JP2023139355A - Thermoplastic resin, optical member composed of the same, and diol compound - Google Patents

Abstract

To provide a thermoplastic resin using a new diol compound, having an appropriate refractive index and an Abbe number, and having a low water absorption rate, and an optical member including the same.SOLUTION: A thermoplastic resin includes a structural unit represented by the following formula (1). In the formula (1), R1 and R2 each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R3 and R4 each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. In addition, R1 and R3, or R2 or R4 may be bonded to each other and form a ring. W is a residue obtained by removing a hydroxyl group from a carbonic acid or a dicarboxylic acid.SELECTED DRAWING: None

Description

The present invention relates to a thermoplastic resin that uses a novel diol compound, has an appropriate refractive index and Abbe number, and has a low water absorption rate, and an optical member made from the thermoplastic resin.

Imaging modules are used in cameras, video cameras, mobile phones with cameras, videophones, doorbells with cameras, and the like. In recent years, there has been a particular demand for miniaturization of optical systems used in imaging modules. As optical systems become smaller, chromatic aberration in the optical system becomes a major problem. Therefore, by combining an optical lens material that has a high refractive index and a small Abbe number to achieve high dispersion, and an optical lens material that has a low refractive index and a large Abbe number to achieve low dispersion, it is possible to reduce chromatic aberration. It is known that it is possible to perform corrections for

In recent years, the types of optical elements used in photographic modules have increased, and there has been a strong demand for resins for optical lenses having variously balanced refractive indexes and Abbe numbers. However, regarding optical lens materials that have low refractive index and large Abbe number to achieve low dispersion, there are few reports on thermoplastic resins that are well-balanced with heat resistance.

In addition, in recent years, due to concerns about the depletion of petroleum resources and the problem of increasing carbon dioxide in the air, which causes global warming, carbon neutrality is becoming a reality, which does not rely on petroleum as a raw material and does not increase carbon dioxide even when burned. Biomass resources are attracting a lot of attention, and in the field of polymers, biomass plastics produced from biomass resources are being actively developed. In particular, polycarbonate mainly using isosorbide as a monomer has been attracting attention because it has excellent heat resistance, weather resistance, surface hardness, and chemical resistance, and has different characteristics from polycarbonate made of general bisphenol A. has been studied (Patent Documents 1 and 2). Regarding optical properties, it has been reported that the refractive index is low and the Abbe number is large. (Patent Document 3). Although these isosorbide polycarbonates have excellent characteristics, they have a problem of high water absorption. Therefore, when used as an optical lens material, it is not possible to increase the isosorbide copolymerization ratio, and the characteristics of isosorbide cannot be fully utilized as a bioplastic.

Japanese Patent Application Publication No. 2006-36954 Japanese Patent Application Publication No. 2009-46519 International Publication No. 2012/144573

An object of the present invention is to provide a thermoplastic resin that uses a novel diol compound, has an appropriate refractive index and Abbe number, and has a low water absorption rate, and an optical member containing the same.
Further, a preferable object of the present invention is to provide a thermoplastic resin with a high degree of biomass and an optical member containing the same, using a novel diol compound synthesized from raw materials not derived from petroleum.

The present inventors have conducted extensive research to achieve this objective, and as a result, have discovered that a thermoplastic resin having a specific structure can solve the above-mentioned problems, and have arrived at the present invention. That is, the present invention is as follows (Aspect 1) to (Aspect 17).

(Aspect 1)
A thermoplastic resin containing a structural unit represented by the following formula (1).

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring. W is at least one selected from the group consisting of the following formula (2) and the following formula (3). .)

(In the formula, X represents a divalent linking group.)

(Aspect 2)
The thermoplastic resin according to aspect 1, wherein the structural unit represented by the formula (1) accounts for 5 mol% to 100 mol% of all structural units constituting the thermoplastic resin.
(Aspect 3)
The thermoplastic resin according to aspect 1 or 2, wherein R ¹ and R ² in the formula (1) are methyl groups.
(Aspect 4)
The thermoplastic resin according to any one of aspects 1 to 3, wherein R ³ and R ⁴ in the formula (1) are methylene groups.
(Aspect 5)
The thermoplastic resin according to any one of aspects 1 to 4, further comprising a structural unit represented by the following formula (4).

(In formula (4), R ⁵ and R ⁶ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and L ¹ and L ² each independently represent a divalent linking group. (m and n each independently represent 0 or 1.)

