JP6534511B2 - Copolymer, method for producing the same, and sheet molded body - Google Patents

Description

  The present invention relates to a copolymer, a method for producing the same, and a sheet molded article.

  A copolymer using at least a cycloolefin as a monomer (hereinafter sometimes referred to as "cycloolefin copolymer") has a unit of an alicyclic structure, and therefore generally has excellent heat resistance. Moreover, since the unit derived from cycloolefin does not have an aromatic ring, it can contribute to the improvement of the transparency of the copolymer. From such an advantage, the cycloolefin copolymer is used in various materials, in particular, optical materials such as films and sheets. And as a cycloolefin type copolymer used for an optical material, what contains the unit derived from 1-alkene is known a lot.

  For example, Patent Document 1 has a weight-average molecular weight of 5,000 including a norbornene-based monomer and an ethylene-based monomer as a cycloolefin-based copolymer including a unit derived from 1-alkene. To 500,000 where n / n + m is 0, where n is the number of units derived from a norbornene monomer and m is the number of units derived from an ethylene monomer. Discloses a copolymer which is 3 to 0.995, and the copolymer has high heat resistance and high transparency, and is suitably used as a lens composition of a light emitting diode element for a liquid crystal display device. Disclose what can be done.

Unexamined-Japanese-Patent No. 2006-203213

  However, the conventional copolymer described above has a problem that toughness such as strain at break is not sufficient. And copolymers capable of exhibiting sufficient performance in terms of optical properties such as transparency, heat resistance, and toughness are not yet sufficiently developed, and further development is strongly demanded. It was

  An object of the present invention is to solve the above-mentioned problems in the prior art and to achieve the following objects. That is, it is an object of the present invention to provide a copolymer excellent in toughness while having high optical properties and heat resistance, and a method of producing such a copolymer.

  The inventors of the present invention conducted intensive studies to achieve the above object, and as a result, a co-olefin containing a unit derived from cycloolefin and a unit derived from 1-alkene in a predetermined ratio and having a specific structure The polymer was found to be excellent in toughness while having high optical properties and heat resistance, and the present invention was completed.

The present invention is based on the findings by the present inventors, and means for solving the problems are as follows. That is,
<1> A copolymer of a cycloolefin and a 1-alkene, which comprises more than 21.6 mol% and less than 54.5 mol% of units derived from 1-alkene,
It is a copolymer characterized by having a sea-island structure consisting of a sea phase and an island phase, and a diameter index of the island phase being 100 nm or less.
In the copolymer described in <1>, a unit derived from 1-alkene contained in more than 21.6 mol% and less than 54.5 mol% can contribute to improvement in toughness, and a unit derived from cycloolefin is It is believed that a sea-island structure comprising an sea phase and an island phase having a diameter index of 100 nm or less, which can contribute to the improvement of optical properties and heat resistance, can contribute to the improvement of toughness.
In the present invention, “island phase” refers to a domain-like closed region which can be confirmed when the cut surface of the copolymer is observed in the phase mode of an atomic force microscope (AFM). It is defined that the length (diameter) of the longest line segment connected by two points of the circumference forming the outline of the closed region is 10 nm or more.
In the present invention, the “diameter index” of the island phase is an arbitrary square region of 3 μm on a side of the cut surface of the copolymer observed in the phase mode of an atomic force microscope, It refers to a value obtained as an average of the diameters of 20 points (in the case where the number of island phases present is 20 points or less, all points) sequentially selected from the island phases having a large diameter among the existing island phases.
<2> The copolymer according to <1>, wherein the total light transmittance is 85% or more and the haze is 3.0% or less.
<3> The <1> or <1> or <1>, wherein the breaking strain measured by a tensile test with a temperature of 25 ° C., a chucking distance of 10 mm and a tensile speed of 10 mm / min is punched into a dumbbell-shaped test piece. It is a copolymer as described in 2>.
<4> The number average molecular weight is 2.50 × 10 ⁴ or more and 1.10 × 10 ⁵ or less, and the weight average molecular weight is 5.00 × 10 ⁴ or more and 1.60 × 10 ⁵ or less. It is a copolymer in any one of>-<3>.
<5> A copolymer of a cycloolefin and a 1-alkene, which comprises more than 21.6 mol% and less than 54.5 mol% of units derived from 1-alkene,
It has a sea-island structure consisting of a sea phase and an island phase, and the diameter index of the island phase is 100 nm or less. It is a manufacturing method of the copolymer characterized by the above.
<6> The method for producing a copolymer according to <5>, wherein the 1-alkene is 1-octene.
<7> A sheet molded article comprising at least the copolymer according to any one of <1> to <4>.

