JP6358062B2 - Polyester resin - Google Patents

Description

  The present invention relates to a polyester resin having a furan structure. More specifically, the present invention relates to a polyester resin having a flange carboxylic acid structure in the main chain, capable of being produced from a raw material derived from biomass, and excellent in polymerizability, breaking strength and transparency.

  The polyester resin is a resin having excellent versatility and is used in a wide range of applications as a resin having excellent heat resistance and mechanical properties. For example, aromatic polyester resins such as poly (cyclohexanedimethylene) terephthalate (hereinafter abbreviated as “PCT”), polyethylene terephthalate (hereinafter abbreviated as “PET”), polybutylene terephthalate (hereinafter abbreviated as “PBT”) Films, food containers, electric / electronic parts, home appliance housings, automobile materials, etc. are widely used as general-purpose engineering parts-related materials (Patent Documents 1 and 2).

  On the other hand, in recent years, polyester resins using biodegradable resins and biomass-derived raw materials have been developed as environmentally friendly or environmentally sustainable materials. Among these, a polyester resin using a furan carboxylic acid that can be produced from biomass as a raw material has been developed. In Non-Patent Document 1, it can be used as a thermoplastic resin having excellent heat resistance. Is disclosed. In addition, a polyester resin using, as a raw material, a flanged carboxylic acid synthesized with a specified degree of polymerization and increased mechanical strength is disclosed (Patent Document 3). Furthermore, a polyester resin having a high molecular weight and good mechanical properties and hydrolysis resistance is disclosed (Patent Document 4).

International Publication 90/07534 JP2013-221098 JP2007-146153 JP2008-291243

Y. Hachihama et al, Osaka Daigaku Kogaku Hokoku, 8, 475-480 (1958) “Synthesis of Polyesters containing Fran Ring”

Polyester resins such as PCT, PET, and PBT are made from petroleum and are difficult to produce from biomass, or production from biomass is very expensive and has no prospect of practical use. .
On the other hand, the polyester resin disclosed in Non-Patent Document 1 for the polyester resin using furan carboxylic acid that can be produced from biomass as a raw material has insufficient mechanical properties because its molecular weight is low, It could not withstand practical use. Moreover, the polyester resin using the flange carboxylic acid of patent documents 3 and 4 as a raw material has not yet been enough as mechanical properties. In order to further increase the molecular weight in order to further improve the mechanical properties of the polyester resins of Patent Documents 3 and 4, there is a problem that it takes time for the polymerization reaction. Moreover, in order to raise breaking strength, it is necessary to improve crystallinity, and the polyester resin of patent document 3 and 4 also had the problem of impairing transparency.

  The object of the present invention is a polyester resin having a flange carboxylic acid structure that solves the above-mentioned problems and can be produced from a biomass-derived raw material, and has excellent balance of polymerizability, breaking strength and transparency. It is to provide a resin.

  As a result of intensive studies to solve the above problems, the present inventor includes a repeating unit represented by the formula (1) and the formula (2), and the repeating represented by the formula (2) in the polyester resin. It has been found that the unit is a specific ratio, and the polymerizability, breaking strength and transparency are excellent in balance, and the present invention has been completed.

  That is, the gist of the present invention is as follows.

[式（１）において、Ａは脂肪族炭化水素基を表す。]

[式（２）において、Ｂは数平均分子量が２００以上、６０００以下のポリオキシアルキ
レン基を表す。]
［２］前記式（１）のＡが環状の脂肪族炭化水素基を含むものである、［１］に記載のポリエステル樹脂。
［３］前記ポリエステル樹脂の還元粘度が０．５ｄｌ/ｇ以上である、［１］又は［２］
に記載のポリエステル樹脂。
［４］前記ポリエステル樹脂の引張破断強度が１２ＭＰａ以上である、［１］〜［３］の何れか１に記載のポリエステル樹脂。
［５］厚み２００μｍにおける光線透過率が７５％以上である、［１］〜［４］の何れか１に記載のポリエステル樹脂。 [1] The ratio of the repeating unit represented by the formula (2) in the polyester resin is 0.5 mol% or more and 50 mol% or less, including the repeating unit represented by the formula (1) and the formula (2). Polyester resin characterized by being.

[In Formula (1), A represents an aliphatic hydrocarbon group. ]

[In the formula (2), B represents a polyoxyalkylene group having a number average molecular weight of 200 or more and 6000 or less. ]
[2] The polyester resin according to [1], wherein A in the formula (1) includes a cyclic aliphatic hydrocarbon group.
[3] The reduced viscosity of the polyester resin is 0.5 dl / g or more, [1] or [2]
The polyester resin as described in.
[4] The polyester resin according to any one of [1] to [3], wherein the polyester resin has a tensile strength at break of 12 MPa or more.
[5] The polyester resin according to any one of [1] to [4], wherein the light transmittance at a thickness of 200 μm is 75% or more.

  According to the present invention, the polyester resin containing a repeating unit represented by the formula (1) and the formula (2) having a furandicarboxylic acid structure, which can be produced from a biomass-derived raw material, has a polymerizability, a breaking strength, And a polyester resin excellent in balance in transparency.

Below, the typical aspect for implementing this invention is demonstrated concretely, However, This invention is not limited to the following aspects, unless the summary is exceeded.

