JP6739255B2 - Thermoplastic resin - Google Patents

Description

The present invention relates to a thermoplastic resin and an optical lens. More specifically, it relates to a thermoplastic resin having a specific ester structure having a high refractive index, a low birefringence and a high heat resistance, and an optical lens made of the same.

Optical glass or optical resin is used as a material for an optical lens used in an optical system of various cameras such as a camera, a film-integrated camera, and a video camera. Optical glass is excellent in heat resistance, transparency, dimensional stability, chemical resistance, etc., but has the problems of high material cost, poor moldability, and low productivity.

On the other hand, an optical lens made of an optical resin has an advantage that it can be mass-produced by injection molding, and polycarbonate, polyester carbonate, polyester resin or the like is used as a high refractive index material for a camera lens. However, in recent years, development of resins having a high refractive index has been required due to the lighter, thinner, shorter and smaller products. Generally, when the refractive index of an optical material is high, a lens element having the same refractive index can be realized by a surface having a smaller curvature, so that the amount of aberration generated on this surface can be reduced, the number of lenses can be reduced, and It is possible to reduce the polarization sensitivity and reduce the lens thickness to reduce the weight.

When the optical resin is used as an optical lens, heat resistance, transparency, low water absorption, chemical resistance, low birefringence and wet heat resistance are required in addition to the refractive index and Abbe number. In particular, in recent years, a camera lens having a lower birefringence has been demanded as the resolution is improved by improving the number of pixels. In general, as a method of reducing the birefringence, there is a method of canceling out the birefringence between the compositions having positive and negative birefringence with different signs. Therefore, the composition ratio of these materials having birefringence of opposite signs is very important.

Patent Document 1 includes, as a monomer component, a biaryl compound which is bound by a bond axis capable of imparting internal rotational isomerism and at least one aryl group has a π electron number of 4n+6 (n is a natural number) with respect to the bond axis. A resin composition is disclosed, which has characteristics such as excellent transparency, low optical anisotropy, a high refractive index, and low moisture absorption. Materials for optical lenses having refraction have not been obtained yet.

JP 2001-72872 A

Therefore, a first object of the present invention is to provide a thermoplastic resin having a high refractive index, a low birefringence and a high heat resistance, and particularly excellent in optical characteristics.
A second object of the present invention is to provide a thermoplastic resin having a particularly high degree of heat resistance and excellent optical characteristics in addition to the above first object.

The present inventors have conducted intensive studies to achieve this object, and as a result, have found that the thermoplastic resin represented by the following general formula (1) can solve the above problems, and have reached the present invention.

That is, the present invention is
1. A thermoplastic resin in which the repeating unit represented by the following general formula (1) contains 70 mol% or more of all the units.
(In the formula (1), R ¹ and R ² each independently represent a hydrocarbon group which may contain an aromatic group having 1 to 10 carbon atoms, and n and m each independently represent an integer of 0 or more. R ^{3 to} R ¹⁰ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. R ¹¹ and R ¹² are each independently represents an even better hydrocarbon group include an aromatic group having 1 to 10 carbon atoms, o and p is an integer of 0 or more each independently .R ¹³ and R ^14's each independently represent a hydrogen atom or a hydrocarbon group optionally containing an aromatic group having 1 to 20 carbon atoms.)

2. In the general formula (1), R ¹ and R ² are each a hydrocarbon group having 1 to 3 carbon atoms, n and m are each 0 or 1, and R ^{3 to} R ¹⁰ are each hydrogen. 2. The thermoplastic resin as described in 1 above, which is a hydrocarbon group which may contain an atom or an aromatic group having 1 to 12 carbon atoms.
3. The thermoplastic resin as described in 2 above, wherein in the general formula (1), R ¹ and R ² are each a methylene group, n and m are each 1, and R ^{3 to} R ¹⁰ are hydrogen atoms.
4. In the general formula (1), R ¹¹ and R ¹² are each a hydrocarbon group having 1 to 4 carbon atoms, o and p are each 0 or 1, and R ¹³ and R ¹⁴ are each hydrogen. 2. The thermoplastic resin as described in 1 above, which is a hydrocarbon group which may contain an atom or an aromatic group having 1 to 12 carbon atoms.
5. In the above general formula (1), R ¹¹ and R ¹² each represent an ethylene group, o and p each represent 1, and R ¹³ and R ¹⁴ each represent a hydrogen atom or a phenyl group. The thermoplastic resin described.
6. 6. The thermoplastic resin as described in any one of 1 to 5 above, which has a refractive index of 1.650 to 1.700.
7. 7. The thermoplastic resin as described in any one of 1 to 6 above, which has a specific viscosity of 0.12 to 0.40.
8. The thermoplastic resin according to any one of 1 to 7 above, which has a glass transition temperature of 128 to 160°C.
9. 9. The thermoplastic resin as described in any one of 1 to 8 above, which has an orientation birefringence of 0 to 4×10 ⁻³ .
10. The thermoplastic resin according to any one of 1 to 9 above, which is a polyester or polyester carbonate resin.
11. An optical member comprising the thermoplastic resin according to any one of 1 to 10 above.
12. An optical lens comprising the thermoplastic resin according to any one of 1 to 10 above.

