WO2004070435A1

WO2004070435A1 - Heat-resistant optical material and medium for optical transmission therefrom

Info

Publication number: WO2004070435A1
Application number: PCT/JP2004/000691
Authority: WO
Inventors: Yoshito Tanaka; Takayuki Araki
Original assignee: Daikin Industries, Ltd.
Priority date: 2003-02-03
Filing date: 2004-01-27
Publication date: 2004-08-19
Also published as: JP2006188544A

Abstract

An optical material comprised of a polymer of 115°C or higher heat deformation temperature having alicyclic hydrocarbon moieties as side chains, which optical material has not only heat resistance but also signal transmission capability so as to enable use as a core material of optical transmission mediums, particularly a plastic optical fiber and a waveguide element.

Description

Akira Itoda Heat-resistant optical materials and optical transmission media using them

The present invention relates to an optical material having excellent heat resistance in addition to optical characteristics. The optical material of the present invention is suitable, for example, as an optical transmission medium, more specifically, as a material for a plastic optical fiber or a waveguide element, particularly as a core material. Background art

Conventionally, acryl resins, polycarbonates, amorphous polyolefins, and the like have been used as plastic optical materials.

Acrylic resins, especially polymethyl methacrylate (PMMA), are transparent to light in the visible region. For example, they are commonly used in the core of plastic optical fibers for communications using LEDs as a light source (wavelength: 65 nm). Has been. However, PMMA has insufficient heat resistance (Tg: 105 ° C), so it may change its shape or impair its properties in applications or places where heat resistance is required. It can only be used in environments up to about 70.

Attempts to improve the heat resistance of PMMA include a method of copolymerizing α-methylstyrene and a method of copolymerizing maleic anhydride / styrene. In this case, the heat resistance is improved, but the mechanical strength is accordingly reduced, so that the fiber is easily broken when bent after being formed.

Further, in order to improve the heat resistance, a method of copolymerizing α-fluoroacrylic acid esters (JP-A-63-33405) has been attempted. However, the heat resistance of the heat-resistant optical material aimed at by the present invention, particularly, the heat resistance required for a plastic optical fiber for an automobile is insufficient. In addition, methacrylic resins in which cyclohexyl methacrylate or phenyl methacrylate is copolymerized with methyl methacrylate have also been synthesized (Japanese Patent Application Laid-Open No. 59-15818, Cyclohexyl methacrylate and phenyl methacrylate were introduced for the purpose of improving the hygroscopicity of PMMA, and the heat resistance of the present invention was improved. It is insufficient from the requirements of heat resistance required for optical materials, especially plastic optical fibers for automobiles.

On the other hand, polycarbonate resin is excellent in heat resistance (Tg: 145.C), but when this is used for the core material of one optical fiber, the optical transmission loss is extremely large, Transmission, for example, transmission over 20 m is problematic.

Amorphous polyolefins (T g: 171 ° C, refractive index: 1.5 1) have particularly high heat resistance, but when exposed to air at high temperatures, coloring and gelling due to the effect of oxygen molecules may occur. It is easy to proceed, and as a result, when used as a core material of an optical fiber, there is a problem that transmission loss of an optical signal increases.

In recent years, various types of sensors, signal processing devices, lighting, and the like have been used for communication between inside and outside of a vehicle, aiming at upgrading, automation, and ensuring safety. As a result, the amount of signal processing has increased, and the resulting increase in the size of the electric cables has caused a problem of hindering the weight reduction of the vehicle body.

In order to solve such problems, it is desired to use an optical fiber that can realize multiplexing and high-speed communication instead of the electric cable.

However, the LAN communication cables for these vehicles (for in-vehicle LANs) are required to have heat resistance in high-temperature areas such as the engine room and ceiling. In some cases, a plastic optical fiber for automobiles that has both heat resistance and signal transmission capability is required, but such an optical fiber has not yet been obtained for the aforementioned reasons. You.

An object of the present invention is to provide an optical material having both heat resistance and signal transmission ability in view of the above-mentioned conventional technology.

Another object of the present invention is to obtain an optical transmission medium, more specifically, an optical material having a signal transmission capability that can be used as a core material of a plastic optical fiber or a waveguide element.

In particular, to obtain a plastic optical fiber using optical materials that can be used in the environment of 125 required in the engine room of a car or in the environment of 150 required in the engine room of a diesel car It is in. Disclosure of the invention

Means for Solving the Problems The present inventors have conducted intensive studies to solve the above problems, and found that a specific polymer having an alicyclic hydrocarbon moiety in the side chain is excellent in heat resistance. Among polymers having hydrocarbon moieties, polymers having a heat distortion temperature of a specific temperature or higher are useful as heat-resistant optical materials.For example, optical polymers used in plastic optical fibers for automotive LAN as described above They have found that they are useful as materials and have completed the present invention.

That is, the heat-resistant optical material of the present invention is a heat-resistant optical material comprising a polymer having an alicyclic hydrocarbon moiety in a side chain, and a polymer having an alicyclic hydrocarbon moiety in the side chain. The heat distortion temperature is 1 15 or more, and the equation (M 1)

-[M l] one [A] ― (M-1)

[Where,

The structural unit Ml has the formula (1): X

I

C H 2 ~ C

I (1)

c-o-z

o

(Wherein, X is at least one selected from the group consisting of H, CH ₃ , F, C 1 and CF ₃ ; Z is a monovalent organic group having 3 to 30 carbon atoms and having an alicyclic hydrocarbon moiety) Structural unit derived from at least one of the monomers represented by the formula, structural unit A is a structural unit derived from at least one of the monomers copolymerizable with the monomer of the formula (1)], It consists of a polymer containing 1 to 100 mol% of the structural unit Ml and 0 to 99 mol% of the structural unit A.

The polymer of the formula (M-1) according to the present invention comprises, as an essential component, a structural unit (Ml) derived from an acryl-based monomer of the formula (1) having an alicyclic hydrocarbon moiety in a side chain. It is a polymer, and it is preferable as a heat-resistant optical material because it is transparent to light in the visible region and has a high glass transition temperature by introducing an alicyclic hydrocarbon into a side chain.

