JP3279915B2 - Method for producing softened polyester resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a softened polyester resin. The softened polyester resin is useful as a highly transparent soft material replacing the soft vinyl chloride resin.

[0002]

2. Description of the Related Art Polyethylene terephthalate (PET), which is a representative example of aromatic polyester, is used for producing fibers, molding materials, and packaging because of its excellent mechanical strength, thermal properties, humidity properties, transparency, and many other excellent properties. Although it is used in a wide range of fields such as materials and magnetic recording materials, it is not used for wrapping films etc. due to poor flexibility, and soft vinyl chloride is mainly used as a highly transparent soft material. I was

[0003]

However, soft vinyl chloride has problems such as bleeding out of the plasticizer over time and harming the human body. Further, incineration treatment has environmental problems, and a softened polyester resin has been expected as a highly transparent soft material replacing soft vinyl chloride.

As a means for solving these problems, block copolyesters comprising an aliphatic polyester component and an aromatic polyester component have been proposed. However, since the number average molecular weight of the aliphatic polyester is low, a randomization reaction caused by heating during molding has been proposed. The physical properties were significantly reduced due to this.

[0005] It is an object of the present invention to overcome these disadvantages of the prior art and to produce a softened polyester resin which has less plasticizer bleed-out, has flexibility and is a substitute for transparent soft vinyl chloride. Is to provide a way.

[0006]

Means for Solving the Problems The present inventors mainly provide:
It has been found that the above object can be achieved by performing a melt reaction of an aromatic polyester composed of polyethylene terephthalate (PET) and a specific aliphatic polyester,
The present invention has been reached. That is, the present invention mainly
Aromatic polyester consisting of ethylene terephthalate
Polyester resin softened by softening
A method for producing a softened polyester resin, comprising melting the aromatic polyester and an aliphatic polyester having a number average molecular weight of 10,000 to 1,000,000.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The aromatic polyester used in the present invention is mainly composed of polyethylene terephthalate.
It can be obtained by a known method using terephthalic acid and ethylene glycol . Polybasic acids other than terephthalic acid include, for example, isophthalic acid, 2,6
-Naphthalenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenyletherdicarboxylic acid, and the like, and these may be copolymerized in a small proportion. Ethylene glycol
The number 2 or more glycols carbon other than Le, flop <br/> b propylene glycol For example, 1,3-propanediol, 1,
4-butanediol, neopentyl glycol, 1,5
-Pentanediol, 1,6-hexanediol, decamethylene glycol and the like .

The aromatic polyester as described above is 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.

The molecular weight of the aliphatic polyester used in the present invention is, in number average, in the range of 10,000 to 100,000, preferably 25,000 to 80,000, more preferably 40,000 to 70,000. The number average molecular weight of the aliphatic polyester is required to be at least 10,000 or more in order to prevent a decrease in physical properties due to a randomization reaction between the aliphatic polyester and the aromatic polyester. If it is lower than this, the physical properties are significantly reduced due to randomization. Although it is possible to increase the molecular weight by reacting with a chain extender, it is industrially disadvantageous because the steps are multi-step or the used chain extender causes fish eyes in the film. Considering thermal degradation and strength, the number average molecular weight of the aliphatic polyester is preferably 25,000 or more,
000 or more is more preferable. Further, when the number average molecular weight is 10
In order to make it 0000 or more, it takes a long time for the reaction, which is industrially disadvantageous. The number average molecular weight is 100,000 or less, preferably 80,000 or less, and more preferably 70,000 or less, because a long-term reaction increases the volatile matter generated by decomposition or the like.

In order to obtain the aliphatic polyester used in the present invention, (i) a method of polycondensing a polybasic acid (or an ester thereof) with glycol, and (ii) a method of ring-opening polymerization of a cyclic acid anhydride and a cyclic ether. Is mentioned.

Examples of the polybasic acid used in the method (i) include 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, decamethylene glycol and the like. . 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.

In the production of the aliphatic polyester, 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. As a catalyst,
There is no particular limitation 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 usually based on 100 parts by weight of the aliphatic polyester obtained.
It is 0.001 to 5 parts by weight, preferably 0.01 to 0.5 parts by weight.

