JP4470010B2 - Adhesive composition and composite film for soft packaging material - Google Patents

Description

【００９２】
【表２】

【発明の効果】
本発明の接着剤組成物によれば、その接着剤組成物によって接着された複合フィルムからの内容物中への、接着剤組成物に起因する環状化合物の溶出が、従来のエステル系ウレタン接着剤に比較して、極端に少ないため、食品や飲料などが充填されている場合にも、その食品や飲料などが本来有する臭味を損わせることがなく、また、微量の異物の混入でも問題となるハードディスクなどの電子部品を包装する場合にも、その電子部品が本来有する性能を損わせることがなく、これらを含む各種の産業製品を包装する軟包装材料用複合フィルムを製造するための接着剤として好適に用いることができる。
【００９３】
また、本発明の接着剤組成物は、耐油性に優れるため、レトルトなどの加熱殺菌処理を必要とする油性食品を包装するための複合フィルムに用いても、加熱殺菌処理後の複合フィルムの強度を著しく低下させることがなく、優れた接着強度を保持することができる。
【００９４】
しかも、本発明の接着剤組成物は、軟包装材料用複合フィルムの製造に必要な接着剤の柔軟性を良好に発現するため、複合フィルムの剥離強度の低下を防止することができる。
【００９５】
そのため、本発明の接着剤組成物により接着されている本発明の軟包装材料用複合フィルムは、内容物が本来有する性能を損わせず、また、加熱殺菌処理後の強度低下も少なく、さらには、剥離強度の低下も少ない、軟包装材料用途の複合フィルムとして有効に用いられる。[0001]
BACKGROUND OF THE INVENTION
The present invention is suitable for producing an adhesive composition, specifically, for example, a composite film for flexible packaging materials for packaging foods, beverages, pharmaceuticals and quasi drugs, or electronic parts such as hard disks. The present invention relates to an adhesive composition to be used, and a composite film for a soft packaging material adhered by the adhesive composition.
[0002]
[Prior art]
To date, as flexible packaging materials used for packaging various industrial products such as food, beverages, pharmaceuticals and quasi drugs, or electronic parts such as hard disks, for example, plastic films, metal foils such as aluminum, Composite films obtained by laminating metal vapor-deposited films, silica vapor-deposited films and the like using an adhesive are widely used.
[0003]
As an adhesive used in the production of such a composite film, the two-component reaction type ester urethane adhesive using a combination of polyisocyanate and polyester polyol has the most excellent adhesive performance. Many are used.
[0004]
However, in recent years, research on substances that elute from the composite film into the contents has progressed, and low molecular weight compounds have eluted from the adhesive into the contents, and the causal relationship between these low molecular weight compounds is still clear. However, it has been suggested that the performance inherent in the contents, for example, the odor inherent in foods and beverages, and the possibility of being one of the causes of impairing the performance inherent in electronic components are being suggested. ing.
[0005]
Therefore, it is a laminating adhesive containing polyester polyurethane polyol, and from the composite film bonded by the laminating adhesive, 0.5 mL / cm per unit area of the composite film²The content of the composite film is such that the concentration of the cyclic ester compound or cyclic urethane compound in the extracted water extracted with water is 0.5 ppb or less in terms of dibutyl phthalate measured with a gas chromatograph-hydrogen flame ionization detector. It has been proposed to reduce low molecular weight compounds that elute in a product so as not to impair the performance of the contents (see, for example, Patent Document 1 and Patent Document 2).
[0006]
[Patent Document 1]
JP 2001-107016 A
[Patent Document 2]
JP 2001-1007017 A
[Problems to be solved by the invention]
However, since the laminating adhesive described in Patent Document 1 and Patent Document 2 contains dimer acid as the composition of the polyester polyol, it is excellent in water resistance while lowering oil resistance, and the ester group concentration. For example, when used in a composite film for packaging oily foods that require heat sterilization such as retort, the strength of the composite film is significantly reduced after heat sterilization. It causes a defect.
[0007]
Therefore, for example, it may be possible to improve cohesion by introducing an amide bond into the polyester polyol, but amides derived from aromatic dibasic acids or aliphatic dibasic acids used as ordinary ester raw materials When the bond is introduced, the flexibility of the adhesive necessary for the production of the composite film for soft packaging material is impaired, resulting in a problem that the peel strength is lowered.
[0008]
The present invention has been made in view of such problems, and the object of the present invention is to reduce the low molecular weight compounds eluted in the contents of the composite film without impairing the performance inherent in the contents. In addition, the oil resistance can be improved, and even if the content is oily, it can be prevented from causing a significant decrease in strength, and further, it exhibits good flexibility to prevent a decrease in peel strength. Another object of the present invention is to provide an adhesive composition and a composite film for a soft packaging material adhered by the adhesive composition.
