JP5563843B2 - Two-component curable solventless adhesive - Google Patents

Description

  The present invention relates to a two-component curable solventless adhesive, and more particularly to a two-component curable solventless adhesive suitable as a laminating adhesive.

  Composite films in which various films are bonded with a laminating adhesive are widely used in the field of packaging materials. In particular, a composite film in which a plastic film and a metal foil are adhered with a laminating adhesive is excellent in light-shielding properties, gas and liquid barrier properties, and is widely used as a food packaging material subjected to high-temperature sterilization treatment. Yes.

  As a laminating adhesive used for bonding a composite film, a two-component curable adhesive composed of a polyisocyanate component and a polyol component is widely known.

  In recent years, development of a two-component curable solventless adhesive that does not contain an organic solvent has been studied from the viewpoint of reducing the environmental burden and improving the working environment.

  For example, in the main agent (polyol component), 30% or more of all terminal hydroxyl groups are secondary or tertiary terminal hydroxyl groups, and a polyol containing an acid group is contained, and the curing agent (polyisocyanate component) is an aromatic fat. An isocyanate group-terminated urethane prepolymer obtained by reaction of an aromatic polyisocyanate and a polyol and having an average functional group number of 1.5 to 2.5, an aliphatic polyisocyanate and / or a modified product thereof, It has been proposed to prepare a two-component curable solventless adhesive from a polyol component and a polyisocyanate component (see, for example, Patent Document 1).

  Specifically, in the examples, a polyester diol whose molecular terminal was acid-modified with trimellitic anhydride was used as the polyol component, and the polyisocyanate component was obtained by reaction of polyester diol and xylylene diisocyanate. A mixture of an isocyanate group-terminated urethane prepolymer and a trimer of hexamethylene diisocyanate is used.

JP 2006-213801 A

  The composite film stuck with the two-component curable solventless adhesive described in Patent Document 1 has excellent appearance and adhesion even after high-temperature sterilization treatment and storage at high temperature for a long period (50 ° C, 2 weeks) Maintains strength.

  However, in recent years, a two-component curable solventless adhesive that can sufficiently maintain the above performance even under severer storage conditions (60 ° C., 4 weeks) after high-temperature sterilization has been desired. There is a demand for improved pot life and acid resistance.

  The object of the present invention is to maintain the appearance and adhesive strength of the composite film even under severe storage conditions after high-temperature sterilization treatment. An object of the present invention is to provide an excellent two-component curable solventless adhesive.

  In order to achieve the above object, the two-component curable solventless adhesive of the present invention includes a polyisocyanate component and a polyol component, and the polyisocyanate component includes a diisocyanate containing an araliphatic diisocyanate, a diol containing a macrodiol, and The polyol component contains a diisocyanate-terminated prepolymer obtained by reacting with diol, the average functional group number exceeds 2, and the crosslinkability having a diol containing a macrodiol and three or more secondary or tertiary hydroxyl groups A polyol, and / or the diol and the crosslinkable polyol contain a urethane-modified polyol that is urethane-modified, and the acid value exceeds 20 and is partially reduced to 40 or less. It is characterized by terminal acid modification.

  In the two-component curable solventless adhesive of the present invention, the number average molecular weight of the crosslinkable polyol is preferably 100 to 2,000.

  In the two-part curable solventless adhesive of the present invention, the crosslinkable polyol is a trifunctional polypropylene polyol, and the crosslinkable polyol is contained in an amount of 10 to 20% by mass with respect to the polyol component. Is preferred.

  In the two-component curable solventless adhesive of the present invention, the araliphatic diisocyanate is xylylene diisocyanate, and the diisocyanate-terminated prepolymer is contained in an amount of 10 to 50% by mass with respect to the polyisocyanate component. Is preferred.

  In the two-component curable solventless adhesive of the present invention, the polyisocyanate component preferably further contains at least one selected from aliphatic diisocyanate, alicyclic diisocyanate, and derivatives thereof. It is.

  In the two-component curable solventless adhesive of the present invention, it is preferable that the aliphatic diisocyanate is hexamethylene diisocyanate and the alicyclic diisocyanate is isophorone diisocyanate.

  The composite film stuck by the two-component curable solventless adhesive of the present invention can maintain excellent appearance and adhesive strength even under severe storage conditions after high-temperature sterilization treatment. It has a good pot life and can have excellent acid resistance.

  The two-part curable solventless adhesive of the present invention does not contain an organic solvent and water, and each of the polyisocyanate component and the polyol component is prepared and blended at the time of use. Prepared as an adhesive.

  Examples of the polyisocyanate include a polyisocyanate monomer, a polyisocyanate derivative, and a polyisocyanate-terminated prepolymer.

  Examples of the polyisocyanate monomer include diisocyanates such as aromatic diisocyanate, araliphatic diisocyanate, alicyclic diisocyanate, and aliphatic diisocyanate.

  Examples of the aromatic diisocyanate include m- or p-phenylene diisocyanate or a mixture thereof, 2,4- or 2,6-tolylene diisocyanate or a mixture thereof (TDI), 4,4'-, 2,4'- or 2,2'-diphenylmethane diisocyanate or mixtures thereof (MDI), 4,4'-toluidine diisocyanate (TODI), 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate (NDI) Etc.

  Examples of the araliphatic diisocyanate include 1,3- or 1,4-xylylene diisocyanate or a mixture thereof (XDI), 1,3- or 1,4-tetramethylxylylene diisocyanate or a mixture thereof (TMXDI), ω , Ω′-diisocyanate-1,4-diethylbenzene and the like.

  Examples of the alicyclic diisocyanate include 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (isophorone diisocyanate; IPDI ), 4,4'-, 2,4'- or 2,2'-dicyclohexylmethane diisocyanate or mixtures thereof (hydrogenated MDI), methyl-2,4-cyclohexanediisocyanate, methyl-2,6-cyclohexanediisocyanate, 1 , 3- or 1,4-bis (isocyanatomethyl) cyclohexane or a mixture thereof (hydrogenated XDI).

  Examples of the aliphatic diisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), 1,2-, 2,3- or 1,3-butylene diisocyanate, 2,4,4- Alternatively, 2,2,4-trimethylhexamethylene diisocyanate and the like can be mentioned.

