JP2014005369A - Polylactic acid-based polyester resin, polylactic acid-based polyester resin water dispersion, and production method of polylactic acid-based polyester resin water dispersion - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a polylactic acid-based polyester resin which has a self-emulsifying function that can form an aqueous emulsion without using an emulsifier and an organic solvent and which has a high biomass degree; a water dispersion resin composition including the same; an aqueous adhesive composition; a water color ink; a laminate formed by using the aqueous adhesive/the water color ink; a packaging material; and a production method of the water dispersion.SOLUTION: A polylactic acid-based polyester resin is characterized by satisfying following formulas (1), (2) and (3), and a water dispersion including the polyester resin, an aqueous resin composition, an aqueous adhesive, a water color ink laminate and a packaging material are disclosed. 1≤Log(MV)≤4 (1), 300≤(AV)≤2,000 (2), Log(MV)≤0.0028×(AV)+1.2 (3), where MV is a melt viscosity (Pa s) of the resin at 80°C, and AV is a carboxyl group acid number (eq/t) in the resin.

Description

  The present invention relates to a polylactic acid-based polyester resin having a self-emulsifying function capable of forming a stable aqueous emulsion without using an emulsifier and an organic solvent, and having a resin skeleton derived from plant raw materials, and a polyester resin containing the same The present invention relates to an aqueous dispersion and a method for producing the aqueous dispersion.

  In recent years, paints, inks, coating agents, adhesives, pressure-sensitive adhesives, sealants, primers, and various processing agents for textile products and paper products have been changed from conventional organic solvent systems to water-based, high solids from the viewpoint of suppressing emissions of volatile organic solvents. It is progressing in the direction of pulverization and pulverization. In particular, water-based dispersion using an aqueous dispersion is regarded as the most versatile and promising in terms of workability and work environment improvement. In addition, if the binder component forming the aqueous dispersion is mainly composed of a biodegradable resin, it is more preferable from the viewpoint of preventing environmental pollution after disposal. In addition, if the binder component forming the water dispersion is manufactured using biomass-derived components such as animals and plants as raw materials, it is more preferable in terms of reducing carbon dioxide emissions than those using fossil fuels as raw materials.

  The polylactic acid-based resin is a resin mainly composed of plant-derived components that can be produced using lactic acid and / or lactide as raw materials, which can be produced using plants such as corn and potato as raw materials. Polylactic acid-based resins are biodegradable to be decomposed into water and carbon dioxide within several years in soil and seawater, and have a relatively low environmental load when released into the environment. Therefore, if the polylactic acid-based resin can be made into an aqueous dispersion, it is useful as a binder component having biodegradability and using biomass-derived components as raw materials, and paints, inks, coating agents, adhesives, and pressure-sensitive adhesives. It can be expected that it can be used for sealing agents, primers, and various treating agents for textile products and paper products.

  Examples of using a resin containing a polylactic acid segment as a binder component after being dispersed in water include Patent Documents 1 to 5. In Patent Documents 1 and 2, a polylactic acid aqueous dispersion forcedly emulsified with an emulsifier is used. Although the water-based polylactic acid shown in Patent Document 3 is also forcibly emulsified using an emulsifier, it is shown that a hydrophilic group may be introduced into the resin. The sodium salt of 5-sulfoisophthalic acid or the sodium salt of dimethyl 5-sulfoisophthalic acid is preferred. Patent Document 4 discloses a copolymer polyurethane having a polylactic acid segment and a sulfonic acid metal base-containing segment in the molecule, and has a self-emulsifying function capable of forming a stable aqueous emulsion without adding an emulsifier. It has been shown. In Patent Document 5, a lactic acid-based polymer having a hydroxyl group is reacted with a polyvalent carboxylic acid or an acid anhydride thereof, the lactic acid-based polymer is dissolved in an organic solvent, a base and water are added, and phase-inversion emulsification is performed, thereby self-water dispersibility. The process for producing the particles is shown.

JP 2008-13657 A JP 2008-13658 A JP 2003-277595 A JP 2010-174170 A JP 2000-7789 A

  When the present inventors examined the background art, it was found that there were the following problems. That is, in the inventions disclosed in Patent Documents 1, 2, and 3, since an emulsifier is used when preparing a polylactic acid resin aqueous dispersion, when used as a binder component, the emulsifier is attached to the resin. There exists a subject that it remains in the interface of a body and reduces adhesiveness. In addition, in the invention disclosed in Patent Document 4, stable water dispersion is obtained without using an emulsifier, and when used as a binder component, it exhibits high adhesion, but in the production process of the water dispersion. Solvent removal operation is performed, and there is room for improvement from the viewpoint of suppressing volatile organic solvent emissions. Also in the invention disclosed in Patent Document 5, the solvent removal operation is performed in the production process of the aqueous dispersion, and there is room for improvement from the viewpoint of suppressing emission of volatile organic solvents.

  The present invention has been made against the background of such prior art problems. That is, the problem to be solved by the present invention is a polylactic acid-based polyester resin having a self-emulsifying function capable of forming an aqueous emulsion without using an emulsifier and an organic solvent, and having a high degree of biomass. An object of the present invention is to provide an aqueous dispersion resin composition, an aqueous adhesive composition, an aqueous ink, a laminate formed of an aqueous adhesive / aqueous ink, a packaging material, and a method for producing an aqueous dispersion.

As a result of intensive studies, the present inventors have found that the above problems can be solved by the following means, and have reached the present invention. That is, this invention consists of the following structures.
<1> A polylactic acid-based polyester resin characterized by satisfying the formulas (1), (2), and (3).
1 ≦ Log (MV) ≦ 4 (1)
300 ≦ (AV) ≦ 2,500 (2)
Log (MV) ≦ 0.0028 × (AV) +1.2 (3)
However, MV is the melt viscosity (Pa · s) of the polylactic acid-based polyester resin at 80 ° C., and AV is the acid value (eq / t) of the polylactic acid-based polyester resin.
<2> The polylactic acid-based polyester resin according to <1>, wherein the lactic acid content is 40% by weight or more.
<3> The polylactic acid-based polyester resin according to <1> or <2>, wherein the number average molecular weight is 2,000 or more and 50,000 or less.
<4> A polylactic acid-based polyester resin aqueous dispersion containing the polylactic acid-based polyester resin according to any one of <1> to <3>, a basic compound, and water.
<5> The polylactic acid-based polyester resin aqueous dispersion according to <4>, which does not contain a surfactant.
<6> The polylactic acid-based polyester resin aqueous dispersion described in <4> or <5>, which does not contain an organic solvent.
<7> Polylactic acid-based polyester resin water dispersion by mixing the polylactic acid-based polyester resin according to any one of <1> to <3>, a basic compound, and water without adding a surfactant and an organic solvent. A method for producing an aqueous dispersion of a polylactic acid-based polyester resin, comprising a step of obtaining a body.
<8> An aqueous resin composition comprising the polylactic acid-based polyester resin according to any one of <1> to <3> and a curing agent having reactivity with a carboxyl group.
<9> The aqueous resin composition according to <8>, wherein the curing agent is one or more selected from the group consisting of a polyvalent epoxy compound, an oxazoline resin, a carbodiimide resin, and a polyvalent metal salt. .
<10> An aqueous adhesive comprising the aqueous resin composition according to <8> or <9>.
<11> A water-based ink comprising the water-based resin composition of <8> or <9> and a color material.
<12> A layer (A layer) made of the polylactic acid-based polyester resin according to any one of <1> to <3> and a layer (B layer) selected from the group consisting of a film, a sheet, a woven fabric, a nonwoven fabric, and paper A laminate comprising:
<13> The laminate according to <12>, wherein the B layer is mainly composed of a biomass-derived material and / or a chemically modified material of the biomass-derived material.
<14> A packaging material having the laminate according to <12> or <13> as a constituent element.