[Polyester resin]
The polyester resin of the present invention contains repeating units represented by the formulas (1) and (2), and the ratio of the repeating units represented by the formula (2) in the polyester resin is 0.5 mol% or more, 50 It is characterized by being not more than mol%.

[式（１）において、Ａは脂肪族炭化水素基を表す。]

[式（２）において、Ｂは数平均分子量が２００以上、６０００以下のポリオキシアルキ
レン基を表す。]

[In Formula (1), A represents an aliphatic hydrocarbon group. ]

[In the formula (2), B represents a polyoxyalkylene group having a number average molecular weight of 200 or more and 6000 or less. ]

The reason why the polyester resin of the present invention is excellent in the polymerizability, breaking strength and transparency is estimated as follows.
In the polyester resin of the present invention, when the furandicarboxylic acid is used in combination with the A component and the B component, the compatibility of each component is improved, and as a result, high polymerizability tends to be obtained. The polyester resin of the present invention is a repeating unit represented by the formula (1) and the formula (2), although the crystalline portion of the polyester resin having furan carboxylic acid as a monomer is a hard segment and the amorphous portion is a soft segment. In a specific range, it is considered that the balance between the hard segment and the soft segment is maintained, and the breaking strength and elongation at break are excellent. Furthermore, the crystallinity of the polyester resin is too strong with only the repeating unit represented by the formula (1), whereas the repeating unit represented by the formula (1) and the formula (2) is included in a specific range. It is estimated that the balance between the high crystallinity component and the low crystallinity component is improved, and the transparency of the polyester resin is improved.

In the polyester resin of the present invention, the proportion of the repeating unit represented by the formula (2) is 0.5 mol% or more, preferably 1.0 mol% or more, more preferably 1.5 mol% or more. is there. Moreover, it is 50 mol% or less, Preferably it is 45 mol% or less, More preferably, it is 40 mol% or less. By being in these ranges, the balance between the crystal part and the amorphous part in the polyester resin becomes good, and the breaking strength and transparency tend to be improved.
The method for setting the ratio of the repeating unit represented by the formula (2) to the above range is not particularly limited. For example, in the production of the polyester resin of the present invention, from the number average molecular weight of the diol unit containing B, the formula (1) And the number of moles of the repeating unit represented by formula (2) and the amount of the diol unit containing B are adjusted.

  The polyester resin of the present invention may have a plurality of repeating units represented by the formulas (1) and (2) as long as the effects of the present invention are not impaired. Moreover, units other than the repeating units represented by formula (1) and formula (2) may be included.

<Repeating unit represented by formula (1)>
The repeating unit represented by the formula (1) includes a diol unit containing A and a 2,5-furandicarboxylic acid unit.

(A)
A in Formula (1) is an aliphatic hydrocarbon group.
(Aliphatic hydrocarbon group)
Examples of the aliphatic hydrocarbon group include linear, cyclic, and combinations thereof, and these may have a branch. Moreover, you may have an unsaturated bond. Specific examples include an alkylene group, an alkenylene group, an alkynylene group, a cycloalkylene group, a cycloalkenylene group, a cycloalkynylene group, and a group obtained by combining these.
The number of carbon atoms of the aliphatic hydrocarbon group is preferably 2 or more, preferably 20 or less, more preferably 18 or less, and particularly preferably 16 or less. By being in these ranges, the polymerizability of the polyester resin tends to be improved.
The aliphatic hydrocarbon group may have a substituent, and examples thereof include an alkyl group having 1 to 4 carbon atoms and a halogen atom. Among these, from the viewpoint of improving the polymerizability, it preferably has no substituent or an alkyl group having 1 to 4 carbon atoms as a substituent, and more preferably has no substituent.
Among these, those containing a cyclic aliphatic hydrocarbon group are preferable because the mechanical properties of the polyester resin are improved.

Examples of the linear aliphatic hydrocarbon group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, a dodecylene group, and —C ₂ H _{4. OC 2 H 4 -, - CH} (C 2 H 5) CH 2 -, - CH (CH 3) C 2 H 5 -, - CH 2 CH (C 2 H 5) CH (C 3 H 7) - and the like Can be mentioned. Among these, a linear alkylene group is preferable, and a butylene group is particularly preferable because a hard segment having high crystallinity tends to be obtained in the polyester resin.
Examples of the cyclic aliphatic hydrocarbon group include a cyclobutylene group, a cyclohexylene group, a cyclooctylene group, a cyclodecylene group, a cyclododecylene group, a furan-derived group, and an isosorbite-derived group. Among these, a cycloalkylene group is preferable, and a cyclohexylene group is particularly preferable from the viewpoint of improvement in heat resistance of the polyester resin and ease of production of the polyester resin.
Examples of the group obtained by combining the linear and cyclic aliphatic hydrocarbon groups include those obtained by combining the groups listed as examples of the above linear and cyclic aliphatic hydrocarbon groups. Examples thereof include a cyclobutane dimethylene group, a cyclohexane dimethylene group, a cyclooctane dimethylene group, a cyclodecane dimethylene group, a cyclododecane dimethylene group, and a 2,5-furandylene methylene group. Among these, a group in which the linear aliphatic hydrocarbon group has 1 to 4 carbon atoms and the cyclic aliphatic hydrocarbon group has 5 to 10 carbon atoms in combination is preferable, Furthermore, a cyclohexane dimethylene group is preferable. By being these groups, it exists in the tendency which is excellent in synthetic | combination ease, breaking strength, and elongation at break.

