JPH0717713B2 - Poly (meth) acrylate polymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel poly (meth) acrylate-based polymer. More specifically, it has excellent light scattering properties, excellent transparency, low water absorption and excellent water resistance, and excellent mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance and rigidity. A poly (meth) acrylate-based polymer is provided.

[Conventional technology]

Conventionally, in applications such as optical fibers, optical disks, optical cards, plastic lenses, and optical materials such as transparent conductive sheets, poly (meth) acrylate-based polymers, polycarbonate-based polymers, polystyrene-based polymers, epoxy resins, etc. Has been proposed, and poly (meth) acrylate-based polymers such as polymethylmethacrylate and polycarbonate-based polymers have already been actually used for these applications. However, among the conventionally known poly (meth) acrylate-based polymers, polymethyl acrylate is inferior in heat resistance and heat stability, inferior in performance such as chemical resistance and solvent resistance, and has high water absorption and water resistance. Since it is inferior in properties, it has a drawback that it cannot be used in the fields requiring these performances. Further, there is a drawback that even polymethylmethacrylate cannot be used especially in the fields where heat resistance and heat stability are required. In the field of this optical material, JP-A-58-221808 and JP-A-59-136704 attempt to solve the above-mentioned drawbacks of poly (meth) acrylate-based polymers known in the art.
JP-A-59-162503, JP-A-59-172603, JP-A-59-176703, JP-A-59-200202, JP-A-59-214802, JP-A-60- No. 124605 and JP-A No. 60-144313 disclose homopolymers of polycyclic alicyclic alkyl (meth) acrylates, or polycyclic alicyclic alkyl (meth) acrylates and various (meth) acrylates. A method using a copolymer of a system monomer has been proposed. The homopolymers or copolymers of polycyclic alicyclic alkyl (meth) acrylates disclosed in any of these publications are more heat-resistant than polymethyl (meth) acrylates that have been conventionally used. Although the heat resistance stability is improved, the degree of improvement is small, the practical performance is not sufficient, and the polymer having excellent heat resistance and heat stability, small light scattering property and excellent transparency is an optical material. There is a strong demand in the field of.

[Problems to be solved by the invention]

The present inventors have found that the poly (meth) acrylate-based polymer in the use of optical materials such as optical fibers, optical disks (write-once, rewritable), optical cards, plastic lenses, and transparent conductive sheets is in the above-mentioned situation. Recognize, light scattering and small transparency, small water absorption and excellent water resistance,
Moreover, research and development has been conducted on poly (meth) acrylate polymers having excellent mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance and rigidity. As a result, the present inventors have found that a poly (meth) acrylate-based polymer composed of a specific polycyclic (meth) acrylate-based monomer achieves this object, and arrived at the present invention. Therefore, the object of the present invention is to have excellent light scattering and excellent transparency, low water absorption and excellent water resistance, and further to mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance and rigidity. It is to provide an excellent novel poly (meth) acrylate-based polymer.

[Means for Solving Problems] and [Operation] According to the present invention, the general formula [I] [In the formula, n is an integer of 1 to 3, X ¹ and X ² are both a direct bond or a lower alkylene group optionally having an oxygen atom, R is a hydrogen atom or a methyl group, R ¹ to R ¹⁰ are hydrogen atoms or lower alkyl groups] and are derived from a polycyclic (meth) acrylate monomer represented by the following formula [Ia] [Wherein, n, X ¹ , X ² , R and R ¹ to R ¹⁰ are the same as those in the above formula [I]], which is a polymer comprising a repeating unit and is in toluene at 30 ° C. A poly (meth) acrylate system characterized by an intrinsic viscosity [η] measured in the range of 0.002 to 20 dl / g and a glass transition point measured by a differential scanning calorimeter in the range of 80 to 200 ° C. A polymer is provided as the material invention.

The polycyclic (meth) acrylate monomer constituting the poly (meth) acrylate-based polymer of the present invention has the general formula [I] [In the formula, n is an integer of 1 to 3, X ¹ and X ² are both a direct bond or a lower alkylene group optionally having an oxygen atom, R is a hydrogen atom or a methyl group, R ¹ to R ¹⁰ are a hydrogen atom or a lower alkyl group].

In the general formula [I], as X ¹ and X ² , a direct bond or a lower alkylene group such as a methylene group, an ethylene group, a propylene group, a butylene group, an oxygen-containing lower alkylene group such as an oxyethylene group, an oxypropylene group, etc. R ¹ to R ¹⁰ may be a hydrogen atom or a lower alkyl group such as a methyl group, an ethyl group, a propyl group and a butyl group, which may be different from each other. May be different, or all may be the same.

