JP4525398B2 - Hydrogenated aromatic vinyl copolymer composition and molded article thereof - Google Patents

Description

  The present invention relates to a hydrogenated aromatic vinyl copolymer composition and a molded article thereof, and more specifically, a hydrogenated aromatic having excellent transparency and impact resistance, low water absorption, and low birefringence. The present invention relates to a vinyl copolymer composition and a molded product thereof.

  Conventionally, various resin materials have been used as materials for constituting optical components used in various fields. In addition, in order to obtain physical properties suitable for each field, resin compositions (resin materials) in which materials and components having various structures are blended have been developed.

  Specifically, a vinylcyclohexane polymer obtained by hydrogenating an aromatic vinyl polymer is disclosed as a material for constituting an optical disk substrate (see, for example, Patent Document 1). Patent Document 1 describes that this vinylcyclohexane polymer has a high light transmittance, a low water absorption, and a low birefringence. On the other hand, a hydrogenated polymer having a specific molecular weight obtained by hydrogenating an aromatic vinyl polymer and having a hydrogenation rate of an aromatic ring of 97% or more is disclosed (for example, see Patent Document 2). Patent Document 2 describes that this hydrogenated polymer has small birefringence, excellent mechanical strength, and excellent moisture resistance.

  Further, a hydrogenated styrene copolymer obtained by hydrogenating a styrene copolymer having a specific monomer composition is disclosed (for example, see Patent Document 3). Patent Document 3 describes that this hydrogenated styrene copolymer is excellent in heat resistance and transparency and has a low water absorption rate. Furthermore, hydrogenated styrene-conjugated diene copolymers having a specific block structure or formed by hydrogenating a styrene-conjugated diene copolymer having a specific molecular weight are disclosed (for example, Patent Documents 4 to 4). 6). Patent Documents 4 to 6 describe that these hydrogenated styrene-conjugated diene copolymers are excellent in transparency, heat resistance, rigidity, and the like.

By the way, such a resin material used for constituting an optical component has high transparency, low water absorption, and exhibits excellent impact resistance during processing steps and use. is needed. That is, when the resin material is highly brittle, it is known that chipping or breakage is likely to occur at the time of molding, and it is easily broken by hitting. Therefore, a resin material for constituting an optical component is required to have excellent transparency, low water absorption, and excellent impact resistance. However, the resin materials disclosed in Patent Documents 1 to 6 are still not sufficient in terms of impact resistance, and further improvements are required.
Japanese Examined Patent Publication No. 7-114030 JP 2000-169521 A JP 2002-201213 A JP 2002-327010 A JP 2003-2938 A JP 2003-252941 A

  The present invention has been made in view of such problems of the prior art, and the object is to have excellent transparency and impact resistance, low water absorption, and low birefringence. An object of the present invention is to provide a hydrogenated aromatic vinyl copolymer composition, and a molded article having excellent transparency and impact resistance, low water absorption, and low birefringence.

  As a result of intensive studies to achieve the above-mentioned problems, the inventors of the present invention have a specific block structure in which an aromatic vinyl monomer and a conjugated diene monomer are included as constituent units in a predetermined ratio, respectively, and are partially hydrogenated. It has been found that the above problem can be achieved by hydrogenating a block copolymer composition containing two or more types of block copolymers represented, and the present invention has been completed.

  That is, according to the present invention, the following hydrogenated aromatic vinyl copolymer composition and a molded article using the same are provided.

[1] Hydrogenated aromatic vinyl-based copolymer obtained by hydrogenating a block copolymer composition containing two or more block copolymers composed of an aromatic vinyl monomer and a monomer structural unit containing a conjugated diene monomer A block copolymer satisfying the following condition (1), wherein the block copolymer composition comprises a monomer constituent unit including a first aromatic vinyl monomer and a first conjugated diene monomer. (I) and a block copolymer (II) comprising a monomer constituent unit containing a second aromatic vinyl monomer and a second conjugated diene monomer, satisfying the following condition (2): (I) / ( II) = 95/5 to 80/20 in a mass ratio, the aromatic ring derived from the first and second aromatic vinyl monomers, and the first and second conjugated dienemo 97% or more of double bonds derived from mers hydrogenated hydrogenated aromatic vinyl copolymer composition obtained.
Condition (1): The content ratio of the structural unit derived from the first aromatic vinyl monomer is 90 to 95% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the first conjugated diene monomer are hydrogenated.
Condition (2): The content ratio of the structural unit derived from the second aromatic vinyl monomer is 40 to 60% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the second conjugated diene monomer are hydrogenated.
A-B-A (1)
(In the general formula (1), A is a structural unit derived from the first or second aromatic vinyl monomer, and B is a structural unit derived from the first or second conjugated diene monomer)

  [2] The hydrogenated aromatic vinyl type according to [1], wherein the glass transition point is 120 ° C. or higher, the weight average molecular weight is 50,000 or higher, and the light transmittance of 750 nm wavelength light at a thickness of 25 mm is 88% or higher. Copolymer composition.

