JPH0717718B2 - Poly (meth) acrylate copolymer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel poly (meth) acrylate-based copolymer. Furthermore, it has extremely low light scattering, excellent transparency, low water absorption and excellent water resistance, and also has excellent mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance, dielectric properties and rigidity. And a poly (meth) acrylate-based copolymer.

[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 properties, particularly heat resistance and heat stability.
Further, even polymethylmethacrylate has a drawback that it cannot be used especially in the fields where heat resistance and heat stability are required.

In order to improve the above-mentioned drawbacks of conventionally known poly (meth) acrylate polymers in the field of optical materials, JP-A-58-221808 and JP-A-59-136704 are disclosed. JP-A-59-162503, JP-A-59-172603, JP-A-59-176703, JP-A-59-176703
59-200202, JP 59-214802, JP 60
-1246050 and JP-A-60-144313, a homopolymer of a polycyclic alicyclic alkyl (meth) acrylate or a polycyclic alicyclic alkyl (meth) acrylate and various (meth) A method using a copolymer of an acrylate-based 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, we have researched and developed a poly (meth) acrylate-based copolymer 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 copolymerization polymer comprising a specific polycyclic (meth) acrylate-based monomer component (a) and another (meth) acrylate-based monomer (b). We have found that coalescence achieves this goal 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 copolymer.

[Means for Solving Problems] and [Operation] According to the present invention, (a) 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 [I a] [Wherein n, X ¹ , X ² , R and R ¹ to R ¹⁰ are the same as those in the above formula [I]] and the repeating unit component is 5
To 99 mol%, and (b) the general formula [II] [Wherein R ²⁰ represents a hydrogen atom or a methyl group, and R ²¹ represents a hydrocarbon group having 1 to 10 carbon atoms] and is derived from a (meth) acrylate monomer represented by the following formula: II a] [Wherein R ²⁰ and R ²¹ are the same as above], the repeating unit component is in the range of 1 to 95 mol%, and is a poly (meth) acrylate copolymer having a random sequence, The intrinsic viscosity [η] measured in toluene at 30 ° C is in the range of 0.002 to 20 dl / g, and the glass transition point measured by a differential scanning calorimeter is 10 to 200.
A poly (meth) acrylate-based copolymer characterized by being in the range of ° C is provided as a material invention.

The polycyclic (meth) acrylate monomer constituting the poly (meth) acrylate-based copolymer 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 or a butylene group, an oxygen-containing lower alkylene group such as an oxyethylene group or an oxypropylene group, etc. Examples of R ¹ to R ¹⁰ include 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 [III] [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 [IV] [In the formula, one of X ₀ ¹ and X ₀ ² is a hydroxyl group,
The other is a hydrogen atom, n, X ¹ , X ² and R ¹ to R ¹⁰
Are the same as above] to obtain a polycyclic alcohol represented by
It can be prepared by reacting (meth) acrylic acid such as methacrylic acid or (meth) acrylic acid halide such as acrylic acid halide or methacrylic acid halide.

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 (meth) acrylate monomer component (b) constituting the poly (meth) acrylate-based copolymer of the present invention has the general formula [II] [In the formula, R ²⁰ represents a hydrogen atom or a methyl group, and R ²¹ represents a hydrocarbon group having 1 to 10 carbon atoms], which is a (meth) acrylate monomer component. The (meta)
Specific examples of the acrylate monomer component (b) include methyl ((meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, pentyl ( Examples include (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, cyclohexyl (meth) acrylate, and benzyl (meth) acrylate. You can

In the poly (meth) acrylate-based copolymer of the present invention, the repeating unit component (a) derived from the polycyclic (meth) acrylate represented by the formula [I] and represented by the following formula [Ia]
Content of 5 to 99 mol%, preferably 10 to 99 mol%, more preferably 30 to 90 mol%, [In the formula, n, X ¹ , X ² R and R ¹ to R ¹⁰ are represented by the above formula [I].
And is derived from the (meth) acrylate represented by the formula [II],
The content of the repeating unit component (b) represented by the following formula [II a] is 1 to 95 mol%, preferably 1 to 90 mol%.
Is the range.

[In the formula, R ²⁰ and R ²¹ are the same as above] When the content of the (meth) acrylate component is more than 95 mol%, the heat resistance and heat stability of the poly (meth) acrylate copolymer are improved. The effect becomes smaller.

The intrinsic viscosity [η] of the poly (meth) acrylate-based copolymer of the present invention measured in toluene at 30 ° C. is 0.002 to 20 d.
l / g, preferably 0.05 to 10 dl / g, more preferably
It is in the range of 0.2 to 5 dl / g and has a glass transition point of 10 to 200 ° C. measured by a differential scanning calorimeter, preferably 5
It is a polymer characterized by being in the range of 0 to 200 ° C, more preferably 105 to 200 ° C.