  Since the polylactic acid-based polyester resin of the present invention contains a polylactic acid segment at a high concentration, the degree of biomass is high and the biodegradability is excellent. In addition, since the polylactic acid-based polyester resin of the present invention has a high concentration of carboxyl groups in the molecular chain, it can be easily dispersed in water simply by stirring with an aqueous solution of a basic compound without using an emulsifier and an organic solvent. Exhibits excellent water dispersibility. Moreover, since the polylactic acid-type polyester resin aqueous dispersion of this invention can be prepared without using an emulsifier, it is excellent in adhesiveness. Furthermore, the adhesive layer and ink which are excellent in adhesiveness and water resistance can be obtained easily by mix | blending the hardening | curing agent which has reactivity with respect to a carboxyl group in the polylactic acid-type polyester resin aqueous dispersion of this invention. Moreover, a laminated body with a high biomass degree can be obtained by combining various biomass materials and the adhesive and / or ink of the present invention.

It is the graph which plotted the relationship between AV and Log (MV) of the polylactic acid-type polyester resin used by the Example and the comparative example.

The polylactic acid-type polyester resin of this invention is a polylactic acid-type polyester resin characterized by satisfy | filling following formula (1), (2), (3).
1 ≦ Log (MV) ≦ 4 (1)
300 ≦ (AV) ≦ 2,500 (2)
Log (MV) ≦ 0.0028 × (AV) +1.2 (3)
However, MV is the melt viscosity (Pa · s) of the resin at 80 ° C., and AV is the acid value (eq / t) in the resin.

  The greatest feature of the polylactic acid-based polyester resin of the present invention is that an aqueous dispersion can be easily formed only by stirring with an aqueous solution of a basic compound without using an emulsifier and an organic solvent. Although it can be easily imagined that the water-dispersibility of a resin having a high concentration of hydrophilic groups tends to be high, the resin actually exhibits water dispersibility only by having a high concentration of hydrophilic groups. Not exclusively. The present inventors have found that it is important that the resin has sufficiently high mobility at the temperature at which the resin is dispersed in water. If the mobility of the resin is low, most of the hydrophilic groups continue to exist in a state separated from water inside the resin mass, and the effect of improving the water dispersibility of the resin is not exhibited. On the other hand, if the resin is sufficiently plasticized at the temperature at which the resin is dispersed in water and the mobility of the resin molecular chain is high, the hydrophilic group can easily come into contact with water. Even a resin having only a functional group concentration can achieve water dispersibility. Such a relationship can be specifically shown by Expression (3). “LOG (MV)”, which is the logarithm of the melt viscosity of the resin at 80 ° C., is an index of the mobility of the resin. “AV” which is the acid value of the resin is an index of the hydrophilic group concentration of the resin. When the melt viscosity and acid value of the resin satisfy the formula (3), an aqueous dispersion can be easily formed by simply stirring the resin and the aqueous solution of the basic compound without using an emulsifier and an organic solvent. be able to.

  When the melt viscosity (unit: Pa · s) at 80 ° C. of the polylactic acid-based polyester resin of the present invention is MV, Log (MV) is 1 or more and 4 or less, preferably 1.7 or more and 3.9 or less, More preferably, it is 2 or more and 3.8 or less, More preferably, it is 2.2 or more and 3.6 or less. When Log (MV) is larger than 4, plasticization at the time of dispersion is insufficient, the effect of dispersing the hydrophilic group is not sufficiently exhibited, and the dispersion tends to be poor. On the other hand, if Log (MV) is smaller than 1, the cohesive force of the resin is decreased, and the strength of the coating film is decreased. For example, when used as an adhesive, there is a tendency that a defect such as poor adhesion occurs.

  The polylactic acid-based polyester resin aqueous dispersion of the present invention can be obtained by easily dispersing the polylactic acid-based polyester resin of the present invention with warm water in the presence of a basic compound. If the water temperature in the dispersion process is too high, the evaporation rate of water becomes high, and it becomes difficult to control the blending ratio. Moreover, when the water temperature in a dispersion | distribution process is too high, when a basic compound with high volatility is used, the volatilization rate of a basic compound will become high, and control of a compounding ratio will also become difficult. On the other hand, in order to promote dissolution, it is preferable to sufficiently soften the resin. From this point, it is preferable to make the water temperature as high as possible. From the above viewpoint, it is preferable that the temperature of the water to be dissolved is about 80 ° C. Therefore, in the present invention, melt viscosity at 80 ° C. is adopted as an index of plasticization when the polylactic acid-based polyester resin of the present invention is dispersed.

  The acid value of the polylactic acid-based polyester resin of the present invention is from 300 eq / ton to 2500 eq / ton, preferably from 400 eq / ton to 2300 eq / ton, more preferably from 500 eq / ton to 2100 eq / ton. If the resin acid value is too low, the resin cannot exhibit self-emulsifying properties, and the curability of a cured coating film using this resin tends to be low. On the other hand, water dispersibility tends to increase by increasing the resin acid value. However, if the acid value exceeds 2500 eq / ton, the water absorption of the resin increases and the resin is easily hydrolyzed even in a solid resin state. There is a tendency for stability to deteriorate. Moreover, the water resistance of the cured coating film using this resin also tends to deteriorate.

  The number average molecular weight of the polylactic acid-based polyester resin of the present invention is preferably from 2,000 to 50,000, more preferably from 3,000 to 45,000, still more preferably from 4,000 to 40,000. It is as follows. If the number average molecular weight is too low, the cohesive force of the resin tends to be small and the adhesiveness tends to be poor. On the other hand, if the number average molecular weight is too high, the cohesive strength of the resin increases, and the water dispersibility tends to be poor. For this reason, even if it is possible to prepare an aqueous dispersion with a high concentration by the method of once dissolving in a solvent and performing phase transition to an aqueous system, it is extremely low when an aqueous dispersion is prepared by mixing with only a base compound and water. Often only aqueous dispersions of concentration can be obtained. Further, when the aqueous dispersion is adjusted by mixing only with the base compound and water, the particle diameter tends to be coarse and tends to precipitate immediately after production.

  The polylactic acid-based polyester resin of the present invention preferably has a lactic acid content of 40% by weight or more, more preferably 50% by weight or more, and still more preferably 60% by weight or more. If it is less than 40% by weight, it is difficult to say that the degree of biomass is low and the environment has a large effect of reducing carbon dioxide emissions and has a low load on the environment.

  The resin skeleton that realizes the characteristics of the polylactic acid-based polyester resin of the present invention may be linear or branched, but is more preferably branched. The branched polymer is said to be less entangled in the molecular chain than the linear polymer in the melting state, and the melt viscosity at the same molecular weight tends to be lower than that of the linear polymer having the same composition.

