JP2020158683A - Ricinoleic acid ester copolymer - Google Patents

Abstract

To provide a ricinoleic acid ester copolymer improved in biodegradability.SOLUTION: There is provided a copolymer (A) satisfying the following requirements (A1) to (A4): (A1) containing a constitutional unit (a) derived from ricinoleic acid, a constitutional unit (b) derived from an aliphatic dicarboxylic acid and a constitutional unit (c) derived from a diol having 2 to 10 carbon atoms, (A2) when the total of the constitutional units (a), (b) and (c) is defined as 100 mol%, the content of the constitutional unit (a) is 20 to 90 mol%, the content of the constitutional unit (b) is 5 to 40 mol% and the content of the constitutional unit (c) is 5 to 40 mol%, (A3) the terminal group amount of the constitutional unit (a) is 0.70 or more; the terminal group amount of the constitutional unit (a)/the total terminal group amount (the terminal group amount of the constitutional unit (a)+the terminal group amount of the constitutional unit (b)+the terminal group amount of the constitutional unit (c)) and (A4) the intrinsic viscosity [IV] is in the range of 0.1 to 2.0 dl/g.SELECTED DRAWING: None

Description

The present invention relates to a ricinoleic acid ester copolymer having good biodegradability.

In recent years, interest in environmental protection has been increasing, and the promotion of purchasing environmentally friendly materials by the Green Purchasing Law and the promotion of recycling of plastic materials and electrical appliances by the Containers and Packaging Recycling Law and the Home Appliance Recycling Law are manifested. In such a series of trends, expectations for biodegradable polymers with low environmental impact are increasing day by day.

In addition, most of the lubricating oils used in machines, not limited to plastic materials, are manufactured based on mineral oil, but in general, mineral oil is difficult to decompose in nature and may remain for a long period of time. There is a demand for lubricating oils that are easily decomposed and have less impact on the ecosystem.

As the biodegradable polymer, polyesters such as polylactic acid, which is a polyester of hydroxy acids such as lactic acid and ricinoleic acid, polyricinoleic acid, and polyesters of an aliphatic dicarboxylic acid and a diol are known.

For example, thermoplastic biodegradation consisting of an aliphatic dicarboxylic acid or ester, an aliphatic or alicyclic diol, a naturally occurring unsaturated acid or ester thereof, and a branching agent selected from molecules having at least three functional groups. Lubricating oil composition containing a lubricating oil additive (Patent Document 2) composed of an aliphatic copolyester (Patent Document 1), a ricinolic acid, a copolymerized polyester with an aliphatic dicarboxylic acid and a diol, or a polyricinolic acid. (Patent Document 3) and the like have been proposed.

However, it has been found that the polyester copolymer containing ricinoleic acid is still not sufficiently biodegradable.

Japanese Patent Publication No. 2005-523357 International Publication No. 2017/038734 Pamphlet International Publication No. 2009/148110 Pamphlet

An object of the present invention is to obtain a ricinoleic acid ester copolymer having improved biodegradability.

That is, the present invention
The present invention relates to a ricinoleic acid ester copolymer (A) that satisfies the following requirements (A1) to (A4).
(A1) Includes a structural unit (a) derived from ricinoleic acid, a structural unit (b) derived from an aliphatic dicarboxylic acid, and a structural unit (c) derived from a diol having 2 to 10 carbon atoms;
(A2) When the total of the structural units (a), (b) and (c) is 100 mol%, the content of the structural unit (a) is 20 to 90 mol% and the content of the structural unit (b). Is 5 to 40 mol%, and the content of the structural unit (c) is 5 to 40 mol%;
(A3) The amount of the terminal group of the structural unit (a) is 0.70 or more;
The amount of terminal groups of the structural unit (a) / the amount of all terminal groups (the amount of terminal groups of the structural unit (a) + the amount of terminal groups of the structural unit (b) + the amount of terminal groups of the structural unit (c))
(A4) The ultimate viscosity [IV] is in the range of 0.1 to 2.0 dl / g.

Since the ricinoleic acid ester copolymer (A) of the present invention is excellent in biodegradability, for example, it is possible to provide a viscosity modifier capable of reducing the environmental load.

