JP2019112567A - adhesive - Google Patents

Abstract

To provide a laminate excellent in adhesive force (initial, and after filling of ingredients and storage), and tear property and useful as a packaging material.SOLUTION: There is provided an adhesive containing a polyol component and a polyisocyanate component, in which 70 mass% or more of (A1) having number average molecular weight of 4000 to 15000, manufactured by reacting at least one of trimellitic anhydride or trimellitic acid ester anhydride with a part of a hydroxyl group in a reaction product (a1) between a carboxyl group component containing 40 to 90 mol% of aromatic dibasic acid component in 100 mol% of the carboxyl group component, and a hydroxyl group component is contained in 100 mass% of the polyol component, and the polyisocyanate component contains 2 or more kinds of aliphatic polyisocyanate components.SELECTED DRAWING: None

Description

  The present invention relates to adhesives, and more particularly to adhesives suitable for forming packaging laminates for food, medical products, cosmetics and the like.

Soft packaging materials for packaging contents such as food, medical products and cosmetics are manufactured through bonding of various plastic films or bonding of plastic films with metallized films and metal foils via an adhesive layer. Laminates are used, and the adhesive layer is mainly produced by using a hydroxyl group / isocyanate adhesive.
In recent years, the range of use of soft packaging materials has been increasing from the viewpoint of resource saving and energy saving, and soft packaging materials are often used even for the contents used in conventional metal can containers and plastic bottle containers. It is coming.
For example, in Patent Document 1, a polyol and trimellitic anhydride and trimellitic anhydride are reacted with 10 to 70% by mass of trimellitic anhydride and 90 to 30% by mass of trimellitic anhydride. An adhesive containing a partially acid-modified polyol and a polyisocyanate is disclosed.

JP, 2005-132902, A

The soft packaging material is required to have a durability for storing the contents for a long time, and from the viewpoint of usability, the laminate is required to be tearable so that it can be easily opened.
However, due to the expansion of the range of use, depending on the contents, there is an increased risk of occurrence of delamination, bag breakage, and reduction in tearability after filling and storage.
The laminate formed from the adhesive disclosed in Patent Document 1 did not have sufficient tearability.
The present invention has been made in view of the above background, and an object of the present invention is to provide a laminate having excellent adhesive strength (initial and filling of contents, after storage) and tearability and useful as a packaging material.

This invention is comprised in view of the said subject, Comprising: It is related with the adhesive agent of following [1]-[4].
[1] An adhesive containing a polyol component and a polyisocyanate component, the adhesive satisfying the conditions (1) to (4) below.
(1) 70% by mass or more of a polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained in 100% by mass of the polyol component.
(2) The polyester polyol (A) is a hydroxyl group in the reaction product (a1) of a carboxyl group component containing 40 to 90 mol% of an aromatic dibasic acid component in 100 mol% of the carboxyl group component and a hydroxyl component. Part is a reaction product of an acid anhydride (A1), or a part of hydroxyl groups in the reaction product (a1) and a part of hydroxyl groups in the reaction product of diisocyanate (a2) And the acid anhydride (A2).
(3) The acid anhydride is at least one of trimellitic anhydride or trimellitic anhydride.
(4) The polyisocyanate component contains two or more aliphatic polyisocyanate components.

[2] Aliphatic polyisocyanate component is a nurate of hexamethylene diisocyanate, a burette of hexamethylene diisocyanate, an adduct wherein trimethylolpropane is added to hexamethylene diisocyanate, a nurate of isophorone diisocyanate, a burette of isophorone diisocyanate, It is two or more selected from the group consisting of an adduct of trimethylolpropane added to isophorone diisocyanate, a nurate of xylylene diisocyanate, a burette of xylylene diisocyanate, and an adduct of trimethylolpropane added to xylylene diisocyanate. The adhesive according to [1].