<Repeating unit represented by formula (2)>
The repeating unit represented by the formula (2) includes a diol unit containing B and a 2,5-furandicarboxylic acid unit.

(B)
B in Formula (2) is a polyoxyalkylene group having a number average molecular weight of 200 or more and 6000 or less. The average molecular weight of the polyoxyalkylene group is 200 or more, preferably 300 or more, more preferably 400 or more. Moreover, it is 6000 or less, Preferably it is 5500 or less, More preferably, it is 5000 or less. When the number average molecular weight is equal to or higher than the lower limit value, the mechanical performance of the polyester resin tends to be obtained, and when the number average molecular weight is equal to or lower than the upper limit value, the polyester resin is not phase-separated and mechanical performance is also obtained. Tend to be.
Number average molecular weight can be measured by raising boiling point, lowering freezing point, terminal group determination, vapor pressure penetration, gel permeation chromatography, etc.

The number of carbon atoms of the oxyalkylene group, which is a repeating unit in the polyoxyalkylene group, is not particularly limited, but it is 1 or more, preferably 2 or more, preferably 10 or less, and 8 or less. Is more preferable. The oxyalkylene group may be linear or branched.
Examples of the polyoxyalkylene group include a group represented by the following structure, or a derivative thereof. N in the following structure is not particularly limited, and can be appropriately adjusted so as to have the above-mentioned B number average molecular weight.

Among these, B is preferably the following structure because the mechanical performance of the polyester resin tends to be high.

<Other structural units>
The polyester resin of the present invention has other dicarboxylic acid units and / or diol units in addition to the 2,5-furandicarboxylic acid units and diol units contained in the above formulas (1) and (2), respectively. It may have a structural unit derived from a copolymer component other than a dicarboxylic acid unit and a diol unit. In obtaining the effect of the polyester resin of the present invention with certainty, the content of structural units derived from other components other than the formula (1) and the formula (2) contained in the polyester resin of the present invention constitutes the polyester resin. It is preferable that it is 10 mol% or less with respect to all the structural units derived from the raw material monomer (monomer) to perform, especially 5 mol% or less.

  The structural unit of other components other than Formula (1) and Formula (2) is, for example, as a raw material when the polyester resin of the present invention is produced according to the method for producing a polyester resin of the present invention, which will be described later. And a component monomer of the formula (2) that can be copolymerized is introduced.

The copolymerizable raw material monomers include aromatic dihydroxy compounds, bisphenols, aliphatic (including alicyclic) dicarboxylic acids, hydroxycarboxylic acids, diamines, and derivatives thereof, as well as trifunctional or more functional groups. And the like.

Specific examples of copolymerizable aliphatic (including alicyclic) dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, dimer acid, dodecanedioic acid, and 1,6-cyclohexanedicarboxylic acid. Etc. These may be acid anhydrides. Examples of the derivatives of aliphatic (including alicyclic) dicarboxylic acids include lower alkyl esters of these aliphatic (including alicyclic) dicarboxylic acids. Among these, succinic acid, glutaric acid, sebacic acid, dimer acid and dodecanedioic acid, and their lower alkyl (for example, alkyl having 1 to 4 carbon atoms) ester derivatives are preferable, and in particular, lower succinic acid and succinic acid. Alkyl ester derivatives or mixtures thereof are preferred.
These may be used individually by 1 type, and may mix and use 2 or more types.

The copolymerizable hydroxycarboxylic acid and hydroxycarboxylic acid derivative are not particularly limited as long as they are compounds having one hydroxyl group and carboxyl group in the molecule or derivatives thereof. Specific examples of hydroxycarboxylic acid and derivatives thereof include lactic acid, glycolic acid, 2-hydroxy-n-butyric acid, 2-hydroxycaproic acid, 6-hydroxycaproic acid, 2-hydroxy-3,3-dimethylbutyric acid, 2- Examples thereof include hydroxy-3-methylbutyric acid, 2-hydroxyisocaproic acid, mandelic acid, salicylic acid, and esters, acid chlorides, acid anhydrides and the like thereof.
These may be used individually by 1 type, and may mix and use 2 or more types.

  Further, when optical isomers are present in these, any of D-form, L-form, and racemate may be used, and the form may be any of solid, liquid, or aqueous solution.

  The compound having a trifunctional or higher functional group includes a trifunctional or higher polyhydric alcohol; a trifunctional or higher polyvalent carboxylic acid or anhydride, acid chloride, or ester thereof; and a trifunctional or higher functional hydroxycarboxylic acid or its Examples thereof include at least one selected from the group consisting of anhydrides, acid chlorides, or esters; trifunctional or higher functional amines.

  Specific examples of the trifunctional or higher polyhydric alcohol include glycerin, trimethylolpropane, pentaerythritol and the like. These may be used individually by 1 type, and may mix and use 2 or more types.

  Specific examples of the trifunctional or higher polyvalent carboxylic acid or anhydride thereof include trimesic acid, propanetricarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, cyclopentatetracarboxylic anhydride Thing etc. are mentioned. These may be used individually by 1 type, and may mix and use 2 or more types.

