JP2002060447A - Hydrogenated block copolymer of styrene based aromatic hydrocarbon and conjugate diene, its composition, and optical molding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a copolymer of a styrene based aromatic hydrocarbon and a conjugate diene in which moldability is compatible with the mechanical property of a molding. SOLUTION: The copolymer is obtained by the hydrogenation of unsaturated groups in a block copolymer of the styrene based aromatic hydrocarbon and the conjugate diene. In the copolymer, the chain ends are hydrogenated conjugate diene polymer blocks, the weight ratio of hydrogenated styrene based aromatic hydrocarbon polymer block/hydrogenated conjugate diene polymer block is 70/30-99/1, the hydrogenated rate of unsaturated groups in the copolymer is not less than 90 mol%, and the hydrogenated conjugate diene polymer block is amorphous. A composition containing the copolymar and the use of the composition are also provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer and a composition containing the same, as well as an injection molding resin and an optical molding material comprising the same. More specifically, hydrogenation in which a hydrogenated conjugated diene polymer block is contained at the terminal of a molecular chain, which is excellent in moldability, transparency, optical isotropy, heat resistance, dimensional stability (low water absorption) and mechanical properties. Provided are a styrene-based aromatic hydrocarbon-conjugated diene block copolymer and a composition, and an injection molding resin and an optical molding material comprising the same.

[0002]

2. Description of the Related Art In addition to transparency, plastics used for optical molding materials such as optical disk substrates, optical lenses, and liquid crystal display substrates include optical isotropy (low birefringence), dimensional stability, and the like. Various characteristics such as light resistance, weather resistance, and thermal stability are required. Conventionally, polycarbonate or polymethyl methacrylate has been mainly used as these transparent plastics.However, polycarbonate has a large intrinsic birefringence and tends to cause optical anisotropy in molded products. Due to the extremely high water absorption, poor dimensional stability and low physical heat resistance have been problems.

At present, polycarbonate is exclusively used as an optical disk substrate. In recent years, polycarbonate is typified by an increase in capacity of a magneto-optical recording disk (MO), development of a digital video disk (DVD), and development of a blue laser. With the increase in recording density and the like, problems such as the degree of birefringence of polycarbonate and the warpage of disks due to moisture absorption have been raised.

[0004] Under these circumstances, amorphous polyolefin-based resins have been actively developed in recent years as alternative materials to polycarbonate. As an example of these, hydrogenated polystyrene obtained by hydrogenating an aromatic group of polystyrene to form a polyvinylcyclohexane structure (Japanese Patent Publication No. 7-114030)
Has been proposed. Further, application to optical molding materials such as optical discs using this resin has also been proposed.

[0005] This resin has a great advantage that it can be produced at a lower cost than other amorphous polyolefins.
It has major drawbacks in that it lacks thermochemical stability and is mechanically brittle. Generally, an optical disk substrate made of such a resin is formed by an injection molding method or an injection / compression molding method. In order to ensure transferability corresponding to a fine recording pattern, the fluidity of the resin must be increased, and vigorous high-temperature molding is required. This request
It is becoming more and more severe as recording density increases.

However, due to lack of thermal stability,
There is a limit to the molding temperature. On the other hand, in order to obtain high fluidity even at a low temperature, a method of lowering the molecular weight may be used. However, if the molecular weight is reduced, a decrease in mechanical properties of the obtained molded product cannot be avoided. Further, in order to avoid a decrease in mechanical properties, a styrene-based monomer is obtained by block-copolymerizing a conjugated diene-based monomer with a styrene-based diene-styrene block copolymer. Styrene-based copolymers have been proposed (see, for example,
0-116442, JP-A-1-294721 and JP-A-1
318180, WO99 / 64479, etc.).

[0007] Such a block copolymer has a so-called sea-island structure in which islands composed of flexible hydrogenated diene polymer blocks float in the sea composed of rigid hydrogenated styrene polymer blocks. For this reason, the mechanical strength can be improved to some extent by absorbing the impact by the islands composed of the flexible chains. However, even with such a block copolymer, it is difficult to achieve both fluidity and mechanical properties sufficient to satisfy the transferability of a high-definition recording pattern. In view of such a situation, development of a novel hydrogenated styrene-based aromatic hydrocarbon polymer including novel hydrogenated polystyrene, which has both moldability and mechanical properties, is awaited.

[0008]

As is apparent from the above-mentioned prior art, an object of the present invention is to provide a hydrogenated styrene-based aromatic hydrocarbon having both moldability and mechanical properties of a molded article.
It is to provide a conjugated diene copolymer.

Another object of the present invention is to provide a hydrogenated styrene-based aromatic hydrocarbon-conjugated diene copolymer excellent in melt fluidity and moldability, and excellent in transparency, mechanical properties and physical heat resistance of a molded article. It is to provide coalescence.

It is still another object of the present invention to provide an injection molding resin and an optical molding material such as an optical disk substrate material mainly composed of the above hydrogenated styrene-based aromatic hydrocarbon-conjugated diene copolymer. It is in.

[0011]

In order to simultaneously solve the above-mentioned incompatibility in hydrogenated styrenic aromatic hydrocarbon polymers, the present inventors have proposed a hydrogenated conjugated polymer which is considered to be a flexible chain. We focused on maximizing the entanglement between the molecular chains of the diene polymer block and improving the mechanical properties based on the entanglement.