[Ricinoleic acid ester copolymer (A)]
Ricinoleic acid ester copolymerization (A) according to the present invention [Hereinafter, it may be abbreviated as "copolymer (A)". ] Are copolymers and polyester copolymers that satisfy the following requirements (A1) to (A4).

<Requirements (A1)>
It contains a structural unit (a) derived from ricinoleic acid, a structural unit (b) derived from an aliphatic dicarboxylic acid, and a structural unit (c) derived from a diol having 2 to 10 carbon atoms.

[Constituent unit derived from ricinoleic acid (a)]
The structural unit (a) derived from ricinoleic acid in the present invention (hereinafter, may be simply referred to as “constituent unit (a)”) is ricinoleic acid (12-hydroxy-cis-9-octadecenoic acid) or ricinol. It is a structural unit derived from an acid derivative. In the present invention, high biodegradability can be expected when the copolymer (A) contains such a structural unit (a).

Examples of the derivative of ricinoleic acid include a condensate of ricinoleic acid, an esterified product of ricinoleic acid and carboxylic acid, an esterified product of ricinoleic acid and alcohols (for example, ricinoleic acid methyl ester), and a reaction product of ricinoleic acid and an epoxy compound. , 12-Hydroxystearic acid obtained by hydrogenating ricinoleic acid and its condensate, esterified product of 12-hydroxystearic acid and carboxylic acid or alcohols (for example, 12-hydroxystearic acid methyl ester), etc. to ricinoleic acid by polymerization reaction Examples include various compounds that give the building block (a) from which it is derived.

In the present specification, the monomer component corresponding to the structural unit (a), that is, the above-mentioned ricinoleic acid and the derivative of ricinoleic acid may be referred to as "monomer component (a')".
As described above, since the derivative of ricinoleic acid also includes 12-hydroxystearic acid and its ester, the structural unit (a) referred to in the present invention is specifically the following formula (1) or the following. It is a structural unit represented by the formula (2).

Here, the ratio of the total of the structural units derived from 12-hydroxystearic acid and its ester derivative to the total structural unit (a), that is, the configuration represented by the above formula (2) in the total structural unit (a). The ratio of the total of the units is not particularly limited, and the total of the structural units (a) derived from ricinolic acid (that is, the structural unit represented by the above formula (1) and the structural unit represented by the above formula (2) Is arbitrary in the range of 0 to 100 mol%, where 100 mol% is taken as the total. However, in the present invention, since it tends to be easy to obtain a lubricating oil composition having high transparency and high low temperature fluidity, the structural unit (a) derived from ricinoleic acid is represented by the above formula (1). It is preferable to include a structural unit. In that sense, the above ratio is preferably 0 to 80 mol%, more preferably 0 to 60 mol%. By being in the above preferable range, it is excellent in terms of fluidity at low temperature and dispersibility in base oil (particularly vegetable oil). However, when the lubricating oil composition of the present invention is used for applications that do not necessarily require high transparency, for example, when it is used for grease or the like, the above ratio does not necessarily have to be in the above preferable range, and for example, It is not excluded that the structural unit (a) derived from ricinoleic acid is composed of only the structural unit represented by the above formula (2).

[Constituent unit derived from aliphatic dicarboxylic acid (b)]
The structural unit (b) derived from the aliphatic dicarboxylic acid (hereinafter, may be simply referred to as “constituent unit (b)”) is derived from the aliphatic dicarboxylic acid or the aliphatic dicarboxylic acid ester. Specifically, the structural unit (b) referred to in the present invention is a structural unit having a structure in which −OH is removed from the two carboxyl groups contained in the aliphatic dicarboxylic acid formally.

It is preferable that the aliphatic dicarboxylic acid that leads to the structural unit (b) is aliphatic because it does not reduce the biodegradability of the obtained copolymer.
The aliphatic dicarboxylic acid is not particularly limited as long as it does not have a functional group having reactivity in the system in which the ester polymerization reaction is carried out, for example, a hydroxyl group, and one type alone or two or more types may be combined. Specifically, malonic acid (3 carbon atoms), dimethylmalonic acid (5 carbon atoms), succinic acid (4 carbon atoms), glutaric acid (5 carbon atoms), adipic acid (6 carbon atoms). , 2-Methyladipic acid (7 carbon atoms), trimethyladiponic acid (9 carbon atoms), Pimeric acid (7 carbon atoms), 2,2-dimethylglutaric acid (7 carbon atoms), 3,3- Examples thereof include diethyl succinic acid (8 carbon atoms), suberic acid (8 carbon atoms), azelaic acid (9 carbon atoms), and sebacic acid (10 carbon atoms). On the other hand, examples of the aliphatic dicarboxylic acid ester include various esters of the above-mentioned aliphatic dicarboxylic acid.

