JPH08300570A - Lactic acid based polyester laminate paper - Google Patents

Abstract

PURPOSE: To manufacture a laminate paper suitable for the regeneration of waste paper by the constitution of lactic acid based polyester, having the specified range of weight average molecular weight containing the structural unit formed by the dehydration condensation of lactic acid and polyester structural unit formed by the dehydration condensation of dicarboxylic acid and diol, and a specific range of the melting point measured by DSC, and paper. CONSTITUTION: As lactic polyester to be used is of superior resistance and shaping properties, the weight average molecular weight of 20,000-400,000 is preferable, and the melting point measured by DSC is in the range of 70-20 deg.C. As for a polymerizing agent, preferably polyvalent carboxylic acid, an epoxy compound, isocyanate or the like is used alone or as a mixture. The adding amount of the polymerizing agent is preferably in the range of 0.001-5 pts.wt. to the total amount of the structural unit formed by the dehydration condensation of lactic acid and the polyester structural unit formed by dicarboxylic acid and diol. As for the use of a laminate paper, it is suitable for packaging food, as it is provided with superior flexibility, resistance to oils and stability. The laminate paper is also provided with hydrolyzing properties and biodegradability, and decomposed by hydrolysis, microbes and the like when it is thrown away into earth or sea water after use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lactic acid-based polyester laminated paper comprising a biodegradable lactic acid-based polyester layer and paper. More specifically, flexibility, oil resistance,
The present invention relates to a laminated paper which is excellent in biodegradability, and is excellent in hydrolyzability and biodegradability, so that paper can be easily recovered and decomposed in nature.

[0002]

2. Description of the Related Art In recent years, recycled paper is recycled from the viewpoint of environmental protection and forest resources, and after separating laminated paper laminated with synthetic resin into synthetic resin film and paper, recycled paper as pulp is recycled. Is actively carried out. Laminated paper used as packaging material for shopping bags, milk cartons, paper trays, paper cups, magazines, picture books, film boxes, etc. is made of synthetic resin such as polyethylene, polypropylene, polyester, polyvinyl chloride, melt-extruded or coated with solution. Things are widely used.

However, the laminated paper laminated with the synthetic resin has problems that it is extremely difficult to disintegrate the synthetic resin from the pulp when the waste paper is repulped, and a large amount of foreign matter is generated. ing. On the other hand, lactic acid-based polyester is highly safe, biodegradable, and the raw material lactic acid is economically advantageous because it is produced by fermentation from cheap molasses, corn starch, cheese whey, etc. A lot of research is being done to utilize it as a polymer that has low calories and is also environmentally friendly.

Regarding the laminated paper made of the lactic acid-based polyester, it has already been disclosed in JP-A-4-33448 and JP-A-4-33448.
336246 and JP-A-6-255039 are disclosed. They are related to laminated paper of polylactic acid, or a copolymer of lactic acid and ε-caprolactone and the like, but with regard to laminated paper of polylactic acid, it has poor flexibility and brittle properties, and also lactic acid and ε- Since the copolymer with caprolactone has poor heat resistance, it is difficult to obtain a stable molded product during the molding process, and there is a problem that it can be used only for a limited purpose.

[0005]

The problem to be solved by the present invention is that the laminate has sufficient flexibility and oil resistance, and also has hydrolyzability and excellent biodegradability, and is suitable for recycling waste paper. To provide paper.

[0006]

Means for Solving the Problems As a result of intensive investigations by the present inventors in order to solve the problems, as a result, a weight average of structural units obtained by dehydration condensation of lactic acid and polyester structural units obtained by dehydration condensation of dicarboxylic acid and diol is obtained. Molecular weight is 20,000 to 40
By laminating lactic acid-based polyester, which has a melting point of 70 to 200 ° C in DSC, on paper, it has excellent biodegradability and is excellent in hydrolyzability, flexibility and oil resistance. The inventors have found that a lactic acid-based polyester laminated paper is obtained and have completed the present invention.

[0007]

[Structure] That is, the present invention comprises a structural unit obtained by dehydration condensation of lactic acid and a polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol, and has a weight average molecular weight of 20,000 to 400,000.
It is a lactic acid-based polyester laminated paper composed of paper and a lactic acid-based polyester having a melting point of 70 to 200 ° C. in DSC.