[0009]
[Means for Solving the Problems]
  In order to achieve the above object, the adhesive composition of the present invention comprises a polyisocyanate component and a polyol component, and the polyol component isIncludes polyester unit and polyamide unitPolyester polyamide polyol and / or polyurethane polyester polyamide polyolConsist of,The polyester unit comprises an ester bond obtained by reaction of phthalic acid and / or its alkyl ester with 1,6-hexanediol, an ester bond obtained by reaction of naphthalene dicarboxylic acid and / or its alkyl ester with glycol, and , Including at least one ester bond selected from the group consisting of ester bonds obtained by reaction of dimer acid and glycol as a main ester bond, and the amide bond of the polyamide unit is obtained by reaction of dimer acid and polyamine. An amide bond,From the composite film adhered by the adhesive composition, 0.5 mL / cm per unit area of the composite film²The concentration of the cyclic compound consisting of an amide bond and / or an ester bond in the extracted water extracted with water is 0.5 ppb or less in terms of dibutyl phthalate measured with a gas chromatograph-hydrogen ionization detector. It is a feature.
[0011]
Moreover, in this invention, it is preferable that 10-90 mol% of the carboxyl group of the dimer acid which forms the said amide bond has reacted with the amino group of polyamine.
[0012]
Moreover, in this invention, it is preferable to contain a silane coupling agent further.
[0013]
And the adhesive composition of this invention can be used suitably for manufacture of the composite film for flexible packaging materials.
[0014]
Moreover, this invention also contains the composite film for soft packaging materials adhere | attached by said adhesive composition.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
The adhesive composition of the present invention includes a polyisocyanate component and a polyol component.
[0016]
In the present invention, as the polyisocyanate component, a polyisocyanate cake usually used in the production of polyurethane is used. For example, a polyisocyanate monomer and a derivative thereof are used.
[0017]
Examples of the polyisocyanate monomer include aliphatic diisocyanates such as hexamethylene diisocyanate, such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3. -Or alicyclic diisocyanates such as 1,4-bis (isocyanatomethyl) cyclohexane or mixtures thereof, for example 1,3- or 1,4-xylylene diisocyanate or mixtures thereof, 1,3- or 1,4- Araliphatic diisocyanates such as bis (1-isocyanato-1-methylethyl) benzene or mixtures thereof, for example aromatics such as 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, diphenylmethane diisocyanate Such as isocyanate used.
[0018]
Examples of the derivative of the polyisocyanate monomer include, for example, a polymer of polyisocyanate such as a dimer and a trimer of the above polyisocyanate monomer, for example, the above polyisocyanate monomer, water, Polyisocyanate modified products such as biuret modified products, allophanate modified products, oxadiazine trione modified products obtained by reaction with polyol and carbon dioxide gas, for example, the above-mentioned polyisocyanate monomers, polyols described below and / or Alternatively, a polyol adduct and / or a polyamine adduct obtained by reaction with a polyamine is used.
[0019]
These polyisocyanate components may be used alone or in combination of two or more. Preferably, a polyisocyanate monomer derivative is used, and in particular, an unreacted monomer content of 1% or less is preferably used.
[0020]
In the present invention, the polyol component includes a polyester polyamide polyol containing an amide bond obtained by the reaction of dimer acid and polyamine, and / or a polyurethane polyester polyamide polyol containing an amide bond obtained by the reaction of dimer acid and polyamine. It is out.
[0021]
The polyester polyamide polyol includes a polyester unit and a polyamide unit.
[0022]
  The polyester unit is a unit containing an ester bond, and includes a polybasic acid and / or an alkyl ester thereof.GlycolIt forms by reaction with.
[0023]
  Polybasic acids and / or their alkyl esters areTheTaric acid (eg, orthophthalic acid, isophthalic acid, terephthalic acid, etc.) and / or its alkyl ester, naphthalenedicarboxylic acid (eg, 2,6-naphthalenedicarboxylic acid, etc.) and / or its alkyl ester,and,Dimer acidAt least one selected fromIs used.
[0024]
Heat resistance can be improved by using an aromatic dibasic acid such as phthalic acid and / or its alkyl ester, naphthalenedicarboxylic acid and / or its alkyl ester.
[0026]
In addition, as alkyl ester of polybasic acid, C1-C4 alkyl ester of polybasic acid, Preferably, methyl ester of polybasic acid and ethyl ester of polybasic acid are used.
[0027]
The dimer acid is not particularly limited as long as it is available as an industrial raw material. For example, the dimer acid includes a dimer of an unsaturated fatty acid having 18 carbon atoms as a main component, and in addition, monomeric acid and trimer acid. Those containing, and further, hydrogenated products thereof can be used.
[0028]
  GlycolAs, for example, ethylene glycol, diethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 1,6-hexanediol, 1 , 7-heptanediol, 1,9-nonanediol, cyclohexanedimethanol, 3-methyl-1,5-pentanediol, 3,3′-dimethylolheptane, 2-methyl-1,8-octanediol.WhoUsed. theseGlycolMay be used alone or in combination of two or more.
[0029]
  And these polybasic acids and / or their alkyl estersGlycolPolyester unit formed by reaction with phthalic acid and / or its alkyl ester, preferably with isophthalic acid and / or its alkyl ester1, 6-hexanediol, the cyclic ester compound of 2 molecules of isophthalic acid and 2 molecules of 1,6-hexanediol produced by the reaction of isophthalic acid and 1,6-hexanediol elutes through the film. It is difficult to maintain the original performance of the contents. The main chain in glycol refers to a molecular chain sandwiched between two hydroxyl groups, and the main chain carbon number refers to the number of carbons present in the molecular chain.
