ ~ ~ O r >~ O
~r R l +~ h a) c, o ~ o : ' ', b O ~0 b O t,o ~0 O O O O
h O O Ir ~ a) c\~ C~l r i r l U~ ~R
o a) ~a) ~
h O o a) O O
~rl R i I ~1$~1 h ~DH
~'2 U2CQ C~
r-l _ _ rn ~10 ~0~0 ~D ~0 bD ' ' E~ O Oo o o o O OO O O O
O r~ r~r~ r I r~ r~
a~ h o a)a) o ~r~
U~ R a) a)a, a) ~rl ~rlO ~rl O ~rl ~d ~ rC:~ ~~ ~ r~ rd o ~ ~o ~ a O R ~ ~~1 ~
1~ ~5~ ~ h CQ l lU~ I ~Q I
~ ~f~ ~
r~ r~r-l r I
(D ~0 t~Ot,O ~13 ~0 O O O O
~1 O O ~ lr~
O C\~ (~Ir~ r l U~ R
o a) a~ a) ~
.~ ~ .-~ ~ ~ ~ ~
U~ oa~ a) ~ a) h ~R l ~ ~ ~
U~ U~ Cl:l U~
_ ~rl r~
Q~
h ~ O r l C\l ~1 O
1 ~s for the mode of polymerization, in Comparative Examples No. 1 and No. 2, only 1,3-butadiene was used in the second stage and it was added at a constant ra-te over a period of 2 hours, whereas in Comparative Examples No. 3 and No. 4~ a mix-ture of styrene and 1,3-butadiene was added all at a time, resulting in pronounced evolution of the heat of polymerization; in Compartive Example No. 4, polymeri-zation temperature became uncon-trollable and reached a temperature as high as about 90C.
Physical properties of the copolymers after having been treated in the same manner as in Example 1 were as shown in Table 7.
Table 7 . ' ' Compara- Intrin- Tensile Elon- Izod impact tive sic vis- streng- gation strength Trans-Example cosity th (unnotched) parency No. (d~/g) (kg/cm2) (~) (kg.cm/cm2) 1 0.72 334 12 13.0pTraranent 2 o.78 33 16 12.5 "
3 o.85 310 45 15.5 "
4 0.72 302 195 25.5 :
As is apparent from the results obtained in Comparative Examples 1 and 2, physical properties of the resulting copolymer were inferior when only 1,3-butadiene was polymerized in the second stage.
Similar results were obtained even when a mixture Or styrene and 1,3-butadiene was added in -the second stage~
,,, ~ .
.
6~36 1 provk~ed that the a Lewis base compouncl was absent, as in Comparative F.xample 3. On the c,ther hand, when a mix-ture of styrene and 1,3-bul;adiene was added all at a time in the presence of a Lewis base compound, as in Compara-tive Example 4, the polymeriza-tion temperature became uncontrollable, as sta-ted above, on account of the heat of polymerization and the physical properties of the copolymer were different from those obtained in Example 4 in Izod impact strength.
Example 9 Into a 2.5-liter glass autoclave, after having been flushed with argon to replace -the air, were charged 1.5 liters of cyclohexane and 150 g of styrene, both of which had been purified, dried, and deaerated. Into the stirred autoclave, was added dropwise n-butyIlithium, diluted with n-hexane solvent to a predetermined concentration, until faint orange color is developed in the mixture (which corresponded to 0.9 millimole) and then followed by further 6.5 millimoles of n-butyllithium as initiator. The temperature of theautoclave was elevated to 100C and stirring was continued for one hour. A monomer mixture comprising 100 g of styrene and 100 g of purified and dried 1,3-butadiene was added under an argon pressure continuously into the polymerization system at a constant rate over a period of 3 hours. After the addition, stirring was continued for 30 minutes. Then, -to the mixture was added further 150 g of styrene and allowed to polymerize at 100C for one hour. Then, 50 mR of methanol was added to terminate the polymeriza-tion. The resulting _ 2~
1. been flushed wi-th argon to repla.ce the air, were cha.rged 1.5 liters of purified, dried and dea.erated cyclohexane, 0.9 g of tetrahydrofuran, and 250 g of purified and dried styrane. Into the autocla.ve was added dropwise a n-butyllithium solution in hexane until orange color characteristic of the polystyrylli-thium active end appeared (which corresponded to 2.1 millimoles) and then followed by 4.0 millimoles of n-butyllithium.
The temperature of the autocla.ve was elevated to 60C
and stirring was continued for 3 hours. A monomer mixture comprising 150 g of styrene and 100 g of purified and dried 1,3-butadiene was added under an argon pressure into the autoclave over a period of 2 hours at a cons-tant rate to continue the polymeriza-tion at 60C. After further 2 hours of polymeriza.tion~50 mQ of methanol was a.dded to the polymerization system to termina-te the polymerization. The resulting polymerization mixture was pourd into methanol contain-ing 4-methyl-2~6-di-tert-butylphenol as an antioxidant, to precipitate the polymeriza.te. The precipitated polymerizate was collected by filtra.tion and dried in vacuo to obtain a copolymer in a yield of 99.4 %.
The copolymer had an intrinsic viscosity, [q~], of o.84 d ~g, as measured in toluene at 30C. To 100 parts by weight of the copolymer, was added an antioxidan-t mixture comprising 0.5 part by weight of 4-methyl-2,6-di-tert-butylphenol and 0.5 par-t by weight of tris-(nonylphenyl) phosphite. The mixture was pelletized by means of an extruder and the resulting pellets were injection-molded to prepare specimens for testing 1 physical properties. The molded specimen showed beautiful apperance and was highly -transparent. The results of tes-ts for physical properties conducted on the moded specimens were as shown in Table 1.
Table 1 _ Intrinsic viscosity 1) (d~/g) o.84 Melt index 2) (g/10 minutes) 0.09 Tensile strength 3) (Xg/cm2) 312 Elongation 3) (~) 59 Izod impact strength 4) (~g-cm/cm2) notched 2.2 ~ unnotched 25.4 Haze value 5) (%) 6.0 Note: -1) Measured in toluene at 30C by means of an Ubbelohde viscometer on the copolymer before being pelletized.
2) Measured according to the method of JIS K 6760.
3) Measured according to the method of JIS K 6871, at 20C, tensile rate being 5 mm/min.
4) Measured at 20C according to the method of JIS K 6871.
