JP6146416B2 - Polylactic acid-based polyester resin, polylactic acid-based polyester resin aqueous dispersion, and method for producing polylactic acid-based polyester resin aqueous dispersion - Google Patents

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 carried out to disperse itself. 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, a stable aqueous dispersion is obtained without using an emulsifier, and when used as a binder component, it exhibits high adhesion, but the process for producing an aqueous dispersion There is room for improvement in terms of reducing 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 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 mass 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 polyester resin aqueous dispersion comprising the polylactic acid 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 process for producing a polylactic acid-based polyester resin aqueous dispersion, 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 according to <8>, wherein the curing agent is one or more selected from the group consisting of a polyvalent epoxy compound, a polyvalent oxazoline compound, a carbodiimide compound, and a polyvalent metal salt. Composition.
<10> An aqueous adhesive comprising the aqueous resin composition according to <8> or <9>.
<11> An aqueous paint comprising the aqueous resin composition according to <8> or <9>.
<12> A water-based ink comprising the water-based resin composition according to <8> or <9> and a coloring material.
<13> 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 The laminated body characterized by including.
<14> The laminate according to <13>, wherein the B layer is mainly composed of a biomass-derived substance and / or a chemically modified substance of a biomass-derived substance.
<15> A packaging material comprising the laminate according to <13> or <14> as a constituent element.
<16> A sustained-release biodegradable coating agent comprising the aqueous resin composition according to <8> or <9>.
<17> A sustained-release biodegradable coated body, wherein the component to be coated is coated with the sustained-release biodegradable coating agent according to <16>.
<18> The controlled release according to <17>, wherein the component to be coated has one or more functions of insecticidal, herbicidal, sterilizing, antifungal, biological attraction and biological repelling. Biodegradable covering.
<19> The sustained-release biodegradable coating according to <17>, wherein the component to be coated has one or more functions of physiological activity, growth promotion, and nutritional supplementation for living organisms. body.

  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 of 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, when Log (MV) is smaller than 1, the cohesive force of the resin is reduced, and the strength of the coating film is reduced. For example, when used as an adhesive, there is a tendency that defects such as poor adhesion occur.

  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 300 eq / t (meaning ton) to 2,500 eq / t, preferably 400 eq / t to 2,300 eq / t, more preferably 500 eq / t. The above is 2,100 eq / t or less. If the resin acid value is too low, the resin cannot exhibit self-emulsifying properties, and the curability of the coating film using this resin tends to be low. On the other hand, the water dispersibility tends to increase by increasing the resin acid value. However, if the acid value exceeds 2,500 eq / t, the water absorbency of the resin increases and the resin is hydrolyzed even in a solid resin state. The storage stability tends to be poor. 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 2,000 or more and 50,000 or less, more preferably 3,000 or more and 45,000 or less, and further preferably 4,000 or more and 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. Therefore, even if it is possible to prepare a high-concentration aqueous dispersion by the method of once dissolving in a solvent and performing phase transition to an aqueous system, it is extremely difficult to prepare an aqueous dispersion by mixing only with a basic compound and water. Often only low concentration aqueous dispersions can be obtained. Further, when an aqueous dispersion is prepared by mixing only with a basic compound and water, the particle size tends to be coarse and tends to precipitate immediately after production.

  The polylactic acid polyester resin of the present invention preferably has a lactic acid content of 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more. If it is less than 40% by mass, it is difficult to say that the degree of biomass is low, the carbon dioxide emission reduction effect is large, and the material has a low environmental load.

  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 have smaller molecular chain entanglement than the linear polymer in the molten state, and the melt viscosity at the same molecular weight tends to be lower than that of the linear polymer having the same composition.

  A method for introducing an acid group into the polylactic acid-based polyester 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. When such a method is employed, it is advantageous to use a branched polylactic acid-based polyester resin as a raw material polylactic acid-based polyester 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 polyester resin to the raw material and the acid anhydride.

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)
Wherein Z is a residue of a polyol having r hydroxyl groups, Y is a group in which —CH (CH ₃ ) — or —CH (CH ₃ ) — and a linear or branched alkylene group having 2 to 10 carbon atoms are mixed. , 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 plural species. q and r are positive numbers, 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 group at the terminal.