[3] Aliphatic polyisocyanate component is
A combination of a hexauret of hexamethylene diisocyanate and a burette of hexamethylene diisocyanate, or a combination of a buret of hexamethylene diisocyanate and a nurate of isophorone diisocyanate, or an adduct of xylylene diisocyanate with addition of trimethylolpropane and isophorone diisocyanate The adhesive according to [2], which is any one of a combination with an adduct to which trimethylolpropane is added.

[4] The adhesive according to any one of [1] to [3] which further satisfies all of the following conditions (5) to (7).
(5) In 100% by mass of the polyol component, 70 to 95% by mass of polyester polyol (A) having a number average molecular weight of 4000 to 15,000 and 5 to 30% by mass of polyester polyol (B) having a number average molecular weight of 500 to 3000 including.
(6) The acid value of the polyester polyol (B) is 5 mg KOH / g or less.
(7) The polyester polyol (B) is a reaction product (B1) of a carboxyl group component containing 40 to 70 mol% of an aromatic dibasic acid component in 100 mol% of the carboxyl group component, or a hydroxyl component, It is a reaction product (B2) of a part of hydroxyl groups in the reaction product (B1) and diisocyanate.

  By using the adhesive of the present invention, it is possible to provide a laminate having excellent adhesion (initial and filling of contents, after storage), tearability and useful as a packaging material.

The adhesive of the present invention contains a polyol component and a polyisocyanate component.
The polyol component in the present invention will be described.
The polyol component contains 70 to 100% by mass of polyester polyol (A) and 0 to 30% by mass of polyester polyol (B) in 100% by mass of the polyol component.

  The polyester polyol (A) is a polyester polyol having a number average molecular weight of 4000 to 15,000 composed of a carboxyl group component and a hydroxyl group component, and 40 to 90 mol of an aromatic dibasic acid component in 100 mol% of the carboxyl group component. % Is obtained by reacting an acid anhydride with a part of the hydroxyl group in the reaction product (a1) of the carboxyl group component and the hydroxyl group component, or in the reaction product (a1) An acid anhydride is further reacted with a part of the hydroxyl group in the reaction product (a2) of a part of the hydroxyl group and the diisocyanate (A2).

  Examples of the carboxyl group component include isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, and maleic anhydride Examples thereof include acids, itaconic anhydride and esters thereof. These can be used alone or in combination of two or more.

  Examples of the hydroxyl group component include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,6-hexanediol, neopentyl glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, Methylol propane, glycerin, 1,9-nonanediol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol and the like can be mentioned. These can be used alone or in combination of two or more.

  Examples of the acid anhydride include trimellitic anhydride and trimellitic anhydride. An example of trimellitic acid ester anhydride is ethylene glycol anhydrotrimellitate. The reaction of an acid anhydride is hereinafter sometimes referred to as acid modification.

  Examples of diisocyanate to be reacted with part of hydroxyl groups in the reaction product (a1) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5 -Naphthalene diisocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. can be mentioned. The reaction of these diisocyanates is hereinafter sometimes referred to as urethane modification.

  The number average molecular weight of the polyester polyol (A1) is 4000 to 15000, and preferably 6000 to 12000. In addition, the content of the aromatic dibasic acid component is 40 to 90 mol%, and 50 to 80 mol% in 100 mol% of the carboxyl group component (excluding the acid anhydride for modification) which is a component. Is preferred. By using such a polyester polyol, it is possible to obtain a soft packaging material which has good tear resistance and content resistance and good initial adhesion.