(Aspect 6)
The thermoplastic resin according to any one of aspects 1 to 5, wherein in the formula (1), W is the formula (2).
(Aspect 7)
The thermoplastic resin according to any one of aspects 1 to 6, which has a water absorption rate of 0.25% or less after immersion at 23° C. for 24 hours.
(Aspect 8)
The thermoplastic resin according to any one of aspects 1 to 7, having a biomass degree of 5% or more.
(Aspect 9)
The thermoplastic resin according to any one of aspects 1 to 8, having a 5% weight loss temperature of 350° C. or higher.
(Aspect 10)
The thermoplastic resin according to any one of aspects 1 to 9, having a refractive index of 1.450 to 1.650.
(Aspect 11)
The thermoplastic resin according to any one of aspects 1 to 10, having an Abbe number of 20 to 65.
(Aspect 12)
An optical member formed from the thermoplastic resin according to any one of aspects 1 to 11.
(Aspect 13)
The optical member according to aspect 12, which is an optical lens.
(Aspect 14)
A diol compound represented by the following formula (a).

(In formula (a), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring.)

(Aspect 15)
The diol compound according to aspect 14, wherein R ¹ and R ² in the formula (a) are methyl groups.
(Aspect 16)
The diol compound according to aspect 14 or 15, wherein R ³ and R ⁴ in the formula (a) are methylene groups.
(Aspect 17)
The method for producing a diol compound according to aspect 14, wherein hydroxyketones represented by the following formula (5) and erythritol represented by the following formula (6) are subjected to a cyclodehydration reaction in the presence of an acid catalyst and a solvent.

(In formula (5), R ⁷ represents a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁸ represents a hydrogen atom having 1 to 10 carbon atoms. It represents 10 divalent acyclic hydrocarbon groups or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁷ and R ⁸ may be bonded to each other to form a ring. )

The thermoplastic resin of the present invention has excellent optical properties and low water absorption, so it can be used for optical lenses, prisms, optical disks, transparent conductive substrates, optical cards, sheets, films, optical fibers, optical films, optical filters, hard coat films, etc. It is particularly useful for optical lenses for use in mobile phones, smartphones, tablet terminals, personal computers, digital cameras, video cameras, in-vehicle cameras, or surveillance cameras. The effect is exceptional.

¹ H NMR of 2,6-bis(hydroxymethyl)-2,6-dimethyl-1,3,5,7-tetraoxadecalin obtained in Example 1. ¹ H NMR of the polycarbonate resin obtained in Example 2. ^1H NMR of the polycarbonate resin obtained in Example 3. ^1H NMR of the polycarbonate resin obtained in Example 4. 1 is a graph of changes in water absorption rates in Examples 2 to 4 and Comparative Examples 1 to 2.

The present invention will be explained in more detail.
<Thermoplastic resin>
The thermoplastic resin of the present invention is a thermoplastic resin containing a structural unit represented by the following formula (1).

(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring. W is at least one selected from the group consisting of the following formula (2) and the following formula (3). .)

(In the formula, X represents a divalent linking group.)
In the formula (1), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and a hydrogen atom Alternatively, an acyclic hydrocarbon group having 1 to 3 carbon atoms is preferable, a hydrogen atom or a methyl group is more preferable, and a methyl group is even more preferable.

In the formula (1), R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. , a divalent acyclic hydrocarbon group having 1 to 3 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 6 carbon atoms are preferred, and a methylene group is more preferred.

In the above formula (1), R ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring, and as an example of the structure, preferably the following structural formula (1-a) Among them, from the viewpoint of heat resistance, it is particularly preferable that the ring structure is cyclohexane.

(In formula (1-a), L represents a divalent linking group, and k each independently represents 0 or 1.)
In the formula (1-a), L represents a divalent linking group, preferably an alkylene group having 1 to 4 carbon atoms, more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

In the above formula (1), W is at least one selected from the group consisting of the above formula (2) and the above formula (3), and the above formula (2) is preferable. When W is the formula (2), the formula (1) is a carbonate unit, and when W is the formula (3), the formula (1) is an ester unit.

The formula (1) can be obtained from a dihydroxy compound and a carbonate precursor such as a carbonate ester, or a dihydroxy compound and a dicarboxylic acid or an ester-forming derivative thereof.

In the thermoplastic resin containing the structural unit represented by the formula (1) in the present invention, the structural unit represented by the formula (1) is contained in an amount of 5 mol% or more and 10 mol% of all the structural units constituting the thermoplastic resin. As mentioned above, it may be contained in an amount of 15 mol% or more, 20 mol% or more, or 100 mol% or less, 90 mol% or less, 80 mol% or less, 70 mol% or less, 60 mol% or less, 50 mol% or less, or 40 mol% or less. In the thermoplastic resin of the present invention, the structural unit represented by the formula (1) is preferably 5 mol% or more and 100 mol% or less, more preferably 10 mol% or more and 80 mol% or less of all the structural units constituting the thermoplastic resin. , more preferably 15 mol% or more and 60 mol% or less, particularly preferably 20 mol% or more and 50 mol% or less. It is preferable that the ratio of the structural unit represented by the formula (1) is within the above range because it has an appropriate refractive index and Abbe number, has a low water absorption rate, and has a high ratio of raw materials not derived from petroleum resources. .