  According to the present invention, the above-mentioned various problems in the prior art can be solved, and the above object can be achieved, and a copolymer excellent in toughness while having high optical properties and heat resistance, and such a copolymer A method of manufacturing can be provided.

It is a schematic diagram of the image of the cross section of the film using the copolymer of this invention observed with an atomic force microscope. It is a schematic diagram of the image of the cross section of the film using the copolymer of one comparative example observed by an atomic force microscope. It is a schematic diagram of the image of the cross section of the film using the copolymer of another comparative example observed with an atomic force microscope. It is a schematic diagram of the image of the cross section of the film using the copolymer of the other comparative example observed with an atomic force microscope.

(Copolymer)
The copolymer of the present invention is, as described above, a copolymer of cycloolefin and 1-alkene, that is, a copolymer comprising a unit derived from cycloolefin and a unit derived from 1-alkene. In addition, the copolymer of the present invention is characterized by having a specific sea-island structure consisting of a sea phase and an island phase.
Hereinafter, the copolymer of the present invention will be described in detail.

<A unit derived from cycloolefin>
The copolymer of the present invention contains, as the first monomer unit, a unit derived from cycloolefin. Here, in the present invention, “cycloolefin” refers to a compound having an alicyclic structure formed of carbon atoms and having a carbon-carbon double bond in the alicyclic ring structure. In addition, the cycloolefin may have any substituent.

There is no restriction | limiting in particular as a cycloolefin which can form the unit derived from the said cycloolefin, According to the objective, it can select suitably, For example, a norbornene-type compound, a monocyclic cycloolefin, etc. are mentioned. Here, the norbornene-based compound is a compound containing a norbornene ring. The norbornene-based compound is not particularly limited and may be appropriately selected according to the purpose. Examples thereof include 2-rings such as 2-norbornene and norbornadiene, and tri-rings such as dicyclopentadiene and dihydrodicyclopentadiene, Tetracycles such as tetracyclododecene, ethylidene tetracyclododecene and phenyltetracyclododecene, and pentacycles such as tricyclopentadiene and the like. These may be used alone or in combination of two or more.
Among these, as the cycloolefin capable of forming a unit derived from the cycloolefin, a point to effectively improve the heat resistance of the obtained copolymer, a point to suppress light absorption, and a coweight with 1-alkene 2-norbornene is preferred in that coalescence can be made amorphous.

The proportion of units derived from cycloolefin in the copolymer of the present invention is not particularly limited as long as it is 45.5 mol% or more and 78.4 mol% or less, and can be appropriately selected depending on the purpose. 51.1 mol% or more and 56.7 mol% or less is preferable.
If the proportion of units derived from cycloolefin in the copolymer is less than 45.5 mol%, the copolymer can not have sufficiently high heat resistance and transparency, and the size of the island phase becomes large. With too much, the toughness may also be reduced. In addition, if the proportion of units derived from cycloolefin in the above-mentioned copolymer is more than 78.4 mol%, an island phase of good size is formed to make the toughness of the copolymer sufficiently high. Can not. On the other hand, when the proportion of units derived from cycloolefin in the copolymer is within the preferable range, the copolymer has a stable sea-island structure having an island phase of a good size, and the heat resistance of the copolymer It is advantageous in that the transparency and the toughness can be synergistically improved.
In addition, the ratio of the unit derived from the cycloolefin in a copolymer can be calculated | required from the < ¹³ > C-NMR chart of a copolymer.

<a unit derived from 1-alkene>
The copolymer of the present invention contains, as a second monomer unit, a unit derived from 1-alkene. Here, in the present invention, “1-alkene” has the same meaning as an α-olefin, that is, at least one of alkenes (olefins) in the α position (between the carbon at the end and the carbon adjacent thereto). Alkene (olefin) having a heavy bond, which may be linear or branched.

The 1-alkene which can form a unit derived from the 1-alkene is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include ethylene, propylene, 1-butene, 1-pentene, and 1- Hexene, 4-methyl-1-pentene, 1-heptene, 3-methyl-1-hexene, 4-methyl-1-hexene, 5-methyl-1-hexene, 1-octene, 3,4-dimethyl-1-ene Hexene, 1-nonene, 3,5,5-trimethyl-1-hexene, 1-decene, and the like. These may be used alone or in combination of two or more.
Among these, as 1-alkene which can form a unit derived from the 1-alkene, 1-hexene, from the point of further improving the toughness of the copolymer and the point that the decrease in heat resistance is relatively small 1-octene is preferred, and 1-octene is more preferred.