Further, the above-mentioned polymer has a heat distortion temperature of 115 ° C or higher, and is an optical material usable even in a high-temperature environment of 70 or higher, for example, a material useful for a plastic optical fiber for a vehicle-mounted LAN. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic cross-sectional view of a main part structure of an optical waveguide device.

BEST MODE FOR CARRYING OUT THE INVENTION

The structural unit M 1 which is an essential component in the polymer of the formula (M-1) of the present invention has a general formula (M_2):

One [Ml-1]-[Ml -2] One (M-2) [Where,

Structural unit M 1-1 is represented by formula (2):

CH ₂ = CF

I

COZ ¹ (2)

II

0

(Wherein, Z ¹ is a monovalent organic group having 330 carbon atoms having an alicyclic hydrocarbon moiety), a structural unit derived from at least one monomer represented by the formula:

Structural unit Ml—2 is the formula (3):

X ³

I

Then l

I (3)

coz ²

II

o

(Wherein X ³ is at least one member selected from the group consisting of H CH ₃ C 1 and CF ₃ ; Z ² is a monovalent organic group having 330 carbon atoms having an alicyclic hydrocarbon moiety) Structural unit derived from at least one of the monomers represented by the following formulas], and may be a structural unit containing 199 mol% of the structural unit M1-1 and 199 mol% of the structural unit M1_2. preferable.

The first of the preferable polymers of the present invention is that the above-mentioned M1-1 power is 199 mol%, the structural unit Ml-2 is 199 mol%, and the arbitrary structural unit A in the formula (M-1) is 098 mol% % Polymer.

That is, α-fluoroacrylic acid-derived structural unit ァ 1-1 having an aliphatic alicyclic hydrocarbon moiety in the side chain and α-fluoroacrylic acid represented by the formula (2) among the monomers of the formula (1) It is a polymer that has structural unit Μ 1-2 as an essential component derived from a monomer other than a single unit. By introducing structural unit Ml-1, heat resistance and mechanical strength, especially bending strength, and even more It can give flexibility.

In addition, heat resistance and transparency can be imparted by introducing the structural unit Ml-2, In addition, it is possible to adjust the refractive index (for example, to set PMMA or higher by increasing the refractive index).

It is particularly preferable that the structural unit Ml-2 is a structural unit derived from methacrylate in which X ^{3 in the} formula (3) is CH ₃ , and the above-mentioned heat resistance, transparency and refractive index adjustment functions can be more effectively achieved. Can be granted.

The abundance ratio of the structural units M1-1 and M1-2 may be 1-99 mol% of Ml-1 and 1-99 mol% of the structural unit M1-2, but Ml-1 + When M1 -2 = 100 mol%, the ratio of Ml-1 / M1-2 is preferably 10/90 to 955 mol%, more preferably 25/75 to 90ZlO%, particularly preferably 40Z60. 9090Z10 mol% ratio, more preferably 4555-9010 mol% ratio.

In the polymer of the present invention of the formula (M-1) and the polymer containing the structural unit of the formula (M-2), the structural unit A as an optional component is represented by the formula (M-3):

-[A-1] one [A-2]-(M-3)

[Where,

Structural unit A_1 is represented by formula (4):

X ¹

I (4)

COR ¹

II

ο

(Wherein, X ¹ is at least one selected from the group consisting of H, CH ₃ , F, C 1 and CF ₃ ; R ¹ is a hydrogen atom, a linear or branched ether bond having 1 to 30 carbon atoms) At least one selected from the group consisting of an alkyl group that may be contained and a fluorinated alkyl group that may contain a linear or branched ether bond having 1 to 30 carbon atoms) Structural unit derived from one kind and Z or formula (5): X ² CH 2 ~ C

I (5)

COR ²

II

o

(Wherein, X ² is the same as X ¹ in the formula (4); a monovalent hydrocarbon group having 6 to 30 carbon atoms comprising R ² is an aromatic ring structure (aromatic ring), provided that R ² A part or all of the hydrogen atoms in the monomer may be substituted with a fluorine atom); a structural unit derived from at least one of the following monomers; structural unit A-2 is represented by the formula (1), (1) 4) and a structural unit derived from a monomer copolymerizable with the monomer shown in (5)], wherein 1 to 99 mol% of the structural unit A-1 and the structural unit A are contained in the polymer. Preferably, the structural unit contains 0 to 98 mol% of —2. The second of the preferable polymers of the present invention is that the structural unit M1 having an alicyclic hydrocarbon site in the side chain in the formula (M-1) is 1 to 99 mol%, and the alicyclic hydrocarbon site is It is a polymer containing 1 to 99 mol% of structural unit A-1 not containing, and 0 to 98 mol% of arbitrary structural unit A-2.

By introducing a structural unit derived from the monomer of the formula (4), mechanical properties and transparency can be imparted, and the refractive index can be adjusted (for example, set to PMMA or higher by increasing the refractive index). It is.

By introducing a structural unit derived from the monomer of the formula (5), further heat resistance, mechanical properties, and low water absorption can be imparted. Further, the refractive index can be adjusted (for example, PMMA or more by increasing the refractive index). Is set to).

When X ¹ and X ² in the structural unit A-1 are structural units derived from methacrylate, which is CH ₃ , it is preferable in that heat resistance, transparency, and a function of adjusting a refractive index can be more effectively imparted.

In addition, when X ¹ and X ² in the structural unit A-1 are structural units derived from α-fluoroacrylate, which is an F atom, heat resistance and mechanical strength, particularly bending It is preferable in that it can impart strength and further flexibility.

That is, it is preferable that the structural unit A-1 is a structural unit derived from at least one monomer selected from methyl methacrylate and methyl-α-fluoroacrylate. Can be granted.

