JP2002053652A - Biodegradable and recycled polyester resin and production method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biodegradable and recycled polyester resin using a recycled aromatic polyester, being inexpensive and economical and further capable of solving a waste problem by imparting biodegradability to the aromatic polyester conventionally supposed not to have the biodegradability, and a production method thereof. SOLUTION: The biodegradable and recycled polyester resin is produced by imparting the biodegradability to the recycled aromatic polyester (A), and is featured by being produced by reacting an aliphatic polyester (B) having 3,000-300,000 of number-average molecular weight with the recycled aromatic polyester (A) at a reaction ratio (weight ratio) of (A)/(B)=95/5-5/95.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable polyester resin obtained by using a recycled aromatic polyester and a method for producing the same. More specifically, the present invention relates to a biodegradable polyester resin obtained by reacting a recycled aromatic polyester with a specific aliphatic polyester, and a method for producing the same.

[0002]

2. Description of the Related Art Aromatic polyesters are used in a wide range of fields such as fibers, molding materials, packaging materials, and magnetic recording materials because of their excellent mechanical strength, thermal properties, humidity properties, transparency, and many other excellent properties. Due to its excellent characteristics, its demand has been increasing more and more in recent years, and as a result, the amount of the aromatic polyester to be discarded has been rapidly increasing, which has become a social problem.

[0003]

However, aromatic polyesters generally do not have biodegradability and do not rot, resulting in a shortage of landfill sites for landfill disposal, and the incineration of furnaces due to high combustion heat. There are problems such as damage. Attempts have been made to recover and reuse used aromatic polyesters as a solution to these problems, but the number of reuses is naturally limited, and there is no fundamental solution to the fundamental problem of having to dispose of them eventually. Not reached.

[0004] An object of the present invention is to provide an aromatic polyester, which has heretofore been regarded as non-biodegradable, by imparting biodegradability, thereby making it possible to use a recycled aromatic polyester at low cost, economically, and furthermore, to dispose it. Can solve physical problems,
An object of the present invention is to provide a biodegradable recycled polyester resin and a method for producing the same.

[0005]

In order to solve the above-mentioned problems, the present inventor has determined whether or not it is possible to biodegrade the aromatic polyester itself, which is generally regarded as having no biodegradability. We worked diligently.

[0006] First, an attempt was made to blend a biodegradable aliphatic polyester with an aromatic polyester. However, in this case, only the portion of the aliphatic polyester is biodegraded, but the aromatic polyester is not biodegraded, and the fundamental problem has not been solved.

Therefore, it is surprising that when not a mere blend but an aromatic polyester is reacted with an aliphatic polyester by a specific method to form a molecular structure in which the aromatic polyester and the aliphatic polyester are arranged in a block shape. It has been discovered that even the aromatic polyester portion which has been considered not to be biodegradable is biodegraded.

That is, the biodegradable recycled polyester resin according to the present invention is a biodegradable recycled polyester resin obtained by imparting biodegradability to a recycled aromatic polyester (A), In addition to the recycled aromatic polyester (A), an aliphatic polyester (B) having a number average molecular weight of 3,000 to 300,000
As a reaction ratio (weight ratio) (A) / (B) = 95 /
Characterized by being obtained by reacting at 5-5 / 95.
Further, in the method for producing a biodegradable recycled polyester resin according to the present invention, an aliphatic polyester (B) having a number average molecular weight of 3,000 to 300,000 is reacted with a recycled aromatic polyester (A) by a reaction ratio (weight ratio). (A) / (B) = 95/5 to 5/95 and the melting reaction is performed in a heated state.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION As the recycled aromatic polyester (A) used in the present invention, those having a history of passing through a molding machine or a spinning apparatus in a heated and molten state, or virgin generated in a polyester manufacturing facility or the like. Recovered products (recycled products) of the raw materials, and products obtained by further reacting these recovered products (recycled products) with polyfunctional anhydrides such as pyromellitic dianhydride or polyfunctional epoxy compounds. It is preferable to use those recovered products (recycled products) crushed to a size of 0.1 to 20 mm.

The recycled polyester of the aromatic polyester (A) is obtained by a known method mainly using terephthalic acid and a glycol having 2 or more carbon atoms. Examples of polybasic acids other than terephthalic acid include, for example, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenyletherdicarboxylic acid, and the like. These may be copolymerized in a small proportion. Examples of the glycol having 2 or more carbon atoms include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, decamethylene glycol, and the like. Is mentioned. Among these, a combination of terephthalic acid and ethylene glycol and a combination of terephthalic acid and 1,4-butanediol are preferable in consideration of the melting point and economical efficiency of the obtained aromatic polyester.

The aromatic polyesters described above are further copolymerized with one or more trifunctional or higher polyfunctional compounds such as pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, trimethylolpropane and pentaerythritol, if necessary in a small amount. Polyester may be used.

If necessary, the polyester thus obtained may be further reacted with various chain extenders to increase the molecular weight.

The method of reacting with a chain extender involves a multi-step process, an unreacted chain extender adversely affects safety or causes a change in physical properties over time. However, there is an industrial disadvantage in that it causes fisheye of the film. Examples of the chain extender include an isocyanate, an epoxy, an aziridine, an oxazoline, a polyvalent metal compound, a polyfunctional acid anhydride, a phosphoric acid ester, and a phosphite, which will be described later, and may be used alone or in combination of two or more. Is also good.

The aliphatic polyester (B) used in the present invention
The method for producing the aliphatic polyester resin is not particularly limited. Examples of the method for obtaining an aliphatic polyester resin include: (i) a method of polycondensing a polybasic acid (or an ester thereof) with a glycol; )) (Iii) ring-opening polymerization of a cyclic acid anhydride and a cyclic ether, and (iv) ring-opening polymerization of a cyclic ester.