The proportion of units derived from 1-alkene in the copolymer of the present invention is not particularly limited as long as it is more than 21.6 mol% and less than 54.5 mol%, and can be appropriately selected according to the purpose. However, 43.3 mol% or more and 48.9 mol% or less are preferable.
If the proportion of units derived from 1-alkene in the copolymer is 21.6 mol% or less, an island phase having a good size can not be formed, and the toughness of the copolymer can not be made sufficiently high. . In addition, when the proportion of units derived from 1-alkene in the copolymer is 54.5 mol% or more, the copolymer can not have sufficiently high heat resistance and transparency, and the size of the island phase The toughness may also be reduced by the fact that is too large. On the other hand, when the proportion of units derived from 1-alkene in the copolymer is any within the above-mentioned preferable range and the above-mentioned more preferable range, a stable sea-island having an island phase of a good size in the copolymer It is advantageous in that it can provide a structure and synergistically improve the heat resistance, transparency and toughness of the copolymer.
The proportion of units derived from 1-alkene in the copolymer can be determined from the ¹³ C-NMR chart of the copolymer.

Sea-island structure
The copolymer of the present invention comprises the unit derived from the cycloolefin and the unit derived from the 1-alkene in the above ratio, and has a specific sea-island structure consisting of a sea phase and an island phase It is characterized by Surprisingly, the present inventors maintained heat resistance and transparency by the copolymer of cycloolefin and 1-alkene having a specific sea-island structure consisting of the above-mentioned sea phase and island phase. It was found that the flexibility and toughness can be dramatically improved.
In the sea-island structure of the copolymer of the present invention, usually, units derived from cycloolefin form a sea phase (hard segment) and units derived from 1-alkene form an island phase (soft segment). Do.
Here, in the present invention, the “island phase” is a domain-like closed region which can be confirmed when the cut surface of the copolymer is observed in the phase mode of an atomic force microscope, and the closed region The length (diameter) at which the line segment connected by the two points of the circumference forming the outline of the line is the longest is defined as 10 nm or more. Therefore, a copolymer in which even one closed region having a diameter of 10 nm or more is observed can be recognized as "having a sea-island structure consisting of a sea phase and an island phase".

  There is no restriction | limiting in particular as a shape of the island phase in the sea-island structure of the said copolymer, According to the objective, it can select suitably. For example, examples of the shape of the island phase include a circle, an ellipse, a rectangle, a rounded rectangle, a combination thereof, and the like, and among these, the circle and the ellipse are preferable.

There is no restriction | limiting in particular as a density of the island phase observed from the cut surface of the said copolymer, According to the objective, it can select suitably, However, From a viewpoint of improving the toughness of a copolymer effectively, The number of island phases in a 3 μm square region is preferably 500 to 100,000, more preferably 500 to 10,000, and particularly preferably 500 to 1,000.
The number of island phases in the square region of 3 μm on a side is arbitrarily selected three square regions of 3 μm on a side in the cut surface of the copolymer observed in the phase mode of atomic force microscope, and this region It can be recognized by counting the number of island phases present in each and calculating their average value.

Diameter index of island phase in the sea-island structure of the copolymer (A square region of 3 μm on a side is arbitrarily selected among cut surfaces of the copolymer observed in the phase mode of atomic force microscope, and exists in this region Among the island phases to be collected, the value obtained as the average of the diameters of 20 points (in the case where the number of island phases present is 20 points or less, all points) selected in descending order of diameter is 100 nm or less There is no particular limitation as long as it is present, and can be appropriately selected depending on the purpose, but 50 nm or more and 100 nm or less is preferable, and 70 nm or more and 100 nm or less is more preferable.
If the diameter index of the island phase is more than 100 nm, there is a possibility that the toughness such as fracture strain or fracture stress in the copolymer can not be sufficiently improved. On the other hand, when the diameter index of the island phase is any of the preferable range and the more preferable range, the stress is dispersed to more surely express the improvement of the toughness and the flexibility of the copolymer, and the island phase is It is advantageous in that it is more clearly identified by an atomic force microscope.

<Properties of copolymer>
There is no restriction | limiting in particular as a total light transmittance of the said copolymer, Although it can select suitably according to the objective, 85% or more is preferable and 90% or more is more preferable. The optical properties of the copolymer are sufficiently high when the total light transmittance of the copolymer is in the above-mentioned preferable range and in the more preferable range, and the copolymer is used as a sheet molded article such as an optical film. It is advantageous at the point which can be used suitably.
In addition, the total light transmittance of a copolymer can be measured according to JISK7361 using the haze meter which can measure the transmittance | permeability simultaneously.