When the structural unit A-1 is a structural unit derived from at least one monomer selected from phenyl methacrylate and phenyl α-fluoroacrylate, it is preferable in that it can impart further heat resistance and low water absorption. . The ratio of the structural unit Μ1 to A-1 may be 1 to 99 mol% of Ml and 1 to 99 mol% of structural unit A-1, but M1 + A-1 = 100 mol%. Preferably, the ratio of Ml / A-1 is 5/95 to 90/10 mol%, more preferably 595 to 60/40 mol%, particularly preferably 10 × 90 to 50/50 mol%. Preferably, the ratio is 10/90 to 40/60 mol%.

In the polymer of the present invention comprising the polymer of the formula (M-1) and the structural unit of the formula (M-3), X in the structural unit Ml derived from the monomer of the formula (1) is preferably an F atom. Preferably, heat resistance and mechanical strength, particularly bending strength, and further flexibility can be imparted.

Z forming a side chain in the polymer of the present invention containing the structural unit of the formula (M-1) and the polymer containing the structural unit of the formula (M-3), the side in the polymer containing the structural unit of the formula (M-2) ZZ ² forming a chain is an organic group having 3 to 30 carbon atoms and having an alicyclic hydrocarbon moiety therein.

The alicyclic hydrocarbon moiety may be a monocyclic hydrocarbon moiety, a multicyclic hydrocarbon moiety, or a hydrocarbon moiety containing any of them.

When the alicyclic hydrocarbon moiety includes a monocyclic hydrocarbon moiety, ζ, τ

Zeta ² is preferably a number of 7 or more organic groups carbon, it'll connexion than effective As a result, heat resistance can be imparted.

In particular, ζ and τζ ² are preferably an organic group containing a hydrocarbon moiety having a double ring structure, and can more effectively impart heat resistance and transparency.

Ζ when containing a hydrocarbon moiety having a monocyclic structure,

ζ ² is, specifically,

(1) an organic group having a cyclopentyl group and a derivative thereof,

(2) an organic group having a hexyl group and a derivative thereof,

(3) an organic group having a perhydrobiphenyl group and a derivative thereof,

(4) Spiro [4, 4] nonane and an organic group having a derivative thereof,

(5) Spiro [4,5] organic groups having decane and its derivatives are preferred, and as examples of some of them,

And so on.

Further, the hydrogen atoms of these exemplified hydrocarbon groups may be substituted with an alkyl group having 1 to 5 carbon atoms, a fluorine atom, or a functional group.

含む, 含む ζ ^{2 in the} case of containing a hydrocarbon moiety having a multiple ring structure, specifically,

(6) an organic group having adamantane and a derivative thereof,

(7) an organic group having norbornane and a derivative thereof,

(8) an organic group having parahydroanthracene and a derivative thereof, (9) an organic group having perhydronaphthylene and a derivative thereof,

(10) tricyclo [5.2.2 1.0 ^{^2'6]} The organic group having a decane and derivatives thereof

And some of them.

And so on.

Further among organic groups containing a hydrocarbon portion of these double ring structure, double ring structure consisting Adamanta down and its derivatives, Noruporunan and its derivatives or Ranaru double ring structure, tricyclo [5 .. 2. 1.0 ² ' ⁶ ] Those containing a double ring structure composed of decane and a derivative thereof are preferable, and these can particularly effectively impart heat resistance and transparency to the polymer.

Polymer and the formula (M- 2) and (M- 3) structure _¾ side chains that have a hydrocarbon moiety of alicyclic structure in the polymer containing structural units of the formula (M- 1) of the present invention monomer capable of forming the unit (formula (1) (2) and (3)) is specifically the Z, in Akuriru monomer which have at least one side chain structure selected from the ZZ ² There are, for example, the following.

(I) Monomers having an organic group in the side chain containing norpolnane and its derivatives

(Where X is H, F, Cl, CH ₃ or CF ₃ ; R ^la , R ^2a , R ^3a , R ^4a , R ^5a , R ^6a , R ^7a , R ^8a , R ^9a , R ^10a are the same Or different, H, F, C 1 or an alkyl group which may be substituted by a halogen atom having 1 to 14 carbon atoms; R 11a has 1 to 6 carbon atoms which may include ^a bond or a branched chain; Alkylene group; n is 0, an integer of 1-2)

More specifically,

And so on.

(II) Monomers having an organic group in the side chain containing adamantane and its derivatives

Koyo

-? n

(Where X is HFC 1 CH ₃ CF ₃ ; R ¹ R ^2b is a substituent bonded to the ring, CH ₃ C ₂ H ₅ or OH; R ^4b R ^5b has a bond or a branched chain. R ^3b is HCH ₃ or C ₂ H ₅ ; n is an integer of 0 or 12), and more specifically,

And so on.

(III) tricyclo [5.2.2 1.0 ² ^'6] decane and monomer having a derivative thereof including organic group in the side chain

(Wherein, X is H, F, C 1, CH 3 or _{^{^{CF 3; R 1 'R 2C}}} , R 3C, R

4 c 5 c R6C D7C R8C 9 C 10 C Ό 11 <R12C R l 3 c

R ^14C and R ^15E are the same or different, and may be an alkyl group having 1 to 14 carbon atoms which may be substituted with H, F, CI or a halogen atom; R ^16C may have a bond or a branched chain. (Good alkylene group with 1 to 6 carbon atoms)

(Where X is H, F, Cl, CH ₃ or CF ₃ ; R ^ld , R ^2d , R ^3d , R ^4d , R ^5d , R ^6d , R ^7d , R ^8d _¾ R ^9d _¾ R ^10d , R ^lld _¾ R ^12d and R ^13d are the same or different and are an alkyl group having 1 to 14 carbon atoms which may be substituted with H, F, C 1 or a halogen atom; R ^{14 d} includes a bond or a branched chain (Alkylene group having 1 to 6 carbon atoms which may be present)

More specifically,

And so on.

In the polymer of the present invention containing the structural unit of the formula (M-3), specific examples of the monomer forming the structural unit A-1 include the following.

