Cycloolefin polymer as well as preparation method and application thereof

Abstract

The invention belongs to the field of high polymer materials, and particularly relates to a cycloolefin polymer as well as a preparation method and application thereof. The preparation method provided by the invention comprises the following steps: a) in the presence of a catalyst system, carrying out prepolymerization reaction on a polymeric monomer in a solvent to obtain a prepolymer; the polymeric monomer comprises norbornene cycloolefin, and the viscosity of the prepolymer at 25 DEG C is 3-300 cps; and b) continuously mixing the prepolymer with a polymerization monomer for polymerization reaction, and then carrying out hydrogenation reaction on a polymerization reaction product to obtain the cycloolefin polymer. The cycloolefin polymer with excellent tensile strength, tensile modulus and film thickness uniformity can be obtained by adopting a two-step method for polymerization and controlling the viscosity of the prepolymer.

Description

Technical Field

[0001] The present invention belongs to the field of polymer materials, and particularly relates to a cycloolefin polymer, a preparation method thereof, and an application thereof. Background Art

[0002] A polymer obtained by hydrogenating a ring-opening polymer (hydrogenated ring-opening polymer) obtained by ring-opening polymerization of a monomer composition containing norbornene has excellent heat resistance, transparency, light resistance, water absorption resistance, moisture resistance, chemical resistance, solvent resistance, dielectric properties, low birefringence, etc., and is widely used as an optical material, a medical device, an electrical insulation material, a device for processing electronic components, etc.

[0003] Therefore, regarding cycloolefin polymers containing structural units derived from norbornene, research has been continuously carried out to further improve their properties.

[0004] Patent Document 1 (Japanese Patent Laid-Open No. 2014-148634) describes the following norbornene-based cycloolefin polymer: it contains 1 to 15% by weight of structural units derived from norbornene-based monomers, 15 to 50% by weight of structural units derived from tetracyclododecene-based monomers, 50 to 90% by weight of structural units derived from methylenebridged tetrahydrofluorene-based monomers, and the branching index is 0.7 to 0.9.

[0005] However, in recent years, with the increasing demands for imaging, photographing, and image display, cycloolefin polymers used in molded products such as optical films are required to have stronger optical anisotropy, higher optical transmittance, excellent thermal stability, and mechanical properties. Specifically, when processed, they are required to have not only good ductility, but also a uniform film thickness and a smaller film thickness difference, so as to more effectively handle common display problems such as light scattering and light reflection.

[0006] Patent Document 2 (Japanese Patent Laid-Open No. 2021-508990) describes a cycloolefin polymer containing 90% by mass or more of structural units derived from norbornene. By controlling specific properties in the structural units of norbornene (the proportion of isotactic dyads of the cis-1,3-cyclopentane structure unit is 0% or more and 30% or less, or 70% or more and 100% or less; the proportion of the trans-1,3-cyclopentane structure unit is 0.5% or more and 20% or less), a cycloolefin polymer with excellent ductility can be obtained. However, it is impossible to accurately and effectively control the film thickness uniformity, which greatly limits its application in retardation films, polarizing films, large-screen light guide plates, LCD panels, etc. On the other hand, in the catalyst solution synthesis stage during its production process, an extremely low temperature (-78°C) is required to control its reaction activity. During polymerization, the temperature needs to be raised to a high temperature for reaction, and the polymerization time is relatively long. The energy consumption in industrial production is large, which is not conducive to continuous production.

[0007] Therefore, how to find a more suitable production method, how to more effectively solve the problem of film thickness uniformity in the process of optical film processing, so that the cycloolefin polymer and the resin composition containing the cycloolefin polymer have more excellent ductility and processability, while facilitating industrial application and meeting the various requirements of industrial application, has become one of the urgent problems to be solved by many front-line researchers in the industry. Summary of the Invention

[0008] In view of this, the purpose of the present invention is to provide a cycloolefin polymer, a preparation method and an application thereof. By using the method provided by the present invention, a cycloolefin polymer with high tensile strength, high tensile modulus and excellent film thickness uniformity can be prepared, which has good application prospects in the field of optical films.

[0009] The present invention provides a preparation method of a cycloolefin polymer, comprising the following steps:

[0010] a) In the presence of a catalyst system, the polymerization monomer undergoes a prepolymerization reaction in a solvent to obtain a prepolymer;

[0011] The polymerization monomer comprises a norbornene-based cycloolefin, and the viscosity of the prepolymer at 25 °C is 3-300 cps;

[0012] b) The prepolymer continues to be mixed with the polymerization monomer for a polymerization reaction, and then the polymerization reaction product is subjected to a hydrogenation reaction to obtain a cycloolefin polymer.

[0013] Preferably, the temperature of the prepolymerization reaction is 0-100 °C.

[0014] Preferably, the time of the prepolymerization reaction ≤ 200 min.

[0015] Preferably, the catalyst system is a homogeneous or heterogeneous catalyst system capable of catalyzing the ring-opening polymerization reaction of the polymerization monomer.

