JP2003321664A - Nonsolvent type adhesive composition and application of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a nonsolvent type adhesive composition excellent in coating properties and adhesiveness and useful for materials for packaging foods, medical supplies, cosmetics and the like. <P>SOLUTION: The nonsolvent type adhesive composition comprises a polyester polyol (A) having a high glass transition temperature and a large number average molecular weight, a polyester polyol (B) having a low glass transition temperature and a small number average molecular weight, a three-functional isocyanate compound (C) formed with an alicyclic diisocyanate compound or an aromatic diisocyanate compound, a trifunctional isocyanate compound (D) formed from an aliphatic diisocyanate compound and a polybasic acid anhydride (E). <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solvent-free adhesive composition having excellent adhesiveness, which is useful as a material for food packaging, medical packaging, cosmetic packaging, etc. TECHNICAL FIELD The present invention relates to a sheet with an agent layer, a method for producing the same, a sheet-like laminate of a sheet with an adhesive layer using a solventless adhesive composition and another sheet-like substrate, and a method for producing the same.

[0002]

2. Description of the Related Art As a laminating adhesive for laminating various plastic films with a metal-deposited plastic film or metal foil, there is one that utilizes the reaction between a hydroxyl group and an isocyanate group. That is, a two-component curable organic solvent-based adhesive is used in which a polyisocyanate compound is mixed with an organic solvent solution prepared by dissolving a resin containing a hydroxyl group such as polyester resin or polyether polyurethane resin in an organic solvent. There is. In recent years, there has been a strong tendency toward organic solvent removal of adhesives due to demands for improving the work environment, strengthening the Fire Service Law, and controlling VOC emissions into the atmosphere. is there.

By the way, since the solventless adhesive is solventless, the viscosity of the adhesive must be lowered in order to ensure coatability. In order to reduce the viscosity of the adhesive, the molecular weight of the resin contained in the adhesive has to be smaller than that of the organic solvent type. When the molecular weight of the resin contained in the adhesive is reduced, the adhesiveness is inferior as compared with the organic solvent type adhesive. In particular, it has poor adhesion to a metal-deposited plastic film or metal foil.

[0004]

An object of the present invention is a solventless adhesive composition useful as a material for food packaging, medical packaging, cosmetic packaging, etc., which has excellent coatability and adhesiveness. Another object of the present invention is to provide a solventless adhesive composition that is also excellent. Further, the present invention relates to a sheet with an adhesive layer using the adhesive composition, a method for producing the sheet, and a sheet with an adhesive layer using the solventless adhesive composition and another sheet-like substrate. An object is to provide a laminate and a method for manufacturing the same.

[0005]

That is, the first invention is that the glass transition temperature is 10 to 40 ° C. and the number average molecular weight is 5
0 to 2000 polyester polyol (A) 5 to 5
0% by weight, a glass transition temperature of -70 to 0 ° C, and a number average molecular weight of 500 to 2,000 polyester polyol (B).
95-50% by weight (total of polyester polyols (A) and (B) is 100% by weight), trifunctional isocyanate compound (C) formed from alicyclic diisocyanate compound or aromatic diisocyanate compound,
Trifunctional isocyanate compound (D) formed from an aliphatic diisocyanate compound (provided that the total isocyanate groups in the above trifunctional isocyanate compounds (C) and (D) and the above polyester polyols (A) and (B)) The ratio with the total hydroxyl group is
Hydroxyl group = 0.7 / 1.0 to 1.5 / 1.0), and a polybasic acid anhydride (E) are contained in the solventless adhesive composition.

A second aspect of the present invention has a glass transition temperature of 10 to 4
0 ° C., 5 to 50% by weight of polyester polyol (A) having a number average molecular weight of 500 to 2000, and a glass transition temperature of −
95 to 50% by weight of polyester polyol (B) having a number average molecular weight of 500 to 2000 at 70 to 0 ° C (total of polyester polyols (A) and (B) is 100% by weight) and polybasic acid anhydride (E And a trifunctional isocyanate compound (C) formed from an alicyclic diisocyanate compound or an aromatic diisocyanate compound and a trifunctional isocyanate compound (D) formed from an aliphatic diisocyanate compound. The ratio of the total isocyanate groups in the trifunctional isocyanate compounds (C) and (D) to the total hydroxyl groups in the polyester polyols (A) and (B) is Group / Hydroxyl = 0.7 / 1.0
It is a solventless adhesive composition characterized by being mixed so as to be 1.5 to 1.0.

A third invention is characterized in that the trifunctional isocyanate compound (C) is a trifunctional isocyanate compound (C1) obtained by converting an alicyclic diisocyanate compound or an aromatic diisocyanate compound into an isocyanurate. A solventless adhesive composition according to the first or second invention,

In a fourth aspect of the invention, the trifunctional isocyanate compound (D) is a trifunctional isocyanate compound (D1) obtained by converting an aliphatic diisocyanate compound into an isocyanurate. The solventless adhesive composition according to any one of the inventions.

A fifth aspect of the invention is that the polybasic acid anhydride (E) is
The solventless adhesive composition according to any one of the first to fourth inventions, which is a trimellitic acid ester anhydride represented by the following formula (1) or (2).