  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 group in which —CH (CH ₃ ) — or —CH (CH ₃ ) — and a linear or branched alkylene group having 2 to 10 carbon atoms are mixed. 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 number, 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 terminal groups of the polymer is small and the acid value that can be introduced by acid addition is small. 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 exceeds 15, a cross-linking reaction may occur at the time of terminal acid addition 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. The content of the L-lactic acid residue _in- (CO-YO-) _q- is preferably 90% by mass or less, more preferably 85% by mass or less, and still more preferably 80% by mass 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 mass, when used as an adhesive, crystallization proceeds 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, List alicyclic dicarboxylic acids such as hexahydroisophthalic acid and 1,2-cyclohexene dicarboxylic acid and their anhydrides, trivalent or higher carboxylic acids such as trimellitic acid and methylcyclohexeric carboxylic acid and their anhydrides. Can do. Among these, trimellitic anhydride can be easily reacted by an addition reaction, and since two carboxyl groups can be introduced per molecule, a large amount of acid groups 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 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 group at the molecular end. More specifically, a polyol, lactide, ε-caprolactone, and catalyst containing 3 or more hydroxyl groups are charged all at once, heated to 150 ° C. or higher and polymerized for 1 to 3 hours, and further added with a polybasic acid anhydride. The polylactic acid-based polyester resin of the present invention can be obtained by reacting for 1 to 2 hours. In order to prevent the polybasic acid anhydride from 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 And 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 obtaining the polylactic acid-based polyester resin of the present invention by polymerization, 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 addition of 0.05% by mass to 0.5% by mass with respect to the resin is preferable.

  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-based polyester resin aqueous dispersion of the present invention include ammonia, an organic amine compound, and an inorganic basic compound.

  Specific examples of the organic amine compounds include alkylamines such as triethylamine, propylamine, isopropylamine, ethylamine, diethylamine and sec-butylamine, alkoxyamines such as 3-ethoxypropylamine 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, In addition, ammonium carbonate and the like 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 groups 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 of less than 1.0 equivalent with respect to the acid groups 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 group. 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 polyester resin aqueous dispersion of the present invention can be used as an aqueous 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 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, and a carbodiimide compound, 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 polyvalent epoxy compound suitable as the curing agent for the water-based adhesive of the present invention include novolak type epoxy resins, bisphenol type epoxy resins, trisphenol methane type epoxy resins, amino group-containing epoxy resins, and copolymer type epoxy resins. be able to. Examples of novolak-type epoxy resins include those obtained by reacting novolaks obtained by reacting phenols such as phenol, cresol, and alkylphenol with formaldehyde in the presence of an acidic catalyst and epichlorohydrin and / or methyl epichlorohydrin. 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. Can be obtained by reacting with epichlorohydrin and / or methyl epichlorohydrin. Examples of the trisphenol methane type epoxy resin include those obtained by reacting trisphenol methane, tris-resole methane, etc. 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 cyclohexyl maleimide, 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 Pharmaceutical Co., Ltd., and Denacol (registered trademark) EX-614 manufactured by Nagase Chemitex Co., Ltd. , EX-512, EX-412, and the like.

  As a polyvalent oxazoline compound suitable as a curing agent for the aqueous adhesive of the present invention, a commercially available oxazoline compound can be used, and Nippon Shokubai Epocross (registered trademark) WS-500, WS-700, Epocross (registered trademark). ) K-2010E, Epocross (registered trademark) K-2020E, etc. 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 (registered trademark) 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 and 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-o -Condensates of 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-ethyleneurea, 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 methoxylated methylolated benzoguanamine, which can be used alone or in combination.

  The polyvalent 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 low molecular weight compounds 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, methylethyl 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 activities such as aromatic amines, imides, acetylacetone, acetoacetate, and malonic acid ethylester. And methylene compounds, mercaptans, imines, ureas, diaryl compounds, sodium bisulfite and the like. The blocked isocyanate can be obtained by subjecting the above isocyanate compound and an 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.

