JP7030266B2 - glue - Google Patents

Description

The present invention relates to an adhesive, and more particularly to an adhesive suitable for forming a packaging laminate for foods, medical products, cosmetics and the like.

Flexible packaging materials for packaging contents such as foods, medical products, and cosmetics are manufactured by bonding various plastic films to each other or bonding plastic films to metal vapor-deposited films or metal foils via an adhesive layer. Laminates are used, and the adhesive layer is mainly made by using a hydroxyl group / isocyanate-based adhesive.
In recent years, from the viewpoint of resource saving and energy saving, the range of use of flexible packaging materials has increased, and flexible packaging materials are often used for the contents used in conventional metal can containers and plastic bottle containers. It's coming.
For example, in Patent Document 1, a polyol is reacted with trimellitic anhydride and trimellitic acid ester anhydride at a ratio of 10 to 70% by mass of trimellitic anhydride and 90 to 30% by mass of trimellitic acid ester anhydride. Disclosed are adhesives containing partially acid-modified polyols and polyisocyanates.

Japanese Unexamined Patent Publication No. 2005-132902

The flexible packaging material needs to have durability for storing the contents for a long period of time, and from the viewpoint of usability, it needs to have tearability of the laminate so that it can be easily opened.
However, due to the expansion of the range of use, there is an increasing risk that delamination, bag tearing, and deterioration of tearability may occur after filling or storage depending on the contents.
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 which is excellent in adhesive strength (initial and after filling and storage of contents) and tearability and is useful as a packaging material.

The present invention has been made in view of the above problems, and relates to the following adhesives [1] to [4].
[1] An adhesive containing a polyol component and a polyisocyanate component, which satisfies all of the following conditions (1) to (4).
(1) In 100% by mass of the polyol component, 70% by mass or more of the polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained.
(2) The polyester polyol (A) is one of the hydroxyl groups in the reaction product (a1) of the carboxyl group component containing 40 to 90 mol% of the aromatic dibasic acid component in 100 mol% of the carboxyl group component and the hydroxyl group component. A part of the hydroxyl group formed by reacting an acid anhydride with the portion (A1), or a part of the hydroxyl group in the reaction product (a1) and a part of the hydroxyl group in the reaction product (a2) with the diisocyanate. Further, it is obtained by reacting an acid anhydride (A2).
(3) The acid anhydride is at least one of trimellitic acid anhydride and trimellitic acid ester anhydride.
(4) The polyisocyanate component contains two or more kinds of aliphatic polyisocyanate components.

[2] The aliphatic polyisocyanate component is a hexamethylene diisocyanate nurate body, a hexamethylene diisocyanate burette body, an adduct body in which trimethyl propane is added to hexamethylene diisocyanate, an isophorone diisocyanate nurate body, an isophorone diisocyanate burette body, and the like. Two or more selected from the group consisting of an adduct body in which trimethylol propane is added to isophorone diisocyanate, a nurate body of xylylene diisocyanate, a bullet body of xylylene diisocyanate, and an adduct body in which trimethylol propane is added to xylylene diisocyanate. , [1].

[3] The aliphatic polyisocyanate component is
A combination of hexamethylene diisocyanate nurate and hexamethylene diisocyanate burette, hexamethylene diisocyanate burette and isophorone diisocyanate nurate, or an adduct and isophorone diisocyanate with trimethylolpropane added to xylylene diisocyanate. The adhesive according to [2], which is one of the combinations with an adduct body 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 the polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained, and 5 to 30% by mass of the 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 mgKOH / 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 and a hydroxyl group component, or is It is a reaction product (B2) of a part of a hydroxyl group in the reaction product (B1) and a diisocyanate.

By using the adhesive of the present invention, it is possible to provide a laminate which is excellent in adhesive strength (initial and after filling and storage of contents) and tearability and is 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 the polyester polyol (A) and 0 to 30% by mass of the 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 15000 composed of a carboxyl group component and a hydroxyl group component, and 40 to 90 mol of an aromatic dibasic acid component is contained in 100 mol% of the carboxyl group component. % Is reacted with 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 (A1), or in the reaction product (a1). It is a product (A2) obtained by further reacting an acid anhydride with a part of the hydroxyl group in the reaction product (a2) of a part of the hydroxyl group and the diisocyanate.