The thermoplastic resin of the present invention may further contain a structural unit represented by the following formula (4).

(In formula (4), R ⁵ and R ⁶ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and L ¹ and L ² each independently represent a divalent linking group. (m and n each independently represent 0 or 1.)

In the formula (4), R ⁵ and R ⁶ each independently represent a substituent having 1 to 20 carbon atoms which may include a hydrogen atom, a halogen atom, an aromatic group, and a hydrogen atom, a methyl group, a phenyl group. or a naphthyl group, more preferably a hydrogen atom, a methyl group or a phenyl group, even more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

In the formula (4), L ¹ and L ² each independently represent a divalent linking group, preferably an alkylene group having 1 to 12 carbon atoms, and more preferably an alkylene group having 1 to 4 carbon atoms. , more preferably an ethylene group. The glass transition temperature (Tg) of the resin can be adjusted by adjusting the length of the linking groups L ¹ and L ² .

<Physical properties of thermoplastic resin>
The water absorption rate of the thermoplastic resin of the present invention after immersion at 23°C for 24 hours is preferably 0.25% or less, more preferably 0.20% or less, and 0.18% or less. and even more preferable. Further, the water absorption rate after immersion at 23° C. for 480 hours is preferably 0.60% or less, more preferably 0.50% or less, and even more preferably 0.45% or less. When the water absorption rate is higher than the upper limit, dimensional changes in the shape due to moisture absorption and desorption become large. In particular, when molded into a lens or the like, expansion/contraction and changes in refractive index may occur, resulting in deterioration of lens performance such as focal length and wavefront aberration.

The biomass degree of the thermoplastic resin of the present invention is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, and particularly preferably 20% or more.

In the present invention, the degree of biomass in a thermoplastic resin is defined as the weight ratio of structural units synthesized from plant-derived resources among all structural units constituting the thermoplastic resin. Note that the degree of biomass in the thermoplastic resin does not need to be 100%. This is because if biomass-derived raw materials are used even in part, the purpose of the present invention is to reduce the amount of fossil fuel used and the environmental load. Further, whether or not the product is manufactured from plant-derived resources can be confirmed by, for example, measuring the concentration of radioactive carbon ( ¹⁴ C). Since atmospheric carbon dioxide contains ¹⁴ C at a certain rate (105.5 pMC), ^{the 14} C content in plants that grow by taking in atmospheric carbon dioxide, such as corn, is also around 105.5 pMC. It is known that It is also known that fossil fuels contain almost no ^14C . Therefore, by measuring the proportion of ¹⁴ C contained in all carbon atoms in the thermoplastic resin, the proportion of carbon derived from biomass can be calculated.

The number average molecular weight of the thermoplastic resin of the present invention is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 7,500 or more, and particularly preferably 10,000 or more. . It is preferable that the number average molecular weight is within the above range because it provides an excellent balance between moldability and mechanical strength.

The weight average molecular weight of the thermoplastic resin of the present invention is preferably 7,500 or more, more preferably 10,000 or more, even more preferably 20,000 or more, and particularly preferably 30,000 or more. . It is preferable that the weight average molecular weight is within the above range because it provides an excellent balance between moldability and mechanical strength.

The 5% weight loss temperature of the thermoplastic resin of the present invention is the 5% weight loss temperature at a heating rate of 20°C/min in a nitrogen atmosphere, preferably 350°C or higher, and preferably 360°C or higher. The temperature is more preferably 370°C or higher, even more preferably 380°C or higher. When the 5% weight loss temperature is equal to or higher than the above lower limit, heat resistance stability is high.

The refractive index of the thermoplastic resin of the present invention is 1.450 or more, 1.460 or more, 1.470 or more, 1.480 or more, 1.490 when measured at a temperature of 20°C and a wavelength of 587.56 nm. or more, or 1.500 or more, or 1.650 or less, 1.640 or less, 1.630 or less, 1.620 or less, 1.610 or less, or 1.600 or less.

The refractive index of the thermoplastic resin of the present invention is preferably in the range of 1.450 to 1.650, more preferably in the range of 1.460 to 1.640, and more preferably in the range of 1.470 to 1.630. More preferably, it is in the range of 1.480 to 1.620, most preferably in the range of 1.490 to 1.610.