[0016] Preferably, a molecular weight regulator is further added to the reaction system of the prepolymerization reaction and / or the polymerization reaction; the molecular weight regulator includes a non-diene vinyl compound and / or a diene compound, and the non-diene vinyl compound is an organic compound having a vinyl group and not belonging to a diene compound.

[0017] Preferably, in step a), the solvent includes one or more of toluene, cyclohexane, methylcyclohexane and tetrahydrofuran.

[0018] Preferably, in step a), the polymerization monomer comprises a norbornene-based cycloolefin having the structure shown in formula (I);

[0019]

[0020] In formula (I), n is 0 or 1, m is an integer of 0 or more than 1, and R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 -C 30 hydrocarbyl group having a linking group containing oxygen, nitrogen, sulfur or silicon, or a polar group having a linking group containing oxygen, nitrogen, sulfur or silicon.

[0021] Preferably, in formula (I), R 1 and R 2 , R 3 and R 4 , or R 2 and R 3 are bonded to each other to form a carbocyclic ring or a heterocyclic ring;

[0022] The carbocyclic ring or heterocyclic ring is a monocyclic structure, or is fused with other rings to form a polycyclic structure;

[0023] The carbocyclic ring or heterocyclic ring is an aromatic ring or a non-aromatic ring.

[0024] The present invention provides a cycloolefin polymer prepared by the preparation method according to the above technical solution.

[0025] The present invention provides an optical resin composition containing the cycloolefin polymer according to the above technical solution.

[0026] Compared with the prior art, the present invention provides a cycloolefin polymer, a preparation method and an application thereof. The preparation method provided by the present invention includes the following steps: a) in the presence of a catalyst system, a prepolymerization reaction is carried out on a polymerization monomer in a solvent to obtain a prepolymer; the polymerization monomer includes a norbornene-based cycloolefin, and the viscosity of the prepolymer at 25 °C is 3 to 300 cps; b) the prepolymer is continuously mixed with the polymerization monomer for a polymerization reaction, and then the polymerization reaction product is subjected to a hydrogenation reaction to obtain a cycloolefin polymer. The present invention surprisingly finds that when the preparation process is adjusted to a two-step polymerization, the viscosity of the prepolymer in the preparation process will affect the product quality of the optical products made of the cycloolefin polymer, especially is closely related to indexes such as the elongation at break, tensile strength, tensile modulus, film thickness uniformity of the product. Therefore, by adopting a two-step polymerization and controlling the viscosity of the prepolymer, the present invention can obtain a cycloolefin polymer with excellent tensile strength, tensile modulus and film thickness uniformity.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] (1) By adopting a two-step polymerization process and regulating the polymerization process, high-performance cycloolefin polymers and their resin molded articles can be prepared with high efficiency, and the obtained optical articles have high tensile strength, high tensile modulus and excellent film thickness uniformity;

[0029] (2) By monitoring the viscosity of the prepolymer, subtle differences in the manufacturing process can be quickly detected, and effective supervision for improving product quality can be achieved at low cost, significantly reducing the defective rate. Detailed implementation manners

[0030] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0031] The present invention provides a method for preparing a cycloolefin polymer, comprising the following steps:

[0032] a) In the presence of a catalyst system, the polymerization monomer undergoes a prepolymerization reaction in a solvent to obtain a prepolymer;

[0033] b) The prepolymer continues to be mixed with the polymerization monomer for a polymerization reaction, and then the polymerization reaction product is subjected to a hydrogenation reaction to obtain a cycloolefin polymer.

[0034] In the preparation method provided by the present invention, in step a), the viscosity of the prepolymer at 25 °C is 3 to 300 cps, preferably 3 to 250 cps, more preferably 5 to 220 cps, and most preferably 5 to 200 cps. In the present invention, after the above prepolymer is completely quenched, the viscosity of the sample is tested, and the preferred quenching agent is isopropanol.

[0035] In the preparation method provided by the present invention, in step a), the reason for controlling the viscosity of the prepolymer is that through research, it is found that: when the viscosity (25 °C) of the prepolymer is higher than 300 cps, in the second polymerization step, due to the high viscosity of the system, local temperature gradients are likely to occur, resulting in local gel reactions, leading to stress concentration points in the prepared cycloolefin polymer, reduced moldability, embrittlement and easy fracture, a significant decrease in the elongation at break of the polymer, and low flowability during film molding processing, resulting in large fluctuations in the thickness uniformity of the pressed film; when the viscosity of the prepolymer is lower than 3 cps, the prepolymer hardly undergoes prepolymerization. On the one hand, the second polymerization step cannot proceed normally and polymerization fails; on the other hand, if the second polymerization step can occur, but since the monomer concentration in the reaction system is much higher than the molecular weight regulator concentration, the rate of chain termination reaction cannot keep up with the rate of chain growth reaction at all, resulting in a low number-average molecular weight and a wide molecular weight distribution of the prepared cycloolefin polymer, thus affecting the tensile strength and tensile modulus of the finally prepared cycloolefin polymer optical product to decrease significantly, the product quality to deteriorate, and it is difficult to carry out effective production.