  [3] A molded product obtained by molding the hydrogenated aromatic vinyl copolymer composition according to [1] or [2].

  The hydrogenated aromatic vinyl copolymer composition of the present invention is excellent in transparency and impact resistance, has low water absorption, and has a small birefringence.

  In addition, the molded product of the present invention exhibits excellent effects of transparency and impact resistance, low water absorption, and low birefringence.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out the present invention will be described below, but the present invention is not limited to the following embodiment, and is based on the ordinary knowledge of those skilled in the art without departing from the gist of the present invention. It should be understood that modifications and improvements as appropriate to the following embodiments also fall within the scope of the present invention.

1. Hydrogenated aromatic vinyl-based copolymer composition One embodiment of the hydrogenated aromatic vinyl-based copolymer composition of the present invention includes two or more kinds of monomer constituent units including an aromatic vinyl monomer and a conjugated diene monomer. A hydrogenated aromatic vinyl copolymer composition obtained by hydrogenating a block copolymer composition containing the block copolymer, and a block copolymer composition (copolymer composition before hydrogenation) A block copolymer (I) comprising a monomer constituent unit containing a first aromatic vinyl monomer and a first conjugated diene monomer, satisfying the following condition (1), a second aromatic vinyl monomer, and A block copolymer (II) consisting of a monomer structural unit containing a second conjugated diene monomer and satisfying the following condition (2), at a mass ratio of (I) / (II) = 95/5 to 80/20 contains The aromatic ring derived from the first and second aromatic vinyl monomers and 97% or more of the double bond derived from the first and second conjugated diene monomers are hydrogenated. . The details will be described below. In the present specification, the term “aromatic vinyl monomer” refers to both the first aromatic vinyl monomer and the second aromatic vinyl monomer. Similarly, when simply referred to as “conjugated diene monomer”, both the first conjugated diene monomer and the second conjugated diene monomer are indicated.
Condition (1): The content ratio of the structural unit derived from the first aromatic vinyl monomer is 90 to 95% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the first conjugated diene monomer are hydrogenated.
Condition (2): The content ratio of the structural unit derived from the second aromatic vinyl monomer is 40 to 60% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the second conjugated diene monomer are hydrogenated.
A-B-A (1)
(In the general formula (1), A is a structural unit derived from the first or second aromatic vinyl monomer, and B is a structural unit derived from the first or second conjugated diene monomer)

(1) Block copolymer (I) (copolymer before nuclear hydrogenation)
The block copolymer composition, which is a pre-hydrogenation copolymer composition of the hydrogenated aromatic vinyl copolymer composition of the present embodiment, is a block copolymer (I) (nuclear hydrogenation) that satisfies a predetermined condition. A pre-copolymer). This block copolymer (I) is composed of structural units derived from monomers including a first aromatic vinyl monomer and a first conjugated diene monomer. Further, the block copolymer (I) comprises 90 to 95% by mass, preferably 90 to 94% by mass, more preferably 90 to 93% by mass of a structural unit derived from the first aromatic vinyl monomer. It is. When the proportion of the structural unit derived from the first aromatic vinyl monomer is less than 90% by mass, the total light ray of the hydrogenated aromatic vinyl copolymer composition obtained using this block copolymer (I) The transmittance decreases and it becomes difficult to ensure sufficient transparency as a material for optical components. On the other hand, if the proportion of the structural unit derived from the first aromatic vinyl monomer is more than 95% by mass, the resulting hydrogenated aromatic vinyl copolymer composition has low impact resistance.

  The block copolymer (I), which is a copolymer before nuclear hydrogenation, preferably contains 5 to 10% by mass of a structural unit derived from the first conjugated diene monomer, and 7 to 10% by mass. Is more preferable. When the proportion of the structural unit derived from the first conjugated diene monomer is less than 5% by mass, the impact resistance tends to be inferior. On the other hand, when the proportion of the structural unit derived from the first conjugated diene monomer is more than 10% by mass, the total light transmittance tends to decrease.