There is no restriction | limiting in particular as a haze of the said copolymer, Although it can select suitably according to the objective, 3.0% or less is preferable and 1.0% or less is more preferable. The optical properties of the copolymer are sufficiently high when the haze of the copolymer is in the above-mentioned preferable range and in the more preferable range, and the copolymer is suitably used for a sheet molded article such as an optical film. It is advantageous in that it can be done.
The haze of the copolymer can be measured according to JIS K7136 using a haze meter.

  The copolymer of the present invention preferably has a total light transmittance of 85% or more and a haze of 3.0% or less, from the viewpoint of making the optical properties sufficiently high. It is more preferable that the light transmittance is 90% or more and the haze is 1.0% or less.

From the viewpoint of enhancing the toughness, the copolymer is punched into a dumbbell-shaped test piece, and the strain at break measured by a tensile test at a temperature of 25 ° C., a chucking distance of 10 mm, and a tensile speed of 10 mm / min. It is preferably 15% or more, and more preferably 20% or more.
Further, from the viewpoint of making the copolymer high in toughness, the breaking stress measured by the above tensile test is preferably 20.0 MPa or more, and more preferably 25.0 MPa or more.
The dumbbell-shaped test piece has a width of at least 4.00 mm and a thickness of about 100 μm.

There is no restriction | limiting in particular as a glass transition temperature (Tg) of the said copolymer, Although it can select suitably according to the objective, From a viewpoint of improving heat resistance, 140 degreeC or more is preferable and 150 degreeC or more is more preferable. .
The glass transition temperature of the copolymer can be determined from the position of the downshift portion of the DSC curve obtained by a differential scanning calorimeter (DSC).

There is no restriction | limiting in particular as a number average molecular weight (Mn) of the said copolymer, Although it can select suitably according to the objective, From a viewpoint of improving a softness | flexibility and a moldability, 2.50 x 10 ⁴ or more 1.10 × 10 ⁵ or less is preferable, and 4.00 × 10 ⁴ or more and 1.10 × 10 ⁵ or less are more preferable.
In addition, the number average molecular weight of a copolymer can be measured as a standard polystyrene conversion value by gel permeation chromatography (GPC method).

There is no restriction | limiting in particular as a weight average molecular weight (Mw) of the said copolymer, Although it can select suitably according to the objective, From a viewpoint of improving a softness | flexibility and film-formability, it is 5.00x10. ⁴ or more and 1.60 × 10 ⁵ or less are preferable, and 8.00 × 10 ⁴ or more and 1.60 × 10 ⁵ or less are more preferable.
In addition, the weight average molecular weight of a copolymer can be measured as a standard polystyrene conversion value by gel permeation chromatography (GPC method).

The copolymer of the present invention has a number average molecular weight of 2.50 × 10 ⁴ or more and 1.10 × 10 ⁵ or less, and a weight average molecular weight of from the viewpoint of improving flexibility and dispersibility. The number average molecular weight is preferably 5.00 × 10 ⁴ or more and 1.60 × 10 ⁵ or less, the number average molecular weight is 4.00 × 10 ⁴ or more and 1.10 × 10 ⁵ or less, and the weight average molecular weight is 8.00 It is more preferable that x 10 ⁴ or more and 1. 60 x 10 ⁵ or less.

(Method of producing copolymer)
The process for producing the copolymer of the present invention is a copolymer of cycloolefin and 1-alkene, which comprises more than 21.6% by mole and less than 54.5% by mole of a unit derived from 1-alkene, which comprises: And an island phase having a sea-island structure, and the diameter index of the island phase is 100 nm or less. This copolymer is as described above. Specifically, the method for producing the copolymer of the present invention is not particularly limited as long as the copolymer having the above-described aspect can be produced, and can be appropriately selected according to the purpose.

  A sea-island structure consisting of a sea phase and an island phase, wherein the diameter of the island phase is 100 nm or less is, for example, a block structure or a gradient structure (transfer from one end to the other end It is considered that it can be confirmed in the copolymer having a structure in which the polymerization proceeds so that the composition ratio of the monomer units in the copolymer gradually changes.

The copolymer of cycloolefin and 1-alkene having the block structure or the gradient structure described above is, for example, cycloolefin as a monomer capable of forming the first monomer unit in a hydrocarbon-based organic solvent, and It can be produced by adding 1-alkene as a monomer capable of forming a second monomer unit and reacting these monomer units using a group 4 transition metal complex as a polymerization catalyst. .
Hereinafter, this manufacturing method will be described in detail as an example.