By the above method (i), an aliphatic polyester having a structural unit consisting of the polybasic acid (or ester thereof) and the glycol is obtained. Among these, in consideration of the melting point, glass transition point, and economy of the obtained aliphatic polyester, an aliphatic polyester having a structural unit consisting of succinic acid and the glycol having 2 or more carbon atoms is preferable, and succinic acid and ethylene are preferable. A structural unit consisting of glycol and / or succinic acid and 1,4
Aliphatic polyesters having a structural unit consisting of butanediol are more preferred.

The cyclic acid anhydride used in the method (ii) includes, for example, succinic anhydride, maleic anhydride, itaconic anhydride, glutaric anhydride, adipic anhydride, citraconic anhydride and the like. As the cyclic ether,
For example, ethylene oxide, propylene oxide, cyclohexene oxide, styrene oxide, epichlorohydrin, allyl glycidyl ether, phenyl glycidyl ether, tetrahydrofuran, oxepane, 1,3-
Dioxolan 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.

By the above method (ii), an aliphatic polyester having a structural unit composed of the cyclic acid anhydride and the cyclic ether is obtained. Among these, the melting point of the aliphatic polyester obtained, the glass transition point, in consideration of economy, aliphatic polyester having a structural unit consisting of succinic anhydride and the cyclic ether is preferable,
Aliphatic polyesters having a structural unit consisting of succinic anhydride and ethylene oxide are more preferred.

Among the methods for obtaining such an aliphatic polyester, as a method that can be industrially and efficiently produced in a relatively short time, the method (ii) of ring-opening polymerization of a cyclic acid anhydride and a cyclic ether is mentioned. More preferred.

Hereinafter, the ring-opening polymerization of the cyclic acid anhydride and the cyclic ether (ii) will be described in more detail.

It has been known that the cyclic acid anhydride such as succinic anhydride used in the method (ii) does not homopolymerize. By cyclically adding cyclic ether in the presence of a polymerization catalyst to such a cyclic acid anhydride that is not homopolymerized and polymerizing, a polyester in which an acid component and an alcohol component are substantially copolymerized alternately can be produced in a short time. Can be generated.

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 batchwise or continuously, and the solvent used in this case includes, for example, 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, 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, tri-iso-propoxygallium,
Tetramethoxygermanium, tetraethoxygermanium, tetra-iso-propoxygermanium, tetra-n-propoxygermanium, tetra-iso-butoxygermanium, tetra-n-butoxygermanium, tetra-sec-butoxygermanium, tetra-
metal alkoxides such as t-butoxygermanium; antimony pentachloride, zinc chloride, lithium bromide, tin chloride (I
V), halides such as cadmium chloride and boron trifluoride diethyl ether; trimethylaluminum, triethylaluminum, diethylaluminum chloride, ethylaluminum dichloride, tri-iso-
Alkyl aluminum such as butyl aluminum; alkyl zinc such as dimethyl zinc, diethyl zinc, diisopropyl zinc; tertiary amine such as triallylamine, triethylamine, tri-n-octylamine, benzyldimethylamine; phosphotungstic acid, phosphomolybdic acid, silica Heteropoly acids such as tungstic acid and alkali metal salts thereof; zirconium oxychloride, zirconyl octylate, zirconyl stearate, zirconium compounds such as zirconyl nitrate and the like, among which zirconyl octylate, tetraalkoxy zirconium,
Trialkoxy aluminum compounds are particularly preferred. The amount of the polymerization catalyst used is not particularly limited, but is usually 0.001 to 1 based on the total amount of the cyclic acid anhydride and the cyclic ether.
0% by weight. 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 determined by the cyclic acid anhydride and the cyclic ether.
There is no particular limitation as long as it is a temperature at which
0 ° C, preferably 50-150 ° C, more preferably 1 ° C
00-150 ° C. During the reaction, the pressure inside the reaction vessel
The force depends on the reaction temperature, the presence or absence of solvent, and the type of solvent.
Pressure increase due to the sequential addition of cyclic ether
The increase in unreacted cyclic ether due to
It is not preferable because the reether component is increased. did
Therefore, the pressure in the reaction vessel is from normal pressure to 50 kgf / cm ^Two Is preferred
And more preferably normal pressure to 15 kgf / cm^Two So that
Add cyclic ether.