5) Measured according to the method of ASTM D 1003.
Example 2 Polymeriza-tion was carried out by using the same autoclave as in Example 1 and in the same manner ~ !
as in Exampl~ 1, except that the monomer charge was as g6~
1 shown below. The inltiator used was 5.0 mi]limoles of n-butyllithium and 0.9 g of tetrahydrofuran was added.
Eirst sta.ge monomer : sl;yrene 125 g Second stage monomer:
styrene 125 g ~
Mixture 1,3-butadiene 125 g Third s-tage monomer : styrene 125 g The first stage polymerization was conducted for 2 hours. In the second stage, the monomer mixture was added at a constant rate over a period of 2 hours and the polymerization was continued for another 2 hours.
In the third stage, polymerization was conducted for further 2 hours after a.ddition of the monomer. The polymeriza.tion was terminated after 8 hours of polymeri-zation in -total. The polymerizate was treated in a manner similar to tha.t in Example 1 to obtain a copolymer in a yield of 99.8 %. The physical properties of the copolymer measured in the sa.me manner as in Example 1 were as shown in Table 2.
Table 2 Intrinsic viscosity (d~/g) 0.70 Melt index (g/10 min.) 2.1 Tensile strength (kg/cm2) Yield point. 1~0 Break point 220 : Elongation (%) 260 Izod impact strength (kg-cm/cm2) unnotched > 100 llaze va.lue (%) 8.o :
1 Examples 3 -to 7 Polymerization was carried out in the same mc~nner as in Example 2, excep:t that the monomer combinations were as shown in Table 3. As a Lewis base compo~md, each 0.9 g of tetrahydrofuran was used.
6~3~
_Fj l __ ~
j r~l r j ~
C~ r-l rc) (~1 It ~ ~ .... ~
h O C) _ O O
~ t~O t~O ~10 ~ ~ ~ ~ 5 a) o ~ o -~ O -1 P:; rl V~ rl u~ rl U~
~ ,~ ~, h ~ h rd h ~
1 ~ r~ 1~ ~I
_ _ t~O tlO tlO t~O tlO
a~
tlO O O O Ir~ O
~ F~ ~ ~ ~ C\l 1~ r~ r-lr-l r~ r~
o a~ o o o a r~
rl ~ ~ ~ h h h E-l ~ +~ ~ +' ~
~ ~ ~ U~ ~q ~U~
_ _ ~_ ~1 tlO t~O tlO tlO
r~ ~lS~ tlO tlO tlO tlO ~lS\ tlO tlO
Q N C~ O O ~lr~ C~i C~ O O
O r-l CO O O 1~ C\~l r~ ~) l~)S\
E I tlO r~ r-l r~ r~ r~ r~ r I
h ~ .
u, ~ a) a)o (D O
O ~ ~ ~ ~ ~
O rl rlrl rl rl O ~ ~ ~rc~ ~ ~
~ ~ ~ a) ~ ~ ~ a) -1~ a) ~
CQ ~ ~; ~ ~!~ ~ ~ ~ ~ :~
~P~ ~ ~m ~I:q ~
F~ I h Ih I h U:2 r~ u~ r-l U~ ~1 V2 r-l on r~
_ a) tlO tlO tlO tlO tlO
tlO O O O ~S\ O
C~l G) r-l r~r~ r-l r~
u) ~i o a) ~ a) a) a ,-~ r~ ~ r~ r~ S~
h ~ h h h h h ~rl h u~ u~ u~ _~
r-l ~1 ~ ~f) ~ ~ ~D C-h .
_ _ - :L7 -1 Ph~rsica.l proper-ties of the copolymers after having been treated in -the same manner as in Example 1 were as shown in Table 4.
g6~
- -~ i) I ~ h u~ ~ ai a) ~, ~ ~ u~
h i h E~
c~ Oi O~
~ ,r,, a) c) o O O O
El~\ o o o ~ o rl t~ r-ir-i ~1 ~ r I
rd ~ O A /\~ /\ A
H u~ _~
r~ rl ~ ~ OCO C~ ~ ~-O ~ r-i (~ ~ ~ CO
rI ~ ri r-i ri N r-i ~ ~ ~O _ a) r i ~ ~ r~ O ~ c~CO
E I b.O O rl 0~ C~ (~
~ h o N N N r-i N
h N ~i P~
+~
a) bD
r~ ~ ~
ri ~~r i ~ O ~ ~)C~ r-i iJ~ a) ri r i r-i ~) N
~ ~1 ~ N N N N
C~
~ri ~
V~ ri ~~
~ D Nr~)~1 ~1 0 ~ O O OCO r-i h C~ '~. . . . . .
rdr~l~1 0~i ri ~~
_ ~ ' .
r i ~ ~;
r~l 68~
1 Example ~
In a manner simllar to -tha-t in Example 2, four-stage polymerization was carried out by using the same apparatus as in Example 1 and a monomer combination shown below.
Firs-t stage monomer : styrene 125 g Second s-tage monomer:
styrene 105 g ~
~ mixture 1,3-butadiene 75 g J
Third stage monomer :
: styrene 20 g ~
mixture 1~3-butadiene 50 g ) Fourth sta.ge monomer: styrene 125 g ~ .
Duration of monomer addition and polymeriza- ~: :
tion period were as follows:
First stage, polymerization period : 2 hours : Second stage, Duration of monomer addition : 2 hours Polymeriza.tion period after addition of monomer : 2 hours Third stage, Duration of monomer addition : 1 hour Polymerization period after addition of monomer : 1 hour Fourth stage, polymerization period: 2 hours ' Physica.1 properties of the copolymer after : having been treated in the same manner as in Examp].e 1 were as shown in Table 5.
- 20 _ 68~
Table 5 Intrinsic viscosity (d~/g) 0.61 Melt index (g/10 minu-tes) 7.9 Tensile streng-th (kg/cm~) Yield point 127 Break point 202 Elongation (5~) 293 Izod impact strength (kg-cm/cm2) unnotched > 100 Haze value (5~) 7.5 1 Comparative Examples 1 to 4 Polymerization was carried out in the same manner as in Example 2, except that the combinations of the monomer with the Lewis base compound were as shown in Table 6.