  Specific examples of the tri- or higher functional hydroxycarboxylic acid include malic acid, hydroxyglutaric acid, hydroxymethylglutaric acid, tartaric acid, citric acid, hydroxyisophthalic acid, hydroxyterephthalic acid bishydroxymethylpropionic acid, bishydroxymethylbutyric acid, etc. Is mentioned. These may be used individually by 1 type, and may mix and use 2 or more types.

When the polyester resin of the present invention includes a structural unit derived from a compound having a functional group having three or more functional groups, the content ratio is 5 mol% with respect to the total of all the structural units constituting the polyester resin of the present invention. Or less, preferably 4 mol% or less, and most preferably 3 mol% or less.
When the content ratio of the structural unit derived from the compound having a trifunctional or higher functional group in the polyester resin of the present invention is in the above range, the crosslinking of the polymer proceeds appropriately, and the strand can be stably extracted. become. In addition, formability is easily obtained, and mechanical properties and the like tend to be maintained.

<Chain extender, end-capping agent>
In the production of the polyester resin of the present invention, chain extenders such as diisocyanate, diphenyl carbonate, dioxazoline, and silicate ester may be used. Particularly, when carbonate compounds such as diphenyl carbonate are used, these carbonate compounds are used. Polyester carbonate can also be obtained by adding 20 mol% or less, preferably 10 mol% or less with respect to all structural units of the polyester resin.

  In this case, as the carbonate compound, specifically, diphenyl carbonate, ditolyl carbonate, bis (chlorophenyl) carbonate, m-cresyl carbonate, dinaphthyl carbonate, dimethyl carbonate, diethyl carbonate, dibutyl carbonate, ethylene carbonate, diamyl Examples include carbonate and dicyclohexyl carbonate. In addition, carbonate compounds composed of the same or different hydroxy compounds derived from hydroxy compounds such as phenols and alcohols can also be used.

  Specific examples of the diisocyanate compound include 2,4-tolylene diisocyanate, a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, and 1,5-naphthylene diisocyanate. And known diisocyanates such as xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

Specific examples of the silicate ester include tetramethoxysilane, dimethoxydiphenylsilane, dimethoxydimethylsilane, and diphenyldihydroxylane.
In order to increase the melt tension, a small amount of peroxide may be added.
Any of these may be used alone or in combination of two or more.

  In the present invention, the polyester terminal group of the polyester resin may be sealed with carbodiimide, an epoxy compound, a monofunctional alcohol, or carboxylic acid.

In this case, examples of the carbodiimide compound of the end-capping agent include compounds having one or more carbodiimide groups in the molecule (including polycarbodiimide compounds). Specifically, the monocarbodiimide compound includes dicyclohexylcarbodiimide, diisopropyl. Carbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, t-butylisopropylcarbodiimide, diphenylcarbodiimide, di-t-butylcarbodiimide, di-β-naphthylcarbodiimide, N, N′-di-2,6-diisopropylphenylcarbodiimide, etc. Illustrated.
These may be used individually by 1 type, and may mix and use 2 or more types.

[Production method of polyester resin]
As a method for producing the polyester resin of the present invention, known methods relating to the production of polyester resins can be employed.
Moreover, the reaction conditions in this case can set the appropriate conditions employ | adopted conventionally, and are not restrict | limited in particular.

Specifically, the polyester resin of the present invention is used as necessary with a 2,5-furandicarboxylic acid component and a diol component, which are raw materials for the repeating units represented by the formulas (1) and (2). It can manufacture by performing esterification reaction or transesterification reaction using the other copolymerization component etc. which are followed, and performing polycondensation reaction subsequently. In the reaction, the above-mentioned chain extender or terminal blocking agent may be used as necessary.

  In the esterification or transesterification reaction, a 2,5-furandicarboxylic acid component and a diol component, and other copolymerization components used as necessary are charged into a reaction vessel equipped with a stirrer and a distillation pipe, preferably In the presence of a catalyst, the reaction is allowed to proceed while distilling out by-products such as moisture generated by the reaction while stirring under reduced pressure in an inert gas atmosphere. The use ratio of the raw materials, that is, the molar ratio of the total diol component to the total dicarboxylic acid component is usually 1.0 to 2.0 mol times.

<Raw Material of Repeating Unit Represented by Formula (1) and Formula (2)>
(Diol unit in the repeating unit represented by the formula (1))
The diol unit contained in the repeating unit represented by the formula (1) is, for example, a hydroxyl group in the aliphatic hydrocarbon group of A described above when a polyester resin is produced according to the method for producing a polyester resin of the present invention described later. Can be introduced by using one kind or two or more kinds of diols in which two are bonded. Specifically, ethylene glycol, diethylene glycol,
Propylene glycol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexaneanediol, 1,8- Octanediol, 2-ethyl-1,3-hexanediol, 1,9-nonanediol, 1,10-decanediol, cyclobutanedimethanol, cyclohexanedimethanol, cyclooctanedimethanol, cyclodecanedimethanol, cyclododecanedimethanol, Examples include diols including 2,5-furan, dimethanol, isosorbide and the like.

(Diol unit in the repeating unit represented by the formula (2))
Examples of the raw material of the diol unit contained in the repeating unit represented by the formula (B) include polyalkylene glycol in which a hydroxyl group and a hydrogen atom are bonded to the polyoxyalkylene group of B described above. Specific examples thereof include both-end ethylene oxide adducts that are polyoxyethylene glycol, polypropylene glycol, polytrimethylene glycol, polytetramethylene glycol, or derivatives thereof.