Examples of the carboxyl group component include isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic acid anhydride, adipic acid, azelaic acid, sebacic acid, succinic acid, glutaric acid, tetrahydrophthalic acid anhydride, hexahydrophthalic acid anhydride, and maleine anhydride. Examples thereof include an acid, an isophthalic anhydride and an ester compound 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, and tri. Examples thereof include methylolpropane, glycerin, 1,9-nonanediol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, acrylic polyol, polyurethane polyol and the like. These can be used alone or in combination of two or more.

Examples of the acid anhydride include trimellitic acid anhydride and trimellitic acid ester anhydride. Examples of the trimellitic acid ester anhydride include ethylene glycol anhydrotrimeritate. The reaction of acid anhydride is hereinafter referred to as acid denaturation.

Examples of the diisocyanate to be reacted with a part of the hydroxyl group in the reaction product (a1) include 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, and 1,5. -Naphthalenedi isocyanate, hexamethylene diisocyanate, hydrogenated diphenylmethane diisocyanate and the like can be mentioned. The reaction of these diisocyanates is hereinafter referred to as urethane modification.

The number average molecular weight of the polyester polyol (A1) is 4000 to 15000, preferably 6000 to 12000. Further, the content of the aromatic dibasic acid component is 40 to 90 mol% in 100 mol% of the carboxyl group component (excluding the acid anhydride for denaturation) which is a constituent component, and is 50 to 80 mol%. Is preferable. By using such a polyester polyol, it is possible to obtain a flexible packaging material having good tearability and content resistance and good initial adhesive strength.

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 5 to 30 polyester polyol (B). It preferably contains% by mass. By using the following polyester polyol (B) in combination, the tearability is improved.
Like the polyester polyol (A), the polyester polyol (B) is composed of a carboxyl group component and a hydroxyl group component, and the aromatic dibasic acid component is 40 to 70 mol% in 100 mol% of the carboxyl group component. It is a reaction product (B1) of a carboxyl group component containing a hydroxyl group component and a hydroxyl group component, or a reaction product (B2) of a part of a hydroxyl group in the reaction product (B1) and a diisocyanate.
The number average molecular weight of the polyester polyol (B) is 500 to 3000, preferably 1000 to 2000. The acid value is 5 mgKOH / g or less, preferably 3 mgKOH / g.
By using such a polyester polyol, the tearability and the initial adhesive strength are further improved.

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

The mass average molecular weight (Mw) and the number average molecular weight (Mn) were measured by using GPC (gel permeation chromatography) "Shodex GPC System-21" manufactured by Showa Denko KK. GPC is a liquid chromatography in which a substance dissolved in a solvent is separated and quantified by the difference in its molecular size. The solvent is tetrohydrofuran, and the molecular weight is determined in terms of polystyrene.

It is important that the adhesive of the present invention contains two or more kinds of aliphatic polyisocyanate components as the polyisocyanate component. The inclusion of two or more aliphatic polyisocyanate components improves tearability, initial and adhesive strength after filling and storing the contents.
Examples of the aliphatic polyisisethylene component include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butyrenidiisisis, 2,3-butyrenisisisocyanis, and 1,3-butyrenisisisocyanis. , 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanis aliphatic diisocyanate such as methylcaproate,
1,4-Cyclohexanediisocyanate, 1,3-cyclohexanediisocyanate, 3-isocyanatemethyl-3,5,5-trimethylcyclohexylisocyanate, 4,4'-methylenebis (cyclohexylisocyanate), methyl2,4-cyclohexanediisocyanate, methyl2 , 6-Cyclohexanediisocyanate, 1,4-bis (isocyanatemethyl) cyclohexane, 1,3-bis (isocyanatemethyl) cyclohexane and other alicyclic diisocyanates,
1,3- or 1,4-xylylene diisocyanate or a mixture thereof, ω, ω'-diisocyanate-1,4-diethylbenzene, 1,3- or 1,4-bis (1-isocyanate-1-methylethyl) benzene Or aromatic aliphatic diisocyanate such as a mixture thereof,
A 2,4,6-oxadiazine trione ring derived from the polyisocyanate monomer, such as dimer, trimmer (also known as nurate), biuret, allophanate, carbon dioxide gas and the polyisocyanate monomer. Examples thereof include polyisocyanates having.