More specifically, the lactic acid-based polyester has a weight ratio of the structural unit obtained by dehydration condensation of lactic acid and the polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol of 99 /.
1 to 50/50, wherein the lactic acid-based polyester further comprises a structural unit obtained by dehydration condensation of lactic acid, a polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol, and a high molecular weight agent. A lactic acid-based polyester laminated paper comprising the structural unit of

More specifically, the present invention relates to a lactic acid-based polyester laminated paper characterized in that the dicarboxylic acid and diol of the lactic acid-based polyester are particularly aliphatic dicarboxylic acid and aliphatic diol, and the lactic acid-based polyester. The lactic acid-based polyester laminate paper in which the dicarboxylic acid and diol is a dicarboxylic acid having a branched chain and diol, and particularly the lactic acid-based polyester laminate paper in which the diol of the lactic acid-based polyester is polyalkylene glycol.

The lactic acid-based polyester used in the present invention will be described below in order. The lactide referred to in the present invention is a cyclic compound in which two molecules of lactic acid are dehydrated and condensed, and the two lactic acid units constituting this are L-lactide in the case of only the L-form, D-lactide, D in the case of only the D-form. It is called meso-lactide when it is composed of body and L-form, and is called DL-lactide when it is composed of L-lactide and D-lactide equivalent.

In the present invention, in order to exhibit particularly high heat resistance and oil resistance, the lactide preferably contains L-lactide in an amount of 75% or more of the total lactide. It is preferable that the lactide contains 90% or more of L-lactide in the total lactide.

The lactic acid-based polyester used in the present invention has a weight ratio of lactide or a structural unit obtained by dehydration condensation of lactic acid derived from lactic acid to a polyester structural unit composed of a dicarboxylic acid and a diol, which is 99/1 to 1: 1. Fifty
The weight ratio is preferably 90/10 to 50/50 in order to achieve further excellent flexibility.

The method for producing the lactic acid-based polyester used in the present invention will be described below. The method for producing the lactic acid-based polyester used in the present invention is not particularly limited, and specifically, in the presence of a ring-opening polymerization catalyst, lactide is subjected to ring-opening copolymerization and esterification with polyester obtained by dehydration condensation of dicarboxylic acid and diol. Method of obtaining by exchange reaction,

Alternatively, a method in which lactic acid, a dicarboxylic acid and a diol are dehydrated in the presence of a catalyst, or a deglycol condensation or a transesterification reaction is carried out, a polyester obtained by dehydration condensation of a dicarboxylic acid and a diol, and a lactide are subjected to ring-opening polymerization. The obtained polylactic acid or polylactic acid obtained by condensing lactic acid in the presence / absence of a solvent, dicarboxylic acid and di-
For example, there is a method in which a polyester composed of a polyester is obtained by an ester exchange reaction in the presence of an ester exchange catalyst.

Next, the constituent components of the lactic acid type polyester will be described. The dicarboxylic acid component in the lactic acid-based polyester is not particularly limited, but specifically, phthalic acid,
Succinic acid, methylsuccinic acid, 2-methyladipic acid, methylglutaric acid, adipic acid, azelaic acid, sebacic acid, brassic acid, dodecanedicarboxylic acid, cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, dimer Examples thereof include acids, maleic anhydride, fumaric acid and the like.

The diol component, which is a constituent component of the lactic acid-based polyester, may be of any type as long as it is a diol. Specific examples include ethylene glycol, propylene glycol, 1,2-butylene glycol and 1,3-butylene. Glycol, 1,4-butylene glycol, 1,
4-pentanediol, 1,5-pentanediol,
2,4-pentanediol, hexamethylene glycol, octanediol, neopentyl glycol, cyclohexanedimethanol,

Xylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tripropylene glycol, polyethylene glycol, polypropylene glycol, dibutanediol, polytetramethylene glycol, 3-hydroxypivalyl pivalate ethylene glycol, hydrogenated bisphenol A
Etc.