[Chemical 3]

[Chemical 4]

A sixth invention is an adhesive obtained by applying the solventless adhesive composition according to any one of the first to fifth inventions to at least one surface of a sheet-like substrate under heating. A seventh aspect of the present invention is a layered sheet, wherein the solventless adhesive composition according to any one of the first to fifth aspects is applied to at least one surface of a sheet-like substrate under heating. The present invention relates to a method for producing a sheet having a characteristic adhesive layer.

An eighth aspect of the present invention is a sheet-shaped laminated body characterized in that the adhesive layer of the sheet with an adhesive layer according to the sixth aspect of the present invention and another sheet-shaped base material are laminated. 9th
The present invention relates to a method for producing a sheet-like laminate, comprising laminating an adhesive layer of the sheet with an adhesive layer according to the sixth aspect of the invention and another sheet-like base material under heating.

A tenth invention is that the solventless adhesive composition according to any one of the first to fifth inventions is applied to at least one surface of a sheet-like substrate under heating to form an adhesive layer. Then, the present invention relates to a method for producing a sheet-like laminate, which comprises laminating another sheet-like base material on the adhesive layer under heating.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A polyester polyol (A) having a glass transition temperature (hereinafter also referred to as Tg) of 10 to 40 ° C. and a number average molecular weight of 500 to 2000, which is used in a solventless adhesive composition of the present invention. , Tg of −70 to 0 ° C. and number average molecular weight of 500 to 2000 will be described. Hereinafter, the polyester polyol (A) is referred to as a high Tg polyester polyol (A),
The polyester polyol (B) may be referred to as a low Tg polyester polyol (B). In the present invention, it is important to use both in combination, and 5 to 50% by weight of the high Tg polyester polyol (A) is contained in 100% by weight of the total amount of the high Tg polyester polyol (A) and the low Tg polyester polyol (B). It is especially important to include.

The high Tg polyester polyol (A) is
If it is less than 5% by weight, sufficient adhesive performance cannot be obtained. On the other hand, the high Tg polyester polyol (A) is 5
If it is more than 0% by weight, the Tg of the high Tg polyester polyol (A) exceeds 40 ° C., or the number average molecular weight exceeds 2000, after blending the trifunctional isocyanate compounds (C), (D), etc. , The viscosity of the adhesive composition exceeds 3000 mPa even when heated to about 70 ° C.,
The coatability is impaired. Further, when the Tg of the high Tg polyester polyol (A) is less than 10 ° C. or the number average molecular weight is less than 500, even if a plastic film and a metal foil are bonded using the adhesive composition obtained, Sufficient adhesion performance cannot be obtained. The Tg of the high Tg polyester polyol (A) is preferably 20 to 30 ° C.

Low Tg Polyester Polyol (B) T
When g exceeds 0 ° C. or the number average molecular weight exceeds 2000, a trifunctional isocyanate compound (C),
The viscosity of the adhesive composition exceeds 3000 mPa even if it is heated to about 70 ° C. after blending (D) and the like, and the coatability is impaired. On the other hand, the Tg of the low Tg polyester polyol (B) is less than -70 ° C, or the number average molecular weight is 500.
If it is less than the above range, sufficient adhesive performance cannot be obtained even if the plastic film and the metal foil are bonded using the adhesive composition obtained. The Tg of the low Tg polyester polyol (B) is preferably -60 to -30 ° C.

The polyester polyol (A) or (B) of the present invention is a polyester obtained by reacting a dibasic acid or a dialkyl ester thereof and a polybasic acid anhydride or a mixture thereof with a polyhydric alcohol. Polyol, polycaprolactone, polyvalerolactone, poly (β-methyl-γ-valerolactone)
Polyester polyols obtained by ring-opening polymerization of lactones such as can be used.

Examples of the dibasic acid or dialkyl ester thereof include dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid and itaconic acid, and dialkyl esters thereof.

Examples of polybasic acid anhydrides include trimetic anhydride, methylcyclohexene tricarboxylic anhydride, pyromellitic dianhydride, and the like.

The polyhydric alcohols used are ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, diethylene glycol, butylene glycol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,
5-pentanediol, butylethylpropylene glycol, 1,9-nonanediol, 1,10-decanediol, 3,3'-dimethylolheptane, triethylene glycol, polyoxyethylene glycol, polyoxypropylene glycol, ethylene oxide Examples thereof include copolymers of propylene oxide, glycols such as polytetramethylene ether glycol, trihydric alcohols such as glycerin, trimethylolethane and trimethylolpropane, and tetrahydric alcohols such as pentaerythritol and dipentaerythritol. In addition, an alcohol derivative of rosin (for example, KE-60 manufactured by Arakawa Chemical Co., Ltd.)
1) or an allyl alcohol copolymer of cyclopentadiene (for example, Quinton 1700 manufactured by Nippon Zeon Co., Ltd.)
Etc. can be mentioned.

By the way, the solventless adhesive composition of the present invention contains a polyester polyol (A), as described below.
(B) and trifunctional isocyanate compound (C), (D)
And the like are mixed under heating and then applied to the sheet-shaped substrate in a softened or molten state. If the reaction between the polyester polyols (A) and (B) and the trifunctional isocyanate compounds (C) and (D) proceeds during coating, the viscosity becomes high and the coating itself is hindered. . Therefore, it is preferable that the polyester polyols (A) and (B) do not react with the trifunctional isocyanate compounds (C) and (D) as much as possible during coating.