The polybasic acid used in the method (i) includes, for example, succinic acid, adipic acid, suberic acid, sebacic acid, azelaic acid, decanedicarboxylic acid, octadecanedicarboxylic acid, dimer acid and esters thereof. Examples of the glycol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6-hexanediol, and decamethylene glycol. No. It is also possible to use polyoxyalkylene glycol as a part of the glycol component, and examples thereof include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol and copolymers thereof. Among these, a combination of succinic acid and ethylene glycol and / or succinic acid and 1,4-butanediol is preferable in consideration of the melting point, biodegradability, and economy of the aliphatic polyester (B) obtained. In the production of the aliphatic polyester (B), the total amount of the polybasic acid (or its ester) component and the glycol component may be initially mixed and reacted, or may be added in portions as the reaction proceeds. . The polycondensation reaction can be carried out by a usual transesterification method or esterification method, or a combination of the two methods. If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reaction vessel. Usually, a small amount of catalyst needs to be used in the transesterification reaction. The catalyst is not particularly limited as long as it is generally used.
i, Ge, Zn, Fe, Mn, Co, Zr, Hf, V,
Ir, La, Ce, Li, Ca, Mg, Sn, Ba, N
organic metal compounds such as i, organic acid salts, metal alkoxides,
Examples include metal oxides, metal hydroxides, carbonates, phosphates, sulfates, nitrates, and chlorides. The amount of the catalyst used is 0.001 to 5 parts by weight, preferably 100 parts by weight, based on 100 parts by weight of the usually obtained aliphatic polyester (B).
01 to 0.5 parts by weight.

The hydroxycarboxylic acid used in the method (ii) includes, for example, glycolic acid, lactic acid, 3-hydroxypropionic acid, 3-hydroxy-2, 2-dimethylpropionic acid, 3-hydroxy-3-methyl-butyric acid , 4-hydroxybutyric acid, 5-hydroxyvaleric acid, 3-
Examples include hydroxybutyric acid, 3-hydroxyvaleric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid, citric acid, malic acid and esters thereof. As the polycondensation reaction, there is no problem by using a usual transesterification method or esterification method or a combination of both methods. If necessary, the degree of polymerization can be increased by increasing or decreasing the pressure in the reaction vessel.

The cyclic acid anhydride used in the method (iii) includes, for example, succinic anhydride, maleic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride and the like. Examples of the cyclic ether include ethylene oxide, propylene oxide, cyclohexene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, phenyl glycidyl ether, tetrahydrofuran, oxepane, 1,
3-dioxolan and the like. Of these,
Melting point, biodegradability of aliphatic polyester (B) obtained,
Considering economy, a combination of succinic anhydride and ethylene oxide is preferred. The ring-opening polymerization can be carried out using a known ring-opening polymerization catalyst by a method such as polymerization in a solvent or bulk polymerization.

As the cyclic ester used in the method (iv), for example, β-propiolactone, β-methyl-
β-propiolactone, δ-valerolactone, ε-caprolactone, glycolide, lactide and the like.
The ring-opening polymerization can be carried out using a known ring-opening polymerization catalyst by a method such as polymerization in a solvent or bulk polymerization.

Among the methods for obtaining such an aliphatic polyester (B), the method (iii) of ring-opening polymerization of a cyclic acid anhydride and a cyclic ether is one which can be industrially and efficiently produced in a relatively short time. preferable. Hereinafter, the ring-opening polymerization of a cyclic acid anhydride and a cyclic ether will be described in more detail.

It has been known that the cyclic acid anhydride such as succinic anhydride used in the present invention does not homopolymerize. However, by sequentially adding a cyclic ether in the presence of a polymerization catalyst to such a cyclic acid anhydride that is not homopolymerized and polymerizing, an aliphatic component in which an acid component and an alcohol component are substantially copolymerized alternately. Polyester (B) can be formed in a short time.

The polymerization can be carried out by a method such as polymerization in a solvent or bulk polymerization. In polymerization in a solvent, the cyclic acid anhydride is used by dissolving it in a solvent. In bulk polymerization, the cyclic acid anhydride is melted before use in the present invention.

The polymerization in a solvent can be carried out either batchwise or continuously. Examples of the solvent used include benzene, toluene, xylene, cyclohexane, n
-Inert solvents such as hexane, dioxane, chloroform and dichloroethane.

The polymerization catalyst is not particularly limited, and those usually used in ring-opening polymerization of polyester are used. For example, tetramethoxy zirconium, tetraethoxy zirconium, tetra-iso-propoxy zirconium, tetra-iso-butoxy zirconium, tetra-n-butoxy zirconium, tetra-t-butoxy zirconium, triethoxy aluminum, tri-n-propoxy aluminum, tri- iso-propoxyaluminum, tri-n-butoxyaluminum, tri-i
So-butoxyaluminum, tri-sec-butoxyaluminum, mono-sec-butoxy-di-iso-
Propoxy aluminum, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), tetraethoxy titanium, tetra-iso-propoxy titanium, tetra-n-propoxy titanium, tetra-n-butoxy titanium, tetra-se
c-butoxytitanium, tetra-t-butoxytitanium, tri-iso-propoxygallium, tri-iso-propoxyantimony, tri-iso-butoxyantimony, trimethoxyboron, triethoxyboron, triethoxyboron
iso-propoxyboron, tri-n-propoxyboron, tri-iso-butoxyboron, tri-n-butoxyboron, tri-sec-butoxyboron, tri-t-
Butoxyboron, tetramethoxygermanium, tetraethoxygermanium, tetra-iso-propoxygermanium, tetra-n-propoxygermanium, tetra-iso-butoxygermanium, tetra-n-butoxygermanium, tetra-sec-butoxygermanium, tetra-t- Metal alkoxides such as butoxygermanium; halides such as antimony pentachloride, zinc chloride, lithium bromide, tin (IV) chloride, cadmium chloride, boron trifluoride diethyl ether; trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum Dichloride,
Alkylaluminums such as tri-iso-butylaluminum; alkylzincs such as dimethylzinc, diethylzinc, diisopropylzinc; tertiary amines such as triallylamine, triethylamine, tri-n-octylamine, benzyldimethylamine; phosphotungstic acid, phosphorus Heteropoly acids such as molybdic acid and silicotungstic acid and alkali metal salts thereof; zirconium compounds such as zirconium oxychloride, zirconyl octylate, zirconyl stearate, and zirconyl nitrate; and the like, among which zirconyl octylate, tetraalkoxyzirconium, trialkoxy Aluminum compounds are particularly preferred. The amount of the polymerization catalyst used is not particularly limited,
Usually, it is 0.001 to 10% by weight based on the total amount of the cyclic acid anhydride and the cyclic ether. Regarding the method of adding the polymerization catalyst, the polymerization catalyst may be added to the cyclic acid anhydride or may be added sequentially like a cyclic ether.