[0030]
For example, when isophthalic acid and / or its alkyl ester is reacted with a glycol having a main chain carbon number of 5 or less, a cyclic ester compound of 2 molecules of isophthalic acid and 2 molecules of glycol is produced, and this cyclic ester compound May elute through the film, and when isophthalic acid and / or its alkyl ester is reacted with glycol having a main chain carbon number of 8 or more, a cyclic ester compound of one molecule of isophthalic acid and one molecule of glycol This cyclic ester compound may be eluted through the film.
[0031]
Moreover, if naphthalene dicarboxylic acid and / or its alkyl ester is used, the cyclic ester compound of naphthalene dicarboxylic acid and glycol produced by the reaction of naphthalene dicarboxylic acid and glycol does not elute through the film, and the contents are not The inherent performance can be maintained satisfactorily.
[0032]
In addition, if dimer acid is used, the cyclic ester compound of dimer acid and glycol produced by the reaction of dimer acid and glycol does not elute through the film, and the performance inherent in the contents is maintained well. Can do.
[0033]
  Therefore, in the present invention, the polyester unit in the polyester polyamide polyol includes phthalic acid and / or its alkyl ester.1,6-hexanediolThe main ester bond is an ester bond obtained by reacting with diphthalic acid and glycol, an ester bond obtained by reacting naphthalenedicarboxylic acid and / or its alkyl ester with glycol, and an ester bond obtained by reacting dimer acid with glycol.The
[0034]
  The polyamide unit is a unit containing an amide bond, and in the present invention,The amide bond of the polyamide unit isAmide bond obtained by reaction of dimer acid with polyamineInThe
[0035]
By including a polyamide unit in the polyol component, the cohesive force of the adhesive composition can be improved, and a significant decrease in the strength of the composite film after the heat sterilization treatment can be prevented.
[0037]
In addition, the polyamine is not particularly limited, but examples thereof include aliphatic diamines such as ethylenediamine, propylenediamine, and hexamethylenediamine, such as isophoronediamine, dicyclohexylmethane-4,4′-diamine, 1,3-, and 1,4. -Alicyclic diamines such as bis (aminomethyl) cyclohexane or mixtures thereof, for example 1,3- or 1,4-xylylenediamine or mixtures thereof, 1,3- or 1,4-bis (1-amino- Araliphatic diamines such as 1-methylethyl) benzene or mixtures thereof, such as 2,4- or 2,6-tolylenediamine or mixtures thereof, aromatic diamines such as diphenylmethanediamine, such as diethylenetriamine, triethylenetetramine, Tetraethylene pen , Pentaethylene hexamine, 2,2' such polyfunctional polyamines having an amino group three or more, such as diamino diethylamine is used in practice, the boiling point, is used more than 180 ° C.. These polyamines may be used alone or in combination of two or more. Preferably, aliphatic diamine and alicyclic diamine are used.
[0038]
  AndTheIf dimer acid is used in the reamide unit, the cyclic amide compound of dimer acid and diamine produced by the reaction of dimer acid and diamine does not elute through the film, and the performance inherent in the contents is improved. Can be maintained. In addition, the composite film can exhibit good flexibility and prevent a decrease in peel strength.
[0039]
Therefore, in the present invention, the polyamide unit in the polyester polyamide polyol has an amide bond obtained by the reaction of dimer acid and aliphatic diamine and / or an amide bond obtained by the reaction of dimer acid and alicyclic diamine. , It is preferably contained as a main amide bond.
[0040]
In such a polyamide unit, it is preferable that 10 to 90 mol% of the carboxyl group of the dimer acid is reacted with the amino group of the polyamine.
[0041]
In the present invention, the polyester polyamide polyol is not particularly limited as long as the polyester unit and the polyamide unit described above are included, and can be synthesized by a known method.
[0042]
  That is, such a polyester polyamide polyol includes, for example, a polybasic acid and / or an alkyl ester thereof,Glycol (including 1,6-hexanediol)And polyamine can be obtained by reacting at 160 to 250 ° C. in an inert gas atmosphere.
[0043]
  In this case, for example, first, a polybasic acid (excluding dimer acid) and / or an alkyl ester thereof,GlycolAnd the polyamine are reacted and, if necessary, water or alcohol formed is distilled off, then dimer acid is converted into polybasic acid (excluding dimer acid) and / or its alkyl ester,GlycolIn addition to the reaction system containing polyamine and polyamine, a polyester polyamide polyol can be obtained by further reaction at 160 to 250 ° C. in an inert gas atmosphere.
[0044]
  Also, for example, first, a polybasic acid (excluding dimer acid) and / or an alkyl ester thereof,GlycolIs reacted at 160 to 250 ° C. in an inert gas atmosphere to synthesize a polyester polyol, and if necessary, water or alcohol produced is distilled off, and then synthesized (or synthesized) polyester. A polyester polyamide polyol can also be obtained by adding a dimer acid and a polyamine to a polyol and further reacting at 160 to 250 ° C. in an inert gas atmosphere.