An esterification catalyst can be used when synthesizing the polyester polyols (A) and (B).
However, the esterification catalyst may serve as a reaction catalyst for the hydroxyl groups in the polyester polyols (A) and (B) and the isocyanate groups in the trifunctional isocyanate compounds (C) and (D). Therefore, when the adhesive composition is applied to the sheet-shaped substrate, the polyester polyol (A),
(B) and trifunctional isocyanate compound (C), (D)
It is preferable not to use such an esterification catalyst at the time of synthesizing the polyester polyols (A) and (B) in order to prevent the reaction between and as much as possible.

Further, polyester polyol (A),
When a carboxyl group remains in (B), this carboxyl group serves as a reaction catalyst for the polyester polyols (A) and (B) and the trifunctional isocyanate compounds (C) and (D). Therefore, for the same reason as above, the smaller the amount of carboxyl groups in the polyester polyols (A) and (B), the better. The amount of this carboxyl group can be represented by an acid value. Polyester polyol (A), (B)
The acid value of is preferably 5 (mgKOH / g) or less, more preferably 2.5 (mgKOH / g) or less, and even more preferably 1
(MgKOH / g) or less.

Next, two types of 3 used in the present invention
The functional isocyanate compounds (C) and (D) will be described. The isocyanate compounds (C) and (D) are the above-mentioned polyester polyols (A) and (B) as described later.
Etc., and then coated on a sheet-shaped substrate, and by laminating another sheet-shaped substrate under heating, it reacts with the polyester polyols (A) and (B), and an adhesive agent is applied between both sheet-shaped substrates. Form the layers. Isocyanate compound (C),
(D) is a trifunctional isocyanate compound, and is formed from a diisocyanate compound. Each of these has a specific structure as shown below, and the present invention is characterized by using both of them in combination.

As the diisocyanate compound, various known various diisocyanates of alicyclic group, aromatic group and aliphatic group can be mentioned. For example, as the alicyclic diisocyanate, cyclohexane-1,4-diisocyanate,
Isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, etc.

As the aromatic diisocyanate, 1,5
-Naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1, 4-phenylene diisocyanate, tolylene diisocyanate, xylylene diisocyanate, etc.

Examples of the aliphatic diisocyanate include butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate and m-tetramethylxylylene diisocyanate. , Lysine diisocyanate, and dimerisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group.

From the above-mentioned diisocyanate compound, the following trifunctional or higher functional isocyanate compounds of adducts, isocyanurates, and burettes can be obtained.

The adduct is obtained by reacting various known various diisocyanate compounds with trihydric or higher alcohols. The case of trifunctional alcohol is shown below.

[0029]

[Chemical 5]

Examples of trihydric or higher alcohols used for adducts include glycerin, trimethylolpropane,
Examples include trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaethritol and the like.

The isocyanurate compound has various known diisocyanate compounds 3 as shown in the following formula.
It consists of molecules.

[0032]

[Chemical 6]

The burette body is obtained by reacting various known various diisocyanate compounds with water, as shown in the following formula.

[0034]

[Chemical 7]

The trifunctional isocyanate compound (C) is
A diisocyanate compound having a cyclic structure, that is, an adduct body, an isocyanurate body, or a burette body formed from an alicyclic or aromatic diisocyanate compound is preferable, and an isocyanurate body is preferable.
Particularly, an isocyanurate body of isophorone diisocyanate is preferable.

The trifunctional isocyanate compound (D) is
A diisocyanate compound having no cyclic structure, that is, an adduct body formed from an aliphatic diisocyanate compound, an isocyanurate body or a buret body,
It is preferably an isocyanurate body or a buret body. Particularly, an isocyanurate body or burette body of 1,6-hexamethylene diisocyanate is preferable, and a burette body of 1,6-hexamethylene diisocyanate is most preferable.

In the present invention, it is important to use the trifunctional isocyanate compounds (C) and (D) together.
That is, the trifunctional isocyanate compound (C) has a larger viscosity when melted than the trifunctional isocyanate compound (D) because of its ring structure. Therefore, when only the trifunctional isocyanate compound (C) having a ring structure is used, the viscosity of the adhesive composition at the time of melting becomes large and it becomes difficult to apply. If only the trifunctional isocyanate compound (D) is used, sufficient adhesion performance cannot be obtained. Therefore, it is important to balance the viscosity of the adhesive composition at the time of melting and the adhesive performance by using both in combination.

Further, in the present invention, in addition to the above-mentioned trifunctional isocyanate compounds (C) and (D), triphenylmethane-4,4 ′, 4 ″ -triisocyanate and 1,3,5-triisocyanate are used. Isocyanatobenzene, 2,4
Isocyanate compounds having three or more isocyanate groups such as 6-triisocyanatotoluene and 4,4′-dimethyldiphenylmethane-2,2 ′, 5,5 ″ -tetraisocyanate can also be used.