In addition, an adduct (also known as an adduct) in which various glycol components shown below are added to the polyisocyanate monomer can be mentioned.
Examples of the glycol component used for forming the adduct include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 3. , 3'-Dimethylolpropane, cyclohexanedimethanol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerol, trimethylolpropane, pentaerythritol, sorbitol and other adducts such as low molecular weight polyols with a molecular weight of less than 200, or an adduct having a molecular weight of 200. Examples thereof include ~ 20,000 polyester polyols, polyether ester polyols, polyesteramide polyols, polycaprolactone polyols, polyvalerolactone polyols, acrylic polyols, polycarbonate polyols, polyhydroxyalkanes, castor oil, polyurethane polyols and the like.

In addition to two or more kinds of aliphatic polyisocyanate components, the adhesive of the present invention is an aromatic diisocyanate such as toluene diisocyanate and diphenylenylmethane diisocyanate, and derivatives thereof, 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 agent, that is, the polyol component, or the curing agent, that is, the polyisocyanate component.
For example, a reaction accelerator can be used.
Examples of the reaction accelerator include metal-based catalysts such as dibutyltin diacetate, dibutyltin dilaurate, dioctyltin dilaurate, and dibutyltin dimarate; 1,8-diaza-bicyclo (5,4,0) undecene-7,1,5. -3rd-level amines such as diazabicyclo (4,3,0) nonen-5,6-dibutylamino-1,8-diazabicyclo (5,4,0) undecene-7; reactive tertiary amines such as triethanolamine Etc., and one or more reaction promoters selected from these groups can be used.

A silane coupling agent can be used from the viewpoint of improving the adhesive strength to a metal-based material such as a metal foil. Examples of the silane coupling agent include trialkoxysilane having a vinyl group such as vinyltrimethoxysilane and vinyltriethoxysilane, 3-aminopropyltriethoxysilane, and N- (2-aminoethyl) 3-aminopropyltrimethoxysilane. Trialkoxysilane having an amino group such as 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane having a glycidyl group such as Examples thereof include trialkoxysilane. These can be used alone or in any combination of two or more.
The amount of the silane coupling agent added is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 3 parts by weight, based on 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, phosphoric acid or a phosphoric acid derivative can be used from the viewpoint of improving the adhesive strength to a metal-based material such as a metal foil. Of the phosphoric acid or its derivatives, the phosphoric acid may be any one having at least one free oxygen acid, for example, hypophosphoric acid, phosphoric acid, orthophosphoric acid, hypophosphoric acid and the like. Examples thereof include condensed phosphoric acids such as phosphoric acid, metaphosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, polyphosphoric acid and ultraphosphoric acid. Examples of the phosphoric acid derivative include those in which the above-mentioned phosphoric acid is partially esterified with alcohols while leaving at least one free oxygen acid. Examples of these alcohols include fatty alcohols such as methanol, ethanol, ethylene glycol and glycerin, and aromatic alcohols such as phenol, xylenol, hydroquinone, catechol and fluoroglycinol. Phosphoric acid or a derivative thereof may be used in combination of two or more. The amount of phosphoric acid or a derivative thereof added is preferably 0.01 to 10% by weight, more preferably 0.05 to 5% by weight, and 0.05 to 1% based on the solid content of the adhesive. It is particularly preferable to be% by weight.

A known leveling agent or defoaming agent may be added to the main agent for the purpose of improving the appearance of the laminate. Examples of the leveling agent include polyether-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polymethylalkylsiloxane, polyester-modified hydroxyl group-containing polydimethylsiloxane, polyether ester-modified hydroxyl group-containing polydimethylsiloxane, and acrylic copolymer. , Methacrylic copolymers, polyether-modified polymethylalkylsiloxanes, acrylic acid alkyl ester copolymers, methacrylic acid alkyl ester copolymers, lecithin and the like.
Examples of the defoaming agent include known ones such as a silicone resin, a silicone solution, and a copolymer of an alkyl vinyl ether, an acrylic acid alkyl ester, and a methacrylic acid alkyl ester.

The flexible packaging material obtained by 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 metal foil layer (13) surface 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 side adhesive to obtain an intermediate laminate. Next, the metal foil layer (13) of the intermediate laminate and the outer layer side resin film layer (11) 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 the base material of either the outer layer side resin film layer (11) or the metal foil layer (13), the solvent is volatilized, and then the other is applied to the adhesive layer. It is preferable to superimpose the base materials of No. 1 under heating and pressurization, and then aged at room temperature to less than 100 ° C. to cure the adhesive layer. At aging at 100 ° C. or higher, the resin film layer (11) on the outer layer side is thermally shrunk to reduce the elongation at break and the stress at break, which affect the molding, and the curl due to the heat shrinkage reduces the molding productivity. The total amount of the 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) surface of the intermediate laminate.