  A water-based paint can be obtained by blending the polylactic acid-based polyester resin aqueous dispersion of the present invention with additives generally used for various pigments and paints, and further having a reactivity with respect to carboxyl groups. The water resistance of a coating film can be improved by mix | blending an agent. Examples of pigments include known organic / inorganic color pigments, extender pigments such as calcium carbonate and talc, rust preventive pigments such as red lead and lead oxide, aluminum powder, and various functional pigments such as zinc sulfide (fluorescent pigment). Can be blended. Additives include plasticizers, dispersants, anti-settling agents, emulsifiers, thickeners, antifoaming agents, antifungal agents, antiseptics, anti-skinning agents, anti-sagging agents, delustering agents, antistatic agents, A conductive agent, a flame retardant, etc. 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 paint can be produced. As the curing agent, those exemplified in the adhesive application can be used.

  The water dispersion, adhesive, ink and paint 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, ink and paint 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. Acrylic 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 mass or less, more preferably 0.5% by mass 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, ink and paint 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 emulsion or an aqueous solution of an ultraviolet absorber, an antioxidant, and a light stabilizer is dispersed in an aqueous polyester resin dispersion. Light resistance is also improved by adding to the above. 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 exhibit strong adhesion to films, sheets, woven fabrics, nonwoven fabrics and papers made of various raw materials, but polylactic acid, polyester, polyurethane, polyamide, cellulose, starch, polyvinyl chloride, It exhibits particularly high adhesion to films and sheets made from polyvinylidene chloride, 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. In addition, since the water-based adhesive and water-based ink obtained from the polylactic acid-based polyester resin of the present invention show high adhesive force to various metal vapor-deposited films and metal oxide vapor-deposited films, the layer A / metal vapor-deposited layer / B layer It is also useful to use a laminate having a three-layer structure as described above or a laminate having a three-layer structure of 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 an aluminum vapor deposition film, and the water-based adhesive and water-based ink of this invention is large. The water-based adhesive and water-based ink of the present invention exhibit high adhesion to various metal vapor-deposited films and various metal oxides because of the effect of the high acid value of the polylactic acid-based polyester resin of the present invention. Seem. 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.

  The polylactic acid-based polyester resin of the present invention and its aqueous dispersion can be used as a sustained-release biodegradable coating agent. Since the polylactic acid-based polyester resin of the present invention has an appropriate biodegradation rate, when it is left in the natural environment, it gradually biodegrades over a long period of time, and gradually releases the components to be coated into the environment. be able to. Therefore, a coated body formed by coating a coating agent such as a fertilizer, agricultural chemical, antifungal agent, bactericidal agent, or biological repellent with the biodegradable coating agent of the present invention is excellent in sustained release of the coating agent. Moreover, the biodegradable coating agent of this invention can form the water dispersion excellent in film forming property in the preferable embodiment, and can be used with the form of a coating film.

<Slow release biodegradable coating>
The sustained-release biodegradable coating in the present invention is obtained by coating the component to be coated with the sustained-release biodegradable coating in the present invention. The sustained-release biodegradable coating of the present invention may contain components other than the component to be coated and the sustained-release biodegradable coating of the present invention, such as other biodegradable resins, non-degradable resins, and the like. Biodegradable resins, hydrolysis accelerators, hydrolysis inhibitors and the like may be blended. The sustained-release biodegradable coating refers to those in which the component to be coated is coated with a sustained-release biodegradable coating, but only the same component as the component to be coated is present inside the coating. Not only those that also adhere to the outer surface.

  The sustained-release biodegradable coating in the present invention is gradually decomposed by organisms such as microorganisms in the natural environment such as the surface and the inside of soil, river lakes, and the ocean, and the components to be coated are treated for a long time in the process. It exhibits the effect of continuously releasing over a long period. For this reason, it can be used as a sustained-release agrochemical, slow-acting fertilizer, long-lasting antifouling paint, etc. by selecting an appropriate component to be coated.