It is important that the adhesive composition of the present invention contains a polybasic acid anhydride (E). By containing the polybasic acid anhydride (E), the adhesiveness between aluminum and the plastic film can be secured. In the present invention,
As the polybasic acid anhydride (E), for example, phthalic anhydride, trimellitic anhydride, pyromellitic dianhydride, which is an anhydride of polybasic acid such as phthalic acid, trimellitic acid, or pyromellitic acid, is used. You can

Among these anhydrides, trimellitic acid ester anhydride is particularly preferable. Examples of the trimellitic acid ester anhydride include ethylene glycol bisanhydrotrimellitate represented by the following formula (1) and glycerol trisanhydrotrimellitate represented by the following formula (2). More preferred is ethylene glycol bisanhydrotrimellitate represented by the formula (1).

These anhydrides were obtained from Shin Nippon Rika Co., Ltd. using RIKACID TMA-X (where X is C or 10,
And 15), RIKACID TMEG-X (where X is 10
0,200,500,600).

[0042]

[Chemical 8]

[0043]

[Chemical 9]

As the polybasic acid anhydride (E), it is also possible to use abietic acid as a rosin component, a petroleum resin, or a derivative obtained by addition reaction of maleic anhydride with a mixture thereof.

The solventless adhesive composition of the present invention can be obtained, for example, by various methods as described below, (3)
Is preferred. (1) Polyester polyols (A), (B), trifunctional isocyanate compounds (C), (D) and polybasic acid anhydride (E) are mixed. (2) A polyester polyol (A), (B) and a polybasic acid anhydride (E) are mixed to obtain a first component, and then the first component is mixed with a trifunctional isocyanate compound (C) and (D). ) Are mixed. (3) A first component obtained by mixing the polyester polyols (A), (B) and the polybasic acid anhydride (E) is obtained, and a mixture of the trifunctional isocyanate compounds (C) and (D) (second 2 components) and then both components are mixed. still,
In the case of the methods (2) and (3), before the trifunctional isocyanate compounds (C) and (D) are mixed or the second component is mixed, the polyester polyol (A ), Part of the hydroxyl groups of (B) and polybasic acid anhydride (E)
May be partially or wholly reacted.

In the adhesive composition of the present invention, the ratio of the total isocyanate groups in the trifunctional isocyanate compounds (C) and (D) to the total hydroxyl groups in the polyester polyols (A) and (B) is: Isocyanate group / hydroxyl group = 0.
It is 7 / 1.0 to 2.0 / 1.0, preferably 0.7 / 1.0 to 1.5 / 1.0. When the number of isocyanate groups is relatively small compared to the number of hydroxyl groups, it causes curing failure. On the other hand, if the number of isocyanate groups is relatively large compared to the number of hydroxyl groups, the reaction between hydroxyl groups and isocyanate groups proceeds too much after mixing and before or during coating, which makes coating itself difficult.
Further, when the number of the isocyanate groups is relatively too large, the adhesive composition becomes expensive, which is economically disadvantageous. further,
It is not good for hygiene.

In the adhesive composition of the present invention, the polybasic acid anhydride (E) is used in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the polyester polyols (A) and (B) in total. it can. If the polybasic acid anhydride (E) used is less than 0.1 parts by weight, sufficient adhesive force cannot be obtained. On the other hand, if more than 2 parts by weight is used, when the polyester polyol of the present invention and the isocyanate compound are mixed, the reaction is accelerated and the viscosity is remarkably increased, which is not preferable in terms of work. In addition, there is a cost disadvantage. Polybasic acid anhydride (E)
Can be used preferably in the range of 0.2 to 1 part by weight.

An adhesion promoter may also be used in the solventless adhesive composition of the present invention. Adhesion promoters include
Silane coupling agent, titanate coupling agent,
Examples include aluminum-based coupling agents and epoxy resins.

As the silane coupling agent, for example,
γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, N-β (aminoethyl)-
Aminosilanes such as γ-aminopropyltrimethoxysilane, N-β (aminoethyl) -γ-aminopropyltrimethyldimethoxysilane and N-phenyl-γ-aminopropyltrimethoxysilane; β- (3,4-epoxycyclohexyl) ethyl Epoxy silanes such as trimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane; vinyltris (β-methoxyethoxy) silane, vinyltriethoxysilane, vinyltrimethoxysilane, γ-methacrylic acid Vinylsilane such as roxypropyltrimethoxysilane; hexamethyldisilazane, γ-mercaptopropyltrimethoxysilane and the like can be mentioned.

Examples of the titanate coupling agent include tetraisopropoxy titanium, tetra-n-butoxy titanium, butyl titanate dimer, tetrastearyl titanate, titanium acetylacetonate, titanium lactate, tetraoctylene glycol titanate, and the like.
Examples thereof include titanium lactate and tetrastearoxytitanium.

Examples of the aluminum coupling agent include acetoalkoxyaluminum diisopropylate.

As the epoxy resin, generally commercially available EP-bis type, novolak type, β-methyl epichloro type, cyclic oxirane type, glycidyl ether type, glycidyl ester type, polyglycol ether type, glycol ether type, epoxidized fatty acid ester are used. Examples thereof include various epoxy resins such as epoxy resins, polycarboxylic acid ester resins, aminoglycidyl resins, and resorcin resins.