[0036] In the preparation method provided by the present invention, in step a), the polymerization monomer includes norbornene-based cycloolefins, preferably norbornene-based cycloolefins having the structure shown in formula (I);

[0037]

[0038] In formula (I), n is 0 or 1, m is 0 or an integer of 1 or more, R 1 、R 2 、R 3 and R 4 each independently represents a hydrogen atom, a halogen atom, a substituted or unsubstituted C 1 ~C 30 hydrocarbon group having a linking group containing oxygen, nitrogen, sulfur or silicon or a polar group having a linking group containing oxygen, nitrogen, sulfur or silicon. In the present invention, in formula (I), R 1 and R 2 , R 3 and R 4 , or R 2 and R 3 can be bonded to each other to form a carbocyclic ring or a heterocyclic ring; the carbocyclic ring or heterocyclic ring can be a monocyclic structure or can be fused with other rings to form a polycyclic structure; the carbocyclic ring or heterocyclic ring can be an aromatic ring or a non-aromatic ring.

[0039] In the preparation method provided by the present invention, in step a), the norbornene-based cycloolefin can more specifically be a norbornene-based compound without an aromatic ring, including: norbornene, 1-methyl-2-norbornene, 5-methyl-2-norbornene, 7-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-propyl-2-norbornene, 5-phenyl-2-norbornene, 5,6-dimethyl-2-norbornene, 5,5,6-trimethyl-2-norbornene, 5-chloro-2-norbornene, 5,5-dichloro-2-norbornene, 5-fluoro-2-norbornene, 5,5,6-trifluoro-6-trifluoromethyl-2-norbornene, 5-chloromethyl-2-norbornene, 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-n-propylidene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinyl-2-norbornene, 5-allyl-2-norbornene, 5,6-diethylidene-2-norbornene, 5-cyclohexenyl-2-norbornene, 2,5-norbornadiene and other bicyclic compounds; dicyclopentadiene (cyclopentadiene dimer), 1,2-dihydrodicyclopentadiene, 5,6-dihydrodicyclopentadiene and other tricyclic compounds; 1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-methyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-ethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2,3-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-hexyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-ethylidene-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-fluoro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 1,5-dimethyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-cyclohexyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2,3-dichloro-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene, 2-isobutyl-1,4,5,8-dimethano-1,2,3,4,4a,5,8,8a-octahydronaphthalene and other tetracyclic compounds; cyclopentadiene trimer and other pentacyclic compounds; cyclopentadiene tetramer and other heptacyclic compounds, etc., one or more than 2 kinds thereof; norbornene-based compounds containing an aromatic ring can also be used, for example: 5-phenyl-2-norbornene, 5-methyl-5-phenyl-bicyclo[2.2.1]hept-2-ene, 5-benzyl-bicyclo[2.2.1]hept-2-ene, 5-tolyl-bicyclo[2.2.1] Hept-2-ene [i.e., 5-(4-methylphenyl)-2-norbornene], 5-(ethylphenyl)-bicyclo[2.2.1]hept-2-ene, 5-(isopropylphenyl)-bicyclo[2.2.1]hept-2-ene, 5-methyl-5-carboxybenzyl bicyclo[2.2.1]hept-2-ene, 8-phenyl-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-methyl-8-phenyl-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-benzyl-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-tolyl-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(ethylphenyl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(isopropylphenyl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8,9-diphenyl-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(biphenyl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(β-naphthyl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(α-naphthyl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 8-(anthryl)-tetracyclo[4.4.0.12,5.17,10]-3-dodecene, 11-phenyl-hexamethylene[6.6.1.13,6.110,13.02,7.09,14]-4-heptadecene, 6-(α-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5-(anthryl)-bicyclo[2.2.1]-hept-2-ene, 5-(biphenyl)-bicyclo[2.2.1]-hept-2-ene, 5-(β-naphthyl)-bicyclo[2.2.1]-hept-2-ene, 5,6-diphenyl-bicyclo[2.2.1]-hept-2-ene, 9-(2-norbornen-5-yl)-carbazole, 1,4-methyl-1,4,4a,4b,5,8,8a,9a-octahydrofluorene, 1,4-methyl-1,4,4a,9a-tetrahydrofluorene, 1,4-methyl-8-methyl-1,4,4a,9a-tetrahydrofluorene, 1,4-methyl-8-chloro-1,4,4a,9a-tetrahydrofluorene, 1,4-methyl-8-bromo-1,4,4a,9a-tetrahydrofluorene, 1,4-methyl-1,4,4a,9a-tetrahydrothiophene, 1,4-methyl-1,4,4a,9a-tetrahydrocarbazole, 1,4-methyl-9-phenyl-1,4,4a,9a-tetrahydrocarbazole, 1,4-methyl-1,4,4a,5,10,10a-hexahydroanthracene, 7,10-methyl-6b,7,10,10a-tetrahydrofluoranthene, cyclopentadiene-acenaphthene adduct, a compound in which cyclopentadiene is further added to the cyclopentadiene-acenaphthene adduct, 11,12-benzo-pentacyclo[6.5.1.13,6.2,7.09,13]-4-Pentadecene, 11,12-benzo-pentacyclo[6.1]13,6.02,7.09,14]-4-hexadecene, 14,15-benzo-heptacyclo[8.7.0.12,9.14,7.111,17.03,8.012,16]-5-eicosene, etc. In the present invention, a norbornene-based cycloolefin can be used alone, or two or more thereof can be used in combination.