6~
_ _ _ .
a) S ~ ~0 r-l O r ( O
~1 rd ~1~ r I ~¦ r-l R
o rd ~ Ul Ul ~ ~rl ~ ~rl ~ U~ h ~1 1~ -1 O ~ . O O ~d ~ rd ~rl a) r~ ,C' ,S:' rd rd ~ i ~ ~ ) ~ ~
h ~ ~\J (\l 'C n~ '~ ~
O ~
R ~rl a) o ~ I ~o u~ rd ~ ~ c~\
rQ ~ ~ O r >~ O
~r R l +~ h a) c, o ~ o : ' ', b O ~0 b O t,o ~0 O O O O
h O O Ir ~ a) c\~ C~l r i r l U~ ~R
o a) ~a) ~
h O o a) O O
~rl R i I ~1$~1 h ~DH
~'2 U2CQ C~
r-l _ _ rn ~10 ~0~0 ~D ~0 bD ' ' E~ O Oo o o o O OO O O O
O r~ r~r~ r I r~ r~
a~ h o a)a) o ~r~
U~ R a) a)a, a) ~rl ~rlO ~rl O ~rl ~d ~ rC:~ ~~ ~ r~ rd o ~ ~o ~ a O R ~ ~~1 ~
1~ ~5~ ~ h CQ l lU~ I ~Q I
~ ~f~ ~
r~ r~r-l r I
(D ~0 t~Ot,O ~13 ~0 O O O O
~1 O O ~ lr~
O C\~ (~Ir~ r l U~ R
o a) a~ a) ~
.~ ~ .-~ ~ ~ ~ ~
U~ oa~ a) ~ a) h ~R l ~ ~ ~
U~ U~ Cl:l U~
_ ~rl r~
Q~
h ~ O r l C\l ~1 O
1 ~s for the mode of polymerization, in Comparative Examples No. 1 and No. 2, only 1,3-butadiene was used in the second stage and it was added at a constant ra-te over a period of 2 hours, whereas in Comparative Examples No. 3 and No. 4~ a mix-ture of styrene and 1,3-butadiene was added all at a time, resulting in pronounced evolution of the heat of polymerization; in Compartive Example No. 4, polymeri-zation temperature became uncon-trollable and reached a temperature as high as about 90C.
Physical properties of the copolymers after having been treated in the same manner as in Example 1 were as shown in Table 7.
Table 7 . ' ' Compara- Intrin- Tensile Elon- Izod impact tive sic vis- streng- gation strength Trans-Example cosity th (unnotched) parency No. (d~/g) (kg/cm2) (~) (kg.cm/cm2) 1 0.72 334 12 13.0pTraranent 2 o.78 33 16 12.5 "
3 o.85 310 45 15.5 "
4 0.72 302 195 25.5 :
As is apparent from the results obtained in Comparative Examples 1 and 2, physical properties of the resulting copolymer were inferior when only 1,3-butadiene was polymerized in the second stage.
Similar results were obtained even when a mixture Or styrene and 1,3-butadiene was added in -the second stage~
,,, ~ .
.
6~36 1 provk~ed that the a Lewis base compouncl was absent, as in Comparative F.xample 3. On the c,ther hand, when a mix-ture of styrene and 1,3-bul;adiene was added all at a time in the presence of a Lewis base compound, as in Compara-tive Example 4, the polymeriza-tion temperature became uncontrollable, as sta-ted above, on account of the heat of polymerization and the physical properties of the copolymer were different from those obtained in Example 4 in Izod impact strength.
Example 9 Into a 2.5-liter glass autoclave, after having been flushed with argon to replace -the air, were charged 1.5 liters of cyclohexane and 150 g of styrene, both of which had been purified, dried, and deaerated. Into the stirred autoclave, was added dropwise n-butyIlithium, diluted with n-hexane solvent to a predetermined concentration, until faint orange color is developed in the mixture (which corresponded to 0.9 millimole) and then followed by further 6.5 millimoles of n-butyllithium as initiator. The temperature of theautoclave was elevated to 100C and stirring was continued for one hour. A monomer mixture comprising 100 g of styrene and 100 g of purified and dried 1,3-butadiene was added under an argon pressure continuously into the polymerization system at a constant rate over a period of 3 hours. After the addition, stirring was continued for 30 minutes. Then, -to the mixture was added further 150 g of styrene and allowed to polymerize at 100C for one hour. Then, 50 mR of methanol was added to terminate the polymeriza-tion. The resulting _ 2~
9!6~6 1 polymerii:ation mixture was poured into methanol con-taining 4-methy]-2,6-di-tert-butylphenol as antioxidant~ to precipitate the polymerizate. The polymerizate was collected by fil-tratiorl and dried in vacuo -to obta.in a copolymer in a yield of 99.7 %.
The copolymer had an intrinsic viscosity, [ ~], of 0.64 d~/g as measured in -toluene at 30C. To 100 parts by weight of the copolymer, was added an antioxidant mixture comprising 0.5 pa.rt by weight of 4-methy]-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl) phosphite. The resulting mixture was pelletized by means of an extruder and the resulting pellets were injection-molded to prepare specimens for testing physical properties. The molded specimen showed beautiful appearance and was highly transparent.
The results of tests for physical properties conducted on the molded specimens were as shown in Table 8.
. ~
Table 8 :
Intrinsic viscosity 1) (d~/g) 0.64 Melt index 2) (g/I0 min.) 1.99 Tensile strength 3) (kg/cm2) 263 Elongation 3) (%) 279 . Izod impact strength, unnotched 4)> 100 : (kg-cm/cm ) Clouding under bending stress 5) (mm)2.8 Note : -1) Measured in toluene at 30C by means of an Ubbelohde viscometer on the copolymer before ~ 25 _ 1 being pelle-ti~ed.
2) Measured according to the method of JIS K 6760.
3) Measured according -to the method of JIS K 6871, at 20C, tensile rate being 5 mm/min.
4) Measured according to the method of JIS K 6871, at 20C on an unnotched specimen.
5) A specimen, 38 mm x 13 mm, was cut out of a press~molded sheet, 1 mm in thickness, and annealed at 80C for 3 hours. The annealed specimen, without incision, was mounted on a holder specified in JIS Z 1703, left stand-ing in the air a-t room temperature for 2~
hours, and the distance between cracks developed under bending stress was measured.