  The method for introducing an acid value into the polylactic acid resin is not particularly limited, but a method of reacting an acid anhydride with a hydroxyl group at the end of the resin is simple and preferable. In the case of adopting such a method, it is advantageous to use a branched polylactic acid resin as a raw material polylactic acid resin because the number of terminal groups per molecule is high, so that the acid value can be increased. The acid value of the polylactic acid-based polyester resin of the present invention can be easily adjusted by changing the ratio of the polylactic acid-based resin and the acid anhydride as raw materials.

Although the chemical structure of the polylactic acid-type polyester resin of this invention is not specifically limited, For example, what takes the chemical structure represented by the following formula | equation (4) can be mentioned as a preferable example.
Z— (O— (CO—Y—O) _q —X) _r (4)
Where Z is a residue of a polyol having r hydroxyl groups, Y is —CH (CH ₃ ) —, or —CH (CH ₃ ) — and a mixture of a linear or branched alkylene group having 2 to 10 carbon atoms, X Is a residue of a polybasic acid having two or more carboxyl groups or hydrogen, and X, Y, and Z may be a single species or a mixture of a plurality of species. q and r are positive integers, the average value of q is 5 or more, and the average value of r is 3 or more and 15 or less.

  The polylactic acid-based polyester resin represented by the formula (4) is, for example, ring-opening addition polymerization of a cyclic compound having lactic acid such as lactide as a constituent, using a polyhydric alcohol having 3 or more hydroxyl groups as an initiator, Subsequently, it can manufacture by making a polybasic acid react with a terminal hydroxyl group and introduce | transducing a carboxyl group into at least one part of a molecule terminal. The polylactic acid-based polyester resin represented by the formula (4) is one or two selected from a cyclic compound having a hydroxycarboxylic acid other than lactic acid such as glycolic acid as a constituent component and a lactone such as ε-caprolactone. A mixture of two or more species and a cyclic compound having lactic acid such as lactide as a constituent component are subjected to ring-opening addition polymerization using a polyhydric alcohol having three or more hydroxyl groups as an initiator, and then a terminal hydroxyl group is reacted with a polybasic acid to form a molecule. It can also be produced by introducing an acid value at the end.

  Examples of polyols having r hydroxyl groups include polyhydric alcohols having 3 or more hydroxyl groups and derivatives thereof. Examples of the polyhydric alcohol having three hydroxyl groups include trimethylolpropane and glycerin. Examples of the polyhydric alcohol having 4 or more hydroxyl groups include pentaerythritol, diglycerin, polyglycerin, xylitol, sorbitol, glucose, fructose, mannose and the like. Of these, polyglycerol, xylitol, and sorbitol are preferable because they have a large number of hydroxyl groups.

  Preferable examples of the derivative of the polyhydric alcohol having 3 or more hydroxyl groups include those in which a part or all of the hydroxyl groups of the polyhydric alcohol are added with alkylene oxide, and ethylene oxide is particularly preferable as the alkylene oxide. . The reactivity of the secondary hydroxyl group as an initiator for ring-opening polymerization of lactide or the like is considerably inferior to the reactivity of the primary hydroxyl group. Therefore, when the polyhydric alcohol has both a secondary hydroxyl group and a primary hydroxyl group, 2 A primary hydroxyl group is unlikely to be the starting point for ring-opening addition polymerization. Therefore, when a polyhydric alcohol having both a secondary hydroxyl group and a primary hydroxyl group is used as an initiator for ring-opening addition polymerization such as lactide, the hydroxyl groups possessed by the polyhydric alcohol are all primary only or all secondary only. In comparison, the branched structure tends to be less likely to be formed. In the case where the polyhydric alcohol has both a secondary hydroxyl group and a primary hydroxyl group, if an alkylene oxide such as ethylene oxide is preliminarily subjected to an addition reaction, the secondary hydroxyl terminal is converted to the primary hydroxyl terminal, so that lactide or the like is used. This is an effective starting point for the ring-opening addition polymerization, and a branched structure is easily formed, which is preferable.

  Moreover, as a preferable example of the derivative of the polyhydric alcohol having 3 or more hydroxyl groups, there can be mentioned one in which a part of the hydroxyl groups of the polyhydric alcohol is esterified with a fatty acid. Polyglycerin stearates and oleates are examples of such compounds, but they are highly safe compounds that are also used as food additives. It is possible to make the polylactic acid-based resin have a highly branched structure, which is preferable.

  A polymer polyol having 3 or more hydroxyl groups is also a preferred example of a polyhydric alcohol derivative having 3 or more hydroxyl groups. Specific examples of the polymer polyol having 3 or more hydroxyl groups include polyester polyol, polycarbonate polyol, and polyurethane polyol. Of these, polyester polyols composed of aliphatic components are preferred in view of biodegradability.

In the polylactic acid-based polyester resin of the present invention, Y is a mixture of —CH (CH ₃ ) — or —CH (CH ₃ ) — and a linear or branched alkylene group having 2 to 10 carbon atoms. The — (CO—Y—O) _q — can be easily obtained by subjecting lactides or a mixture of lactides and lactones to ring-opening addition polymerization using a polyol as an initiator. As lactides, for example, lactide (a cyclic dimer of lactic acid), glycolide (a cyclic dimer of glycolic acid) and the like can be used. Examples of lactones that can be used include β-propionlactone, β-butyrolactone, pivalolactone, γ-butyrolactone, γ-valerolactone, δ-valerolactone, and ε-caprolactone. Moreover, these compounds do not necessarily need to be used alone, and a plurality of types can be copolymerized. Among them, it is preferable to use ε-caprolactone and lactide which are excellent in biodegradability and easy to polymerize.

In the polylactic acid-based polyester resin of the present invention, _q in the-(CO-YO) q- is a positive integer, and the average value of q is 5 or more, more preferably 7 or more, and still more preferably 10 or more. is there. When the average value of q is too low, the molecular weight of the polylactic acid-based polyester resin that is inevitably obtained becomes low, and the cohesive force of the resin tends to be small and the adhesiveness tends to be poor. On the other hand, the average value of q is preferably 50 or less. If the average value of q is too high, the number average molecular weight of the resin is increased, the cohesive force of the resin is increased, the melt viscosity is increased, and water dispersibility may be deteriorated.

In the polylactic acid-based polyester resin of the present invention, the average value of _r in the-(O- (CO-YO) _q- X) _r is 3 or more and 15 or less, more preferably 3.5 or more and 14 or less, and still more preferably. Is 4 or more and 13 or less. If the average value of r is too low, the number of end groups of the polymer is small and the acid value that can be introduced by acid addition is small. Therefore, when the molecular weight of the resin is high, the water dispersibility is inferior, and the water dispersibility can be secured. If the molecular weight of the resin is lowered, the strength of the resin becomes unusable. On the other hand, if the average value of r is 15 or more, a crosslinking reaction may occur during the addition of a terminal acid and gelation may occur.