  The block copolymer (I), which is a copolymer before nuclear hydrogenation, has a block structure represented by the general formula (1). The hydrogenated aromatic vinyl copolymer composition of the present embodiment is obtained by converting a block copolymer composition containing two or more block copolymers having a block structure represented by a predetermined general formula into an aromatic ring. Since it is obtained by hydrogenation, it has excellent impact resistance and fluidity. The two “A” s in the general formula (1) may be the same or different in terms of the molecular weight, the type of the first aromatic vinyl monomer constituting each, and the like.

  The weight average molecular weight of the block copolymer (I) which is a copolymer before nuclear hydrogenation is 70,000 to 200,000, preferably 70,000 to 180,000, and more preferably 70,000 to 150,000. When the weight average molecular weight of the block copolymer (I) is less than 70,000, the resulting hydrogenated aromatic vinyl copolymer composition has low impact resistance. On the other hand, if the weight average molecular weight of the block copolymer (II) is more than 200,000, the fluidity of the resulting hydrogenated aromatic vinyl copolymer composition is lowered, and handling becomes difficult.

  Further, the block copolymer (I) which is a copolymer before nuclear hydrogenation is 80% or more of the double bond derived from the first conjugated diene monomer, preferably 85% or more, more preferably 90% or more, Particularly preferably, 95% or more is hydrogenated. That is, the hydrogenation rate of the block copolymer (I) is 80% or more (excluding nuclear hydrogenation). By setting the hydrogenation rate of the block copolymer (I) to 80% or more, problems such as gelation reaction caused when hydrogenating the block copolymer composition containing the block copolymer (I) are eliminated. Occurrence can be avoided.

  The block copolymer (I) is synthesized by a conventionally known method disclosed in, for example, JP-A-2-133406, JP-A-3-128957, and JP-A-5-170844. be able to.

(2) Block copolymer (II) (copolymer before nuclear hydrogenation)
The block copolymer composition, which is a pre-hydrogenation copolymer composition of the hydrogenated aromatic vinyl copolymer composition of the present embodiment, comprises a block copolymer (II) (nuclear hydrogenation) that satisfies a predetermined condition. A pre-copolymer). This block copolymer (II) consists of a structural unit derived from a monomer containing a second aromatic vinyl monomer and a second conjugated diene monomer. Further, the block copolymer (II) contains 40 to 60% by mass, preferably 47 to 58% by mass, more preferably 45 to 55% by mass of a structural unit derived from the second aromatic vinyl monomer. It is. When the proportion of the structural unit derived from the second aromatic vinyl monomer is less than 40% by mass, the total light of the hydrogenated aromatic vinyl copolymer composition obtained using this block copolymer (II) The transmittance decreases and it becomes difficult to ensure sufficient transparency as a material for optical components. On the other hand, if the proportion of the structural unit derived from the second aromatic vinyl monomer is more than 60% by mass, the resulting hydrogenated aromatic vinyl copolymer composition has low impact resistance.

  The block copolymer (II), which is a copolymer before nuclear hydrogenation, preferably contains 40 to 60% by mass of structural units derived from the second conjugated diene monomer, and contains 45 to 55% by mass. Is more preferable. When the proportion of the structural unit derived from the second conjugated diene monomer is less than 40% by mass, the impact resistance tends to be inferior. On the other hand, when the proportion of the structural unit derived from the second conjugated diene monomer is more than 60% by mass, the total light transmittance tends to decrease.

  The block copolymer (II), which is a copolymer before nuclear hydrogenation, has a block structure represented by the general formula (1). The hydrogenated aromatic vinyl copolymer composition of the present embodiment is obtained by converting a block copolymer composition containing two or more block copolymers having a block structure represented by a predetermined general formula into an aromatic ring. Since it is obtained by hydrogenation, it has excellent impact resistance and fluidity. The two “A” s in the general formula (1) may be the same or different in molecular weight, type of second aromatic vinyl monomer constituting each, and the like.

  The weight average molecular weight of the block copolymer (II) which is a copolymer before nuclear hydrogenation is 70,000 to 200,000, preferably 70,000 to 180,000, and more preferably 70,000 to 150,000. When the weight average molecular weight of the block copolymer (II) is less than 70,000, the resulting hydrogenated aromatic vinyl copolymer composition has low impact resistance. On the other hand, if the weight average molecular weight of the block copolymer (II) is more than 200,000, the fluidity of the resulting hydrogenated aromatic vinyl copolymer composition is lowered, and handling becomes difficult.