The adhesive of the present invention can contain 0 to 30% by mass of the following polyester polyol (B) in addition to the polyester polyol (A) in 100% by mass of the polyol component, and the polyester polyol (B) is 5 to 30 It is preferable to contain mass%. By using the following polyester polyol (B) in combination, the tearability is improved.
The polyester polyol (B) is composed of a carboxyl group component and a hydroxyl group component in the same manner as the polyester polyol (A), and 40 to 70 mol% of an aromatic dibasic acid component in 100 mol% of the carboxyl group component. It is a reaction product of a carboxyl group component and a hydroxyl group component (B1), or a reaction product of a part of hydroxyl groups in the reaction product (B1) with diisocyanate (B2).
The number average molecular weight of the polyester polyol (B) is 500 to 3,000, and preferably 1,000 to 2,000. Moreover, an acid value is 5 mgKOH / g or less, and it is preferable that it is 3 mgKOH / g.
By using such polyester polyols, tearability and initial adhesion are further improved.

  As the carboxyl group component, the hydroxyl group component and the diisocyanate, those exemplified for the polyester polyol (A) can be similarly exemplified.

  The measurement of a mass mean molecular weight (Mw) and a number average molecular weight (Mn) used Showa Denko GPC (gel permeation chromatography) "ShodexGPCSystem-21". GPC is a liquid chromatography that separates and quantifies a substance dissolved in a solvent based on the difference in molecular size, and the solvent is tetrohydrofuran, and the determination of molecular weight is performed in terms of polystyrene.

It is important that the adhesive of the present invention contains two or more aliphatic polyisocyanate components as the polyisocyanate component. By including two or more aliphatic polyisocyanate components, tearability, initial adhesion and adhesion after filling with contents are improved.
As an aliphatic polyisocyanate component, for example, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate Aliphatic diisocyanates such as 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanatomethyl caproate,
1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 4,4'-methylene bis (cyclohexyl isocyanate), methyl 2,4-cyclohexane diisocyanate, methyl 2 Cycloaliphatic diisocyanates such as, 6-cyclohexane diisocyanate, 1,4-bis (isocyanatomethyl) cyclohexane, 1,3-bis (isocyanatomethyl) cyclohexane, etc.
1,3- or 1,4-xylylene diisocyanate or mixtures thereof, ω, ω′-diisocyanate-1,4-diethylbenzene, 1,3- or 1,4-bis (1-isocyanate-1-methylethyl) benzene Or aromatic aliphatic diisocyanates such as mixtures thereof
A dimer, trimer (also known as a nurate), biuret, allophanate, a 2,4,6-oxadiazine trione ring derived from carbon dioxide gas and the above polyisocyanate monomer derived from the above polyisocyanate monomer The polyisocyanate which it has is mentioned.

In addition, there may be mentioned adducts (also called adducts) in which various glycol components shown below are added to the above-mentioned polyisocyanate monomer.
Examples of the glycol component used to form the adduct include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and the like. An adduct of a low molecular weight polyol with a molecular weight of less than 200 such as 1,3'-dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol etc. ~ 20,000 polyester polyols, polyether ester polyols, polyesteramide polyols, polycaprolactone polyols, polyvalerolactone polyols, Le polyols, polycarbonate polyols, polyhydroxy alkanes, castor oil, polyurethane polyol and the like.

  The adhesive of the present invention may be an aromatic diisocyanate such as toluene diisocyanate, diphenynylmethane diisocyanate, or a derivative thereof in addition to two or more aliphatic polyisocyanate components, as long as the object of the present invention is not impaired. Can also be included.

In the adhesive of the present invention, other additives known for adhesives can be added to the main component, ie, the polyol component, or to the curing agent, ie, the polyisocyanate component.
For example, reaction promoters can be used.
Examples of reaction accelerators include metal catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dimaleate, etc .; Tertiary amines such as diazabicyclo (4,3,0) nonene-5, 6-dibutylamino-1,8-diazabicyclo (5,4,0) undecen-7; reactive tertiary amines such as triethanolamine And the like, and one or more reaction accelerators selected from these groups can be used.