[0045]
  For example, first, dimer acid and polyamine are reacted at 160 to 250 ° C. in an inert gas atmosphere to synthesize a polyamide polycarboxylic acid having a carboxyl group at the molecular end. Separately, polybasic acid andGlycolAre reacted at 160 to 250 ° C. in an inert gas atmosphere to synthesize a polyester polyol having a hydroxyl group at the molecular end, and if necessary, water or alcohol to be produced is distilled off. Then, by blending the synthesized (in the middle of synthesis) polyester polycarboxylic acid with the synthesized (in the middle of synthesis) polyester polyol, and further reacting at 160 to 250 ° C. in an active gas atmosphere, A polyester polyamide polyol can also be obtained.
[0046]
  In any of the methods described above, a polybasic acid and / or an alkyl ester thereof is used so that the molecular terminal of the finally obtained polyester polyamide polyol is substantially a hydroxyl group,GlycolThe mixing ratio of polyamine can be selected as appropriate.
[0047]
Furthermore, in the present invention, the hydroxyl group at the molecular end of the polyester polyamide polyol thus obtained may be reacted with a polybasic acid anhydride to acid-modify the molecular end. Such acid modification may be performed by a known method using, for example, a polybasic acid anhydride such as trimellitic anhydride, pyromellitic anhydride, phthalic anhydride, maleic anhydride, or the like.
[0048]
And in this invention, if the polyester polyamide polyol obtained in this way is included as a raw material, you may use polyester polyamide polyol as a polyol component as it is, and polyester polyamide polyol is chain extension with polyisocyanate. By reacting, it may be used as a polyurethane polyester polyamide polyol, and furthermore, it may be used as a high molecular weight polyester polyamide polyol by subjecting the polyester polyamide polyol to a condensation reaction. If the polyester polyamide polyol is made to have a high molecular weight by a chain extension reaction or a condensation reaction, desired physical properties can be expressed in the resulting adhesive composition. In addition, when using polyester polyamide polyol as a polyol component as it is, it is preferable that the number average molecular weight is 500-3000 or less, for example.
[0049]
When the polyester polyamide polyol is subjected to a chain extension reaction with the polyisocyanate, the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester polyamide polyol is less than 1, preferably 0.5 to 0.95. In such a ratio, the polyester polyamide polyol and the polyisocyanate may be urethanized by a known method. The chain extension reaction is not particularly limited, and the above-described polyisocyanate is used, and aliphatic diisocyanate and alicyclic diisocyanate are preferably used.
[0050]
The polyurethane polyester polyamide polyol thus obtained has a number average molecular weight of preferably about 1,000 to 100,000, more preferably about 5,000 to 20,000.
[0051]
In such chain extension reaction, the above-described polyol may be reacted with polyisocyanate together with the polyester polyamide polyol. In this case as well, the ratio in which the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate to the polyester polyol and the hydroxyl group of the polyol is less than 1, preferably 0.5 to 0.95. React with.
[0052]
Further, when the polyester polyamide polyol is subjected to a chain elongation reaction, it is preferable that the unreacted glycol in the polyester polyamide polyol is 0.1% by weight or less. If the unreacted glycol in the polyester polyamide polyol exceeds 0.1% by weight, depending on the type of polyisocyanate, when the polyester polyamide polyol and the polyisocyanate are reacted, the cyclic urethane reacts with the unreacted glycol. This produces a compound that may elute through the film. In addition, the unreacted glycol content in such a polyester polyamide polyol can be determined by, for example, a gas chromatographic method (hydrogen flame ionization detector). In order to make the unreacted glycol in the polyester polyamide polyol 0.1% by weight or less, for example, a known removal operation such as removing the unreacted glycol under reduced pressure may be used.
[0053]
When the polyester polyamide polyol is subjected to a condensation reaction, the polyester polyamide polyol obtained as described above may be condensed, for example, at 160 to 250 ° C. under reduced pressure.
[0054]
The high molecular weight polyester polyamide polyol thus obtained has a number average molecular weight of preferably about 3000 to 100000, more preferably about 5000 to 20000.
[0055]
Then, the above-described polyisocyanate component and a polyol component including the polyester polyamide polyol thus obtained (including a polyurethane polyester polyamide polyol and / or a high molecular weight polyester polyamide polyol containing polyester polyamide polyol as a raw material) are blended. By this, the adhesive composition of the present invention can be obtained.
[0056]
The ratio of the polyisocyanate component and the polyol component is such that the equivalent ratio of the isocyanate group in the polyisocyanate component to the hydroxyl group in the polyol component (NCO / OH) is 0.4 or more and 10.0 or less, It is preferably 5 or more and 5.0 or less.
[0057]
The adhesive composition of the present invention may further contain a silane coupling agent.
[0058]
As a silane coupling agent, structural formula R-SiX₃Or R-Si (R ') X₂(Wherein R represents an organic group having a vinyl group, an epoxy group, an amino group, an imino group, an isocyanate group or a mercapto group, R ′ represents a lower alkyl group, and X represents a methoxy group, an ethoxy group or As long as it is represented by chlorosilane, such as vinyltrichlorosilane, such as N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ -Aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-propylmethyldimethoxysilane, n- (dimethoxymethylsilylpropyl) ethylenediamine, n- (triethoxysilylpropyl) ethylenediamine, N-phenyl-γ-amino Aminosilanes such as propyltrimethoxysilane, for example γ-glycidoxypropylene Epoxy silanes such as trimethoxysilane, γ-glycidoxypropyltriethoxysilane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, di (γ-glycidoxypropyl) dimethoxysilane, such as vinyltriethoxy Examples thereof include vinyl silanes such as silane, for example, isocyanate silanes such as 3-isocyanatopropyltrimethoxysilane and 3-isocyanatopropyltriethoxysilane. These silane coupling agents may be used alone or in combination of two or more.