Specific examples of the monomer having a chain hydrocarbon group of the formula (4) in the side chain include:

/ ^J

CH ~ C C —Q

C-0- (CH ₂ ) n- (CF ₂ ) mY C-0- (CH ₂ ) n- (CF ₂ ) mY

II

0 O

CF ₂ ) mC ₂ F ₅

CH

CH—C _v

CH ~ C _x

CO— (CH ₂ ) mH

C-0- (CH ₂ ) mH

O

(Where n is an integer of 16 and m is an integer of up to 0 29. Y is H or F; R ^le R ^2e R ^3e is the same or different, and H is an alkyl which may contain an ether bond of 129 carbon atoms.) Or a fluorine-containing alkyl group which may contain an ether bond having 1 to 29 carbon atoms)

And so on.

More specifically

/ ^CH 3

c CH;

CH ", 2 ~ ^C \

C-O-C

CO— CH, II ³ II ³

o o

Among them, methacrylic acid, α-fluoroacrylic acid, acrylic acid, methyl methacrylate (ΜΜΑ), and methyl α-fluoroacrylate are excellent in the effects of improving transparency, heat resistance, and mechanical strength. preferable. In particular

ΜΜΑ is excellent in improving optical and mechanical properties.

Specific examples of the monomer having a hydrocarbon group containing an aromatic cyclic structure (aromatic ring) of the formula (5) in the side chain include:

(Where X ² is H, F, Cl, CH ₃ , CF RR 2 f RR 4 f

R ^{5 f} is the same or different and is an alkyl group having 1 to 14 carbon atoms which may be substituted by H, F, C 1 or a halogen atom; R ^{6 f} may have a bond or a branched chain A good alkylene group having 1 to 6 carbon atoms) and the like.

Are preferred. In the formula (5), the aromatic cyclic structure contained in R ² is not only an aromatic monocyclic structure such as a benzene ring, but also a multiple cyclic structure such as a naphthylene ring or an anthracene cyclic structure, or a pyridine ring. It may be a structure in which two or more aromatic cyclic structures such as phenyl are continuously connected.

Among them, phenyl methacrylate .. phenyl methacrylate is preferred from the viewpoint of improving heat resistance.

The molecular weight of the polymer used in the heat-resistant optical material of the present invention is generally in the range of 2000 to 1,000,000 in number average molecular weight, preferably 10,000 to 500,000, particularly preferably 50,000 to 300,000. Low An excessively high molecular weight is not preferable because mechanical properties, particularly, bending strength and flexibility are reduced. On the other hand, a molecular weight that is too high is not preferred because moldability is reduced and transparency is reduced due to an increase in light scattering.

The polymer used in the heat-resistant optical material of the present invention has a heat distortion temperature of 115 ° C. or higher, which suppresses softening even in a high-temperature environment. Signal transmission (transmission with little loss of optical signal over long distances) becomes possible.

The heat distortion temperature in the present invention means a deflection temperature under load (HDT), and uses a value measured by a method standardized by ASTM D684. In particular, the heat distortion temperature is preferably 12 Ot: or more, especially 130 ° C or more, and more preferably 140 ° C or more.The high heat deformation temperature makes it possible to control automobiles, especially around engine parts, and aircraft. It is advantageous for optical components, optical communication media, plastic optical fibers, etc. used in high-temperature environments, such as for controlling air conditioners and controlling industrial mouth pots.

The heat-resistant optical material of the present invention needs to have high transparency to light in the visible region, and particularly preferably has high transparency to light having a wavelength of 650 nm.

From this viewpoint, the heat-resistant optical material of the present invention preferably has an extinction coefficient at 65 Onm wavelength light of 0.015 cm- ¹ or less, particularly 0.014 cm- ¹ or less, and more preferably 0.015 cm- ¹ or less. It is preferably cm- ¹ or less. As a result, the absorption loss of the optical signal can be reduced, and the loss can be reduced even when transmitting the optical signal over a long distance of 2 Om to 10 Om.

Here, the extinction coefficient means that a plastic optical fiber having a length of 10 Omm is manufactured by using a heat-resistant optical material of the present invention as a core material by melt-spinning with a clad material having an appropriate refractive index and a wavelength of 650 nm. Measure transmitted light intensity with light at nm. The incident light intensity iota _beta, when the transmitted light intensity, the absorption coefficient under Refers to the value calculated by the formula.

Extinction coefficient = 1 κ 10 · 1 og ( 1 0/1 ^

The heat-resistant optical material of the present invention can adjust the refractive index in a wide range. Thus, it can be used for optical transmission media or cladding.

In particular, since the heat-resistant optical material of the present invention has high transparency and can be adjusted to a high refractive index, it can be used for an optical transmission medium, for example, a core of a plastic optical fiber / optical waveguide element.

In that case, heat resistant optical material refractive index of the present invention: n _D 1. 45 or more der Rukoto are preferred.

The refractive index uses the value measured using an Abbe's refractometer at 25 using sodium D line as a light source.

The refractive index is preferably 1.47 or more, more preferably 1.48 or more, and the most preferred range is 1.48 to 1.52. If the refractive index is too low, it is not preferable because the choice of the material on the cladding material side is restricted when fabricating the plastic optical fiber. If the refractive index is too high, the transmission loss due to light scattering increases, and the coupling loss increases when joining the plastic optical fibers.

Above structural units and properties have been in terms of (characteristics) have been the description, _c polymer describing a preferred embodiment of the polymers used in the heat-resistant optical material of the present invention in the following (I)

Formula (M-4):

― [Ml — l a] — [A— l a]-(M—4)

[Where the structural unit Ml-1a is the formula (2-1): CH ₂ = CF

COZ ³ (2-1)

II

o

(Wherein, z ³ is Adamantan and its derivatives, Noruporunan and derivatives thereof, tricyclo [5.2.2 1.0 ^{^2'6]} hydrocarbon moiety of decane and at least one double ring structure derivatives or selected A monovalent organic group having 10 to 30 carbon atoms); Structural unit A—1a is a structural unit derived from methyl methacrylate], and 1 to 100 mol% of structural unit Ml—1a; From 0 to 99 mol%.

This polymer is preferred because it has high transparency and excellent mechanical strength, particularly excellent bending strength and flexibility.