  Examples of the polyisocyanate derivative include a polyisocyanate monomer multimer (eg, dimer, trimer, pentamer, heptamer, etc.), allophanate-modified product (eg, polyisocyanate monomer, Allophanate-modified products produced by reaction with alcohols), biuret-modified products (for example, biuret-modified products produced by reaction of polyisocyanate monomers with water and amines), urea-modified products (for example, poly Modified urea compound produced by reaction of isocyanate monomer and diamine), oxadiazine trione (for example, oxadiazine trione produced by reaction of polyisocyanate monomer and carbon dioxide), modified carbodiimide ( Modified carbodiimide produced by decarboxylation condensation reaction of polyisocyanate monomer ), And the like.

  The diisocyanate-terminated prepolymer is a urethane prepolymer having two isocyanate groups at the molecular ends, and is a diisocyanate (a diisocyanate selected from a polyisocyanate monomer, a polyisocyanate derivative and a diisocyanate-terminated prepolymer, preferably a polyisocyanate single polymer). A diisocyanate selected from a monomer and a polyisocyanate derivative) and a diol (to be described later), a ratio in which the equivalent ratio of diisocyanate to a hydroxyl group of the diol (to be described later) (NCO / OH) is greater than 1, preferably 2 to It can be obtained by urethanization reaction at a ratio of 100.

  The urethanization reaction can be based on a known method, and preferably unreacted diisocyanate is removed by a known removal method such as a thin film distillation method.

  The isocyanate group equivalent of a diisocyanate terminal prepolymer is 200-2000, for example, Preferably, it is 300-1000. Moreover, content of unreacted diisocyanate is 15 mass% or less, for example, Preferably, it is 5 mass% or less, More preferably, it is 1 mass% or less.

  In addition, an isocyanate group equivalent is synonymous with an amine equivalent, and can be calculated | required by A method or B method of JISK1603-1. The content of unreacted diisocyanate can be determined, for example, by HPLC measurement.

  As the polyisocyanate component, one type or two or more types are selected from a polyisocyanate monomer, a polyisocyanate derivative, and a diisocyanate-terminated prepolymer. The polyisocyanate component includes a diisocyanate containing an araliphatic diisocyanate as an essential component. And a diisocyanate-terminated prepolymer obtained by reacting a diol (described later) containing a macrodiol (described later).

  By including such a diisocyanate-terminated prepolymer, an increase in viscosity of the diisocyanate-terminated prepolymer can be suppressed, and an increase in coating temperature can be suppressed during the production of the composite film. As a result, it is possible to prevent poor workability due to a sudden increase in viscosity.

  In the diisocyanate-terminated prepolymer contained as an essential component, the diisocyanate contains an araliphatic diisocyanate as an essential raw material component. Preferably, XDI is contained. The diol (described later) contains macrodiol (described later) as an essential raw material component. Preferably, a polyester diol (described later) is contained, and more preferably a macro diol (polyester diol) having the same composition as the macro diol (polyester diol) contained in the polyol component is contained.

  If the diisocyanate-terminated prepolymer contained as an essential component contains araliphatic diisocyanate and macrodiol as essential raw material components, other diisocyanates and diols (described later) can also be contained as optional raw material components. .

  For example, as the diisocyanate, a polyisocyanate derivative, preferably an aliphatic diisocyanate derivative can be used in combination with an araliphatic diisocyanate. Moreover, as diol (after-mentioned), low molecular weight diol (after-mentioned), Preferably aliphatic diol (after-mentioned) can be used together with macrodiol (after-mentioned).

  Moreover, the diisocyanate terminal prepolymer contained as an essential component is 3-80 mass% with respect to a polyisocyanate component, Preferably, it is 5-70 mass%, More preferably, 10-50 mass% is contained. .

  Further, the polyisocyanate component includes, as an optional component, at least one selected from aliphatic diisocyanates, alicyclic diisocyanates and derivatives thereof, preferably HDI derivatives and / or IPDI derivatives, more preferably HDI. Allophanate modifications and / or trimers of IPDI can be included. At least one selected from aliphatic diisocyanate, alicyclic diisocyanate and derivatives thereof is, for example, 20 to 95% by mass, preferably 30 to 95% by mass, more preferably 50%, based on the polyisocyanate component. It is contained at ~ 90% by mass. Moreover, at least 1 sort (s) selected from aliphatic diisocyanate, alicyclic diisocyanate, and those derivatives is 20-2000 mass parts with respect to 100 mass parts of diisocyanate terminal prepolymers, Preferably, it is 60-900 mass parts It is blended at a ratio of

  The polyisocyanate component contains, as an essential component, a diisocyanate-terminated prepolymer obtained by reacting a diisocyanate containing an araliphatic diisocyanate and a diol (described later) containing a macrodiol (described later), and as an optional component. , At least one selected from aliphatic diisocyanates, alicyclic diisocyanates and derivatives thereof, and, if necessary, other polyisocyanate monomers, polyisocyanate derivatives and diisocyanate-terminated prepolymers. Can be prepared. Specifically, the polyisocyanate component can be prepared by stirring and mixing the above-described components, for example, in an inert gas atmosphere.

  The polyisocyanate component preferably comprises a diisocyanate-terminated prepolymer obtained by reacting a diisocyanate containing an araliphatic diisocyanate with a diol (described later) containing a macrodiol (described later), an aliphatic diisocyanate and / or a derivative thereof. Blend. By doing so, it is possible to improve the content resistance after the heat sterilization treatment. Further, in combination with the reactivity with the polyol component, an appropriate pot life at the time of blending the polyisocyanate component and the polyol component can be obtained, and good workability can be ensured.

  The polyisocyanate component is preferably prepared so that the content of the polyisocyanate monomer is, for example, 15% by mass or less, preferably 1% by mass or less. In order to make the content of the polyisocyanate monomer 1% by weight or less, for example, the blending ratio of each component is adjusted, or the polyisocyanate monomer is removed by a known removal method such as a thin film distillation method. .

  And the isocyanate group equivalent of the polyisocyanate component prepared in this way is 150-750, for example, Preferably, it is 200-500.

  In the present invention, the average number of functional groups of the polyol component exceeds 2. That is, the polyol component contains a diol containing a macrodiol and a crosslinkable polyol having three or more hydroxyl groups, and / or a urethane in which the above diol and the above crosslinkable polyol are urethane-modified. It contains a modified polyol, and thus the average number of functional groups of the polyol component exceeds 2, preferably 2.05 or more, more preferably 2.1 or more, usually 5.0 or less, preferably 4 0.0 or less.

  The diol is a polyol having two hydroxyl groups, and examples thereof include a low molecular weight diol and a macrodiol.