Since the thermoplastic resin of the present invention has a high refractive index, a low birefringence and a high heat resistance, its industrial effect is exceptional.

3 is a proton NMR spectrum of the polyester carbonate resin obtained in Example 2.

The present invention will be described in more detail.
The thermoplastic resin of the present invention needs to contain 70 mol% or more of the repeating unit represented by the general formula (1), and a specific thermoplastic resin is preferably a polyester resin or a polyester carbonate resin. From the viewpoint of the effect of the present invention, a polyester resin is particularly preferable.

In the general formula (1), R ¹ and R ² each independently represent a hydrocarbon group which may contain an aromatic group having 1 to 10 carbon atoms, and n and m each independently represent 0 or more. Indicates an integer. R ^{3 to} R ¹⁰ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. R ¹¹ and R ¹² each independently represent a hydrocarbon group having 1 to 10 carbon atoms which may include an aromatic group, and o and p each independently represent an integer of 0 or more. R ¹³ and R ¹⁴ each independently represent a hydrocarbon group which may contain a hydrogen atom or an aromatic group having 1 to 20 carbon atoms.

R ¹ and R ² preferably each independently represent a hydrocarbon group having 1 to 3 carbon atoms, and n and m preferably each independently represent an integer of 0 or 1. R ^{3 to} R ¹⁰ preferably each independently represent a hydrogen atom or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. R ¹¹ and R ¹² are preferably each independently a hydrocarbon group having 1 to 4 carbon atoms, o and p are each independently an integer of 0 or 1, and R ¹³ and R ¹⁴ are Each independently represents a hydrocarbon group which may contain a hydrogen atom or an aromatic group having 1 to 12 carbon atoms.

Particularly preferably, R ¹ and R ² represent a methylene group, n and m represent 1, R ^{3 to} R ¹⁰ represent a hydrogen atom, R ¹¹ and R ¹² represent an ethylene group, and o and p Represents 1 and R ¹³ and R ¹⁴ represent a hydrogen atom or a phenyl group.

Further, R ¹ and R ² may be the same or different, n and m may be the same or different, and R ^{3 to} R ¹⁰ may be the same or different. R ¹¹ and R ¹² may be the same or different, o and p may be the same or different, and R ¹³ and R ¹⁴ may be the same or different. It may be.

The repeating unit represented by the general formula (1) is 70 mol% or more, preferably 75 mol% or more, more preferably 80 mol% or more, based on the total repeating units. Within this range, the heat resistance is excellent.

In the general formula (1), the 1,1′-binaphthyl skeleton improves the heat resistance and the refractive index of the thermoplastic resin and has a conformation orthogonal to the bond axis connecting the two naphthalene rings. Therefore, it has an effect of reducing birefringence.

The 1,1′-binaphthyl skeleton may be substituted with a substituent or may be condensed with each other. There are no particular restrictions on the substituents, and there are no particular limitations, but representative examples include alkyl, aryl, and the like. The alkyl group preferably has 1 to 12 carbon atoms and may be linear or branched. Examples of the aryl group include a phenyl group, a naphthyl group and a biphenyl group.

The binaphthyl skeleton may be any of R-form, S-form and racemic form, and preferably the racemic form. The racemate, which does not require optical resolution, has a cost advantage.

A first object of the present invention is to provide a high refractive index and high heat resistance, and a refractive index (hereinafter, may be abbreviated as nD) at a measurement wavelength of 589 nm at 25° C. is 1.650 to 1.700. Is preferred, 1.655 to 1.695 is more preferred, and 1.657 to 1.686 is even more preferred.
The glass transition point (hereinafter sometimes abbreviated as Tg) is preferably 128 to 160°C, more preferably 130 to 158°C.
Further, the relational expression between nD and Tg calculated from the result of the present implementation is
Tg>-850nD+1555 (1)
It is preferable that the relationship is satisfied.

A second object of the present invention is to provide a particularly high degree of heat resistance in addition to the above first object. Tg is 144 to 158 and nD is 1.657 to 1.674. It is more preferable that the Tg is 150 to 155° C. and the nD is 1.659 to 1.673.

When Tg and nD are within the above ranges, in addition to high refractive index and low birefringence, it is further excellent in balance between heat resistance and moldability, which is preferable.

The specific viscosity of the thermoplastic resin of the present invention is preferably 0.12 to 0.40, more preferably 0.15 to 0.35, and even more preferably 0.18 to 0.30. , 0.24 to 0.26 is most preferable. When the specific viscosity is within the above range, the moldability and the mechanical strength are well balanced, which is preferable.

The Abbe number (ν) of the thermoplastic resin of the present invention is preferably 17 to 25, and more preferably 17 to 23. The Abbe number is calculated from the refractive index at wavelengths of 486 nm, 589 nm and 656 nm measured at 25° C. using the following formula.
ν=(nD-1)/(nF-nC)
In the present invention,
nD: refractive index at a wavelength of 589 nm,
nC: refractive index at a wavelength of 656 nm,
nF: means a refractive index at a wavelength of 486 nm.