A silane coupling agent can be used from a viewpoint of improving the adhesive strength with respect to metal-type raw materials, such as metal foil. As a silane coupling agent, for example, vinyl trimethoxysilane, trialkoxysilane having a vinyl group such as vinyltriethoxysilane, 3-aminopropyltriethoxysilane, N- (2-aminoethyl) 3-aminopropyltrimethoxysilane Etc. having an amino group such as; glycidyl group such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, etc. A trialkoxysilane is mentioned. These can be used alone or in any combination of two or more.
The addition amount of the silane coupling agent is preferably 0.1 to 5 parts by weight, and more preferably 0.2 to 3 parts by weight with respect to 100 parts by weight of the solid content of the polyol component (A). By adding the silane coupling agent in the above range, the adhesive strength to the metal foil can be improved.

  Similarly, from the viewpoint of improving the adhesive strength to a metal-based material such as a metal foil, phosphoric acid or a phosphoric acid derivative can be used. Among phosphoric acids or their derivatives, any phosphoric acid may be used as long as it has at least one free oxygen acid, such as hypophosphorous acid, phosphorous acid, orthophosphoric acid, hypophosphoric acid, etc. Examples thereof include condensed phosphoric acids such as phosphoric acids, metaphosphoric acids, pyrophosphoric acids, tripolyphosphoric acids, polyphosphoric acids and ultraphosphoric acids. Moreover, as a derivative of phosphoric acid, those partially esterified with alcohols and the like in a state in which at least one of the above-described phosphoric acids is left free can be mentioned. Examples of these alcohols include aliphatic alcohols such as methanol, ethanol, ethylene glycol and glycerin, and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol and phlorogricinol. Phosphoric acid or a derivative thereof may be used in combination of two or more. The addition amount of phosphoric acid or its derivative is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight, based on the solid content of the adhesive, and 0.05 to 1%. It is particularly preferred that it is wt%.

In order to improve the appearance of the laminate, known leveling agents or antifoaming agents can also be added to the main agent. As the leveling agent, for example, polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyetherester-modified hydroxyl group-containing polydimethylsiloxane, acrylic copolymer And methacrylic copolymer, polyether modified polymethyl alkyl siloxane, acrylic acid alkyl ester copolymer, methacrylic acid alkyl ester copolymer, lecithin and the like.
As an antifoamer, well-known things, such as a silicone resin, a silicone solution, the copolymer of alkyl vinyl ether, acrylic acid alkyl ester, and methacrylic acid alkyl ester, etc. are mentioned.

The soft packaging material obtained using the adhesive of the present invention can be produced, for example, by a commonly used method.
For example, the outer layer side resin film layer (11) and the metal foil layer (13) are laminated using the adhesive of the present invention to obtain an intermediate laminate. Next, the heat seal layer (14) can be laminated on the surface of the metal foil layer (13) of the intermediate laminate using the inner layer side adhesive.
Alternatively, the metal foil layer (13) and the heat seal layer (14) are laminated using an inner layer adhesive to obtain an intermediate laminate. Subsequently, the metal foil layer (13) and the outer layer side resin film layer (11) of the intermediate laminate can be laminated using the adhesive of the present invention.
In the former case, the adhesive of the present invention is applied to one side of either the outer layer side resin film layer (11) or the metal foil layer (13), and after the solvent is volatilized, the adhesive layer is the other. It is preferable to stack the substrate of the above under heat and pressure and then to age at normal temperature to less than 100 ° C. to cure the adhesive layer. When the temperature is 100 ° C. or higher, the outer layer side resin film layer (11) is thermally shrunk to lower the breaking elongation and the breaking stress which affect the molding, or the curling due to the thermal contraction to lower the molding productivity. The total amount of adhesive is preferably about 1 to 15 g / m ² .
Similarly in the latter case, the adhesive of the present invention may be applied to either the outer layer side resin film layer (11) or the metal foil layer (13) side of the intermediate laminate.