The Abbe number of the thermoplastic resin of the present invention may be 20 or more, 21 or more, 22 or more, 23 or more, 24 or more, or 25 or more, 65 or less, 64 or less, 63 or less, 62 or less, 61 or less, 60 It may be less than or equal to 59. The Abbe number (νd) is preferably in the range of 20 to 65, more preferably in the range of 22 to 63, even more preferably in the range of 25 to 60.

Here, the Abbe number is calculated from the refractive index at temperature: 20°C and wavelength: 486.13 nm, 587.56 nm, and 656.27 nm using the following formula:
νd=(nd-1)/(nF-nC)
nd: refractive index at wavelength 587.56 nm,
nF: refractive index at a wavelength of 486.13 nm,
nC: means the refractive index at a wavelength of 656.27 nm.

<Raw materials for thermoplastic resin>
(Diol component of formula (1))
The diol component serving as a raw material of formula (1) is mainly a diol component represented by the following formula (a), and may be used alone or in combination of two or more types.

(In formula (a), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring.)
R ¹ , R ² , R ³ , and R ⁴ in formula (a) have the same meanings as R ¹ , R ² , R ³ , and R ⁴ in formula (1), and their preferred ranges are also the same.

The diol represented by the formula (a) can be obtained by subjecting a hydroxyketone represented by the following formula (5) and erythritol represented by the following formula (6) to a cyclodehydration reaction. Erythritol is known as a natural sweetener and can be produced by fermenting corn using enzymes. In the present invention, it is preferable to use raw materials that are not derived from petroleum.

(In formula (5), R ⁷ represents a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁸ represents a hydrogen atom having 1 to 10 carbon atoms. It represents 10 divalent acyclic hydrocarbon groups or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁷ and R ⁸ may be bonded to each other to form a ring. )

R ⁷ in formula (5) represents a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms; is preferably an acyclic hydrocarbon group, more preferably a hydrogen atom or a methyl group, and particularly preferably a methyl group.

R ⁸ in formula (5) each independently represents a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms; A divalent acyclic hydrocarbon group having 1 to 3 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 6 carbon atoms is preferred, and a methylene group is more preferred.

In the above formula (5), R ⁷ and R ⁸ may be bonded to each other to form a ring, and preferred examples of the structure include those represented by the following structural formula (a-1). Among these, it is particularly preferable that the ring structure is cyclohexane from the viewpoint of heat resistance.

(In formula (a-1), L and k are the same as in formula (1-a) above.)
In the formula (a-1), L represents a divalent linking group, preferably an alkylene group having 1 to 4 carbon atoms, more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

The purity of the diol compound represented by the formula (a) of the present invention is preferably 95% or more, more preferably 97% or more, and even more preferably 98% or more. Purity is determined by gas chromatography.

<Method for producing diol compound>
The diol compound represented by the above formula (a) of the present invention is obtained by dehydrating hydroxyketones represented by the above formula (5) and erythritol represented by the above formula (6) in the presence of an acid catalyst and a solvent. Obtained by cyclization reaction. In particular, it is preferably synthesized from raw materials that are not derived from petroleum.

In the production method of the present invention, the usage ratio of the hydroxyketones represented by the above formula (5) is preferably 1.8 to 2.4 mol per 1 mol of erythritol represented by the above formula (6), More preferably 1.9 to 2.1 mol.

Examples of acid catalysts include oxalic acid, acetic acid, hydrochloric acid, sulfuric acid, phosphoric acid, benzenesulfonic acid, p-toluenesulfonic acid, methanesulfonic acid, and heteropolyacid; Preferred is p-toluenesulfonic acid, more preferred.

The amount of the acid catalyst used in the present invention is preferably 0.001 to 1 mol, more preferably 0.005 to 0.1 mol, and still more preferably 0.01 to 0.05 mol, per 1 mol of erythritol. preferable.

Examples of the solvent include benzene, toluene, xylene, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, tetrahydrofuran, dioxane, and dimethylsulfoxide, with toluene and dimethylformamide being preferred. These solvents may be used alone or in combination of two or more.

The amount of the solvent is preferably 1 to 100 times the weight of erythritol, more preferably 3 to 50 times, and even more preferably 5 to 20 times the weight.

In the method for producing a diol compound, it is preferable to attach a Dean-Stark device on top of the reactor to remove by-product water from the system.

In the method for producing a diol compound, the reaction temperature for the dehydration condensation reaction is preferably 60 to 150°C, more preferably 80 to 130°C, and even more preferably 100 to 120°C.

Although the reaction can be carried out in the atmosphere, from the viewpoint of safety and hue, it is preferable to carry out the reaction in an atmosphere of an inert gas such as nitrogen or argon. The reaction can be followed by analytical means such as gas chromatography or liquid chromatography.