The polycyclic (meth) acrylate monomer has, for example, a corresponding general formula [II] [Wherein, n and R ¹ to R ¹⁰ are the same as the above], the polycyclic olefin represented by the formula is reacted with formic acid or the resulting polycyclic alcohol is converted to ethylene oxide, propylene oxide, or the like. By reacting an alkylene oxide, the following general formula [III] [Wherein ^{one of} X ₀ ¹ and X ₀ ² is a hydroxyl group, the other is a hydrogen atom, and n, X ¹ , X ² and R ¹ to R ¹⁰ are all the same as defined above] And a (meth) acrylic acid such as acrylic acid or methacrylic acid or a (meth) acrylic acid halide such as acrylic acid halide or methacrylic acid halide is reacted with the polycyclic alcohol. Can be prepared by

Among the polycyclic (meth) acrylate monomers, the compounds represented by Table 1 can be specifically exemplified as the monomer represented by the general formula [I].

The intrinsic viscosity [η] of the poly (meth) acrylate polymer of the present invention measured in toluene at 30 ° C. is 0.002 to 20 dl /
g, preferably 0.05 to 10 dl / g, more preferably 0.2
To 5 dl / g, and the glass transition point measured by a differential deterministic calorimeter is 80 to 200 ° C., preferably 105.
It is a polymer characterized by being in the range of 200 to 200 ° C.

The molecular weight distribution (w / n) of the poly (meth) acrylate polymer measured by gel permeation chromatography is usually 10 or less, preferably 1.0 to 3
The crystallinity measured by X-ray diffraction is usually 5% or less, preferably 1% or less, and the density is usually 1.00 to 1.40 g / cm ³ , preferably 1.05 to 1.30 g.
/ cm ^{3 in} the range, the softening point measured by a thermal mechanical analyzer (TMA) (manufactured by Dupont) is usually 100 to 220 ° C, preferably 120 to 220 ° C.
Refractive index measured by D-line at 250 ℃ with Atsube refractometer is usually 1.4
It is in the range of 0 to 1.75, preferably 1.45 to 1.65, and the haze measured by a Haze meter according to ASTM D 1003-52 is usually 20% or less, preferably 5% or less.

The poly (meth) acrylate polymer has a substantially linear structure. This can also be confirmed by the fact that the poly (meth) acrylate polymer is dissolved in an organic solvent, for example, toluene at 30 ° C. when measuring the intrinsic viscosity [η].

As the method for producing the poly (meth) acrylate-based polymer of the present invention, any of the suspension polymerization, emulsion polymerization, solution polymerization and bulk polymerization used for the production of polymethylmethacrylate can be used. In order to obtain a highly pure polymer, bulk polymerization is preferable.

In bulk polymerization method usually 60 ℃ ~ 250 ℃, preferably, a method of polymerizing at a temperature of 150 ℃ ~ 230 ℃,
Alternatively, it is possible to exemplify a method in which the reaction temperature is raised from 60 ° C. along with the progress of polymerization and the reaction is almost completed at 180 ° C. to 230 ° C.

As the radical polymerization initiator, for example, di-t-butyl peroxide, dicumyl peroxide, methyl ethyl ketone peroxide, t-butyl perphthalate, t-
Organic peroxides such as butyl perbenzoate, di-t-butyl peracetate and t-butyl perisobutyrate, and azo compounds such as 1,1'-azobiscyclohexanecarbonitrile and 2-cyano-2-propylazoformamide Is mentioned.

In the polymerization system, t-butyl mercaptan, n-butylmethyl mercaptan, and n-butylmercaptan are used for the purpose of controlling the molecular weight.
A chain transfer agent such as octyl mercaptan or n-dodecyl mercaptan may be added in an amount of about 1 mol% or less based on the monomers.

Further, a photopolymerization method using ultraviolet rays or the like can also be adopted.

The poly (meth) acrylate polymer of the present invention derived from the polycyclic (meth) acrylate monomer as described above is
It has the following repeating unit [Ia].

[In the formula, n, X ¹ , X ² , R and R ¹ to R ¹⁰ are the same as those in the above formula [I]] The poly (meth) acrylate polymer of the present invention has extremely small light scattering property and transparency. It has excellent mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance, dielectric properties and rigidity, so it is extremely suitable for use as an optical material, especially a light transmissive optical material. can do. When the poly (meth) acrylate-based copolymer of the present invention is used for a light-transmitting optical material, it has the following characteristics.

Since it has excellent dimensional accuracy, it is a product that meets the intended size, and there is no distortion of optical characteristics due to distortion, and it has excellent heat resistance, so it can be used at or near high temperature parts, and it has chemical resistance and solvent resistance. Since it has excellent properties, it is easy to handle, and because it is thermoplastic, the usual plastics melt molding method can be applied.