The solventless adhesive composition of the present invention comprises a filler, a softening agent, an antiaging agent, a stabilizer, an adhesion promoter, a leveling agent, a defoaming agent, a plasticizer, an inorganic filler, in addition to the above components.
Tackifying resin, fibers, usable time extender, antioxidant, ultraviolet absorber, hydrolysis inhibitor, antifungal agent, thickener,
A plasticizer, a colorant such as a pigment, and an additive such as a filler can be used as necessary. Further, known catalysts, additives and the like can be used for controlling the curing reaction.

Next, a sheet with an adhesive layer using the above solventless adhesive composition and a method for producing the same will be described. A solventless adhesive composition containing a polyester polyol (A), (B), a trifunctional isocyanate compound (C), (D) and a polybasic acid anhydride (E) is obtained, and the adhesive composition is heated. The sheet with the adhesive layer of the present invention can be formed by applying various kinds of sheet-shaped substrates to one surface of the sheet.

For coating the solvent-free adhesive composition on the sheet-shaped substrate, conventionally known methods can be widely used. For example, a film split method using a rubber roll or a metal roll may be used. In this method, the amount of adhesive applied is adjusted by the nip pressure of the coating roll and the peripheral speed difference.

The adhesive layer of the obtained sheet with an adhesive layer must not have completed the reaction between the polyester polyols (A) and (B) and the trifunctional isocyanate compounds (C) and (D). When the reaction is completed at this stage,
Since another sheet-shaped substrate cannot be laminated in the next step, the reaction may partially proceed, but the reaction must not be completed. The coating film thickness is preferably 0.1 to 10 μm, and the coating amount is preferably 0.1 to 5 g / m ² .

Considering the workability at the time of application and the viscosity of the solventless adhesive composition under heating, it is usually from room temperature to 120.
It is preferable to heat the solventless adhesive composition to a temperature of 40 ° C., preferably 40 to 100 ° C. In addition, the solventless adhesive composition of the present invention is a polyester polyol (A), (B), a trifunctional isocyanate compound (C), (D) and a polybasic acid anhydride ( After mixing E), the viscosity under heating after lapse of 30 minutes is 20000.
It is preferably mPa or less, more preferably the viscosity under heating even after 60 minutes is 20000 mPa or less, and further preferably the viscosity after 60 minutes is 10,000 mPa or less.

Examples of the material of the above-mentioned sheet-shaped substrate include metal foils, papers, cellophane, proteins such as collagen, polysaccharides such as pullulan, polyolefins, polyvinyl chlorides, polyvinylidene chlorides, Polystyrenes, polyvinyl alcohols, polyacrylonitriles, fluoropolymers, polyesters, polyamides,
Polyurethanes, polysulfones, polyetherimides and the like can be mentioned. In the present invention, a non-stretched sheet-shaped substrate or a stretched sheet-shaped substrate formed of these materials is used as the sheet-shaped substrate. Further, in the present invention, a composite sheet-shaped substrate formed by laminating a plurality of sheet-shaped substrates formed of the above-mentioned various materials can also be used.

The metal foils include aluminum foil, iron foil, lead foil, tin foil, etc., and the papers include pure white paper, high-quality paper, coated paper, kraft paper, paperboard, rayon paper, mixed paper, non-woven paper, etc. Examples of cellophane include ordinary cellophane, moisture-proof cellophane (lacquer coat, polymer coat, polyethylene coat) and the like.

The polyolefins include non-polar polyolefins and polar polyolefins. The non-polar polyolefins include low density polyethylene, medium density polyethylene, high density polyethylene, ethylene / vinyl acetate copolymer, chlorinated polyethylene. , Polypropylene, propylene / ethylene random copolymer, propylene / ethylene block copolymer, propylene / butene copolymer, propylene / ethylene / butene copolymer, polybutene-1,2-polybutadiene, etc. , Ethylene / methyl acrylate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ionomer and the like.

As polyvinyl chloride, non-plasticized polyvinyl chloride, rigid polyvinyl chloride, semi-rigid polyvinyl chloride,
Soft polyvinyl chloride and the like, and as polyvinylidene chloride, vinylidene chloride / acrylonitrile copolymer, vinylidene chloride / vinyl chloride copolymer, vinylidene chloride / methacrylic acid copolymer, etc.

As the polystyrenes, polystyrene,
Styrene / acrylonitrile copolymers, acrylonitrile / butadiene / styrene copolymers, etc., polyvinyl alcohols include unplasticized polyvinyl alcohol, plasticized polyvinyl alcohol, saponified ethylene / vinyl acetate copolymers, etc., and polyacrylonitriles , Acrylonitrile / methyl acrylate copolymer and the like, as the fluororesin, tetrafluoroethylene-6-fluoropropylene copolymer, trifluoride / ethylene chloride copolymer, etc.

Polyesters include polyethylene terephthalate and 1,4-cyclohexylene dimethylene terephthalate / isophthalate, polycarbonates include polycarbonate and polyphthalate carbonate, and polyamides include nylon-6 and nylon-6. / 6, a metaxylylene diamine amide copolymer, etc. are mentioned.