When the adhesive is applied to the substrate, in order to adjust the coating liquid to an appropriate viscosity, a solvent may be included within a range that does not affect the substrate in the drying step.
As the solvent, ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl acetate and methoxyethyl acetate, ethers such as diethyl ether and ethylene glycol dimethyl ether Compounds, aromatic compounds such as toluene and xylene, aliphatic compounds such as pentane and hexane, halogenated hydrocarbon compounds such as methylene chloride, chlorobenzene and chloroform, alcohols such as ethanol, isopropyl alcohol and normal butanol, water and the like Be These solvents may be used alone or in combination of two or more.

  In the present invention, as a device for applying a polyurethane adhesive, a comma coater, a dry laminator, a roll knife coater, a die coater, a die coater, a roll coater, a bar coater, a gravure roll coater, a reverse roll coater, a blade coater, a gravure coater, microgravure A coater etc. are mentioned.

  Next, the present invention will be more specifically described by way of examples and comparative examples. All% in Examples and Comparative Examples mean% by mass.

Further, the acid value and the hydroxyl value were determined as follows.
<Measurement of acid number (AV)>
Approximately 1 g of a sample (polyester polyol solution) is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2/1) is dissolved. To this, add phenolphthalein TS as an indicator and hold for 30 seconds. It is then titrated with 0.1 N alcoholic potassium hydroxide solution until the solution is pinkish. The acid value was determined by the following formula (unit: mg KOH / g).
Acid value (mg KOH / g) = (5.611 x a x F) / S
However, S: amount of sample collected (g)
a: Consumption of 0.1 N alcoholic potassium hydroxide solution (ml)
F: titer of 0.1 N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value (OHV)>
Approximately 1 g of a sample (polyester polyol solution) is accurately weighed in a stoppered Erlenmeyer flask, and 100 ml of a mixed solution of toluene / ethanol (volume ratio: toluene / ethanol = 2/1) is dissolved. Furthermore, exactly 5 ml of an acetylating agent (a solution in which 25 g of acetic anhydride was dissolved in pyridine to make a volume of 100 ml) was added and stirred for about 1 hour. To this, add phenolphthalein test solution as an indicator and hold for 30 seconds. It is then titrated with 0.1 N alcoholic potassium hydroxide solution until the solution is pinkish.
The hydroxyl value was determined by the following formula (unit: mg KOH / g).
Hydroxyl value (mg KOH / g)
= [{(B-a) x F x 28.05} / S] + D
However, S: amount of sample collected (g)
a: Consumption of 0.1 N alcoholic potassium hydroxide solution (ml)
b: Consumption of empty 0.1 N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1 N alcoholic potassium hydroxide solution D: Acid value (mg KOH / g)

Synthesis Example 1 Synthesis of Polyester Polyol A-1 425.6 g (2.6 mol) of isophthalic acid, 160.4 g (1.1 mol) of adipic acid, 81.8 g (1.3 mol) of ethylene glycol, neopentyl glycol 228. Charge 5 g (2.2 mol), 103.7 g (0.88 mol) of 1,6-hexanediol, carry out an esterification reaction at 200 to 230 ° C. for 6 hours, distill off a predetermined amount of water, and then add tetraisobutyl titanate Add 0.01 g, gradually reduce pressure and heat at 1.0 to 2.7 hPa, 230 to 250 ° C. for 6 hours to distill off a part of the glycol component, carry out a transesterification reaction, and polyester polyol intermediate I got
Next, 4.5 g of trimellitic anhydride is added to 300 g of the obtained polyester polyol intermediate, and the mixture is maintained at 160 ° C. for 2 hours, and polyester polyol A-1 having a number average molecular weight of 10,000 and an acid value of 8.1 mg / KOH. I got
Assuming that the excess hydroxyl group component is almost equally distilled off, and the carboxylic acid component and the hydroxyl group component are each 100 mol%, the composition of the obtained polyester polyol A-1 is isophthalic acid as shown in Table 1: Adipic acid = 70:30 (mol%), ethylene glycol: neopentyl glycol: 1, 6-hexanediol = 30: 50: 20 (mol%).
Furthermore, this polyester polyol was adjusted to 50% of non volatile matter with ethyl acetate, and the solution of polyol A-1 was obtained.

