TW201430086A - Adhesive composition, and laminate and method for manufacturing the same - Google Patents

Abstract

The invention provides an adhesive composition, which can age in less time than before and show equal to or greater adhesive performance, even though environmental humanity is not strictly managed to low humidity, and has a long pot life. The adhesive composition of the invention includes a polyisocyanate component (A) and a polyol component (B). The polyisocyanate component (A) is a reactive product formed by reacting 2, 4'-diphenylmethane diisocyanate (a1) and 4, 4'-diphenylmethane diisocyanate (a2) with a polyol, which must include a polyether polyol, under a condition of excess isocyanate groups. The polyol component (B) must include a polyester diol (b1), which has a number average molecular weight (Mn) equal to or above 500 and equal to or below 3000, and at least one of a diol (b2) and a triol (b3), which has Mn equal to or above 50 and less than 500.

Description

Substrate composition, laminated body and method of producing the same

This invention relates to an adhesive composition. Further, it relates to a laminate using the above-described adhesive composition and a method for producing the same.

The bonding of various plastic films or the bonding of a plastic film to a metal deposition film or a metal foil has been conventionally carried out by a dry lamination method using a hydroxy/isocyanate solvent-based adhesive. However, since the dry lamination method uses an adhesive containing an organic solvent, it is necessary to prevent or prevent environmental pollution or fire.

In recent years, there has been a demand for de-solventization of an adhesive agent due to demand for a simple device, and research on solventlessness has been actively conducted.

For example, Patent Document 1 discloses a solvent-free laminate for an adhesive layer comprising a polyol component (1) and a polyisocyanate component (2) containing two kinds of polyisocyanate compounds.

Further, Patent Document 2 discloses a polyisocyanate component (2) containing a polyol component (1) and a trifunctional polyisocyanate compound, a divergence point concentration in a specific range, and a hydroxyl group number: isocyanate group number of moles = A solvent-free laminate adhesive composition of 1:1 to 1:3.

Patent Document 3 discloses a solventless adhesive composition containing a polyol component (A) and an isocyanate component (B) which must have isophorone diisocyanate.

Patent Document 4 discloses a solventless adhesive composition comprising a polyol component (A), a polyisocyanate compound (B), and a compound (C) having a specific particle diameter.

Further, Patent Document 5 discloses that the polyisocyanate component (a) and the polyol component (b) are contained, and the polyisocyanate component (a) contains a single system of 4,4'-methylene diphenyl diisocyanate (i). And an adhesive composition of the isocyanate functional prepolymer (ii). The isocyanate functional prepolymer (ii) is a reaction product containing a single system of 4,4'-methylene diphenyl diisocyanate and a prepolymer reaction material mixture of one or more kinds of polyols, and more than one type A polyol, designated to contain a triol having an average molecular weight in a particular range.

[Prior Art Literature]

[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. Hei 8-60131

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2003-96428

[Patent Document 3] Japanese Patent Laid-Open Publication No. 2006-57089

[Patent Document 4] Japanese Patent Laid-Open Publication No. 2011-162579

[Patent Document 5] Japanese Patent Laid-Open Publication No. 2012-131980

A method of obtaining a laminate using an adhesive composition is usually a state in which another substrate (subject object) is superposed on the formed adhesive layer after the adhesive composition is applied onto the substrate (the next object). Next, a method of hardening the adhesive layer sandwiched between the two substrates is performed. Hereinafter, the above-mentioned "hardening of the adhesive layer" The "step" is called the "aging step."

In the invention described in Patent Document 1 to Patent Document 4, specifically, an alicyclic polyisocyanate component or an aliphatic polyisocyanate component is used as the polyisocyanate component. Since the alicyclic polyisocyanate component or the aliphatic polyisocyanate component is relatively mild, the aging step needs to be carried out at 40 ° C to 50 ° C for 2 days to 5 days. However, in the market, it is required to provide an adhesive composition which can age in a shorter period of time and exhibits an equivalent performance of the same.