Generally, a polymer chain composed of a rigid straight chain is hardly entangled. On the other hand, a polymer chain composed of a flexible chain is easily entangled. L. J. Fetters et al.
moleculars, Volume 27, Num
ber 17, Page 4639 (1994), whereas the molecular weight between the entanglement points of the polyethylene (corresponding to the hydrogenated butadiene polymer) chain is 828,
It is reported that the molecular weight between the entanglement points of the polyvinylcyclohexane (corresponding to the hydrogenated styrene polymer) chain is 38,966. Therefore, entanglement at the part of the hydrogenated styrene polymer chain cannot be expected so much. For example, even with a hydrogenated styrene polymer having a molecular weight of 200,000, only about 5 entanglement points occur on average. By introducing a hydrogenated conjugated diene polymer chain, compared to only a hydrogenated styrene-based aromatic hydrocarbon polymer chain,
Improvement of mechanical properties based on high entanglement can be expected.

However, in the conventionally proposed block copolymers of the hydrogenated styrene-conjugated diene-styrene type, the flexible and relatively short hydrogenated conjugated diene polymer block is replaced by a rigid and long hydrogenated styrene polymer block. The flexibility of the flexible chain decreases,
Unless the flexible chain is lengthened, sufficient entanglement cannot be obtained.
But then, the glass transition point of the polymer goes down,
It cannot be put to practical use.

On the other hand, for example, hydrogenated conjugated diene
When a relatively short and flexible hydrogenated conjugated diene polymer block is disposed at both ends of a long and rigid hydrogenated styrene polymer block such as a styrene-conjugated diene type block copolymer, a flexible hydrogenated conjugated diene can be obtained. The polymer block, even if shorter, has more freedom for entanglement. Moreover,
However, if the block extends over two islands, a unique structure in which rigid hydrogenated styrene polymer blocks are arranged in a three-dimensional network is expected. On the other hand, such effects cannot be expected at all with the conventionally proposed hydrogenated styrene-conjugated diene-styrene type block copolymer. Even with such a block arrangement, it is expected that the melt viscosity based on entanglement is not much different from that of a conventional block copolymer due to high entropy at the time of melting.

Further, a small amount of a hydrogenated styrene-based aromatic hydrocarbon polymer having a very high molecular weight similar structure to the amorphous hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is used. When blended, the similar polymer does not impair the fluidity of the blend composition in the molten state, and in the solid state, the similar polymer chains sew the network structure of the hydrogenated styrene-based aromatic hydrocarbon polymer. Entangled, so-called interpenetrating network structure (Interpenet
(Rating network or IPN) can be expected. Therefore, entanglement is strengthened, and improvement in mechanical properties can be expected.

The present inventors have made intensive studies based on the above-described molecular design concept, and as a result, completed the present invention. That is, the present invention relates to a copolymer obtained by hydrogenating an unsaturated group of a block copolymer of a styrene-based aromatic hydrocarbon and a conjugated diene, and (A) a chain end of which is a hydrogenated conjugated diene polymer. Weight ratio of (ii) hydrogenated styrene-based aromatic hydrocarbon polymer block to hydrogenated conjugated diene polymer block (hydrogenated styrene-based aromatic hydrocarbon polymer block / hydrogenated conjugated diene polymer block) )
Is 70/30 to 99/1, (c) the hydrogenation rate of the unsaturated group present in the copolymer is 90 mol% or more, and (d) the hydrogenated diene polymer block is amorphous. Is a hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer.

In the present invention, in addition to the above-mentioned invention (hereinafter referred to as the above-mentioned invention), The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to the above-mentioned invention, wherein the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is linear. 3. 3. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to the above-mentioned invention or 2, wherein the conjugated diene is butadiene or isoprene. 4. Number average molecular weight of 30,000 to 500,000
4. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above-mentioned inventions and 2 to 3.

5. 5. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above inventions, wherein the molecular weight of the hydrogenated conjugated diene polymer block at the chain end is 3,000 or more, and 6. 6. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above inventions having a glass transition point of 120 ° C. or higher, and any one of 2 to 5. 7. The hydrogenation obtained by hydrogenating 10 to 99% by weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer and the styrene-based aromatic hydrocarbon polymer according to any of the above inventions and 2 to 6. A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition mainly comprising 90 to 1% by weight of a styrene-based aromatic hydrocarbon polymer.

8. The hydrogenation obtained by hydrogenating 70 to 99% by weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer and the styrene-based aromatic hydrocarbon polymer according to any one of the above inventions and 2 to 6. A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer having a number average molecular weight of less than 200,000; A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition having a number-average molecular weight of the system-based aromatic hydrocarbon polymer of 200,000 or more.

9. An injection molding resin mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above inventions and 2 to 6. 10. 9. A resin for injection molding mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to 7 or 8. 11. An optical molding material mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above inventions and 2 to 6.

[12] An optical molding material mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to 7 or 8. 13. 7. An optical disk substrate mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of the above inventions and 2 to 6. 14． 9. An optical disk substrate mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to 7 or 8. including.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
In the present invention, the chain end of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer comprises a hydrogenated conjugated diene polymer block. However, it does not prevent the presence of another hydrogenated conjugated diene polymer block between the hydrogenated styrene-based aromatic hydrocarbon polymer blocks. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer used in the present invention may be linear, radial (radial), or comb-shaped. However, in view of forming a crosslinked structure after cooling, it is not necessary to take a radial structure or a comb-like structure having nodes, and a linear structure that is most easily manufactured is preferable.

