JPH09249868A - Biodegradable adhesive and production of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a biodegradable adhesive consisting of a specific aliphatic polyester as a main component, excellent in adhesion and biodegradability, completely decomposed and disappearing in the natural world, capable of reducing an effect to an environment and useful for an adhesion in processing the materials such as a film, a formed material, etc. SOLUTION: This biodegradable adhesive contains an aliphatic polyester having ester parts of formula I [R1 , R2 are H or methyl; (m), (n) are each an integer; (p) is a molar fraction of the ester part contained in the aliphatic polyester copolymer]and formula II [(l) is an integer;(q) is a molar fraction of the ester part contained in the aliphatic polyester copolymer and is >=0.01] by satisfying a relationship of the equation: (p)+(q)=1, as a main component. The adhesive is obtained e.g. by making an aliphatic polyester obtained by performing a polycondensation of an aliphatic dicarboxylic acid (anhydride) component with a diol component, as a molten state and adding a diepoxy compound.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a biodegradable adhesive consisting of a polymer compound that is biodegradable by microorganisms in the natural world, and particularly to a biodegradable film, molded product, textile product or the like. The present invention relates to a biodegradable adhesive used for bonding various materials and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, plastic products occupy a large part of wastes which are considered to be an environmental problem, and are pointed out as materials which are extremely difficult to process due to their characteristics which do not decompose semi-permanently. From such social needs, Japanese Patent Application Laid-Open Nos. 57-150393, 59-220192, and 5-10573 are disclosed.
6, JP-A-5-148352, JP-A-5-1
Biodegradable plastics that can be naturally decomposed by microorganisms in the soil have been developed, as disclosed in Japanese Patent Publication No. 79016, for example, biopolyester (trade name) of Microorganism Polyester of Seneca Co., Ltd. in England, Showa High Polymer Co., Ltd. Co., Ltd.'s aliphatic polyester-based bionole (trade name), Shimadzu's polylactic acid-based aliphatic polyester-based lacty (trade name), Novamont Italy's starch and modified PVA Mixed Matterby (trade name) or Novon (trade name) and Deglaster (trade name) of Ecostar, Inc. in the United States have been commercialized. Since these biodegradable resins are generally insoluble in general-purpose solvents, they cannot be used for applications other than melt molding such as injection molding, and can also be used as hot melt adhesives. However, the function as an adhesive, particularly the adhesive strength, was insufficient, and it was not suitable for the application.

[0003]

As described above, biodegradable resins have few products suitable for various uses such as adhesives,
In addition to film and molding materials, conventional non-biodegradable materials have to be used. In particular, adhesives are essential materials for processing such as laminating, laminating, and laminating various base materials such as plastic and paper. For this reason,
Even if it is processed using paper, which is a natural material, as an environmentally friendly product, the conventional synthetic polymer resin is used for the adhesive, so that the entire product decomposes and disappears in the natural world with biodegradability. It was not possible to provide products that were compatible with the environment.

Therefore, an adhesive using an aliphatic polyester resin has been investigated, and it has an adhesive strength that can be used for processing such as laminating, laminating and laminating various base materials such as plastic and paper, and has an adhesive strength. It is an object of the present invention to provide a biodegradable adhesive which itself has biodegradability and a method for producing the same.

[0005]

The present invention has been made to achieve the above object, and the invention described in claim 1 is the following general formula (1),

[0006]

Embedded image

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, m and n are integers, and p is represented by the general formula (1) contained in the aliphatic polyester copolymer. And the following general formula (2):

[0008]

[Chemical 6]

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, l is an integer, and q is an ester moiety represented by the general formula (2) contained in the aliphatic polyester copolymer. The molar fraction of is expressed as follows: q ≧ 0.01, p + q =
It is one. ) Is a biodegradable adhesive characterized by having an aliphatic polyester having an ester portion as a main component as a main component.

The invention described in claim 2 is the following general formula (1):

[0011]

Embedded image

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, m and n are integers, and p is represented by the general formula (1) contained in the aliphatic polyester copolymer. And the following general formula (2):

[0013]

Embedded image

(In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, l is an integer, and q is an ester moiety represented by the general formula (2) contained in the aliphatic polyester copolymer. The molar fraction of is expressed as follows: q ≧ 0.01, p + q =
It is one. ) A biodegradable adhesive containing an aliphatic polyester having an ester portion as a main component, which is obtained by polycondensing an aliphatic dicarboxylic acid or its acid anhydride component and a diol component It is a method for producing a biodegradable adhesive, which is obtained by making polyester in a molten state and adding a diepoxy compound.