When the adhesive is applied to the base material, a solvent may be contained within a range that does not affect the base material in the drying step in order to adjust the coating liquid to an appropriate viscosity.
Examples of the solvent include ketone compounds such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, ester compounds such as methyl acetate, ethyl acetate, butyl acetate, ethyl lactate and methoxyethyl acetate, and ether compounds such as diethyl ether and ethylene glycol dimethyl ether. Examples include 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, and water. Be done. These solvents may be used alone or in combination of two or more.

In the present invention, the device for applying the polyurethane adhesive includes a comma coater, a dry laminator, a roll knife coater, a die coater, a roll coater, a bar coater, a gravure roll coater, a reverse roll coater, a blade coater, a gravure coater, and a microgravure. Examples include coaters.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. % In Examples and Comparative Examples all means mass%.

The acid value and hydroxyl value were determined as follows.
<Measurement of acid value (AV)>
Weigh accurately about 1 g of a sample (polyester polyol solution) in an Erlenmeyer flask with a stopper, and add 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution to dissolve it. Phenolphthalein test solution is added to this as an indicator and held for 30 seconds. Then, titrate with 0.1N alcoholic potassium hydroxide solution until the solution turns pink. The acid value was calculated by the following formula (unit: mgKOH / g).
Acid value (mgKOH / g) = (5.611 × a × F) / S
However, S: sample collection amount (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
F: Potency of 0.1N alcoholic potassium hydroxide solution

<Measurement of hydroxyl value (OHV)>
Weigh accurately about 1 g of a sample (polyester polyol solution) in an Erlenmeyer flask with a stopper, and add 100 ml of a toluene / ethanol (volume ratio: toluene / ethanol = 2/1) mixed solution to dissolve it. Further, 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 the mixture was stirred for about 1 hour. Phenolphthalein test solution is added to this as an indicator and lasts for 30 seconds. Then, titrate with 0.1N alcoholic potassium hydroxide solution until the solution turns pink.
The hydroxyl value was calculated by the following formula (unit: mgKOH / g).
Hydroxy group value (mgKOH / g)
= [{(B-a) x F x 28.05} / S] + D
However, S: sample collection amount (g)
a: Consumption of 0.1N alcoholic potassium hydroxide solution (ml)
b: Consumption (ml) of 0.1N alcoholic potassium hydroxide solution in the blank experiment
F: Potency of 0.1N alcoholic potassium hydroxide solution D: Acid value (mgKOH / 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. 5 g (2.2 mol) and 103.7 g (0.88 mol) of 1,6-hexanediol were charged, and the transesterification reaction was carried out at 200 to 230 ° C. for 6 hours. After distilling a predetermined amount of water, tetraisobutyl titanate was added. Add 0.01 g, gradually reduce the pressure, heat at 1.0 to 2.7 hPa, 230 to 250 ° C. for 6 hours, distill off a part of the glycol component, perform a transesterification reaction, and carry out a polyester polyol intermediate. Got
Next, 4.5 g of trimellitic anhydride was added to 300 g of the obtained polyester polyol intermediate, and the mixture was kept at 160 ° C. for 2 hours, and the polyester polyol A-1 having a number average molecular weight of 10,000 and an acid value of 8.1 mg / KOH. Got
Assuming that the excess hydroxyl group component is distilled off almost evenly and the carboxylic acid component and the hydroxyl group component are 100 mol% each, 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%).
Further, this polyester polyol was adjusted to a non-volatile content of 50% with ethyl acetate to obtain a solution of polyol A-1.

(Synthesis Examples 2-5, 7-11)
The carboxylic acid component and the hydroxyl group component were charged so that the product had the composition (mol%) shown in Table 1, and the non-volatile content was 50% in the same manner as in Synthesis Example 1 except that the pressure and time of the transesterification reaction were changed. A solution of polyester polyols A-2 to 5 and 7 to 11 was obtained.