The styrene aromatic hydrocarbon used in the present invention includes styrene, α-methylstyrene,
p-Methylstyrene, vinyl naphthalene and the like. Of these, styrene is most preferably used in terms of availability and polymer properties. These may be used alone or in combination of two or more.

On the other hand, conjugated dienes copolymerizable with styrene aromatic hydrocarbons include butadiene, isoprene,
2,3-dimethylbutadiene, 2,3-pentadiene,
Dienes such as 2,3-hexadiene are preferably used. Of these, butadiene and isoprene are inexpensive industrial raw materials and are particularly preferred. These may be used alone or in combination of two or more.

The weight ratio of the styrene-based aromatic hydrocarbon polymer block to the conjugated diene polymer block (hydrogenated styrene-based aromatic hydrocarbon polymer block / hydrogenated conjugated diene polymer block) used in the present invention is as follows: 70 /
The range of 30 to 99/1, preferably 80/20 to 97
/ 3, more preferably in the range of 85/15 to 95/5. When the amount of the hydrogenated styrene-based aromatic hydrocarbon component exceeds the upper limit of this range, the amount of the hydrogenated conjugated diene polymer block component is too small, so that the molecular chain length of the hydrogenated conjugated diene polymer block cannot be sufficiently obtained. However, the entanglement of the amorphous conjugated diene polymer block is also unsatisfactory, which is not preferable. Conversely, if the amount of the hydrogenated styrene-based aromatic hydrocarbon polymer block component is less than the lower limit of this range, the amount of the hydrogenated conjugated diene block polymer component will be too large.
For this reason, the ratio of the amorphous soft phase composed of the conjugated diene polymer block is too large, and the glass transition temperature is lowered, which is not preferable from the viewpoint of heat resistance.

In the present invention, the hydrogenation rate of the unsaturated group present in the copolymer is at least 90 mol%, preferably at least 95 mol%, and more preferably at least 99 mol%. If it is less than this, the amount of unsaturated bonds becomes too large, which is not preferable from the viewpoint of transparency. Here, the term "hydrogenation rate" refers to the total hydrogenation rate of the double bond and the aromatic ring in the copolymer in which the aromatic ring is replaced by a mole corresponding to the double bond. For example, in the case of a copolymer using styrene, the non-hydrogenated styrene site is calculated as 3 moles of double bond. Usually, the double bond derived from the conjugated diene moiety is much more easily hydrogenated than the aromatic ring, and is almost completely hydrogenated in the present invention. On the other hand, when the aromatic ring is not hydrogenated, most of the ring remains the aromatic ring, but there are cases where the hydrogen is partially hydrogenated to form a double bond.

The number average molecular weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer used in the present invention is a molecular weight in terms of polystyrene obtained by gel permeation chromatography, and is preferably 30,000 or more. 500,000, more preferably 5
It ranges from 000 to 300,000. If it exceeds this, the hydrogenation reaction of the styrene-based aromatic hydrocarbon-conjugated diene block copolymer becomes difficult, and the melt viscosity of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer becomes too high. It is not preferable because molding becomes difficult. If it is less than that, the hydrogenation reaction becomes easy and the melt viscosity also decreases, but the molecular weight of the terminal hydrogenated conjugated diene polymer block becomes too low and the entanglement of the hydrogenated conjugated diene polymer block becomes insufficient. This is not preferable because mechanical strength based on entanglement cannot be maintained. The reduced viscosity measured in a dilute solution is also an important measure for grasping the molecular weight. In the present invention, the concentration is 0.5 g.
/ DL reduced viscosity η measured at 30 ° C in toluene solution
When expressed in sp / c, the reduced viscosity is preferably 0.1 to 5 dL / g, more preferably 0.2 to 2 dL / g.
g.

The molecular weight of the hydrogenated conjugated diene polymer block at the chain end in the present invention is preferably 3,000 or more,
More preferably, it is 5,000 or more. Below that,
The effect of entanglement between the hydrogenated conjugated diene polymer blocks is lost, which is not preferable.

Both the hydrogenated styrene-based aromatic hydrocarbon block and the hydrogenated conjugated diene block of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer in the present invention are amorphous. The non-crystallinity can be easily determined by a differential scanning calorimetry (DSC method) or the like. That is, if it is amorphous, the crystal melting point is not observed in the differential thermal analysis by the DSC method, and only the glass transition point is observed.

The glass transition point in the hydrogenated aromatic hydrocarbon-conjugated diene block copolymer in the present invention is preferably 120 ° C. or higher, more preferably 130 ° C. If it is less than that, it is not preferable because the physical heat resistance is low. However, the glass transition point is defined by the maximum slope point indicated by the inflection point obtained by the DSC method.

The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer used in the present invention is prepared by synthesizing a styrene-based aromatic hydrocarbon-conjugated diene block copolymer by a conventionally known method, and thereafter, preparing the styrene-based aromatic hydrocarbon-conjugated diene block copolymer. Obtained by hydrogenating the copolymer. Hereinafter, the preferred synthesis method will be described in detail. (Styrene-based aromatic hydrocarbon-conjugated diene block copolymer) The styrene-based aromatic hydrocarbon-conjugated diene block copolymer is produced by a conventionally known method such as anionic polymerization, radical polymerization, cationic polymerization, and coordination polymerization. However, it is preferable to use an anionic polymerization method from the viewpoint that the structure can be easily controlled.