[0040] In the preparation method provided by the present invention, in step a), the polymerization monomer can be more specifically selected as a mixed monomer composed of methylene tetrahydrofluorene (MTF), tetracyclododecene (TCD), and norbornene (NB); wherein, the content of methylene tetrahydrofluorene in the mixed monomer is preferably 60-80 wt%, more preferably 70 wt%; the content of tetracyclododecene in the mixed monomer is preferably 15-30 wt%, more preferably 25 wt%; the content of norbornene in the mixed monomer is preferably 1-10 wt%, more preferably 5 wt%.

[0041] In the preparation method provided by the present invention, in step a), the catalyst system is a homogeneous or heterogeneous catalyst system capable of catalyzing the ring-opening polymerization of polymerization monomers. Preferably, the catalytic system is not particularly limited as long as it can ring-opening polymerize the polymerization monomers containing norbornene-based cycloolefins and can obtain high-performance cycloolefin polymers. From the perspective of efficiently preparing high-performance cycloolefin polymers, a ring-opening polymerization catalytic system that can easily control the viscosity of the prepolymer is preferred. Such catalyst systems include those composed of metal halides, nitrates or acetylacetone compounds and reducing agents among ruthenium, rhodium, palladium, osmium, iridium, platinum, etc.; metal halides or acetylacetone compounds selected from titanium, vanadium, zirconium, tungsten and molybdenum can also be used. In addition, as the ring-opening polymerization catalyst, in order to improve the catalyst activity, it is preferred to use in combination the complex catalyst containing transition metals of Group 6 of the periodic table and a cocatalyst other than the complex catalyst. As the cocatalyst, known organometallic compounds can be cited. As the organometallic compound, an organometallic compound of any of Groups 1, 2, 12, 13 and 14 of the periodic table having a hydrocarbon group with 1 to 20 carbon atoms is preferred, and an organolithium compound, an organomagnesium compound, an organozinc compound, an organoaluminum compound, an organotin compound are more preferred, and an organolithium compound and an organoaluminum compound are particularly preferred. As the organolithium compound, n-butyllithium, methyllithium, phenyllithium, neopentyllithium, tert-butylphenyl (Neophyl) lithium, etc. can be cited. As the organomagnesium compound, butylethylmagnesium, butyloctylmagnesium, dihexylmagnesium, ethylmagnesium chloride, n-butylmagnesium chloride, allylmagnesium bromide, neopentylmagnesium chloride, tert-butylphenylmagnesium chloride, etc. can be cited. As the organozinc compound, dimethylzinc, diethylzinc, diphenylzinc, etc. can be cited. As the organoaluminum compound, trimethylaluminum, triethylaluminum, triisobutylaluminum, diethylaluminum chloride, diethylethoxyaluminum, ethylaluminum dichloride, ethyldiethoxyaluminum, etc. can be cited. As the organotin compound, tetramethyltin, tetrakis(n-butyl)tin, tetraphenyltin, etc. can be cited. In addition, the cocatalyst can be used alone as one kind, or two or more kinds can be used in combination. In addition to the above two components, a third component can be added to further regulate the ring-opening polymerization activity. Such third components include aliphatic tertiary amines, aromatic tertiary amines, molecular oxygen, alcohols, haloalcohols, ethers, peroxides, carboxylic acids, acid anhydrides, acyl chlorides, esters, ketones, nitriles and other nitrogen-containing compounds, sulfur-containing compounds, halogen-containing compounds, molecular iodine, other Lewis acids, etc. Among them, alcohols and haloalcohols are preferred, and haloalcohols are more preferred. As specific examples of alcohols, n-propanol, n-butanol, n-hexanol, 2-butanol, isobutanol, isopropanol, tert-butanol, etc. can be cited. As specific examples of haloalcohols, 1,3-dichloro-2-propanol, 2-chloroethanol, 1-chlorobutanol, etc. can be cited.

[0042] In the preparation method provided by the present invention, in step a), a molecular weight regulator is preferably further added to the reaction system of the prepolymerization reaction. The molecular weight regulator includes, but is not limited to, vinyl compounds and / or diene compounds. Among them, as long as the vinyl compound is an organic compound having a vinyl group and not belonging to the diene compounds described below, there is no particular limitation. Examples thereof include α-olefins such as 1-butene, 1-pentene, 1-hexene, and 1-octene; styrenes such as styrene and vinyltoluene; ethers such as ethyl vinyl ether, isobutyl vinyl ether, and allyl glycidyl ether; halogen-containing vinyl compounds such as allyl chloride; oxygen-containing vinyl compounds such as allyl acetate, allyl alcohol, and glycidyl methacrylate; nitrogen-containing vinyl compounds such as acrylamide; and silicon-containing vinyl compounds such as vinyltrimethylsilane and vinyltrimethoxysilane. As the diene compound, examples thereof include non-conjugated dienes such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 2-methyl-1,4-pentadiene, and 2,5-dimethyl-1,5-hexadiene; and conjugated dienes such as 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. The molecular weight regulator can be used alone or in combination of two or more. Moreover, as the molecular weight regulator, α-olefins are preferred, and 1-hexene and / or 1-octene are more preferred.