Polymer (II)

Equation (M-5):

One [Ml—la]-[A-la]-[A-2a]-(M—5)

(Wherein, the structural units Ml-1a and A-1a are the same as those in the above formula (M-4); the structural unit A-2a is a structural unit derived from phenyl methacrylate or phenyl-1-a-fluoroacrylate). A polymer containing 1 to 99 mol% of the structural unit Ml-la, 0 to 98 mol% of the structural unit A-1a, and 1 to 99 mol% of the structural unit A-2a.

This polymer is preferred because it has excellent heat resistance and low water absorption.

Polymer (ΙΠ)

Equation (M-6):

One [Ml-1a]-[Ml-2a]-[A-1a]-(M-6)

[Wherein the structural units Ml-la and A-la are the same as in the above formula (M-4); the structural unit M1-2a is the formula (3-1): CH ₃

I

C H 2 ~ C

(3-1)

coz ⁴

II

o

(Wherein, z ⁴ is Adamantan and its derivatives, Noruporunan and derivatives thereof, tricyclo [5.2.2 1.0 ^{^2'6]} hydrocarbon moiety of decane and at least one double ring structure derivatives or selected Monovalent organic group containing 10 to 30 carbon atoms)

A polymer comprising 1 to 99 mol% of a structural unit M 1-la, 1 to 99 mol% of a structural unit M 1-2a, and 0 to 98 mol% of a structural unit A-1a.

This polymer is preferred because it has excellent heat resistance and mechanical strength, particularly excellent bending strength, and is easy to adjust the refractive index.

When the heat-resistant optical material of the present invention is used particularly for a core, additives may be mixed within a range that does not impair heat resistance or signal transmission performance.

For example, to adjust the refractive index, benzyl phthalate-n-butyl (refractive index: 1.575), 1-methoxyphenyl-2-phenylene (refractive index: 1.571), benzyl benzoate (refractive index: 1.568), bromobenzene (refractive index: 1.557), o-dichlorobenzene (refractive index: 1.551) m-dichlorobenzene (refractive index: 1.543) _¾ 1, 2'-dibromoethane (Refractive index: 1.538), 3-phenyl-1-propanol (refractive index: 1.532), diphenylphthalic acid (C ₆ H ₄ (COOC ₆ H ₅ ) ₂ ), triphenyl phosphine ((C ₆ H ₅₎ ₃ P) and dibenzyl phosphate Feto ((C ₆ H ₅ CH ₂ 〇) ₂ PH0 _2), 4, 4, one dibromobenzyl, 4, 4 'single dibromo Biff enyl, 2, 4' - jib Mouth moacetophenone, 3,, 4, dichloroacetophenone, 3, 4 dichloroaniline, 2, 4 2,6-Jib mouth moaniline 1,4-dibromobenze A compound such as a compound can be added. These low molecular weight compounds not only simply adjust the refractive index of the heat-resistant optical material of the present invention uniformly, but also, for example, a refractive index distribution (graded grade) described in JP-A-8-110420. It functions as a dopant for obtaining an index-type optical fiber. The heat resistant optical material of the present invention is also useful for obtaining a heat resistant refractive index distribution (graded index) type optical fiber.

It is preferable to use the heat-resistant optical material of the present invention as an optical transmission medium and a core material of a plastic optical fiber formed of a core and a clad.

Since the above plastic optical fiber using the heat resistant optical material of the present invention has high heat resistance, it is useful when 100 or more heat resistance is required. For example, in a light guide, heat resistance is required when laying a plastic optical fiber close to an octogen light source. In one sensor application, heat resistance is required to detect the parts where the atmosphere becomes hot, such as the detection of headlight illumination of a car and the positioning sensor of a melting press. The same applies to sensors in industrial lopots. For optical communication applications, heat resistance of 100 ° C or more is required, for example, when wiring in the engine room, the ceiling of a car, or the instrument panel where the temperature is high in an in-vehicle LAN. The same applies to the case where it is mounted on an aircraft. Plastic optical fibers in factory-automation (FA) applications also require heat resistance when exposed to high-temperature environments. In addition, even when used outdoors or indoors, heat resistance is required due to the environment where there is no ordinary air conditioning equipment such as a distribution panel room on the roof of a pill or a communication base station. The heat-resistant optical material of the present invention can be effectively used for these uses.

These optical materials used for the plastic optical fiber cladding using the heat-resistant optical material have a glass transition temperature of 10 ° C. or more and a refractive index (n _D ) of 1.44 or less. Preferably, there is. The optical material used for the clad preferably has a glass transition temperature of 105 or more, more preferably 110 ° C or more, further preferably 120 ° C or more, particularly 130 ° C or more. Heat resistance can be improved by having a high glass transition temperature, and it is preferable in that a high heat-resistant plastic optical fiber can be formed in combination with the heat-resistant optical material of the present invention used for the core. It can be used more effectively in applications where

The preferred polymer used as the heat-resistant cladding has a refractive index of 1.

A fluorinated acryl-based resin of 44 or less is usually used, and a methacrylate having a fluoroacrylyl group in a side chain, a (co) copolymer of CK-fluoroacrylate and the like are preferable. Among them, as a fluorine-containing acrylate having both heat resistance (high glass transition temperature) and low refractive index, formula (6):

(Wherein X ³ is H, CH ₃ , F, CF ₃ or C 1; R f ¹ and R f ² are the same or different, and is a perfluoroalkyl group having 1 to 5 carbon atoms; W is fluorine) A polymer having a structural unit (a) represented by the following formula: (hydrocarbon group having 1 to 5 carbon atoms which may be substituted by an atom) is preferable.

In particular, a fluorine-containing copolymer composed of the structural unit of the above formula (6) and a structural unit derived from methyl methacrylate is preferable. For example, a structural unit (a) of the above formula (6) and a structural unit (b) derived from methyl methacrylate are preferred. When the total is 100, a fluorine-containing copolymer having a ratio of (a) / (b) 32 68 to 64/36 mol% is preferred.