  The low molecular weight diol is a bifunctional polyol having two hydroxyl groups and having a number average molecular weight, for example, less than 400, preferably less than 300, usually 60 or more, such as aliphatic diol, alicyclic diol, And aromatic diols.

  Examples of the aliphatic diol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, 1,3-butanediol, 1,2-butanediol, 2 -Methyl-1,3-propanediol, 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,7-heptanediol, 1,5- Heptanediol, 2,4-diethyl-1,5-pentanediol, 2,2,4-trimethylpentane-1,3-diol, 1,8-octanediol, 1,9-nonanediol, 3,3'- Dimethylol heptane, 1,10-decanediol, 1,11-undeca Diol, 1,12-undecane diol, 12-hydroxy stearyl alcohol, and hydrogenated dimer diols.

  Examples of the alicyclic diol include hydrogenated bisphenol A, hydrogenated xylylene diol, cyclohexane diol, and cyclohexane dimethanol.

  Examples of the aromatic diol include bisphenol A, bishydroxyethyl terephthalate, catechol, resorcin, hydroquinone, 1,3- or 1,4-xylylenediol.

  As the low molecular weight diol, an aliphatic diol is preferable. The low molecular weight diol is contained, for example, in an amount of 20% by mass or less, preferably 10% by mass or less, and more preferably 5% by mass or less with respect to the diol.

  The macrodiol is a bifunctional polyol having two hydroxyl groups and having a number average molecular weight of, for example, 400 or more, preferably 500 or more, and usually 2000 or less. For example, polyester diol, polycaprolactone diol, polycarbonate diol, Examples include polyether diol.

  The polyester diol can be obtained by a condensation reaction between a dibasic acid and the above-described low molecular weight diol (dihydric alcohol) or a transesterification reaction between the dibasic acid alkyl ester and the above low molecular weight diol (dihydric alcohol). it can.

  Examples of the dibasic acid include aliphatic dicarboxylic acids such as succinic acid, glutaric acid, adipic acid, pimelic acid, corkic acid, azelaic acid, sebacic acid, dodecanedioic acid, and dimer acid, such as hexahydrophthalic acid. And alicyclic divalent carboxylic acids such as aromatic divalent carboxylic acids such as phthalic acid, isophthalic acid and terephthalic acid.

  Moreover, as an alkyl ester of a dibasic acid, the above-mentioned C1-4 alkyl ester of a dibasic acid is mentioned, for example.

  In the polyester diol, the dibasic acid and the alkyl ester thereof preferably include aliphatic divalent carboxylic acids, aromatic divalent carboxylic acids and alkyl esters thereof, more preferably aliphatic divalent carboxylic acids and aromatic esters. The combined use of a group 2 divalent carboxylic acid is exemplified. As the low molecular weight diol, an aliphatic diol is preferable.

  The condensation reaction or transesterification reaction is not particularly limited, and can be based on a known method. For example, each component is charged and reacted at 150 to 240 ° C. for 7 to 50 hours in an inert gas atmosphere. In addition, a known catalyst (for example, a titanium catalyst, a zinc catalyst, etc.) can be added to this reaction.

  The hydroxyl group equivalent of polyester diol is 150-1000, for example, Preferably, it is 200-750, and a number average molecular weight is 300-2000, for example, Preferably, it is 400-1500. The hydroxyl equivalent can be calculated from the hydroxyl value obtained from the acetylation method or the phthalation method according to the method A or B of JIS K1557-1. The number average molecular weight can be determined from the hydroxyl group equivalent and the number of functional groups.

  Examples of the polycaprolactone diol include polycaprolactone diol obtained by ring-opening polymerization of ε-caprolactone.

  Examples of the polycarbonate diol include polycarbonate diol obtained by a condensation reaction of the above-described low molecular weight diol (dihydric alcohol) with dimethyl carbonate, diethyl carbonate and the like.

  As the polyether diol, for example, polyethylene glycol, polypropylene glycol and / or obtained by addition reaction of alkylene oxide such as ethylene oxide and / or propylene oxide using the above-described low molecular weight diol (dihydric alcohol) as an initiator. Or polyoxy C2-3 alkylene (ethylene and / or propylene) glycols such as polyethylene polypropylene glycol (random or block copolymers).

  Examples of the polyether diol include polytetramethylene ether glycol (polyoxybutylene glycol) obtained by, for example, ring-opening polymerization of tetrahydrofuran.

  These macrodiols can be used alone or in combination of two or more.

  As the macrodiol, polyester diol is preferable.

  One or more diols are selected from low molecular weight diols and macrodiols, and the diol contains macrodiol as an essential component.

  The macrodiol is contained in an amount of, for example, 30% by mass or more, preferably 40% by mass or more, and more preferably 50% by mass or more with respect to the diol.

  In the present invention, the crosslinkable polyol has three or more secondary or tertiary hydroxyl groups and has a number average molecular weight, for example, 50 to 3000, preferably 100 to 2000, more preferably 110 to 500 trifunctional. As mentioned above, Preferably, it is a 3-6 functional polyol.

  As such a crosslinkable polyol, for example, a crosslinkable polyol having three or more hydroxyl groups and all the hydroxyl groups being secondary or tertiary hydroxyl groups can be mentioned. Polypropylene polyol, cyclohexanetriol, inositol and the like. Preferably, a trifunctional or higher functional polypropylene polyol is used.

  A tri- or more functional polypropylene polyol is a polypropylene polyol having three or more hydroxyl groups and all of the hydroxyl groups are secondary or tertiary hydroxyl groups, for example, a polyhydric alcohol having three or more hydroxyl groups. It can be obtained by addition reaction of propylene oxide as an initiator.

  Examples of the polyhydric alcohol having three or more hydroxyl groups include glycerin, 2-methyl-2-hydroxymethyl-1,3-propanediol, 2,4-dihydroxy-3-hydroxymethylpentane, 1,2,6- Trivalent alcohols such as hexanetriol, trimethylolpropane, 2,2-bis (hydroxymethyl) -3-butanol and other aliphatic triols (8 to 24 carbon atoms), for example, tetramethylolmethane (pentaerythritol), di Tetravalent alcohols such as glycerin, for example, pentavalent alcohols such as xylitol, for example, hexavalent alcohols such as sorbitol, mannitol, allitol, iditol, dulcitol, altritol, inositol, dipentaerythritol, for example, 7-valent alcohols such as perseitol. Call, for example, 8 monohydric alcohol and sucrose.