The cyclic ether is added in an amount of 3 to 9 per hour per 100 parts by weight of the cyclic 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 a 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 continuously adding the cyclic ether or a method of intermittently adding it in multiple stages. It is preferable to add continuously so that the amount of addition does not largely change over time.

As a preferred embodiment of the above method (ii), specifically, a polymerization vessel is charged in a reaction vessel charged with a cyclic acid anhydride containing succinic anhydride as a main component, which is melted or dissolved in a solvent. When the pressure in the reaction vessel is reduced to 0 in the presence of the catalyst,
while maintaining ^{kgf / cm 2 ~50kgf / cm 2} , sequentially adding a cyclic ether as a main component ethylene oxide in a proportion of 3 to 90 parts by weight per hour relative to the cyclic acid anhydride 100 parts by weight It is preferred to use the ring-opened copolymer aliphatic polyester thus obtained.

The reaction ratio of the cyclic acid anhydride and the cyclic ether in the method (ii) is 40/40 in terms of the molar ratio of these.
The ratio is preferably set to 60 to 60/40. In consideration of the fact that the residual cyclic acid anhydride and the terminal carboxyl group of the aliphatic polyester reduce the physical properties of the polyester, the cyclic ether is added in an excess of 40 to 60/40.
More preferably, the ratio is in the range of / 60 to 49/51. By doing so, less than 50% of the terminal carboxyl groups of the aliphatic polyester become carboxyl groups, and heat resistance is improved. If the ratio is out of the range, the unreacted monomer 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 polyester formed from the polymerization system after the aging reaction may be separated.

When the number average molecular weight of the aliphatic polyester obtained by the methods (i) and (ii) is lower than 10,000, the molecular weight may be further increased by a transesterification reaction or the reaction with various chain extenders. Alternatively, the molecular weight may be increased.

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 Diisocyanate compounds such as diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate; buret polyisocyanate compounds such as Sumidur N (manufactured by Sumitomo Bayer Urethane Co.); IL, HL (manufactured by Bayer AG), Coronate EH (Nippon Polyurethane Industry Co., Ltd.)
Polyisocyanate compound having an isocyanurate ring; adduct polyisocyanate compound such as Sumidur L (manufactured by Sumitomo Bayer Urethane Co., Ltd.); adduct polyisocyanate compound such as Coronate HL (manufactured by Nippon Polyurethane Co., Ltd.) And the like. 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, any 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.

Incidentally, in order to promote the reaction between the aliphatic polyester and the epoxy compound, a known catalyst such as a tertiary amine, a quaternary ammonium salt, an imidazole compound or the like can be freely used, if necessary.

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 and the like can be mentioned. One or more of these can be used.

The amount of the aziridine compound used is 0.001 to 10% by weight, more preferably 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 promote 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 necessary.

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. .

As the metal alkoxide, 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 terminal carboxyl group 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 polyester (metal compound / COOH (molar ratio)) is preferably from 0.1 to 2.0, and more preferably from 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 anhydride is carried out by first subjecting a cyclic acid anhydride and a cyclic ether to ring-opening polymerization, and then reacting the resulting aliphatic polyester with the polyfunctional anhydride. There is a method of simultaneously performing a ring-opening reaction of ether and a polyfunctional acid anhydride, or a method of simultaneously performing a ring-opening reaction of a cyclic acid anhydride, a cyclic ether and a polyfunctional acid anhydride, and further reacting the polyfunctional acid anhydride.

The amount of the polyfunctional acid anhydride is 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 0.001 to 10 with respect to the aliphatic polyester.
%, More preferably 0.01 to 5% 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 melted by heating and melting. And a method of reacting the same.