[0059]
Further, the adhesive composition of the present invention includes additives for the purpose of imparting adhesiveness such as phosphorus oxyacids or derivatives thereof, and known catalysts for controlling the curing reaction, etc. You may mix | blend in the range which does not inhibit the performance of a composition.
[0060]
The adhesive composition of the present invention thus obtained is not particularly limited and can be used as a binder or an adhesive for the purpose of adhesion. In particular, the composite film is used for a flexible packaging material (flexible package). Can be suitably used as a laminating adhesive for producing by laminating.
[0061]
That is, in laminating, for example, after diluting a polyisocyanate component and a polyol component with an organic solvent such as ethyl acetate to prepare an adhesive composition of the present invention, this adhesive composition is then mixed with a solvent laminator. Is applied to each film surface, the solvent is stripped, the adhesive surfaces are bonded together, and then cured by curing at room temperature or under heating, or the blending viscosity of the polyisocyanate component and the polyol component is In the case of about 100 to 10000 mPa · s at room temperature to 100 ° C., preferably about 100 to 5000 mPa · s, for example, the polyisocyanate component and the polyol component are blended as they are to prepare the adhesive composition of the present invention. After that, this adhesive composition was applied to each film surface by a solvent-free laminator, Bonding, thereafter, can be carried out by a method of curing by curing at room temperature or under heating. Usually, in the case of a solvent type, the coating amount is about 2.0 to 5.0 g / m after solvent evaporation.²Solvent-free lifting, about 1.0-3.0 g / m²It is preferable that
[0062]
Moreover, as a film to be laminated, for example, plastic films such as polyethylene terephthalate, nylon, polyethylene, polypropylene, polyvinyl chloride, for example, metal foil such as aluminum, metal vapor deposition film, silica vapor deposition film, stainless steel, iron, copper, A metal film such as lead is used. In addition, for example, in the case of a plastic film, the thickness is preferably 5 to 200 μm.
[0063]
Then, the adhesive composition of the present invention is obtained from the composite film laminated in this way, from 0.5 mL / cm per unit area of the composite film.²Concentration of a cyclic compound composed of an amide bond and / or an ester bond (that is, a cyclic compound of at least one of a cyclic amide compound, a cyclic ester compound, and a cyclic amide-ester compound) in the extracted water extracted with The concentration of each cyclic compound) is 0.5 ppb or less in terms of dibutyl phthalate measured by a gas chromatograph-hydrogen ionization detector. If it is 0.5 ppb or less, the elution of the cyclic compound due to the adhesive composition into the content of the composite film is extremely less than that of the conventional ester urethane adhesive.
[0064]
The concentration of the cyclic compound composed of such an amide bond and / or ester bond is determined by, for example, producing a bag from the composite film produced by lamination as described above, and using ion-exchange distilled water as its contents, 0.5 mL / cm per unit area of the composite film²After the bag is sterilized with hot water under pressure, the water content is substantially all amide bonds and / or esters, such as liquid-solid extraction, liquid-liquid extraction, etc. It can be obtained by extracting by a known method capable of recovering a cyclic compound consisting of a bond, and measuring this by using a gas chromatograph method (hydrogen flame ionization detector) as a sample.
[0065]
The quantification may be obtained as a converted value to the dibutyl phthalate concentration using dibutyl phthalate as a standard substance with a flame ionization detector of a gas chromatograph. For example, a cyclic compound comprising an amide bond and / or an ester bond When it can be judged by the presence or absence of a cyclic compound consisting of an amide bond and / or an ester bond that the concentration of is 0.5 ppb or less in terms of dibutyl phthalate, the amide bond and / or The detection limit of the concentration of the cyclic compound composed of an ester bond can be 0.5 ppb in terms of dibutyl phthalate.
[0066]
In the adhesive composition of the present invention, since the concentration of the cyclic compound composed of the amide bond and / or ester bond measured in this way is 0.5 ppb or less, compared to a conventional ester urethane adhesive, The elution of the cyclic compound due to the adhesive composition into the contents of the composite film is extremely small, and therefore the odor inherent to the food or beverage even when the food or beverage is filled. When packaging electronic components such as hard disks, which are problematic even if a small amount of foreign matter is mixed, the performance inherent to the electronic components is not impaired, and It can use suitably as an adhesive agent for manufacturing the composite film for flexible packaging materials which packages this industrial product.
[0067]
Further, the adhesive composition of the present invention is excellent in water resistance due to the inclusion of dimer acid in the polyester polyamide polyol, while the oil resistance is lowered and the ester group concentration is reduced, while the amide acid is reduced. Since the group is contained, the cohesive force is improved, so that the oil resistance can be improved. Therefore, for example, even when used in a composite film for packaging oily foods that require heat sterilization treatment such as retort, the strength of the composite film after heat sterilization treatment is not significantly reduced, and excellent adhesive strength is achieved. Can be held.