(2,5-furandicarboxylic acid unit in the repeating unit represented by formula (1) and formula (2)) 2,5-furandicarboxylic acid in the repeating unit represented by formula (1) and formula (2) For example, when the polyester unit of the present invention is produced according to the method for producing a polyester resin of the present invention described later, the acid unit is 2,5-furandicarboxylic acid and / or a derivative thereof (hereinafter referred to as “ It may be referred to as "2,5-furandicarboxylic acid component"). Here, examples of 2,5-furandicarboxylic acid derivatives include alkyl esters having 1 to 4 carbon atoms. Among them, methyl esters, ethyl esters, n-propyl esters, isopropyl esters and the like are preferable, and methyl esters are more preferable. is there. These may be used alone or in combination of two or more.

<Catalyst>
As the catalyst, any catalyst that can be used for the production of a polyester resin can be selected, but germanium, titanium, zirconium, hafnium, antimony, tin, magnesium, calcium, zinc, aluminum, cobalt, lead, cesium, Metal compounds such as manganese, lithium, potassium, sodium, copper, barium and cadmium are suitable. Among these, germanium compounds, titanium compounds, magnesium compounds, tin compounds, zinc compounds, and lead compounds are preferable from the viewpoint of high activity, and titanium compounds are particularly preferable.

  The titanium compound used as the catalyst is not particularly limited, and preferred examples include organic titanium compounds such as tetraalkoxytitanium such as tetrapropyl titanate, tetrabutyl titanate, tetraethyl titanate, tetrahydroxyethyl titanate, and tetraphenyl titanate. Is mentioned. Among these, tetrapropyl titanate, tetrabutyl titanate and the like are preferable from the viewpoint of price and availability, and the most preferable catalyst is tetrabutyl titanate from the viewpoint of high activity.

  These catalysts may be used individually by 1 type, and may mix and use 2 or more types. Moreover, unless the objective of this invention is impaired, combined use of another catalyst is not prevented.

  The amount of the catalyst used is a metal equivalent amount in the catalyst with respect to the produced polyester resin, and the lower limit is preferably 0.0001% by weight, more preferably 0.0005% by weight, and still more preferably 0.001% by weight. The upper limit is preferably 1% by weight, more preferably 0.5% by weight, and still more preferably 0.1% by weight. When the amount of the catalyst used is not less than the above lower limit, the reaction rate of the polymerization reaction can be increased, and by being not more than the above upper limit, the production cost relating to the catalyst can be suppressed, and the catalyst residue can be reduced. The stability of the resulting polyester resin tends to be obtained.

  The catalyst addition time is not particularly limited as long as it is before the start of the pressure reduction reaction, and may be added at the time of charging the raw materials, or may be added at the time of the start of pressure reduction. You may add separately at the time of raw material preparation and the time of pressure reduction start.

<Reaction conditions>
The production of the polyester resin of the present invention is carried out by increasing the degree of polymerization while distilling the distillate produced by the esterification or transesterification reaction out of the reaction system. The reaction is allowed to proceed by applying heat and reduced pressure. The temperature condition in this case is usually selected within the range of 150 to 300 ° C, preferably 160 to 290 ° C, more preferably 160 to 280 ° C. The pressure reduction is started when the temperature reaches an arbitrary temperature, and the final degree of pressure reduction is preferably 1.33 × 10 ³ Pa or less, more preferably 0.40 × 10 ³ Pa or less. The decompression time is selected in the range of 1 hour or more, preferably 2 to 15 hours.

  Among these reaction conditions, particularly when the polymerization temperature is in the upper range, thermal decomposition, coloring and side reactions are suppressed, the terminal acid value does not become too large, and a polyester resin having a sufficient degree of polymerization tends to be obtained. It is in.

  The polyester resin obtained by the melt polymerization may be subjected to solid phase polymerization at a temperature below the melting point. Since the polyester resin of the present invention has high crystallinity, the molecular weight can be easily increased by solid phase polymerization. In this case, the pellet or powder polyester resin is heated in a nitrogen gas atmosphere or under reduced pressure. In this case, the temperature condition is 80 to 260 ° C, preferably 100 to 250 ° C. When solid-phase polymerization is performed, the polymerization reaction is performed at a temperature lower than that of melt polymerization, so that thermal decomposition and side reactions are suppressed, a terminal acid value is low, coloring is good, and a resin having a large molecular weight is obtained. It tends to be easy.

[Physical properties of polyester resin]

<Reduced viscosity>
The reduced viscosity (ηsp / c) of the polyester resin of the present invention is preferably 0.5 dL / g or more, more preferably 0.6 dL / g or more, and further preferably 0.7 dL / g or more. Moreover, it is preferable that it is 4.0 dL / g or less, More preferably, it is 3.8 dL.
/ G or less, more preferably 3.5 dL / g or less. When the reduced viscosity is in the above range, a film or an injection-molded product can be molded, and the strength of the molded product tends to increase. The reduced viscosity (ηsp / c) of the polyester resin is measured by the method described in the Examples section below.

<Light transmittance>
The light transmittance of the polyester resin of the present invention is preferably 75% or more, more preferably 78% or more, and further preferably 80% or more. Moreover, there is no upper limit and the higher one is preferable. For the light transmittance of the polyester resin of the present invention, the polyester resin is a film having a thickness of 200 μm, the light transmittance between wavelengths of 400 nm to 800 nm is measured with an ultraviolet-visible spectrophotometer, and the value every 50 nm is averaged. It is calculated by requesting.