The softened polyester resin composition of the present invention can be obtained by subjecting the aromatic polyester and the aliphatic polyester thus obtained to a melt reaction.

Examples of the melting reaction include a transesterification reaction and a reaction with various chain extenders. The melting reaction varies depending on various conditions such as the type of aromatic polyester to be reacted, the type of aliphatic polyester, the concentration of the terminal group, the type of chain extender, and the water content in the reaction system. , 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.

The reaction ratio between the aliphatic polyester and the aromatic polyester is not particularly limited, but it is preferable that the weight ratio between the aliphatic polyester and the aromatic polyester be 5/95 to 95/5. If the amount of the aliphatic polyester is less than this range, the effect of softening decreases, which is not preferable. On the other hand, if it exceeds this range, the melting point becomes low, which is not preferable.

The term "softening" as used in the present invention means that a polyester resin obtained by a reaction between an aliphatic polyester and an aromatic polyester has a thickness of 200 μm by a compression molding machine at 260 ° C., 150 kgf / cm ² for 2 minutes. When a film was prepared and the tensile modulus was measured according to ASTM-D882-90 (Method A), the value was 10 to 20,000 kgf / cm.
² , preferably 100 to 10,000 kgf / cm ² . If the tensile modulus is less than 10 kgf / cm ² , it is difficult to handle due to lack of appropriate stiffness. Tensile modulus is 20,000kgf /
If it exceeds cm ² , flexibility is lost and the characteristics as a packaging material are lost.

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

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, and the like may be added to the softened polyester resin thus obtained.
Antistatic 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.

[0060]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the invention is limited thereto. 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., 150 kgf / cm ² ,
A film having a thickness of 200 μm is formed by a compression molding machine under the conditions of 2 minutes, and is subjected to ASTM-D882-90 (Method A).
The breaking strength, the breaking elongation, and the tensile modulus were measured in accordance with the above.

Example 1 In an autoclave, 500.0 parts of succinic anhydride and 4.90 of zirconyl octylate were added.
Was replaced with nitrogen. Next, the temperature of the autoclave was gradually raised to 130 ° C. with stirring to melt the succinic anhydride, and the pressure inside the autoclave was increased to 4.0 to 8.0 at the same temperature.
While maintaining a pressure of 5 kgf / cm ² , 231.1 parts of ethylene oxide were continuously introduced over a period of 4.0 hours at an addition rate of 58 parts per hour. After the ethylene oxide was introduced, an aging reaction was performed at 130 ° C. for 1.0 hour, and then the system was returned to room temperature to obtain a polymerization product. The operation of dissolving the obtained polymerization product in chloroform and performing precipitation purification in tetrahydrofuran was repeated three times to obtain an aliphatic polyester (1). The yield of this aliphatic polyester (1) was 99.2%. The number average molecular weight measured by GPC was 13,500, and the melting point measured by DSC was 101.2.
° C.

25. Obtained aliphatic polyester (1)
0 parts and 75.0 parts of polyethylene terephthalate (Bellepet EFG-7 manufactured by Kanebo Co., Ltd.) are charged into a flask, and placed in a nitrogen stream at a reduced pressure of 0.1 to 0.2 mmHg at 280 ° C.
The reaction was carried out under the conditions described above for 1.0 hour to obtain a softened polyester resin (1).

Example 2 A flask was charged with 85.6 parts of the aliphatic polyester (1) obtained in Example 1 and 85.6 parts of polyethylene terephthalate (Bellepet EFG-7 manufactured by Kanebo KK). 0.1-0.2mm in air flow
The reaction was carried out under a reduced pressure of Hg at 280 ° C. for 1.0 hour,
A softened polyester resin (2) was obtained.

Example 3 12.0 parts of the aliphatic polyester (1) obtained in Example 1 was added to a 50 ml separable flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube, and the atmosphere in the flask was replaced with nitrogen. After three times, a vacuum pump equipped with a trap immersed in dry ice-methanol in a nitrogen stream was used to reduce the temperature to 240 at a reduced pressure of 0.9 to 1.1 mmHg.
The reaction was carried out at a temperature of 2.5 ° C. for 2.5 hours to obtain an aliphatic polyester (2). The number average molecular weight by GPC measurement is 520.
The melting point by DSC measurement was 102.2 ° C.