For example, when it is used as a substrate for optical discs, it provides a substrate for discs that solves the problems of heat resistance of conventional polymethylmethacrylates, birefringence of polycarbonates, and dimensional stability all at once. Therefore, the disc substrate of the present invention on which a recording layer is laminated by various known methods can be used as a compact disc, a video disc, a write-once optical disc, a rewritable optical disc, and a magneto-optical disc. It can also be used as an optical card using a similar recording method.

More specifically, the optical disc of the present invention will be described.
The substrate obtained by injection-molding the above-mentioned polymer into a mold set with a stamper having irregularities corresponding to information bits, a material with high reflectance, such as Ni, Al, Au, etc., coated, laser A read-only disc for reading out information by utilizing light reflection, or a head used for scanning in contact with a groove and an information bit provided in the groove lower part using a groove as an ordinary recording plate as an information recording layer. There is a read-only disc for reading out information by utilizing a change in electrostatic capacity between and, and an optical disc provided with a recording layer that changes by light.
As the light-change recording layer, as in the case of As-Te-Ge system, the one that uses the change of light reflectance and light transmittance caused by the amorphous-crystal phase change by laser light irradiation, and the same phase change is used. Teox (0 <X <2) or GdCo, TbFe, GdTb
Those that use magnetization reversal, such as Fe, TbCo, and TbDyFe, and organic dyes can also be used.

Further, for example, a polymer as a core layer or a cladding layer,
A combination of various known optical fiber materials and optical fibers,
It may be used as an optical fiber connector or an arrayed optical fiber. Especially when it is used as a cladding layer, it is excellent in heat resistance, chemical resistance and solvent resistance, so that the core layer is sufficiently protected and it can be used in a high temperature portion which cannot be reached by the conventional polymethylmethacrylate type. Other plastics that form a core layer or a cladding layer when forming an optical fiber include polymethylmethacrylate and its derivatives, fluorine-based polymers, poly-4-methylpentene-1 and its copolymers, and polyarylene. Additives may be added to improve the properties, these may be modified, or modified products may be added.

Another example of use is a plastic lens. Various shapes such as spherical lenses and flat lenses can be considered. This lens is used not only for spectacles, but also in various fields such as a spectacle, a magnifying glass, a Fresnel lens used for lights or lamps of automobiles and bicycles.

It may also be used as an optical material for optoelectronics such as an optical demultiplexer, an optical waveguide, an OEI substrate, and an optical filter. Furthermore, building window glass, bicycle glass,
It can be used for railways, airplanes, window glass of ships and other fields.

〔Example〕

 The contents of the present invention will be described in detail below with reference to preferred examples.

Example 1 Acrylic acid-3-tetracyclo [4,4,0,1 ^2,5 , 1 ^7,10 ] dodecyl 99 parts, n-octyl mercaptan 0.05 part, 2,2'-azo purified by vacuum distillation A monomer mixture consisting of 0.05 part of bisisobutyronitrile was mixed in the absence of oxygen and polymerized at 80 ° C. for 24 hours. 220 to measure physical properties
1 mm and 2 mm thick press-formed sheets were prepared by hot pressing at ℃. The obtained polymer had an intrinsic viscosity [η] of 0.58 determined in a toluene solution at 30 ° C., a softening point measured by TMA (manufactured by Dupon) of 138 ° C., and a refractive index n ^D by an Atsube refractometer of 1.532. When X-ray diffraction was performed using this sheet, scattering by crystals was not observed and the crystallinity was 0%.
The transparency was 2.5% when the haze was measured with a haze meter based on ASTM D 1003-52. Also, ASTM D
Compliant flexural rigidity ^{790 (FM: kg / cm 2} ) was found to be 36000kg / cm ^2.

Examples 2 to 6 Monomers were changed in the same manner as in Example 1 to obtain polymers. Their physical properties are collectively shown in Table 3.

Claims (1)

[Claims] 1. A general formula [I] [In the formula, n is an integer of 1 to 3, X ¹ and X ² are both a direct bond or a lower alkylene group optionally having an oxygen atom, R is a hydrogen atom or a methyl group, R ¹ to R ¹⁰ are hydrogen atoms or lower alkyl groups] and are derived from a polycyclic (meth) acrylate monomer represented by the following formula [Ia] [Wherein, n, X ¹ , X ² , R and R ¹ to R ¹⁰ are the same as those in the above formula [I]], which is a polymer comprising a repeating unit and is in toluene at 30 ° C. A poly (meth) acrylate system characterized by an intrinsic viscosity [η] measured in the range of 0.002 to 20 dl / g and a glass transition point measured by a differential scanning calorimeter in the range of 80 to 200 ° C. Polymer.