In order to confirm that the copolymer block formed by feeding a mixture of styrene and l,3-butadiene in the second stage of polymerization in Example 9 is really a substantially random copolymer, the following experiment was conducted. Under the same conditions as in Example 1, a mixture comprising 100 g of styrene and 100 g of 1,3-butadiene was added at a uniform rate into a 2.5-liter pressure reactor containing 1.5 liters of cyclohexane and 6.5 millimoles of n-butyllithium and samples were withdrawn at regular intervals during polymerization to determine the styrene-1,3-butadiene ratio in the polymer. The results obtained were as shown in Table 9.
8~
Table 9 esampline Conver- Refractlve ~Iy~
o. (hour) (~) (n3 C) block 1 o.5 15.1 1.5505 0 2 l.o 31.8 1.5525 o 3 1.5 l~9 0 1.551+0 0 4 2.0 64.8 1.5547 o 2.5 82.3 1.5551 o 6 3.0 99.2 1.5550 o 7 3.25 loO.l ].5552 o 8 3.5 100.3 1.5549 o 9 4.o loO.l 1.5550 o lNote : - -l) By oxidative decomposition.
It was found that the styrene-1,3-butadiene copolymer bloc~ formed in Example 9 is a substantially random copolymer~ as evidenced by the fact tha.t the monomer ratio by weight in the styrene-1,3-butadiene copolymer block remained practically constant at 1 : 1 independent of conversion as estimated from the refrac-tive index and that no polystyrene bloc~ was formed. :~
Examples 10 to 12 Polymerization was carried out in the samemanner as in Example 9, except that the monomer combinations and durations of continuous addition of a styrene-1,3-butadiene mixture in the second stage were 1~ as shown in Table 10.
L~9 El.C, ~ ~ f~
rl 5~
~0 ~
a) ^ ~ o ~0 ~D
~1 r~
u~ h (I) O ~1) ~ E. l r~ r~
O
r~ O O l a) o o C\l C~l ~ C~l r~ O r-l r~ ~I r i ~1 tt~ b()--` a) o ~1 ~ ~D ~ ~ ~
.,, _, a) a) a) ul rl ~rJ ~rl ~ oa) ~ a~ ~ a) ~
El c ) r~ h ~ h m h a:
~ o U~
U~ ~ U~ ~ r-l a)~ g ~ 2 tl~ ~ ~ r-l ~1 u) h O(1) a ~ ~i ~ ~ ~
~n O ~ a~ a h ~ ~ h >~
U~ U~ U~
~ ~ ~ ' ~i ~ æ r-l rr~l r-l ~1 . _ , _ 28 -,, .
~, 9~
1 Physica1 properties of the copolymers after having been treat,ed in the same manner as in Example 9 were as shown in Tab]e 11.
h u~
a) u, rd u~ ~ ~D N
bO
;d~rl (~ O
H a) .,~
c) rdN
p~,rl ,~ c) O O O
El~ c)~ O O
~rl ~D~O H H
~d ~j N~
H u2 r~ ~rl ~~ ~D L-- 1 O ~ N )s\ N
~:1 bOr~
r~ ._._ r~ ~ ~
0 ~N
H bD ~3 H ~rl ~ ~N O
Q u~ (D~Ci~ O ~
~ r~ h b.o N N N
E I a E~
. I
_~
~d~rl ~OcO N
~! coc--r~
~rl ~i ~ N
~1 r~
bO
~rl ~
01 ~rl ~~
bD ~ r-l r-l ~1 O~ ~ ~ ~O
F-l C) . . .
~7 u~ rdO O O
rl ~~
~1 0 Orl N
Z Hr Ir-l F~l _ __ ,,~
: - ~9 -8~
1 Examples 1.3 and :L4 Polymeriza.tlon was carried out in the same manner as in Example 9, except tha.t monorner conbinations were as shown in Table 13 and the continuous addition rate of monomer mix-tures in forming the styrene-1~3-butadiene copolymer block was 1 g/minute. Physical properties of the copolymers obta.ined were as shown in Table 13.
61~
_ I _ _ a~ ~- ~
tlO 1~0 . rd v~
~ ~ C\l u~ h O r-l t~O a) a) ~ . ~rl ~> F-j ~ 0 ,r ~j l ~ ~ ~ a) ~~ t ~rl ~ ~ c ~ j _ __ - O .~
O . ID C) rd(~J
hO--` O ~ ~ a) (;~ ~0 ~ ~fl (D ~ ~ 1 u~ H ~r~ ,F31 tlO ~ Fi h O a~ ~ ~ O c) ~D
~ O ~ ~ ~ rd (D ~ .
O ~ O h d hO
h O h h P~
~ ~>~ ~ I H
O O+~ ~ ~) u~ v~ .~ _ .
r-_ lr~ )~ r~ ~ S ~ r~ ~~ ~ 1~) o ,- ~ a) o bD ~D ,r ~ ~ ~ ~ ~ ~ r~
~ ~~ rl~rl ~ ~0 u~ h h O r~
C\l ~r~h m h m ~
r-l ~ O ~ I+~ I r~ ~ _~
E I u~ ~)u~ ~ O r~ ~10 r~r~ r I r~ ~rl ~ ~ 1~) 0 ~ r~ h bD N
~1 ~ E~ (D~
O O ~0 ~1 ~o, ~D a~
~0 ~r~> ~rl _~
h a) rd ~ rd a~
~d ~ ~ c~ ~ ~ rC~rl (D ~ rl O c O O h ~h ~ ~rl ~r~
~ ~. m hm o . .
O O ~ I ,L~ I ~ r~ O O
v~ c1:2 ~u~ ~ r~
r~ r~ ~ tlO
_ . ,_.
a)~- O N C~ h t~O hO 1~ ~ ~rl ~ r l r1 V~
U2 t~O r-lr l u~ h (D ~ ~rl O ~ C~ CO
Ei ~ ~ ~ rd O O
U~ O h h ~ ~rl ~
rhl '-' h ~ H >
1:'~ Ei v~ c/~
__ I
r~ ~
El O ~ ~ E~ O ~ ~
X ~_1r-l ~i r-lr I
~1 F~l _ _ __ ~_~__ _ 3 ~9~;~6 1 Compa.rative Examples 5 to 7 Polymerization was carried out in the same manner as in Examp]e 9, except that the mode of formation of styrene-1,3-hutadiene copolymer block and of 1~3-butadiene homopolymer block was as shown in Table 14.