(Carbonate component of formula (1) above)
Examples of the carbonate component used in the unit represented by formula (1) of the thermoplastic resin of the present invention include phosgene and carbonate ester. Examples of the carbonate ester include esters of an optionally substituted aryl group having 6 to 10 carbon atoms, an aralkyl group, or an alkyl group having 1 to 4 carbon atoms. Specifically, diaryl carbonates such as diphenyl carbonate, ditolyl carbonate, bis(chlorophenyl) carbonate, bis(m-cresyl) carbonate, and dinaphthyl carbonate, dialkyl carbonates such as dimethyl carbonate, diethyl carbonate, dibutyl carbonate, and dicyclohexyl carbonate, and ethyl carbonates. Examples include alkylaryl carbonates such as phenyl carbonate and cyclohexylphenyl carbonate, and dialkenyl carbonates such as divinyl carbonate, diisopropenyl carbonate and dipropenyl carbonate, among which diaryl carbonates are preferred, and diphenyl carbonate is more preferred.

(Dicarboxylic acid component of formula (1) above)
The dicarboxylic acid component used in the unit represented by formula (1) of the thermoplastic resin of the present invention is preferably a dicarboxylic acid represented by formula (b) or an ester-forming derivative thereof.

In the formula (b), X represents a divalent linking group.
Typical specific examples of the dicarboxylic acid represented by the above formula (b) or its ester-forming derivative are shown below, but the raw materials used in the above formula (b) of the present invention are not limited thereto. do not have.

Dicarboxylic acid components used in the thermoplastic resin of the present invention include aliphatic dicarboxylic acid components such as malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, methylmalonic acid, and ethylmalonic acid. , monocyclic aromatic dicarboxylic acid components such as phthalic acid, isophthalic acid, and terephthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, 2,3-naphthalene dicarboxylic acid, 1,4-naphthalene dicarboxylic acid acid, 1,8-naphthalene dicarboxylic acid, anthracene dicarboxylic acid, phenanthrene dicarboxylic acid, 9,9-bis(carboxymethyl)fluorene, 9,9-bis(1-carboxyethyl)fluorene, 9,9-bis(1- carboxypropyl) fluorene, 9,9-bis(2-carboxypropyl)fluorene, 9,9-bis(2-carboxy-1-methylethyl)fluorene, 9,9-bis(2-carboxy-1-methylpropyl) Fluorene, 9,9-bis(2-carboxybutyl)fluorene, 9,9-bis(2-carboxy-1-methylbutyl)fluorene, 9,9-bis(5-carboxypentyl)fluorene, 9,9-bis( polycyclic aromatic dicarboxylic acid components such as carboxycyclohexyl) fluorene, 2,2'-bis(carboxymethoxy)-1,1'-binaphthyl, biphenyldicarboxylic acid components such as 2,2'-biphenyldicarboxylic acid, 1, Examples include alicyclic dicarboxylic acid components such as 4-cyclohexanedicarboxylic acid and 2,6-decalindicarboxylic acid. These may be used alone or in combination of two or more. Further, as the ester-forming derivative, acid chloride and esters such as methyl ester, ethyl ester, and phenyl ester may be used.

(Components of the above formula (4))
The thermoplastic resin of the present invention may further have a structural unit of the above formula (4), and the dihydroxy compound component serving as the raw material of the above formula (4) is shown below. These may be used alone or in combination of two or more.

The dihydroxy compound component serving as a raw material for the formula (4) of the present invention is 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)- 3-methylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-cyclohexylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)-3-phenylphenyl)fluorene , 9,9-bis(4-hydroxyphenyl)fluorene, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene, 9,9-bis(4-hydroxy-3-cyclohexylphenyl)fluorene, 9, Examples include 9-bis(4-hydroxy-3-phenylphenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-hydroxyethoxy) )-3-phenylphenyl)fluorene and 9,9-bis(4-hydroxy-3-methylphenyl)fluorene are particularly preferred. These may be used alone or in combination of two or more.

In addition, the thermoplastic resin of the present invention may optionally contain heat stabilizers, plasticizers, light stabilizers, polymerized metal deactivators, flame retardants, lubricants, antistatic agents, surfactants, antibacterial agents, oxidizing agents, etc. Additives such as inhibitors, ultraviolet absorbers, and mold release agents can be added.

The thermoplastic resin of the present invention is produced, for example, by a method in which a dihydroxy compound component is reacted with a carbonate precursor such as a diester carbonate, or a method in which a diol component is reacted with a dicarboxylic acid or its ester-forming derivative. A specific example is shown below.