The invention of claim 3 is the method for producing a biodegradable adhesive according to claim 1, wherein the aliphatic polyester 1
0.3 to 1 of the diepoxy compound relative to 100 parts by weight.
It is characterized by being added in an amount of 5 parts by weight.

According to a fourth aspect of the present invention, in the method for producing a biodegradable adhesive according to the first aspect, the aliphatic polyester is a molar composition of an aliphatic dicarboxylic acid or an acid anhydride component thereof and the diol component. Ratio is from 1.0: 1.0
It is obtained by a polycondensation reaction in the range of 1.0: 0.8.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
In the present invention, both terminal groups of the aliphatic polyester are rich in carboxylic acid, and in a state where the number of terminal groups is reduced, an amount of diepoxy compounds corresponding to the terminal groups are melt-mixed and reacted. Since it reacts with the carboxylic acid at the end of the group polyester, the polymers are linked together, and along with this linking, highly polar hydroxyl groups can be introduced into the polyester structure of the main chain in a bendant form, thereby improving the adhesive strength. Is. That is, according to the present invention, the composition of the resin constituting the aliphatic polyester adhesive having biodegradability does not have a structure in which degradability by natural microorganisms such as urethane bond is hardly recognized. It is possible to obtain a completely biodegradable, highly environmentally friendly adhesive composed only of a compound composed only of carbon, hydrogen and oxygen atoms.

A high-viscosity stirrer can be used for synthesizing the biodegradable adhesive of the present invention described below, and its type is not particularly limited. In the present invention, an aliphatic polyester is produced by a polycondensation reaction of an aliphatic dicarboxylic acid or an acid anhydride thereof and a diol, and as the former aliphatic dicarboxylic acid or an acid anhydride thereof, succinic acid, adipic acid, suberic acid, Examples thereof include sebacic acid, dodecanedioic acid, cyclohexanedicarboxylic acid and their anhydrides. Particularly preferred is succinic acid or succinic anhydride, and when these are used, the melting point of the aliphatic polyester produced can be increased. If necessary, it is also possible to use a mixture of two or more of the above-mentioned aliphatic dicarboxylic acids or their acid anhydrides. The latter diols include ethylene glycol and 1,3-
Propanediol, 1,4-butanediol, 1,3-
Butanediol, 1,5-pentanediol, 1,6-
Hexanediol, 1,7-heptanediol, 1,8
-Octanediol, 1,10-decanediol and the like. Particularly preferably, when the number of methylene chains between the diols is even, the melting point of the aliphatic polyester produced becomes high, and therefore it is preferable when used as a hot melt adhesive. Further, in combination with aliphatic dicarboxylic acid or its acid anhydride, succinic acid, the melting point of the aliphatic polyester can be 100 ° C. or higher by using ethylene glycol or 1,4-butanediol. If necessary, two or more of the above-mentioned diols may be mixed and used. Also, cycloaliphatic 1,4-cyclohexanedimethanol and the like can be used.

The synthesis of the aliphatic polyester by the polycondensation reaction of the above aliphatic dicarboxylic acid or its acid anhydride and the diol is carried out by the esterification reaction and deglycolization reaction of the above respective components. In the present invention, since the use is an adhesive and not a molding use, it does not need to have a high molecular weight. The production conditions are, for example, a temperature of 160 ° C. to 230 ° C. and a reaction time of 5 to 12 hours in the esterification reaction.
At this time, the molar ratio of the charged composition of the aliphatic dicarboxylic acid or its acid anhydride and the diol is preferably in the range of 1 to 0.8 mol of the diol with respect to 1 mol of the aliphatic dicarboxylic acid. The reason for this is that the aliphatic polyester produced under the condition of increasing the amount of dicarboxylic acid with respect to the diol becomes a carboxylic acid terminal group at the polymer end, and it easily reacts with the diepoxy compound added for imparting adhesiveness. Is.

The deglycolization reaction is carried out, for example, at a temperature of 18
0 ° C to 230 ° C, reaction time 2 to 12 hours, pressure 1 Tor
The organic compound of titanium (eg, titanium isopropoxide,
(Titanium isobutoxide, titanium oxyacetylacetonate, etc.); metal organic acid salts such as zinc, lead, zirconium, etc .; chelate compounds; antimony oxide, etc. can be used, and the catalyst is 0.001 to 100 parts by weight of polyester produced. It is preferably 0.1 part by weight. It should be noted that when the reaction time is lengthened, the molecular weight can be increased, but the number of terminal functional groups is reduced accordingly, so that it is not possible to add a large amount of diepoxy compound that enhances the adhesive force.