  Further, the block copolymer (II) which is a copolymer before nuclear hydrogenation is 80% or more of the double bond derived from the second conjugated diene monomer, preferably 85% or more, more preferably 90% or more, Particularly preferably, 95% or more is hydrogenated. That is, the hydrogenation rate of the block copolymer (II) is 80% or more (excluding nuclear hydrogenation). By making the hydrogenation rate of the block copolymer (II) 80% or more, problems such as gelation reaction caused when hydrogenating the block copolymer composition containing the block copolymer (II) are eliminated. Occurrence can be avoided.

  The block copolymer (II) is synthesized by a conventionally known method disclosed in, for example, JP-A-2-133406, JP-A-3-128957, and JP-A-5-170844. be able to.

(3) Block copolymer composition (copolymer composition before hydrogenation)
The block copolymer composition, which is a pre-hydrogenation copolymer composition of the hydrogenated aromatic vinyl copolymer composition of the present embodiment, comprises the above-mentioned block copolymer (I) and block copolymer (II). ) With a mass ratio of (I) / (II) = 95/5 to 80/20, preferably (I) / (II) = 95/5 to 85/15, more preferably (I) / (II) = 93/7 to 88/12 in a mass ratio. When the content ratio of the block copolymer (I) is less than 80% by mass, the total light transmittance of the hydrogenated aromatic vinyl copolymer composition obtained by using this block copolymer is decreased, and It becomes difficult to ensure sufficient transparency as a component material. On the other hand, when the content ratio of the block copolymer (I) is more than 95% by mass, the resulting hydrogenated aromatic vinyl copolymer composition has low impact resistance.

(4) Aromatic vinyl monomer Block copolymers (I) and (B) contained in the block copolymer composition which is a pre-hydrogenated copolymer of the hydrogenated aromatic vinyl copolymer composition of the present embodiment. Examples of the first and second aromatic vinyl monomers constituting II) include styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-isopropylstyrene, α-t-butylstyrene, Examples include 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-t-butylstyrene, and 5-t-butyl-2-methylstyrene. be able to. Among these, styrene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α can be used industrially and to obtain a hydrogenated aromatic vinyl copolymer composition having excellent physical properties. -Isopropyl styrene, α-t-butyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene, 2,4-dimethyl styrene, 2,4-diisopropyl styrene are preferable, styrene, α-methyl styrene, α -Ethyl styrene, α-propyl styrene, α-isopropyl styrene, α-t-butyl styrene, 2-methyl styrene, 3-methyl styrene, 4-methyl styrene are more preferable. In addition, an aromatic vinyl monomer may be used independently or may use 2 or more types together.

  Further, the aromatic vinyl block constituting the block copolymers (I) and (II) does not necessarily need to be composed only of an aromatic vinyl monomer. Therefore, the aromatic vinyl block may comprise, for example, a conjugated diene monomer in part.

(5) Conjugated diene monomer The block copolymers (I) and (II) contained in the block copolymer composition which is a pre-hydrogenated copolymer of the hydrogenated aromatic vinyl copolymer composition of the present embodiment. As the first and second conjugated diene monomers constituting each of the above), for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1 , 3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, and the like. Among these, 1,3-butadiene, isoprene, and 1,3-pentadiene are preferable for obtaining a hydrogenated aromatic vinyl copolymer composition that can be industrially used and has excellent physical properties. 3-butadiene and isoprene are more preferable. In addition, a conjugated diene monomer may be used independently or may use 2 or more types together.

(6) Hydrogenation rate The hydrogenated aromatic vinyl copolymer composition of the present embodiment includes an aromatic ring derived from the first and second aromatic vinyl monomers of the block copolymer composition, and 97% or more, preferably 98% or more, more preferably 99% or more of the double bonds derived from the first and second conjugated diene monomers are hydrogenated. That is, the hydrogenation rate of the hydrogenated aromatic vinyl copolymer composition of the present embodiment is 97% or more including nuclear hydrogenation. When the hydrogenation rate is less than 97%, the total light transmittance decreases, and it becomes difficult to ensure sufficient transparency as a material for optical components.

  Examples of the hydrogenation catalyst used for hydrogenation include solid or liquid catalysts. Specific examples of the solid catalyst include fine powders of noble metals such as ruthenium, rhodium, palladium, platinum and nickel, or catalysts in which these noble metals are supported on a support such as activated carbon, silica and alumina. Specific examples of the liquid catalyst include a catalyst obtained by reducing a complex obtained by solubilizing a transition metal element such as chromium or cobalt in an organic solvent with an alkyl metal compound.