The molecular weight distribution (w / n) of the poly (meth) acrylate-based copolymer measured by gel permeation chromatography is usually 10 or less, preferably 1.0 to 1.0.
It is in the range of 3.0, 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 1.3.
It is in the range of 0 g / cm ³ , and the softening point measured by a thermal mechanical analyzer (TMA) (manufactured by Dupont) is usually 20.
To 220 ° C., preferably 70 to 220 ° C., more preferably 120 to 220 ° C.
The refractive index (▲ n ²⁵ _D ▼) measured by D line at ℃ is usually in the range of 1.40 to 1.75, preferably 1.45 to 1.65.
Haze measured with a Haze meter according to TM D 1003-52 (Haz
e) is usually 20% or less, preferably 5% or less.

The poly (meth) acrylate-based copolymer has a substantially linear structure in which the polycyclic (meth) acrylate monomer component (a) and the (meth) acrylate monomer component (b) are randomly arranged and bonded. It has a shape-like structure. Having a substantially linear structure also means that the poly (meth) acrylate-based copolymer dissolves in an organic solvent, for example, toluene at 30 ° C. when measuring the intrinsic viscosity [η]. You can check.

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

In the bulk polymerization method, usually 60 ° C to 250 ° C, preferably 1
Examples thereof include a method of polymerizing at a temperature of 50 ° C to 230 ° C, or a method of raising the reaction temperature from, for example, 60 ° C as the polymerization proceeds to complete the reaction 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-butyl perbenzoate,
Examples thereof include organic peroxides such as di-t-butyl peracetate and t-butyl perisobutyrate, and azo compounds such as 1,1′-azobiscyclohexanecarbonitrile and 2-cyano-2-propylazoformamide.

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.

It is also possible to polymerize by photopolymerization with ultraviolet rays or the like.

The poly (meth) acrylate-based copolymer of the present invention has an extremely small light scattering property and excellent transparency, and further has excellent mechanical properties such as heat resistance, heat stability, chemical resistance, solvent resistance, dielectric properties and rigidity. Since it is excellent, it can be used very suitably as an optical material, particularly a light-transmissive optical material. When the poly (meth) acrylate-based copolymer of the present invention is used as a material 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 temperatures, and it is resistant to chemicals and solvents. 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 recording 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 above polymer obtained by injection molding in a mold set with a stamper having irregularities corresponding to the information bit, a substrate with high reflectance, for example, 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 type recording layer, as in the case of As-Te-Ge system, the one that uses the change of light reflectance and light transmittance due to the phase change of amorphous-crystal due to the laser irradiation, and the same phase change is used. TeOx (0 <X <2) or GdCo, TbFe, Gd
Those using magnetization reversal like TbFe, TbCo, TbDyFe,
Alternatively, an organic dye or the like can 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 graded 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 optical demultiplexers, optical waveguides, OEIC substrates, and optical filters. Furthermore, building window glass, bicycle glass,
It can be used for railroad or airplane, window glass of ships and other fields.

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

Example 1 under reduced pressure by distillation connexion purified acrylic acid-3-tetracyclo [4,4,0,1 ^2,5, 1 ^7,10] dodecyl 90 molar parts, 10 moles of methyl methacrylate, n- octyl mercaptan 0.05
A monomer mixture consisting of 0.05 part by mole of 2,2'-azobisisoptyronitrile was mixed at 70 ° C.
The polymerization was completed in 24 hours. 220 ℃ for measuring physical properties
1mm and 2mm thick press-formed sheets were made by the hot press. The obtained polymer had an intrinsic viscosity [η] of 0.50 determined in a toluene solution at 30 ° C., a softening point measured by TMA (manufactured by Dupon) of 135 ° C., and a refractive index n ^D by an Atsube refractometer of 1.522. When X-ray diffraction was carried out using this sheet, no crystal scattering was observed and the crystallinity was 0%. The transparency was 1.8% when measured with a Haze meter according to ASTM D 1003-52. The flexural rigidity (FM: kg / cm ² ) according to ASTM D 790 was 34,000 kg / cm ² .

Examples 2 to 6 Monomers In the same manner as in Example 1, the monomers were changed to obtain polymers. The physical properties thereof are summarized 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 [I a] [Wherein n, X ¹ , X ² , R and R ¹ to R ¹⁰ are the same as those in the above formula [I]] and the repeating unit component is 5
To 99 mol%, and (b) the general formula [II] [Wherein R ²⁰ represents a hydrogen atom or a methyl group, and R ²¹ represents a hydrocarbon group having 1 to 10 carbon atoms] and is derived from a (meth) acrylate monomer represented by the following formula: II a] [Wherein R ²⁰ and R ²¹ are the same as above], the repeating unit component is in the range of 1 to 95 mol%, and is a poly (meth) acrylate copolymer having a random sequence, The intrinsic viscosity [η] measured in toluene at 30 ° C is in the range of 0.002 to 20 dl / g, and the glass transition point measured by a differential scanning calorimeter is 10 to 200.
A poly (meth) acrylate-based copolymer characterized by being in the range of ° C.