Metal foils, polyolefins and polyesters are preferable, aluminum is preferable as the metal foil, polypropylene is preferable as the polyolefins, and polyethylene terephthalate is preferable as the polyesters.

Next, a sheet-like laminated body using the above-mentioned sheet with an adhesive layer will be described. As described above, in the adhesive layer of the sheet with the adhesive layer, the reaction between the hydroxyl group and the isocyanate group, or the hydroxyl group and the polybasic acid anhydride is not completed. Then, another sheet-shaped substrate is brought into contact with this adhesive layer, and the reaction of the adhesive layer between both sheet-shaped substrates is allowed to proceed in that state to obtain a sheet-shaped laminate. When another sheet-shaped substrate is brought into contact with the adhesive layer, it is preferable to bring it into contact with heating, and further it is preferable to bring it into contact with pressure. Specifically, it is preferable to use a nip roll. Furthermore, it is desirable that the sheet-shaped laminate be aged at 30 to 50 ° C. to accelerate crosslinking.

[0066]

EXAMPLES The present invention will now be specifically described with reference to examples, but these do not limit the present invention. The number average molecular weight of the polyester polyol was determined by gel permeation chromatography (GPC) and calculated as a standard polystyrene conversion value. The glass transition temperature (hereinafter sometimes referred to as Tg) of polyester polyol is
It was determined by differential scanning calorimetry (DSC) under atmospheric conditions. A B-type viscometer was used for the viscosity measurement after blending the polyester polyol and the polyisocyanate compound.

Synthesis Example 1 438 parts of isophthalic acid, 106 parts of ethylene glycol, neopentyl glycol
179 parts were charged into a reaction vessel and heated to 150 ° C. to 240 ° C. with stirring under a nitrogen gas stream to carry out an esterification reaction. When the acid value reaches 1.3, the reaction temperature is increased to 20.
The temperature was lowered to 0 ° C, the pressure in the reaction vessel was gradually reduced, and the reaction was performed at 10 mmHg or less for 30 minutes to obtain an acid value of 0.4 and a number average molecular weight of about 80.
A polyester polyol resin having a hydroxyl group at both ends and having a Tg of about 27 ° C. was obtained. Hereinafter, this resin is described as polyester polyol A-1.

(Synthesis Example 2) Isophthalic acid 415 parts, ethylene glycol 109 parts, neopentyl glycol
182 parts were charged into a reaction vessel and heated to 150 ° C. to 240 ° C. with stirring under a nitrogen gas stream to carry out an esterification reaction. When the acid value reaches 1.3, the reaction temperature is increased to 20.
The temperature was lowered to 0 ° C., the pressure in the reaction vessel was gradually reduced, and the reaction was performed at 10 mmHg or less for 30 minutes to obtain an acid value of 0.5 and a number average molecular weight of about 60.
A polyester polyol resin having hydroxyl groups at both ends having a Tg of about 16 ° C. was obtained. Hereinafter, this resin is described as polyester polyol A-2.

(Synthesis Example 3) 310 parts of cis-1,4-cyclohexanedicarboxylic acid and 415 parts of 1,4-cyclohexanedimethanol were charged into a reaction vessel and heated to 150 ° C to 220 ° C with stirring under a nitrogen gas stream. Then, the esterification reaction was carried out. When the acid value reached 3.0, the reaction temperature was lowered to 200 ° C, and the pressure in the reaction vessel was gradually reduced to 10 m.
The reaction was carried out at mHg or less for 30 minutes to obtain a polyester polyol resin having an acid value of 2.0, a number average molecular weight of about 390 and a Tg of 32 ° C. and having hydroxyl groups at both ends. Hereinafter, this resin is described as polyester polyol A-3.

(Synthesis Example 4) 187 parts of isophthalic acid, 278 parts of sebacic acid, 56 parts of ethylene glycol and 283 parts of neopentyl glycol were charged into a reaction vessel and heated to 150 ° C to 240 ° C with stirring under a nitrogen gas stream. The esterification reaction was carried out. When the acid value reached 0.5, the reaction temperature was lowered to 200 ° C., the pressure in the reaction vessel was gradually reduced, and the reaction was performed at 10 mmHg or less for 30 minutes to obtain an acid value of 0.0
6, a polyester polyol resin having a number average molecular weight of about 1000 and a Tg of about -50 ° C and having hydroxyl groups at both ends was obtained.
Hereinafter, this resin is described as polyester polyol B-1.

(Synthesis example 5) Polyester polyol B
-1 to 100 parts, isophorone diisocyanate (hereinafter,
1.5 parts (sometimes abbreviated as IPDI) are charged into a reaction vessel and heated to 90 ° C. to 100 ° C. with stirring under a nitrogen gas stream, and urethanization reaction is carried out until absorption of isocyanate disappears by infrared spectroscopic analysis. The number average molecular weight of about 10
A polyester polyol resin having a hydroxyl group of 50 and Tg of about -50 ° C at both ends was obtained. Hereinafter, this resin is described as polyester polyol B-2.