  The hydrogenated aromatic vinyl copolymer composition of the present embodiment is obtained by hydrogenating a block copolymer composition by a hydrogenation step under predetermined conditions. This hydrogenation step is preferably carried out under conditions of a reaction temperature of 130 to 250 ° C., a hydrogen pressure of 5 to 15 MPa, and a reaction time of 1 to 24 hours, a reaction temperature of 200 to 240 ° C., a hydrogen pressure of 10 to 14 MPa, More preferably, the reaction is carried out under conditions of a reaction time of 3 to 10 hours.

  The solvent used in the production of the hydrogenated aromatic vinyl copolymer composition of the present embodiment is one that can dissolve the obtained hydrogenated aromatic vinyl copolymer composition and does not become a catalyst poison. That's fine. Specific examples of the solvent include cycloalkanes such as cyclohexane, methylcyclohexane and dimethylcyclohexane, and alkanes such as n-hexane. In order to adjust the hydrogenation conditions, a small amount of a polar compound such as alcohol, ether or ketone can be added to the solvent.

  It is preferable to remove the hydrogenation catalyst from the reaction solution after completion of the hydrogenation. When the hydrogenation catalyst is solid, it can be removed by a filtration method or the like. On the other hand, when the hydrogenation catalyst is liquid, it can be removed by a method of washing with water after adding a chelating agent or the like. The hydrogenated aromatic vinyl copolymer composition of this embodiment can be obtained by removing the solvent from the reaction solution from which the hydrogenation catalyst has been removed by a method such as stripping or reprecipitation and drying. .

  The hydrogenated aromatic vinyl copolymer composition of the present embodiment preferably has a glass transition point (Tg) of 120 ° C. or higher, more preferably 123 ° C. or higher, and 124 ° C. or higher. Particularly preferred. When the glass transition point (Tg) is less than 120 ° C., the heat resistance tends to be inferior. As used herein, “glass transition point (Tg) (° C.)” refers to a value measured and calculated by DSC.

  The hydrogenated aromatic vinyl copolymer composition of the present embodiment preferably has a weight average molecular weight of 50,000 or more, more preferably 550,000 or more, and 60,000 or more. Is particularly preferred. When the weight average molecular weight is less than 50,000, the impact resistance tends to be inferior. As used herein, “weight average molecular weight (Mw)” refers to a value calculated in terms of polystyrene using gel permeation chromatography (GPC).

  The hydrogenated aromatic vinyl copolymer composition of the present embodiment preferably has a light transmittance of 750 nm wavelength light at a thickness of 25 mm of 88% or more, more preferably 90% or more, 91 % Or more is particularly preferable. When the light transmittance at 750 nm is less than 88%, transparency as a resin material for constituting an optical component tends to be insufficient. In the present specification, “light transmittance (%)” means a temperature condition of 25 ° C. for a molded sheet having a thickness of 25 mm produced using a hydrogenated aromatic vinyl copolymer composition to be measured. Below, it refers to the value measured with 750 nm wavelength light.

  The hydrogenated aromatic vinyl copolymer composition of the present embodiment may contain other components as long as the excellent properties such as transparency, impact resistance, and low water absorption are not impaired. . Other components include, for example, anti-aging agents, weathering agents, metal deactivators, light stabilizers, UV absorbers, heat stabilizers and other stabilizers, antibacterial / antifungal agents, dispersants, plasticizers, crosslinks Agents, co-crosslinking agents, vulcanizing agents, vulcanization aids, foaming agents, foaming aids and the like.

2. Molded Article One embodiment of the molded article of the present invention is formed by molding any of the hydrogenated aromatic vinyl copolymer compositions described above. That is, the molded article of the present embodiment is a hydrogenated aromatic vinyl having various properties such as excellent transparency and impact resistance, low water absorption, and low birefringence as described above. It is formed by molding a copolymer composition. Therefore, the molded product of the present embodiment is excellent as transparency and impact resistance, has low water absorption, and has a low birefringence, and thus is suitable as an optical component.

  Specific examples of the molded product of this embodiment include an optical lens and a transparent film. More specifically, examples include a lens for a mobile phone with a camera, a pickup lens, a polycon mirror for a laser printer, and an optical disk substrate.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. In the examples and comparative examples, “parts” and “%” are based on mass unless otherwise specified. Moreover, the measuring method and evaluation method of various physical property values are shown below.