1~496B6 t' ~, (" _ _ J
tg _~ tl.) U~ 1 i ~1 ~ f~¦ (V ~ j ~ O I ri O r I
f.. l ^~ -rlC) O ~ r~ ' r ~ r-l ~r-l ~Ci _' ri d ^-~-1 O fri 1-' 0 ~\i o r~ o r I ~ Fl ri C~ F:i rl r-l ^ h h ~d ~ C? O ~ _~V'D C~ ~V ri tV r~i h I H QV O ~?,11O r~ ~o rd rI (V ~ . t~ ~ti 0~ o r r l ~ ~ i ~ ~i 1 h fD r-l h .,~ u~u~ :: rd t~l u~ u~
Orl 'D ~n r.~i h (D ai ~
4-1 d ~d ~ r~ fD d (V rc~ '1-l d ~ c) fli r~ ~ ~ ~ . h r- Ci o ~ r !; j 'H ~ f.~i r-l u~ tl) O u~O 'D r~i O 'D rl o ri Oh h h C~ rl 'CiC ~ h -1' '? r~ ~~rl i 'Ci ri ~D d ~ 0 fD r~
tl) I fO O ~1 '' 'D Ou~ ~i r-l rl u~ ~' r~i ~d f~) o f;~ ~ rd ,s:~~ u~ h O ^ r I ~ ~ ~rl rdh i ri fDr,_~ ~ri -1' r-l ~C? S::~ H ',~j ~li COH Q O ~ H ~ r~i _ fD -` O O
W f10 O
ai--~ f~l r i J7 h ~ ~
rd r j l ~ h a ~ ta g gg r-lfD r-l r-l r-l fDai ~0 ~D fh r-l~ ~' rD fD fD
Qu~ ~rJ f-l I
aih rd fD rd E-lr i fD l ai h ai r~ fr j i ~) ri c.),, f,r! fn, q fD O I
In ~3 ,.~ fr) r-l r-l gg g O
'D ~ _ r-l f~l r-l f~ ~ ~V
u~ h fD fD fD fD
~D 'D d ~D QV
fn O h ~ h h h ~ ~ rj ~ ~
~ U2~ U~ C~
r-l ~r~
ai fD
~ti j~ ~ ~D L' O ;~
__ _ 111~9f~
1 Phys:ical properti.es of the polymers ob-tained were as sho~m in Table 1~.
fl u~ bO
rl v~ ~ O
~0 ~ ~ ., ~rl ~ ~ ~ r ~\I
r rl ~ ,~ ~1 o ~ ~, a r-l~ m _ c~
~,.c~ ~ ~ O .
~ \ o rl ~ ~I r-lr-l O h ~ 1lO /\
H u~ ~ ~ r~
I O ~>
,_1 r ~ r-l N ~ O
r~l ~1 ~0 _ ~1 (1> ~ (~.1 ~
~-I rl bO ~ ~rJ
~d ~rl ~ c) ~ O O
E~ u~ a) \ , ~ r-l ~ h 1~1) r-l E~ ~rl X ~ O
~'~ ~! ~ ~
o ~
~rl ;,~ ~ ~O 01 1~ r-l Cl o? co [~ co a~
~ O O O .~ .
I
~d ~ .. , h r-l ~ r~
V~l~
_ 311 _ ~g~
1 As is seen from Comaprative Exa.mple 5, a block copo1ymer which :La.cks in styrene homopolymer block has markedly low terlsile s-trength. As is apparent from Comparative Exa.mples 6 and 7, when the block in the second stage is formed from 1,3-butadiene alone or by adding a styrene-1,3-buta.diene mixture all at a time, the block copolymer obtained becornes low in elongation and impact strength and becomes pronounced in clouding under bending stress.
. , ' , ' .
The copolymer had an intrinsic viscosity, [ ~], of 0.64 d~/g as measured in -toluene at 30C. To 100 parts by weight of the copolymer, was added an antioxidant mixture comprising 0.5 pa.rt by weight of 4-methy]-2,6-di-tert-butylphenol and 0.5 part by weight of tris-(nonylphenyl) phosphite. The resulting mixture was pelletized by means of an extruder and the resulting pellets were injection-molded to prepare specimens for testing physical properties. The molded specimen showed beautiful appearance and was highly transparent.
The results of tests for physical properties conducted on the molded specimens were as shown in Table 8.
. ~
Table 8 :
Intrinsic viscosity 1) (d~/g) 0.64 Melt index 2) (g/I0 min.) 1.99 Tensile strength 3) (kg/cm2) 263 Elongation 3) (%) 279 . Izod impact strength, unnotched 4)> 100 : (kg-cm/cm ) Clouding under bending stress 5) (mm)2.8 Note : -1) Measured in toluene at 30C by means of an Ubbelohde viscometer on the copolymer before ~ 25 _ 1 being pelle-ti~ed.
2) Measured according to the method of JIS K 6760.
3) Measured according -to the method of JIS K 6871, at 20C, tensile rate being 5 mm/min.
4) Measured according to the method of JIS K 6871, at 20C on an unnotched specimen.
5) A specimen, 38 mm x 13 mm, was cut out of a press~molded sheet, 1 mm in thickness, and annealed at 80C for 3 hours. The annealed specimen, without incision, was mounted on a holder specified in JIS Z 1703, left stand-ing in the air a-t room temperature for 2~
hours, and the distance between cracks developed under bending stress was measured.
In order to confirm that the copolymer block formed by feeding a mixture of styrene and l,3-butadiene in the second stage of polymerization in Example 9 is really a substantially random copolymer, the following experiment was conducted. Under the same conditions as in Example 1, a mixture comprising 100 g of styrene and 100 g of 1,3-butadiene was added at a uniform rate into a 2.5-liter pressure reactor containing 1.5 liters of cyclohexane and 6.5 millimoles of n-butyllithium and samples were withdrawn at regular intervals during polymerization to determine the styrene-1,3-butadiene ratio in the polymer. The results obtained were as shown in Table 9.
8~
Table 9 esampline Conver- Refractlve ~Iy~
o. (hour) (~) (n3 C) block 1 o.5 15.1 1.5505 0 2 l.o 31.8 1.5525 o 3 1.5 l~9 0 1.551+0 0 4 2.0 64.8 1.5547 o 2.5 82.3 1.5551 o 6 3.0 99.2 1.5550 o 7 3.25 loO.l ].5552 o 8 3.5 100.3 1.5549 o 9 4.o loO.l 1.5550 o lNote : - -l) By oxidative decomposition.