(Synthesis Example 6) 224 parts of isophthalic acid, 333 parts of sebacic acid, 51 parts of ethylene glycol, and 257 parts of neopentyl glycol were placed in a reaction vessel and heated to 150 ° C to 240 ° C with stirring under a nitrogen gas stream. The esterification reaction was carried out. When the acid value reached 3.1, the reaction temperature was lowered to 200 ° C., the pressure in the reaction vessel was gradually reduced, and the reaction was performed at 10 mmHg or less for 30 minutes to obtain an acid value of 2.
A polyester polyol resin having 0, a number average molecular weight of about 6000 and a Tg of -28 ° C and having hydroxyl groups at both ends was obtained. Hereinafter, this resin is described as polyester polyol B-3.

(Synthesis Example 7) cis-1,4-cyclohexanedicarboxylic acid 344 parts, propylene glycol 304
A part was placed in a reaction vessel and heated to 150 ° C. to 220 ° C. with stirring under a nitrogen gas stream to carry out an esterification reaction. When the acid value reaches 0.6, the reaction temperature is 200 ° C.
And gradually depressurize the reaction vessel to react for 10 minutes at 10 mmHg or less, acid value 0.3, number average molecular weight about 450,
A polyester polyol resin having Tg of -26 ° C and having hydroxyl groups at both ends was obtained. Hereinafter, this resin is described as polyester polyol B-4.

(Synthesis Example 8) VE manufactured by Degussa Japan Co., Ltd.
STANATT1890 / 100 (IPDI isocyanurate body) 70 parts and Sumika Bayer Urethane Co., Ltd. Sumidure N3200 (1,6-hexamethylene diisocyanate (hereinafter, abbreviated as HDI) biuret body) 30 parts Was charged into a reaction vessel and heated at 100 ° C. to 120 ° C. for 30 to 60 minutes while stirring under a nitrogen gas stream to dissolve. This was used as the polyisocyanate compound in the examples.

(Example 1) Polyester polyol A-
1, 10 parts of polyester polyol B-1 90 parts,
And a silane coupling agent (γ-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd.))
5 parts were charged into a reaction vessel and heated at 50 ° C. to 70 ° C. for 30 to 60 minutes with stirring under a nitrogen gas stream to dissolve. Then, 0.25 part of ethylene glycol bisanhydrotrimellitate was added and dissolved by stirring at 100 ° C. to 120 ° C. for 40 minutes. Then, 50 parts of the polyisocyanate compound prepared in Synthesis Example 8 (isophorone diisocyanate isocyanurate body: 35 parts, hexamethylene diisocyanate burette body: 15 parts) are mixed by heating at about 80 ° C. A mold adhesive composition was obtained. The solventless adhesive composition was evaluated by the method described below.

A mixture of polyester polyol and ethylene glycol bisanhydrotrimellitate was preheated to 70 ° C., and a polyisocyanate compound preheated to 70 ° C. was added to the mixture. Was measured and found to be 3000 mPa or less. (Indicated as O in the row of viscosity at 70 ° C. in Table 1).

(Examples 2 to 6) Solventless adhesive compositions were obtained in the same manner as in Example 1 at the ratios (weight ratios) shown in Table 1 and evaluated in the same manner.

Comparative Examples 1 to 12 Solventless adhesive compositions were obtained in the same manner as in Example 1 in the proportions (weight ratios) shown in Table 2 and evaluated in the same manner. Incidentally, Comparative Example 10 uses VESTANATT 1890/100 (isocyanurate of isophorone diisocyanate) manufactured by Degussa Japan Co., Ltd., and Comparative Example 11 uses Sumidure N3200 (1,6- Hexamethylene diisocyanate biuret) was used alone.

(Preparation of Sheet-like Laminate) Polyethylene terephthalate (hereinafter sometimes referred to as PET) / aluminum foil (9 micrometers) / unstretched polypropylene (hereinafter sometimes referred to as CPP, 70 micrometers) A composite film was made by the following method. That is, the adhesive compositions obtained in the respective Examples and Comparative Examples were heated and mixed at about 80 ° C., and coated on CPP with a solventless test coater at a coating amount of 1.5.
After coating so as to be g / m ² , the coated surface is laminated with aluminum, and aluminum / CPP is laminated. Separately coated on PET at a coating amount of 1.5 g / m ² , laminate the coated surface with the aluminum surface of the above aluminum / CPP, and then add PET / aluminum /
It has a CPP configuration. This was stored in a constant temperature bath at 50 ° C. for 3 days to prepare a sheet-shaped laminate. If the viscosity of the solvent-free adhesive composition at 70 ° C. exceeded 3000 mPa, the coating itself was difficult, and thus a sheet-shaped laminate was not prepared.

(Adhesion test before retort) The sheet-shaped laminate produced by the above method was cut into 300 mm × 15 mm,
It was a test piece. Using an Instron type tensile tester and peeling speed of 300 mm / min, for each test piece, between PET / aluminum and aluminum / CP
The T-type peel strength between P (g / 15 mm, 5 point average) was measured.