In the polylactic acid-based polyester resin of the present invention, the-(CO-YO) _q- is mainly composed of one or both of a D-lactic acid residue and a 6-hydroxycaproic acid residue and an L-lactic acid residue. It is preferable that it is the random copolymer which becomes. Further, the content of the L-lactic acid residue _in- (CO-YO-) _q- is preferably 90% by weight or less, more preferably 85% by weight or less, and still more preferably 80% by weight or less. . If the L-lactic acid content is too high, crystallinity appears remarkably, and the water dispersibility tends to be poor. On the other hand, when the L-lactic acid content exceeds 90% by weight, when used as an adhesive, crystallization progresses with time and a significant decrease in adhesive strength may be observed.

In the polylactic acid-based polyester resin of the present invention, the — (CO—YO) _q — is typically a ring-opening addition polymerization of L-lactide with either one or both of D-lactide and ε-caprolactone. The main component may be a random copolymer obtained by the above process, and other components may be copolymerized. A random copolymer mainly composed of either or both of D-lactide and ε-caprolactone and L-lactide can be prepared, for example, using a polyol as an initiator in the presence or absence of a conventionally known ring-opening polymerization catalyst. , D-lactide, ε-caprolactone, or both of them and L-lactide can be obtained by heating and stirring.

  In the polylactic acid-based polyester resin of the present invention, the X is a polybasic acid residue containing two or more carboxyl groups or hydrogen. Examples of the polybasic acid include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, orthophthalic acid, and naphthalenedicarboxylic acid and their anhydrides, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, Aliphatic dicarboxylic acids such as dimer acids and acid anhydrides thereof, unsaturated dicarboxylic acids such as maleic acid, fumaric acid, and terpene-maleic acid adducts and acid anhydrides thereof, 1,4-cyclohexanedicarboxylic acid, tetrahydrophthalic acid, Trivalent or higher carboxylic acids such as hexahydroisophthalic acid, 1,2-cyclohexene dicarboxylic acid, and the like, and acid anhydrides thereof, trimellitic acid, methylcyclohexeric carboxylic acid, and the acid anhydrides thereof. Can be mentioned. Among these, trimellitic anhydride can be easily reacted by an addition reaction, and two carboxyl groups can be introduced per molecule, so that a large amount of acid value can be introduced, which is advantageous for water dispersion. This is preferable. Further, succinic anhydride, which is a biomass raw material, is preferable because it can easily react and maintain a high degree of biomass.

  Further, as the polybasic acid, pyromellitic anhydride (PMDA), oxydiphthalic dianhydride (ODPA), 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA), 3,3 ′ , 4,4′-diphenyltetracarboxylic dianhydride (BPDA), ethylene glycol bisanhydro trimellitate (TMEG), 3,3 ′, 4,4′-diphenylsulfone tetracarboxylic dianhydride (DSDA) 4,4 ′-(hexafluoroisopropylidene) diphthalic dianhydride (6FDA), 2,2′-bis [(dicarboxyphenoxy) phenyl] propane dianhydride (BSAA), glycerin tris anhydro trimellitate Acid dianhydrides such as can also be used. When these compounds are used, the molecular weight can be increased by the chain extension effect, which is preferable from the viewpoint of improving the resin strength. In particular, it is particularly preferable to use ethylene glycol bisanhydro trimellitate (TMEG), which allows an addition reaction at a relatively low temperature, has a low cohesive force, and has good water dispersibility.

  The polylactic acid-based polyester resin of the present invention is a mixture of one or two or more selected from a cyclic compound having a hydroxycarboxylic acid other than lactic acid such as glycolic acid as a constituent and a lactone such as ε-caprolactone, and lactide. A cyclic compound having lactic acid as a constituent component is subjected to ring-opening addition polymerization using a polyhydric alcohol having 3 or more hydroxyl groups and a derivative thereof, and a polymer polyol having 3 or more hydroxyl groups as an initiator, and then a polybasic acid is added to the terminal hydroxyl group. It can also be produced by reacting and introducing an acid value at the molecular end. More specifically, a polyol containing 3 or more hydroxyl groups, lactide, ε-caprone lactone, and catalyst are charged all at once, heated to 150 ° C. or higher, polymerized for 1 to 3 hours, and further polybasic acid anhydride is obtained. In addition, by reacting for 1 to 2 hours, the polylactic acid-based polyester resin of the present invention can be obtained. In order to prevent the polybasic acid anhydride from ring-opening due to the reaction with water contained in the polymerization system, it is preferable to use each raw material after reducing the water content by vacuum drying or the like in advance. In order to avoid the influence of moisture during the polymerization, the polymerization is preferably performed in a vacuum or in an inert gas atmosphere. The polymerization temperature is preferably 180 ° C. or less in consideration of the thermal stability of polylactic acid. In addition, when an acid anhydride is added to a hydroxyl group, the polymerization rate can be increased by using a conventionally known acid addition catalyst. Examples of catalysts that can be expected to have such effects include amines such as triethylamine and benzyldimethylamine; quaternary ammonium salts such as tetramethylammonium chloride and triethylbenzylammonium chloride; imidazoles such as 2-ethyl-4-imidazole Pyridines such as 4-dimethylaminopyridine; phosphines such as triphenylphosphine; phosphonium salts such as tetraphenylphosphonium bromide; sulfonium salts such as sodium p-toluenesulfonate; sulfonic acids such as p-toluenesulfonic acid; octyl Examples thereof include organic metal salts such as zinc acid. Among these, amines, pyridines, and phosphines are more preferable as a catalyst for the ring-opening polymerization reaction. Particularly, when 4-dimethylaminopyridine is used, the polymerization reaction rate can be increased.

  When polymerizing the polylactic acid-based polyester resin of the present invention, it is effective to add various antioxidants. When the polymerization temperature is high or when the polymerization time is long, the polylactic acid segment has low heat resistance and may be oxidized and colored. In addition, when a segment having low heat resistance such as polyether is copolymerized, it may be more susceptible to oxidative degradation. In such a case, addition of an antioxidant is particularly effective. Examples of the antioxidant include known phenolic antioxidants, phosphorus antioxidants, amine antioxidants, sulfur antioxidants, nitro compound antioxidants, inorganic compound antioxidants, and the like. . A phenolic antioxidant having a relatively high heat resistance is preferable, and 0.05 to 0.5% by weight of the resin is preferably added.

  Since the polylactic acid-based polyester resin of the present invention has good water dispersibility, it can be easily dispersed in warm water in the presence of a basic compound. The liquid temperature during the production of the aqueous dispersion is preferably 40 ° C. or higher and 95 ° C. or lower, more preferably 55 ° C. or higher and 90 ° C. or lower, and further preferably 70 ° C. or higher and 85 ° C. or lower. Even if the water temperature is low, the dispersion proceeds, but it takes time. The higher the water temperature, the faster the dispersion. However, if the water temperature is too high, the evaporation rate of water increases, making it difficult to control the mixing ratio, and when using a highly volatile basic compound, The volatilization rate of the organic compound becomes high, and it becomes difficult to control the blending ratio.

  Examples of the basic compound used in the method for producing the polylactic acid polyester resin aqueous dispersion of the present invention include ammonia, an organic amine compound, an inorganic basic compound, and the like.

  Specific examples of the organic amine compound include alkylamines such as triethylamine, isopropylamine, ethylamine, diethylamine and sec-butylamine, alkoxyamines such as 3-ethoxypropylamine, propylamine and 3-methoxypropylamine, N , N-diethylethanolamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, monoethanolamine, diethanolamine, triethanolamine and other alkanolamines, morpholine, N-methylmorpholine , Morpholines such as N-ethylmorpholine. Of these organic amine compounds, the use of highly hydrophilic alkanolamines, particularly triethanolamine, can improve water dispersibility.