The absolute value of the orientation birefringence (Δn) of the thermoplastic resin of the present invention is preferably 0 to 4×10 ⁻³ , and more preferably 0 to 2×10 ⁻³ . The orientation birefringence (Δn) is measured at a wavelength of 589 nm when a cast film having a thickness of 100 μm obtained from the thermoplastic resin of the present invention is stretched 2 times at Tg+10° C. When the orientation birefringence is within the above range, the optical strain of the lens becomes small, which is preferable.
Δn=Re/d
Δn: orientation birefringence
Re: Phase difference (nm)
d: Thickness (nm)
The repeating unit of the general formula (1) can be produced by reacting a diol component described below with a dicarboxylic acid component.

Specific raw materials will be described below.
<Dicarboxylic Acid Component of General Formula (1)>
As the dicarboxylic acid component, a compound represented by the following formula (a) or an ester-forming derivative thereof is preferably used.

In the above general formula (a) of the dicarboxylic acid as the raw material of the general formula (1) of the present invention, R ¹ and R ² are each independently a hydrocarbon which may contain an aromatic group having 1 to 10 carbon atoms. And n and m each independently represent an integer of 0 or more. R ^{3 to} R ¹⁰ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. R ¹ and R ² preferably each independently represent a hydrocarbon group having 1 to 3 carbon atoms, and n and m preferably each independently represent an integer of 0 or 1. R ^{3 to} R ¹⁰ are preferably each independently a hydrogen atom or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. Particularly preferably, R ¹ and R ² represent a methylene group, n and m represent 1, and R ^{3 to} R ¹⁰ represent hydrogen atoms. Further, R ¹ and R ² may be the same or different, n and m may be the same or different, and R ^{3 to} R ¹⁰ may be the same or different. Is also good.

Hereinafter, typical specific examples of the dicarboxylic acid represented by the general formula (a) or an ester-forming derivative thereof will be shown. However, the raw material used in the general formula (1) of the present invention is not limited thereto. Absent.
2,2′-dicarboxy-1,1′-binaphthyl, 2,2′-bis(carboxymethoxy)-1,1′-binaphthyl, 2,2′-bis(2-carboxyethoxy)-1,1′ -Binaphthyl, 2,2'-bis(3-carboxypropoxy)-1,1'-binaphthyl, 2,2'-dimethoxycarbonyl-1,1'-binaphthyl, 2,2'-bis(methoxycarbonylmethoxy)- 1,1′-binaphthyl, 2,2′-bis(2-methoxycarbonylethoxy)-1,1′-binaphthyl, 2,2′-bis(3-methoxycarbonylpropoxy)-1,1′-binaphthyl, 2 ,2'-diethoxycarbonyl-1,1'-binaphthyl, 2,2'-bis(ethoxycarbonylmethoxy)-1,1'-binaphthyl, 2,2'-bis(2-ethoxycarbonylethoxy)-1, 1'-binaphthyl, 2,2'-bis(3-ethoxycarbonylpropoxy)-1,1'-binaphthyl, 2,2'-diphenoxycarbonyl-1,1'-binaphthyl, 2,2'-bis(phenoxy Carbonylmethoxy)-1,1′-binaphthyl, 2,2′-bis(2-phenoxycarbonylethoxy)-1,1′-binaphthyl, 2,2′-bis(3-phenoxycarbonylpropoxy)-1,1′ -Binaphthyl, 2,2'-ditert-butoxycarbonyl-1,1'-binaphthyl, 2,2'-bis(tert-butoxycarbonylmethoxy)-1,1'-binaphthyl, 2,2'-bis(2 -Tert-butoxycarbonylethoxy)-1,1'-binaphthyl, 2,2'-bis(3-tert-butoxycarbonylpropoxy)-1,1'-binaphthyl and the like can be mentioned. Among these, 2,1'-bis(carboxymethoxy) in which R ¹ and R ² in the general formula (a) are methylene groups, o and p are 1 and R ^{3 to} R ¹⁰ are hydrogen atoms Most preferred is -1,1'-binaphthyl (hereinafter sometimes abbreviated as BCMB) or an ester-forming derivative thereof.

<The diol component of the general formula (1)>
As the diol component, a compound mainly represented by the general formula (b) is preferably used.

In the general formula (b) of the diol component as the raw material of the general formula (1), R ¹¹ and R ¹² are each independently a hydrocarbon group which may contain an aromatic group having 1 to 10 carbon atoms. And o and p each independently represent an integer of 0 or more. R ¹³ and R ¹⁴ each independently represent a hydrocarbon group which may contain a hydrogen atom or an aromatic group having 1 to 20 carbon atoms. R ¹¹ and R ¹² preferably each independently represent a hydrocarbon group having 1 to 4 carbon atoms, and o and p each independently represent an integer of 0 or 1. Particularly preferably, R ¹¹ and R ¹² represent an ethylene group, o and p represent 1, and R ¹³ and R ¹⁴ represent a hydrogen atom or a phenyl group. Further, R ¹¹ and R ¹² may be the same or different, o and p may be the same or different, and R ¹³ and R ¹⁴ may be the same or different. May be.