<Manufacturing method>
(Production method of polycarbonate resin)
When the thermoplastic resin of the present invention is a polycarbonate resin, it can be obtained by a reaction method known per se, for example, by reacting a dihydroxy compound component with a carbonate precursor by a melt polymerization method. When producing a polycarbonate resin, a catalyst, a terminal stopper, an antioxidant, etc. may be used as necessary.

(Production method of polyester resin)
When the thermoplastic resin of the present invention is a polyester resin, a reaction product obtained by performing an esterification reaction or transesterification reaction between a dihydroxy compound component and a dicarboxylic acid or an ester-forming derivative thereof using a reaction method known per se, for example, a dihydroxy compound component and a dicarboxylic acid or an ester-forming derivative thereof. may be subjected to a polycondensation reaction to obtain a polymer having a desired molecular weight.

(Production method of polyester carbonate resin)
When the thermoplastic resin of the present invention is a polyester carbonate resin, it can be produced by reacting a dihydroxy compound component and a dicarboxylic acid or an ester-forming derivative thereof with a carbonate precursor such as a carbonate ester. As the polymerization method, the same method as for the polycarbonate resin or polyester resin can be used.

<Optical members>
The optical member of the present invention is formed from the above thermoplastic resin. Such optical members include, but are not limited to, optical lenses, optical discs, transparent conductive substrates, optical cards, sheets, films, optical fibers, lenses, and prisms as long as they are used for optical applications where the above-mentioned thermoplastic resins are useful. , optical films, substrates, optical filters, hard coat films, etc.

The optical member of the present invention can be molded and processed by any method such as injection molding, compression molding, injection compression molding, melt extrusion molding, and casting.

<Optical lens>
As the optical member of the present invention, an optical lens can be mentioned in particular. Examples of such optical lenses include optical lenses for mobile phones, smartphones, tablet terminals, personal computers, digital cameras, video cameras, in-vehicle cameras, surveillance cameras, and the like.

The optical lens of the present invention can be molded and processed by any method such as injection molding, compression molding, injection compression molding, melt extrusion molding, and casting, but injection molding is particularly suitable.

The molding conditions for injection molding are not particularly limited, but the cylinder temperature of the molding machine is preferably 180 to 320°C, more preferably 220 to 300°C, and particularly preferably 240 to 280°C. Further, the mold temperature is preferably 70 to 130°C, more preferably 80 to 125°C, and particularly preferably 90 to 120°C. The injection pressure is preferably 5 to 170 MPa, more preferably 50 to 160 MPa, particularly preferably 100 to 150 MPa.

The present invention will be explained in more detail with reference to the following examples, but the present invention is not limited thereto.
≪Evaluation method≫
<Compound having a tetraoxadecalin skeleton>
<NMR>
The structure of the obtained diol compound was identified by ¹ HNMR measurement using JNM-ECZ400S manufactured by JEOL Ltd. DMSO- _d6 was used as the solvent.
<Purity>
Measurement was performed using a single quadrupole GC/MS 5977B manufactured by Agilent Technologies under the following measurement conditions. In the examples, unless otherwise specified, purity (%) is an area percentage value corrected by excluding the solvent in GC/MS.
(GC)
Column: DB-1 (inner diameter 0.25 mm, length 30 m, film thickness 0.25 μm)
Injection volume: 1μl
Injection method: split ratio 40:1
Inlet temperature: 280℃
Oven: 60℃-10℃/min-280℃ (28 minutes)
Carrier gas: He, linear velocity 36.6 cm/s
(MS)
Ion source temperature: 230℃
Ionization mode: EI 70eV
Measurement range: m/z 33-700

<Thermoplastic resin>
<Copolymerization ratio>
The composition ratio of each thermoplastic resin was calculated by subjecting the obtained resin to ¹ HNMR measurement using JNM-ECZ400S manufactured by JEOL Ltd. DMSO- _d6 was used as the solvent.
<Molecular weight>
The molecular weight distribution was measured using gel permeation chromatography (GPC) under the following conditions, and the number average molecular weight (Mn) and weight average molecular weight (Mw) were determined.
10 mg of the obtained resin was dissolved in 5 mL of chloroform to prepare a solution.
(Measurement condition)
Equipment: HLC-8420 manufactured by Tosoh Corporation
Column: TSKgel SupermultiporeHZM-M×3+TSKgel guardcolumn manufactured by Tosoh Corporation
Flow rate: 0.350mL/min
Detection conditions: UV254nm
Column temperature: 40.0℃
Eluent: Chloroform <water absorption>
A 3 mm thick molded plate of each resin was produced by compression molding, dried at 80°C for 12 hours, immersed in 23°C water, taken out periodically, measured its weight, and calculated the water absorption rate. It was calculated using the following formula. The measurements were performed on three molded plate samples for each thermoplastic resin, and the average value was taken as the water absorption rate.
Water absorption rate (%) = (mass of formed plate after water absorption - mass of formed plate before water absorption) / mass of formed plate before water absorption x 100
<5% weight loss temperature>
The obtained resin was measured in a nitrogen atmosphere at a heating rate of 20° C./min using a differential thermal/thermogravimetric simultaneous measuring device Discovery SDT650 manufactured by TA Instruments, and the 5% weight loss temperature was measured. The sample was measured at approximately 5 mg.