Examples of the initiator for the polymerization using the anionic polymerization technique include metals of Groups 1 and 2 of the periodic table and organometallic compounds thereof. In particular,
Lithium, sodium, potassium, rubidium, cesium, francium, magnesium, calcium, strontium, barium, radium, methyl lithium, ethyl lithium, n-propyl lithium, iso-propyl lithium, n-butyl lithium, iso-butyl lithium, sec- Butyl lithium, cyclopentadienyl lithium, phenyl lithium, cyclohexyl lithium, methyl sodium, ethyl sodium, n-propyl sodium, iso-propyl sodium, n-butyl sodium, cyclopentadienyl sodium, dimethylmagnesium, bis (cyclopentadiene Enyl) magnesium, dimethyl calcium, bis (cyclopentadienyl) calcium, and the like. Of these, organolithium compounds are preferred in terms of availability and operability, and n-butyllithium and sec-butyllithium are particularly preferred. These may be used alone,
Two or more types may be combined.

In such a synthesis method, the polymerization reaction is usually carried out
This is performed using a hydrocarbon solvent. Preferred examples of the hydrocarbon solvent include C4-12 aliphatic hydrocarbons such as butane, n-pentane, n-hexane and n-heptane; cyclobutane, cyclopentane, methylcyclopentane,
C4-12 alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, cycloheptane, cyclooctane, and decalin; C6-12 aromatic carbons such as benzene, toluene, xylene, mesitylene, ethylbenzene, diethylbenzene, cumene, tetralin, and naphthalene Hydrogen may be mentioned. Among such hydrocarbon solvents, alicyclic hydrocarbons such as cyclohexane and methylcyclohexane are preferred from the viewpoints of the solubility and reactivity of the polymer and the suitability as a subsequent hydrogenation reaction solvent.

In conducting anionic polymerization, the above initiator is further activated to increase the reaction rate, increase the molecular weight, prevent the deactivation of anions, and control the microstructure of the conjugated diene portion. Compounds may be added. The electron donating compound is a compound that can donate electrons to the metal of the initiator without impairing the function of the initiator, and is a compound containing an oxygen atom, a nitrogen atom, a sulfur atom, and a phosphorus atom.

Specifically, furan, tetrahydrofuran,
Diethyl ether, anisole, diphenyl ether,
Ethers such as methyl-t-butyl ether, dioxane, dioxolan, dimethoxyethane, diethoxyethane; trimethylamine, triethylamine, tributylamine, tetramethylmethylenediamine, tetramethylethylenediamine, tetraethylmethylenediamine, tetraethylethylenediamine, tetramethyl1,3- Tertiary amines such as propanediamine, tetramethylphenylenediamine and diazabicyclo [2,2,2] octane; thioethers such as dimethylsulfide, thiophene and tetrahydrothiophene, trimethylphosphine, triethylphosphine, tri-n-butylphosphine and tri-amine Phenylphosphine, dimethylphosphinomethane, dimethylphosphinoethane, dimethylphosphinopropane, diphenylphosphine Finometan, diphenylphosphino ethane, mention may be made of tertiary phosphines such as diphenylphosphinopropane.

These may be used alone or in combination of two or more. By using such an electron donating compound, the polymerization structure at the 1,4-position of the conjugated diene can be reduced and the polymerization structure at the 1,2-position can be increased. As a result, what is originally crystalline can be made amorphous, which is preferable.

The reaction conditions at the time of polymerization are not particularly limited because they differ depending on the polymerization method and the like, but they are usually carried out in the range of -20 to 200 ° C, preferably 0 to 150 ° C, more preferably 10 to 100 ° C. Will be The reaction time is usually 5 minutes to 20 hours, preferably 10 minutes.
Minutes to 15 hours, more preferably 30 minutes to 10 hours. In addition, since the active end may be very sensitive to water, oxygen, etc. during the polymerization reaction, the reaction is carried out under an inert atmosphere such as nitrogen or argon, and in an environment where reagents, solvents, and inert gases are sufficiently dehydrated. Is preferred.

Specific examples of the polymerization reaction include the following methods. First, a conjugated diene is polymerized, and when the conjugated diene is substantially depleted, a styrene-based aromatic hydrocarbon is block-copolymerized, and then a conjugated diene is block-copolymerized. By this method, a conjugated diene-styrene-based aromatic hydrocarbon-conjugated diene complete block copolymer can be obtained.

First, a conjugated diene and a styrene-based aromatic hydrocarbon are simultaneously added and copolymerized, and when both are depleted, block copolymerization of the conjugated diene is continued. In this case, since the conjugated diene is much easier to be incorporated than the styrene-based aromatic hydrocarbon, the conjugated diene unit is preferentially incorporated at the first copolymerization stage, and the styrene-based aromatic hydrocarbon unit is located near the growth terminal. A living block copolymer of a so-called inclined (taper) type is obtained. Subsequent block copolymerization of a conjugated diene results in a conjugated diene-styrene-based aromatic hydrocarbon-conjugated diene in which one end is a gradient block mainly composed of conjugated diene units and the other end is a conjugated diene polymer block. A block copolymer is obtained.

(Hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer) The hydrogenation reaction of the obtained styrene-based aromatic hydrocarbon-conjugated diene block copolymer is as follows:
The method is not particularly limited and can be performed by a known method.

The hydrogenation catalyst used in the hydrogenation is not particularly limited as long as it can hydrogenate the aromatic ring and the carbon-carbon double bond contained in the copolymer. Is a solid catalyst in which a noble metal such as nickel, palladium, platinum, cobalt, ruthenium, and rhodium or a compound such as an oxide, salt, or complex thereof is supported on a porous carrier such as carbon, alumina, silica, silica alumina, and diatomaceous earth. Can be. Among them, those in which nickel, palladium, platinum, and ruthenium are supported on alumina, silica, silica alumina, and diatomaceous earth have high reactivity and are preferably used. Such a hydrogenation catalyst is preferably used in the range of 0.5 to 40% by weight based on the copolymer, depending on its catalytic activity.

[0042] The hydrogenation reaction is usually carried out in the presence of a solvent. The hydrogenation reaction may be performed after the polymer after the polymerization reaction is once isolated, but it is possible to use the polymerization solution as it is or to further add a necessary solvent,
It is also preferable from an economic viewpoint. Such a solvent is preferably selected in consideration of the hydrogenation catalytic ability, the presence or absence of side reactions such as molecular chain scission, the solubility of the polymer before and after the hydrogenation reaction, and the like.

Specifically, C4-12 aliphatic hydrocarbons such as butane, n-pentane, n-hexane and n-heptane; cyclobutane, cyclopentane, methylcyclopentane, cyclohexane, methylcyclohexane, cycloheptane, cycloheptane C4-12 alicyclic hydrocarbons such as octane and decalin; and C4-12 ethers such as diethyl ether, tetrahydrofuran and methyl-t-butyl ether.

Of these, although depending on the type of catalyst, cyclohexane, methylcyclohexane, methyl-
t-Butyl ether is particularly preferred. In addition, polar solvents such as esters and alcohols are added to the above-mentioned solvents within a range not hindering the solubility of the polymer, for the purpose of increasing the activity of the reaction, or suppressing the molecular weight reduction due to molecular chain breakage due to hydrogenolysis. You may.

In the present invention, it is preferable to carry out the hydrogenation reaction in the above-mentioned solvent system at a styrene copolymer concentration of 3 to 50% by weight. If the concentration of the copolymer is less than 3% by weight, it is not preferable in terms of productivity and economy, and 50% by weight.
If it exceeds, the solution viscosity is too high, which is not preferable in terms of handling and reactivity.

The hydrogenation reaction conditions depend on the catalyst used, but are usually 3 to 25 MPa in hydrogen pressure and 70 to 250 in reaction temperature.
It is performed within the range of ° C. If the reaction temperature is too low, the reaction hardly proceeds, and if the reaction temperature is too high, the molecular weight is likely to be reduced by hydrogenolysis, which is not preferable. In order to prevent a decrease in molecular weight due to molecular chain breakage and to promote the reaction smoothly, hydrogen is applied at an appropriate temperature and hydrogen pressure appropriately determined according to the type and concentration of the catalyst used, the concentration of the copolymer solution, the molecular weight, and the like. It is preferable to carry out a chemical reaction.

After the completion of the hydrogenation reaction, the catalyst can be removed by a known post-treatment method such as centrifugation or filtration. In the present invention used for the optical molding material, it is necessary to reduce the residual catalyst metal components such as Ni, Al, and Si in the resin as much as possible, and the total amount of the residual metal catalyst is preferably 10 ppm or less, more preferably 1 ppm
Or less, more preferably 500 ppb or less. In particular, in the present invention, among the residual metal catalysts, it is preferable to use a hydrogenated styrene-based copolymer having a transition metal content of 10 ppm or less, more preferably 5 ppm or less.
From the polymer solution from which the hydrogenation catalyst has been removed, the target hydrogenated styrene-based copolymer can be obtained by a method such as evaporation of the solvent, stripping, or reprecipitation.

In the present invention, the obtained styrene-based hydrocarbon-conjugated diene block copolymer may be used as a composition with another polymer instead of the block copolymer alone, depending on the purpose. Such other polymers include hydrogenated styrene-based aromatic hydrocarbon polymers. The hydrogenated styrene-based aromatic hydrocarbon polymer is described in, for example, JP-A-63-4
No. 391, and a hydrogenated styrene-based aromatic hydrocarbon polymer described in JP-A No. 391, and a hydride of a styrene-based aromatic hydrocarbon and a conjugated diene block copolymer described in JP-A-10-116442, for example. From the latter, the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer in the present invention is excluded. The composition of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is 10 to 99% by weight, preferably 20 to 98% by weight, more preferably 30 to 95% by weight. 90 to 1% by weight of the hydrogen polymer, preferably 80 to
A range of 2% by weight, more preferably 70 to 5% by weight is used.

In another embodiment of the composition of the present invention, the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is 70 to 99% by weight, preferably 75 to 9% by weight.
8% by weight, more preferably 80 to 95% by weight, and 30 to 1% by weight, preferably 25 to 2% by weight, more preferably 20 to 5% by weight of the hydrogenated styrenic aromatic hydrocarbon polymer, And the number average molecular weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is less than 200,000, preferably less than 1800,000, and the number-average molecular weight of the hydrogenated styrene-based aromatic hydrocarbon polymer Is more than 200,000, preferably 250,
It is a hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition having a molecular weight of 000 or more, more preferably 300,000 or more. By using such a composition, it is possible to obtain a reciprocal network structure effect.