25. Obtained aliphatic polyester (2)
0 parts and 75.0 parts of polyethylene terephthalate (Bellepet EFG-7 manufactured by Kanebo Co., Ltd.) are charged into a flask, and placed in a nitrogen stream at a reduced pressure of 0.1 to 0.2 mmHg at 280 ° C.
The reaction was carried out under the conditions described above for 1.0 hour to obtain a softened polyester resin (3).

Example 4 40.0 parts of the aliphatic polyester (2) obtained in Example 3 and 60.0 parts of polyethylene terephthalate (Belpet EFG-7 manufactured by Kanebo Co., Ltd.) were charged into a flask, and nitrogen was added. 0.1-0.2mm in air flow
The reaction was carried out under a reduced pressure of Hg at 280 ° C. for 1.5 hours,
A softened polyester resin (4) was obtained.

(Comparative Example 1) A separable flask having a capacity of 200 ml having a thermometer, a stirrer, a nitrogen inlet tube and a diversion cooler was charged with 60.06 parts of succinic anhydride, 37.24 parts of ethylene glycol and 0 parts of zirconyl octylate. .36 parts were added and replaced with nitrogen. Then 106 ~
The reaction was carried out at 170 ° C. for 3.5 hours to obtain a polymerization product. G
The number average molecular weight by PC measurement was 2,100.

The obtained polymerization product (25.0 parts) was mixed with polyethylene terephthalate (Belpet EFG- manufactured by Kanebo Co., Ltd.).
7) 75.0 parts were charged into a flask and placed in a nitrogen stream at 0.
1.0-0.2 mmHg under reduced pressure at 280 ° C.
The reaction was carried out for an hour to obtain a polyester resin (1 ′).

Comparative Example 2 Using polyethylene terephthalate (Belpet EFG-7 manufactured by Kanebo Co., Ltd.), physical properties were compared with the softened polyester resins (1) to (3) of the present invention.

[0073]

[Table 1]

[0074]

[Table 2]

[0075]

According to the present invention, there is no decrease in physical properties due to a randomization reaction caused by heating during molding of a block copolyester comprising an aliphatic polyester component and an aromatic polyester component, and bleed out of a plasticizer is small. ,
A flexible polyester resin having flexibility and replacing transparent soft vinyl chloride can be produced efficiently. The resin can be effectively used for packaging materials, daily necessities and the like.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) C08G 63/00-63/91

Claims (4)

(57) [Claims] 1. A method for producing polyethylene terephthalate,
Flexibility by softening the aromatic polyester
A method for producing a modified polyester resin, comprising:
The aromatic polyester and a number average molecular weight of 10,000 to 10
A method for producing a softened polyester resin, which comprises subjecting a 0000 aliphatic polyester to a melt reaction. (2) 260 softened polyester resin
° C, 150kgf / cm ^Two 2 minutes by compression molding machine
Create a 200 micron thick film, ASTM-D
When the tensile modulus was measured according to 882-90 (Method A)
Value is 10-20,000kgf / cm ^Two Claim 1.
And a method for producing a softened polyester resin. Wherein the aliphatic polyester is mainly a succinic acid or anhydride thereof, according to claim 1 or 2, characterized by having a structural unit consisting of several 2 or more glycols or cyclic ethers carbon Method for producing a softened polyester resin. 4. The pressure in the reaction vessel is increased in the presence of a polymerization catalyst in a reaction vessel in which the aliphatic polyester is charged with a cyclic acid anhydride containing succinic anhydride as a main component, which is melted or dissolved in a solvent. while maintaining the ^{0kgf / cm 2 ~50kgf / cm 2} , 3~ per hour relative to the cyclic acid anhydride 100 parts by weight
The softened polyester resin according to any one of claims 1 to 3, which is a ring-opened copolymer obtained by sequentially adding a cyclic ether containing ethylene oxide as a main component at a ratio of 90 parts by weight. Production method.