<Tensile breaking strength and tensile breaking elongation>
The tensile strength at break of the polyester resin of the present invention is preferably 12 MPa or more, more preferably 15 MPa or more, and still more preferably 20 MPa or more. There is no particular upper limit, and a larger value is preferable. When the tensile strength is 12 MPa or more, there is a tendency that sufficient strength as a practical material can be obtained.
The elongation at break of the polyester resin of the present invention is preferably 200% or more, more preferably 250% or more, and still more preferably 300% or more. There is no particular upper limit, and a larger value is preferable. It exists in the tendency which can obtain sufficient softness | flexibility as a practical material because breaking elongation is 200% or more.
The tensile breaking strength and tensile breaking elongation of the polyester resin are stress or elongation at break in a tensile test of a sample film obtained by molding the polyester resin, and are measured, for example, by the following tensile test.

<Tensile test>
The polyester resin is hot-pressed to produce a press film having a predetermined thickness (200 μm). A sample is punched into a dumbbell shape from the obtained press film, a tensile test is performed according to JIS K7127, and a tensile breaking strength and a tensile breaking elongation are measured.

[Polyester resin]
The polyester resin of the present invention has various additives such as a heat stabilizer, an antioxidant, a hydrolysis inhibitor, a crystal nucleating agent, a flame retardant, an antistatic agent, and a release agent as long as the characteristics are not impaired. Further, an ultraviolet absorber or the like may be added.

These additives may be added to the reaction apparatus before the polymerization reaction, may be added to the conveying apparatus or the like from the start of the polymerization reaction to the end of the polymerization reaction, or the product may be removed after the completion of the polymerization reaction. It may be added before delivery. Moreover, you may add to the product after extraction.
When molding the polyester resin of the present invention, in addition to the various additives shown above, glass fiber, carbon fiber, titanium whisker, mica, talc, boron nitride, CaCO ₃ , TiO ₂ , silica, layered silicic acid Crystal nucleating agents such as salt, polyethylene wax and polypropylene wax, reinforcing agents, extenders and the like may be added for molding.

Various inorganic or organic fillers may also be added to the polyester resin of the present invention. Inorganic fillers include anhydrous silica, mica, talc, titanium oxide, calcium carbonate, diatomaceous earth, allophane, bentonite, potassium titanate, zeolite, sepiolite, smectite, kaolin, kaolinite, glass, limestone, carbon, wollastonite. , Calcinated perlite, silicates such as calcium silicate and sodium silicate, hydroxides such as aluminum oxide, magnesium carbonate and calcium hydroxide, salts such as ferric carbonate, zinc oxide, iron oxide, aluminum phosphate and barium sulfate Is mentioned. These may be used individually by 1 type, and may mix and use 2 or more types.

  In the case of a polyester resin containing an inorganic filler, the content of these inorganic fillers in the polyester resin is usually 1% by weight or more, preferably 3% by weight or more, more preferably 5% by weight or more. . Moreover, it is 80 weight% or less normally, Preferably it is 70 weight% or less, More preferably, it is 60 weight% or less.

  Examples of the organic filler include raw starch, modified starch, pulp, chitin / chitosan, coconut shell powder, bamboo powder, bark powder, and powders such as kenaf and straw. Moreover, the nanofiber cellulose etc. which fibrillated fibers, such as a pulp, to a nano level are mentioned. These may be used individually by 1 type, and may mix and use 2 or more types.

In the case of a polyester resin containing an organic filler, the content of these organic fillers in the polyester resin is usually 0.1% by weight or more, preferably 1% by weight or more. Moreover, it is 70 weight% or less normally, Preferably it is 50 weight% or less.
When the content of the inorganic filler and the organic filler in the polyester resin is equal to or higher than the lower limit, the addition effect is sufficiently obtained, and the tensile elongation and impact resistance of the polyester resin are equal to or lower than the upper limit. Tends to be obtained.

  As the crystal nucleating agent, talc, boron nitride, silica, layered silicate, polyethylene wax and polypropylene wax are preferable, and talc and polyethylene wax are more preferable. These may be used individually by 1 type, and may mix and use 2 or more types.

  When the crystal nucleating agent is an inorganic material, the smaller the particle size, the better from the viewpoint of the effect of adding the nucleating agent. The average particle size of the preferred crystal nucleating agent is 5 μm or less, more preferably 3 μm or less, still more preferably 1 μm or less, and most preferably 0.5 μm or less. The lower limit of the average particle size of the crystal nucleating agent is 0.1 μm.

  When a crystal nucleating agent is added to the polyester resin of the present invention, the preferable amount of the crystal nucleating agent is 0.001% by weight or more, more preferably 0.01% by weight or more, and still more preferably 0.001% by weight or more with respect to the polyester resin. 1% by weight or more. Further, the upper limit of the amount of the crystal nucleating agent added is 30% by weight, more preferably 10% by weight, still more preferably 5% by weight, and most preferably 1% by weight with respect to the polyester resin. When the addition amount of the crystal nucleating agent is not less than the above lower limit, the effect of promoting crystallization by adding the crystal nucleating agent can be sufficiently obtained. Moreover, it exists in the tendency for the mechanical physical property and flexibility of a polyester resin to be obtained because it is below the said upper limit.