The polymerization temperature is not particularly limited as long as it is a temperature at which the cyclic acid anhydride reacts with the cyclic ether.
The temperature is 50 ° C, preferably 50 to 150 ° C, and more preferably 100 to 150 ° C. During the reaction, the pressure in the reaction vessel varies depending on the reaction temperature, the presence or absence of a solvent, and the type of solvent.However, the increase in unreacted cyclic ether due to the increase in pressure due to the sequential addition of cyclic ether increases the amount of polyether in the reaction product. It is not preferable because the ether component is increased. Therefore, the pressure in the reaction vessel is preferably normal pressure to 4.90 MPa, more preferably, the cyclic ether is added so as to be normal pressure to 1.47 MPa.

The cyclic ether is added in an amount of 3 to 9 parts per hour per 100 parts by weight of the cyclic acid anhydride.
The amount is preferably 0 parts by weight, more preferably 5 to 50 parts by weight.

If the addition rate of the cyclic ether is lower than the lower limit of 3 parts by weight, the reaction is prolonged and the productivity is lowered, which is not industrially preferable. On the other hand, if it is higher than the upper limit of 90 parts by weight, the polyether component in the reaction product increases and only an aliphatic polyester having a low melting point can be obtained.

The term "sequential addition of the cyclic ether" means that the cyclic ether is not added all at once, and it may be either a method of dropping continuously or a method of intermittent addition in multiple stages. It is preferable to add continuously so that the amount of addition does not largely change over time.

In the present invention, the reaction ratio of the cyclic acid anhydride and the cyclic ether is from 40/60 to 6 in a molar ratio of these.
The ratio is preferably set to 0/40. In view of the fact that the residual cyclic acid anhydride and the terminal carboxyl group of the aliphatic polyester reduce the physical properties of the aliphatic polyester, it is preferable that the cyclic ether be added in excess of 40. / 6
More preferably, the ratio is 0 to 49/51. By doing so, less than 50% of all terminals of the aliphatic polyester are carboxylic acid terminals, and heat resistance is improved.

If the ratio is out of the above range, unreacted monomers may increase and the yield may decrease. In the present invention, it is preferable that after the sequential addition of a predetermined amount of the cyclic ether determined in consideration of the above molar ratio, polymerization is continued at the reaction temperature to ripen. The aliphatic polyester generated from the polymerization system after the aging reaction may be separated.

(I), (ii), (iii), (iv)
If necessary, the aliphatic polyester obtained by any of the above methods may be further increased in molecular weight by a transesterification reaction, or may be reacted with various chain extenders to increase the molecular weight.

The method of reacting with the chain extender may be a multi-step process, an unreacted chain extender may adversely affect safety or cause a change in physical properties over time, However, there is an industrial disadvantage in that it causes fisheye of the film.

Examples of the chain extender include isocyanates, epoxies, aziridines, oxazolines, polyvalent metal compounds, polyfunctional acid anhydrides, phosphoric esters, phosphites, and the like. You may.

The isocyanate compound is not particularly limited, but is preferably a compound having two or more isocyanate groups in one molecule. For example, tolylene diisocyanate (“T
DI), 4,4'-diphenylmethane diisocyanate (also referred to as "MDI"), hexamethylene diisocyanate, xylylene diisocyanate, meta-xylylene diisocyanate, 1,5-naphthalenedi isocyanate, hydrogen Isocyanate compounds such as diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate; and a bullet polyisocyanate compound such as Sumidur N (manufactured by Sumitomo Bayer Urethane Co., Ltd.); Death module IL, HL (Bayer A.
G. FIG. Polyisocyanate compounds having an isocyanurate ring such as Coronate EH (manufactured by Nippon Polyurethane Industry Co., Ltd.); adduct polyisocyanate compounds such as Sumidur L (manufactured by Sumitomo Bayer Urethane Co., Ltd.); Nippon Polyurethane Industry Co., Ltd.)
And adduct polyisocyanate compounds. These can be used alone or in combination of two or more. Further, a block isocyanate may be used.

The reaction ratio between the aliphatic polyester and the isocyanate compound is not particularly limited. For example, the ratio of the isocyanate group of the isocyanate compound to the hydroxyl group of the aliphatic polyester (NCO / OH (molar ratio)) is determined. 0.5 to 3.0, preferably 0.8
More preferably, it is 1.5.

In order to accelerate the urethanization reaction between the aliphatic polyester and the isocyanate compound, a known catalyst such as an organotin compound or a tertiary amine may be used as needed.