Of the diols and dicarboxylic acids that are the constituent components of the polyester used in the present invention, aliphatic diol acids and aliphatic dicarboxylic acids are particularly preferred because they are excellent in hydrolyzability, biodegradability and flexibility. Further, those having a branched chain are more preferable because of excellent transparency, and polyalkylene glycol as an aliphatic diol component has characteristics of excellent rigidity. Therefore, these can be appropriately selected and used according to the required characteristics of the application.

Since the lactic acid-based polyester used in the present invention is excellent in heat resistance and moldability, it has a weight average molecular weight of 2
It is preferably from 10,000 to 400,000, and more preferably from 50,000 to 350,000. Further, the melting point in DSC is 70 ° C to 20 ° C.
It is 0 ° C, preferably 90 ° C to 190 ° C.

Further, in the method for producing a lactic acid-based polyester containing a high-molecular weight agent used in the present invention, the addition of the high-molecular weight agent may be any step such as a production step or a processing step of the lactic acid-based polyester, and is particularly limited. Not something to do. As the high molecular weight agent used in the present invention, a polyvalent carboxylic acid,
A metal complex, an acidic phosphoric acid ester, an epoxy compound and an isocyanate are preferably used alone or as a mixture.

As the polycarboxylic acid, (anhydrous) maleic acid, (anhydrous) trimellitic acid, (anhydrous) pyromellitic acid, cyclopentanetetracarboxylic dianhydride, EDT
A, Epicron 44 manufactured by Dainippon Ink and Chemicals, Inc.
00 and the like are preferable. Further, as the metal complex, lithium formate, sodium methoxide, potassium propionate,
Magnesium ethoxide, calcium propionate, manganese acetylacetonate, cobalt acetylacetonate,

Zinc acetylacetonate, cobalt acetylacetonate, iron acetylacetonate, aluminum acetylacetonate, aluminum acetylacetonate, tetrabutoxytitanium, aluminum isopropoxide, aluminum-di-n-butoxide-
Mono-ethyl acetoacetate, aluminum-iso-
Propoxoxide-mono-ethylacetoacetate and the like are preferable, and a divalent or higher valent metal complex is particularly preferable.

Examples of the acidic phosphoric acid ester include monomethyl phosphate, monoisopropyl aphosphate, monobutyl phosphate and mono-2-ethylhexyl phosphate.
, Monoisodecyl phosphate, dimethyl phosphate
, Diisopropyl aphosphate, di-2-ethylhexyl phosphate, diisodecyl phosphate, lauryl phosphoric acid, stearyl phosphoric acid and the like are preferable. In addition, a polyhydric alcohol such as trimethylolpropane or pentaerythritol may be included as a constituent component.

As the epoxy compound, glycidyl ethers such as bisphenol A type diglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, terephthalic acid diglycidyl ether, tetrahydrophthalic acid diglycidyl ether, o -Phthalic acid diglycidyl ester, 3,4-epoxycyclohexylmethyl-3,4-
Epoxy cyclo acid carboxylate, bis (3,4-epoxycyclohexyl) adipate, tetradecane-
1,14-dicarboxylic acid glycidyl ester and the like are preferable.

As the isocyanate, hexamethylene diisocyanate, 2,4-tolylene diisocyanate, 2,5-tolylene diisocyanate, toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, isophorone diisocyanate, hydrogenation Diphenylmethane diisocyanate,

A diisocyanate-modified polyether,
A urethane bond such as a polyester modified with diisocyanate, a compound modified with a difunctional isocyanate to a polyhydric alcohol, a polyether modified with a polyvalent isocyanate, a polyester modified with a polyvalent isocyanate, or a mixture thereof is preferable. Among these high molecular weight agents, polyvalent carboxylic acids, metal complexes and acidic phosphoric acid esters are preferable from the viewpoint of safety of the obtained lactic acid-based polyester, and aliphatic compounds are preferable from the viewpoint of biodegradability.

The addition amount of the high molecular weight agent used in the present invention is 0.0 with respect to the total amount of the structural unit obtained by dehydration condensation of lactic acid and the polyester structural unit of dicarboxylic acid and diol.
It is preferably from 0 to 5 parts by weight, more preferably from 0.01 to 2 parts by weight. If the amount exceeds 5 parts by weight, the lactic acid-based polyester is gelated or colored, which is not preferable. If the amount is less than 0.001 part by weight, sufficient effects cannot be recognized for reducing the residual volatile content in the lactic acid-based polyester and suppressing the decrease in molecular weight in the molding process.