The layer structure of the plastic optical fiber is generally composed of a core layer and a cladding layer from the inside. The caliber is not particularly limited, but usually from 125 l mm. The thickness of each layer is usually about core layer Z cladding layer = 98 Z 2, and the core layer occupies the majority. Further, a protective layer may be provided on the outer periphery. This protective layer is mainly used for the purpose of improving heat resistance, reducing bending loss, and improving impact resistance. Usually, a vinylidene fluoride copolymer is used. Among them, a vinylidene fluoride Z tetrafluoroethylene copolymer is preferable. The thickness of the protective layer is almost the same as that of the cladding layer. When used as an optical fiber cable, a coating layer is further arranged on the outer periphery. As the coating layer, conventionally used nylon 12, polyvinyl chloride, polyethylene, polyurethane, polypropylene and the like can be used.

In the above-mentioned configuration, the one in which the core layer has a single refractive index is called an SI (step index) type plastic optical fiber, which is the most common.

The one in which the refractive index of the core layer decreases stepwise from the inner circumference to the outer circumference is called a multi-step plastic optical fiber. A fiber whose refractive index decreases smoothly from the inner circumference to the outer circumference is called a GI (graded index) plastic optical fiber.

As a method for producing the plastic optical fiber, for example, in the case of the SI type plastic optical fiber, the core material polymer and the clad material polymer are arranged concentrically using a composite spinning nozzle, and melt composite spinning is performed. In general, a method of forming into a par and then performing a stretching treatment under heating for the purpose of improving the mechanical strength is used.

The heat-resistant optical material of the present invention can be preferably used also as a core of an optical waveguide element, and specific examples of the same polymer as the core material and the clad material can be similarly preferably exemplified.

FIG. 1 illustrates a main structure of a typical optical waveguide device. Where 1 is the base A plate, 2 is a core portion, and 3 and 4 are clad portions. Such an optical waveguide device is used to connect between optical functional devices, and light transmitted from a terminal of one of the optical functional devices passes through the core portion 2 of the optical waveguide device, for example, the core portion 2 and the clad portion. While repeating total reflection at the interface with 3 and 4, it is propagated to the other optical functional device terminal. The type of the optical waveguide element can be an appropriate type such as a planar type, a strip type, a ridge type, and a buried type.

Further, the optical material of the present invention can be used for the core portion and the clad portion of the above-mentioned optical functional device. The optical material of the present invention may be used only for the core portion or only the clad portion.

In addition, various functional compounds, for example, a nonlinear optical material, a functional organic dye having a fluorescent property, a photorefractive material, and the like are contained in the optical material of the present invention, and are used for a core portion of a waveguide type optical functional element. It is also possible.

Optical waveguide devices include, for example, devices that perform operations such as switching, amplification, wavelength conversion, optical multiplexing / demultiplexing, and wavelength selection on optical communication signals, such as optical switches, optical routers, ONUs, and media converters. Available.

The heat-resistant optical material of the present invention may be used for other purposes other than the above, for example, for lenses (pickup lenses, lenses for glasses, lenses for cameras, Fresnel lenses for projects, contact lenses), sealing for luminous bodies such as LEDs. Materials, anti-reflective materials, optical disc substrates, cover materials for lighting equipment, display protection plates, transparent cases, display boards, automotive parts, etc.

Next, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples.

Example 1

2-Methyl-2-adamantyl <<-Fluoroacrylate 30 g, methyl methacrylate (MMA) 70 g, n-laurylmercapone 0.1 g, azoisobutyronitrile 0.02 5 8 5 0 0111 Inside the glass flask The mixture was dissolved and mixed in, degassing and nitrogen substitution were repeated, and after sealing, polymerization was carried out at 70 ° C for 16 hours.

After completion of the polymerization, 300 g of acetone was added to the product to dissolve it, and the obtained solution was poured into 5 liters of methanol. The precipitated polymer was separated from the liquid, and dried under reduced pressure at a temperature of 100 for 10 hours to obtain 92 g of a solid polymer (92% yield).

The obtained polymer was measured by ¹⁹ FNMR, 'HNMR and IR methods to confirm that it was a copolymer of 2-methyl-2 adamantyl α-fluoroacrylate / MMA = 15/85 (mol%).

In addition, the weight average molecular weight, refractive index, glass transition temperature, heat distortion temperature, melt index, P and light coefficient, and tensile strength of the obtained copolymer were examined. Table 1 shows the results.

The physical property values are measured by the following methods.

(1) Weight average molecular weight (Mw)

Measured by GPC method (polystyrene conversion).

(2) Refractive index (n _D )

Measure at 25 ° C using an Abbe refractometer manufactured by Atago Optical Instruments Co., Ltd. using sodium D line as a light source.

(3) Glass transition temperature (Tg)

Using a DSC (Differential Scanning Calorimeter) manufactured by Seiko Denshi Co., Ltd., raise the 1st run to 200 at a heating rate of 101: / min, maintain it at 200 for 1 minute, and then cool it to 25 at a cooling rate of 10Ό / min. After cooling, the midpoint of the endothermic curve of the 2nd run obtained at a heating rate of 10 / min is defined as Tg.

(4) Heat distortion temperature (HDT)

Use an HDT tester manufactured by Toyo Seiki Seisaku-sho, Ltd. to measure according to ASTM D6844. (5) Melt index (MI)

Each of the copolymers was mounted on a 9.5 mm inner diameter cylinder and maintained at a temperature of 230 for 5 minutes using a drop-down type flow tester manufactured by Shimadzu Corporation. Extruded through an lmm, 8 mm long orifice and expressed in grams of copolymer extruded in 10 minutes.

(6) Absorption coefficient (ε)

Using polymer as core material and cladding material from 2,2,2-trifluoroethyl methacrylate 50% by weight, 2,2,3,3-tetrafluoropropyl methacrylate 30% by weight, methyl methacrylate 20% by weight Using a co-polymer, the composite fiber is spun at 230 to produce a plastic optical fiber with a diameter of 300 m (cladding material thickness 15) and a length of 100 mm. The transmittance of the optical fiber is measured with light at a wavelength of 650 nm. Incident light intensity I. When the transmitted light intensity is, the extinction coefficient and ε are calculated by the following formula.