(Synthesis examples 2 to 5, 7 to 11)
In the same manner as in Synthesis Example 1 except that the carboxylic acid component and the hydroxyl component are charged so that the product has the composition (mol%) shown in Table 1, and the pressure and time of the transesterification reaction are changed, The solution of polyester polyol A-2 to 5 and 7 to 11 was obtained.

Synthesis Example 6
To 500 g of a polyester polyol intermediate obtained in the same manner as in Synthesis Example 1 except that the carboxylic acid component and the hydroxyl component are charged so as to obtain the composition shown in Table 1, and the pressure and time of transesterification are changed. 5 g of isophorone diisocyanate (hereinafter referred to as IPDI) was gradually added, and the reaction was carried out at 150 ° C. for about 2 hours to obtain a polyester polyurethane polyol.
To 300 g of this polyester polyurethane polyol, 4.5 g of trimellitic anhydride was added, reacted at 160 ° C. for about 2 hours, adjusted to 50% nonvolatile content with ethyl acetate, and a solution of polyol A-6 was obtained.

Synthesis Example 12
The polyester polyol intermediate in Synthesis Example 1 was adjusted to 50% non-volatile content with ethyl acetate to prepare a solution of polyol A-12.

Synthesis Example 101 Synthesis of Polyester Polyol B-1 308.9 g (1.9 mol) of terephthalic acid, 307.6 g (1.5 mol) of sebacic acid, 109.1 g (1.8 mol) of ethylene glycol, neopentyl glycol 274. Charge 5 g (2.6 mol), perform esterification reaction at 200 to 230 ° C. for 6 hours, distill off a predetermined amount of water, add 0.01 g of tetraisobutyl titanate and gradually reduce pressure, 20 to 130 hPa, The ester exchange reaction was carried out while heating at 230 to 250 ° C. for 3 hours to distill off a part of the glycol component to obtain an acid value of 1 mg / KOH and a molecular weight of 1,500 polyester polyol B-1.
Assuming that the excess hydroxyl group component is almost equally distilled off, and the carboxylic acid component and the hydroxyl group component are each 100 mol%, the composition of the obtained polyester polyol B-1 is terephthalic acid as shown in Table 2: Sebacic acid = 55: 45 (mol%), ethylene glycol: neopentyl glycol = 40: 60 (mol%).
The polyester polyol was adjusted to 50% by mass of non volatile matter with ethyl acetate to obtain a solution of polyol solution B-1.

(Synthesis examples 102 to 105, 107 to 110)
The non-volatile content was adjusted to 50% by mass in the same manner as in Synthesis Example 101 except that the carboxylic acid component and the hydroxyl group component were used so that the product had the composition shown in Table 2, and the pressure and time of transesterification were changed. Then, a solution of polyester polyols B-2 to B-5 and B-7 to 10 was obtained.

(Composition example 106)
IPDI: 1.5 g is added to 300 g of polyester polyol B-1 obtained in Synthesis Example 101, and the reaction is carried out at 150 ° C. for about 2 hours to adjust the nonvolatile content to 50% by mass, and polyester polyurethane polyol B-6. Solution was obtained.

(Composition example 111)
3.6 g of trimellitic anhydride is added to 300 g of the polyester polyol B-1 obtained in Synthesis Example 101, and the mixture is maintained at 160 ° C. for 2 hours to adjust the nonvolatile content to 50% by mass, and the acid value is 7 mg / KOH A solution of polyester polyol B-11 was obtained.

Preparation Example 1 Preparation of Polyisocyanate Solution C-1 A biuret of hexamethylene diisocyanate (hereinafter referred to as HDI-biuret) and a nurate of hexamethylene diisocyanate (hereinafter referred to as HDI-nurate) are 60:40 (mass) The solution was mixed in a ratio and diluted with ethyl acetate to obtain a solution of polyisocyanate C-1 having a nonvolatile content of 50% by mass.