  Specific examples of the inorganic basic compound include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide, alkali metal carbonates such as sodium bicarbonate and sodium carbonate, bicarbonates, And ammonium carbonate etc. can be used. When using a basic compound of a polyvalent metal, since it may cause a plurality of carboxyl groups contained in the polylactic acid-based polyester resin of the present invention and a water-insoluble salt to deteriorate the dispersibility. Is preferably limited to a small amount.

  The basic compound requires an amount capable of neutralizing at least a part of the carboxyl groups of the polylactic acid-based polyester resin of the present invention, specifically, with respect to the acid value of the polylactic acid-based polyester resin of the present invention. It is desirable to add 0.5 equivalent to 1.0 equivalent. In addition, after forming an aqueous dispersion using a basic compound having an acid value of less than 1.0 equivalent with respect to the acid value of the polylactic acid-based polyester resin of the present invention, the basic compound is additionally added to form a final base. It is good also considering the addition amount of an ionic compound as 0.5 equivalent-1.0 equivalent with respect to an acid value. At this time, the pH of the aqueous dispersion is preferably adjusted to 6.5 to 7.0 from the viewpoint of suppressing hydrolysis of the polylactic acid segment. If the addition ratio of the basic compound is too low, the water dispersibility tends to be low. If it is too high, the pH of the water dispersion becomes high and the polylactic acid polyester resin may be hydrolyzed.

  In order to produce the aqueous dispersion of the polylactic acid-based polyester resin of the present invention, it is not necessary to use an emulsifier or an organic solvent, but the use is not necessarily excluded. The use of various nonionic emulsifiers and anionic emulsifiers may make it possible to further stabilize the aqueous dispersion. In some cases, a more stable aqueous dispersion may be obtained by previously dissolving the polylactic acid-based polyester resin of the present invention in an appropriate organic solvent and then causing phase transition.

  The polylactic acid-based polyester resin aqueous dispersion of the present invention can be used as an adhesive. Under the present circumstances, if the hardening | curing agent which reacts with a carboxyl group is added, an adhesive agent with higher adhesive force can be obtained. As said hardening | curing agent, various hardening | curing agents, such as amino resins, such as a melamine type and a benzoguanamine type, a polyvalent isocyanate compound, a polyvalent oxazoline compound, a polyvalent epoxy compound, a phenol resin, can be used. In particular, polyvalent epoxy compounds and polyvalent oxazoline compounds are preferable because they have high reactivity with carboxyl groups, can be cured at low temperatures, and can provide high adhesive strength. Multivalent metal salts can also be used as curing agents.

  When using these hardening | curing agents, it is preferable that the content is 5-50 mass parts with respect to 100 mass parts of polylactic acid-type polyester resins of this invention. When the blending amount of the curing agent is less than 5 parts by mass, the curability tends to be insufficient, and when it exceeds 50 parts by mass, the coating film tends to be too hard.

  Examples of the epoxy compound suitable as the curing agent for the water-based adhesive of the present invention include novolac type epoxy resins, bisphenol type epoxy resins, trisphenol methane type epoxy resins, amino group-containing epoxy resins, and copolymer type epoxy resins. it can. Examples of novolak-type epoxy resins include those obtained by reacting epichlorohydrin and / or methyl epichlorohydrin with novolaks obtained by reacting phenols such as phenol, cresol, and alkylphenol with formaldehyde in the presence of an acidic catalyst. be able to. Examples of bisphenol type epoxy resins include those obtained by reacting bisphenols such as bisphenol A, bisphenol F, and bisphenol S with epichlorohydrin and / or methyl epichlorohydrin, and condensates of bisphenol A diglycidyl ether and the bisphenols. And those obtained by reacting epichlorohydrin and / or methyl epichlorohydrin. Examples of the trisphenol methane type epoxy resin include those obtained by reacting trisphenol methane, tris-resole methane and the like with epichlorohydrin and / or methyl epichlorohydrin. Examples of amino group-containing epoxy resins include glycidylamines such as tetraglycidyldiaminodiphenylmethane, triglycidylparaaminophenol, tetraglycidylbisaminomethylcyclohexanone, N, N, N ′, N′-tetraglycidyl-m-xylenediamine, and the like. Can be mentioned. Examples of the copolymer type epoxy resin include a copolymer of glycidyl methacrylate and styrene, a copolymer of glycidyl methacrylate and styrene and methyl methacrylate, or a copolymer of glycidyl methacrylate and cyclohexylmaleimide, and the like. .

  Since the polylactic acid-based polyester resin aqueous dispersion of the present invention has an emulsifying effect, an epoxy compound that is not soluble in water can also be used as a curing agent, but a water-soluble epoxy resin is preferred because it is easier to use. Examples of the water-soluble epoxy resin include polyethylene glycol, glycerin and derivatives thereof, and water-soluble compounds such as sorbitol in which a part of the hydroxyl group is a glycidyl group. Examples of commercially available water-soluble epoxy resins include SR-EGM, SR-8EG, SR-GLG, SR-SEP manufactured by Sakamoto Yakuhin Kogyo Co., Ltd., Denacol EX-614, EX-512 manufactured by Nagase Chemitex Co., Ltd. , EX-412 and the like.

  As an oxazoline compound suitable as a curing agent for the aqueous adhesive of the present invention, a commercially available oxazoline compound can be used. Can be used.

  As a carbodiimide compound suitable as a curing agent for the aqueous adhesive of the present invention, a commercially available carbodiimide compound can be used, and Nisshinbo Carbodilite V-02, V-04 and the like can be used.

  As a polyvalent metal salt suitable as a curing agent for the aqueous adhesive of the present invention, calcium salt, zinc salt, aluminum salt and the like can be used, and calcium chloride and zinc ammonium carbonate are particularly preferable.

  Examples of the phenol resin suitable as the curing agent for the aqueous adhesive of the present invention include a condensate of alkylated phenols and / or cresols with formaldehyde. Specifically, alkylated phenols alkylated with alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, p-tert-amylphenol, 4,4'-sec-butylidenephenol, p -tert-butylphenol, o-cresol, m-cresol, p-cresol, p-cyclohexylphenol, 4,4'-isopropylidenephenol, p-nonylphenol, p-octylphenol, 3-pentadecylphenol, phenol, phenyl Examples include condensates of o-cresol, p-phenylphenol, xylenol and the like with formaldehyde.

  Examples of amino resins suitable as curing agents for the aqueous adhesive of the present invention include formaldehyde adducts such as urea, melamine, and benzoguanamine, and alkyl ether compounds obtained by alkoxylating these compounds with alcohols having 1 to 6 carbon atoms. Can be mentioned. Specific examples include methoxylated methylol urea, methoxylated methylol-N, N-ethylene urea, methoxylated methylol dicyandiamide, methoxylated methylol melamine, methoxylated methylol benzoguanamine, butoxylated methylol melamine, butoxylated methylol benzoguanamine, and the like. Preferred are methoxylated methylol melamine, butoxylated methylol melamine and methylolated benzoguanamine, each of which can be used alone or in combination.