The epoxy compound is not particularly limited, but has at least two epoxy groups in the molecule. Examples thereof include (poly) ethylene glycol diglycidyl ether, (poly) propylene glycol diglycidyl ether, and polytetramethylene. Glycol diglycidyl ether, resorcin diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester,
Terephthalic acid diglycidyl ester, hydroquinone diglycidyl ether, bisphenol S diglycidyl ether, glycerol diglycidyl ether, sorbitol polyglycidyl ether, sorbitan polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, Triglycidyl tris (2-hydroxyethyl) isocyanurate, glycerol triglycidyl ether, trimethylolpropane polyglycidyl ether, and the like.

The reaction with the epoxy compound is carried out by first subjecting the cyclic acid anhydride and the cyclic ether to ring-opening polymerization and reacting the resulting aliphatic polyester with the epoxy compound or simultaneously reacting the cyclic acid anhydride with the cyclic ether and the epoxy compound. There is a method in which a ring opening reaction is performed, or a method in which a cyclic acid anhydride, a cyclic ether and an epoxy compound are simultaneously subjected to a ring opening reaction, and further the epoxy compound is reacted.

In order to accelerate the reaction between the aliphatic polyester and the epoxy compound, any known catalyst such as a tertiary amine, a quaternary ammonium salt or an imidazole compound may be used as needed.

The aziridine compound is not particularly limited. For example, 2,2'-bishydroxymethylbutanol-tris [3- (1-aziridinyl) propionate], ethylene glycol-bis [3- (1-aziridinyl) propionate] , Polyethylene glycol-bis [3- (1-aziridinyl) propionate], propylene glycol-bis [3- (1-aziridinyl) propionate], polypropylene glycol-bis [3
-(1-aziridinyl) propionate], tetramethylene glycol-bis [3- (1-aziridinyl) propionate], polytetramethylene glycol-bis [3- (1-aziridinyl) propionate], N,
N'-tetramethylenebisethylene urea, N, N'-pentamethylene bisethylene urea, N, N'-hexamethylene bisethylene urea, N, N'-heptamethylene bisethylene urea, N, N'-octamethylene bis Ethylene urea, N, N'-phenylenebisethylene urea, N, N'-
Toluylene bisethylene urea, N, N'-diphenyl-
4,4'-bisethylene urea, 3,3'-dimethyldiphenyl 4,4'-bisethylene urea, 3,3'-dimethoxydiphenyl 4,4'-bisethylene urea, diphenylmethane p, p-bisethylene urea, etc. Is mentioned. One or more of these can be used.

The amount of the aziridine compound used is preferably from 0.001 to 10% by weight, more preferably from 0.01 to 5% by weight, based on the aliphatic polyester.

The oxazoline compound is not particularly restricted but includes, for example, 2-oxazoline, 2-methyl-2-oxazoline, 2-ethyl-2-oxazoline, 2-isopropyl-2-oxazoline, 2-butyl-2-oxazoline , 2-phenyl-2-oxazoline, 2,2'-
Bis- (2-oxazoline), 2,2'-methylene-bis- (2-oxazoline), 2,2'-ethylene-bis- (2-oxazoline), 2,2'-trimethylene-bis- (2- Oxazoline), 2,2'-tetramethylene-bis- (2-oxazoline), 2,2'-hexamethylene-bis- (2-oxazoline), 2,2'-octamethylene-bis- (2-oxazoline) , 2,2'-ethylene-bis- (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis- (2-oxazoline), 2,2'-m-phenylene-bis -(2-oxazoline), 2,2'-m-phenylene-bis-
(4,4'-dimethyl-2-oxazoline), bis-
(2-oxazolinylcyclohexane) sulfide, bis- (2-oxazolinyl norbornane) sulfide, and the like. One or more of these can be used. More preferably, 2,2'-m-phenylene-bis- (2-oxazoline), bis- (2-
Oxazolinyl norbornane) sulfide.

The reaction ratio between the aliphatic polyester and the oxazoline compound is not particularly limited. For example, the ratio between the 2-oxazoline group (Ox) of the oxazoline compound and the carboxyl group (COOH) of the aliphatic polyester (Ox / COOH) (Molar ratio)) from 0.5 to 10.
0, more preferably 0.8 to 5.0.

In order to accelerate the reaction between the aliphatic polyester and the oxazoline compound, a known catalyst such as an amine salt of an acidic compound may be used as needed.

The polyvalent metal compound is not particularly restricted but includes divalent or higher valent organometallic compounds, metal salts and / or metal alkoxides.

Preferred metals of the divalent or higher valent organometallic compound and / or metal salt include zinc, calcium,
Copper, iron, magnesium, cobalt, barium and the like can be mentioned. More preferably, after neutralization, zinc (II) acetylacetonate, zinc acetate, zinc formate, zinc propionate, zinc carbonate, etc., which can separate and recover the counter anion of the polyvalent metal compound from the reaction system as a volatile component, are mentioned. .

Examples of the metal alkoxide include aluminum isopropoxide, mono-sec-butoxyaluminum diisopropylate, aluminum ethylate, tetraisopropoxytitanium, tetra-n-butoxytitanium,
Examples thereof include tetra (2-ethylhexyloxy) titanium and tetrastearyloxytitanium.

The reaction ratio between the aliphatic polyester and the polyvalent metal compound is not particularly limited. In the case of the neutralization reaction between the carboxyl group at the terminal of the aliphatic polyester and the divalent or higher-valent organometallic compound and / or metal salt, for example, The ratio of the metal compound to the carboxyl group of the aliphatic polyester (metal compound / COOH (molar ratio)) is 0.1 to 2.
It is preferably 0, more preferably 0.2 to 1.2.