Formula specifically ^(b), the a R ^{11, R 12} is an ethylene group, o and p are the ^{1, R 13,} R ¹⁴ is a hydrogen atom of 9,9-bis [4- ( 2-hydroxyethoxy)phenyl]fluorene (hereinafter sometimes abbreviated as BPEF) or 9,9-bis[4-(2-hydroxyethoxy)-3-phenyl in which R ¹³ and R ¹⁴ are phenyl groups. More preferably, it is phenyl]fluorene (hereinafter sometimes abbreviated as OPBPEF) or biscresolfluorene in which o and p are 0 and R ¹³ and R ¹⁴ are methyl groups.

<Copolymerization component other than general formula (1)>
The thermoplastic resin according to the present invention has the repeating unit represented by the general formula (1), but may further contain a copolymerization component. Examples of the copolymerization component include dicarboxylic acid components other than those represented by the general formula (a), diol components other than those represented by the general formula (b), and repeating units having a carbonate bond.

Specific examples of the dicarboxylic acid component as a copolymerization component include malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, methylmalonic acid, ethylmalonic acid, and other aliphatic dicarboxylic acid components, Monocyclic aromatic dicarboxylic acid components such as phthalic acid, isophthalic acid and terephthalic acid, 2,7-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,8-naphthalenedicarboxylic acid , Polycyclic aromatic dicarboxylic acid components such as anthracene dicarboxylic acid and phenanthrene dicarboxylic acid, biphenyl dicarboxylic acid components such as 2,2′-biphenyldicarboxylic acid, 1,4-cyclodicarboxylic acid, 2,6-decalindicarboxylic acid, etc. Alicyclic dicarboxylic acid component of. You may use these individually or in combination of 2 or more types. Moreover, you may use acid chloride and ester as these derivatives. Among these, a monocyclic aromatic dicarboxylic acid component, a polycyclic aromatic dicarboxylic acid component, and a biphenyl dicarboxylic acid component are preferable because they are likely to have higher heat resistance and a higher refractive index.

Specific examples of the diol component as a copolymerization component include aliphatic diol components such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol and nonanediol, and tricyclo[5.2]. 1.02,6] Decanedimethanol, cyclohexane-1,4-dimethanol, decalin-2,6-dimethanol, norbornanedimethanol, pentacyclopentadecanedimethanol, cyclopentane-1,3-dimethanol, spiro Alicyclic diol components such as glycol and isosorbide, hydroquinone, resorcinol, 2,2-bis(4-hydroxyphenyl)propane, 2,2-bis(3-methyl-4-hydroxyphenyl)propane, 1,1-bis (4-hydroxyphenyl)-1-phenylethane, bis(4-hydroxyphenyl)diphenylmethane, 1,3-bis(2-(4-hydroxyphenyl)-2-propyl)benzene, bis(4-hydroxyphenyl)sulfone , Bis(4-(2-hydroxyethoxy)phenyl)sulfone, bis(4-hydroxyphenyl)sulfide, 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane, 1,1-bis (4-hydroxyphenyl)cyclohexane, biphenol, 2,2'-bis(2-hydroxyethoxy)-1,1'-binaphthyl, 1,1'-bi-2-naphthol, dihydroxynaphthalene, bis(2-hydroxyethoxy) ) Aromatic diol components such as naphthalene and 10,10-bis(4-hydroxyphenyl)anthrone are listed. You may use these individually or in combination of 2 or more types. Among these, ethylene glycol and 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthyl are preferable because they can easily suppress the deterioration of heat resistance and refractive index while improving the moldability.

Specific examples of the repeating unit having a carbonate bond as a copolymerization component include those in which the diol component exemplified in the general formula (b) and the diol component exemplified as the above-mentioned copolymerization component are carbonate-bonded. Among these, since it is easy to suppress deterioration of heat resistance and refractive index while enhancing moldability, the diol component and 2,2′-bis(2-hydroxyethoxy)-1,2' exemplified in the above general formula (b) are Those using 1'-binaphthyl are preferable.

The thermoplastic resin of the present invention undergoes an esterification reaction or a transesterification reaction of the raw materials represented by the general formulas (a) and (b) described above, and the obtained reaction product is subjected to a polycondensation reaction to obtain a desired high molecular weight compound. It may be a molecular weight substance.

Specifically, for example, it is preferable to mix the diol component and the dicarboxylic acid component or its diester in the presence of an inert gas, and to react under reduced pressure usually at 120 to 350°C, preferably at 150 to 300°C. .. The degree of pressure reduction is changed stepwise, and finally water or alcohols generated at 0.13 kPa or less is distilled out of the system, and the reaction time is usually about 1 to 10 hours.

As the polymerization catalyst, those known per se can be adopted, and for example, antimony compounds, titanium compounds, germanium compounds, tin compounds or aluminum compounds are preferable. Examples of such compounds include antimony, titanium, germanium, tin, aluminum oxides, acetates, carboxylates, hydrides, alcoholates, halides, carbonates and sulfates. Moreover, these compounds can be used in combination of 2 or more types. Among these, tin, titanium and germanium compounds are preferable from the viewpoints of melt stability and hue of the thermoplastic resin.