(Synthesis Example 6)
With respect to 500 g of the polyester polyol intermediate obtained in the same manner as in Synthesis Example 1 except that the carboxylic acid component and the hydroxyl group component were charged so as to have the composition shown in Table 1 and the pressure and time of the transesterification reaction were changed. 5 g of isophorone diisocyanate (hereinafter referred to as IPDI) was gradually added and reacted 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 anhydrous trimellitic acid was added and reacted at 160 ° C. for about 2 hours to adjust the non-volatile content to 50% with ethyl acetate to obtain a solution of polyol A-6.

(Synthesis Example 12)
The polyster polyol intermediate in Synthesis Example 1 was adjusted to a non-volatile content of 50% 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, 274. Neopentyl glycol. 5 g (2.6 mol) was charged, an esterification reaction was carried out at 200 to 230 ° C. for 6 hours, a predetermined amount of water was distilled off, 0.01 g of tetraisobutyl titanate was added, and the pressure was gradually reduced to 20 to 130 hPa. The ester exchange reaction was carried out by heating at 230 to 250 ° C. for 3 hours while distilling off a part of the glycol component to obtain an acid value of 1 mg / KOH and a molecular weight of 1500 polyester polyol B-1.
Assuming that the excess hydroxyl group component was distilled off almost evenly and the carboxylic acid component and the hydroxyl group component were 100 mol% each, the composition of the obtained polyester polyol B-1 was as shown in Table 2. Sevacinic acid = 55:45 (mol%), ethylene glycol: neopentyl glycol = 40:60 (mol%).
This polyester polyol was adjusted to a non-volatile content of 50% by mass with ethyl acetate to obtain a solution of polyol solution B-1.

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

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

(Synthesis Example 111)
To 300 g of the polyester polyol B-1 obtained in Synthesis Example 101, 3.6 g of anhydrous trimellitic acid was added and kept at 160 ° C. for 2 hours to adjust the non-volatile content to 50% by mass, and the acid value was 7 mg / KOH. A solution of polyester polyol B-11 was obtained.

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

(Adjustment examples 2-9, 13, 14)
Adduct body (hereinafter referred to as HDI-TMP) in which trimethylolpropane is added to HDI,
IPDI nurate form (hereinafter, IPDI-nurate),
Adduct body (hereinafter referred to as XDI-TMP) in which trimethylolpropane is added to xylylene diisocyanate,
Adduct body (hereinafter, TDI-TMP) in which trimethylolpropane is added to toluene diisocyanate.
An adduct body (hereinafter referred to as MDI-TMP) in which trimethylolpropane is added to diphenylenylmethane diisocyanate is used.
Each was mixed at the ratio shown in Table 3 and diluted with ethyl acetate to obtain a solution of polyisocyanate C-2 to 9, 13 and 14 having a non-volatile content of 50% by mass.

(Adjustment examples 10 to 12)
HDI-biuret, HDI-TMP, and IPDI-TMP were each diluted with ethyl acetate to prepare a solution of polyisocyanates C-10 to C-12 having a non-volatile content of 50% by mass.

(Example 1)
Polyisocyanate A-1 solution with a non-volatile content of 50% by mass: 100 parts by mass, polyisocyanate solution with a non-volatile content of 50% by mass C-1: 10 parts by mass, γ-glycidoxypropyltrimethoxysilane and ethyl acetate as silane coupling agents Was blended in the proportions (parts by mass) shown in Table 4 to obtain an adhesive solution having a non-volatile content of 30% by mass.
After preparing a laminate by the following method using the obtained adhesive solution, the adhesive strength (initial, after the content resistance test) and tearability test were performed on each of the obtained laminates as follows. .. The results are shown in Table 4.

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

(Example 8)
A polyol A-1 solution having a non-volatile content of 50% by mass: 85 parts by mass, a polyol B-1 solution having a non-volatile content of 50% by mass: 15 parts by mass, and a polyisocyanate solution having a non-volatile content of 50% by mass C-1: 17 parts by mass are used. An adhesive solution was obtained in the same manner as in Example 1 according to the composition shown in Table 5, and evaluated in the same manner. The results are also shown in Table 5.

(Examples 9 to 29), (Comparative Examples 4 to 19)
Adhesive solutions were obtained in the same manner as in Example 1 according to the compositions shown in Tables 4 to 7, and evaluated in the same manner. The results are also shown in Tables 4-7.

(Creation of 3-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 prepared by the method described below.
That is, after providing a print layer on the PET film, an adhesive solution is applied to the PET film at room temperature, the solvent is volatilized, and then the coated surface is bonded to the aluminum foil surface to form an intermediate laminate. Got
Further, the adhesive solution is similarly applied to the aluminum foil surface of the intermediate laminate, the solvent is volatilized, and then the coated surface is bonded to the PE film and kept warm at 40 ° C. for 4 days to prepare a three-layer laminate. did.