  As such a tri- or more functional polypropylene polyol, a polypropylene polyol obtained by an addition reaction of propylene oxide using a trihydric alcohol as an initiator (that is, a trifunctional polypropylene polyol) is preferable.

  If a trifunctional polypropylene polyol is used, an increase in the viscosity of the compounded liquid due to a crosslinking reaction can be suppressed, and an appropriate pot life can be obtained.

  The crosslinkable polyol is not limited to the above as long as it has three or more secondary or tertiary hydroxyl groups. For example, it has three or more secondary or tertiary hydroxyl groups, Also included are crosslinkable polyols having one or more primary hydroxyl groups.

  Examples of such a crosslinkable polyol include polypropylene polyethylene polyol obtained by addition reaction of propylene oxide and ethylene oxide using a polyhydric alcohol having three or more hydroxyl groups as an initiator.

  These crosslinkable polyols can be used alone or in combination of two or more.

  As the crosslinkable polyol, preferably, a crosslinkable polyol having three or more hydroxyl groups, all of which are secondary or tertiary hydroxyl groups, can be used alone.

  The urethane-modified polyol includes the above-described diol and the above-described crosslinkable polyol, the above-described polyisocyanate monomer and / or polyisocyanate derivative, the above-described diol and the polyisocyanate monomer with respect to the hydroxyl group of the above-described crosslinkable polyol, and / or Alternatively, the polyisocyanate derivative can be obtained by urethanating the isocyanate group at an equivalent ratio (NCO / OH) of less than 1.

  In the urethane-modified polyol, the polyisocyanate monomer and / or the polyisocyanate derivative is preferably an araliphatic diisocyanate. Moreover, the hydroxyl equivalent of urethane-modified polyol is 150-1000, for example, Preferably, it is 200-750, and a number average molecular weight is 300-2000, for example, Preferably, it is 400-1500.

  The polyol component contains the above-described diol and the above-described crosslinkable polyol and / or contains the above-described urethane-modified polyol.

  When the diol and the crosslinkable polyol are contained, the diol is, for example, 20 to 95% by mass, preferably 60 to 90% by mass, and more preferably 80 to 90% by mass with respect to the polyol component. % Content. Moreover, a crosslinkable polyol is 5-50 mass% with respect to a polyol component, for example, Preferably, 10-20 mass%, More preferably, 12-20 mass% is contained. Moreover, a crosslinkable polyol is mix | blended in the ratio of 5-50 mass parts with respect to 100 mass parts of diol, Preferably, 10-30 mass parts.

  The urethane-modified polyol is contained, for example, 10% by mass or more, preferably 30% by mass or more, and more preferably 50% by mass or more based on the polyol component.

  And a polyol component mix | blends each above-described component, ie, above-mentioned diol, above-mentioned crosslinkable polyol, and / or above-mentioned urethane modified polyol, Then, each component contained in a polyol component (above-mentioned above) The terminal hydroxyl group of the diol and the above-described crosslinkable polyol and / or the above urethane-modified polyol) is prepared by partially terminal acid modification so that the acid value exceeds 20 and is 40 or less. be able to.

  By modifying the polyol component with a terminal acid, it is possible to improve the adhesive strength, and to prevent deterioration of the content resistance after the heat sterilization treatment.

  In blending each component, a macrodiol and a crosslinkable polyol and / or a urethane-modified polyol are blended as essential components, and a low molecular weight diol is blended as an optional component.

  The urethane-modified polyol is, for example, blended with a diol and a crosslinkable polyol, and together with the above polyisocyanate monomer and / or polyisocyanate derivative, to form the diol and the crosslinkable polyol with the above polyisocyanate. Monomers and / or polyisocyanate derivatives can be blended by urethanization reaction.

  In this case, depending on the blending ratio of the polyisocyanate monomer and / or polyisocyanate derivative to the diol and the crosslinkable polyol, the blending ratio of the diol and the crosslinkable polyol and the urethane-modified polyol in the polyol component is appropriately determined. The

  In order to modify the polyol component with a terminal acid, for example, an acid anhydride is added to a terminal hydroxyl group of each component (the above-described diol and the above-described crosslinkable polyol and / or the above-described urethane-modified polyol) contained in the polyol component. React.

  Examples of the anhydride include trimellitic anhydride, phthalic anhydride, maleic anhydride, pyromellitic anhydride, and the like. Preferably, trimellitic anhydride is used.

  In order to modify the terminal hydroxyl group with an acid anhydride, for example, a polyol component, an acid anhydride, an acid value (mgKOH / g) of the polyol component is more than 20, and a ratio of 40 or less, preferably more than 25. , At a ratio of 40 or less, for example, reacted at 100 to 200 ° C. Thereby, a carboxyl group is partially introduced into the molecular terminal of each component contained in the polyol component.

  If the acid value is at least the above lower limit, the adhesive strength can be improved. On the other hand, when the acid value is set to the above lower limit or less, a rapid increase in viscosity can be suppressed when the polyisocyanate component and the polyol component are blended.

  In addition, an acid value (mgKOH / g) can be calculated | required based on JISK1557-5. The carboxyl group equivalent can be calculated from the acid value.

  Thus, the hydroxyl value (mgKOH / g) of the polyol component prepared is 150-2000, for example, Preferably, it is 200-1500.

  Moreover, in the two-component curable solventless adhesive of the present invention, for example, phosphorus oxyacid or a derivative thereof or a silane coupling agent is added to one or both of the polyisocyanate component and the polyol component as necessary. Can be blended.

  In the oxygen acid of phosphorus or its derivative, examples of the oxygen acid of phosphorus include phosphoric acids such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, hypophosphoric acid, such as metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid. Examples thereof include condensed phosphoric acids such as acid and ultraphosphoric acid.

  Examples of phosphorus oxyacid derivatives include, for example, phosphates such as sodium and potassium or condensed phosphates such as monomethyl orthophosphate, monoethyl orthophosphate, monopropyl orthophosphate, monobutyl orthophosphate, monophosphate orthophosphate. Monoesters such as 2-ethylhexyl, monophenyl orthophosphate, monomethyl phosphite, monoethyl phosphite, monopropyl phosphite, monobutyl phosphite, mono-2-ethylhexyl phosphite, monophenyl phosphite, For example, di-2-ethylhexyl orthophosphate, diphenyl orthophosphate, trimethyl orthophosphate, triethyl orthophosphate, tripropyl orthophosphate, tributyl orthophosphate, tri-2-ethylhexyl orthophosphate, triphenyl orthophosphate, diphosphorous phosphite Chill, diethyl phosphite, dipropyl phosphite, dibutyl phosphite, di-2-ethylhexyl phosphite, diphenyl phosphite, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, phosphorous acid Examples thereof include di- and triesters such as tributyl, tri-2-ethylhexyl phosphite and triphenyl phosphite, and mono-, di- and triesters obtained from condensed phosphoric acid and alcohols.