  [Styrene content]: Measured and calculated by infrared absorption spectroscopy.

  [Vinyl bond (1,2-bond) content]: Calculated by the Hampton method using an infrared absorption spectrum method.

[Weight average molecular weight (Mw)]: Calculated in terms of polystyrene using gel permeation chromatography (GPC, column: trade name “GMH _HR- H” (manufactured by Tosoh Corporation)).

[Hydrogenation rate]: Measured and calculated by 500 MHz, ¹ H-NMR spectrum.

  [Glass transition point (Tg)]: Measured and calculated by DSC (trade name “DSC2920” (manufactured by TI Instruments)).

  [Light transmittance]: Using a visible ultraviolet spectrophotometer (trade name “haze-guard plus” (manufactured by BYK-Gardner Gmbh)), a molded sheet having a thickness of 25 mm is subjected to a temperature condition of 750 nm at a temperature of 25 ° C. The wavelength light was measured.

  [Water Absorption Rate]: Based on JIS K 7105 (Measurement Method A), a 25 mm-thick molded sheet cut into a square (10 mm × 10 mm) was immersed in distilled water for 24 hours for measurement and calculation.

  [Izod impact strength]: Measured on a test piece with a notch according to ASTM D256.

[Photoelastic coefficient (× 10 ⁻¹² Pa ⁻¹ )]: A molded sheet having a thickness of 2.5 mm, which was vacuum-dried at 100 ° C. for 20 hours, was 5 ° C. above the glass transition point (Tg) of the material constituting the sheet. The film was stretched with a tensile tester at a high temperature, and the stress (Pa) and the refractive index were measured. The refractive index was measured at a measurement wavelength of 589.3 nm using a refractive index measuring device (trade name “KOBRA-21 ADH” (manufactured by Oji Scientific Instruments)). The refractive index difference Δn is plotted on the vertical axis, and the stress (Pa) is plotted on the horizontal axis, and the slope is taken as the photoelastic coefficient (× 10 ⁻¹² Pa ⁻¹ ).

(Synthesis Example 1)
25 kg of cyclohexane, 1 g of tetrahydrofuran, 2300 g of styrene, and 7.8 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 400 g of 1,3-butadiene was added to perform further adiabatic polymerization. After 30 minutes, 2300 g of styrene was added again to perform further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to normal temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water and the solvent was removed by steam distillation to obtain a block copolymer A. The resulting block copolymer A had a styrene content of 92%, a vinyl bond content of 15%, a weight average molecular weight (Mw) of 91,000, and a hydrogenation rate of 99%.

(Synthesis Example 2)
25 kg of cyclohexane, 1.5 g of tetrahydrofuran, 2500 g of styrene, and 7.8 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 500 g of 1,3-butadiene was added to perform further adiabatic polymerization. After 30 minutes, 2000 g of styrene was added again to conduct further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to normal temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water and the solvent was removed by steam distillation to obtain a block copolymer B. Table 1 shows the styrene content, vinyl bond content, weight average molecular weight (Mw), and hydrogenation rate of the obtained block copolymer B.

(Synthesis Example 3)
25 kg of cyclohexane, 1 g of tetrahydrofuran, 1400 g of styrene, and 7.8 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 2,300 g of 1,3-butadiene was added to conduct further adiabatic polymerization. After 30 minutes, 1300 g of styrene was added again to perform further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to normal temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain block copolymer C. Table 1 shows the styrene content, vinyl bond content, weight average molecular weight (Mw), and hydrogenation rate of the obtained block copolymer C.

(Synthesis Example 4)
25 kg of cyclohexane, 1.8 g of tetrahydrofuran, 1200 g of styrene and 7.8 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 2,600 g of 1,3-butadiene was added to perform further adiabatic polymerization. After 30 minutes, 1200 g of styrene was added again to perform further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to room temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a block copolymer D. Table 1 shows the styrene content, vinyl bond content, weight average molecular weight (Mw), and hydrogenation rate of the obtained block copolymer D.

(Synthesis Example 5)
25 kg of cyclohexane, 1 g of tetrahydrofuran, 1100 g of styrene, and 7.2 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 2,800 g of 1,3-butadiene was added to perform further adiabatic polymerization. After 30 minutes, 1100 g of styrene was added again to perform further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to normal temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water, and the solvent was removed by steam distillation to obtain a block copolymer E. Table 1 shows the styrene content, vinyl bond content, weight average molecular weight (Mw), and hydrogenation rate of the obtained block copolymer E.