It was found that the styrene-1,3-butadiene copolymer bloc~ formed in Example 9 is a substantially random copolymer~ as evidenced by the fact tha.t the monomer ratio by weight in the styrene-1,3-butadiene copolymer block remained practically constant at 1 : 1 independent of conversion as estimated from the refrac-tive index and that no polystyrene bloc~ was formed. :~
Examples 10 to 12 Polymerization was carried out in the samemanner as in Example 9, except that the monomer combinations and durations of continuous addition of a styrene-1,3-butadiene mixture in the second stage were 1~ as shown in Table 10.
L~9 El.C, ~ ~ f~
rl 5~
~0 ~
a) ^ ~ o ~0 ~D
~1 r~
u~ h (I) O ~1) ~ E. l r~ r~
O
r~ O O l a) o o C\l C~l ~ C~l r~ O r-l r~ ~I r i ~1 tt~ b()--` a) o ~1 ~ ~D ~ ~ ~
.,, _, a) a) a) ul rl ~rJ ~rl ~ oa) ~ a~ ~ a) ~
El c ) r~ h ~ h m h a:
~ o U~
U~ ~ U~ ~ r-l a)~ g ~ 2 tl~ ~ ~ r-l ~1 u) h O(1) a ~ ~i ~ ~ ~
~n O ~ a~ a h ~ ~ h >~
U~ U~ U~
~ ~ ~ ' ~i ~ æ r-l rr~l r-l ~1 . _ , _ 28 -,, .
~, 9~
1 Physica1 properties of the copolymers after having been treat,ed in the same manner as in Example 9 were as shown in Tab]e 11.
h u~
a) u, rd u~ ~ ~D N
bO
;d~rl (~ O
H a) .,~
c) rdN
p~,rl ,~ c) O O O
El~ c)~ O O
~rl ~D~O H H
~d ~j N~
H u2 r~ ~rl ~~ ~D L-- 1 O ~ N )s\ N
~:1 bOr~
r~ ._._ r~ ~ ~
0 ~N
H bD ~3 H ~rl ~ ~N O
Q u~ (D~Ci~ O ~
~ r~ h b.o N N N
E I a E~
. I
_~
~d~rl ~OcO N
~! coc--r~
~rl ~i ~ N
~1 r~
bO
~rl ~
01 ~rl ~~
bD ~ r-l r-l ~1 O~ ~ ~ ~O
F-l C) . . .
~7 u~ rdO O O
rl ~~
~1 0 Orl N
Z Hr Ir-l F~l _ __ ,,~
: - ~9 -8~
1 Examples 1.3 and :L4 Polymeriza.tlon was carried out in the same manner as in Example 9, except tha.t monorner conbinations were as shown in Table 13 and the continuous addition rate of monomer mix-tures in forming the styrene-1~3-butadiene copolymer block was 1 g/minute. Physical properties of the copolymers obta.ined were as shown in Table 13.
61~
_ I _ _ a~ ~- ~
tlO 1~0 . rd v~
~ ~ C\l u~ h O r-l t~O a) a) ~ . ~rl ~> F-j ~ 0 ,r ~j l ~ ~ ~ a) ~~ t ~rl ~ ~ c ~ j _ __ - O .~
O . ID C) rd(~J
hO--` O ~ ~ a) (;~ ~0 ~ ~fl (D ~ ~ 1 u~ H ~r~ ,F31 tlO ~ Fi h O a~ ~ ~ O c) ~D
~ O ~ ~ ~ rd (D ~ .
O ~ O h d hO
h O h h P~
~ ~>~ ~ I H
O O+~ ~ ~) u~ v~ .~ _ .
r-_ lr~ )~ r~ ~ S ~ r~ ~~ ~ 1~) o ,- ~ a) o bD ~D ,r ~ ~ ~ ~ ~ ~ r~
~ ~~ rl~rl ~ ~0 u~ h h O r~
C\l ~r~h m h m ~
r-l ~ O ~ I+~ I r~ ~ _~
E I u~ ~)u~ ~ O r~ ~10 r~r~ r I r~ ~rl ~ ~ 1~) 0 ~ r~ h bD N
~1 ~ E~ (D~
O O ~0 ~1 ~o, ~D a~
~0 ~r~> ~rl _~
h a) rd ~ rd a~
~d ~ ~ c~ ~ ~ rC~rl (D ~ rl O c O O h ~h ~ ~rl ~r~
~ ~. m hm o . .
O O ~ I ,L~ I ~ r~ O O
v~ c1:2 ~u~ ~ r~
r~ r~ ~ tlO
_ . ,_.
a)~- O N C~ h t~O hO 1~ ~ ~rl ~ r l r1 V~
U2 t~O r-lr l u~ h (D ~ ~rl O ~ C~ CO
Ei ~ ~ ~ rd O O
U~ O h h ~ ~rl ~
rhl '-' h ~ H >
1:'~ Ei v~ c/~
__ I
r~ ~
El O ~ ~ E~ O ~ ~
X ~_1r-l ~i r-lr I
~1 F~l _ _ __ ~_~__ _ 3 ~9~;~6 1 Compa.rative Examples 5 to 7 Polymerization was carried out in the same manner as in Examp]e 9, except that the mode of formation of styrene-1,3-hutadiene copolymer block and of 1~3-butadiene homopolymer block was as shown in Table 14.