Of these, an aliphatic dicarboxylic acid having 6 to 12 carbon atoms is preferable, and sebacic acid is particularly preferable.
In the present specification, the monomer component corresponding to the constituent unit (b), that is, the aliphatic dicarboxylic acid and the aliphatic dicarboxylic acid ester may be referred to as "aliphatic dicarboxylic acid component (b')". ..

[Constituent unit (c) derived from a diol having 2 to 10 carbon atoms]
Specifically, the structural unit (c) derived from a diol having 2 to 10 carbon atoms (hereinafter, may be simply referred to as “constituent unit (c)”) is formally formally having 2 to 10 carbon atoms. It is a structural unit having a structure in which −H is removed from the two hydroxyl groups contained in the diol. The diol having 2 to 10 carbon atoms that leads to the structural unit (c) may be used alone or in combination of two or more, and specific examples thereof include the following compounds.

Examples of the diol having 2 to 10 carbon atoms include an aliphatic diol having 2 to 10 carbon atoms. Examples of such aliphatic diols are 1,2-ethanediol (ethylene glycol: 2 carbon atoms), 1,3-propanediol (trimethylethylene glycol: 3 carbon atoms), 1,2-propanediol (1,2-propanediol). Propropylene glycol: 3 carbon atoms), 1,4-butanediol (tetramethylene glycol: 4 carbon atoms), 2,2-dimethylpropane-1,3-diol (neopentyl glycol: 5 carbon atoms), 1 , 6-Hexanediol (hexamethylene glycol: 6 carbon atoms), 1,8-octanediol (octamethylene glycol: 8 carbon atoms), 1,9-nonanediol (nonamethylene glycol: 9 carbon atoms), etc. Can be mentioned.

Among such aliphatic diols, the side chain alkyl group-containing glycols include 2-methyl-1,3-propanediol, 2-ethyl-1,3-propanediol, 2-hexyl-1,3-propanediol, and the like. 2-Hexil-1,6-propanediol, neopentyl glycol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-n Examples thereof include −butyl-1,3-propanediol, 1,3-nonanediol, 2-methyl-1,8-octanediol, and the like.

Among the above diols, 1,4-butanediol is particularly preferable.
In the present specification, the monomer component corresponding to the structural unit (c), that is, the diol having 2 to 10 carbon atoms is sometimes referred to as "diol component (c')".
As described above, the copolymer (A) used in the present invention also contains the above-mentioned structural units (b) and (c) in addition to the above-mentioned structural unit (a).

[Other building blocks]
The copolymer (A) used in the present invention is preferably composed of only the above-mentioned structural units (a) to (c), but the above-mentioned structural unit (a) is used as long as the effects of the present invention are not impaired. A structural unit that does not fall under any of (c) (hereinafter, “other structural unit”) may be further included.
Other building blocks include frangylcarboxylic acids such as 2,5-frangicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, alicyclic dicarboxylic acids such as 1,3-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, and 2 -Constituent units derived from various dicarboxylic acids and carboxylic acid esters that do not correspond to the above aliphatic dicarboxylic acid component (b'), such as aromatic dicarboxylic acids such as methylterephthalic acid and naphthalenedicarboxylic acid, and have 11 or more carbon atoms. Constituent units derived from aliphatic diols, structural units derived from aromatic diols, trihydric or higher polyvalent alcohols such as trimethylolethane and glycerin, trivalent or higher polyvalent carboxylic acids such as butanetricarboxylic acid and trimellitic acid. Examples thereof include acids and oxydicarboxylic acids such as 4-hydroxyphthalic acid.