[0068]
And since the adhesive composition of this invention expresses the softness | flexibility of the adhesive agent required for manufacture of the composite film for flexible packaging materials satisfactorily, it can prevent the fall of the peeling strength of a composite film.
[0069]
Therefore, the composite film for soft packaging material of the present invention adhered by the adhesive composition of the present invention does not impair the performance originally possessed by the contents, and there is little decrease in strength after heat sterilization treatment. It can be effectively used as a composite film for soft packaging materials with little decrease in peel strength.
[0070]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. In the examples and comparative examples, “parts” and “%” are all based on weight unless otherwise specified.
[0071]
Production Example 1 (Production of polyester polyamide polyol A)
316.9 g of dimer acid and 29.5 g of isophoronediamine (corresponding to 30 mol% of the carboxylic acid group) were added, respectively, and an amidation reaction was performed at 180 to 220 ° C. in a nitrogen stream to obtain polyamide polycarboxylic acid A. The resulting polyamide polycarboxylic acid A had an acid value of 125.5 mgKOH / g.
[0072]
Separately, 367.9 g of isophthalic acid, 404.9 g of 1,6-hexanediol, and 0.1 g of zinc acetate were added, respectively, and an esterification reaction was performed at 180 to 220 ° C. in a nitrogen stream. After distilling a predetermined amount of water, 340.2 g of a separately synthesized polyamide polycarboxylic acid A was added thereto, and an esterification reaction was carried out under a nitrogen stream at 180 to 220 ° C. until the acid value was 1 or less. Got. The resulting polyester polyamide polyol A had an acid value of 0.4 mgKOH / g and a hydroxyl value of 75.7 mgKOH / g.
[0073]
Production Example 2 (Production of polyester polyamide polyol B)
367.9 g of isophthalic acid, 404.9 g of 1,6-hexanediol, and 0.1 g of zinc acetate were added, respectively, and an esterification reaction was performed at 180 to 220 ° C. in a nitrogen stream. After distilling a predetermined amount of water, 316.9 g of dimer acid and 29.5 g of isophoronediamine are added, and an amidation reaction and an esterification reaction are carried out under a nitrogen stream at 180 to 220 ° C. until the acid value becomes 1 or less. Polyol B was obtained. The resulting polyester polyamide polyol B had an acid value of 0.7 mgKOH / g and a hydroxyl value of 75.4 mgKOH / g.
[0074]
Production Example 3 (Production of polyester polyamide polyol C)
367.9 g of isophthalic acid, 404.9 g of 1,6-hexanediol, 29.5 g of isophoronediamine, and 0.1 g of zinc acetate were added, respectively, and an esterification reaction and an amidation reaction were performed at 180 to 220 ° C. in a nitrogen stream. . After distilling a predetermined amount of water, 316.9 g of dimer acid was added, and an amidation reaction and an esterification reaction were carried out at 180 to 220 ° C. under a nitrogen stream until an acid value of 1 or less was obtained, whereby a polyester polyamide polyol C was obtained. The resulting polyester polyamide polyol C had an acid value of 0.9 mgKOH / g and a hydroxyl value of 75.0 mgKOH / g.
[0075]
Production Example 4 (Production of polyester polyol A)
371.5 g of isophthalic acid, 413.2 g of 1,6-hexanediol, and 0.1 g of zinc acetate were added, respectively, and an esterification reaction was performed at 180 to 220 ° C. under a nitrogen stream. After distilling a predetermined amount of water, 320.0 g of dimer acid was added, and an esterification reaction was carried out at 180 to 220 ° C. in a nitrogen stream until the acid value became 1 or less to obtain polyester polyol A. The obtained polyester polyol A had an acid value of 0.5 mgKOH / g and a hydroxyl value of 75.6 mgKOH / g.
[0076]
Production Example 5 (Production of polyol component A)
400 g of polyester polyamide polyol A and 71.1 g of isophorone diisocyanate were added, respectively, and chain elongation reaction was performed at 100 to 110 ° C. in a nitrogen atmosphere to obtain polyurethane polyester polyamide polyol A. After the reaction, polyol component A was obtained by adding ethyl acetate thereto to obtain a solution having a solid content of 50%.
[0077]
Production Example 6 (Production of polyol component B)
400 g of polyester polyamide polyol B and 71.1 g of isophorone diisocyanate were added, respectively, and chain elongation reaction was performed at 100 to 110 ° C. in a nitrogen atmosphere to obtain polyurethane polyester polyamide polyol B. After the reaction, polyol component B was obtained by adding ethyl acetate thereto to obtain a solution having a solid content of 50%.
[0078]
Production Example 7 (Production of polyol component C)
400 g of polyester polyamide polyol C and 71.1 g of isophorone diisocyanate were added, respectively, and chain elongation reaction was performed at 100 to 110 ° C. in a nitrogen atmosphere to obtain polyurethane polyester polyamide polyol C. After the reaction, polyol component C was obtained by adding ethyl acetate to the solution to give a solid content of 50%.