  There is no restriction | limiting in particular as said hydrocarbon type organic solvent, According to the objective, it can select suitably, For example, normal butane, isobutane, normal pentane, isopentane, hexane, heptane, octane, cyclohexane, cycloheptane, benzene, Toluene, xylene and the like can be mentioned.

There is no restriction | limiting in particular as said Group 4 transition metal complex, Although it can select suitably according to the objective, Preferably, following General formula (1):
(Wherein, R ^{1 to} R ¹¹ each independently represent hydrogen, a C _{1 to} C ₁₀ alkyl group, a halogen atom and an aryl group optionally having a C _{1 to} C ₁₀ substituent, or a halogen atom And a silyl group which may have a C _{1 to} C ₁₀ substituent, and form a cyclic structure on R ⁵ -R ⁶ , R ⁶ -R ⁷ , R ⁸ -R ⁹ and R ⁹ -R ¹⁰ And a molecule constituting them includes saturated hydrocarbon, unsaturated hydrocarbon and the like, and X ¹ and X ² each independently represent a C _{1 to} C ₁₀ alkyl group or a halogen atom And M is a half metallocene having a Group 4 transition metal represented by Group 4 transition metal). Specifically, M representing a Group 4 transition metal can be selected from titanium (Ti), zirconium (Zr) and hafnium (Hf). In the polymerization reaction using this half metallocene as a polymerization catalyst, compared with the case of using other polymerization catalysts, a unit derived from cycloolefin which is an alicyclic structure is easily formed in the initial stage, and in the latter stage a chain structure Since a unit derived from a certain 1-alkene tends to be formed (that is, the difference in reactivity of monomers can be more effectively utilized), inter alia, a copolymer having a gradient structure can be obtained. .

  In addition, this half metallocene can exhibit high copolymerization activity even for cycloolefins and 1-alkenes having different bulk heights, and in addition, the number of carbon atoms conventionally difficult to be polymerized is large (for example, 6 carbon atoms) Even when the above 1) -alkene is used as a monomer, sufficiently high copolymerization activity can be exhibited. Therefore, a copolymer having a gradient structure can be obtained by using this half metallocene as a polymerization catalyst while using any cycloolefin and, for example, 1-octene having 8 carbon atoms as a 1-alkene as monomers. it can. And since such a copolymer preferably has a sea-island structure consisting of a sea phase and an island phase, heat resistance and transparency are maintained as compared with the conventional copolymer of cycloolefin and 1-alkene, Flexibility and toughness are dramatically high.

  Examples of the Group 4 transition metal possessed by the half metallocene include titanium (Ti), zirconium (Zr), and hafnium (Hf), and among these, copolymers having a good number average molecular weight and weight average molecular weight It is preferable that it is titanium (Ti) from a viewpoint of obtaining easily. That is, the half metallocene is preferably half titanocene.

  In the polymerization, alkyl introduction agents such as trinolmal octylaluminum, trinolmalhexylaluminum, triisobutylaluminum, triethylaluminum, trimethylaluminum, triphenylmethylium tetrakis (pentafluorophenyl) borate, tris (pentafluorophenyl) borane Cocatalysts such as methylaluminoxane, and other additives can also be used. Here, the alkyl introduction agent can also function as a scavenger (scavenger) of impure ions.

  In the production of the copolymer of cycloolefin and 1-alkene according to the present invention, the diameter index of the island phase is the ratio of the unit derived from cycloolefin introduced into the copolymer and the unit derived from 1-alkene It is possible to adjust appropriately by changing.

(Sheet molded body)
The sheet molded article of the present invention is characterized by using at least the above-mentioned copolymer. There is no restriction | limiting in particular as a manufacturing method of the said sheet molded object, According to the objective, it can select suitably, For example, the said copolymer made into powder form is filled in a mold, and it is predetermined pressure and predetermined temperature. A method of producing by vacuum pressing, dissolving the copolymer in a suitable organic solvent, filtering out insoluble matter if necessary, and casting the obtained solution to a uniform thickness on a substrate, A method of producing by drying in an oven to remove the solvent, and the like can be mentioned. The sheet molded body is excellent in toughness while having high optical properties and heat resistance, and is suitably used for an optical film, a lens film, a substrate of a transparent conductive film, a barrier film, a protective film, a film for packaging, etc. be able to.