In the present specification, the monomer component corresponding to "other constituent units", that is, various dicarboxylic acids and carboxylic acid esters not corresponding to the above-mentioned aliphatic dicarboxylic acid component (b'), and 11 carbon atoms. The above aliphatic diols, aromatic diols, trivalent or higher polyvalent alcohols, trivalent or higher polyvalent carboxylic acids, oxydicarboxylic acids and the like may be referred to as "other monomer components".

<Requirements (A2)>
When the total of the structural units (a), (b) and (c) is 100 mol%, the content of the structural unit (a) is 20 to 90 mol%, preferably 30 to 90 mol%. The content of (b) is 5 to 40 mol%, preferably 5 to 35 mol%, and the content of the structural unit (c) is 5 to 40 mol%, preferably 5 to 35 mol%.

As described above, the lower limit of the content of the structural unit (a) is 20 mol%, but 30 mol% is more preferable, 40 mol% is further preferable, and 50 mol% is particularly preferable. It is preferable that the content of the structural unit (a) is 20 mol% or more from the viewpoint of imparting appropriate stickiness. When it is 30 mol% or more, it is more preferable in terms of improving the viscosity characteristics of the obtained composition and the storage stability, that is, the turbidity (haze) of the base oil. Storage stability is particularly preferred when it is 40 mol% or more. Shear stability is also preferred. On the other hand, the upper limit of the content of the structural unit (a) is 90 mol%, but 85 mol% is more preferable. The content of the structural unit (a) is preferably 90 mol% or less in terms of heat resistance and adhesiveness of the obtained composition. Based on these, the content of the structural unit (a) is preferably 40 to 90 mol%, more preferably 45 to 85 mol%.

Further, the molar ratio ((b) / (c)) of the structural unit (b) to the structural unit (c) is preferably 0.9 to 1.1.
In the production method described later, the above range can be adjusted by changing the ratio of introducing ricinoleic acid or a ricinoleic acid derivative, an aliphatic dicarboxylic acid and a diol having 2 to 10 carbon atoms into the polymerization system.

As described above, the copolymer (A) according to the present invention is preferably composed of only the above-mentioned structural units (a) to (c), but contains other structural units as long as the effects of the present invention are not impaired. You may be. When the copolymer (A) contains other structural units, the content of the other structural units in the copolymer (A) is 100, which is the sum of the above structural units (a) to (c) and the other structural units. The mol% is preferably 20 mol% or less, more preferably 10 mol% or less, and particularly preferably 5 mol% or less.
The contents of the above-mentioned structural units (a) to (c) and "other structural units" in the copolymer (A) can be determined by an appropriate method such as NMR.

<Requirements (A3)>
The amount of the terminal group of the structural unit (a) is 0.70 or more, preferably 0.80 or more, and more preferably 0.90 or more;
Amount of terminal groups in structural unit (a) / amount of all terminal groups (amount of terminal groups in structural unit (a) + amount of terminal groups in structural unit (b) + amount of terminal groups in structural unit (c)) ≥ 0.70
Since the copolymer (A) of the present invention is a polyester composed of ricinolic acid, an aliphatic dicarboxylic acid, and a diol, the terminal group of the copolymer (A) is a structural unit (a) derived from ricinolic acid. It is either a structural unit (b) derived from an aliphatic dicarboxylic acid or a structural unit (c) derived from a diol having 2 to 10 carbon atoms.

Therefore, all the terminal group amounts in the copolymer (A) are the total amount of the terminal group amount of the structural unit (a) + the terminal group amount of the structural unit (b) + the terminal group amount of the structural unit (c). ..
A copolymer in which the amount of the terminal group of the structural unit (a) is less than 0.70 is inferior in biodegradability.

<Requirements (A4)>
The ultimate viscosity [IV] is in the range of 0.1 to 2.0 dl / g. It is preferably 0.1 to 1.5 dl / g, more preferably 0.2 to 1.5 dl / g, still more preferably 0.2 to 1.0 dl / g, and particularly preferably 0.2 to 0.6 dl / g. Is. Within the above range, the workability of the copolymer is excellent, and the resulting composition is excellent in shear stability and various physical properties.