As the transesterification catalyst, one known per se can be adopted, and for example, a compound containing manganese, magnesium, titanium, zinc, aluminum, calcium, cobalt, sodium, lithium, or lead element can be used. Specific examples include oxides containing these elements, acetates, carboxylates, hydrides, alcoholates, halides, carbonates, sulfates and the like. Among these, compounds such as manganese, magnesium, zinc, titanium, cobalt oxides, acetates, and alcoholates are preferable from the viewpoints of the melt stability of the thermoplastic resin, the hue, and the small amount of polymer-insoluble foreign matter. Further, manganese, magnesium and titanium compounds are preferable. These compounds can be used in combination of two or more kinds.

The thermoplastic resin of the present invention may contain a copolymerization component other than the repeating unit of the general formula (1) as described above. For example, in the case of using a polyester carbonate resin, it can be produced by reacting with a dicarboxylic acid chloride or phosgene in addition to a diol component and a dicarboxylic acid component, or by reacting a diol, a dicarboxylic acid and a biaryl carbonate.

Specific examples of the biaryl carbonate include carbonic acid diesters such as diphenyl carbonate, di-p-tolyl carbonate, phenyl-p-tolyl carbonate, di-p-chlorophenyl carbonate, and dinaphthyl carbonate. Of these, diphenyl carbonate is preferred.

The content of the dicarboxylic acid chloride, phosgene, or biaryl carbonate component is preferably less than 42 mol%, more preferably less than 30 mol%, and further preferably less than 20 mol% with respect to 100 mol% of the dicarboxylic acid component.

<Additive>
To the thermoplastic resin of the present invention, if necessary, additives such as a heat stabilizer, an antioxidant, a release agent, a plasticizer, a filler, and an ultraviolet absorber are appropriately added to obtain a thermoplastic resin composition. Can be used.

As the release agent, those having 90% by weight or more thereof consisting of alcohol and fatty acid ester are preferable. Specific examples of the ester of alcohol and fatty acid include esters of monohydric alcohol and fatty acid and/or partial or total ester of polyhydric alcohol and fatty acid. The ester of monohydric alcohol and fatty acid is preferably an ester of monohydric alcohol having 1 to 20 carbon atoms and saturated fatty acid having 10 to 30 carbon atoms. The partial ester or total ester of polyhydric alcohol and fatty acid is preferably a partial ester or total ester of polyhydric alcohol having 1 to 25 carbon atoms and saturated fatty acid having 10 to 30 carbon atoms. Specific examples of monohydric alcohols, saturated fatty acids and esters include stearyl stearate, palmityl palmitate, butyl stearate, methyl laurate, isopropyl palmitate and the like, with stearyl stearate being preferred.

Specific examples of the partial or total ester of a polyhydric alcohol and a saturated fatty acid include stearic acid monoglyceride, stearic acid diglyceride, stearic acid triglyceride, stearic acid monosorbate, behenic acid monoglyceride, pentaerythritol monostearate, pentaerythritol tetraglyceride. All or partial ester of dipentaerythritol such as stearate, pentaerythritol tetrapelargonate, propylene glycol monostearate, biphenyl biphenate, sorbitan monostearate, 2-ethylhexyl stearate, dipentaerythritol hexastearate Examples thereof include esters. Among these esters, stearic acid monoglyceride, stearic acid triglyceride, pentaerythritol tetrastearate, and a mixture of stearic acid triglyceride and stearyl stearate are preferably used.

The amount of the ester in the release agent is preferably 90% by weight or more, more preferably 95% by weight or more, based on 100% by weight of the release agent.

The release agent to be added to the thermoplastic resin composition is preferably in the range of 0.005 to 2.0 parts by weight, more preferably 0.01 to 0.6 parts by weight, based on 100 parts by weight of the thermoplastic resin. The range of 0.02 to 0.5 parts by weight is preferable, and the range is more preferable.

Examples of the heat stabilizer include phosphorus-based heat stabilizers, sulfur-based heat stabilizers and hindered phenol-based heat stabilizers.

In the phosphorus-based heat stabilizer, tetrakis(2,4-di-tert-butylphenyl)-4,4'-biphenylene diphosphonite is preferably used.

The content of the phosphorus-based heat stabilizer in the thermoplastic resin is preferably 0.001 to 0.2 parts by weight with respect to 100 parts by weight of the thermoplastic resin.

In the hindered phenol heat stabilizer, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate is particularly preferably used.

The content of the hindered phenolic heat stabilizer in the thermoplastic resin is preferably 0.001 to 0.3 parts by weight based on 100 parts by weight of the thermoplastic resin.

As the UV absorber, at least one UV absorber selected from the group consisting of benzotriazole UV absorbers, benzophenone UV absorbers, triazine UV absorbers, cyclic iminoester UV absorbers and cyanoacrylate UV absorbers. Is preferred.