[0079]
Production Example 8 (Production of polyol component D)
400 g of polyester polyol A and 71.1 g of isophorone diisocyanate were added, respectively, and chain elongation reaction was performed at 100 to 110 ° C. in a nitrogen atmosphere to obtain polyurethane polyester polyol A. After the reaction, polyol component D was obtained by adding ethyl acetate thereto to obtain a solution having a solid content of 50%.
[0080]
Production Example 9 (Production of polyol component E)
2,6-Naphthalenedicarboxylic acid dimethyl ester (120.3 g), ethylene glycol (29.0 g), neopentyl glycol (48.7 g), propylene glycol (23.7 g), and titanium tetrabutoxide (0.01 g) were added, respectively, and 180 to 220 ° C. under a nitrogen stream. The transesterification reaction was carried out. After distilling a predetermined amount of methanol, add 281.9 g of dimer acid and 51.0 g of isophoronediamine, and perform an amidation reaction and an esterification reaction at 180-220 ° C. until the acid value is 1 or less. After distillation, the inside of the system was gradually depressurized and subjected to polycondensation at 13.3 Pa or less and 220 ° C. for 4 hours to obtain a high molecular weight polyester polyamide polyol A. This whole amount was dissolved in ethyl acetate to obtain a polyol component E having a solid content of 50%.
[0081]
Production Example 10 (Production of polyol component F)
Add 120.3 g of 2,6-naphthalenedicarboxylic acid dimethyl ester, 29.0 g of ethylene glycol, 48.7 g of neopentyl glycol, 23.7 g of propylene glycol, 51.0 g of isophoronediamine, 0.01 g of titanium tetrabutoxide, and add nitrogen. The transesterification was carried out at 180 to 220 ° C. under an air stream. After distilling a predetermined amount of methanol, 281.9 g of dimer acid was added, an amidation reaction and an esterification reaction were performed at 180 to 220 ° C. until the acid value was 1 or less, and after distilling a predetermined amount of water, The pressure was gradually reduced and polycondensation was carried out at 13.3 Pa or less and 220 ° C. for 4 hours to obtain a high molecular weight polyester polyamide polyol B. This whole amount was dissolved in ethyl acetate to obtain a polyol component F having a solid content of 50%.
[0082]
  Production Example 11 (Production of polyol component G)
  2,6-Naphthalenedicarboxylic acid dimethyl ester 128.0 g, ethylene glycol 30.3 g, neopentyl glycol 50.8 g, propylene glycol 49.5 g and titanium tetrabutoxide 0.01 g were added, respectively, and 180-220 ° C. under a nitrogen stream. The transesterification reaction was carried out. After distilling a predetermined amount of methanol, add 300.0 g of dimer acid, and carry out an esterification reaction at 180-220 ° C. until the acid value is 1 or less. After distilling a predetermined amount of water, the system is gradually depressurized. And a polycondensation is carried out for 4 hours at 13.3 Pa or less and 220 ° C.LupoReal C was obtained. This whole amount was dissolved in ethyl acetate to obtain a polyol component G having a solid content of 50%.
[0083]
Production Example 12 (Production of polyol component H)
400 g of polyester polyamide polyol B, 4.4 g of dimethylol butanoic acid, 54.6 g of dicyclohexylmethane-4,4′-diisocyanate were added, respectively, and chain elongation reaction was carried out at 110 to 120 ° C. in a nitrogen atmosphere to obtain polyurethane polyester polyamide polyol D. Obtained. After the reaction, ethyl acetate was added thereto to obtain a polyol component H having a solid content of 50%.
[0084]
Production Example 13 (Production of polyol component I)
Polyester polyamide polyol B was thin-film distilled to add 71.1 g of isophorone diisocyanate to 400 g of polyester polyamide polyol B ′ containing 1,6-hexanediol monomer of 0.1% by weight or less, and chained at 100 to 110 ° C. in a nitrogen atmosphere. Elongation reaction was performed to obtain polyurethane polyester polyamide polyol E. After the reaction, polyol component I was obtained by adding ethyl acetate thereto to obtain a solution having a solid content of 50%.
[0085]
Production Example 14 (Production of polyisocyanate component A)
50 g of Takenate A-10 (trimethylolpropane adduct of xylylene diisocyanate, manufactured by Mitsui Takeda Chemical Co., Ltd.) and 50 g of Takenate A-40 (trimethylolpropane adduct of isophorone diisocyanate, manufactured by Mitsui Takeda Chemical Co., Ltd.) Polyisocyanate component A was obtained by uniformly mixing at 50 ° C. in a nitrogen atmosphere.
[0086]
Preparation and evaluation of examples and comparative examples
Table 1 shows the polyol components A to I, the isocyanate component A, and the silane coupling agent (γ-glycidoxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.) obtained as described above. The adhesive compositions of Examples 1 to 9 and Comparative Examples 1 and 2 were prepared. Next, using the obtained adhesive compositions of each Example and each Comparative Example, composite films were prepared by the method described later, and then an elution test and a retort test were performed on each composite film. The results are shown in Table 2.
[0087]
Production of composite film
A composite film comprising four layers of polyethylene terephthalate film (thickness 12 μm) / nylon film (thickness 15 μm) / aluminum foil (9 μm) / unstretched polypropylene film (thickness 70 μm: single-sided corona treatment) was produced by the method described below.