The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer of the present invention or the composition thereof may be added with Irganox 1010, 1076 (Ciba Geigy Co., Ltd.) in order to improve the thermochemical stability during melt molding. Made)
It is preferable to add a hindered phenol-based stabilizer, such as a phosphine-based stabilizer such as Irgafos 168 (manufactured by Ciba Geigy), or an addition-type stabilizer such as Sumilizer GM or Sumilizer GS. If necessary, release agents such as long-chain aliphatic alcohols and long-chain aliphatic esters, and other additives such as lubricants, plasticizers, ultraviolet absorbers, and antistatic agents can be added.

The optical molding material of the present invention can be molded by a known molding method such as injection molding, injection / compression molding, extrusion molding, and solution casting. In particular, it can be suitably used for the production of molded articles such as optical disk substrates by injection molding or injection / compression molding. In molding such an optical disc, the resin temperature is 250 to 380 ° C., preferably 270 to 380 ° C.
350 ° C., more preferably in the range of 280 ° C. to 340 ° C., and a mold temperature of 40 to 130 ° C., preferably 6 ° C.
A range of 0 to 120C, more preferably 70 to 110C is used.

[0052]

According to the present invention, there is provided a hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer having a hydrogenated conjugated diene polymer block at the chain end and a composition thereof. This copolymer and its composition are excellent in melt fluidity, excellent in transparency, mechanical properties, and physical heat resistance, so that they are preferably used as injection molding resins and optical molding materials such as optical disc substrate materials. I can do it.

[0053]

The present invention will be described below in detail with reference to examples. However, the present invention is not limited to these examples. Cyclohexane, methyl-tert-butyl ether (solvent), isoprene, and styrene were all purified by distillation and sufficiently dried. n-Butyllithium was purchased from Kanto Chemical Co., Ltd. from N-hexane at a concentration of 1.6 M and used as it was. Ni / silica-alumina catalyst (Ni loading 65%) was purchased from Aldrich,
Used as is.

The measurements of various physical properties performed in the examples were performed by the following methods. Glass transition temperature (Tg): TA Instrumenten
ts 2920 type DSC, temperature rise rate 10 ° C
/ Min. Reduced viscosity: 30 ° C. of 0.5 g / dL toluene solution
The reduced viscosity η _sp / c at was measured.

Number average molecular weight: Gel permeation chromatography (GPC, Show, manufactured by Showa Denko KK)
x System-11) using tetrahydrofuran as a solvent to determine the molecular weight in terms of polystyrene. Hydrogenation rate: Quantified by ¹ H-NMR measurement using a JEOL JNR-EX270 type nuclear magnetic resonance absorption apparatus. Melt viscosity: The melt viscosity was measured at a shear rate of 10 ² s ^-1 and 10 ³ s ^-1 by using a height-type flow tester manufactured by Shimadzu Corporation.

Residual metal content in resin: Quantified by ICP emission spectrometry. Total light transmittance: An automatic digital haze meter UDH-20D manufactured by Nippon Denshoku Industries Co., Ltd. was used. Haze value: An automatic digital haze meter UDH-20D manufactured by Nippon Denshoku Industries Co., Ltd. was used. Izod impact strength: UF IMP manufactured by Kamishima Seisakusho
The molded samples were subjected to an impact test with and without notch using an ACT TESTER and measured.

[Example 1] The inside of a stainless steel autoclave having a capacity of 10 L was sufficiently dried and purged with nitrogen.
2,400 g of cyclohexane was charged. Further, an amount corresponding to 11.2 mmol of n-butyllithium was added at a concentration of 1.
The mixture was added in the form of a 6M hexane solution, and 30 g of isoprene was introduced to initiate polymerization. After stirring at a temperature of 50 ° C. for 2 hours to completely react isoprene, 480 g of styrene was added.
1900 g of cyclohexane was added, and the mixture was further reacted at 50 ° C. for 2 hours. Next, 28 g of isoprene was introduced and reacted at a temperature of 50 ° C. for 2 hours. After completion of the reaction, 2 mL of isopropanol was added to obtain an isoprene-styrene-isoprene triblock copolymer. The 0.
The reduced viscosity η _sp / c measured at 30 ° C. in a 5 g / dL toluene solution was 0.43 dL / g. ¹ H-NM
The weight ratio of styrene / isoprene determined by R is 89/11
Met.

To this terpolymer solution was added methyl-ter
700 g of t-butyl ether and 80 g of a Ni / silica-alumina catalyst (65% Ni loading) were added, and a hydrogen pressure of 1 g was added.
A hydrogenation reaction was performed at 0 MPa and a temperature of 180 ° C. for 4 hours.
After the temperature was returned to room temperature and the atmosphere was sufficiently replaced with nitrogen, the solution was taken out of the autoclave and subjected to pressure filtration using a membrane filter having a pore diameter of 0.1 micron to obtain a colorless and transparent solution. To this solution was added Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) as a stabilizer in an amount of 0.3 wt.
After the addition by weight, concentration under reduced pressure and flushing were performed, and the solvent was distilled off to obtain a massive colorless and transparent hydrogenated isoprene-styrene-isoprene terpolymer. When measured at 30 ° C. in a toluene solution having a concentration of 0.5 g / dL of the polymer, η _sp / c was 0.32 dL / g. The number average molecular weight determined by GPC was 100,000, and the molecular weight of the hydrogenated butadiene block was estimated to be 11,000 from the copolymer composition ratio.