[0043] In the preparation method provided by the present invention, in step a), as the solvent used, as long as it can dissolve or disperse the obtained prepolymer and is inactive to the prepolymerization reaction, there is no particular limitation. Specifically, examples thereof include aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; alicyclic hydrocarbon solvents such as cyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, ethylcyclohexane, diethylcyclohexane, decalin, bicycloheptane, tricyclodecane, hexahydroindene, cyclohexane, and cyclooctane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; halogenated aliphatic hydrocarbon solvents such as dichloromethane, chloroform, and 1,2-dichloroethane; halogenated aromatic hydrocarbon solvents such as chlorobenzene and dichlorobenzene; nitrogen-containing hydrocarbon solvents such as nitromethane, nitrobenzene, and acetonitrile; ether solvents such as diethyl ether and tetrahydrofuran; and aromatic ether solvents such as anisole and phenetole. The solvent can be used alone or in combination of two or more. Moreover, as the solvent, aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, alicyclic hydrocarbon solvents, ether solvents, or aromatic ether solvents are particularly preferred. Further preferred is one or more of toluene, cyclohexane, methylcyclohexane, or tetrahydrofuran.

[0044] In the preparation method provided by the present invention, in step a), in order to control the viscosity of the prepolymer within a certain range, the process conditions of the prepolymerization reaction need to be strictly controlled, such as the type of polymerization monomer, the concentration of the polymerization monomer, the concentration of the catalyst system, the prepolymerization reaction temperature, the prepolymerization reaction time, the prepolymerization reaction mode, etc. In the present invention, the temperature of the prepolymerization reaction is preferably 0 to 100 °C, specifically 0 °C, 5 °C, 10 °C, 15 °C, 20 °C, 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C or 100 °C; the pressure of the prepolymerization reaction is preferably 0.1 to 1 MPa, specifically 0.1 MPa, 0.2 MPa, 0.3 MPa, 0.4 MPa, 0.5 MPa, 0.6 MPa, 0.7 MPa, 0.8 MPa, 0.9 MPa or 1 MPa; the time of the prepolymerization reaction is preferably ≤200 min, specifically 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 120 min, 150 min or 200 min.

[0045] In the preparation method provided by the present invention, in step b), there are no particular limitations on the conditions of the polymerization reaction, and it can be appropriately set according to the desired physical properties of the finally prepared cycloolefin polymer. In the present invention, the amount of the polymerization monomer used in step b) preferably accounts for 70 to 99.5 wt% of the total amount of the polymerization monomers in steps a) and b), more preferably 99 wt%; a molecular weight regulator is preferably further added to the reaction system of the polymerization reaction, and the specific selection of the molecular weight regulator can refer to the reaction system of the prepolymerization reaction, which will not be elaborated here; the temperature of the polymerization reaction is preferably 25 to 150 °C, specifically 25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, 85 °C, 90 °C, 95 °C, 100 °C, 110 °C, 120 °C, 130 °C, 140 °C or 150 °C; the pressure of the polymerization reaction is preferably 0.1 to 5 MPa, specifically 0.1 MPa, 0.3 MPa, 0.5 MPa, 0.7 MPa, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa or 5 MPa; the time of the polymerization reaction is preferably 10 min to 10 h, specifically 10 min, 20 min, 30 min, 40 min, 50 min, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 6 h, 7 h, 8 h, 9 h or 10 h.

[0046] In the preparation method provided by the present invention, in step b), the hydrogenation reaction is a reaction in which all carbon-carbon double bonds and unsaturated bonds such as benzene rings existing in the main chain and / or side chain of the cycloolefin ring-opening polymer are completely hydrogenated; this hydrogenation reaction process is carried out by adding a hydrogenation catalyst to the polymerization reaction product in an inert solvent and supplying hydrogen to the reaction system.

[0047] In the preparation method provided by the present invention, in step b), the hydrogenation catalyst used in the hydrogenation reaction can be a homogeneous catalyst or a heterogeneous catalyst. Since the homogeneous catalyst is easily dispersed in the hydrogenation reaction solution, the addition amount of the catalyst can be suppressed. In addition, since the homogeneous catalyst has sufficient activity even without high temperature and high pressure, it is not easy to cause the decomposition and gelation of the cycloolefin ring-opening polymer and its hydride. Therefore, from the viewpoints of time cost and the quality of the product, it is preferable to use a homogeneous catalyst.

[0048] In the preparation method provided by the present invention, in step b), examples of the homogeneous catalyst used in the hydrogenation reaction include: Wilkinson coordination compound [tris(triphenylphosphine)rhodium(I)]; combinations such as cobalt acetate / triethylaluminum, nickel acetylacetonate / triisobutylaluminum, dichlorodicyclopentadienyltitanium / n-butylaluminum, dichlorodicyclopentadienylzirconium / sec-butyl lithium, tetrabutoxytitanate / dimethylmagnesium, etc., and catalysts formed by combinations of transition metal compounds and organometallic compounds.