The copolymer (A) is a compound that derives the constituent units (a), (b) and (c), that is, the monomer component (a') and the aliphatic dicarboxylic acid component (b'). And the above diol component (c') can be obtained by carrying out an ester polymerization reaction under the condition of a charge amount in which (a') is four times or more that of (c'). That is, the above-mentioned ricinol acid or ricinol acid derivative in the above section "Constituent unit derived from ricinol acid (a)" and the above-mentioned aliphatic dicarboxylic acid or the above-mentioned aliphatic dicarboxylic acid in the above "Constituent unit derived from aliphatic dicarboxylic acid (b)". The aliphatic dicarboxylic acid ester and the diol having 2 to 10 carbon atoms described above in the above section "Constituent unit (c) derived from a diol having 2 to 10 carbon atoms" in (a') is (c'). It is obtained by subjecting them to ester polymerization reaction with each other under the condition of a charge amount of 4 times or more. This ester polymerization reaction is subjected to the various dicarboxylic acids, carboxylic acid esters, aliphatic diols having 11 or more carbon atoms, aromatic diols, trivalent or higher polyvalent alcohols, and trivalent or higher, which are described in the above section “Other constituent units”. When carried out in the coexistence of the polyvalent carboxylic acid, oxydicarboxylic acid and the like, the copolymer (A) containing "other constituent units" can be obtained.

As a production method, conventionally known methods such as a direct esterification method and a transesterification method can be applied.
In the direct esterification method, the above-mentioned monomer component (a'), the above-mentioned aliphatic dicarboxylic acid component (b'), the above-mentioned diol component (c') and the above-mentioned optional "other monomer component" are subjected to a conventional method. A copolymer can be obtained by direct polycondensation. For example
With the above monomer component (a')
With the dicarboxylic acid component (the aliphatic dicarboxylic acid component (b') described above, and the various dicarboxylic acids described above in the section "Other constituent units").
The temperature of the diol (the diol component (c') and the various diols described in the above section "Other constituent units") is raised under pressure, and the generated condensed water is removed from the reaction system to form a low molecular weight condensation. After the product, the reaction system is depressurized in the presence of a polycondensation catalyst such as a titanium compound, a germanium compound, or an antimony compound to distill off the diol from the system. This makes it possible to produce a high molecular weight polyester resin. In this example, the case where the above-mentioned monomer component (a') is reacted with the dicarboxylic acid component and the diol is mentioned, but as the above-mentioned "other monomer component", a trihydric or higher polyhydric alcohol and / Alternatively, the same can be performed when a polyvalent carboxylic acid having a valence of 3 or more coexists.

Further, in the transesterification method, a corresponding dialkyl ester of a dicarboxylic acid may be used as a starting material. In this case, the corresponding dialkyl ester is adopted as the aliphatic dicarboxylic acid component (b'), and the monomer component (a'), the diol component (c') and the optional "other simple" are used. A copolymer can be obtained by directly polycondensing with the "mer component" by a conventional method. At this time, the above-mentioned monomer component (a') and / or the various dicarboxylic acids described in the above-mentioned section “Other constituent units” may also be used in the form of corresponding alkyl esters. For example
With the above monomer component (a')
Dialkyl esters of dicarboxylic acids (the aliphatic dicarboxylic acid component (b') described above, and the various dicarboxylic acids described above in the section "Other building blocks").
The diol (the diol component (c') and the various diols described in the above section "Other constituent units") are heated at normal pressure to remove the generated alkyl alcohol from the reaction system, and the condensation has a low molecular weight. After the product, the reaction system is depressurized in the presence of a polycondensation catalyst such as a titanium compound, a germanium compound, or an antimony compound to distill off the diol from the system. This makes it possible to produce a high molecular weight polyester resin. In this example, the case where the above-mentioned monomer component (a') is reacted with a dialkyl ester of a dicarboxylic acid and a diol was mentioned, but as the above-mentioned "other monomer component", a trihydric or higher polyhydric alcohol The same can be performed when and / or a trivalent or higher-valent polycarboxylic acid coexists.

Although the esterification reaction in the direct esterification method and the transesterification method proceeds without a catalyst, it is preferable to use a polycondensation catalyst as exemplified above.
In both the direct esterification method and the transesterification method, in order to keep the reaction system in a uniform liquid state, the reaction system is heated so that the reaction temperature does not fall below the melting points of the oligomer and polyester produced. It is preferable to proceed with the reaction. If it is necessary to further increase the molecular weight (weight average molecular weight), the copolymerized polyester resin obtained by melt polymerization can be subjected to solid phase polymerization to increase the molecular weight.