When the hydrogenation rate was measured by ¹ H-NMR measurement, it was 99.9% or more. According to ICP emission spectroscopy, the amount of residual catalyst metal in the resin was 0.51 pp for Ni.
It was found that m and Al were 0.45 ppm and Si were 0.22 ppm, both of which were 1 ppm or less. Temperature 300
The melt viscosity measured in ° C is ¹ at a shear rate of 10 ² s ^-1 .
The fluidity was high at 460 ps at 000 ps and 10 ³ s ^-1 .

Next, injection molding was performed at a cylinder temperature of 300 ° C. and a mold temperature of 70 ° C. When a disk having a thickness of 2 mm obtained by the molding method was measured, the total light transmittance was 91%.
%, And the haze value was 0.8%, which was sufficiently high transparency as an optical molding material. The glass transition temperature measured by DSC was 142 ° C., and no crystal melting point was observed. When the impact resistance of the molded product was measured by an Izod impact test, it was 1.6 kgf · cm / cm.
² (with notch) and 8.0 kgf · cm · cm ² (without notch).

Example 2 The inside of a stainless steel autoclave having a capacity of 10 L was sufficiently dried and purged with nitrogen.
2,400 g of cyclohexane and 200 g of methyl-t-butyl ether were charged. Further, 50 g of butadiene was introduced, and subsequently an amount corresponding to 9 mmol of n-butyllithium was added in the form of a 1.6 M cyclohexane solution to initiate polymerization. After stirring at a temperature of 50 ° C. for 2 hours to completely react butadiene, 720 g of styrene and 1900 g of cyclohexane were added, and the mixture was further reacted at 50 ° C. for 2 hours. Next, 33 g of butadiene was introduced, and the temperature was increased to 5 ° C.
The reaction was performed at 0 degree for 2 hours. After completion of the reaction, 2 mL of isopropanol was added to obtain a butadiene-styrene-butadiene terpolymer. The reduced viscosity η _sp / c measured at 30 ° C. in a 0.5 g / dL toluene solution of this copolymer is as follows:
It was 0.62 dL / g. The weight ratio of styrene / butadiene determined by ¹ H-NMR was 90/10.

To 3500 g of this terpolymer solution, 700 g of methyl-tert-butyl ether and 80 g of Ni / silica-alumina catalyst (65% Ni loading) were added, and hydrogenation reaction was performed at a hydrogen pressure of 10 MPa and a temperature of 180 ° C. for 5 hours. Was done. After the temperature was returned to room temperature and the atmosphere was sufficiently replaced with nitrogen, the solution was taken out of the autoclave and subjected to pressure filtration using a membrane filter having a pore diameter of 0.1 micron to obtain a colorless and transparent solution. To this solution was added Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) as a stabilizer in an amount of 0.3% by weight based on the polymer, followed by concentration under reduced pressure and flushing. Butadiene-styrene-butadiene terpolymer was obtained.

When measured at 30 ° C. in a toluene solution having a concentration of 0.5 g / dL of such a polymer, η _sp / c was 0.1.
It was 52 dL / g. The number average molecular weight determined by GPC was 170,000, and the molecular weight of the hydrogenated butadiene block was estimated to be 17,000 from the copolymer composition ratio. ^{When the} hydrogenation rate was examined by ¹ H-NMR measurement, it was 9
It was 9.9% or more. According to ICP emission spectroscopic analysis, the amount of residual catalyst metal in the resin was 0.45 ppm for Ni,
It was found that Al was 0.29 ppm and Si was 0.28 ppm, both of which were 1 ppm or less. The melt viscosity measured at a temperature of 300 ° C. is 360 at a shear rate of 10 ² s ⁻¹ .
The fluidity was high at 1200 ps at 0 ps and 10 ³ s ^-1 . Glass transition temperature measured by DSC is 145
° C, and no crystalline melting point was observed.

Next, injection molding was performed at a cylinder temperature of 300 ° C. and a mold temperature of 80 ° C. When a disk having a thickness of 2 mm obtained by the molding method was measured, the total light transmittance was 91%.
%, And the haze value was 0.9%, which was sufficiently high transparency as an optical molding material. In addition, when the impact resistance of the molded product was measured by an Izod impact test, it was 1.7.
kgf · cm / cm ² (with notch), 8.0kgf ·
cm · cm ² (no notch).

Comparative Example 1 A nitrogen-substituted stainless steel autoclave was charged with 500 g of polystyrene having a number average molecular weight of 300,000, 3300 g of cyclohexane, and methyl-t.
-Butyl ether (700 g) and nickel / silica alumina (80 g) were added, and hydrogen pressure was set to 10 MPa and temperature was set to 180 ° C.
The hydrogenation reaction was performed for hours. The solution was taken out of the autoclave and subjected to pressure filtration using a membrane filter having a pore size of 0.1 μm, whereby a colorless and transparent solution was obtained.
To this solution was added 0.3% by weight of Sumilizer GS as a stabilizer relative to the polymer, and the mixture was concentrated under reduced pressure and flushed to distill off the solvent to obtain a massive colorless and transparent hydrogenated styrene polymer. ^The hydrogenation rate determined from ¹ H-NMR was 9
It was 9.9%. The glass transition temperature measured by DSC was 151 ° C. The melt viscosity measured at a temperature of 300 ° C. is 8000 ps at a shear rate of 10 ² s ⁻¹ and 10 ³
It was 2100 ps at s ⁻¹ and the fluidity was low.