[0049] In the preparation method provided by the present invention, in step b), examples of the heterogeneous catalyst used in the hydrogenation reaction include heterogeneous catalysts in which metals such as nickel (Ni), palladium (Pd), platinum (Pt), ruthenium (Ru), and rhodium (Rh) are supported on a carrier. Particularly when reducing the amount of impurities in the obtained hydride, as the carrier, adsorbents such as alumina, diatomaceous earth, and activated carbon are preferably used.

[0050] In the preparation method provided by the present invention, in step b), the inert solvent used in the hydrogenation reaction is not particularly limited as long as it is an organic solvent that has no activity in the hydrogenation reaction. From the viewpoint of easily dissolving the generated hydride, hydrocarbon solvents are usually used. Examples of the hydrocarbon solvents include: aromatic hydrocarbon solvents such as benzene, toluene, and xylene; aliphatic hydrocarbon solvents such as n-pentane, n-hexane, and n-heptane; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, decalin, and bicyclononane. These organic solvents can be used alone or in combination of two or more. In addition, the solvents usually used in the ring-opening polymerization reaction are also suitable as the solvents for the hydrogenation reaction. Therefore, after adding a hydrogenation catalyst to the ring-opening polymerization reaction solution, it can be supplied to the hydrogenation reaction.

[0051] In the preparation method provided by the present invention, in step b), the conditions of the hydrogenation reaction can be appropriately selected according to the type of hydrogenation catalyst used. Among them, the temperature of the hydrogenation reaction is usually -20 to +250 °C, preferably -10 to +220 °C, more preferably 0 to 200 °C, and specifically can be 170 °C; the hydrogen pressure of the hydrogenation reaction is usually 0.01 to 10.0 MPa, preferably 0.05 to 8.0 MPa, more preferably 0.1 to 5.0 MPa, and specifically can be 4.5 MPa; the time of the hydrogenation reaction is usually 0.1 to 50 h, and specifically can be 8 h.

[0052] In the preparation method provided by the present invention, in step b), after the polymerization reaction and the hydrogenation reaction, post-treatment is carried out as needed, whereby the target ring-opening polymer hydride (cycloolefin polymer) can be separated well. For example, after the hydrogenation reaction is terminated, catalyst residues can be removed by centrifugation, filtration and other treatments. In addition, adsorbents such as activated clay and alumina can also be added as needed.

[0053] The present invention also provides a cycloolefin polymer prepared by the preparation method according to the above technical solution. In the present invention, the cycloolefin polymer can specifically be one or more of norbornene homopolymers, norbornene copolymers and cycloolefin multi-block copolymers.

[0054] The present invention also provides an optical resin composition, characterized in that the optical resin composition contains the cycloolefin polymer according to the above technical solution.

[0055] In the optical resin composition provided by the present invention, other polymer materials and / or additives are also contained. It should be noted that as long as the polymer materials and additives can be sufficiently dispersed in the cycloolefin polymer, there are no particular limitations on the types of polymer materials and additives.

[0056] In the optical resin composition provided by the present invention, the polymer materials and additives can be added at any stage in the preparation of the cycloolefin polymer, can also be kneaded with the cycloolefin polymer using a kneader, or can be mixed with the cycloolefin polymer in a molding device.

[0057] The present invention also provides an optical resin product made of the optical resin composition according to the above technical solution. Moreover, since the optical material of the present invention is formed by the optical resin composition of the present invention, the tensile strength, tensile modulus and film thickness uniformity are more excellent. In addition, the method for manufacturing the molded body is not particularly limited, and known molding means such as injection molding, compression molding, extrusion molding, etc. can be used to form the resin composition into a molded body. The shape of the molded body can be appropriately selected according to the use.

[0058] In the optical resin product provided by the present invention, the optical resin product is preferably an optical lens, an optical film, an optical disc, a light guide plate or a display panel. Among them, the optical film is preferably used in a polarizing film.

[0059] In the optical resin product provided by the present invention, taking the optical film as an example, the elongation at break (ductility) of the optical resin product is preferably 15% or more; the tensile strength of the optical resin product is preferably 50 MPa or more, more preferably 55 MPa or more, and further preferably 60 MPa; the tensile modulus of the optical resin product is preferably 2000 MPa or more, more preferably 2100 MPa or more, and further preferably 2200 MPa; the film thickness uniformity (standard deviation value of the film thickness at a 15 mm interval measured by a continuous film thickness measuring instrument) of the optical resin product is preferably within 3 μm, more preferably within 2.5 μm, further preferably within 2.0 μm, and particularly preferably within 1.5 μm.

[0060] For the sake of clarity, the following will be described in detail through the following examples and comparative examples. Unless otherwise specified, the raw materials used in the following examples and comparative examples are commercially available products, and the various ratios and parts are by weight.

[0061] In the following examples and comparative examples of the present invention, the viscosity of the prepolymer and the elongation at break (ductility), tensile strength, tensile modulus, and thickness uniformity of the film material were measured and evaluated by the following methods:

[0062] (1) Prepolymer viscosity:

[0063] Using a rotational viscometer (manufactured by Shanghai Precision Instrument and Meter Co., Ltd., model SNB-1), the viscosity of the prepolymer sample was measured at 25°C.