  Next, the present invention will be more specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
<Preparation of raw materials>
As a solvent, benzophenone and metallic sodium pieces are added to a toluene reagent, reflux and distillation are performed, and further metallic sodium pieces are added and stored in a storage bottle attached to a cock (hereinafter referred to as "dehydrated toluene" There was a).
As the cycloolefin, add an appropriate amount of calcium hydride to the 2-norbornene reagent, reflux and distill, add the above-mentioned dehydrated toluene to adjust to an appropriate concentration, and put it in an eggplant flask with a cockle under an inert gas. What was stored in the dark (hereinafter sometimes referred to as "treated 2-norbornene") was used.
As 1-alkene, an appropriate amount of calcium hydride is added to 1-octene reagent, reflux and distillation are performed, the above-mentioned dehydrated toluene is added to adjust to an appropriate concentration, and it is put into an eggplant flask with a cockle under inert gas. It was used after dark storage (hereinafter sometimes referred to as "processed 1-octene").
The half-titanocene as a halfmethanocene which is a catalyst for polymerization is obtained by synthesizing and purifying it in a degassed and dried glass apparatus equipped with a nitrogen-vacuum line (manifold) [t-BuNSiMe ₂ Flu] TiMe ₂ (In the above general formula (1), R ¹ is a tert-butyl group, R ² and R ³ are methyl groups, R ^{4 to} R ¹¹ are hydrogen, X ¹ and X ² Is a methyl group and M is titanium, it was put in a cocked Schlenk tube under inert gas, stored in a -30 ° C freezer, and used after seasoning to room temperature.
As triphenyl methylium tetrakis (pentafluorophenyl) borate which is a co-catalyst for polymerization, a reagent "T2863" manufactured by Tokyo Chemical Industry Co., Ltd. is put in a Schlenk tube under inert gas and stored at room temperature. It was.
Tolural octyl aluminum, which is an alkyl introducing agent that can also function as a scavenger, is prepared by adding "TNOAL" manufactured by Tosoh Finechem Co., Ltd. to an appropriate amount of toluene to prepare a solution, and with Teflon (registered trademark) cap under inert gas What was stored in the Schlenk tube was used.

<Preparation of copolymer of cycloolefin and 1-alkene>
To the two-necked flask equipped with a three-way cock and a magnetic stirrer, add the above-mentioned dehydrated toluene and tributyloctylaluminum, and further, treat the treated 2-norbornene (1 in the formula below) and the treated 1-octene (the formula below The contents of 2) were added to the respective desired amounts and thoroughly stirred to obtain a homogeneous solution. Then, half titanocene (3 in the following formula) and triphenylmethylium tetrakis (pentafluorophenyl) borate are accurately weighed in separate Schlenk tubes under inert gas, and dehydrated toluene is added to disperse them. Each dispersion was obtained. Then, these dispersions are mixed, and after temporarily preparing a solution containing [t-BuNSiMe ₂ Flu] Ti ⁺ Me as a polymerization active species, polymerization is carried out by adding it to the homogeneous solution kept at 25 ° C. It was started. After 2 hours, the reacted solution was dropped into methanol hydrochloric acid (0.5 N) as a poor solvent, and the deposited precipitate was washed with methanol. Next, this was filtered and then dried under reduced pressure to obtain a powder of a copolymer of cycloolefin and 1-alkene (4 in the following formula). This series of polymerization reactions can be represented by the following formula.
The ratio of each monomer unit, and the number average molecular weight (Mn) and the weight average molecular weight (Mw) of the copolymer of cycloolefin and 1-alkene were measured by the method described later. The results are shown in Table 1.

<Preparation of film>
An aluminum plate with a thickness of 100 μm was used as a mold, and the powder of the copolymer of cycloolefin and 1-alkene obtained as described above was filled therein. Then, vacuum pressing was performed by a thermal vacuum press under the conditions of pressure: 10 MPa, temperature: 260 ° C., and time: 15 minutes. Thereafter, the resultant was quenched with ice water to obtain a film (film-formed product) having a thickness of about 100 μm.
The mechanical properties, thermal properties and optical properties of this film were evaluated by the methods described below. Moreover, the cross section of this film was observed by the method described later.

-Ratio of each monomer unit in copolymer-
Regarding the copolymer of cycloolefin and 1-alkene obtained as described above, a unit derived from cycloolefin and a unit derived from cycloolefin from a ¹³ C-NMR chart obtained by a nuclear magnetic resonance apparatus “JNM-ECS 400” manufactured by JEOL Ltd. The proportion of units derived from 1-alkene was determined. The results are shown in Table 1.

-Number average molecular weight (Mn) and weight average molecular weight (Mw) of copolymer-
For the copolymer of cycloolefin and 1-alkene obtained as described above, using GPC “GPC-101” manufactured by SHODEX, using a differential refractometer as a detector, the number as a standard polystyrene equivalent value Average molecular weight (Mn) and weight average molecular weight (Mw) were measured. Moreover, molecular weight distribution (Mw / Mn) was also calculated from these values. The results are shown in Table 1.