The above aliphatic polyester is further added with a diepoxy compound in order to enhance its adhesiveness. This diepoxy compound may be generally commercially available and is not particularly limited. For example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, bisphenol A diglycidyl ether. And the like. In particular, in order to increase the biodegradability of the resin produced, it is preferable to use an aliphatic type. If necessary, the diepoxy compound described above may be added to the
It is also possible to use a mixture of more than one species.

The amount of the diepoxy compound added is 0.3 to 1 with respect to 100 parts by weight of the desired aliphatic polyester.
0 parts by weight is required. If the addition amount is less than 0.3 parts by weight, the effect of addition of the diepoxy compound is poor, and if it exceeds 10 parts by weight, gelation is likely to occur. Regarding the addition of the diepoxy compound to the above aliphatic polyester, it is desirable to carry out the reaction by stirring at about the melting temperature of the above aliphatic polyester for about 2 to 8 hours. At this time, in order to accelerate the reaction, a catalyst can be added if necessary. Examples of this catalyst include metal complexes of acetylacetonate such as Cr, Zr, Ni, and Co, benzyltrimethylammonium chloride, benzyltriethylammonium chloride, benzyldimethylamine, tetraethylammonium tetrafluoroborate, triethanolamineborate, and triethanolamine borate. Examples include ethanolamine titanate, tin octylate, quaternary phosphonium salts, quaternary organic arsonium salts, imidazolium salts, and amine imides.

The aliphatic polyester obtained by the production method of the present invention is obtained by randomly copolymerizing the ester moieties of the above general formulas (1) and (2). A biodegradable adhesive containing this as a main component can be used for bonding various materials such as films, molded products, fibers, etc., for example, it is used at the joint part when molding paper cups, milk packs, etc. It can be used as a melted adhesive, a so-called hot-melt type adhesive, or as an adhesive anchor agent used when laminating various films, or as an adhesive anchor agent dissolved in various solvents, applied to the film and dried. At that time, known additives such as a reinforcing agent, an inorganic or organic filler, a colorant, various stabilizers, and lubricant waxes can be used if necessary.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to specific embodiments. <Example 1> 62 parts by weight of succinic acid, 60 parts by weight of 1,6-hexanediol, 0.07 parts by weight of tetraisopropyl titanate were placed in a four-necked flask equipped with a stirrer, a return condenser, a thermometer, and a gas introduction tube. Then, the temperature was gradually raised to 160 to 200 ° C. in a nitrogen gas stream to carry out an esterification reaction, and finally a deglycolization reaction was carried out at 200 ° C. for about 3 hours under a reduced pressure of 0.5 Torr. 30 parts by weight of this polyester was melted at 180 ° C., 0.9 parts by weight of ethylene glycol diglycidyl ether and 0.036 parts by weight of diethylbenzylamine as a catalyst were added, and the mixture was stirred for about 3 hours, but did not gel, An aliphatic polyester resin was obtained.

[Biodegradability Test] A sheet having a thickness of about 100 μm was produced from this aliphatic polyester resin by hot pressing, and this sheet was placed in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.). Buried to a depth of about 10 cm,
A biodegradability test was carried out by embedding in soil. as a result,
It was confirmed that the buried sheet was completely decomposed and disappeared in about 3 months.

[Adhesiveness Test] The aliphatic polyester resin obtained on one surface of a rolled paperboard (uncoated ivory, 220 g / m ² ) was applied to a T-die melt extrusion method to give 3
They are laminated to a thickness of 0 μm and adhered to a paperboard of the same material by the heat seal adhesion method under the conditions of a hot air temperature of 180 ° C., a pressure of 2 kg / cm ² , and a duration of 2 seconds. It was measured under the conditions of 15 mm and 90 degree peel strength (kg / 15 mm). Table 1 shows the results.
Shown in

<Example 2> Stirrer, return condenser,
In a four-necked flask equipped with a thermometer and a gas introduction tube, 62 parts by weight of succinic acid, 59 parts by weight of 1,6-hexanediol,
Add 0.07 parts by weight of tetraisopropyl titanate,
In a nitrogen gas stream, the temperature is gradually raised to 160 to 200 ° C. to carry out the esterification reaction, and finally 0.5 Torr
Under a reduced pressure of r, the deglycol reaction was performed at 200 ° C. for about 3 hours. 30 parts by weight of this polyester was melted at 180 ° C., 1.94 parts by weight of 1,6-hexanediol diglycidyl ether and 0.07 part by weight of diethylbenzylamine as a catalyst were added and stirred for about 3 hours. An aliphatic polyester resin was obtained without conversion.