In the benzotriazole type ultraviolet absorber, more preferably, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2,2′-methylenebis[4-(1,1,3,3-tetramethyl) Butyl)-6-(2H-benzotriazol-2-yl)phenol].
Examples of the benzophenone-based ultraviolet absorber include 2-hydroxy-4-n-dodecyloxybenzophenone and 2-hydroxy-4-methoxy-2'-carboxybenzophenone.
Examples of the triazine-based ultraviolet absorber include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol and 2-(4,6-bis( 2.4-Dimethylphenyl)-1,3,5-triazin-2-yl)-5-[(octyl)oxy]-phenol and the like can be mentioned.
As the cyclic iminoester-based ultraviolet absorber, 2,2'-p-phenylenebis(3,1-benzoxazin-4-one) is particularly preferable.

The blending amount of the ultraviolet absorber is preferably 0.01 to 3.0 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the blending amount is within the above range, a thermoplastic resin molded article can be obtained depending on the application. It is possible to impart sufficient weather resistance.
<Optical lens>
The thermoplastic resin of the present invention is suitable for optical members, especially optical lenses.

When the optical lens of the thermoplastic resin of the present invention is manufactured by injection molding, it is preferable to mold under the conditions of a cylinder temperature of 260 to 350°C and a mold temperature of 90 to 170°C. More preferably, the molding is performed under the conditions of a cylinder temperature of 270 to 320° C. and a mold temperature of 100 to 160° C. When the cylinder temperature is higher than 350°C, the thermoplastic resin is decomposed and colored, and when it is lower than 260°C, the melt viscosity is high and molding tends to be difficult. Further, if the mold temperature is higher than 170° C., it tends to be difficult to take out the molded piece made of the thermoplastic resin from the mold. On the other hand, if the mold temperature is lower than 90° C., the resin may harden too quickly in the mold during molding, making it difficult to control the shape of the molded piece, or sufficiently transferring the mold attached to the mold. Is likely to be difficult.

The optical lens of the present invention is preferably implemented in the form of an aspherical lens, if necessary. Since an aspherical lens can reduce the spherical aberration to substantially zero with one lens, it is not necessary to remove the spherical aberration by combining a plurality of spherical lenses, and it is possible to reduce the weight and the molding cost. It will be possible. Therefore, the aspherical lens is particularly useful as a camera lens among optical lenses.

Further, since the optical lens of the present invention has high molding fluidity, it is particularly useful as a material for an optical lens that is thin and small and has a complicated shape. As a specific lens size, the thickness of the central portion is 0.05 to 3.0 mm, more preferably 0.05 to 2.0 mm, and further preferably 0.1 to 2.0 mm. The diameter is 1.0 mm to 20.0 mm, more preferably 1.0 to 10.0 mm, and further preferably 3.0 to 10.0 mm. Further, it is preferable that the meniscus lens has a convex shape on one side and a concave shape on one side.

The lens made of the thermoplastic resin in the optical lens of the present invention is molded by any method such as mold molding, cutting, polishing, laser machining, electric discharge machining, and etching. Among these, die molding is more preferable from the viewpoint of manufacturing cost.

The present invention will be further described below with reference to examples, but the present invention is not limited thereto. The evaluation was performed by the following method.

(A) Film 3 g of the obtained thermoplastic resin was dissolved in 50 ml of methylene chloride and cast on a glass petri dish. After being sufficiently dried at room temperature, it was dried at a temperature of 120° C. for 24 hours to prepare a cast film having a thickness of about 100 μm.

The evaluation was performed by the following method.
(1) Copolymerization ratio: The thermoplastic resin thus obtained was measured by using proton NMR of JNM-AL400 manufactured by JEOL Ltd.
(2) Specific viscosity: The obtained thermoplastic resin was sufficiently dried, and the specific viscosity (η _sp ) of the solution at 20° C. was measured from a solution prepared by dissolving 0.7 g of the resin in 100 ml of methylene chloride.
(3) Glass transition point: The thermoplastic resin thus obtained was measured by DSC-60A manufactured by Shimadzu at a heating rate of 20° C./min.
(4) Refractive index (nd): The film prepared by the method of (a) was measured for the refractive index (wavelength: 589 nm) at 25° C. using an Abbe refractometer of DR-M2 manufactured by ATAGO.
(5) Orientation birefringence (Δn): A cast film having a thickness of 100 μm prepared by the method of (a) was stretched 2 times at Tg+10° C., and the position at 589 nm was measured using an ellipsometer M-220 manufactured by JASCO Corporation. The phase difference (Re) was measured, and the orientation birefringence (Δn) was calculated from the following formula.
Δn=Re/d
Δn: orientation birefringence
Re: Phase difference (nm)
d: Thickness (nm)
◯: 0 or more, 2×10 ⁻³ or less Δ: 2×10 ^{−3 or} more, 4×10 ⁻³ or less ×: 4×10 ^{−3 or} more

Example 1
2,2'-bis(carboxymethoxy)-1,1'-binaphthyl (BCMB) 16.90 parts by weight, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (BPEF) 25.43 parts by weight Parts, 3.64 parts by weight of diphenyl carbonate (DPC) and 17.0×10 ⁻³ parts by weight of tetrabutoxytitanium in a reaction kettle equipped with a stirrer and a distillation device, and heated to 180° C. under a nitrogen atmosphere and atmospheric pressure, Stir for 20 minutes. Then, the temperature was gradually raised and the pressure was reduced, and the temperature was raised to 260° C. and 0.13 kPa or less and the pressure was reduced to carry out the transesterification/polycondensation reaction. After reaching a predetermined stirring torque, the content was taken out of the reactor to obtain polyester carbonate resin pellets. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester carbonate resin was introduced into the polyester carbonate resin in an amount of 42 mol% with respect to the total monomer components (total dicarboxylic acid component+total diol component). The diol component was 58 mol% with respect to all the monomer components (all dicarboxylic acid components + all diol components). The polyester carbonate resin obtained had a specific viscosity of 0.24, a glass transition temperature Tg of 150° C., and a refractive index of 1.660.