The copolymer (A) of the present invention can also be produced by an ester polymerization reaction with lipase. In this method, the monomer component (a'), the aliphatic dicarboxylic acid component (b'), the diol component (c') and the optional "other monomer component" are added in the presence of lipase. A copolymer can be obtained by polycondensation. As the lipase, an immobilized lipase derived from Burkholderia cepacia (for example, Lipase PS-C Amano II (trade name), PS-D Amano I (trade name), etc. manufactured by Wako Chemical Co., Ltd.) is preferable, and in this case, the temperature is high. However, since lipase is not easily deactivated, the reaction temperature can be raised to 90 ° C. Further, as the reaction conditions, it is preferable to use a batch method using a reactor with a stirrer under bulk conditions. The reaction time varies depending on conditions such as catalyst concentration and polymerization temperature, but is usually 4 to 7 days.

Further, the ester polymerization reaction is a reversible reaction, and it is preferable to sequentially remove the produced alcohol and water in order to proceed with the efficient polymerization reaction. Specifically, the pressure state in the reaction system is maintained in a reduced pressure state, or a hygroscopic agent such as synthetic zeolite (for example, molecular sieve 4A) is installed in the reaction system in a non-contact manner before carrying out the synthetic reaction. Can be mentioned. By carrying out the polymerization reaction under such conditions, the polymerization reaction can be carried out simply and easily, and the copolymer (A) can be efficiently synthesized.

In the present invention, the above-mentioned monomer component (a'), the above-mentioned aliphatic dicarboxylic acid component (b'), the above-mentioned diol component (c') and the above-mentioned optional "other monomer component" in each of the above ester polymerization reactions. The ratio of the charged amount of "" can be appropriately adjusted according to the contents of the above-mentioned structural units (a), (b), (c) and "other structural units" to be achieved in the copolymer (A). ..

The copolymer obtained by the ester polymerization reaction as described above may be adopted as the copolymer (A) as it is, but further, a hydrogenation reaction may be carried out by using a conventionally known suitable method. Therefore, hydrogenation may be performed on a part or all of the double bonds contained in the above-mentioned structural unit (a). For example, first, a copolymer (A0) containing the structural unit represented by the above formula (1) as the structural unit (a) of the copolymer (A) is prepared by an ester polymerization reaction, and then the copolymer (A0) is prepared. The copolymer (A0) may be partially or completely hydrolyzed, or the product obtained by such watering may be adopted as the copolymer (A).

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.
[Physical properties of copolymer]
<Composition of copolymer>
The composition of the copolymer was analyzed by the following procedure.
1) An ECA500 type nuclear magnetic resonance apparatus manufactured by JEOL Ltd. was used, and deuterated chloroform was used as a solvent. The sample concentration was 35 mg / 0.5 mL, and the measurement temperature was 50 ° C.
The observation nucleus is ¹ H (500 MHz), the sequence is a single pulse, the pulse width is 6.3 μsec (45 ° pulse), the repetition time is 8.5 seconds, the number of integrations is 394, and the hydrogen signal of tetramethylsilane is chemical. It was measured as a reference value for the shift. Each peak was assigned by a conventional method.
2) The obtained measurement data was analyzed, the carboxylic acid and alcohol components constituting the polyester were identified, and their composition ratios were determined.

<Terminal group amount>
The obtained measurement data was analyzed, and the terminal group ratios of each were determined from the integrated values of the characteristic signals of ricinoleic acid and diol. For the aliphatic dicarboxylic acid, the sample was modified with trichloroacetylisocyanic acid and then measured in the same manner as above using a nuclear magnetic resonance apparatus to determine the terminal group ratio. The amount of each terminal group was calculated by dividing the determined terminal group ratio by the total of the terminal group ratios of ricinoleic acid, aliphatic dicarboxylic acid, and diol.

[Biodegradability]
The biodegradation rate was measured according to the modified MITI test method "OECD301C". The Eco Mark certification standard revised in July 1998 requires that the biodegradation rate be 60% or more.