  As the oxygen acid of phosphorus or a derivative thereof, phosphoric acids are preferable, and orthophosphoric acid (phosphoric acid) is more preferable.

  As the oxygen acid of phosphorus or its derivative, the above-mentioned various oxygen acids of phosphorus or their derivatives can be used alone or in combination of two or more kinds. Further, the oxygen acid of phosphorus or its derivative is blended in an amount of 0.001 to 3 parts by mass, preferably 0.01 to 2.5 parts by mass with respect to 100 parts by mass in total of the polyisocyanate component and the polyol component.

The silane coupling agent is, for example, structural formula R—Si≡ (X) ₃ or R—Si≡ (R ′) (X) ₂ (wherein R is a vinyl group, an epoxy group, an amino group, an imino group, An organic group having an isocyanate group or a mercapto group, R ′ represents a lower alkyl group having 1 to 4 carbon atoms, and X represents a methoxy group, an ethoxy group, or a chloro atom.

  Specific examples of the silane coupling agent include chlorosilanes such as vinyltrichlorosilane, such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and β- (3,4-epoxy. Epoxy silanes such as cyclohexyl) ethyltrimethoxysilane, di (γ-glycidoxypropyl) dimethoxysilane, such as N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, Aminosilanes such as N-β- (aminoethyl) -γ-propylmethyldimethoxysilane, n- (dimethoxymethylsilylpropyl) ethylenediamine, n- (triethoxysilylpropyl) ethylenediamine, N-phenyl-γ-aminopropyltrimethoxysilane For example, bi Vinylsilane such as Le triethoxysilane, for example, .gamma.-isocyanatopropyltrimethoxysilane, such as isocyanatosilanes such as .gamma.-isocyanatopropyltriethoxysilane and the like.

  As a silane coupling agent, Preferably, an epoxy silane and aminosilane are mentioned, More preferably, combined use of an epoxy silane and aminosilane is mentioned.

  As the silane coupling agent, the various silane coupling agents described above can be used singly or in combination. Moreover, a silane coupling agent is 0.001-10 mass parts with respect to a total of 100 mass parts of a polyisocyanate component and a polyol component, Preferably, 0.01-5 mass parts is mix | blended.

  Furthermore, for one or both of the polyisocyanate component and the polyol component, for example, an epoxy resin, a catalyst, a coating property improving agent, a leveling agent, an antifoaming agent, an antioxidant, or an ultraviolet absorber may be used. Such additives as stabilizers, plasticizers, surfactants, pigments, fillers, organic or inorganic fine particles, antifungal agents and the like can be appropriately blended. The compounding amount of the additive is appropriately determined depending on the purpose and application.

  The two-component curable solventless adhesive according to the present invention is prepared by blending a polyisocyanate component and a polyol component to prepare an adhesive and applying it to an adherend.

  The blending ratio of the polyisocyanate component and the polyol component is, for example, 0.5 to 5, preferably 0.6 to 3 as the equivalent ratio (NCO / OH) of the isocyanate group of the polyisocyanate component to the hydroxyl group of the polyol component. It is the ratio which becomes.

  The two-component curable solventless adhesive of the present invention is formulated as described above, so that the viscosity after 40 minutes after uniformly mixing the polyisocyanate component and the polyol component is 12000 mPa · s or less at 50 ° C., Preferably, it is 10000 mPa · s or less at 50 ° C. If it is such a viscosity range, after mixing a polyisocyanate component and a polyol component, an adhesive agent can be efficiently applied to a film (a barrier layer, a plastic film, etc.) with a solventless laminator.

  The two-component curable solventless adhesive of the present invention is used as an adhesive for laminating, for example, by laminating films such as a barrier layer and a plastic film as an adherend. It is done.

  Specifically, it is used for adhesion of a barrier layer and a plastic film, for example.

  A barrier layer is a layer which has the barrier property with respect to gas or a liquid, Comprising: For example, the film containing a metal or a metal oxide is mentioned. Specific examples include a metal foil or a plastic film including a barrier layer.

  A metal foil consists of aluminum, stainless steel, iron, copper, lead etc., for example, The thickness is 5-100 micrometers, Preferably it is 5-20 micrometers, More preferably, it is 5-15 micrometers.

  Examples of the plastic film including the barrier layer include a film in which an inorganic layer is formed on at least one surface of the plastic film.

  The inorganic layer can be formed by vapor deposition, sputtering, sol-gel method, or the like. The inorganic layer is made of, for example, a simple substance such as titanium, aluminum, or silicon, or an inorganic compound (such as an oxide) containing these elements. Preferably, the vapor deposition film which vapor-deposited both alumina and silica alone, or alumina and silica is mentioned.

  In addition, the plastic film containing a barrier layer can also laminate | stack an overcoat layer on the exposure side of a barrier layer.

  Plastic films include, for example, olefin polymers (eg, polyethylene, polypropylene, etc.), polyester polymers (eg, polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate, polyalkylene naphthalates, and their polyalkylene arylate units. ), Polyamide polymers (eg, nylon 6, nylon 66, etc.), vinyl polymers (eg, polyvinyl chloride, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer) Etc.). The thickness of the plastic film is usually 5 to 200 μm.

  As the plastic film or the plastic film including the barrier layer, any of an unstretched film (unstretched polyethylene, polypropylene, etc.) or a uniaxial or biaxially stretched film (biaxially stretched polypropylene, polyalkylene terephthalate, nylon, etc.) is used. be able to.

  Moreover, a plastic film can also be prepared as various co-extrusion films or the composite film which stuck plastic films beforehand.

  Furthermore, the surface of the plastic film and the barrier layer may be subjected to a surface treatment such as a corona discharge treatment, or may be subjected to a primer treatment with an anchor coating agent or the like. Moreover, it can also print suitably on a plastic film and a barrier layer.

  In the production of a composite film, an adhesive containing a polyisocyanate component and a polyol component is applied to, for example, one surface of a barrier layer or a plastic film by a solventless laminator, and the coated surface is applied to the other surface. The film is stuck to the surface of the barrier layer or plastic film, and then cured by curing at room temperature or under heating.