In the case of the reaction between the hydroxyl group at the terminal of the aliphatic polyester and the metal alkoxide, for example, the ratio of the metal compound to the hydroxyl group of the aliphatic polyester (metal compound /
OH (molar ratio)) is preferably from 0.1 to 2.0, and more preferably from 0.2 to 1.2.

The polyfunctional acid anhydride is not particularly restricted but includes, for example, pyromellitic dianhydride, benzophenonetetracarboxylic dianhydride, butane-1,2,3,4-tetracarboxylic dianhydride, Maleic acid homopolymer,
Maleic anhydride-vinyl acetate copolymer, maleic anhydride-ethylene copolymer, maleic anhydride-isobutylene copolymer, maleic anhydride-isobutylvinyl ether copolymer, maleic anhydride-acrylonitrile copolymer,
And maleic anhydride-styrene copolymer.

The reaction with a polyfunctional acid anhydride is carried out by first subjecting a cyclic acid anhydride and a cyclic ether to ring-opening polymerization and reacting the resulting aliphatic polyester with the polyfunctional acid anhydride, or There is a method of simultaneously performing a ring-opening reaction between ether and a polyfunctional acid anhydride, or a method of simultaneously performing a ring-opening reaction between a cyclic acid anhydride, a cyclic ether and a polyfunctional anhydride, and further reacting the polyfunctional anhydride.

The amount of the polyfunctional acid anhydride to be used is preferably 0.001 to 10% by weight, more preferably 0.01 to 5% by weight, based on the aliphatic polyester.

The phosphate or phosphite is not particularly limited, but may be a diester or a triester. Examples of the ester group include methyl, ethyl, propyl, butyl, phenyl and 2-ethylhexyl. Methyl, ethyl and phenyl are preferred in consideration of reactivity and economy.

The amount of the phosphoric acid ester or phosphite used is preferably 0.0
0.01 to 10% by weight, more preferably 0.01 to 5% by weight.
% By weight.

The reaction temperature between the chain extender and the aliphatic polyester is preferably from 20 to 250 ° C., more preferably from 100 to 250 ° C.
200 ° C.

The method of reacting the chain extender with the aliphatic polyester is not particularly limited, but a method in which the aliphatic polyester is dissolved in an appropriate solvent and reacted with the chain extender, or a method in which the aliphatic polyester is heated and melted to melt the chain extender. And a method of reacting the same.

It is essential that the aliphatic polyester (B) used in the present invention has a number average molecular weight of 3,000 to 300,000.
200,000, more preferably 40,000 to 15,000
0.

The biodegradable recycled polyester resin of the present application is a recycled aromatic polyester (A)
And a melt reaction of the aliphatic polyester (B) in a heated state. Examples of the melting reaction include a transesterification reaction and a reaction with various chain extenders. The method of reacting with a chain extender involves a multi-step process, an unreacted chain extender adversely affects safety or causes a change in physical properties over time, It is industrially disadvantageous because it causes fish eyes.

In the melting reaction, the aliphatic polyester (B)
The number average molecular weight of the aliphatic polyester (B) is desirably 3,000 or more in order to prevent the physical properties from being reduced by the randomization reaction between the polyester and the aromatic polyester (A). If it is lower than this, the physical properties are significantly reduced due to randomization. In consideration of thermal deterioration and strength, the number average molecular weight of the aliphatic polyester (B) is preferably 25,000 or more, more preferably 40000 or more. On the other hand, if the number average molecular weight exceeds 300,000, the reaction requires a long time, which is industrially disadvantageous. The number average molecular weight is 3000 because the volatile component generated by decomposition or the like increases by reacting for a long time.
00 or less, preferably 200,000 or less, and 150
000 or less is more preferable.

The biodegradable recycled polyester resin of the present application has a molecular structure in which the aromatic polyester (A) and the aliphatic polyester (B) are arranged in a block shape by being obtained by the above melting reaction. What should be done
Until now, the aromatic polyester portion that has not been biodegraded is biodegraded.

By forming a molecular structure in which the aromatic polyester (A) and the aliphatic polyester (B) are arranged in the form of a block, the reason why the aromatic polyester portion which has been considered not to be biodegradable is biodegradable. It is not clear whether this has been done, but the present inventor thinks as follows.

That is, first, the aliphatic polyester (B)
It is considered that among the molecules in which the aromatic polyester (A) and the aromatic polyester (A) are arranged in a block shape, the aliphatic polyester portion is biodegraded, and as a result, the aromatic polyester portion in the molecular order is dispersed. The aromatic polyester portion dispersed in the molecular order is different from the one obtained by simply blending the aliphatic polyester (B) and the aromatic polyester (A). It is thought that it has improved dramatically. Also, when blocking, the aromatic polyester part,
It is expected that the molecular weight has been reduced and the polymer has been incorporated into the block polymer, which has facilitated biodegradation.

In the melting reaction, various types of recycled aromatic polyester (A), types of aliphatic polyester (B), concentration of terminal groups, type of chain extender, moisture content in the reaction system, etc. In general, the reaction is carried out in a nitrogen stream at 150 ° C. or higher, preferably 200 ° C. or higher, more preferably 250 ° C. or higher, either under pressure or under reduced pressure or normal pressure.

Examples of the chain extender include the above-mentioned isocyanates, epoxies, aziridines, oxazolines, polyvalent metal compounds, polyfunctional acid anhydrides, phosphoric esters, phosphites, and the like. May be combined.

[0064] The reaction ratio is not particularly limited in the aliphatic polyester (B) and the aromatic polyester (A), in terms of physical properties, the weight ratio of the aliphatic polyester and an aromatic polyester 5/95 to 95/5 In consideration of biodegradability, the reaction ratio between the aliphatic polyester (B) and the aromatic polyester (A) is 51/4 by weight of the aliphatic polyester and the aromatic polyester.
It is preferably set to 9 to 95/5, more preferably 65/35 to 95/5, and still more preferably 7 to 95/5.
5/25 to 95/5.