<Ultimate viscosity (IV)>
The obtained polyester was dissolved in a mixed solvent having a mass ratio of phenol and 1,1,2,2-tetrachloroethane of 1: 1 to prepare a solution. The number of seconds of flow of the obtained solution at 25 ° C. was measured using an Ubbelohde viscometer, and the ultimate viscosity was calculated by applying the following formula.
[Η] = ηSP / [C (1 + KηSP)]
[Η]: Extreme viscosity (dl / g)
ηSP: Specific viscosity C: Sample concentration (g / dl)
K: The straight line of the graph when the specific viscosity ηSP of samples with different sample concentrations C (3 points or more) is measured based on the following formula, and the sample concentration C is plotted on the horizontal axis and ηSP / C is plotted on the vertical axis. Tilt)
t: Number of seconds (seconds) of flow of the sample solution
t0: Number of seconds for solvent to flow (seconds)
ηSP = (t−t0) / t0

[Example 1]
Tetraethylammonium methyl 13.8 kg (63.0 parts by mass), sebacic acid 4.5 kg (20.4 parts by mass), 1,4-butanediol 3.4 kg (15.5 parts by mass) 8.1 g (0.04 parts by mass) of a 20 wt% aqueous solution of tetraethylammonium hydroxide was added, and the temperature was raised from room temperature to 200 ° C. over 30 minutes. After reaching 200 ° C., stirring was started and kept at 200 ° C. for 5.0 hours to carry out an esterification reaction.

After the esterification reaction is completed, the solution is transferred to a polycondensation reaction tank, 0.26 kg (1.2 parts by mass) of titanium tetrabutoxide is added at 200 ° C., the pressure is reduced to 6.6 Torr over 60 minutes, and polycondensation is performed. The reaction was carried out for 9.0 hours. After completing the polycondensation reaction and flowing nitrogen to return the inside of the system to normal pressure, the copolymer (A-1) was withdrawn from the reaction vessel within 10 minutes.

As a result of measuring the physical properties of the obtained copolymer (A-1) by the method described above, the composition of the copolymer (A-1) was such that the amount of the structural unit derived from methyl ricinolate was 49 mol%. The amount of the structural unit derived from sebacic acid is 24 mol%, and the amount of the structural unit derived from 1,4-butanediol is 27 mol%, and the amount of the terminal group derived from methyl ricinolate with respect to the total amount of terminal groups. The ratio was 0.84, the ultimate viscosity (IV) was 0.31 g / dl, and the biodegradation rate was 88%.

[Comparative Example 1]
To the esterification reaction tank Tetratetraethyl in 13.2 kg (60.2 parts by mass) of ricinoleic acid, 4.5 kg (20.5 parts by mass) of sebacic acid, 3.7 kg (16.9 parts by mass) of 1,4-butanediol. 8.1 g (0.04 parts by mass) of a 20 wt% aqueous solution of ammonium hydroxide was added, and the temperature was raised from room temperature to 200 ° C. over 30 minutes. After reaching 200 ° C., 0.06 kg (0.3 parts by mass) of titanium tetrabutoxide was added 3 hours later, and the mixture was kept as it was at 200 ° C. for 2 hours to carry out an esterification reaction.

After completion of the esterification reaction, the solution was transferred to a polycondensation reaction tank, 0.45 kg (2.0 parts by mass) of titanium tetrabutoxide was added at 200 ° C., the pressure was reduced to 5.8 Torr or less over 60 minutes, and the weight was increased. The condensation reaction was carried out for 4.0 hours. After completing the polycondensation reaction and flowing nitrogen to return the inside of the system to normal pressure, the copolymer (B-1) was withdrawn from the reaction vessel within 10 minutes.

As a result of measuring the physical properties of the obtained copolymer (B-1) by the method described above, the composition of the copolymer (B-1) was such that the amount of the structural unit derived from ricinolic acid was 48 mol% and sebacin. The amount of constituent units derived from acid is 24 mol%, and the amount of constituent units derived from 1,4-butanediol is 28 mol%, and the ratio of the amount of terminal groups derived from ricinol acid to the total amount of terminal groups is It was 0.48, the ultimate viscosity (IV) was 0.24 g / dl, and the biodegradation rate was 63%.