  As a composite film, a barrier layer and a plastic film may be attached (primary laminate) to produce a primary laminate composite film. Furthermore, another surface is provided on at least one surface of the primary laminate composite film. A secondary laminate composite film can also be produced by attaching a plastic film (secondary lamination).

  In the primary laminate, usually, either the barrier layer or the plastic film is sent out from the delivery roll, the other is stuck, wound up on the take-up roll, and heated / cured (for example, 25-60) as necessary. Curing at ℃).

  In the secondary laminating, the primary laminating composite film is usually sent out from the winding roll, and another plastic film is stuck, wound on the winding roll, and heated and cured as necessary.

  In the production of the secondary laminate composite film, the two-component curable solventless adhesive of the present invention may be used in both the primary laminate and the secondary laminate, or the primary laminate and the secondary laminate may be used. In either one, the two-component curable solventless adhesive of the present invention can be used, and in the other, another adhesive can be used.

  The laminating temperature (coating temperature) is usually 35 ° C. or higher, preferably 40 ° C. or higher. Although there is no upper temperature limit if lamination is possible, it is usually 100 ° C. or lower, preferably 90 ° C. or lower, and more preferably 85 ° C. or lower. As an upper and lower limit of temperature, at the time of lamination (coating), the adhesive is heated to 35 to 100 ° C., preferably 35 to 90 ° C., more preferably 40 to 80 ° C., and adjusted to an appropriate viscosity. . A suitable viscosity is 100 to 5000 mPa · s, preferably 300 to 3000 mPa · s at a temperature in the above range.

  In addition, if heating is 100 degrees C or less, since reaction with a polyisocyanate component and a polyol component can be suppressed before coating, prevention of excessive thickening and favorable workability | operativity can be ensured.

Incidentally, the coating amount of two-component curing type non solvent-based adhesives of the present invention, in each laminating step, for example, 0.5 to 5 g / ^{m 2,} preferably, 1 to 5 g / ^{m 2,} more preferably, 1.5 to 4.5 g / m ² . If the coating amount is less than 0.5 g / m ² , the adhesiveness may not be sufficiently developed and the appearance may be poor. On the other hand, if the coating amount exceeds 5 g / m ² , the end of the composite film In some cases, the adhesive leaks out of the film, resulting in poor quality of the composite film.

  The solventless laminating apparatus in which the two-component curable solventless adhesive of the present invention is used can be either a forward transfer type coating apparatus or a reverse transfer type coating apparatus (reverse coater).

  In the forward transfer type coating apparatus, an adhesive containing a polyisocyanate component and a polyol component is applied to one film passing between a pair of rolls rotating in the same direction at opposite positions. Thereafter, one of the films is stuck to the other film at the nip roller, thereby producing a composite film.

  In the reverse transfer type coating apparatus, an adhesive containing a polyisocyanate component and a polyol component is applied to one film that passes between a pair of rolls that rotate in opposite directions at opposite positions. Thereafter, one of the films is stuck to the other film at the nip roller, thereby producing a composite film.

  And the composite film stuck by the two-component curable solventless adhesive of the present invention can maintain excellent appearance and adhesive strength even under severe storage conditions after high-temperature sterilization treatment, It has a moderate pot life and can have excellent acid resistance.

  That is, since the two-component curable solventless adhesive of the present invention has an appropriate pot life, a composite film can be produced with good workability.

  Moreover, the composite film produced using the two-component curable solventless adhesive of the present invention is subjected to a hot water treatment at 100 ° C. or higher, for example, a hot water spray type, a hot water rotary type or a steam type. After high-temperature sterilization treatment, for example, at 60 ° C. for 4 weeks, it retains excellent appearance and adhesive strength even when stored at high temperatures for a long period of time, reduces the occurrence of delamination between layers, and It is excellent in interlayer adhesion, wet heat resistance, and high temperature sterilization ability without damaging the object.

  Furthermore, the composite film produced using the two-component curable solventless adhesive of the present invention is excellent in acid resistance, and even when the content is acidic, excellent interlayer adhesion can be ensured.

  Therefore, the two-component curable solventless adhesive of the present invention is suitably used for producing composite films in various industrial fields such as foods, beverages, pharmaceuticals and quasi drugs.

  In addition, according to the two-component curable solventless adhesive of the present invention, the reaction of the polyisocyanate component and the polyol component is moderately adjusted during the production of the composite film, and an abrupt increase in viscosity is suppressed. Sex can be secured.

  Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Production Example 1 (Production of polyester diol A)
283 g of isophthalic acid, 352 g of 1,3-butanediol, and 191 g of neopentyl glycol were charged into a reactor and subjected to an esterification reaction at 190 to 220 ° C. in a nitrogen stream. Then, after distilling predetermined water, polyesterdiol A was obtained by adding 124 g of adipic acid, 172 g of sebacic acid, and 0.01 g of titanium tetrabutoxide, and making it esterify at 180-220 degreeC under nitrogen stream. Polyesterdiol A had an average functional group number of 2.0 and a hydroxyl group equivalent of 250.

Production Example 2 (Production of diisocyanate group-terminated prepolymer A)
341 g of polyester diol A and 648 g of xylylene diisocyanate were charged into a reactor, and urethanized at 70 to 80 ° C. under a nitrogen stream. Then, diisocyanate group terminal prepolymer A was obtained by removing unreacted xylylene diisocyanate by thin film distillation.

  The average functional group number of the diisocyanate group-terminated prepolymer A was 2.0, the isocyanate group equivalent was 530, and the content of unreacted xylylene diisocyanate was 0.1% by mass.

Production Example 3 (Production of polyisocyanate component 1)
Polyisocyanate component 1 is obtained by uniformly mixing 500 g of diisocyanate group-terminated prepolymer A and 500 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol at 50 to 60 ° C. in a nitrogen stream. Got.

  The average functional group number of the polyisocyanate component 1 was 2.0, and the isocyanate group equivalent was 311.

Production Example 4 (Production of polyisocyanate component 2)
Polyisocyanate component 2 is obtained by uniformly mixing 400 g of diisocyanate group-terminated prepolymer A and 600 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol at 50 to 60 ° C. in a nitrogen stream. Got.

  The average functional group number of the polyisocyanate component 2 was 2.0, and the isocyanate group equivalent was 287.