  Even if not added for the purpose of functioning as a nucleating agent, the purpose of other effects, for example, an inorganic filler added to improve rigidity, an organic stabilizer added as a thermal stabilizer, etc. can also act as a nucleating agent or resin Inorganic or organic foreign matter mixed in the manufacturing process or molding process can also be used as a crystal nucleating agent. Accordingly, the crystal nucleating agent in the present invention corresponds to all inorganic substances and organic substances that are solid at room temperature.

[Use of polyester resin]
The polyester resin of the present invention can be used for molding by various molding methods applied to general-purpose plastics.

Examples of the molding method include compression molding (compression molding, laminate molding, stampable molding), injection molding, extrusion molding, and coextrusion molding (film molding by inflation method and T-die method, laminate molding, pipe molding, electric wire / cable molding. , Profile molding), hollow molding (various blow molding), calendar molding, foam molding (melt foam molding, solid phase foam molding), solid molding (uniaxial stretching molding, biaxial stretching molding, roll rolling molding, stretch oriented nonwoven fabric Examples thereof include molding, thermoforming (vacuum forming, pressure forming), plastic working), powder forming (rotary forming), various non-woven fabric forming (dry method, adhesion method, entanglement method, spunbond method, etc.).

  The polyester resin of the present invention is particularly preferably applied to injection molded articles, extruded molded articles, foam molded articles and hollow molded articles.

  In addition, these molded articles are provided with chemical functions, electrical functions, magnetic functions, mechanical functions, friction / wear / lubricating functions, optical functions, surface functions such as thermal functions, etc. Various secondary processes can also be performed. Examples of secondary processing include embossing, painting, adhesion, printing, metalizing (plating, etc.), machining, surface treatment (antistatic treatment, corona discharge treatment, plasma treatment, photochromism treatment, physical vapor deposition, chemical vapor deposition, Coating) and the like.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples as long as the gist thereof is not exceeded.

  In addition, the measuring methods, such as various physical properties in a following example and a comparative example, are as follows.

<Reduced viscosity>
The polyester resins obtained in Examples and Comparative Examples were dissolved in a mixed solvent of phenol / 1,1,2,2-tetrachloroethane (50 wt% / 50 wt%) at 0.5 g / dl, and an Ubbelohde viscometer was used. And determined from the solution viscosity measured at 30 ° C.

<Polymerization rate>
The reduced viscosity value was determined by dividing by the polymerization time.

<Melting point>
Evaluation was performed by a differential scanning calorimeter. The apparatus was DSC6220 manufactured by SII Nanotechnology, Inc., and the endothermic peak when the temperature was raised at 10 ° C./min was defined as the melting point.

<Tensile test>
The polyester resins obtained in the examples and comparative examples were hot-pressed at a temperature 10-60 ° C. higher than the melting point of the polyester resin by using an MH-10 press machine (ram diameter 40 mmΦ, 160 mm square) manufactured by Imoto Seisakusho. A 200 μm press film was produced. A sample was punched out of the obtained press film into a dumbbell shape, and a tensile test was performed according to JIS K7127 to measure the breaking strength and breaking elongation.

<Light transmittance>
A 200 μm press film obtained in the same manner as in the tensile test was measured with a UV-2500PC UV-visible spectrophotometer manufactured by Shimadzu Corporation, and the light transmittance between wavelengths from 400 nm to 800 nm was measured. And asked.

[Example 1]
In a reaction vessel equipped with a stirrer, a nitrogen inlet, a heating device, a thermometer, and a vacuum port, as raw materials, 62.7 parts by weight of dimethyl 2,5-furandicarboxylate, 48.9 parts by weight of cyclohexanedimethanol, polytetra Irganox 1330 (trade name: manufactured by BASF Japan, 4,4) as an antioxidant and 10.01 parts by weight of methylene glycol (molecular weight 1000), 0.11 parts by weight of a toluene solution in which 6% by weight of tetrabutyl titanate had been dissolved in advance. ', 4 ”-[(2,
4,6-trimethyl-1,3,5-benzenetriyl) tris (methylene)] tris [2,6-bis (
1,1-dimethylethyl) phenol] was charged in an amount of 0.2 parts by weight.

Nitrogen gas was introduced into the reaction vessel, and the inside of the system was changed to a nitrogen atmosphere by vacuum replacement. The temperature was raised to 160 ° C. in 30 minutes, and the reaction was carried out at this temperature for 1 hour. Next, it heated up to 275 degreeC over 1 hour 30 minutes, and was made to react at this temperature for 1 hour. Next, 0.24 parts by weight of a toluene solution in which 6% by weight of tetrabutyl titanate was dissolved in advance was added. Next, the pressure was reduced to 0.2 × 10 ³ Pa or less over 1 hour and 30 minutes, and the polymerization was continued for 2 hours while maintaining the heated and reduced pressure state at 275 ° C. Then, the polymerization was terminated to obtain a polyester resin. .
The polyester resin obtained had a reduced viscosity ηsp / c of 0.985 dL / g and a melting point of 263 ° C. Moreover, the tensile breaking strength of the press film obtained by heat-pressing this polyester resin at 300 ° C. was 52.5 MPa, the breaking elongation was 300%, and the light transmittance was 82.5%.