<Coated components>
The component to be coated in the present invention is not particularly limited as long as it is a component that is desired to be gradually released in the natural environment. Specific examples of the component to be coated in the present invention include a component that can be expected to have a biological control action such as insecticidal, herbicidal, sterilizing, antifungal, biological attraction and biological repellent, and a growth promoting action on living organisms such as bioactive substances and fertilizer And / or a component that can be expected to have a nutritional supplement. Moreover, the component to be coated is not limited to a single component, and may be composed of a plurality of components.

<Method for producing sustained-release biodegradable coating>
Although the manufacturing method of the sustained release biodegradable coating body of this invention is not specifically limited, It is preferable to manufacture via the aqueous dispersion of the polylactic acid-type polyester resin of this invention. The component to be coated is dissolved or dispersed in an aqueous dispersion, and then the aqueous dispersion itself is sprayed to evaporate the water to form particles, or sprayed in the presence of some carrier to adhere to the carrier surface and / or the inside of the carrier. This is because a biodegradable coating can be easily obtained by applying to some adherend and forming a coating film, which is convenient. Moreover, if the biodegradable polylactic acid-based polyester resin is self-emulsifying, which can form an aqueous dispersion without the addition of a surfactant, the surfactant is released into the environment during the biodegradation process. This is preferable because the environmental load is reduced. Further, if the aqueous dispersion does not contain an organic solvent or uses a small amount of the organic solvent, the organic solvent is not released into the environment in both the manufacturing process of the covering and the use of the covering. Or, since it is less, the environmental load is further reduced, which is preferable.

  This application claims the benefit of priority based on Japanese Patent Application No. 2012-176999 filed on Aug. 9, 2012. The entire contents of the above Japanese Patent Application No. 2012-176999 are incorporated herein by reference.

  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, “part” represents “part by mass”. 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 mass%. The lactic acid content (% by mass) was calculated based on the resin composition shown 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 is dissolved in tetrahydrofuran so that the resin concentration is about 0.5% by mass and filtered through a polytetrafluoroethylene membrane filter having a pore size of 0.5 μm, and tetrahydrofuran is used as a 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 with 0.1N sodium methoxide in methanol in the presence of phenolphthalein indicator. The neutralization point was expressed in terms of equivalents (equivalents / 10 ⁶ g) per 10 ⁶ g of resin.

<Melt viscosity>
In a flow tester (CFT-500C type) manufactured by Shimadzu Corporation, a dried resin sample was filled in a cylinder at the center of a heated body set at 80 ° C. to a moisture content of 0.1% or less. A pressure (4.9 MPa) is applied to the sample through the plunger, the molten sample is extruded from the die (hole diameter: 0.5 mm, thickness: 20 mm) at the bottom of the cylinder, and the distance and time of descent of the plunger are 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. Dispersibility was determined.
(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 a ratio shown in Table 3 to prepare an aqueous adhesive.

<Preparation of adhesive evaluation sample>
A water-based 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. It was impossible to apply so. When a peel strength evaluation sample was prepared by laminating a PET film on the coated surface by the above-mentioned method and the peel strength measurement was performed, the peel strength was 0.1 N / cm or less, and it was determined that accurate measurement could not be performed. , “−” Is displayed.

<Evaluation of water resistance>
The sample for evaluation of adhesiveness was immersed in water at 25 ° C. for 5 hours, and then water on the surface was sufficiently wiped off, and a peel strength was measured by performing a 180 ° peel test at 25 ° C. and a tensile speed of 300 mm / min. 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% )
NaHCO ₃ : Sodium bicarbonate

Example A-1
Polylactic acid polyester resin No. Production of 1 7.7 parts of diglycerin ethylene oxide adduct (number average molecular weight 750), 74.4 parts of L-lactide, ε-caprolactone 15 in a 500 ml glass flask equipped with a thermometer, stirrer and Liebig condenser .2 parts and 0.028 part of tin octylate as a catalyst were charged 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 polyester resin.

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. FIG. 1 is a graph plotting the relationship between AV and Log (MV) of the polylactic acid-based polyester resin used in Examples and Comparative Examples.