  The isocyanate compound suitable as the curing agent for the aqueous adhesive of the present invention may be either a low molecular compound or a high molecular compound. Examples of the low molecular weight compound include aliphatic isocyanate compounds such as tetramethylene diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate, aromatic isocyanate compounds such as toluene diisocyanate and diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and isophorone. Mention may be made of alicyclic isocyanates such as diisocyanates. Moreover, trimers of these isocyanate compounds can be exemplified. Examples of the polymer compound include a terminal isocyanate group-containing compound obtained by reacting a compound having a plurality of active hydrogens with an excess of the low-molecular polyisocyanate compound. Examples of the compound having a plurality of active hydrogens include polyhydric alcohols such as ethylene glycol, propylene glycol, trimethylolpropane, glycerin and sorbitol, polyhydric amines such as ethylenediamine, hydroxyl groups such as monoethanolamine, diethanolamine and triethanolamine And compounds having an amino group, polyester polyols, polyether polyols, polyamides, and other active hydrogen-containing polymers.

  The isocyanate compound may be a blocked isocyanate. Examples of the isocyanate blocking agent include phenols such as phenol, thiophenol, methylthiophenol, cresol, xylenol, resorcinol, nitrophenol, and chlorophenol, oximes such as acetoxime, methyl ethyl ketoxime, and cyclohexanone oxime, methanol, ethanol, propanol, Alcohols such as butanol, halogen-substituted alcohols such as ethylene chlorohydrin and 1,3-dichloro-2-propanol, tertiary alcohols such as t-butanol and t-pentanol, ε-caprolactam, δ-valero Examples include lactams such as lactam, γ-butyrolactam, β-propyllactam, and other aromatic amines, imides, acetylacetone, acetoacetate ester, ethyl malonate. Examples include active methylene compounds such as tellurium, mercaptans, imines, ureas, diaryl compounds and sodium bisulfite. The blocked isocyanate is obtained by subjecting the above isocyanate compound, isocyanate compound and isocyanate blocking agent to an addition reaction by a conventionally known appropriate method.

  A water-based ink can be obtained by blending a color material with the polylactic acid-based polyester resin aqueous dispersion of the present invention, and the water resistance of the ink can be improved by blending a curing agent having reactivity with a carboxyl group. Can be improved. As the color material, a known pigment or dye can be blended. Since the polylactic acid-based polyester resin of the present invention has a high acid value of the polyester resin, the dispersibility of various pigments is large, and a high-concentration aqueous ink can be produced. As the curing agent, those exemplified in the adhesive application can be used.

  The water dispersion, adhesive and ink of the present invention can be adjusted to a viscosity and viscosity suitable for workability by blending various thickeners. From the stability of the system due to the addition of a thickener, nonionic ones such as methylcellulose and polyalkylene glycol derivatives, and anionic ones such as polyacrylates and alginates are preferred.

  The aqueous dispersion, adhesive and ink of the present invention can further improve applicability by using various surface tension modifiers. Examples of the surface tension adjusting agent include acrylic, vinyl, silicone, and fluorine surface tension adjusting agents, and are not particularly limited. And vinyl surface tension modifiers are preferred. If the addition amount of the surface tension modifier is excessive, the adhesive strength tends to be impaired. Therefore, the addition amount should preferably be limited to 1% by weight or less, more preferably 0.5% by weight or less based on the resin. is there.

  The aqueous dispersion obtained by the present invention is known in the manufacture of an aqueous dispersion or a surface smoothing agent, an antifoaming agent, an antioxidant, a dispersing agent, a lubricant, etc. with respect to the produced aqueous dispersion. These additives may be blended.

  The water dispersion, adhesive and ink of the present invention can be further improved in light resistance and oxidation resistance by adding various ultraviolet absorbers, antioxidants and light stabilizers. Light resistance is greatly improved by introducing a compound having an ultraviolet absorption effect and a light stabilization effect into the polyester skeleton, but an ultraviolet absorber, an antioxidant, an emulsion of a light stabilizer, and an aqueous solution are dispersed in a polyester resin in water. Addition to the body also improves the weather resistance. As the ultraviolet absorber, various organic types such as benzotriazole, benzophenone, and triazine, and inorganic types such as zinc oxide can be used. As the antioxidant, various polymers generally used for polymers such as hindered phenols, phenothiazines and nickel compounds can be used. Various light stabilizers for polymers can be used, but hindered amines are effective.

  A layer (A layer) composed of the polylactic acid-based polyester resin of the present invention and a layer (B layer) selected from the group consisting of a film, a sheet, a woven fabric, a nonwoven fabric and paper can be laminated to form a laminate. The laminate can be easily obtained by, for example, applying the aqueous adhesive and / or aqueous ink of the present invention to a layer (B layer) selected from the group consisting of a film, a sheet, a woven fabric, a non-woven fabric, and paper and drying it. Can be obtained. The water-based adhesive and water-based ink of the present invention show strong adhesion to films, sheets, woven fabrics, non-woven fabrics and papers made of various raw materials, but polylactic acid, polyester, polyurethane, polyamide, cellulose, starch, vinyl chloride, chloride It exhibits particularly high adhesion to films and sheets made from vinylidene, chlorinated polyolefins and these chemically modified substances. Among these, when combined with a film, sheet and paper made of biomass raw materials such as polylactic acid, cellulose and starch, the biomass degree of the entire laminate can be made extremely high. Moreover, since the polylactic acid-based polyester resin water-based adhesive and water-based ink of the present invention exhibit high adhesive strength to various metal vapor-deposited films and metal oxide vapor-deposited films, the three layers of the A layer / metal vapor-deposited layer / B layer are used. It is also useful to use as a laminate having a structure or a laminate having a three-layer structure of the A layer / metal oxide vapor deposition layer / B layer. Although the metal and B layer used for a metal vapor deposition layer and a metal oxide are not specifically limited, Especially the adhesive force of the aluminum vapor deposition film and the polylactic acid-type polyester resin water-based adhesive and water-based ink of this invention is large. The polylactic acid-based polyester resin water-based adhesive and water-based ink of the present invention exhibit high adhesion to various metal deposited films and various metal oxides because of the high acid value of the polyester resin of the present invention. It appears to be. Since these laminates have a high degree of biomass, they are suitable for use as materials that are disposable in a relatively short period of time, such as packaging materials, and are particularly suitable as food packaging materials.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited by the following examples, but may be implemented with appropriate modifications within a scope that can meet the gist of the present invention. These are all included in the technical scope of the present invention.

  Hereinafter, unless otherwise specified, parts represent parts by weight. The measurement and evaluation methods employed in the present specification are as follows.

<Resin composition>
A resin sample was dissolved in deuterated chloroform or deuterated dimethyl sulfoxide, and ¹ H-NMR analysis and ¹³ C-NMR analysis were performed as necessary using an NMR apparatus 400-MR manufactured by VARIAN. The composition was determined and expressed in weight percent. The lactic acid content (% by weight) was calculated based on the resin composition on the left.
The L / D ratio of lactic acid was determined by the following method.
A 5 g / 100 mL chloroform solution of the sample was prepared, and the specific rotation was measured at a measurement temperature of 25 ° C. and a measurement light source wavelength of 589 nm to obtain [α] obs. Further, in the sample composition obtained by the above-described method, a resin having a composition in which all of the lactic acid component is substituted with the L-lactic acid component is polymerized, and the specific rotation is measured by the same method as [α] obs, and [α] 100 It was.
OP [%] = ABS ([α] obs / [α] 100) × 100
When OP = 100%, the lactic acid contained in the sample is all L-form, and when OP = 0%, the contents of L-form and D-form are equal 50% respectively, and L-lactic acid / (L-lactic acid + D Lactic acid) = 50 + [OP] / 2. From the left, the ratio of L-lactic acid to D-lactic acid was calculated.