Example 2
Polymerization was carried out in the same manner as in Example 1 except that BCMB was 20.12 parts by weight, BPEF was 21.93 parts by weight, and DPC was 0 parts by weight. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester resin was 50 mol% with respect to the total monomer components (total dicarboxylic acid component + total diol component), and the diol component introduced into the polyester resin was It was 50 mol% with respect to all monomer components (all dicarboxylic acid components + all diol components). The polyester resin obtained had a specific viscosity of 0.25, a glass transition temperature Tg of 150° C., and a refractive index of 1.664.

Example 3
Polymerization was performed in the same manner as in Example 1 except that BCMB was 20.12 parts by weight, BPEF was 17.54 parts by weight, DPC was 0 part by weight, and ethylene glycol (EG) was 3.72 parts by weight. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester resin was 50 mol% with respect to the total monomer components (total dicarboxylic acid component + total diol component), and the diol component introduced into the polyester resin was It was 50 mol% with respect to all monomer components (all dicarboxylic acid components+all diol components), 40 mol% was derived from BPEF, and 10 mol% was derived from EG. The polyester resin thus obtained had a specific viscosity of 0.24, a glass transition temperature Tg of 145° C. and a refractive index of 1.665.

Example 4
Example 1 except that BCMB 16.90 parts by weight, 9,9-bis[4-(2-hydroxyethoxy)-3-phenylphenyl]fluorene (OPBPEF) 34.26 parts by weight, and DPC 3.64 parts by weight. It polymerized similarly. When the obtained pellets were analyzed by NMR, the diol acid component introduced into the polyester carbonate resin was 58 mol% with respect to the total monomer components (total dicarboxylic acid component+total diol component), and the dicarboxylic acid introduced into the polyester carbonate resin was The content of the components was 42 mol% with respect to all the monomer components (all dicarboxylic acid components + all diol components). Moreover, the specific viscosity of the obtained polyester carbonate resin was 0.26, the glass transition temperature Tg was 153° C., and the refractive index was 1.668.

Example 5
Polymerization was carried out in the same manner as in Example 1 except that BCMB was 20.12 parts by weight, OPBPEF was 29.54 parts by weight, and DPC was 0 parts by weight. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester resin was 50 mol% with respect to the total monomer components (total dicarboxylic acid component + total diol component), and the diol component introduced into the polyester resin was It was 50 mol% with respect to all monomer components (all dicarboxylic acid components + all diol components). Moreover, the specific viscosity of the obtained polyester resin was 0.26, the glass transition temperature Tg was 153° C., and the refractive index was 1.671.

Example 6
Polymerization was performed in the same manner as in Example 1 except that BCMB was 20.12 parts by weight, BHEB was 23.63 parts by weight, DPC was 0 part by weight, and ethylene glycol (EG) was 3.72 parts by weight. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester resin was 50 mol% with respect to the total monomer components (total dicarboxylic acid component + total diol component), and the diol component introduced into the polyester resin was It was 50 mol% with respect to all monomer components (all dicarboxylic acid components+all diol components), 40 mol% was derived from OPBPEF, and 10 mol% was derived from EG. The polyester resin obtained had a specific viscosity of 0.26, a glass transition temperature Tg of 149° C., and a refractive index of 1.671.

Example 7
Polymerization was performed in the same manner as in Example 1 except that 2,2′-bis(ethoxycarbonylmethoxy)-1,1′-binaphthyl (BECMB) was 22.93 parts by weight, BPEF was 21.93 parts by weight, and DPC was 0 parts by weight. When the obtained pellets were analyzed by NMR, the diester component introduced into the polyester resin was 50 mol% with respect to the total monomer components (all diester components + all diol components), and the diol component introduced into the polyester resin was all monomers. It was 50 mol% with respect to the components (all diester components + all diol components). The polyester resin obtained had a specific viscosity of 0.25, a glass transition temperature Tg of 150° C., and a refractive index of 1.664.

Comparative Example 1
As in Example 1, except that BCMB was 20.12 parts by weight, 2,2′-bis(2-hydroxyethoxy)-1,1′-binaphthyl (BHEB) was 11.23 parts by weight, and EG was 4.34 parts by weight. Polymerized. When the obtained pellets were analyzed by NMR, it was found that the dicarboxylic acid component introduced into the polyester resin was 50 mol% with respect to the total monomer components (total dicarboxylic acid component + total diol component), and the diol component introduced into the polyester resin was The content was 50 mol%, 30 mol% was derived from BHEB, and 20 mol% was derived from EG with respect to all monomer components (all dicarboxylic acid components+all diol components). The specific viscosity of the obtained polyester resin was 0.27, the glass transition temperature Tg was 128° C., and the refractive index was 1.677.