The biodegradability that can be expressed by the biodegradable recycled polyester resin of the present invention is, as a biodegradation rate calculated by a biodegradation test described in Examples described below, preferably 20% or more after 36 months. More preferably, it is 40% or more after 24 months.

In order to obtain the biodegradable recycled polyester resin of the present invention, a known apparatus can be used.

Examples of the vertical reactor include a reactor having a helical ribbon blade and a spirally deformed baffle.

Examples of the horizontal reactor include a horizontal single-shaft or twin-shaft kneader in which stirring shafts connected to deformed blades are arranged side by side.

A batch type or a continuous type may be used.
Examples of the batch type include a Max Blend blade type reactor (manufactured by Sumitomo Heavy Industries, Ltd.), a super blend blade type reactor (Sumitomo Heavy Industries, Ltd.), and an inverted conical ribbon blade type reactor (Mitsubishi Heavy Industries, Ltd.) Manufactured by Hitachi Ltd.) and a twisted lattice blade type reactor (manufactured by Hitachi, Ltd.).
For continuous type, for example, by Volak (Sumitomo Heavy Industries, Ltd.)
Hitachi Glass Wing Polymerizer (manufactured by Hitachi, Ltd.), Hitachi Lattice Wing Polymerizer (manufactured by Hitachi, Ltd.), self-cleaning reactor (manufactured by Mitsubishi Heavy Industries, Ltd.), horizontal two-shaft reactor ( One shaft or two widely used for KRC kneader (manufactured by Kurimoto Iron Works), TEX-K (manufactured by Nippon Steel Works, Ltd.), extrusion molding or devolatilization of plastics, etc. A shaft extruder can be used. In particular, among these, it is most preferable to use a twin-screw kneading apparatus in order to cause a melt reaction between the aliphatic polyester (B) and the recycled aromatic polyester (A).

In the present invention, the aliphatic polyester
(B) and aromatic polyester (A).
260 ° C, 1470 N / c
m^Two0.2mm thickness by compression molding machine under the condition of 2 minutes
And a film of ASTM-D882-90 (A
Method when the tensile modulus is measured according to
0.98-9800 N / mm^Two, More preferably
9.8-980 N / mm^TwoAnd even more preferably 98
~ 980 N / mm^TwoIt is. Tensile modulus is 0.98N /
mm^TwoIf the value is less than
No. Tensile modulus is 9800N / mm ^TwoIf it exceeds
It loses its flexibility and loses its characteristics as a packaging material.

A phosphorus compound, a sulfur ester compound, a hindered phenol compound, and a hindered amine compound may be added as needed to suppress or prevent a randomization reaction between the aliphatic polyester (B) and the aromatic polyester (A). it can.

The biodegradable recycled polyester resin thus obtained may contain, if necessary, other components such as a nucleating agent, a pigment, a dye, a heat-resistant agent, an antioxidant, a weather-resistant agent, a lubricant, an antistatic agent. Agents, stabilizers, fillers, reinforcing materials, flame retardants, plasticizers, and other polymers can be added as long as the effects of the present invention are not impaired.

The biodegradable recycled polyester resin of the present invention comprises an unreacted recycled aromatic polyester (A), aliphatic polyester (B), or an additive such as the above-mentioned nucleating agent. It can be used in the form of a polyester resin composition used in combination within a range that does not impair the effects of the present invention. At that time, the proportion of the biodegradable recycled polyester resin in the polyester resin composition is preferably 80% by weight or more, more preferably 90% by weight or more.

Since the biodegradable recycled polyester resin of the present invention has a low environmental load and good moldability, it can be applied to ordinary molding methods such as extrusion molding, injection molding, hollow molding and vacuum molding. And molded articles such as various parts, containers, materials, instruments, films, sheets, fibers and the like.

[0075]

EXAMPLES The present invention will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to these examples. The parts in the examples represent parts by weight. The evaluation methods performed in the examples are as follows. The results are summarized in Tables 1 and 2.

(Molecular Weight) The number average molecular weight in terms of polystyrene was measured using a gel permeation chromatograph.

(Melting point) DSC (S made by Seiko Denshi Kogyo KK)
Using an SC5200 type), 20 mg of the sample was melted and held at 280 ° C. for 5 minutes under a nitrogen stream, and then rapidly cooled with liquid nitrogen. The endothermic peak temperature based on the melting of the crystal during the process of raising the temperature of the sample at a rate of 6 ° C./min was defined as the melting point.

(Tensile test) 260 ° C., 1470 N / cm
^2. A film having a thickness of 0.2 mm was prepared by a compression molding machine under the conditions of 2 minutes and ASTM-D882-90 (Method A).
The breaking strength, the breaking elongation, and the tensile modulus were measured in accordance with the above.

(Biodegradability test) 260 ° C., 1470 N /
cm ² , thickness 0.2m by compression molding machine under the condition of 2 minutes
m was prepared. The obtained film was buried in a planter charged with soil and sprinkled once a day.
The sample was stored in a thermo-hygrostat at 65 ° C. and a relative humidity of 65%. The film was taken out at predetermined time intervals, washed with water, dried on the surface of water, weighed, and the biodegradation rate was calculated by the following equation.