[0064] (2) Properties of the film material:

[0065] Based on JIS K 7127, using a Tensilon universal testing machine (manufactured by ORIENTIC Co., product name "RTC-1125A"), at 23°C, tensile speed: 0.5 mm / min, distance between chucks: 100 mm, the tensile strength and tensile modulus (unit: MPa) at the breaking point of the test piece were measured, and the elongation at break was taken as the elongation at break (%).

[0066] Using a continuous film thickness measuring instrument K-306A and K-310C manufactured by AnritsuCo., the film thickness was measured every 15 mm, and the thickness change was calculated and determined; that is, the average thickness and standard deviation value of the film were measured using the above device, and the standard deviation value was used to evaluate the thickness uniformity of the film thickness.

[0067] Example 1

[0068] Into a polymerization reactor that has been dried and purged with nitrogen, add 7 parts (1% relative to the total amount of monomers used in the polymerization) of a monomer mixture composed of 70% methylene tetrahydrofluorene (MTF), 25% tetracyclododecene (TCD), and 5% norbornene (NB), 1600 parts of ultra-dry cyclohexane, 5 parts of 1-hexene, 0.3 part of isobutanol, 0.8 part of triisobutylaluminum, and 30 parts of a 0.5% cyclohexane solution of tungsten hexachloride. Stir at 55 °C for 10 minutes to obtain a prepolymer. The viscosity measurement results of the prepolymer are shown in Table 1.

[0069] Next, raise the temperature of the reaction system to 55 °C. While stirring, continuously dropwise add 693 parts of the above monomer mixture and 70 parts of a 0.6% cyclohexane solution of tungsten hexachloride into the above polymerization reactor over 120 minutes respectively. Then, stir for 30 minutes after the dropping is completed, and then add 1 part of isopropanol to terminate the polymerization reaction. The polymerization reaction solution is measured by a gas chromatograph, and the conversion rate of the monomer to the polymer is 100%.

[0070] Next, transfer 300 parts of the polymerization reaction solution containing the above polymer to an autoclave equipped with a stirrer. Add 1.2 parts by weight of a diatomaceous earth-supported nickel catalyst (manufactured by Zudochemy Catalyst; G-96D, nickel loading rate 58 wt%) and 200 parts by weight of cyclohexane to the hydrogenation reactor. The hydrogenation reaction is carried out at 170 °C and a hydrogen pressure of 4.5 MPa for 8 hours. The reaction solution after the reaction is pressure-filtered using diatomaceous earth as a filter aid through a pressure filter (manufactured by Ishikawajima Harima Heavy Industries, Ltd., leaf filter) at a pressure of 0.25 MPa to obtain a colorless and transparent solution.

[0071] Next, pour the above colorless and transparent solution into 3000 parts by weight of isopropanol under stirring to precipitate the hydride, and filter and collect the mixture. Then, wash with 500 parts by weight of acetone, and dry in a vacuum dryer under reduced pressure to 0.1 kPa or less at 100 °C for 24 hours to obtain a cycloolefin polymer.

[0072] Mix and extrude the above cycloolefin polymer and 0.3 part of an antioxidant using a twin-screw mixer to obtain a granulated resin composition.

[0073] Clamp the above resin composition with a SUS metal plate heated to 250 °C, apply a pressure of 100 kgf with a stamping machine for 3 minutes, and further apply a pressure of 100 kgf with a stamping machine set at 25 °C for 5 minutes to produce a film with a thickness of 100 μm, and then cut it into test pieces of 50 × 50 mm. The physical property measurement results of the film are shown in Table 1.

[0074] Example 2

[0075] In a polymerization reactor that has been dried and purged with nitrogen, 7 parts (1% relative to the total amount of monomers used in the polymerization) of a monomer mixture composed of 70% methylene tetrahydrofluorene (MTF), 25% tetracyclododecene (TCD), and 5% norbornene (NB), 1600 parts of ultra-dry cyclohexane, 0.8 part of ethoxydiethylaluminum, and 40 parts of a 2.0% toluene solution of tungsten phenylimide tetrachloride (tetrahydrofuran) were added. The mixture was stirred at 75 °C for 45 minutes to obtain a prepolymer. The viscosity of the prepolymer was measured, and the results are shown in Table 1.

[0076] Next, while maintaining the reaction system at 75 °C and stirring, 693 parts of the above monomer mixture and 4.5 parts of 1-hexene were continuously added dropwise to the above polymerization reactor over 120 minutes. Then, after the addition was completed, the mixture was stirred for 30 minutes, and then 1 part of isopropanol was added to terminate the polymerization reaction. The polymerization reaction solution was measured by gas chromatography, and the conversion rate of the monomer to the polymer was 100%.

[0077] Except for this, the procedure was the same as in Example 1 to obtain a cycloolefin polymer film. The physical properties of the film were measured, and the results are shown in Table 1.