  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. 11 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 placed in 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 C-1, except that the charged raw materials and the ratios thereof were changed, polylactic acid polyester resin aqueous dispersions were produced, and polylactic acid polyester resin aqueous dispersions 2 to 8 were produced. Furthermore, like Example C-1, the hardening | curing agent was mix | blended with the polylactic acid-type polyester resin aqueous dispersions 2-8, and the adhesiveness 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 C-1, except that the raw materials and the ratios thereof were changed and production of a polylactic acid-based polyester resin aqueous dispersion was attempted. A curing agent was blended in the same manner as in Example 1, 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. 1 used in Comparative Example C-9 and Comparative Example C-10. 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.

<Paint>
Production Example of Water-Based Paint (D-1) Polylactic acid-based polyester resin No. 1 was added to a 500 ml glass flask equipped with a thermometer, a stirrer and a Liebig condenser. 100 parts of TEA, 4.4 parts of TEA and 233 parts of water were added, heated to 70 ° C. and stirred for 1 hour, then the contents were taken out and cooled, and the filtrate was filtered through a 100 mesh filter cloth. 20 parts of Chemical Co., Ltd. M-40W), 150 parts of ion-exchanged water, 50 parts of titanium oxide (CR-93 produced by Ishihara Sangyo Co., Ltd.), 2.5 parts of 10% benzyl alcohol solution of sodium dodecylbenzenesulfonate Was added and dispersed uniformly by shaking for 3 hours using a glass bead type high speed shaker to obtain an aqueous paint (D-1).

Production Example of Water-Based Paint (D-2) In the water-based paint (D-1), polylactic acid polyester resin No. 1 instead of polylactic acid-based polyester resin No. 1 7 was used, and a water-based paint (D-2) was obtained by the same formulation and production as the water-based paint (D-1) except that the TEA amount was 6.8 parts.
A coating film performance test was performed using the water-based paints (D-1) and (D-2). In addition, preparation and evaluation of the coated plate followed the following method. The results are shown in Table 5.

Preparation of coated plate After applying the water-based paints (D-1) and (D-2) to a hot-dip galvanized steel plate, the coating was dried at 80 ° C. for 10 minutes and then baked at 140 ° C. for 30 minutes. The film thickness was 5 μm.

Evaluation method 1. Gloss The reflection at 60 degrees was measured using GLOSS METER (manufactured by Tokyo Denka Co., Ltd.).
◎: 90 or more ○: 80 or more and less than 90 Δ: 50 or more and less than 80 ×: less than 50

2. Boiling water test The appearance (blister generation state) of the coating film after the coated steel sheet was immersed in boiling water for 2 hours was evaluated. ◎: No blister ○: Blister generation area less than 10% Δ: Blister generation area 10-50%
×: Blister generation area over 50%

3. Solvent resistance In a room at 20 ° C., a load of 1 kgf / cm ² was applied to the coated surface with gauze soaked with methyl ethyl ketone, and the coating was reciprocated between 5 cm lengths. The number of round trips until the substrate was visible was recorded. If the substrate was not visible after 50 reciprocations,> 50 was displayed. The greater the number of times, the better the curability of the coating film.

4). Adhesion
In accordance with JIS K-5400 grid-tape method, draw 11 straight vertical and horizontal lines at 1mm intervals to reach the substrate with a cutter knife on the coating surface of the test plate. 100 squares were created. A cellophane pressure-sensitive adhesive tape was adhered to the surface, and the degree of cell peeling when the tape was rapidly peeled was observed and evaluated according to the following criteria.
(Double-circle): Coating film peeling is not seen at all.
○: Although the coating film was slightly peeled, 90 or more squares remained.
(Triangle | delta): A coating film peels and the remaining number of squares is 50 or more and less than 90 pieces.
X: The coating film was peeled off, and the number of cells remaining was less than 50.