The soil used was one collected from Onohara, Minoh-shi and Nishiburi-cho, Suita-shi, and one obtained by mixing humus in a ratio of 3: 1: 3. Biodegradation rate (%) = film weight after predetermined time / film weight before embedding (Example 1) In a 1 liter autoclave, 216.0 parts of succinic anhydride, 108.0 parts of toluene and a zirconyl octylate solution (containing zirconium) Rate 12% by weight)
2.47 parts were added and the atmosphere was replaced with nitrogen. Then, the temperature of the autoclave was gradually raised to 130 ° C. with stirring to melt succinic anhydride, and the pressure in the autoclave was reduced to 0.
While maintaining the pressure at 29 to 0.82 MPa, ethylene oxide 1
3. Add 33.1 parts at an addition rate of 26.6 parts per hour.
Introduced continuously over 0 hours. After the ethylene oxide was introduced, an aging reaction was performed at 130 ° C. for 1.0 hour, and then the internal temperature was raised to 1
While maintaining the temperature at 30 ° C., the system was returned to normal pressure. After nitrogen blowing, the pressure in the system was reduced to 133 Pa to obtain an aliphatic polyester (1). The number average molecular weight by GPC measurement was 16,400, and the melting point by DSC was 98 ° C.

The aliphatic polyester (1) obtained 75.
0 parts and 25.0 parts of the recycled aromatic polyester (1) (manufactured by Yono PET Bottle Recycle Co., Ltd.) are charged into a flask, and heated at 280 ° C. under a reduced pressure of 13.3 to 26.6 Pa in a nitrogen stream. The reaction was carried out under the conditions for 1.0 hour to obtain a biodegradable recycled polyester resin (1).

When the biodegradability of the biodegradable recycled polyester resin (1) was measured, it was 10
The biodegradation rate was 0%. As a result, it was found that not only the aliphatic polyester (1) but also the aromatic polyester (1) was biodegraded.

(Example 2) 67.0 parts of the aliphatic polyester (1) obtained in Example 1 and 33.0 parts of the recycled aromatic polyester (1) (produced by Yono PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (2).

(Example 3) 51.0 parts of the aliphatic polyester (1) obtained in Example 1 and 49.0 parts of the recycled aromatic polyester (1) (manufactured by Yonon PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (3).

(Example 4) 25.0 parts of the aliphatic polyester (1) obtained in Example 1 and 75.0 parts of the recycled aromatic polyester (1) (manufactured by Yono PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (4).

Example 5 To a 100-liter autoclave were added 35.2 parts of succinic anhydride, 17.1 parts of toluene and 0.401 part of a zirconyl octylate solution (zirconium content: 12% by weight), and the atmosphere was replaced with nitrogen. Was.
Then, the temperature of the autoclave was gradually raised to 130 ° C. with stirring to melt succinic anhydride, and the pressure inside the autoclave was maintained at 0.29 to 0.66 MPa at the same temperature.
17.82 parts of ethylene oxide were introduced continuously over a period of 5.0 hours at a rate of 3.56 parts per hour. After the ethylene oxide was introduced, an aging reaction was performed at 130 ° C. for 1.0 hour, then the system was returned to normal pressure while maintaining the internal temperature at 130 ° C., and after blowing nitrogen, the toluene was devolatilized.
The pressure was reduced to obtain a polymerization product. The number average molecular weight by GPC measurement was 18,000, and the melting point by DSC was 98 ° C.

Subsequently, 50.0 parts of the obtained polymerization product was transferred to another 100 LSUS reactor under nitrogen, 1.14 parts of hexamethylene diisocyanate was added, and the mixture was reacted at a jacket temperature of 180 ° C. for 1.5 hours. Then, an aliphatic polyester (5) was obtained. The number average molecular weight measured by GPC was 72,000.

The aliphatic polyester (5) obtained 75.
0 parts and 25.0 parts of the recycled aromatic polyester (1) (manufactured by Yono PET Bottle Recycle Co., Ltd.) are charged into a flask, and heated at 280 ° C. under a reduced pressure of 13.3 to 26.6 Pa in a nitrogen stream. The reaction was carried out under the conditions for 1.0 hour to obtain a biodegradable recycled polyester resin (5).

(Example 6) 67.0 parts of the aliphatic polyester (5) obtained in Example 5 and 33.0 parts of the recycled aromatic polyester (1) (manufactured by Yono PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (6).

Example 7 300.0 parts of succinic anhydride (manufactured by Lonza, purity 99.8) was placed in a 1-liter autoclave equipped with a high-viscosity stirrer, which had been thoroughly purged with nitrogen and dried.
%) And 1.643 parts of zirconocene dichloride (manufactured by Tokyo Kasei Kogyo Co., Ltd., purity: 97% or more), followed by purging with nitrogen. The autoclave is then slowly stirred for 1 hour.
The temperature was raised to 30 ° C. to melt succinic anhydride, and while maintaining the pressure in the autoclave at 0.29 to 0.66 MPa at the same temperature, 158.6 parts of ethylene oxide (purity: 99.9, manufactured by Nippon Shokubai Co., Ltd.) %) Was introduced continuously over 10.0 hours at an addition rate of 15.9 parts per hour.
After introducing ethylene oxide, an aging reaction was performed at 130 ° C. for 1.5 hours, and then the system was returned to normal pressure while maintaining the internal temperature at 130 ° C., to obtain an aliphatic polyester (7). GP
The number average molecular weight by C measurement was 28,000, and the melting point by DSC was 94.4 ° C.

The obtained aliphatic polyester (7) 67.
0 parts and 33.0 parts of the recycled aromatic polyester (1) (manufactured by Yonon PET Bottle Recycle Co., Ltd.) are charged into a flask, and heated at 280 ° C. under a reduced pressure of 13.3 to 26.6 Pa in a nitrogen stream. The reaction was carried out under the conditions for 1.0 hour to obtain a biodegradable recycled polyester resin (7).

When the biodegradability of the biodegradable recycled polyester resin (7) was measured, it was found that the biodegradability was 10 months after 36 months.
The biodegradation rate was 0%. As a result, it was found that not only the aliphatic polyester (7) but also the aromatic polyester (1) was biodegraded.