In the production of the lactic acid-based polyester of the present invention, in addition to lactic acid, a cyclic dimer of hydroxy acid such as glycolide or an intramolecular lactide, particularly ε-caprolactone, γ-valerolactone, γ-undeca, is used as a copolymerization component. Cyclic esters such as lactone and β-methyl-δ-valerolactone, α-hydroxycarboxylic acid, polyhydric alcohol, cyclic ester compounds other than lactide, and the like may be contained. The timing of addition is not particularly limited, but it is particularly preferable to produce a polyester composed of a dicarboxylic acid and a diol, or to produce a lactic acid-based polyester by copolymerizing the polyester and lactide.

The laminated paper of the present invention will be described below. Examples of the paper used in the present invention include kraft paper, roll paper, art paper (coated paper) carton paper, glassine paper, Kurupak paper, paperboard, and the like.
It is not particularly limited. In some cases, the surface may be treated by corona discharge or the like to improve the adhesiveness.

As the method for producing the laminated paper of the present invention, generally used production methods such as extrusion lamination, dry lamination and wet lamination can be used. Also, the intended lamination paper can be obtained by coating the paper with lactic acid-based polyester as an emulsion solution or lactic acid-based polyester solution and drying with hot air.

The laminated paper of the present invention may have a lactic acid type polyester layer on one side or both sides of the paper, or may have a sandwich shape in which the lactic acid type polyester layer has paper on both sides. Further, another biodegradable resin may be further provided between the lactic acid-based polyester and the paper or on the lactic acid-based polyester layer. Further, the heat resistance of the laminated paper can be improved by subjecting it to a heat treatment after the manufacturing process and the end of the manufacturing.

The heat resistance can be adjusted by the heat treatment conditions, and by the kind and addition amount of the nucleating agent. The heat treatment conditions are 60 ° C. to 150 ° C. and within 60 minutes, preferably 80 ° C. to 1
Within 10 minutes at 20 ° C. As a nucleating agent, sodium acetate, sodium methoxide, sodium stearate, magnesium ethoxide, calcium propionate, barium acetate, manganese acetylacetonate, cobalt acetylacetonate, zinc acetylacetonate.
, Iron acetylacetonate, and nitrifying iodine are preferable, and the addition amount thereof is 0.1 to 5%, preferably 0.5 to 3%.

Applications of the laminated paper of the present invention include daily sundries, food containers, industrial materials, industrial supplies and the like. In particular, since it is excellent in flexibility, oil resistance and safety, it is particularly promising for food packaging.

The laminated paper obtained by the present invention has good hydrolyzability and biodegradability, and after being used as a packaging material or the like, if it is discarded in the soil or dumped in the sea, hydrolysis, microorganisms, etc. Undergo decomposition by. Degradation in seawater also deteriorates the strength of the resin within a few months, and it can be degraded over a longer period of time without maintaining its outer shape. In addition, when the waste paper is repulped, it can be quickly decomposed under conditions such as alkali and easily separated and removed from the paper.

[0035]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. All parts in the examples are on a weight basis unless otherwise specified.

In the flexibility test, the test piece was bent and the bent state was evaluated as follows. ⊚: Very good ∘: Good ∘: The sample has creases ×: The resin layer of the sample appears.

In the oil resistance test, a coated paper was drawn on a smooth surface, a test piece was placed on the coated paper, anhydrous turpentine oil was dropped, and the time when the turpentine oil penetrated the coated paper was evaluated. The hydrolysis test was carried out by immersing a 10 cm × 10 cm laminated paper sample in a 4% aqueous sodium hydroxide solution at a temperature of 95 ° C. for 2 hours with stirring. The sample condition was evaluated according to the following four grades.

⊚: The test piece was in a state where the original shape was not retained. ○: The original shape is retained but it is brittle. Δ: A change is recognized, but the decomposition has not progressed to the point of decomposition. X: No change

The biodegradability test was carried out by Shinki Gosei Co., Ltd., a composting container Tombo Miracle Component 100 with a capacity of 100 liters.
Install the mold outdoors and put 50kg of garbage into it.
A sample of laminated paper having a size of 10 cm × 10 cm was placed, and then garbage was put into a thickness of about 5 cm. 500 g of Nyxaminone, a fermentation accelerator manufactured by Aron Kasei Co., was sprinkled thereon. One month after the start of the test, the test piece was taken out and evaluated in the following four stages.