<Ink>
Production Example of Water-based Ink (E-1) Polylactic acid-based polyester resin No. 1 was placed in a glass flask having a volume of 2,000 ml equipped with a thermometer, a stirrer, and a Liebig condenser. 100 parts of TEA, 4.4 parts of TEA and 233 parts of water were added, heated to 70 ° C., stirred for 1 hour, cooled to 30 ° C., and then an iron oxide yellow aqueous dispersion (manufactured by Dainichi Seika Kogyo Co., Ltd.) 19.6 parts of MF-5050 Yellow), 690.2 parts of water and 55 parts of 2-propanol were added, and the mixture was further stirred for 1 hour. The contents were taken out and filtered through a 100-mesh filter cloth. )

Production Example of Water-based Ink (E-2) In water-based ink (E-1), polylactic acid polyester resin No. 1 instead of polylactic acid-based polyester resin No. 1 A water-based ink was obtained in the same manner as in the water-based ink (E-1) except that 7 was used and the amount of TEA was 6.8 parts.
An ink coating film performance test was performed using the water-based inks (E-1) and (E-2). In addition, preparation and evaluation of the evaluation sample followed the following method. The results are shown in Table 6.

<Evaluation of dispersion stability of water-based ink>
The aqueous inks (E-1) and (E-2) were stored at 20 ° C. and −5 ° C. for 2 weeks, respectively, and the appearance change of the ink was evaluated.
◎: No change in appearance at all ○: Little change in appearance (occurrence of precipitate that can be redispersed by stirring)
Δ: Slightly sedimented (slightly remaining that cannot be redispersed by stirring)
×: Sediment generation

<Preparation of water resistance evaluation sample>
Water-based inks (E-1) and (E-2) were 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 2 μm. It dried for 30 minutes and was set as the sample for water resistance evaluation.

<Evaluation of water resistance>
The sample for water resistance evaluation was immersed in 25 ° C. water for 5 hours, and then water on the surface was sufficiently wiped off to confirm a change in appearance.
◎: No change in appearance ○: No change in appearance (A trace of water intrusion is observed in a very small part of the interface between the coating film and the substrate)
(Triangle | delta): The swelling by water is seen in a part of coating film.
X: Whole surface peeling / dissolution occurred.

<Laminated body>
Production Example of Laminate (F-1) A polylactic acid-based polyester resin No. 1 was added to a 500 ml glass flask equipped with a thermometer, a stirrer, and a Liebig condenser. 1 was charged with 100 parts, 4.4 parts of TEA and 233 parts of water, heated to 70 ° C. and stirred for 1 hour, then cooled to 30 ° C. or less, colloidal silica (Snowtex (registered trademark) manufactured by Nissan Chemical Industries, Ltd.) ) 100 parts of C) was added, and the mixture was further stirred for 1 hour, and the filtrate filtered through a 100 mesh filter cloth was added to a 25 μm thick PLA film (Innovia).
The film was applied to a corona-treated surface (Films) so that the thickness after drying was 5 μm, and dried at 80 ° C. for 30 minutes to obtain a laminate (F-1).

Production Example of Laminate (F-2) In the laminate (F-1), polylactic acid polyester resin No. 1 instead of polylactic acid-based polyester resin No. 1 7 was used, and a laminate (F-2) was obtained by the same composition and production as the laminate (F-1) except that the TEA amount was 6.8 parts.
A performance test was performed using the laminates (F-1) and (F-2). Evaluation followed the following method. The results are shown in Table 7.

<Biomass degree>
The mass% of the biomass-derived component contained in the total mass of the laminate was calculated.

<Biodegradability test>
Laminate 10cm x 10cm is put in a conposter (garbage disposal machine, Mitsui Home Co., Ltd. (MAM)). After 7 days, the sample form is visually observed, and the degree of biodegradability is 4 levels according to the following criteria. It was evaluated with.
◎: The sample form is completely absent ○: The sample form is almost absent △: There is a sample fragment ×: The sample form remains almost