[Comparative Example 1]
In a reaction vessel similar to that in Example 1, as raw materials, 63.7 parts by weight of dimethyl terephthalate, 47.1 parts by weight of cyclohexanedimethanol, 10.0 parts by weight of polytetramethylene glycol (molecular weight 1000), and tetrabutyl titanate were previously added. 0.59 parts by weight of a 6% by weight toluene solution and 0.2 parts by weight of Irganox 1330 were added as an antioxidant.

Nitrogen gas was introduced into the container, and the inside of the system was changed to a nitrogen atmosphere by vacuum replacement. The temperature was raised to 160 ° C. in 30 minutes, and the reaction was carried out at this temperature for 1 hour. Next, it heated up to 305 degreeC over 1 hour, and was made to react at this temperature for 1 hour. Next, 0.24 parts by weight of a toluene solution in which 6% by weight of titanium tetrabutyrate was dissolved in advance was added. Next, the pressure was reduced to 0.2 × 10 ³ Pa or less over 1 hour and 30 minutes, and the polymerization was continued for 3 hours while maintaining the heated and reduced pressure state at 305 ° C., and then the polymerization was terminated to obtain a polyester resin. .
The polyester resin obtained had a reduced viscosity ηsp / c of 0.323 dL / g and a melting point of 282 ° C. This polyester resin was hot-pressed at 320 ° C., but the molecular weight was too low to form a press film.

[Example 2]
In the same reaction vessel as in Example 1, 27.9 parts by weight of dimethyl 2,5-furandicarboxylate, 13.8 parts by weight of cyclohexanedimethanol, 60.0 parts by weight of polytetramethylene glycol (molecular weight 1000), 0.59 parts by weight of a toluene solution in which 6% by weight of titanium tetrabutyrate is dissolved in advance, and Irganox 1330 (trade name: 4,4 ′, 4 ″-[(2,4, 0.20 part by weight of 6-trimethyl-1,3,5-benzenetriyl) tris (methylene)] tris [2,6-bis (1,1-dimethylethyl) phenol] was charged.

Nitrogen gas was introduced into the reaction vessel, and the inside of the system was changed to a nitrogen atmosphere by vacuum replacement. The temperature was raised to 160 ° C. in 30 minutes, and the reaction was carried out at this temperature for 1 hour. Next, it heated up to 210 degreeC over 1 hour, and was made to react at this temperature for 1 hour. The temperature was further raised to 260 ° C. over 1 hour, and the reaction was carried out at this temperature for 1 hour. Next, 0.19 part by weight of a toluene solution in which 6% by weight of titanium tetrabutyrate was dissolved in advance was added. Next, the pressure was reduced to 0.2 × 10 ³ Pa or less over 1 hour and 30 minutes, the polymerization was continued for 4.5 hours while maintaining the heated and reduced pressure state at 260 ° C., and then the polymerization was terminated. Got.
The polyester resin obtained had a reduced viscosity ηsp / c of 1.867 dL / g and a melting point of 179 ° C. Further, a press film obtained by hot pressing the polyester resin at 210 ° C. has a tensile breaking strength of 20.0 MPa, a breaking elongation of 990%, and a light transmittance of 88.0%.
Met.

[Examples 3 and 4, Comparative Examples 2 to 6]
Polymerization was carried out in the same reaction vessel as in Example 1 at the composition, catalyst amount, and polymerization temperature / time described in Table 1 to obtain polyester resins. Table 1 shows the reduced viscosity, melting point, press temperature, tensile strength at break, elongation at break and light transmittance of the polyester resin obtained.

As shown in Example 1, the polyester resin containing the repeating units represented by the formulas (1) and (2) of the present invention was excellent in the polymerizability, breaking strength and transparency in a well-balanced manner. On the other hand, the polyester resin using the DMT of Comparative Example 1 has a low molecular weight and could not form a press film. Similarly, from Example 2 and Comparative Example 2, Example 3 and Comparative Example 3, and Example 4 and Comparative Example 4, polyesters containing repeating units represented by Formula (1) and Formula (2) of the present invention The resin was shown to be excellent in balance in polymerizability, breaking strength and transparency.
Comparative Example 5 which is a polyester resin not containing the repeating unit represented by the formula (2) of the present invention is a polyester resin having a low elongation at break and having too many repeating units represented by the formula (2) of the present invention. Comparative Example 6 was shown to have low tensile strength at break.

Claims (5)

The ratio of the repeating unit represented by Formula (2) in a polyester resin is 0.5 mol% or more and 50 mol% or less including the repeating unit represented by Formula (1) and Formula (2). Polyester resin characterized by

(1)
[In Formula (1), A represents the group which combined the linear and cyclic aliphatic hydrocarbon group. ]

(2)
[In the formula (2), B represents a polyoxyalkylene group having a number average molecular weight of 200 or more and 6000 or less. ] A in the formula (1) is a group obtained by combining a linear aliphatic hydrocarbon group having 1 to 4 carbon atoms and a cyclic aliphatic hydrocarbon group having 5 to 10 carbon atoms. The polyester resin according to 1. The polyester resin according to claim 1 or 2, wherein the reduced viscosity of the polyester resin is 0.5 dl / g or more. The polyester resin according to claim 1, wherein the polyester resin has a tensile strength at break of 12 MPa or more. The polyester resin according to any one of claims 1 to 4, wherein the light transmittance at a thickness of 200 µm is 75% or more.