(Synthesis Example 6)
25 kg of cyclohexane, 1 g of tetrahydrofuran, 900 g of styrene, and 7.8 g of n-butyllithium were placed in a reaction vessel having an internal volume of 50 liters purged with nitrogen, and adiabatic polymerization was performed from 70 ° C. After completion of the polymerization reaction, 3200 g of 1,3-butadiene was added to perform further adiabatic polymerization. After 30 minutes, 900 g of styrene was added again to conduct further adiabatic polymerization. After the completion of the polymerization reaction, the mixture was stirred for 20 minutes while supplying hydrogen gas at a pressure of 0.4 MPa-G to react with the polymer terminal lithium living as a living anion to obtain lithium hydride. A hydrogenation catalyst mainly composed of a titanocene compound was added at a temperature of the reaction solution of 90 ° C., and a hydrogenation reaction was carried out at a hydrogen pressure of 0.8 MPa for 2 hours. When the absorption of hydrogen was completed, the reaction system was returned to normal temperature and normal pressure, and the reaction solution was extracted from the reaction vessel. The extracted reaction solution was stirred into water and the solvent was removed by steam distillation to obtain a block copolymer F. Table 1 shows the styrene content, vinyl bond content, weight average molecular weight (Mw), and hydrogenation rate of the obtained block copolymer F.

Example 1
In a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 450 g of block copolymer A, and 50 g of block copolymer E are placed, and stirred at room temperature for 8 hours to block copolymers A and E. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was subjected to pressure filtration with a 1 μm Millipore filter, solidified with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer composition (Example 1). ) The hydrogenated aromatic vinyl copolymer composition (Example 1) obtained had a hydrogenation rate of 98.5%, a weight average molecular weight (Mw) of 61,000, and a glass transition point (Tg) of 123. The light transmittance was 91%, the water absorption was 0.02%, the Izod impact strength was 45 J / m, and the photoelastic coefficient was −150 × 10 ⁻¹² Pa ⁻¹ at 5 ° C.

(Example 2)
In a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 475 g of block copolymer B, and 75 g of block copolymer D are put, and stirred at room temperature for 8 hours to block copolymers B and D. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was filtered under pressure with a 1 μm Millipore filter, solidified with methanol, and then vacuum-dried to obtain a hydrogenated aromatic vinyl copolymer composition (Example 2). ) Table 2 shows various physical property values of the obtained hydrogenated aromatic vinyl copolymer composition (Example 2). Moreover, the infrared absorption spectrum and ¹ H-NMR chart of the hydrogenated aromatic vinyl copolymer (Example 2) are shown in FIGS. 1 and 2, respectively.

(Example 3)
In a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 475 g of block copolymer B, and 25 g of block copolymer D are put, and stirred at room temperature for 8 hours to block copolymers B and D. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was subjected to pressure filtration with a 1 μm Millipore filter, solidified with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer composition (Example 3). ) Table 2 shows various physical property values of the resulting hydrogenated aromatic vinyl copolymer composition (Example 3).

(Comparative Example 1)
2000 g of cyclohexane and 500 g of block copolymer A were placed in a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, and the block copolymer A was dissolved by stirring at room temperature for 8 hours. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high pressure reaction vessel to room temperature, the reaction solution is pressure filtered through a 1 μm Millipore filter, coagulated with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer (Comparative Example 1). Obtained. Table 2 shows various physical property values of the obtained hydrogenated aromatic vinyl copolymer (Comparative Example 1).

(Comparative Example 2)
In a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 375 g of block copolymer A, and 125 g of block copolymer E are placed, and stirred at room temperature for 8 hours to block copolymers A and E. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was subjected to pressure filtration with a 1 μm Millipore filter, solidified with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer composition (Comparative Example 2). ) Table 2 shows various physical property values of the obtained hydrogenated aromatic vinyl copolymer composition (Comparative Example 2).

(Comparative Example 3)
In a high pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 450 g of block copolymer A, and 50 g of block copolymer C are placed, and stirred for 8 hours at room temperature to block copolymers A and C. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N163” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was subjected to pressure filtration with a 1 μm Millipore filter, solidified with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer composition (Comparative Example 3). ) Table 2 shows various physical property values of the obtained hydrogenated aromatic vinyl copolymer composition (Comparative Example 3).