<Number average molecular weight>
A resin sample was dissolved in tetrahydrofuran so that the resin concentration was about 0.5% by weight and filtered through a polytetrafluoroethylene membrane filter having a pore size of 0.5 μm, and tetrahydrofuran was used as the mobile phase. The molecular weight was measured by gel permeation chromatography (GPC) using a differential refractometer as a detector. The flow rate was 1 mL / min and the column temperature was 30 ° C. Showa Denko KF-802, 804L and 806L were used for the column. Monodisperse polystyrene was used as the molecular weight standard.

<Acid value>
Dissolve 0.8 g of resin sample in 20 ml of N, N-dimethylformamide and titrate phenolphthalein with 0.1N sodium methoxide in methanol in the presence of an indicator. The neutralization point was expressed in terms of equivalents (equivalents / 10 ⁶ g) per 10 ⁶ g of resin.

<Melt viscosity>
Using a flow tester (CFT-500C type) manufactured by Shimadzu Corporation, a resin sample dried to a moisture content of 0.1% or less is filled into a cylinder at the center of a heating body set at 80 ° C. A pressure (4.9 MPa) was applied to the sample through a jar, and the molten sample was extruded from a die (hole diameter: 0.5 mm, thickness: 20 mm) at the bottom of the cylinder, and the plunger descending distance and descent time were recorded. The melt viscosity was calculated.

<Storage stability>
After the resin sample was stored in the open atmosphere at 50 ° C. for 10 days, the number average molecular weight was measured to evaluate the change in molecular weight before and after storage.
(Judgment) ○: Change in number average molecular weight is less than 5%
Δ: Change in number average molecular weight is 5% or more and less than 10%
×: Change in number average molecular weight is 10% or more

<Evaluation of water dispersibility>
After adding a predetermined amount of resin, basic compound and water to a 500 ml glass flask equipped with a thermometer, stirrer and Liebig condenser, keep the temperature at 80 ° C. and stir at 400 rpm for 1 hour, then visually disperse in water Was judged.
(Judgment) ◯: There is no undispersed material and the resin is completely dispersed.
Δ: Undispersed material exists.
X: Resin is not dispersed at all.

<Average particle size of water dispersion>
The arithmetic average diameter based on the volume particle diameter of the water dispersion sample was measured using HORIBA LB-500 and adopted as the average particle diameter of the water dispersion. However, for those having water dispersibility Δ or ×, the average particle diameter was not measured, and “−” was displayed.

<Preparation of water-based adhesive>
To the aqueous dispersion, a water-soluble epoxy resin SR-SEP (manufactured by Sakamoto Pharmaceutical Co., Ltd.) was blended as a curing agent at the ratio shown in Table 3 to prepare an aqueous adhesive.

<Preparation of adhesive evaluation sample>
An aqueous adhesive was applied to a corona-treated surface of a 25 μm thick PET film (manufactured by Toyobo Co., Ltd.) so that the thickness after drying was 5 μm, and dried at 80 ° C. for 5 minutes. The corona-treated surface of another 25 μm thick PET film was bonded to the adhesive surface, pressed at 80 ° C. under a pressure of 3 kgf / cm ² for 30 seconds, cured by heat treatment at 40 ° C. for 8 hours, and peeled off. A sample for strength evaluation was obtained (for initial evaluation).
Moreover, after immersing the said sample in 25 degreeC water for 5 hours, the surface water was fully wiped off and it was set as the sample for water resistance evaluation.

<Evaluation of adhesiveness>
The peel strength was measured and evaluated for adhesion. At 25 ° C., a 180 ° peel test was performed at a tensile speed of 300 mm / min, and the peel strength was measured. Considering from practical performance, 2 N / cm or more is good. However, for water dispersibility of Δ or ×, an aqueous adhesive was prepared using the supernatant liquid part, and an adhesive evaluation sample was prepared. However, since there are few active ingredients, the thickness after drying becomes 5 μm. Although it was impossible to apply, a PET film was bonded to the coated surface by the above-mentioned method, and a peel strength evaluation sample was prepared and peel strength was measured. The peel strength was 0.1 / cm. Since it was as follows and it was judged that an accurate measurement was not possible, "-" was displayed.

<Evaluation of water resistance>
The adhesive evaluation sample was immersed in water at 25 ° C. for 5 hours, the surface water was sufficiently wiped off, and a 180 ° peel test was conducted at 25 ° C. and a tensile speed of 300 mm / min to measure peel strength. However, those having a water dispersibility of Δ or × showed almost no adhesion, so that the water resistance was not measured, and “−” was displayed.

Hereinafter, the abbreviations of the compounds shown in the text and tables in the examples indicate the following compounds, respectively.
P-GLY: polyglycerin # 750 (number average molecular weight 750)
P-GLY-EO750: Diglycerin ethylene oxide adduct (number average molecular weight 750)
P-GLY-MOS: Decaglycerin monooleate
PEG1000: Polyethylene glycol (number average molecular weight 1000)
L-LD: L-lactide D-LD: D-lactide CL: ε-caprolactone TMA: trimellitic anhydride SC: succinic anhydride MA: maleic anhydride TEA: triethylamine TETA: triethanolamine AN: aqueous ammonia (28% )
NaHCO3: Sodium bicarbonate

Example A-1
Polylactic acid polyester resin No. Production of 1 Into a 500 ml glass flask equipped with a thermometer, a stirrer, and a Liebig condenser, 7.7 parts of diglycerin ethylene oxide adduct (number average molecular weight 750), 74.4 parts of L-lactide, 15.2 ε-caprolactone 15.2 0.028 part of tin octylate was charged as a part and a catalyst, and nitrogen gas was circulated at 60 ° C. for 30 minutes. Subsequently, the pressure was reduced at 60 ° C. for 30 minutes to further dry the contents. The temperature of the polymerization system was raised to 180 ° C. while flowing nitrogen gas again, and the mixture was stirred for 3 hours after reaching 180 ° C. Next, 0.018 part of phosphoric acid was added, and after stirring for 20 minutes, the system was depressurized to distill off unreacted lactide and caprolactone. About 20 minutes later, after the distillation of unreacted material was stopped, 4.4 parts of succinic anhydride was added and stirred at 180 ° C. for 2 hours, and then the contents were taken out and cooled. Table 1 shows the composition, number average molecular weight, lactic acid content, and the like of the obtained polylactic acid-based polyol A.

Examples A-1 to A-8, Comparative Examples A-9 to A-15
Polylactic acid polyester resin No. Production of 2 to 15 Polylactic acid polyester resin No. 1 except that polylactic acid-based polyester resin No. 1 2 to 15 were synthesized, and polylactic acid polyester resin No. 1 was synthesized. Evaluation similar to 1 was performed. The evaluation results are shown in Tables 1 and 2.