1~496B6 t' ~, (" _ _ J
tg _~ tl.) U~ 1 i ~1 ~ f~¦ (V ~ j ~ O I ri O r I
f.. l ^~ -rlC) O ~ r~ ' r ~ r-l ~r-l ~Ci _' ri d ^-~-1 O fri 1-' 0 ~\i o r~ o r I ~ Fl ri C~ F:i rl r-l ^ h h ~d ~ C? O ~ _~V'D C~ ~V ri tV r~i h I H QV O ~?,11O r~ ~o rd rI (V ~ . t~ ~ti 0~ o r r l ~ ~ i ~ ~i 1 h fD r-l h .,~ u~u~ :: rd t~l u~ u~
Orl 'D ~n r.~i h (D ai ~
4-1 d ~d ~ r~ fD d (V rc~ '1-l d ~ c) fli r~ ~ ~ ~ . h r- Ci o ~ r !; j 'H ~ f.~i r-l u~ tl) O u~O 'D r~i O 'D rl o ri Oh h h C~ rl 'CiC ~ h -1' '? r~ ~~rl i 'Ci ri ~D d ~ 0 fD r~
tl) I fO O ~1 '' 'D Ou~ ~i r-l rl u~ ~' r~i ~d f~) o f;~ ~ rd ,s:~~ u~ h O ^ r I ~ ~ ~rl rdh i ri fDr,_~ ~ri -1' r-l ~C? S::~ H ',~j ~li COH Q O ~ H ~ r~i _ fD -` O O
W f10 O
ai--~ f~l r i J7 h ~ ~
rd r j l ~ h a ~ ta g gg r-lfD r-l r-l r-l fDai ~0 ~D fh r-l~ ~' rD fD fD
Qu~ ~rJ f-l I
aih rd fD rd E-lr i fD l ai h ai r~ fr j i ~) ri c.),, f,r! fn, q fD O I
In ~3 ,.~ fr) r-l r-l gg g O
'D ~ _ r-l f~l r-l f~ ~ ~V
u~ h fD fD fD fD
~D 'D d ~D QV
fn O h ~ h h h ~ ~ rj ~ ~
~ U2~ U~ C~
r-l ~r~
ai fD
~ti j~ ~ ~D L' O ;~
__ _ 111~9f~
1 Phys:ical properti.es of the polymers ob-tained were as sho~m in Table 1~.
fl u~ bO
rl v~ ~ O
~0 ~ ~ ., ~rl ~ ~ ~ r ~\I
r rl ~ ,~ ~1 o ~ ~, a r-l~ m _ c~
~,.c~ ~ ~ O .
~ \ o rl ~ ~I r-lr-l O h ~ 1lO /\
H u~ ~ ~ r~
I O ~>
,_1 r ~ r-l N ~ O
r~l ~1 ~0 _ ~1 (1> ~ (~.1 ~
~-I rl bO ~ ~rJ
~d ~rl ~ c) ~ O O
E~ u~ a) \ , ~ r-l ~ h 1~1) r-l E~ ~rl X ~ O
~'~ ~! ~ ~
o ~
~rl ;,~ ~ ~O 01 1~ r-l Cl o? co [~ co a~
~ O O O .~ .
I
~d ~ .. , h r-l ~ r~
V~l~
_ 311 _ ~g~
1 As is seen from Comaprative Exa.mple 5, a block copo1ymer which :La.cks in styrene homopolymer block has markedly low terlsile s-trength. As is apparent from Comparative Exa.mples 6 and 7, when the block in the second stage is formed from 1,3-butadiene alone or by adding a styrene-1,3-buta.diene mixture all at a time, the block copolymer obtained becornes low in elongation and impact strength and becomes pronounced in clouding under bending stress.
. , ' , ' .
Claims (28)
1. In a process for producing a transparent block copolymer resin by block-copolymerizing 90 to 65 parts by weight of a vinyl aromatic compound monomer and 10 to 35 parts by weight of a conjugated diene monomer in a hydrocarbon solvent using an organolithium compound as initiator in the presence or absence of 0.01 to 5 mole-% based on total monomer of a Lewis base compound to form a block copolymer in which each polymer molecule has at least one plastic region comprising a homopolymer of the vinyl aromatic compound and at least one elasto-meric region comprising a copolymer of the vinyl aromatic compound and the conjugated diene, an improve-ment which comprises forming said plastic region by homopolymerizing 50 to 90 % by weight of the total vinyl aromatic compound monomer and said elastomeric region by adding continuously to the polymerization system a monomer mixture of a fixed composition, in which the weight ratio of the vinyl aromatic compound monomer to the conjugated diene monomer is 0.1 to 3.0 the resulting block copolymer having a mean molecular weight of 0.35 to 1.8 d?/g in terms of intrinsic viscosity as measured in toluene at 30°C.
2. A process according to Claim 1, wherein the vinyl aromatic compound monomer is at least one member selected from the group consisting of styrene, .alpha.-methylstyrene and vinyltoluene.
3. A process according to Claim 2, wherein the vinyl aromatic compound monomer is styrene.
4. A process according to Claim 1, wherein the conjugated diene monomer is at least one member slected from the group consisting of 1,3-butadiene, isoprene and piperylene.
5. A process according to Claim 11, wherein the conjugated diene monomer is 1,3-butadiene.
6. A process according to Claim 1, wherein the hydrocarbon solvent is at least one member selected from the group consisting of aromatic, aliphatic and alicyclic hydrocarbons.
7. A process according to Claim 6, wherein the hydrocarbon solvent is at least one member selected from the group consisting of hexane, heptane, cyclo-hexane, methylcyclohexane, benzene and toluene.
8. A process according to Claim 1, wherein the inert hydrocarbon solvent is used in a proportion of 1 to 20 parts by weight per part by weight of the total monomer.
9. A process according to Claim 1, wherein the Lewis base compound is an ether compound or a tertiary amine compound.
10. A process according to Claim 9, wherein the ether compound is one member selected from the group consisting of cyclic ethers, aliphatic monoethers and aliphatic polyethers.
11. A process according to Claim 10, wherein the ether compound is one member selected from the group consisting of tetrahydrofuran, tetrahydropyran, diethyl ether, dibutyl ether, ethylene glycol dimethyl ether and diethylene glycol diethyl ether.
12. A process according to Claim 9, wherein the tertiary amine compound is one member slected from the group consisting of triethylamine, tripropylamine, tributylamine, N,N'-dimethylaniline and pyridine.
13. A process according to Claim 1, wherein the Lewis base compound is used in a proportion of 0.01 to 5 mole-% based on the total monomer.
14. A process according to Claim 1, wherein the Lewis base compound is not used.
15. A process according to Claim 1, wherein the organolithium compound is an organomonolithium compound or an organodilithium compound.
16. A process according to Claim 15, wherein the organo-monolithium compound is at least one member selected from the group consisting of ethyllithium, propyllithium, butyllithium, amyllithium, hexyllithium, 2-ethylhexyllithium, cyclohexyllithium, decyllithium, dodecyllithium, phenyllithium, tolyllithium, xylyllitium and naphthyllithium.
17. A process according to Claim 16, wherein the organo-monolithium compound is butyllithium.
18. A process according to Claim 15, wherein the organo-dilithium compound is at least one member selected from the group consisting of trimethylene-dilithium, tetramethylene-dilithium, pentamethylene-dilithium, naphthalene-lithium complex, stilbene-lithium complex, diphenyl-lithium complex, oligobutadienyl-dilithium and oligoisoprenyl-dilithium.