(Comparative Example 4)
In a high-pressure reaction vessel with an internal volume of 5 liters purged with nitrogen, 2000 g of cyclohexane, 450 g of block copolymer B, and 50 g of block copolymer F are placed, and stirred at room temperature for 8 hours to block copolymers B and F. Was dissolved. In this high-pressure reaction vessel, 25 g of a supported Ni catalyst (trade name “N103” (manufactured by JGC Chemical Co., Ltd.)) was added, and the system was purged with nitrogen. After adjusting the hydrogen pressure to 1 MPa, when the temperature was raised to 230 ° C. while stirring, the hydrogen pressure was increased to 10 MPa and stirred for 5 hours while maintaining the hydrogen pressure. After cooling the high-pressure reaction vessel to room temperature, the reaction solution was subjected to pressure filtration with a 1 μm Millipore filter, solidified with methanol, and then vacuum dried to obtain a hydrogenated aromatic vinyl copolymer composition (Comparative Example 4). ) Table 2 shows various physical property values of the obtained hydrogenated aromatic vinyl copolymer composition (Comparative Example 4).

  As shown in Table 2, the molded sheets comprising the hydrogenated aromatic vinyl copolymer compositions of Examples 1 to 3 all have a light transmittance of 90% or more at 25 ° C. and 750 nm, and are transparent. It is clear that it is excellent. In addition, the molded sheets made of the hydrogenated aromatic vinyl copolymer compositions of Examples 1 to 3 all have a water absorption value of 0.05% or less, which is sufficiently low. . Further, the molded sheet made of the hydrogenated aromatic vinyl copolymer composition of Examples 1 to 3 has higher Izod impact strength than the molded sheet made of the hydrogenated aromatic vinyl copolymer of Comparative Example 1. It can be seen that it has excellent impact resistance. The molded sheets made of the hydrogenated aromatic vinyl copolymer compositions of Comparative Examples 2 to 4 have high Izod impact strength but low light transmittance and glass transition point (Tg).

In addition, the molded sheets made of the hydrogenated aromatic vinyl copolymer compositions of Examples 1 to 3 have a photoelastic coefficient (× 10 ⁻¹² Pa ⁻¹ ) absolute value in the range of 300 and birefringence. Is small and has little optical anisotropy.

  The hydrogenated aromatic vinyl copolymer composition of the present invention is a resin material having excellent transparency and impact resistance, low water absorption, and low birefringence. Therefore, it is suitable as a constituent material for optical lenses and transparent films. More specifically, it is suitable as a constituent material for lenses for camera-equipped mobile phones, pickup lenses, polycon mirrors for laser printers, optical disk substrates, and the like.

2 is an infrared absorption spectrum of the hydrogenated aromatic vinyl copolymer composition of Example 2. 2 is a ¹ H-NMR chart of a hydrogenated aromatic vinyl copolymer composition of Example 2. FIG.

Claims (3)

Hydrogenated aromatic vinyl copolymer composition obtained by hydrogenating a block copolymer composition containing an aromatic vinyl monomer and two or more block copolymers comprising monomer structural units containing a conjugated diene monomer Because
The block copolymer composition is composed of a monomer constituent unit containing a first aromatic vinyl monomer and a first conjugated diene monomer, and a block copolymer (I) satisfying the following condition (1):
A block copolymer (II) consisting of a monomer constituent unit containing a second aromatic vinyl monomer and a second conjugated diene monomer and satisfying the following condition (2): (I) / (II) = 95 / Containing at a mass ratio of 5-80 / 20,
Hydrogenated aromatic vinyl in which 97% or more of the aromatic rings derived from the first and second aromatic vinyl monomers and the double bond derived from the first and second conjugated diene monomers are hydrogenated. -Based copolymer composition.
Condition (1): The content ratio of the structural unit derived from the first aromatic vinyl monomer is 90 to 95% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the first conjugated diene monomer are hydrogenated.
Condition (2): The content ratio of the structural unit derived from the second aromatic vinyl monomer is 40 to 60% by mass, the weight average molecular weight is 70,000 to 200,000, the block structure is represented by the following general formula (1), More than 80% of the double bonds derived from the second conjugated diene monomer are hydrogenated.
A-B-A (1)
(In the general formula (1), A is a structural unit derived from the first or second aromatic vinyl monomer, and B is a structural unit derived from the first or second conjugated diene monomer)   2. The hydrogenated aromatic vinyl copolymer composition according to claim 1, wherein the glass transition point is 120 ° C. or more, the weight average molecular weight is 50,000 or more, and the light transmittance of 750 nm wavelength light at a thickness of 25 mm is 88% or more. object.   A molded article formed by molding the hydrogenated aromatic vinyl copolymer composition according to claim 1.

Images