Production Example 5 (Production of polyisocyanate component 3)
Polyisocyanate component 3 is obtained by uniformly mixing 300 g of diisocyanate group-terminated prepolymer A and 700 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of isocyanate groups with isobutanol at 50 to 60 ° C. in a nitrogen stream. Got.

  The average functional group number of the polyisocyanate component 3 was 2.0, and the isocyanate group equivalent was 267.

Production Example 6 (Production of polyisocyanate component 4)
Polyisocyanate component 4 was prepared by uniformly mixing 350 g of diisocyanate-terminated prepolymer A, 550 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol, and 100 g of a trimer of isophorone diisocyanate. Got.

  The average number of functional groups of the polyisocyanate component 4 was 2.09, and the isocyanate group equivalent was 277.

Production Example 7 (Production of polyisocyanate component 5)
Polyisocyanate component 5 is obtained by uniformly mixing 450 g of diisocyanate group-terminated prepolymer A, 500 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol, and 50 g of isophorone diisocyanate trimer. Got.

  The average functional group number of the polyisocyanate component 5 was 2.05, and the isocyanate group equivalent was 299.

Production Example 8 (Production of polyisocyanate component 6)
A polyisocyanate component 6 was prepared by uniformly mixing 470 g of a diisocyanate group-terminated prepolymer A, 500 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol, and 30 g of a trimer of isophorone diisocyanate. Got.

  The average number of functional groups of the polyisocyanate component 6 was 2.03, and the isocyanate group equivalent was 303.

Production Example 9 (Production of polyisocyanate component 7)
Polyisocyanate component 7 was prepared by uniformly mixing 700 g of diisocyanate group-terminated prepolymer A and 300 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol at 50 to 60 ° C. in a nitrogen stream. Got.

  The average functional group number of the polyisocyanate component 7 was 2.0, and the isocyanate group equivalent was 373.

Production Example 10 (Production of polyisocyanate component 8)
The polyisocyanate component 8 was prepared by uniformly mixing 50 g of the diisocyanate group-terminated prepolymer A and 950 g of an allophanate modified product of hexamethylene diisocyanate obtained by reacting a part of the isocyanate group with isobutanol at 50 to 60 ° C. in a nitrogen stream. Got.

  The average functional group number of the polyisocyanate component 8 was 2.0, and the isocyanate group equivalent was 227.

Production Example 11 (Production of polyol component 1)
An acid-modified product obtained by adding 5.8 g of trimellitic anhydride to 75.0 g of polyester diol A and partially acid-modified at 150 ° C., and a polypropylene polyol A (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 530) The polyol component 1 was obtained by uniformly mixing 17.1 g.

  The average functional group number of the polyol component 1 was 2.29, the hydroxyl group equivalent was 231, the acid value was 33, and the carboxyl group equivalent was 1650.

  In addition, 0.1 g of phosphoric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is then uniformly mixed with the polyol component 1, and γ-glycidoxypropyltrimethoxysilane (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.) is further mixed. 2 g was added and homogeneously mixed at 75 ° C.

Production Example 12 (Production of polyol component 2)
An acid-modified product obtained by adding 5.8 g of trimellitic anhydride to 75.0 g of polyester diol A and partially acid-modified at 150 ° C., and a polypropylene polyol B (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 250) The polyol component 2 was obtained by uniformly mixing 17.1 g.

  The average functional group number of the polyol component 2 was 2.16, the hydroxyl group equivalent was 289, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 2 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 13 (Production of polyol component 3)
An acid-modified product obtained by adding 5.8 g of trimellitic anhydride to 75.0 g of polyester diol A and partially acid-modified at 150 ° C., and a polypropylene polyol C (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 56) Polyol component 3 was obtained by uniformly mixing 17.1 g.

  The average functional group number of the polyol component 3 was 2.06, the hydroxyl group equivalent was 348, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 3 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 14 (Production of polyol component 4)
An acid-modified product obtained by adding 6.5 g of trimellitic anhydride to 74.3 g of polyester diol A and partially acid-modified at 150 ° C., and a polypropylene polyol A (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 530) The polyol component 4 was obtained by uniformly mixing 17.1 g.

  The average functional group number of the polyol component 4 was 2.29, the hydroxyl group equivalent was 235, the acid value was 39, and the carboxyl group equivalent was 1450.

  The polyol component 4 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 15 (Production of polyol component 5)
An acid-modified product obtained by adding 4.3 g of trimellitic anhydride to 76.5 g of polyester diol A and partially acid-modified at 150 ° C., and polypropylene polyol A (a propylene oxide adduct having glycerol as an initiator, hydroxyl value) 530) The polyol component 5 was obtained by uniformly mixing 17.1 g.

  The average functional group number of the polyol component 5 was 2.29, the hydroxyl group equivalent was 285, the acid value was 25, and the carboxyl group equivalent was 2230.

  The polyol component 5 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 16 (Production of polyol component 6)
An acid-modified product obtained by adding 5.8 g of trimellitic anhydride to 83.6 g of polyester diol A and partially acid-modified at 150 ° C., and a polypropylene polyol A (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 530) Polyol component 6 was obtained by uniformly mixing 8.5 g.

  The average functional group number of the polyol component 6 was 2.14, the hydroxyl group equivalent was 263, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 6 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 17 (Production of polyol component 7)
An acid-modified product obtained by adding 5.8 g of trimellitic anhydride to 67.0 g of polyester diol A, partially terminal acid-modified at 150 ° C., and polypropylene polyol A (propylene oxide adduct having glycerol as an initiator, hydroxyl value) 530) Polyol component 7 was obtained by uniformly mixing 25.1 g.

  The average functional group number of the polyol component 7 was 2.40, the hydroxyl group equivalent was 209, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 7 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 17 (Production of polyol component 8)
Polyol component 8 is obtained by adding 5.8 g of trimellitic anhydride to 84.1 g of polyester diol A and uniformly mixing the acid-modified product partially acid-modified at 150 ° C. with 8.0 g of trimethylolpropane. Got.

  The average functional group number of the polyol component 8 was 2.28, the hydroxyl group equivalent was 206, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 8 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 18 (Production of polyol component 9)
Polyol component 9 was prepared by adding 2.9 g of trimellitic anhydride to 87.0 g of polyester diol A and uniformly mixing the acid-modified product partially acid-modified at 150 ° C. with 8.0 g of trimethylolpropane. Got.

  The average functional group number of the polyol component 9 was 2.27, the hydroxyl group equivalent was 195, the acid value was 17, and the carboxyl group equivalent was 3320.