<Slow release biodegradable coating agent>
A polylactic acid-based polyester resin No. 1 was added to a 500 ml glass flask equipped with a thermometer, a stirrer, and a Liebig condenser. 7 and 100 parts of TEA, 6.8 parts of TEA, and 233 parts of water were added, heated to 70 ° C. and stirred for 1 hour, then cooled to 30 ° C. or less, and colloidal silica (Snowtex C manufactured by Nissan Chemical Industries, Ltd.) After adding 100 parts and further stirring for 1 hour, the mixture was filtered through a 100 mesh filter cloth. The filtrate is spray-coated on a nitrogen-based granular fertilizer component having an average particle diameter of 4 mm using a jet coating apparatus, and moisture is evaporated and dried with hot hot air to obtain a coated granular sustained-release biodegradable coating G1. It was.
The filtrate was applied to a polypropylene sheet, dried in a hot air drier at 60 ° C., and then peeled off from the polypropylene sheet to prepare a sheet made of polylactic acid-based polyester resin H1 having a dry thickness of about 20 μm. Using this sheet, biodegradability in an aerobic dark place was evaluated. The specific evaluation method was based on ASTM-D5338. The evaluation results are shown in Table 8. The decomposition rate of this sheet was faster than that of a sheet made of polylactic acid-based polyester resin H2 described later, but was found to be slower than that of cellulose. The polylactic acid-based polyester resin H1 is suitable for a coating material and a coated body that exhibit a sustained release property and when it is desired to finish the release of the component to be coated in a relatively short period of time.

<Slow release biodegradable coating agent>
A polylactic acid-based polyester resin No. 1 was added to a 500 ml glass flask equipped with a thermometer, a stirrer, and a Liebig condenser. 6 was charged with 100 parts, TEA 11.3 parts, and water 233 parts. After heating to 70 ° C. and stirring for 1 hour, the mixture was cooled to 30 ° C. or lower to obtain colloidal silica (Snowtex C manufactured by Nissan Chemical Industries, Ltd.). After adding 100 parts and further stirring for 1 hour, the mixture was filtered through a 100 mesh filter cloth. The filtrate is spray-coated on a nitrogen-based granular fertilizer component having an average particle diameter of 4 mm using a jet coating apparatus, and moisture is evaporated and dried with hot hot air to obtain a coated granular sustained-release biodegradable coating G2. It was.
The filtrate was applied to a polypropylene sheet, dried in a hot air drier at 60 ° C., and then peeled from the polypropylene sheet to prepare a sheet made of polylactic acid-based polyester resin H2 having a dry thickness of about 20 μm. Using this sheet, biodegradability in an aerobic dark place was evaluated. The specific evaluation method was based on ASTM-D5338. The evaluation results are shown in Table 8. The degradation rate of this sheet is relatively slow and is suitable for coatings and coatings where release of the coated component over a relatively long period is required.

  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 (19)

Equation (1), (2), meet the (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. ]
A polylactic acid-based polyester resin characterized by having a chemical structure represented by the formula (4).
Z— (O— (CO—Y—O) _q —X) _r (4)
[However, Z is a residue of a polyol having r hydroxyl groups, Y is —CH (CH ₃ ) —, or —CH (CH ₃ ) — and a linear or branched alkylene group having 2 to 10 carbon atoms. The group 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 multiple species. q and r are positive numbers, 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 according to claim 1, wherein the lactic acid content is 40% by mass 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.   A polylactic acid polyester resin aqueous dispersion comprising the polylactic acid polyester resin according to any one of claims 1 to 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, comprising:   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, a polyvalent oxazoline compound, a carbodiimide compound, and a polyvalent metal salt.   An aqueous adhesive comprising the aqueous resin composition according to claim 8 or 9.   A water-based paint comprising the water-based 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 coloring material.   It contains the layer (A layer) which consists of a polylactic acid-type polyester resin in any one of Claims 1-3, and the layer (B layer) chosen from the group which consists of a film, a sheet | seat, a woven fabric, a nonwoven fabric, and paper. Laminated body.   The layered product according to claim 13, wherein said B layer consists of a biomass origin material and / or a chemical modification material of a biomass origin material.   A packaging material comprising the laminate according to claim 13 as a constituent element.   A sustained-release biodegradable coating agent comprising the aqueous resin composition according to claim 8 or 9.   A sustained-release biodegradable coating body, wherein the component to be coated is coated with the biodegradable coating agent according to claim 16.   The sustained-release biodegradation according to claim 17, wherein the component to be coated has one or more functions of insecticidal, herbicidal, sterilizing, antifungal, biological attraction and biological repellent. Covering.   18. The sustained-release biodegradable coating according to claim 17, wherein the component to be coated has one or more functions of biological activity, growth promotion and nutritional supplementation with respect to a living organism.

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