[Biodegradability Test] A sheet having a thickness of about 100 μm was produced by hot pressing this aliphatic polyester resin, and this sheet was placed in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.). Buried to a depth of about 10 cm,
A biodegradability test was carried out by embedding in soil. as a result,
It was confirmed that the buried sheet was completely decomposed and disappeared in about 3 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Example 3> A stirrer, a return condenser,
In a four-necked flask equipped with a thermometer and a gas inlet tube, 99.2 parts by weight of succinic acid, 72.1 parts by weight of 1,4-butanediol and 0.11 part by weight of tetraisopropyl titanate were put, and the mixture was put in a nitrogen gas stream. , The temperature is gradually raised to 160 to 200 ° C. to carry out the esterification reaction, and finally 0.5
The deglycol reaction was performed at 200 ° C. for about 3 hours under reduced pressure of Torr. 30 parts by weight of this polyester was melted at 180 ° C., 2.60 parts by weight of ethylene glycol diglycidyl ether and 0.1 part by weight of diethylbenzylamine as a catalyst were added, and the mixture was stirred for about 3 hours, but did not gel, An aliphatic polyester resin was obtained.

[Biodegradability Test] A sheet having a thickness of about 100 μm was produced from this aliphatic polyester resin by hot pressing, and this sheet was placed in the soil (Sugito-cho, Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.). Buried to a depth of about 10 cm,
A biodegradability test was carried out by embedding in soil. as a result,
It was confirmed that the buried sheet was completely decomposed and disappeared in about 3 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Example 4> A stirrer, a return condenser,
In a four-necked flask equipped with a thermometer and a gas inlet tube, 99.2 parts by weight of succinic acid, 72.1 parts by weight of 1,4-butanediol and 0.11 part by weight of tetraisopropyl titanate were put, and the mixture was put in a nitrogen gas stream. , The temperature is gradually raised to 160 to 200 ° C. to carry out the esterification reaction, and finally 0.5
The deglycolization reaction was performed at 200 ° C. for about 4 hours under reduced pressure of Torr. 30 parts by weight of this polyester was melted at 180 ° C., 2.84 parts by weight of propylene glycol diglycidyl ether and 0.1 parts by weight of diethylbenzylamine as a catalyst were added, and the mixture was stirred for about 5 hours, but did not gel. An aliphatic polyester resin was obtained.

[Biodegradability test] A sheet having a thickness of about 100 μm was produced from this aliphatic polyester resin by hot pressing, and the sheet was put in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.). Buried to a depth of about 10 cm,
A biodegradability test was carried out by embedding in soil. as a result,
It was confirmed that the buried sheet was completely decomposed and disappeared in about 3 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

Further, a comparative example will be described and compared with an example of the present invention. <Comparative Example 1> In a four-necked flask equipped with a stirrer, a return condenser, a thermometer, and a gas introduction tube, 62 parts by weight of succinic acid, 60 parts by weight of 1,6-hexanediol, and 0.07 part by weight of tetraisopropyl titanate. In a nitrogen gas stream, the temperature is gradually raised to 160 to 200 ° C to carry out an esterification reaction, and finally a deglycolization reaction is carried out at 200 ° C for about 3 hours under a reduced pressure of 0.5 Torr to obtain a polyester resin. Got

[Biodegradability Test] A sheet having a thickness of about 100 μm was produced by hot pressing this polyester resin,
This sheet was embedded in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.) at a depth of about 10 cm, and a biodegradability test was performed by embedding in the soil. As a result, it was confirmed that the buried sheet was completely decomposed and disappeared in about 3 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Comparative Example 2> Stirrer, return condenser,
In a four-necked flask equipped with a thermometer and a gas inlet tube, 99.2 parts by weight of succinic acid, 72.1 parts by weight of 1,4-butanediol and 0.11 part by weight of tetraisopropyl titanate were put, and the mixture was put in a nitrogen gas stream. , The temperature is gradually raised to 160 to 200 ° C. to carry out the esterification reaction, and finally 0.5
Under a reduced pressure of Torr, a glycol removal reaction was performed at 200 ° C. for about 4 hours to obtain a polyester resin.