(7) Tensile strength (F)

The tensile strength is measured using a universal tester manufactured by Shimadzu Corporation according to ASTM D638.

Example 2

A copolymer was obtained in the same manner as in Example 1, except that 15 g of isobornyl a-fluoroacrylate, 15 g of phenyl Q! -Fluoroacrylate, and 70 g of MMA were used as monomers. Was. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results.

Example 3

Same as Example 1 except that 40 g of tricyclodecanyl monofluoroacrylate and 60 g of methyl monofluoroacrylate were used as monomers To obtain a copolymer. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results.

Example 4

A copolymer was obtained in the same manner as in Example 1 except that 25 g of 2-methyl-2 adamantyl α-fluoroacrylate, 25 g of isopolnyl methacrylate and 50 g of MMA were used as monomers. Was. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results. Example 5

In the same manner as in Example 1 except that 15 g of cyclohexyl α-fluoroacrylate, 25 g of phenyl α-fluoroacrylate and 60 g of methyl α-fluoroacrylate were used as monomers. A copolymer was obtained. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 1

A homopolymer of MMA was obtained in the same manner as in Example 1 except that only 100 g of MMA was used as a monomer. Various physical properties of the obtained polymer were measured in the same manner as in Example 1. Table 1 shows the results.

Comparative Example 2

A copolymer was obtained in the same manner as in Example 1, except that 30 g of phenylmethyl acrylate and 70 g of MMA were used as monomers. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results. Comparative Example 3

A copolymer was obtained in the same manner as in Example 1 except that 25 g of 2,2,2-trifluoroethyl α-fluoroacrylate and 75 g of maraudal A were used as monomers. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results. Comparative Example 4

The copolymer was prepared in the same manner as in Example 1 except that 50 g of 2,2,3,3,3-pentanofluoropropyl α-fluoroacrylate and 50 g of phenyl methacrylate were used as monomers. Got. The composition and various physical properties of the obtained copolymer were measured in the same manner as in Example 1. Table 1 shows the results.

table 1

Example""

2 3 4 5 2 Copolymer composition, 2 1 -methylisopolditricyclo 2-methylcyclohexyl α- Fluoroacrylate h Fluoroacrylate Acrylate (21) Crylate (8) Crylate (11)

(15) (24) (15)

ΜΜΑFenizole α | ソ isoporni I Phenyl α MMA (85) —Fluoro (76) Lume evening Fluoro (79)

Ura (16) Ura

(11) (18)

ΜΜΑ メチル methyl a-

(81) (69) Fluororea

Acrylate

(7 1)

Physical properties

Mw 220,000 310,230,300,250,000 260,330,000 Refractive index 1.502 1.497 1.486 1.510 1.474 1.492 1.514 Tg (° C) 147 140 156 165 139 139 105 120 HDT CC) 130 121 139 140 117 90 105 MI (g / lOmin) 32 41 33 38 44 39 40 Absorption coefficient (Zcm) 0.0098 0.0108 0.0129 0.0125 0.0122 0.0046 0.015 Tensile strength (MPa) 70 68 61 62 72 63 50

Synthesis example 1

The same procedure as in Example 1 was repeated except that 50 g of 2,2-bis (trifluoromethyl) propanyl methacrylate, 20 g of MMA, and 30 g of 1H, 1H, 3H-tetrafluoropropyl methacrylate were used as monomers. A polymer was obtained. The glass transition temperature of the obtained polymer was 110 ° C, the MI was 37 g / 10 min, and the refractive index was 1.419.

Example 6

2,2,2-Trifluoroethyl methacrylate 50% by weight, 2,2,3,3-tetrafluoromethyl propyl methacrylate 30% by weight, methyl methacrylate 20% by weight using the polymer of Example 1 as a cladding material as a core material %, And a composite optical fiber having a diameter of 300 zm (sheath thickness 15 m) and a length of 50 m was produced by composite spinning at 23 Ot :. The transmission loss of this plastic optical fiber was measured at a wavelength of 65 Onm at an incident NA of 0.1 using the cutback method of 25m-5m. The plastic optical fiber was kept at 100 ° C for 168 hours, and the transmission loss at a wavelength of 650 nm was measured in the same manner. Table 2 shows the results.

Example 7

A plastic optical fiber 1 was obtained in the same manner as in Example 6, except that the polymer of Example 4 was used as the core material and the polymer of Synthesis Example 1 was used as the clad material. Table 2 shows the characteristics of the obtained plastic optical fiber.

Comparative Example 5

A plastic optical fiber was obtained in the same manner as in Example 6, except that the polymer of Comparative Example 3 was used as the core material. Table 2 shows the characteristics of the obtained plastic optical fiber. Table 2

Industrial applicability

According to the present invention, an optical material having both heat resistance and signal transmission ability can be provided.

In addition, optical transmission media, specifically optical materials with signal transmission capabilities that can be used as core materials for plastic optical fibers and waveguide devices, especially the 125 ° C environment required in automobile engine rooms Or a plastic optical fiber made of an optical material that can be used in a 150 ° C environment required in an engine room of a diesel car.

Claims

Scope of Word

1. A heat-resistant optical material comprising a polymer having an alicyclic hydrocarbon moiety in a side chain, wherein the polymer having an alicyclic hydrocarbon moiety in a side chain has a heat deformation temperature of 115 ° C or more. Yes, and the formula (M-1):

— [Ml]-[A] _ (M-1)

The structural unit Ml has the formula (1):

X

C JT12 ~ ^

I (1)

c-o- Z

II

o

(Wherein, X is at least one member selected from the group consisting of H, CH ₃ , F, C 1 and CF ₃ ; Z is C 3-30 having an alicyclic hydrocarbon moiety)

A structural unit derived from at least one of the monomers represented by (monovalent organic group), and the structural unit A is a structure derived from at least one of the monomers copolymerizable with the monomer of the formula (1) A heat-resistant optical material which is a polymer containing 1 to 100 mol% of the structural unit Ml and 0 to 99 mol% of the structural unit A.