  Polylactic acid polyester resin No. No. 9 has a low resin acid value and does not satisfy the formula (3), and is outside the scope of the present invention. Polylactic acid polyester resin No. 10 does not satisfy the formula (3) and is outside the scope of the present invention. Polylactic acid polyester resin No. No. 11 has a high resin acid value and is outside the scope of the present invention. Resin No. No. 9 is inferior in storage stability, but is presumed to have a high acid value and high water absorption. Polylactic acid polyester resin No. No. 12 has a small Log (MV) and is outside the scope of the present invention. Polylactic acid polyester resin No. No. 13 has a large Log (MV) and does not satisfy the formula (3), and is outside the scope of the present invention. Polylactic acid polyester resin No. 14 does not satisfy Expression (3) and is outside the scope of the present invention. Polylactic acid polyester resin No. 15 also does not satisfy the formula (3) and is outside the scope of the present invention.

Example C-1
Production and Evaluation of Polylactic Acid Polyester Resin Aqueous Dispersion and Aqueous Adhesive Polylactic acid polyester resin No. 1 was added to a 500 ml glass flask equipped with a thermometer, stirrer and Liebig condenser. 25 parts, 1.1 parts of TEA and 75 parts of water were charged, heated to 80 ° C. and stirred for 1 hour, and then the contents were taken out and cooled to produce a polylactic acid-based polyester resin aqueous dispersion 1. The particle size of the obtained water dispersion was measured. Furthermore, the hardening | curing agent was mix | blended with the above-mentioned method, and the adhesiveness and water resistance of the obtained coating film were evaluated. The results are shown in Table 3.

Examples C-2 to C-8
In the same manner as in Example 1, except that the charged raw materials and their ratios were changed to produce polylactic acid polyester resin water dispersions, and polylactic acid polyester resin water dispersions 2 to 7 were produced. Further, in the same manner as in Example 1, a curing agent was blended into the polylactic acid-based polyester resin aqueous dispersions 2 to 7, and the adhesion and water resistance of the obtained coating film were evaluated. The results are shown in Table 3. All showed high water dispersibility, and the cured coating film showed high adhesion and water resistance.

Comparative Examples C-9 to C-15
In the same manner as in Example 1, except that the raw materials and the ratios thereof were changed to try to produce a polylactic acid-based polyester resin aqueous dispersion, and the aqueous dispersion was further obtained in the same manner as in Example 1. A curing agent was blended, and the adhesion and water resistance of the obtained coating film were evaluated. The results are shown in Table 4.

  In Comparative Examples C-9 and C-10, a large amount of undispersed resin was present even after stirring for 1 hour, and a large amount of undispersed resin remained even after stirring for 1 hour. Polylactic acid-based polyester resin No. used in Comparative Example C-9 9, Resin No. 10 does not satisfy the formula (3) and is outside the scope of the present invention. In order to sufficiently plasticize the resin in the water dispersion step, it is presumed that the dispersion of the polylactic acid-based polyester resin hardly progressed because the acid value was too low compared to the melt viscosity.

  In Comparative Examples C-11 and C-12, the water dispersibility of the polylactic acid-based polyester resin was good, but Comparative Example C-11 had poor water resistance, and Comparative Example C-12 had poor adhesion. It was. Resin No. used in Comparative Example C-11 No. 11 has a high acid value of the resin and is outside the scope of the present invention. Although the curing agent equivalent to the acid value is blended, it is presumed that the water resistance is poor because many unreacted carboxyl groups remain. Resin No. used in Comparative Example C-12 No. 12 has a low melt viscosity of the resin and is outside the scope of the present invention. Since the melt viscosity is low, the cohesive force is low and the adhesiveness is estimated to be poor.

  Polylactic acid-based polyester resin No. used in Comparative Example C-13 In No. 13, the resin was hardly dispersed after stirring for 1 hour, and further stirring was continued for 1 hour. Resin No. No. 13 has a high melt viscosity of the resin, does not satisfy the formula (3), and is outside the scope of the present invention. In order to sufficiently plasticize the resin in the water dispersion step, it is presumed that the acid value was too low compared with the melt viscosity, so that the dispersion could hardly be performed.

  Resin No. used in Comparative Example C-14 14, Resin No. used in Comparative Example C-15. No. 15 showed little dispersion of the resin after stirring for 1 hour, and further continued stirring for 1 hour, but could hardly be dispersed. Resin No. 14, Resin No. 15 does not satisfy the formula (3) and is outside the scope of the present invention. In order to sufficiently plasticize the resin at the water dispersion temperature, it is presumed that almost no dispersion was possible because the acid value was too low compared to the melt viscosity.

  The polylactic acid-based polyester resin of the present invention can be easily dispersed in water only with a basic compound and water, and can provide an environmentally friendly resin and an aqueous dispersion. Moreover, a coating film with high water resistance can be provided by mix | blending a hardening | curing agent.

Claims (14)

A polylactic acid polyester resin characterized by satisfying the formulas (1), (2) and (3).
1 ≦ Log (MV) ≦ 4 (1)
300 ≦ (AV) ≦ 2,500 (2)
Log (MV) ≦ 0.0028 × (AV) +1.2 (3)
However, MV is the melt viscosity (Pa · s) of the polylactic acid-based polyester resin at 80 ° C., and AV is the acid value (eq / t) of the polylactic acid-based polyester resin.   The polylactic acid-based polyester resin according to claim 1, wherein the lactic acid content is 40% by weight or more.   The polylactic acid-based polyester resin according to claim 1 or 2, wherein the number average molecular weight is 2,000 or more and 50,000 or less.   The polylactic acid-type polyester resin water dispersion containing the polylactic acid-type polyester resin in any one of Claims 1-3, a basic compound, and water.   The polylactic acid-based polyester resin aqueous dispersion according to claim 4, which does not contain a surfactant.   The polylactic acid-based polyester resin aqueous dispersion according to claim 4 or 5, which does not contain an organic solvent.   A step of obtaining a polylactic acid-based polyester resin aqueous dispersion by mixing the polylactic acid-based polyester resin according to any one of claims 1 to 3, a basic compound, and water without adding a surfactant and an organic solvent. A method for producing an aqueous dispersion of a polylactic acid-based polyester resin.   An aqueous resin composition comprising the polylactic acid-based polyester resin according to any one of claims 1 to 3 and a curing agent having reactivity with a carboxyl group.   The aqueous resin composition according to claim 8, wherein the curing agent is one or more selected from the group consisting of a polyvalent epoxy compound, an oxazoline resin, a carbodiimide resin, and a polyvalent metal salt.   An aqueous adhesive comprising the aqueous resin composition according to claim 8 or 9.   A water-based ink comprising the water-based resin composition according to claim 8 or 9 and a color material.   A laminate comprising a layer (A layer) comprising the polylactic acid-based polyester resin according to any one of claims 1 to 3 and a layer (B layer) selected from the group consisting of a film, a sheet, a woven fabric, a nonwoven fabric and paper.   The laminate according to claim 12, wherein the B layer is mainly composed of a biomass-derived material and / or a chemically modified material of the biomass-derived material.   The packaging material which has the laminated body of Claim 12 or Claim 13 as a component.