(Adjustment examples 2 to 9, 13, 14)
An adduct of trimethylolpropane added to HDI (hereinafter HDI-TMP),
Nude body of IPDI (hereinafter, IPDI-nurate),
Adducts obtained by adding trimethylolpropane to xylylene diisocyanate (hereinafter XDI-TMP),
Adduct in which trimethylolpropane is added to toluene diisocyanate (hereinafter TDI-TMP)
An adduct obtained by adding trimethylolpropane to diphenynylmethane diisocyanate (hereinafter MDI-TMP),
It mixed in the ratio shown in Table 3 respectively, diluted with ethyl acetate, and obtained the solution of polyisocyanate C-2-9, 13 and 14 of 50 mass% of non volatile matter.

(Examples of adjustment 10 to 12)
HDI-biuret, HDI-TMP, and IPDI-TMP were each diluted with ethyl acetate to obtain a solution of polyisocyanate C-10 to C-12 having a nonvolatile content of 50% by mass.

Example 1
100 parts by mass of a polyol A-1 solution having a nonvolatile content of 50% by mass, 10 parts by mass of a polyisocyanate solution C-1 having a nonvolatile content of 50% by mass, γ-glycidoxypropyltrimethoxysilane and ethyl acetate as a silane coupling agent Were blended at a ratio (parts by mass) shown in Table 4 to obtain an adhesive solution having a nonvolatile content of 30% by mass.
The resulting adhesive solution was used to form a laminate by the following method, and the adhesive strength (initially, after the content resistance test) and the tearability test were carried out as described below for each of the obtained laminates. . The results are shown in Table 4.

(Examples 2 to 7), (Comparative Examples 1 to 3)
An adhesive solution was obtained and evaluated in the same manner as in Example 1 according to the composition shown in Table 4. The results are shown in Table 4 together.

(Example 8)
Use 85 parts by mass of polyol A-1 solution with 50% by mass of nonvolatile matter, 15 parts by mass of polyol B-1 solution with 50% by mass of nonvolatile matter, and 17 parts by mass of polyisocyanate solution C-1 with 50% by mass of nonvolatile matter An adhesive solution was obtained and evaluated in the same manner as in Example 1 according to the composition shown in Table 5 except that the adhesive solution was used. The results are shown in Table 5 together.

(Examples 9 to 29), (Comparative examples 4 to 19)
An adhesive solution was obtained and evaluated in the same manner as in Example 1 according to the compositions shown in Tables 4 to 7. The results are shown in Tables 4 to 7 together.

(Creating a three-layer laminate)
Three-layer composite of polyethylene terephthalate (hereinafter PET) film (thickness 12 μm) / aluminum (hereinafter AL) foil (thickness 9 μm) / unstretched polyethylene (hereinafter PE) film (thickness 50 μm, surface corona discharge treatment) The laminate was made by the method described below.
That is, after providing a printing layer on a PET film, an adhesive solution is applied to the PET film at normal temperature on the printing layer to volatilize the solvent, and then the coated surface is bonded to the aluminum foil surface, and an intermediate laminate I got
Furthermore, an adhesive solution is similarly applied to the aluminum foil surface of the intermediate laminate, and after the solvent is volatilized, the coated surface is bonded to a PE film and kept at 40 ° C. for 4 days to form a three-layer laminate. did.

(Adhesive strength test-initial, after content resistance test)
<Initial>
A test piece of 15 mm x 300 mm in size is made from the three-layer laminate prepared as described above, and using a tensile tester, peeling speed by T-type peeling under conditions of a temperature of 20 ° C and a relative humidity of 65%. The laminate strength (N / 15 mm) between the AL foil / PE film was measured at 30 cm / min. The numerical values in Tables 4 to 7 are average values of five test pieces. The practical range of laminate strength is 4 N / 15 mm or more.