-Mechanical properties of film-
The film having a thickness of about 100 μm obtained as described above was punched into a dumbbell shape having a width of 4.00 mm, and a film without craze or deflection was used as a test piece. Then, using a tester "AUTOCOM / AC-50" manufactured by TS SE Co., Ltd. and using a load cell rated 100 N, the temperature was 25 ° C., the chucking distance was 10 mm, and the tensile speed was 10 mm / min. A tensile test was performed to determine the breaking strain (%) and the breaking stress (MPa). The results are shown in Table 1. The larger the breaking strain and the larger the breaking stress, the better the toughness of the film and the copolymer.

-Thermal characteristics of film-
Among the films obtained as described above, 5 to 10 mg was taken as a sample in an aluminum pan and placed in a differential scanning calorimeter (DSC) manufactured by Seiko Instruments Inc. Then, as a first run, the sample was heated from room temperature to 300 ° C. at a rate of 20 ° C./min under a nitrogen stream. Next, after the sample was cooled, the same heating operation was performed as a second Run. A DSC curve was obtained from these operations, and the glass transition temperature (Tg) (° C.) was determined from the position of the downshift portion of this DSC curve. The results are shown in Table 1. It shows that a film and a copolymer are excellent in heat resistance, so that this glass transition temperature is large.

-Optical properties of film-
With respect to the film obtained as described above, the total light transmittance (%) according to JIS K7361 and the haze according to JIS K7136 according to JIS K7361 using a transmittance meter "NDH 7000SP" manufactured by Nippon Denshoku Co., Ltd. %) Was measured. The results are shown in Table 1. The larger the total light transmittance and the smaller the haze, the better the optical properties of the film and the copolymer.

-Observation of cross section of film-
The cross section of the film obtained as described above was observed with an atomic force microscope (AFM) “unit: SPA 340, probe station: SPI 3800 N, cantilever: SI-DF 40” manufactured by Hitachi High-Technologies Corporation. In addition, when observing the cross section of the film, the measurement mode of SIS-DFM was set, and a shape image and a phase image were simultaneously obtained.A square with a side of 3 μm of the cross section of the film observed with an atomic force microscope A schematic view of an image of a region is shown as FIG.
From this square area, the island phase defined above (that is, a closed area in the form of a domain, and the length of a line connecting at two points on the periphery forming the outline of the closed area is at least 10 nm Of the presence of the
Moreover, 20 points were selected in order from the thing with a large diameter defined above among the island phases which exist in this square area | region, and the average of these diameters was calculated | required as a diameter index of an island phase. Furthermore, three square regions each having a side of 3 μm were arbitrarily selected, the number of island phases present in this region was counted, and the average value thereof was determined as the number of island phases in the square region having a side 3 μm. The results are shown in Table 1.
In addition, the aspect (the presence or absence, diameter index, the number of objects per unit area, etc.) in a film and the aspect of the island phase in the copolymer which is a raw material of the said film can be recognized as equivalent.

(Examples 2 to 5)
In the preparation of the copolymer of cycloolefin and 1-alkene of Example 1, the amounts of treated 2-norbornene and treated 1-octene are determined by the proportion of units derived from cycloolefin in the resulting copolymer and Copolymers and films were prepared in the same manner as in Example 1 except that the proportion of units derived from 1-alkene was changed as shown in Table 1, and various measurements and the like were performed. The results are shown in Table 1. Moreover, all show the schematic diagram of the image of the square area | region of 3 micrometers of one side of the cross section of the film which concerns on Examples 2-5 observed by an atomic force microscope as FIG.

(Comparative Examples 1 and 2)
In the preparation of the copolymer of cycloolefin and 1-alkene of Example 1, the amounts of treated 2-norbornene and treated 1-octene are determined by the proportion of units derived from cycloolefin in the resulting copolymer and Copolymers and films were prepared in the same manner as in Example 1 except that the proportion of units derived from 1-alkene was changed as shown in Table 1, and various measurements and the like were performed. The results are shown in Table 1. Moreover, the schematic diagram of the image of the square area of 3 micrometers of one side of the cross section of the film which concerns on the comparative examples 1 and 2 observed by an atomic force microscope is shown as FIG.2, 3 respectively.