[Biodegradability Test] A sheet having a thickness of about 100 μm was produced by hot pressing this polyester resin,
This sheet was embedded in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.) at a depth of about 10 cm, and a biodegradability test was performed by embedding in the soil. As a result, it was confirmed that the buried sheet completely decomposed and disappeared in about 8 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

<Comparative Example 3> Commercially available polycaprolactone resin (Placcel H-5 [trade name] manufactured by Daicel Chemical Industries, Ltd.)
Was used as an adhesive. [Biodegradability test] A sheet having a thickness of about 100 µm was produced by hot pressing this polycaprolactone resin, and this sheet was placed in soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.) at a depth of about 10 cm. It was buried in the soil, and a biodegradability test was performed by embedding it in the soil. As a result, it was confirmed that the buried sheet was completely decomposed and disappeared in about 6 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 4 A commercially available aliphatic polyester resin (Bionore # 1000 [trade name] manufactured by Showa High Polymer Co., Ltd.) was used as an adhesive. [Biodegradability test] A sheet having a thickness of about 100 µm was prepared by hot pressing this aliphatic polyester resin, and this sheet was placed in soil (Sugito-cho, Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.) at a depth of about It was embedded in 10 cm and a biodegradability test was performed by embedding it in soil. As a result, it was confirmed that the buried sheet was completely decomposed and disappeared in about 1 year. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

Comparative Example 5 An adhesive was prepared using a commercially available polyhydroxybutyrate resin (Biopol [trade name] manufactured by Zeneca). [Biodegradability Test] A sheet having a thickness of about 100 μm is produced by hot pressing this polyhydroxybutyrate resin,
This sheet was embedded in the soil (Sugito-cho, Kita-Katsushika-gun, Saitama Prefecture, Toppan Printing Co., Ltd.) at a depth of about 10 cm, and a biodegradability test was performed by embedding in the soil. As a result, it was confirmed that the buried sheet was completely decomposed and disappeared in about 2 months. [Adhesiveness test] A peelability test was conducted in the same manner as in Example 1, and the results are shown in Table 1.

[0040]

[Table 1]

[0041]

EFFECT OF THE INVENTION According to the biodegradable adhesive and the method for producing the same of the present invention, an adhesive is prepared by melting and mixing a diepoxy compound in an amount corresponding to the terminal groups in a state where the terminal groups of the aliphatic polyester are reduced. It is possible to obtain an aliphatic polyester having excellent properties, and this aliphatic polyester can be used as an adhesive for processing various materials such as films, molded products and fibers, and since it exhibits biodegradability,
It can be completely decomposed and disappeared in the natural world, and the impact on the environment can be reduced. Similarly, it can be used for laminating, laminating, laminating with various base materials such as biodegradable plastics and papers, and it becomes possible to obtain a completely biodegradable article.

Claims (4)

[Claims] 1. The following general formula (1): (In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, m and n are integers, and p is an ester moiety of the general formula (1) contained in the aliphatic polyester copolymer. And the ester portion represented by the following general formula (2): (In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, l is an integer, and q is a molar amount of the ester portion represented by the general formula (2) contained in the aliphatic polyester copolymer. The biodegradable adhesive is characterized in that the main component is an aliphatic polyester having an ester portion represented by q ≧ 0.01 and p + q = 1. 2. The following general formula (1): (In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, m and n are integers, and p is an ester moiety of the general formula (1) contained in the aliphatic polyester copolymer. And the following general formula (2): (In the formula, R ₁ and R ₂ represent a hydrogen atom or a methyl group, l is an integer, and q is a molar amount of the ester portion represented by the general formula (2) contained in the aliphatic polyester copolymer. In the biodegradable adhesive containing an aliphatic polyester having an ester part represented by q ≧ 0.01 and p + q = 1 as a main component, an aliphatic dicarboxylic acid or its A method for producing a biodegradable adhesive, which is obtained by bringing an aliphatic polyester obtained by polycondensing an acid anhydride component and a diol component into a molten state and adding a diepoxy compound. 3. The biodegradable adhesive according to claim 1, wherein the diepoxy compound is added in an amount of 0.3 to 15 parts by weight with respect to 100 parts by weight of the aliphatic polyester. Manufacturing method. 4. The aliphatic polyester has a molar ratio of the charged composition of the aliphatic dicarboxylic acid or its acid anhydride component and the diol component of 1.0: 1.0 to 1.0: 0.
The method for producing a biodegradable adhesive according to claim 1, which is obtained by a polycondensation reaction in the range of 8.