<After content resistance test>
Each three-layer laminate was used to make pouches of 9 cm × 13 cm in size (PE films are positioned inside) and filled with ketchup and conditioner as contents.
After storing this pouch at 60 ° C. for 2 weeks, the contents were emptied and a test piece was cut out from each pouch, and the adhesive strength (N / 15 mm) between the AL foil / PE film was measured as in the initial stage.
The practical range of laminate strength after the test is 3 N / 15 mm or more.

(Creating a laminate for tear test)
A laminate of nylon (NY) film (thickness 15 μm) / printed / unstretched polyethylene (PE) film (thickness 50 μm, surface corona discharge treatment) was prepared by the method described below.
That is, after providing a printing layer on NY film, the adhesive solution is applied at normal temperature on the printing layer, the solvent is volatilized off, the coated surface is bonded to the PE film, and kept at 40 ° C. for 4 days A laminate was created.

(Tearability test)
A cut was made at the end of the laminate with a cutter, and the tearability at the time of manual tearing was evaluated.
(Evaluation criteria)
:: tearing without resistance O: slightly resistance but tearing Δ: some elongation of PE film somewhat but somehow tearing Δ ×: onset of tearing and / or obvious elongation of PE film on the way.
×: can not tear at all

Claims (4)

An adhesive comprising a polyol component and a polyisocyanate component, wherein
Adhesive which fulfills all the conditions of the following conditions (1)-(4).
(1) 70% by mass or more of a polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained in 100% by mass of the polyol component.
(2) The polyester polyol (A) is a hydroxyl group in the reaction product (a1) of a carboxyl group component containing 40 to 90 mol% of an aromatic dibasic acid component in 100 mol% of the carboxyl group component and a hydroxyl component. Part is a reaction product of an acid anhydride (A1), or a part of hydroxyl groups in the reaction product (a1) and a part of hydroxyl groups in the reaction product of diisocyanate (a2) And the acid anhydride (A2).
(3) The acid anhydride is at least one of trimellitic anhydride or trimellitic anhydride.
(4) The polyisocyanate component contains two or more aliphatic polyisocyanate components.   Aliphatic polyisocyanate component: a nurate of hexamethylene diisocyanate, a burette of hexamethylene diisocyanate, an adduct obtained by adding trimethylolpropane to hexamethylene diisocyanate, a nurate of isophorone diisocyanate, a burette of isophorone diisocyanate, isophorone diisocyanate The two or more members selected from the group consisting of adducts in which trimethylolpropane is added, nurates of xylylene diisocyanate, burettes of xylylene diisocyanate, and adducts in which trimethylolpropane is added to xylylene diisocyanate. The adhesive according to 1). Aliphatic polyisocyanate component is
A combination of a hexauret of hexamethylene diisocyanate and a burette of hexamethylene diisocyanate, or a combination of a buret of hexamethylene diisocyanate and a nurate of isophorone diisocyanate, or an adduct of xylylene diisocyanate with addition of trimethylolpropane and isophorone diisocyanate The adhesive according to claim 2, which is any one of a combination with an adduct to which trimethylolpropane is added. The adhesive according to any one of claims 1 to 3, further satisfying all conditions of the following conditions (5) to (7).
(5) In 100% by mass of the polyol component, 70 to 95% by mass of polyester polyol (A) having a number average molecular weight of 4000 to 15,000 and 5 to 30% by mass of polyester polyol (B) having a number average molecular weight of 500 to 3000 including.
(6) The acid value of the polyester polyol (B) is 5 mg KOH / g or less.
(7) The polyester polyol (B) is a reaction product (B1) of a carboxyl group component containing 40 to 70 mol% of an aromatic dibasic acid component in 100 mol% of the carboxyl group component, or a hydroxyl component, It is a reaction product (B2) of a part of hydroxyl groups in the reaction product (B1) and diisocyanate.