[Comparative Example 2]
Tetraethylammonium methyl 4.8 kg (60.0 parts by mass), sebacic acid 1.6 kg (19.4 parts by mass), 1,4-butanediol 1.6 kg (20.3 parts by mass) 2.9 kg (0.04 parts by mass) of a 20 wt% aqueous solution of tetraethylammonium hydroxide was added, and the temperature was raised from room temperature to 200 ° C. over 30 minutes. After reaching 200 ° C., stirring was started and kept at 200 ° C. for 5.0 hours to carry out an esterification reaction.

After the esterification reaction is completed, the solution is transferred to a polycondensation reaction tank, 0.02 kg (0.2 parts by mass) of titanium tetrabutoxide is added at 200 ° C., the pressure is reduced to 2.0 Torr over 60 minutes, and polycondensation is performed. The reaction was carried out for 5.5 hours. After completing the polycondensation reaction and flowing nitrogen to return the inside of the system to normal pressure, the copolymer (B-2) was withdrawn from the reaction vessel within 10 minutes.

As a result of measuring the physical properties of the obtained copolymer (B-2) by the method described above, the composition of the copolymer (B-2) was such that the amount of the structural unit derived from methyl ricinolate was 49 mol%. The amount of the structural unit derived from sebacic acid is 24 mol%, and the amount of the structural unit derived from 1,4-butanediol is 27 mol%, and the amount of the terminal group derived from methyl ricinolate with respect to the total amount of terminal groups. The ratio was 0.65, the ultimate viscosity (IV) was 0.27 g / dl, and the biodegradation rate was 68%.

[Comparative Example 3]
Tetraethylammonium methyl 4.8 kg (60.0 parts by mass), sebacic acid 1.6 kg (19.4 parts by mass), 1,4-butanediol 1.6 kg (20.3 parts by mass) 2.9 g (0.04 parts by mass) of a 20 wt% aqueous solution of tetraethylammonium hydroxide was added, and the temperature was raised from room temperature to 200 ° C. over 30 minutes. After reaching 200 ° C., stirring was started and kept at 200 ° C. for 5.0 hours to carry out an esterification reaction.

After completion of the esterification reaction, the solution was transferred to a polycondensation reaction tank, 0.02 kg (0.22 parts by mass) of titanium tetrabutoxide was added at 200 ° C., the pressure was reduced to 0.3 Torr or less over 60 minutes, and the weight was increased. The condensation reaction was carried out for 6.5 hours. After completing the polycondensation reaction and flowing nitrogen to return the inside of the system to normal pressure, the copolymer (B-3) was withdrawn from the reaction vessel within 10 minutes.

As a result of measuring the physical properties of the obtained copolymer (B-3) by the method described above, the composition of the copolymer (B-3) was such that the amount of the structural unit derived from methyl ricinolate was 50 mol%. The amount of the structural unit derived from sebacic acid is 23 mol%, and the amount of the structural unit derived from 1,4-butanediol is 27 mol%, and the amount of the terminal group derived from methyl ricinolate with respect to the total amount of terminal groups. The ratio was 0.48, the ultimate viscosity (IV) was 0.26 g / dl, and the biodegradation rate was 53%.

According to the present invention, since the ricinoleic acid ester copolymer (A) is excellent in biodegradability, for example, it is possible to provide a viscosity modifier capable of reducing the environmental load.

Claims (1)

Copolymer (A) satisfying the following requirements (A1) to (A4):
(A1) Includes a structural unit (a) derived from ricinoleic acid, a structural unit (b) derived from an aliphatic dicarboxylic acid, and a structural unit (c) derived from a diol having 2 to 10 carbon atoms;
(A2) When the total of the structural units (a), (b) and (c) is 100 mol%, the content of the structural unit (a) is 20 to 90 mol% and the content of the structural unit (b). Is 5 to 40 mol%, and the content of the structural unit (c) is 5 to 40 mol%;
(A3) The amount of the terminal group of the structural unit (a) is 0.70 or more;
The amount of terminal groups of the structural unit (a) / the amount of all terminal groups (the amount of terminal groups of the structural unit (a) + the amount of terminal groups of the structural unit (b) + the amount of terminal groups of the structural unit (c))
(A4) The ultimate viscosity [IV] is in the range of 0.1 to 2.0 dl / g.