19. A process according to Claim 18, wherein the organo-dilithium compound is one member selected from the group consisting of oligobutadienyl-dilithium and oligoisoprenyl-dilithium.
20. A process according to Claim 1, wherein the organolithium compound is used in a proportion of 0.002 to 5 mole-% based on the total monomer.
21. A process according to Claim 1, wherein in forming two or more plastic regions composed of homo-polymers of a vinyl aromatic compound, sum of the vinyl aromatic compound used in forming each plastic region is 50 to 90 % by weight based on the total vinyl aromatic compound monomer.
22. A process according to Claim 1, wherein in forming two or more elastomeric regions composed of random copolymers of a vinyl aromatic compound and a conjugated diene, the weight ratio of the vinyl aromatic compound to the conjugated diene used in forming each elastomeric region is in the range from 0.1 to 3.0 and the weight ratio of the vinyl aromatic compound to the conjugated diene used in forming all elastomeric regions is also in the range from 0.1 to 3Ø
23. A process according to Claim 22, wherein in forming two or more elastomeric regions by continuous addition of the vinyl aromatic compound and the conjugated diene in a fixed ratio, said ratio is different among the elastomeric regions from one another.
24. A process according to Claim 22, wherein in forming each elastomeric region, the vinyl aromatic compound and the conjugated diene are added in a fixed ratio either continuously or semi-consecutively in a manner deemed to be substantially continuous.
25. A process according to Claim 24, wherein the monomer mixture is fed under polymerization conditions at such a rate that the fed monomers may polymerize instantly and so will not accumulate in the polymerization system.
26. A process according to Claim 1, wherein the structure of the block copolymer to be formed is selected from the group consisting of (1) S1 - (S/B)1, (2) S1 - (S/B)1 - S1, (3) S1 - (S/B)1 - S2, (4) S1 - (S/B)1 - (S/B)2 - S2, (5) S1 - (S/B)1 - S2 - (S/B)2, (6) S1 - (S/B)1 - S2 - (S/B)2 - S3, and (7) S1 - (S/B)1 - (S/B)2 - (S/B)1 - S1, where S1, S2, and S3 represent homopolymer regions of a vinyl aromatic compound and (S/B)1 and (S/B)2 represent copolymer regions of a vinyl aromatic compound and a conjugated diene.
27. A process according to Claim 1, wherein the poly-merization is effected at a temperature in the range from 20°
to 120°C.
to 120°C.
28. A process according to Claim 1, wherein, after completion of the polymerization, the polymerization mixture is contacted with excess of a lower alcohol, or directly heated to dryness, or mixed with steam, thereby removing the solvent to recover the polymer.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP49006370A JPS5811446B2 (en) | 1974-01-10 | 1974-01-10 | The best way to get started |
| JP6514874A JPS50156593A (en) | 1974-06-08 | 1974-06-08 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1049686A true CA1049686A (en) | 1979-02-27 |
Family
ID=26340487
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA217,483A Expired CA1049686A (en) | 1974-01-10 | 1975-01-07 | Process for producing transparent block copolymer resin from a vinyl aromatic monomer and a conjugated diene |
Country Status (6)
| Country | Link |
|---|---|
| CA (1) | CA1049686A (en) |
| DE (1) | DE2500690C3 (en) |
| FR (1) | FR2257618B1 (en) |
| GB (1) | GB1491741A (en) |
| IT (1) | IT1026295B (en) |
| NL (1) | NL159122B (en) |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3175160D1 (en) * | 1980-09-06 | 1986-09-25 | Asahi Chemical Ind | Process for continuously polymerizing a block copolymer and the block copolymer mixture obtained therefrom |
| US5204407A (en) * | 1990-06-11 | 1993-04-20 | Bridgestone Corporation | Pneumatic tires |
| US6096828A (en) * | 1995-08-29 | 2000-08-01 | Phillips Petroleum Company | Conjugated diene/monovinylarene block copolymers, methods for preparing same, and polymer blends |
| US6835778B2 (en) | 1995-08-29 | 2004-12-28 | Chevron Phillips Chemical Company Lp | Conjugated diene/monovinylarene block copolymers blends |
| US20040115381A1 (en) * | 2002-12-12 | 2004-06-17 | Chevron Phillips Chemical Company, Lp | Method for manufacturing articles with materials containing tapered polymers |
| US9598524B1 (en) | 2015-09-18 | 2017-03-21 | Chevron Phillips Chemical Company Lp | Styrene-butadiene block copolymers with a terminal butadiene block for tubing applications |
| US9441090B1 (en) | 2015-03-12 | 2016-09-13 | Chevron Phillips Chemical Company Lp | Methods for controlling hardness of styrene-butadiene block copolymers |
| US9540475B2 (en) | 2015-03-12 | 2017-01-10 | Chevron Phillips Chemical Company Lp | Styrene-butadiene block copolymers for tubing applications |
| US9738781B2 (en) | 2015-09-03 | 2017-08-22 | Ineos Styrolution Group Gmbh | Blends of styrene-butadiene block copolymer with styrenic thermoplastic elastomers for tubing applications |
| US10023676B2 (en) | 2016-02-24 | 2018-07-17 | Ineos Styrolution Group Gmbh | Styrene-butadiene block copolymers with an internal butadiene block for tubing applications |
-
1975
- 1975-01-07 CA CA217,483A patent/CA1049686A/en not_active Expired
- 1975-01-08 NL NL7500206A patent/NL159122B/en not_active IP Right Cessation
- 1975-01-08 FR FR7500407A patent/FR2257618B1/fr not_active Expired
- 1975-01-09 DE DE19752500690 patent/DE2500690C3/en not_active Expired
- 1975-01-09 IT IT4760975A patent/IT1026295B/en active
- 1975-01-10 GB GB119075A patent/GB1491741A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| DE2500690A1 (en) | 1975-07-17 |
| FR2257618B1 (en) | 1979-06-08 |
| GB1491741A (en) | 1977-11-16 |
| DE2500690B2 (en) | 1980-01-17 |
| NL7500206A (en) | 1975-07-14 |
| FR2257618A1 (en) | 1975-08-08 |
| NL159122B (en) | 1979-01-15 |
| DE2500690C3 (en) | 1980-09-11 |
| IT1026295B (en) | 1978-09-20 |
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