⊚: It was shattered to a state where the original shape was not retained. ○: The original shape was retained, but it was fragile. Δ: Changes were observed, but decomposition did not proceed to the place where it collapsed. ×: Complete change. None

Reference Example 1 Polyester (50 mol% of succinic acid component, 25 mol% of 1,4-butanediol component,
25 mol% of ethylene glycol component and weight average molecular weight of 2
90 parts of L-lactide and 15 parts of toluene as a solvent were added to 10 parts of 10,000 (polystyrene equivalent), and both were melted and mixed at 170 ° C. for 1 hour under an inert gas atmosphere, and octanoic acid was used as a catalyst. 0.03 parts of tin was added and reacted for 5 hours.

After the reaction product was taken out, cooled and pelletized,
Volatile components were removed at 200 ° C. and 1 mmHg. The lactic acid-based polyester obtained is translucent and has a weight average molecular weight of 1.
The melting point was 70,000 (converted to polystyrene) and DSC was 169 ° C. (This is referred to as Resin A.) Further, 15 g of Resin A is dissolved in 85 g of chloroform, and this solution is applied onto a base with an applicator, and then 16
After drying at 0 ° C. for 10 minutes, a film having a thickness of 20 μm was obtained.

Reference Example 2 Polyester (50 mol% succinic acid component, 25 mol% ethylene glycol component, 25 mol% polyethylene glycol component having a molecular weight of 1000 and weight average molecular weight of 20,000 (in terms of polystyrene)) 1
0 parts, 78 parts L-lactide and 12 parts DL-lactide
Parts and 15 parts of toluene as a solvent, and both were melted and mixed at 170 ° C. for 1 hour in an inert gas atmosphere, and 0.03 parts of tin octoate was added as a catalyst and reacted for 5 hours, followed by lauryl phosphorus. 0.1 part by weight of acid was added and reacted at the same temperature for 1 hour.

After cooling and pelletizing the obtained lactic acid-based polyester, volatile components were removed at 200 ° C. and 1 mmHg. The lactic acid-based polyester obtained was transparent and had a weight average molecular weight of 180,000 (in terms of polystyrene), and a melting point by DSC of 165 ° C. Furthermore, 15 g of Resin B is dissolved in 85 g of chloroform, and this solution is applied onto a substrate with an applicator to prepare 16
After drying at 0 ° C. for 10 minutes, a film having a thickness of 20 μm was obtained.

Reference Example 3 Polyester (50 mol% sebacic acid component, 50 mol% propylene glycol component, weight average molecular weight 20,000 (converted to polystyrene)) 2
0.15 parts of EDTA was added to 0 part of the mixture, and the mixture was stirred at 200 ° C. for 3 hours to cause a reaction.
(Polystyrene conversion), 80 parts of L-lactide and 15 parts of toluene as a solvent are added, and both are melted and mixed at 170 ° C. for 1 hour in an inert gas atmosphere, and tin octoate is used as a catalyst in an amount of 0. Addition of 03 parts and reaction for 6 hours.

After taking out, cooling and pelletizing, 200
Volatile components were removed at 1 ° C and 1 mmHg. The lactic acid-based polyester obtained was transparent and had a weight average molecular weight of 150,000.
0 (polystyrene conversion), melting point in DSC was 161 ° C. (Resin C) Further, 15 g of Resin C is dissolved in 85 g of chloroform,
Then, this solution was applied onto a substrate with an applicator and dried at 160 ° C. for 10 minutes to obtain a film having a thickness of 20 μm.

Reference Example 4 Aliphatic polyester (50 mol% sebacic acid component, 10 mol% propylene glycol component, polypropylene glycol (weight average molecular weight 20)
00) component 40 mol%, weight average molecular weight 20,000
(Polystyrene conversion) 20 parts, L-lactide 80
And 15 parts of toluene as a solvent were added and melted and mixed at 170 ° C. for 1 hour in an inert gas atmosphere, and 0.03 part of tin octoate was added as a catalyst and reacted for 5 hours.