  The polyol component 9 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Production Example 19 (Production of polyol component 10)
73.8 g of polyester polyol A and 1.2 g of xylylene diisocyanate were charged into a reactor, and a urethanization reaction was performed at 70 to 80 ° C. under a nitrogen stream. To this, 5.8 g of trimellitic anhydride was added, and the acid-modified product partially acid-modified at 150 ° C. and polypropylene polyol A (propylene oxide adduct with glycerol as an initiator, hydroxyl value 530) 17. Polyol component 10 was obtained by uniformly mixing 1 g.

  The average functional group number of the polyol component 10 was 2.29, the hydroxyl group equivalent was 241, the acid value was 33, and the carboxyl group equivalent was 1650.

  The polyol component 10 was mixed with phosphoric acid and γ-glycidoxypropyltrimethoxysilane according to the same formulation as the polyol component 1.

Preparation of Examples and Comparative Examples By combining each polyisocyanate component and each polyol component obtained as described above in the number of parts (parts by mass) shown in Table 1, the two-component curable type of each example and each comparative example was obtained. A solvent-based adhesive was prepared.

  Using these two-component curable solventless adhesives, composite films were prepared by the method described below, and each composite film was subjected to a hot water resistance test, a content resistance test, and a pot life test to evaluate physical properties. . The results are shown in Table 2.

Preparation of Composite Film 10 parts by weight of Takelac A-310 (polyol component, Mitsui Chemicals) and 1 part by weight of Takenate A-3 (polyisocyanate component, Mitsui Chemicals) are mixed and diluted with ethyl acetate. Thus, a two-pack type organic solvent-based adhesive was prepared.

  Then, a polyethylene terephthalate film (thickness 12 μm, Lumirror P60, manufactured by Toray Film Processing Co., Ltd.) and an aluminum foil (thickness 9 μm, manufactured by Toyo Aluminum Co., Ltd.) are primarily laminated with a two-pack type organic solvent-based adhesive. A laminated composite film was produced.

Subsequently, the surface of the aluminum foil of the primary laminate composite film was subjected to the two-component curing type of each example and each comparative example using a solvent-free laminator (Okazaki Machinery Co., Ltd., non-sol laminator TNS-400-200). A solvent-based adhesive was applied (coating temperature 50 ° C., coating amount about 3.5 g / m ² ).

  Thereafter, an unstretched polypropylene film (thickness 70 μm, pyrene film-CTP1146 (manufactured by Toyobo Co., Ltd.)) was bonded to the coated surface to prepare a secondary laminate composite film. Thereafter, the secondary laminate composite film was cured at 50 ° C. for 3 days to cure the two-component curable solventless adhesive.

Hot water resistance test Using each secondary laminate composite film obtained above, a bag having a size of 13.0 × 17.5 cm was produced. The bag is filled with a premixed mixture of cereal vinegar (Mitsukanakanos) / salad oil (Nisshin Oillio Group) / tomato ketchup (Kagome) at a volume ratio of 1/1/1. did.

  The bag was sterilized with hot water while rotating at 8 rpm under a pressure of 0.35 MPa at 135 ° C. for 20 minutes, then the contents were taken out, and the adhesive strength between the aluminum foil / unstretched polypropylene film was 25 ° C. Under the environment, the specimen width was 15 mm, the tensile speed was 300 mm / min, and the measurement was performed by a T-type peel test.

Content-resistant property test The bag after the hot water treatment in the hot water resistance test was stored for 4 weeks in a 60 ° C thermostat, and then the appearance of the bag was visually evaluated. The evaluation criteria are shown below.

○: Good Δ: Slightly pear skin appearance ×: Pear skin appearance on the entire surface Further, the adhesive strength between the aluminum foil / unstretched polypropylene film was measured under the same conditions as described above.

  In Table 2, “CPP peeling” means interfacial peeling between an aluminum foil / unstretched polypropylene film, and “CPP surface peeling” means not interfacial peeling between an aluminum foil / unstretched polypropylene film. This indicates peeling of the surface layer of the stretched polypropylene film. Further, “aggregation peeling” indicates that peeling due to aggregation of the adhesive was confirmed.

Pot life test In each example and each comparative example, after mixing each polyisocyanate component and each polyol component uniformly at 50 ° C, the viscosity after 40 minutes was measured, and two-component curing of each example and each comparative example The pot life of the type solventless adhesive was evaluated. The evaluation criteria are shown below.

○: Viscosity is 10000 mPa · s or less Δ: Viscosity exceeds 10,000 mPa · s, and 12000 mPa · s or less X: Viscosity exceeds 12000 mPa · s Overall evaluation From the results of the above hot water resistance test, content resistance test and pot life test The two-component curable solventless adhesives of each Example and each Comparative Example were comprehensively evaluated. The evaluation criteria are shown below.

○: Good △: Almost good ×: Bad

Claims (6)

Including a polyisocyanate component and a polyol component;
The polyisocyanate component is
Containing a diisocyanate-terminated prepolymer obtained by reacting a diisocyanate containing an araliphatic diisocyanate and a diol containing a macrodiol,
The polyol component has an average functional group number exceeding 2,
Containing a diol including a macrodiol and a crosslinkable polyol having three or more secondary or tertiary hydroxyl groups, and / or
The diol and the crosslinkable polyol contain a urethane-modified polyol that is urethane-modified,
A two-component curable solventless adhesive, wherein the acid value is partially modified with a terminal acid so that the acid value exceeds 20 and is 40 or less.   2. The two-part curable solventless adhesive according to claim 1, wherein the cross-linkable polyol has a number average molecular weight of 100 to 2,000. The crosslinkable polyol is a trifunctional polypropylene polyol,
The two-component curable solventless adhesive according to claim 1 or 2, wherein 10 to 20 mass% of a crosslinkable polyol is contained with respect to the polyol component. The araliphatic diisocyanate is xylylene diisocyanate,
The two-component curable solventless adhesive according to claim 1 or 2, wherein the diisocyanate-terminated prepolymer is contained in an amount of 10 to 50% by mass relative to the polyisocyanate component.   The two-component liquid according to any one of claims 1 to 4, wherein the polyisocyanate component further contains at least one selected from aliphatic diisocyanate, alicyclic diisocyanate and derivatives thereof. A curable solventless adhesive. The aliphatic diisocyanate is hexamethylene diisocyanate;
The two-component curable solventless adhesive according to claim 5, wherein the alicyclic diisocyanate is isophorone diisocyanate.