(Comparative example 3)
In Example 1, instead of using the prepared powder of the copolymer of cycloolefin and 1-alkene, a resin pellet of “TOPAS 6017” (copolymer of norbornene and ethylene) manufactured by Polyplastics Co., Ltd. A film was prepared in the same manner as in Example 1 except that it was used, and various measurements and the like were performed. In addition, about various molecular weight and molecular weight distribution, column temperature was set to 140 degreeC using GPC "Alliance GPC2000 type | mold" made from Waters, and it obtained as a standard polystyrene conversion value using a differential refractometer as a detector. The results are shown in Table 1. Moreover, the schematic diagram of the image of the square area | region of 3 micrometers of one side of the cross section of the film which concerns on the comparative example 3 observed by an atomic force microscope is shown as FIG.

(Comparative example 4)
In Example 1, a mechanical film was prepared in the same manner as in Example 1, except that a film of “ZF-16” (cycloolefin polymer (COP)) manufactured by Nippon Zeon Co., Ltd. was used as it was, instead of the prepared film. Properties, thermal properties and optical properties were evaluated. The results are shown in Table 1.

  From Table 1, it is a copolymer of cycloolefin and 1-alkene that contains more than 21.6% by mole and less than 54.5% by mole of units derived from 1-alkene, and is a sea-island structure composed of sea phase and island phase The copolymer of Examples 1 to 5 having a diameter index of the island phase of 100 nm or less and a film as a sheet molded product using the same have excellent optical characteristics, heat resistance and toughness. I understand that. As can be seen from FIG. 1, most of the island phases according to Examples 1 to 5 had a circular shape and an elliptical shape.

On the other hand, in Comparative Examples 1 and 4, since the copolymer does not have at least an island phase, mechanical properties such as fracture strain are lower and toughness is lower than that of the copolymer of the present invention and a film using the same. It turns out that it is inadequate. In particular, in Comparative Example 1, since the unit derived from 1-alkene is 21.6 mol% or less, it is understood that the strain at break is lower.
Further, in Comparative Example 2, although the copolymer has an island phase, at least the diameter index of the island phase significantly exceeds 100 nm (see also FIG. 3), the copolymer of the present invention And compared with the film using this, it turns out that mechanical characteristics, such as a breaking strain and a breaking stress, are low and toughness is inadequate. In addition, in Comparative Example 2, the unit derived from 1-alkene is 54.5 mol% or more, so it is understood that the thermal characteristics and the optical characteristics are also insufficient.
Furthermore, in Comparative Example 3, although the copolymer has a domain-like closed region, its diameter is less than 10 nm and it can not be said that it has an island phase (see also FIG. 4). Compared with the copolymer of the invention and a film using the same, it is understood that mechanical properties such as strain at break are low and toughness is insufficient.

  According to the present invention, a copolymer excellent in toughness can be provided while having high optical properties and heat resistance, and such a copolymer includes an optical film, a lens film, a transparent conductive film substrate, and a barrier film. It can be suitably used for the production of sheet moldings such as protective films and packaging films.

Claims (6)

It is a molded object which consists of a copolymer of cycloolefin and 1-alkene which contains a unit derived from 1-alkene by more than 21.6 mol% and 54.5 mol%,
The shaped body characterized in that the copolymer has a sea-island structure consisting of a sea phase and an island phase, and the diameter index of the island phase is 100 nm or less.   The molded article according to claim 1, wherein the copolymer has a total light transmittance of 85% or more and a haze of 3.0% or less.   The molding according to claim 1 or 2, wherein a breaking strain measured by a tensile test which is punched into a dumbbell-shaped test piece, a temperature of 25 ° C, a chucking distance of 10 mm and a tensile speed of 10 mm / min is 15% or more. body. The copolymer has a number average molecular weight of 2.50 × 10 ⁴ or more and 1.10 × 10 ⁵ or less, and a weight average molecular weight of 5.00 × 10 ⁴ or more and 1.60 × 10 ⁵ or less. The molded object in any one of Claims 1-3. It is a manufacturing method of the molded object in any one of Claims 1-4, Comprising: The said copolymer is following General formula (1):
(Wherein, R ^{1 to} R ¹¹ each independently represent hydrogen, a C _{1 to} C ₁₀ alkyl group, a halogen atom and an aryl group optionally having a C _{1 to} C ₁₀ substituent, or a halogen atom And a silyl group which may have a C _{1 to} C ₁₀ substituent, and form a cyclic structure on R ⁵ -R ⁶ , R ⁶ -R ⁷ , R ⁸ -R ⁹ and R ⁹ -R ¹⁰ And X ¹ and X ² each independently represent a C _{1 to} C ₁₀ alkyl group or a halogen atom, and M represents a group 4 transition metal) A process for producing a molded article , comprising the steps of: obtaining a complex as a polymerization catalyst and reacting cycloolefin with 1-alkene ; and pressing the copolymer .   The method for producing a formed body according to claim 5, wherein the 1-alkene is 1-octene.