<Retort resistance> (Visual evaluation) Using each sheet-shaped laminate, a pouch (bag) having a size of 9 cm × 12 cm was prepared so that the CPP was on the inside, and 20 g of water was filled therein. did. Using a rotary retort tester, 30 r. p. m. , 120 ° C, 30
After performing hot water sterilization for each pouch under pressure of P,
The peeled state between the ET film and the aluminum foil was visually observed.
○ indicates no peeling △ indicates partial peeling

(Adhesion test after retort) After visual observation,
The pouch is cut to obtain a 300 mm × 15 mm test piece, and the T-type peel strength (g / 15 mm, 5 point average) between PET / aluminum and aluminum / CPP is measured on the test piece in the same manner as before retort. did.

[0083]

[Table 1]

From the results shown in Table 1, it is understood that the solventless adhesive composition of the present invention is excellent as an adhesive for a composite laminate film for producing a packaging material for retort foods.

[0085]

The composition of the present invention exhibits extremely excellent adhesive strength and hot water resistance between a metal foil such as aluminum and a plastic film such as polyethylene terephthalate, polypropylene, polyester, nylon or polyethylene. 120 ° C with the material filled with water
Even if the lower retort sterilization treatment is performed, the metal foil and the plastic film are not separated from each other, and a packaging material having good long-term storage stability of food can be obtained.

Continued front page    F-term (reference) 4F100 AK51G AT00A BA02 CB02B                       GB15 GB23 GB66                 4J004 AA14 AA17 AB05 CA02 CA03                       CA04 CA06 CA08 CB02 FA06                       FA08 GA01                 4J034 BA07 DB04 DC50 DF01 DF11                       DF12 DF14 HA08 HC12 HC13                       HC17 HC22 HC46 HC52 HC61                       HC64 HC67 HC71 LA16 LA33                       QA03 RA08                 4J040 EF111 EF291 EF301 EF311                       EF321 HB34 JA09 LA01                       LA02 MA02 MA10 NA06

Claims (10)

[Claims] 1. A polyester polyol (A) having a glass transition temperature of 10 to 40 ° C., a number average molecular weight of 500 to 2000, and a glass transition temperature of −70 to 0.
C., 95 to 50% by weight of polyester polyol (B) having a number average molecular weight of 500 to 2000 (total of polyester polyol (A) and (B) is 100% by weight), alicyclic diisocyanate compound or aromatic diisocyanate compound A trifunctional isocyanate compound (C) formed from a trifunctional isocyanate compound (D) formed from an aliphatic diisocyanate compound (provided that the above trifunctional isocyanate compounds (C) and (D) are the total isocyanates). The ratio of the groups to the total hydroxyl groups in the polyester polyols (A) and (B) is such that isocyanate groups / hydroxyl groups = 0.7 / 1.0 to 1.5 / 1.0) and polybasic acid anhydride (E) are contained. A solventless adhesive composition characterized. 2. A polyester polyol (A) having a glass transition temperature of 10 to 40 ° C., a number average molecular weight of 500 to 2000, and a glass transition temperature of −70 to 0.
Containing 95 to 50% by weight of polyester polyol (B) having a number average molecular weight of 500 to 2000 (the total of polyester polyols (A) and (B) is 100% by weight) and polybasic acid anhydride (E). And a trifunctional isocyanate compound (C) formed of an alicyclic diisocyanate compound or an aromatic diisocyanate compound and a trifunctional isocyanate compound (D) formed of an aliphatic diisocyanate compound. The ratio of the total isocyanate groups in the above trifunctional isocyanate compounds (C) and (D) to the total hydroxyl groups in the above polyester polyols (A) and (B) is the isocyanate group / hydroxyl group. = 0.7 / 1.0 to 1.5 / 1.0. A solventless adhesive composition characterized by being blended so as to be 0.7 / 1.0 to 1.5 / 1.0. 3. A trifunctional isocyanate compound (C)
Is obtained by converting an alicyclic diisocyanate compound or an aromatic diisocyanate compound into an isocyanurate body 3
The solventless adhesive composition according to claim 1 or 2, which is a functional isocyanate compound (C1). 4. A trifunctional isocyanate compound (D)
Is a trifunctional isocyanate compound (D1) obtained by converting an aliphatic diisocyanate compound into a burette form, and the solventless adhesive composition according to any one of claims 1 to 3. 5. The polybasic acid anhydride (E) has the following formula (1):
Alternatively, the solvent-free adhesive composition according to any one of claims 1 to 4, which is a trimellitic acid ester anhydride represented by (2). [Chemical 1] [Chemical 2] 6. A sheet with an adhesive layer obtained by applying the solventless adhesive composition according to any one of claims 1 to 5 to at least one surface of a sheet-shaped substrate under heating. 7. A sheet with an adhesive layer, characterized in that the solventless adhesive composition according to any one of claims 1 to 5 is applied to at least one surface of a sheet-like substrate under heating. Method. 8. A sheet-shaped laminate, comprising the adhesive layer of the sheet with an adhesive layer according to claim 6 and another sheet-shaped base material laminated together. 9. A method for producing a sheet-like laminate, comprising laminating an adhesive layer of the sheet with an adhesive layer according to claim 6 and another sheet-like base material under heating. 10. The solventless adhesive composition according to claim 1 is applied to at least one surface of a sheet-like base material under heating to form an adhesive layer, and the adhesive layer is formed on the adhesive layer. A method for producing a sheet-like laminate, comprising laminating another sheet-like substrate under heating.