After taking out, cooling and pelletizing, 200
Volatile components were removed at 1 ° C. and 1 mmHg. The weight average molecular weight was 170,000 (in terms of polystyrene), and the melting point by DSC was 169 ° C. (Resin D) Furthermore, 15 g of Resin D is dissolved in 85 g of chloroform,
Then, this solution was applied onto a substrate with an applicator and dried at 160 ° C. for 10 minutes to obtain a film having a thickness of 20 μm.

Reference Example 5 After reacting for 5 hours under the same charge and reaction conditions as in Reference Example 4,
0.5 part of aluminum isopropoxide was added and the reaction was continued for another 0.5 hour. After taking out, cooling and pelletizing,
Volatile components were removed at 130 ° C. and 1 mmHg. The lactic acid-based polyester obtained is transparent and has a weight average molecular weight of 230,
000 (polystyrene equivalent), melting point in DSC is 172
° C. (Resin E) Further, as in Reference Example 1, a film having a thickness of 20 μm was prepared by using 15 g of the resin E.

(Reference Example 6) 80 parts of poly L-lactide manufactured by Purac and poly DL-lactide 2 manufactured by Purac
Part 0 is a twin-screw extruder manufactured by Toyo Seiki Seisakusho (model: Labo Plastomill 2D25WS, screw: diameter 26 mm, L
/ D = 25), melted and kneaded, and pelletized. The lactic acid-based polyester obtained had a weight average molecular weight of 130,000.
The melting point in DSC was 0 ° C (converted to polystyrene) and was 160 ° C. (Resin F) Further, as in Reference Example 1, a film having a thickness of 20 μm was prepared by using 15 g of the resin F.

Example 1 A 20 μm film of Resin A obtained in Reference Example 1 was melted on a woodfree paper having a basis weight of 65 g / m ² at a temperature of 170 ° C. and 30 kg / cm ² for 10 seconds. It pressure-bonded and the laminated paper was produced. The resulting laminated paper was soft and uniformly smooth.

Example 2 Resin B of Reference Example 2 20 μm
The same operation as in Example 1 was performed using the film No. 1.

Example 3 20 μm of Resin C of Reference Example 3
The same operation as in Example 1 was performed using the film No. 1.

Example 4 Resin D of Reference Example 4 20 μm
The same operation as in Example 1 was performed using the film No. 1.

Example 5 Resin E of Reference Example 5 20 μm
The same operation as in Example 1 was performed using the film No. 1.

Comparative Example 1 The same operation as in Example 1 was performed using the 20 μm film of Resin F of Reference Example 6. Table 1 shows the evaluation results of the examples and comparative examples.

[0057]

[Table 1]

[0058]

INDUSTRIAL APPLICABILITY The present invention can provide a laminated paper which has sufficient flexibility and oil resistance, as well as hydrolyzability and excellent biodegradability and which is suitable for recycling waste paper.

Claims (6)

[Claims] 1. A weight average molecular weight of 20,000 to 400,000 including a structural unit obtained by dehydration condensation of lactic acid and a polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol, and a melting point in DSC of 70 ° C. to 200 ° C. Lactic acid polyester laminated paper consisting of lactic acid polyester and paper. 2. The lactic acid according to claim 1, wherein the weight ratio of the structural unit obtained by dehydration condensation of lactic acid and the polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol is 99/1 to 50/50. Type polyester laminated paper. 3. The lactic acid-based polyester contains a structural unit obtained by dehydration condensation of lactic acid, a polyester structural unit obtained by dehydration condensation of dicarboxylic acid and diol, and a structural unit of a high molecular weight agent. Alternatively, the lactic acid-based polyester laminated paper according to item 2. 4. The lactic acid-based polyester laminated paper according to claim 1, wherein the dicarboxylic acid and diol of the lactic acid-based polyester are an aliphatic dicarboxylic acid and an aliphatic diol. 5. The lactic acid-based polyester laminate paper according to claim 1, wherein the dicarboxylic acid and diol of the lactic acid-based polyester are a dicarboxylic acid having a branched chain and a diol. 6. The lactic acid-based polyester diol is a polyalkylene glycol.
Lactic acid-based polyester laminated paper according to any one of 3.