Comparative example 2
Polymerization was performed in the same manner as in Example 1 except that dimethyl terephthalate (DMT) was 9.71 parts by weight, BHEB was 18.72 parts by weight, and diphenyl carbonate (DPC) was 0 parts by weight. When the obtained pellets were analyzed by NMR, the diester component introduced into the polyester resin was 50 mol% with respect to the total monomer components (all diester components + all diol components), and the diol component introduced into the polyester resin was all monomers. It was 50 mol% with respect to the components (all diester components + all diol components). The polyester resin obtained had a specific viscosity of 0.25, a glass transition temperature Tg of 127° C., and a refractive index of 1.658.

Comparative Example 3
Polymerization was performed in the same manner as in Example 1 except that 21.93 parts by weight of BPEF, 18.72 parts by weight of BHEB, and 21.85 parts by weight of DPC. When the obtained pellets were analyzed by NMR, it was found that 50 mol% was derived from BPEF and 50 mol% was derived from BHEB with respect to all the monomer components introduced into the polycarbonate resin. The specific viscosity of the obtained polycarbonate resin was 0.23, the glass transition temperature Tg was 135° C., and the refractive index was 1.649.

Comparative Example 4
Polymerization was carried out in the same manner as in Example 1 except that 43.85 parts by weight of BPEF and 21.85 parts by weight of DPC were used. When the obtained pellets were analyzed by NMR, 100 mol% of the diol component introduced into the polycarbonate resin was derived from BPEF. The specific viscosity of the obtained polycarbonate resin was 0.24, the glass transition temperature Tg was 147° C., and the refractive index was 1.638.

The value of the formula (1) in Table 1 is the ratio of the repeating unit represented by the formula (1) when the total of all the repeating units is 100 mol %.

The polyester or polyester carbonate resin obtained in Examples 1 to 7 in Table 1 is a resin having high refractive index, low birefringence and high heat resistance, and is excellent as an optical lens. On the other hand, the polymer of Comparative Example 1 has low heat resistance, and Comparative Example 2 has insufficient birefringence and has poor heat resistance. Further, Comparative Example 3 is a polycarbonate copolymer in which the 1,1'-binaphthyl structure is used as the diol component BHEB and is copolymerized with BPEF, but the refractive index is low.

The thermoplastic resin of the present invention has a high refractive index, a low birefringence, and a high heat resistance. It can be used as an optical member such as a filter and a hard coat film, and is particularly useful for a lens.

Claims (12)

A thermoplastic resin in which the repeating unit represented by the following general formula (1) contains 70 mol% or more of all the units.
(In the formula (1), R ¹ and R ² each independently represent a hydrocarbon group which may contain an aromatic group having 1 to 10 carbon atoms, and n and m each independently represent an integer of 0 or more. R ^{3 to} R ¹⁰ each independently represent a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a hydrocarbon group which may contain an aromatic group having 1 to 12 carbon atoms. .R ¹¹ and ^{R 12} are each independently represents an even better hydrocarbon group include an aromatic group having 1 to 10 carbon atoms, o and p is an integer of 0 or more each independently ^{.R 13} And R ¹⁴ each independently represents a hydrogen atom or a hydrocarbon group which may contain an aromatic group having 1 to 20 carbon atoms.) In the general formula (1), R ¹ and R ² are each a hydrocarbon group having 1 to 3 carbon atoms, n and m are each 0 or 1, and R ^{3 to} R ¹⁰ are each hydrogen. The thermoplastic resin according to claim 1, which is a hydrocarbon group which may contain an atom or an aromatic group having 1 to 12 carbon atoms. The thermoplastic resin according to claim 2, wherein in the general formula (1), R ¹ and R ² are each a methylene group, n and m are each 1, and R ^{3 to} R ¹⁰ are hydrogen atoms. .. In the general formula (1), R ¹¹ and R ¹² are each a hydrocarbon group having 1 to 4 carbon atoms, o and p are each 0 or 1, and R ¹³ and R ¹⁴ are each hydrogen. The thermoplastic resin according to claim 1, which is a hydrocarbon group which may contain an atom or an aromatic group having 1 to 12 carbon atoms. In the general formula (1), R ¹¹ and R ¹² are each an ethylene group, o and p are each 1, and R ¹³ and R ¹⁴ are each a hydrogen atom or a phenyl group. The thermoplastic resin according to. The thermoplastic resin according to any one of claims 1 to 5 , which has a refractive index of 1.650 to 1.700. The thermoplastic resin according to the specific viscosity is any one of claims 1 to 6 which is 0.12 to 0.40. The thermoplastic resin according to any one of claims 1 to 8, which has a glass transition temperature of 128 to 160°C. The thermoplastic resin according to any one of claims 1-8 orientation birefringence is 0 to 4 × ^{10 -3.} 10. The thermoplastic resin according to claim 1, which is a polyester or polyester carbonate resin. An optical member comprising the thermoplastic resin according to claim 1. An optical lens made of the thermoplastic resin according to claim 1.