(Adhesive strength test-initial, after content resistance test)
<Initial>
A test piece having a size of 15 mm × 300 mm was prepared from the three-layer laminate prepared as described above, and the peeling speed was obtained by T-type peeling under the conditions of a temperature of 20 ° C. and a relative humidity of 65% using a tensile tester. The lamination 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 the average values of the five test pieces. The practical range of laminate strength is 4N / 15mm or more.

<After content resistance test>
Using each of the three-layer laminates, a pouch having a size of 9 cm × 13 cm (PE films are located inside each other) was prepared, and ketchup and conditioner were filled as the contents, respectively.
After storing this pouch at 60 ° C. for 2 weeks, the contents were emptied, 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 the laminated strength after the test is 3N / 15 mm or more.

(Preparation of 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 the print layer on the NY film, the adhesive solution was applied onto the print layer at room temperature, the solvent was volatilized, the coated surface was bonded to the PE film, and the temperature was kept at 40 ° C. for 4 days. A laminate was created.

(Tearability test)
A cut was made in the end of the laminated body with a cutter, and the easiness of tearing when torn by hand was evaluated.
(Evaluation criteria)
⊚: Tear without resistance 〇: Tear with some resistance △: PE film has some elongation but somehow tears Δ ×: Clear PE film elongation occurs at the beginning and / or in the middle of tearing.
×: Does not tear at all

Claims (5)

An adhesive containing a polyol component and a polyisocyanate component.
An adhesive that satisfies all of the following conditions (1) to (4) and further satisfies all of the following conditions (5) to (7).
(1) In 100% by mass of the polyol component, 70% by mass or more of the polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained.
(2) The polyester polyol (A) is one of the hydroxyl groups in the reaction product (a1) of the carboxyl group component containing 40 to 90 mol% of the aromatic dibasic acid component in 100 mol% of the carboxyl group component and the hydroxyl group component. A part of the hydroxyl group formed by reacting an acid anhydride with the portion (A1), or a part of the hydroxyl group in the reaction product (a1) and a part of the hydroxyl group in the reaction product (a2) with the diisocyanate. Further, it is obtained by reacting an acid anhydride (A2).
(3) The acid anhydride is at least one of trimellitic acid anhydride and trimellitic acid ester anhydride.
(4) The polyisocyanate component contains two or more kinds of aliphatic polyisocyanate components , and the aliphatic polyisocyanate component is a group consisting of an aliphatic polyisocyanate, an alicyclic polyisocyanate, and an aromatic aliphatic polyisocyanate. Will be selected.
(5) In 100% by mass of the polyol component, 70 to 95% by mass of the polyester polyol (A) having a number average molecular weight of 4000 to 15000 is contained, and 5 to 30 of the polyester polyol (B) having a number average molecular weight of 500 to 3000. Including% by mass,
The polyol component consists only of the polyester polyol (A) and the polyester polyol (B).
(6) The acid value of the polyester polyol (B) is 5 mgKOH / 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 and a hydroxyl group component, or is It is a reaction product (B2) of a part of a hydroxyl group in the reaction product (B1) and a diisocyanate. The aliphatic polyisocyanate component is a nulate of hexamethylene diisocyanate, a burette of hexamethylene diisocyanate, an adduct with trimethylolpropane added to hexamethylene diisocyanate, a nulate of isophorone diisocyanate, a burette of isophorone diisocyanate, and isophorone diisocyanate. 2. The adhesive according to 1. Aliphatic polyisocyanate component
A combination of hexamethylene diisocyanate nurate and hexamethylene diisocyanate burette, hexamethylene diisocyanate burette and isophorone diisocyanate nurate, or an adduct and isophorone diisocyanate with trimethylolpropane added to xylylene diisocyanate. The adhesive according to claim 2, which is one of a combination with an adduct body to which trimethylolpropane is added. A laminate in which the outer layer side resin film layer (11), the adhesive layer, the metal foil layer (13), the inner layer side adhesive layer, and the heat seal layer (14) are arranged in this order.
A laminate in which the adhesive layer is formed by using the adhesive according to any one of claims 1 to 3 . A flexible packaging material using the adhesive according to any one of claims 1 to 3 .