<Optical properties>
(Refractive index)
A 3 mm thick test piece of each resin was produced by compression molding, and after polishing, the refractive index nd (587.56 nm) at 20° C. was measured using a Karnew precision refractometer KPR-2000 manufactured by Shimadzu Corporation.
(Abbe number)
The measurement wavelength of Abbe's number was calculated from the refractive index of 486.13 nm, 587.56 nm, and 656.27 nm using the following formula.
νd=(nd-1)/(nF-nC)
nd: refractive index at wavelength 587.56 nm,
nF: refractive index at wavelength 486.13 nm,
nC: means the refractive index at a wavelength of 656.27 nm.
<Biomass degree>
The weight ratio of structural units synthesized from plant-derived resources among all the structural units constituting the thermoplastic resin was calculated.

[Example 1] Synthesis of 2,6-bis(hydroxymethyl)-2,6-dimethyl-1,3,5,7-tetraoxadecalin (hereinafter sometimes abbreviated as MMTOD) Stirring under nitrogen atmosphere 10.00 g of meso-erythritol (raw material not derived from petroleum), 12.13 g of hydroxyacetone, 0.31 g of p-toluenesulfonic acid monohydrate, and toluene in a flask equipped with a vacuum cleaner, condenser, Dean-Stark tube, and thermometer. 75 ml of dimethylformamide and 7 ml of dimethylformamide were added, and the mixture was reacted at 110° C. for 5 hours. After the reaction was completed, the reaction solution was concentrated using an evaporator, and the crude product after concentration was purified by a column (developing solvent was ethyl acetate:hexane=2:1). The eluate from which only the main component was separated was concentrated using an evaporator and then dried to obtain 13.15 g of MMTOD (yield: 69%, purity: 98.39). Note that MMTOD has the following chemical structure.

[Example 2] Production of polycarbonate resin 2.3 parts by mass (20 mol%) of MMTOD, 9,9-bis[4-(2-hydroxyethoxy)phenyl]fluorene (hereinafter sometimes abbreviated as BPEF) 17 .54 parts by mass (80 mol%), 10.82 parts by mass (101 mol%) of diphenyl carbonate (hereinafter sometimes abbreviated as DPC), and 2.10× sodium hydrogen carbonate at a concentration of 60 mmol/L as a catalyst. 10 ⁻⁴ parts by mass (5.00×10 ⁻³ mol %) was added and heated to 180° C. in a nitrogen atmosphere to melt. Thereafter, the degree of pressure reduction was adjusted to 20 kPa over a period of 5 minutes. The temperature was raised to 250 °C at a temperature increase rate of 40 °C/hr, and after the outflow of phenol reached 70%, the pressure was reduced at 40 kPa/hr, and the polymerization reaction was carried out until the predetermined power was reached, and the reaction was completed. The resin was then removed from the flask. The obtained polycarbonate resin was analyzed by ¹ HNMR, and it was confirmed that the MMTOD component was introduced in an amount of 20 mol% based on the total monomer components, and the BPEF component was introduced in an amount of 80 mol% based on the total monomer components. Using the polycarbonate resin, the copolymerization ratio, molecular weight, refractive index, Abbe number, water absorption, and 5% weight loss temperature were evaluated, and the results are shown in Table 1 and the biomass degree is shown in Table 2. Note that BPEF has the following chemical structure.

[Example 3] Production of polycarbonate resin A polycarbonate resin was produced in the same manner as in Example 1, except that the ratio of MMTOD and BPEF was changed to 36:64 (mol%). Using the polycarbonate resin, the copolymerization ratio, molecular weight, refractive index, Abbe number, water absorption, and 5% weight loss temperature were evaluated, and the results are shown in Table 1 and the biomass degree is shown in Table 2.

[Example 4] Production of polycarbonate resin A polycarbonate resin was produced in the same manner as in Example 1, except that the ratio of MMTOD and BPEF was changed to 49:51 (mol%). Using the polycarbonate resin, the copolymerization ratio, molecular weight, refractive index, Abbe number, water absorption, and 5% weight loss temperature were evaluated, and the results are shown in Table 1 and the biomass degree is shown in Table 2.