[0078] Example 3

[0079] A prepolymer was obtained by mixing at 100 °C for 5 minutes. Except for this, the procedure was the same as in Example 1 to obtain a cycloolefin polymer film.

[0080] Example 4

[0081] A prepolymer was obtained by mixing at 30 °C for 90 minutes. Except for this, the procedure was the same as in Example 2 to obtain a cycloolefin polymer film.

[0082] Example 5

[0083] A prepolymer was obtained by mixing at 5 °C for 75 minutes. Except for this, the procedure was the same as in Example 1 to obtain a cycloolefin polymer film.

[0084] Example 6

[0085] A prepolymer was obtained by mixing at 40 °C for 200 minutes. Except for this, the procedure was the same as in Example 1 to obtain a cycloolefin polymer film.

[0086] Comparative Example 1

[0087] A prepolymer was obtained by mixing at -10 °C for 100 minutes. Except for this, the procedure was the same as in Example 1 to obtain a cycloolefin polymer film.

[0088] Comparative Example 2

[0089] The ultradry cyclohexane in Example 2 was replaced with ultradry tetrahydrofuran to obtain a prepolymer, and otherwise, the same procedure as in Example 2 was carried out to obtain a cycloolefin polymer film.

[0090] Comparative Example 3

[0091] First, 140 parts (20% relative to the total amount of monomers used in the polymerization) of the monomer mixture were added to obtain a prepolymer, and then the remaining 560 parts of the monomer compound were continuously added dropwise. Otherwise, the same procedure as in Example 1 was carried out to obtain a cycloolefin polymer film.

[0092] Table 1 Performance Test Results

[0093]

[0094] As can be seen from the data in Table 1, using the two-step polymerization process, when the viscosity of the prepolymer (at 25 °C) was controlled within the range of 3 - 300 cps, the ductility (elongation at break) of the cycloolefin polymers prepared in Examples 1 - 5 was greater than 15%, and the tensile strength was greater than 50 MPa, and the tensile modulus was greater than 2000 MPa; in the large-scale production process of optical films in the industry, the film thickness uniformity generally fluctuated within the range of 3 - 5 μm, while after improvement by this manufacturing method, the film thickness uniformity could be controlled within the range of 1 - 3 μm. In addition, as in Example 6, when the mixing time was extended to 200 min (greater than 100 min), the viscosity of the obtained prepolymer was 176.4, which was within the process control range of 3 - 300 cps, and a cycloolefin polymer with excellent ductility (elongation at break greater than 15%), high tensile strength (greater than 50 MPa), high tensile modulus (greater than 2000 MPa), and high film thickness uniformity (less than 3 μm), as well as a molded article formed using this resin composition, could also be prepared.

[0095] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A method for preparing a cycloolefin polymer, characterized in that: The following steps are involved: a) in the presence of a catalyst system, the polymerization monomer is subjected to a prepolymerization reaction in a solvent to obtain a prepolymer; The polymerization monomer comprises norbornene-based cycloolefin, and the viscosity of the prepolymer at 25° C. is 3 to 300 cps; b) The prepolymer is further mixed with a polymerizable monomer to undergo a polymerization reaction, and then the polymerization product is subjected to a hydrogenation reaction to obtain a cycloolefin polymer.

2. The preparation method according to claim 1, characterized in that: The temperature of the prepolymerization reaction is 0-100°C.

3. The preparation method according to claim 1, characterized in that: The prepolymerization reaction time is ≤200 min.

4. The preparation method according to claim 1, characterized in that: The catalyst system is a homogeneous or heterogeneous catalyst system that can catalyze the polymerization monomer to undergo a ring-opening polymerization reaction.

5. The preparation method according to claim 1, characterized in that: A molecular weight regulator is also added to the reaction system of the prepolymerization reaction and / or polymerization reaction; the molecular weight regulator includes a non-diene vinyl compound and / or a diene compound, and the non-diene vinyl compound is an organic compound having a vinyl group and not belonging to a diene compound.

6. The preparation method according to claim 1, characterized in that: In step a), the solvent comprises one or more of toluene, cyclohexane, methylcyclohexane and tetrahydrofuran.

7. The preparation method according to claim 1, characterized in that: In step a), the polymerization monomer comprises a norbornene-based cycloolefin having a structure represented by formula (I); In formula (I), n is 0 or 1, m is an integer of 0 or greater, R1, R2, R3 and R4 each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted C1 to C2 having a linking group containing oxygen, nitrogen, sulfur or silicon; 30 A hydrocarbon group or a polar group having a connecting group containing oxygen, nitrogen, sulfur or silicon.

8. The preparation method according to claim 7, characterized in that: In formula (I), R1 and R2, R3 and R4, or R2 and R3 are bonded to each other to form a carbocyclic ring or a heterocyclic ring; The carbocyclic ring or heterocyclic ring is a monocyclic structure, or is fused with other rings to form a polycyclic structure; The carbocyclic ring or heterocyclic ring is an aromatic ring or a non-aromatic ring.

9. A cycloolefin polymer, characterized in that Prepared according to the preparation method according to any one of claims 1 to 8.

10. An optical resin composition, characterized in that: The optical resin composition contains the cycloolefin polymer according to claim 9.

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