[0088]
That is, the adhesive composition of each example and each comparative example shown in Table 1 was first applied to a polyethylene terephthalate film by a dry laminator, and the solid content weight of the adhesive composition per unit area was 2.5 g / m.²Then, the solvent was stripped and the coated surface was bonded to a nylon film. Next, an adhesive was applied to the nylon film surface of the two-layer composite film in the same manner as described above to evaporate the solvent, and then the coated surface was bonded to an aluminum foil. Next, in the same manner as described above, an adhesive was applied to the aluminum surface of the three-layer composite film to volatilize the solvent, and then the coated surface was bonded to the corona-treated surface of the unstretched polypropylene film. Then, these bonded films were cured under conditions of 50 ° C. and 3 days to cure the adhesive composition.
[0089]
Dissolution test
A bag is produced from the composite film produced as described above, and ion-exchanged distilled water is used as the content, 0.5 mL / cm per unit area of the bag inner surface.²It was filled with the quantity which becomes. This bag is 19.6 × 10 6 at 120 ° C. for 30 minutes.⁴After performing hot water sterilization under pressure of Pa, extract the content water with a solid phase modified with octadecyl group, and dissolve the extract in 1 / 100th volume of methanol of the original water sample As a measurement, gas chromatography (hydrogen flame ionization detector) was used to measure the presence or absence of a cyclic amide compound, a cyclic ester compound and a cyclic amide-ester compound. When an eluate was observed, the structure was identified with a gas chromatograph mass spectrometer. The detection limit of this gas chromatograph (hydrogen flame ionization detector) in a methanol solution of dibutyl phthalate is 50 ppb, and each of the cyclic amide compound, cyclic ester compound and cyclic amide-ester compound in the extraction water in this elution test is The detection limit when converted to a concentration was 0.5 ppb.
[0090]
Retort test
A bag was produced from the composite film produced as described above, and filled with a mixture of vinegar, ketchup, and salad oil at a 1/1/1 weight as the contents. This bag is 19.6 × 10 6 at 120 ° C. for 30 minutes.⁴After performing hot water sterilization under Pa pressure, the peeled state between the nylon film and the aluminum foil was observed. Subsequently, the content was taken out and the peel strength between the aluminum foil and the unstretched polypropylene film was measured. The peel strength was measured before and after retort sterilization.
[0091]
[Table 1]

[0092]
[Table 2]

【The invention's effect】
According to the adhesive composition of the present invention, the elution of the cyclic compound resulting from the adhesive composition into the contents from the composite film adhered by the adhesive composition is a conventional ester-based urethane adhesive. Compared to the above, even if foods and beverages are filled, it does not impair the original odor of the foods and beverages. Even when packaging electronic parts such as hard disks, the composite film for flexible packaging materials that wraps various industrial products including these without compromising the performance inherent to the electronic parts. It can be suitably used as an adhesive.
[0093]
In addition, since the adhesive composition of the present invention is excellent in oil resistance, the strength of the composite film after the heat sterilization treatment is used even when it is used for a composite film for packaging oily foods that require heat sterilization treatment such as retort. It is possible to maintain excellent adhesive strength without significantly lowering.
[0094]
And since the adhesive composition of this invention expresses the softness | flexibility of the adhesive agent required for manufacture of the composite film for flexible packaging materials satisfactorily, it can prevent the fall of the peeling strength of a composite film.
[0095]
Therefore, the composite film for soft packaging material of the present invention adhered by the adhesive composition of the present invention does not impair the performance originally possessed by the contents, and there is little decrease in strength after heat sterilization treatment. It can be effectively used as a composite film for soft packaging materials with little decrease in peel strength.

Claims (5)

Including a polyisocyanate component and a polyol component;
The polyol component consists of a polyester polyamide polyols and / or polyurethane polyester polyamide polyols including a polyester unit and a polyamide unit,
The polyester unit is
Ester bond obtained by reaction of phthalic acid and / or its alkyl ester with 1,6-hexanediol, ester bond obtained by reaction of naphthalene dicarboxylic acid and / or its alkyl ester with glycol, and dimer acid and glycol Including at least one ester bond selected from the group consisting of ester bonds obtained by reaction with
The amide bond of the polyamide unit is an amide bond obtained by a reaction between a dimer acid and a polyamine,
The concentration of the cyclic compound consisting of an amide bond and / or an ester bond in the extracted water extracted from the composite film adhered by the adhesive composition with 0.5 mL / cm ² of water per unit area of the composite film, An adhesive composition characterized in that it is 0.5 ppb or less in terms of dibutyl phthalate measured with a gas chromatograph-hydrogen flame ionization detector. 2. The adhesive composition according to claim 1, wherein 10 to 90 mol% of the carboxyl group of the dimer acid forming the amide bond is reacted with the amino group of the polyamine. Furthermore, a silane coupling agent is contained, The adhesive composition of Claim 1 or 2 characterized by the above-mentioned. It is used for manufacture of the composite film for flexible packaging materials, The adhesive composition in any one of Claims 1-3 characterized by the above-mentioned. The composite film for soft packaging materials adhere | attached with the adhesive composition of Claim 4 .