(Example 8) 51.0 parts of the aliphatic polyester (7) obtained in Example 7 and 49.0 parts of the recycled aromatic polyester (1) (manufactured by Yonon PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (8).

(Example 9) 300.0 parts of succinic anhydride (manufactured by Lonza Co., purity 99.8) was placed in a 1-liter autoclave equipped with a high-viscosity stirrer, which had been sufficiently purged with nitrogen and dried.
%), 1.45 parts of filtered zirconyl octylate after dehydration and drying with calcium hydride (Daiichi Kagaku Kagaku Kogyo Co., Ltd., acid content: 0.008 mol% based on succinic anhydride)
Below, water content: 0.02 mol% with respect to succinic anhydride
The following), and 30 parts of cyclohexane dried with molecular sieves were added, and the atmosphere was replaced with nitrogen. Then, the temperature of the autoclave was gradually raised to 130 ° C. with stirring to melt succinic anhydride, and 145.36 parts of ethylene oxide (Japan Catalyst, purity 99.9%) was continuously introduced over 6.5 hours at an addition rate of 22.36 parts per hour. 1 after introduction of ethylene oxide
After aging at 30 ° C. for 1.5 hours, the internal temperature was increased to 130 ° C.
The system was returned to normal pressure while maintaining the temperature at 0 ° C., and after blowing nitrogen, cyclohexane was devolatilized and the pressure in the system was reduced to 133 Pa to obtain an aliphatic polyester (9). The number average molecular weight by GPC measurement was 42,300, and the melting point by DSC was 104.2 ° C.

The obtained aliphatic polyester (9) 67.
0 parts and 33.0 parts of the recycled aromatic polyester (1) (manufactured by Yonon PET Bottle Recycle Co., Ltd.) are charged into a flask, and heated at 280 ° C. under a reduced pressure of 13.3 to 26.6 Pa in a nitrogen stream. The reaction was carried out under the conditions for 1.0 hour to obtain a biodegradable recycled polyester resin (9).

When the biodegradation rate of the biodegradable recycled polyester resin (9) was measured, it was found that the biodegradability was 10 months after 36 months.
The biodegradation rate was 0%. As a result, it was found that not only the aliphatic polyester (9) but also the aromatic polyester (1) was biodegraded.

(Example 10) 51.0 parts of the aliphatic polyester (9) obtained in Example 9 and 49.0 parts of the recycled aromatic polyester (1) (produced by Yonon PET Bottle Recycle Co., Ltd.) Was charged into a flask, and reacted under a reduced pressure of 13.3 to 26.6 Pa at 280 ° C. for 1.0 hour in a nitrogen stream to obtain a biodegradable recycled polyester resin (10).

(Comparative Example 1) 3.0 parts of the aliphatic polyester (1) obtained in Example 1 and the recycled aromatic polyester (1) (Yono PET Bottle Recycle Co., Ltd.)
97.0 parts was charged into a flask, and 1
1. Under a reduced pressure of 3.3 to 26.6 Pa and a condition of 280 ° C.
The reaction was carried out for 0 hour to obtain a comparative polyester resin (1).

(Comparative Example 2) In Comparative Example 1, no aliphatic polyester (1) was used as the polyester.
Comparative polyester resin (2) was obtained in the same manner as in Comparative example 1 except that only the recycled aromatic polyester (1) was used.

[0100]

[Table 1]

[0101]

[Table 2]

[0102]

According to the present invention, it is possible to impart biodegradability to an aromatic polyester which has heretofore been regarded as having no biodegradability, and it is inexpensive and economical to use a recycled aromatic polyester. Can provide a highly biodegradable recycled polyester resin, and can be effectively used for packaging materials, daily necessities and the like. Further, the biodegradation can solve the waste problem.

Continued on the front page F-term (reference) 4J029 AA01 AC03 AC05 AD01 AD10 BA02 BA03 BA04 BA05 BA08 BA10 BF25 BF30 CA02 CA04 CA06 CB06 CC06 CF08 CF15 DB13 EA00 EA02 EA03 EA05 EG02 EG07 EG09 EH01 EH02 FC05 J08J1J01 J01 J02 JF141 JF161 JF181 JF281 JF291 JF321 JF331 JF341 JF361 JF421 JF541 JF561 JF571 JF581 KE05

Claims (5)

[Claims] 1. A biodegradable recycled polyester resin obtained by imparting biodegradability to a recycled aromatic polyester (A), wherein the recycled aromatic polyester (A) has a number average The aliphatic polyester (B) having a molecular weight of 3,000 to 300,000 is converted into a reaction ratio (weight ratio) of (A) / (B).
A biodegradable recycled polyester resin obtained by reacting at 95/5 to 5/95. 2. The method according to claim 1, wherein the aliphatic polyester (B) is obtained from an aliphatic dicarboxylic acid component having 2 to 6 carbon atoms and an aliphatic glycol component having 2 to 4 carbon atoms. Biodegradable recycled polyester resin. 3. The aliphatic polyester (B) is obtained by ring-opening copolymerization of a cyclic acid anhydride (C) containing succinic anhydride as a main component and a cyclic ether (D) containing ethylene oxide as a main component. The biodegradable recycled polyester resin according to claim 1 or 2, wherein 4. The biodegradable recycled polyester according to claim 1, wherein the recycled aromatic polyester (A) and the aliphatic polyester (B) are arranged in a block shape. resin. 5. The recycled aromatic polyester (A) is mixed with an aliphatic polyester (B) having a number average molecular weight of 3,000 to 300,000 as a reaction ratio (weight ratio) of (A) / (B) = 95/5. A method for producing a biodegradable recycled polyester resin, wherein a melt reaction is performed in a heated state at 5/95.