Next, injection molding was performed at a cylinder temperature of 300 ° C. and a mold temperature of 70 ° C. When a disk having a thickness of 2 mm obtained by the molding method was measured, the total light transmittance was 91%.
%, And the haze value was 0.8%, which was sufficiently high transparency as an optical molding material. However, the impact resistance of the molded product measured by the Izod impact test was 1.3 kg.
f · cm / cm ² (with notch), 5.2kgf · cm
・ It was as low as cm ² (no notch).

Example 3 A hydrogenated isoprene-styrene-isoprene terpolymer solution obtained in the same manner as in Example 1 and a hydrogenated styrene polymer solution obtained in the same manner as in Comparative Example 1 were mixed. Mixing was performed so that the weight ratio of the coalesced was 80/20. To this solution, 0.3% by weight of Sumilizer GS as a stabilizer was added to the polymer, followed by concentration under reduced pressure and flushing to distill off the solvent to obtain a massive colorless and transparent polymer composition. The melt viscosity measured at a temperature of 300 ° C. is
2400 ps at 10 ² s ^-1 and 9 at 10 ³ s ^-1
20 ps, and the fluidity was high.

Next, injection molding was performed at a cylinder temperature of 300 ° C. and a mold temperature of 70 ° C. When a disk having a thickness of 2 mm obtained by the molding method was measured, the total light transmittance was 91%.
%, And the haze value was 1.0%, which was sufficiently high transparency as an optical molding material. In addition, when the impact resistance of the molded product was measured by an Izod impact test, it was 1.4.
kgf · cm / cm ² (with notch), 6.4kgf ·
cm · cm ² (no notch).

Continued on the front page (51) Int.Cl. ⁷ Identification FI FI Theme Court II (Reference) G02B 1/04 G02B 1/04 G11B 7/24 526 G11B 7/24 526N (72) Inventor Kaoru Iwata Sunrise in Iwakuni City, Yamaguchi Prefecture No.2-1, Teijin Co., Ltd. F-term in Iwakuni Research Center (reference) 4F071 AA12X AA22 AA22X AA75 AA81 AA86 AH14 BC02 BC03 4J002 BC02X BP01W GS02 4J026 HA05 HA06 HA14 HA15 HA16 HA26 HA32 HA39 HB05 HB06 HB14 HB16 HB14 HC49 HE02 4J100 AB00P AB02P AB03P AS01Q AS02Q AS03Q AS04Q CA04 CA31 DA01 DA25 HA03 HG01 JA36 5D029 KA13 KC04 KC07 KC10

Claims (14)

[Claims] 1. A copolymer obtained by hydrogenating an unsaturated group of a block copolymer of a styrenic aromatic hydrocarbon and a conjugated diene, wherein (a) a chain end of which is a hydrogenated conjugated diene polymer (B) weight ratio of hydrogenated styrene-based aromatic hydrocarbon polymer block to hydrogenated conjugated diene polymer block (hydrogenated styrene-based aromatic hydrocarbon polymer block / hydrogenated conjugated diene polymer block) ) Is 70/30 to 99/1, and (c) the hydrogenation rate of the unsaturated group present in the copolymer is 90/30.
(D) a hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer in which the hydrogenated conjugated diene polymer block is amorphous. 2. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to claim 1, wherein the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is linear. 3. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to claim 1, wherein the conjugated diene is butadiene or isoprene. 4. A number average molecular weight of 30,000 to 50.
The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 3, wherein the styrene-based aromatic hydrocarbon-conjugated diene block copolymer has a molecular weight of 000. 5. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to claim 1, wherein the molecular weight of the hydrogenated conjugated diene polymer block at the chain end is 3,000 or more. Coalescing. 6. The hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to claim 1, which has a glass transition point of 120 ° C. or higher. 7. A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 6 and hydrogenated styrene-based aromatic hydrocarbon polymer. A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition mainly comprising 90 to 1% by weight of the obtained hydrogenated styrene-based aromatic hydrocarbon polymer. 8. A hydrogenated styrene-based aromatic hydrocarbon polymer comprising 70 to 99% by weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 6. 30 to 1% by weight of the obtained hydrogenated styrene-based aromatic hydrocarbon polymer, and the number-average molecular weight of the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer is less than 200,000. A hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition wherein the number average molecular weight of the hydrogenated styrene-based aromatic hydrocarbon polymer is 200,000 or more. 9. An injection molding resin mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 6. 10. An injection molding resin mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to claim 7. 11. An optical molding material mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 6. 12. An optical molding material comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to claim 7 or 8. 13. An optical disk substrate mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer according to any one of claims 1 to 6. 14. An optical disk substrate mainly comprising the hydrogenated styrene-based aromatic hydrocarbon-conjugated diene block copolymer composition according to claim 7.