2. The structural unit Ml of the polymer having an alicyclic hydrocarbon moiety in the side chain is represented by the formula (M-2):

-[M 1-1] one [Ml-2] ― (M-2)

Inside

The structural unit Ml—1 is the formula (2): CH ₂ = CF

COZ ¹ (2)

II

〇

(Wherein, Z ¹ is a monovalent organic group having 3 to 30 carbon atoms having an alicyclic hydrocarbon moiety), and a structural unit derived from at least one kind of a monomer represented by the following formula: Equation (3):

X ³

I (3)

coz ²

o

(Wherein X ³ is at least one selected from the group consisting of H, CH ₃ , C 1 and CF ₃ ; Z ² is a monovalent organic group having 3 to 30 carbon atoms and having an alicyclic hydrocarbon moiety) ) Structural units derived from at least one of the monomers represented by the formula], wherein the structural unit contains 1-199 mol% of the structural unit M1-1 and 1-99 mol% of the structural unit M1-2. 2. The heat-resistant optical material according to claim 1.

3. The structural unit A of the polymer having an alicyclic hydrocarbon moiety in the side chain is represented by the formula (M-3):

One [A-1]-[A-2]-(M-3)

[Where,

Structural unit A—1 is the formula (4):

X ¹

CH ₂ = C

(Four)

COR ¹

O (Wherein X ¹ is at least one selected from the group consisting of H, CH ₃ , F, C 1 and CF ₃ ; R ¹ is a hydrogen atom, a linear or branched ether bond having 1 to 30 carbon atoms) At least one selected from the group consisting of an alkyl group which may contain a fluorinated alkyl group which may contain a linear or branched ether bond having 1 to 30 carbon atoms) And / or a structural unit derived from at least one of the following:

X ²

I

C-1-1 R ²

II

o

(Wherein X ² is the same as X ^{1 in the} formula (4); R ² is a monovalent hydrocarbon group having 6 to 30 carbon atoms including an aromatic ring structure, provided that a hydrogen atom in R ² A part or all of which may be substituted with a fluorine atom); a structural unit derived from at least one monomer represented by the formula:

A structural unit derived from a monomer copolymerizable with the monomers shown in (4) and (5)], and 1 to 99 mol% of the structural unit A-1 and the structural unit A in the polymer. 3. The heat-resistant optical material according to claim 1, which is a structural unit containing 0 to 98 mol% of 2.

4. The heat-resistant optical material according to claim 3, wherein the structural unit A-1 is a structural unit derived from at least one of the monomers represented by the formula (4).

5. The heat-resistant optical material according to claim 4, wherein the structural unit A-1 is a structural unit derived from methyl methacrylate or methyl-α-fluoroacrylate.

6. The heat-resistant optical material according to claim 3, wherein the structural unit Α-1 is a structural unit derived from at least one of the monomers represented by the formula (5).

7. The structural unit A-1 is phenyl methacrylate or phenyl- 7. The heat-resistant optical material according to claim 6, which is a structural unit derived from fluoroacrylate.

8. The heat-resistant optical material according to any one of claims 1 or 3 to 7, wherein X in the formula (1) is F.

9. The heat resistance according to any one of claims 1 to 8, wherein Z in the formula (1) is a monovalent organic group having 4 to 30 carbon atoms and having a hydrocarbon moiety having a bicyclic structure. Optical materials.

10. The claim according to claim ² , wherein at least one of Z ^{1 in the} formula (2) and Z 2 in the formula (3) is a monovalent organic group having 4 to 30 carbon atoms and having a hydrocarbon moiety having a double ring structure. 9. The heat-resistant optical material according to any one of items 8 to 8.

11. The monovalent organic group having a hydrocarbon moiety having a multiple ring structure is an organic group having 10 to 30 carbon atoms including a multiple ring structure composed of adamantane or a derivative thereof. Item 10. The heat-resistant optical material according to item 10.

12. The scope of claim 9 or claim 9, wherein the monovalent organic group having a hydrocarbon moiety having a multiple ring structure is an organic group having 7 to 30 carbon atoms including a multiple ring structure composed of norpolnane or a derivative thereof. Item 10. The heat-resistant optical material according to item 10.

13. When the monovalent organic group having a hydrocarbon moiety having a double ring structure is tricyclo [5.

2. 1.0 ² ' ⁶ ] The heat-resistant optical material according to claim 9 or 10, which is an organic group having 10 to 30 carbon atoms including a double ring structure composed of decane or a derivative thereof.

14. The heat resistance according to any one of claims 1 to 13, wherein the polymer having an alicyclic hydrocarbon moiety in the side chain is a polymer having a heat distortion temperature of 130 or more. Optical materials.

15. The polymer according to claim ¹ , wherein the polymer having an alicyclic hydrocarbon moiety in the side chain is a polymer having an extinction coefficient at a wavelength of 600 nm of 0.015 cm- ¹ or less. Item 15. The heat-resistant optical material according to any one of Items 14 to 14.

16. polymers having an alicyclic hydrocarbon moiety to the side chain, the refractive index n _D is 1.4 to 5 or more polymerizable first term range of body and is claimed - first item 5 according to any one Heat resistant optical material.

17. polymers having an alicyclic hydrocarbon moiety to the side chain, the refractive index n _D is 1.

The heat-resistant optical material according to any one of claims 1 to 15, which is a polymer of 47 or more.

18. An optical transmission medium using the heat-resistant optical material according to any one of claims 1 to 17.

19. A plastic optical fiber comprising a core and a clad, wherein the core comprises the optical transmission medium according to claim 18.

20. The cladding has a glass transition temperature of 100 ° C. or higher and a refractive index n _D of 1.

44. The plastic optical fiber according to claim 19, wherein the plastic optical fiber is a material of 4 or less.

21. The plastic optical fiber according to claim 20, wherein said cladding is made of a material having a glass transition temperature of 105 ° C or more.

22. The plastic optical fiber according to any one of claims 19 to 21 which is a plastic optical fiber for LAN mounted on a vehicle.

23. An optical waveguide device comprising a core and a clad, wherein the core uses the optical transmission medium according to claim 18.