[Comparative Example 1] Manufacture of polycarbonate resin Implemented except that isosorbide (hereinafter sometimes abbreviated as "ISS") was used instead of MMTOD and the ratio of ISS and BPEF was changed to 20:80 (mol%) A polycarbonate resin was produced in the same manner as in Example 1. Using the polycarbonate resin, the copolymerization ratio, molecular weight, refractive index, Abbe number, water absorption, and 5% weight loss temperature were evaluated, and the results are shown in Table 1 and the biomass degree is shown in Table 2. Note that ISS has the following chemical structure.

[Comparative Example 2] Production of polycarbonate resin A polycarbonate resin was produced in the same manner as in Example 1, except that ISS was used instead of MMTOD and the ratio of ISS and BPEF was changed to 40:60 (mol%). Using the polycarbonate resin, the copolymerization ratio, molecular weight, refractive index, Abbe number, water absorption, and 5% weight loss temperature were evaluated, and the results are shown in Table 1 and the biomass degree is shown in Table 2.

The thermoplastic resins obtained in Examples 2 to 4 maintain excellent optical properties equivalent to ISS without increasing water absorption even when the ratio of MMTOD is increased, and the degree of biomass can be increased. I can do it. On the other hand, although the thermoplastic resin of the comparative example has excellent optical properties, when the copolymerization ratio is increased, the water absorption rate increases and the degree of biomass cannot be increased.

A structure like MMTOD has a low water absorption rate while maintaining excellent optical properties, so it is effective in lowering the refractive index, increasing the Abbe number, and increasing the degree of biomass.

The thermoplastic resin of the present invention has excellent optical properties and low water absorption, and is therefore suitable for use as an optical material, specifically for optical lenses, prisms, optical discs, transparent conductive substrates, optical cards, sheets, films, etc. It can be used as optical members such as optical fibers, optical films, optical filters, and hard coat films, and is particularly useful as an optical lens material.

Claims (17)

A thermoplastic resin containing a structural unit represented by the following formula (1).
(In formula (1), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring. W is at least one selected from the group consisting of the following formula (2) and the following formula (3). .)
(In the formula, X represents a divalent linking group.) The thermoplastic resin according to claim 1, wherein the structural unit represented by the formula (1) accounts for 5 mol% to 100 mol% of all structural units constituting the thermoplastic resin. The thermoplastic resin according to claim 1 or 2, wherein R ¹ and R ² in the formula (1) are methyl groups. The thermoplastic resin according to any one of claims 1 to 3, wherein R ³ and R ⁴ in the formula (1) are methylene groups. The thermoplastic resin according to any one of claims 1 to 4, further comprising a structural unit represented by the following formula (4).
(In formula (4), R ⁵ and R ⁶ are the same or different and represent a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and L ¹ and L ² each independently represent a divalent linking group. (m and n each independently represent 0 or 1.) The thermoplastic resin according to any one of claims 1 to 5, wherein in the formula (1), W is the formula (2). The thermoplastic resin according to any one of claims 1 to 6, which has a water absorption rate of 0.25% or less after immersion at 23°C for 24 hours. The thermoplastic resin according to any one of claims 1 to 7, which has a biomass degree of 5% or more. The thermoplastic resin according to any one of claims 1 to 8, which has a 5% weight loss temperature of 350°C or higher. The thermoplastic resin according to any one of claims 1 to 9, having a refractive index of 1.450 to 1.650. The thermoplastic resin according to any one of claims 1 to 10, which has an Abbe number of 20 to 65. An optical member formed from the thermoplastic resin according to any one of claims 1 to 11. The optical member according to claim 12, which is an optical lens. A diol compound represented by the following formula (a).
(In formula (a), R ¹ and R ² each independently represent a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, R ³ and R ⁴ each independently represent a divalent acyclic hydrocarbon group having 1 to 10 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. ¹ and R ³ or R ² and R ⁴ may be bonded to each other to form a ring.) The diol compound according to claim 14, wherein R ¹ and R ² in the formula (a) are methyl groups. The diol compound according to claim 14 or 15, wherein R ³ and R ⁴ in the formula (a) are methylene groups. 15. The method for producing a diol compound according to claim 14, wherein hydroxyketones represented by the following formula (5) and erythritol represented by the following formula (6) are subjected to a cyclodehydration reaction in the presence of an acid catalyst and a solvent.
(In formula (5), R ⁷ represents a hydrogen atom, an acyclic hydrocarbon group having 1 to 10 carbon atoms, or an alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁸ represents a hydrogen atom having 1 to 10 carbon atoms. It represents 10 divalent acyclic hydrocarbon groups or a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms, and R ⁷ and R ⁸ may be bonded to each other to form a ring. )