Formed with an alicyclic polyisocyanate component or an aliphatic polyisocyanate Since the aromatic polyisocyanate component is more reactive than the fraction, it is in accordance with the problem of shortening the aging time. However, since the aromatic polyisocyanate component is highly reactive, the reaction with the polyol component and the reaction with water in the environmental humidity compete with each other, and in order to exhibit sufficient adhesion, it is necessary to apply the coating and overlap. And the environmental humidity during aging is strictly managed to low humidity. Therefore, in the market, it is required to provide an adhesive composition which can be aged in a shorter period of time and exhibits an equivalent or more adhesive performance even if the environmental humidity is not strictly managed to a low humidity.

The invention described in Patent Document 5 can be aged in a relatively short period of time and The subsequent performance is exhibited, but after the polyol component and the polyisocyanate component are mixed, the viscosity is extremely increased in a short period of time, that is, the application period of the adhesive composition is shortened.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an aging that can be performed in a shorter time than before, without strictly managing the environmental humidity to a low humidity. An adhesive composition exhibiting an adhesive performance equal to or higher than the same, and having a long pot life, and a laminate using the above-described adhesive composition and a method for producing the same.

The present invention has been made in view of the above problems, and is a polyisocyanate component. (A) comprising a polyisocyanate component derived from two kinds of aromatic isocyanates and a polyether polyol; and as the polyol component (B), a polyester diol containing a specific molecular weight and a relatively low molecular weight diol Or a polyol component of a triol.

That is, the present invention relates to an adhesive composition comprising a polyisocyanate component (A) and a polyol component (B), and the above polyisocyanate component (A) is such that it is necessary to have 2,4'-diphenylmethane. Reactivity of diisocyanate (a1) and isocyanate of 4,4'-diphenylmethane diisocyanate (a2) and polyol which must have polyether polyol (a3) in an excess of isocyanate groups The above-mentioned polyol component (B) is a polyester diol (b1) having a number average molecular weight of 500 or more and 3,000 or less, and a diol (b2) and a quantity having a number average molecular weight of 50 or more and less than 500. A polyol composition of at least one of a triol (b3) having an average molecular weight of 50 or more and less than 500.

The adhesive composition of the present invention is preferably 2,4'-diphenylmethane diiso. In 100 mol% of the total of cyanate ester (a1) and 4,4'-diphenylmethane diisocyanate (a2), 2,4'-diphenylmethane diisocyanate (a1) is set to 10 mol. % or more and 60 mol% or less, and 4,4'-diphenylmethane diisocyanate (a2) is 40 mol% or more and 90 mol% or less.

Moreover, it is preferable that the adhesive composition of the present invention contains 60% by mass or more and 99% by mass or less of the polyester diol (b1) in 100% by mass of the polyol component (B). The total amount of the diol (b2) and the triol (b3) is 1% by mass or more and 40% by mass or less.

Moreover, when the number of hydroxyl groups in the polyol component (B) is 100 mol, the number of moles of the isocyanate group in the polyisocyanate component (A) is preferably 70 mol or more and 300 m or less. .

Further, the adhesive composition of the present invention is preferably a solventless type.

Further, the adhesive composition of the present invention is preferably an adhesive for laminating a packaging material.

Moreover, the present invention relates to a laminate which is used as described above The adhesive composition of the invention is formed by laminating at least two sheet-like substrates.

Moreover, the present invention relates to a method of manufacturing a laminated body, which will be The adhesive composition of the present invention is applied onto the first sheet-like substrate to form an adhesive layer, and the second sheet-like substrate is superposed on the adhesive layer to form the above-mentioned between the two sheet-like substrates. The layer is then hardened.

According to the present invention, there is an excellent effect that it is possible to provide an adhesive composition which can be aged in a shorter period of time and exhibits an equal or higher adhesive performance even if the environmental humidity is not strictly controlled to a low humidity, and has a long pot life. And a laminate using the above-described adhesive composition and a method for producing the same.

The adhesive composition of the present invention comprises a polyisocyanate component (A) and more The alcohol component (B).

The polyisocyanate component (A) is such that it is necessary to have 2,4'-diphenylmethane diisocyanate (a1) and 4,4'-diphenylmethane diisocyanate (4,4'). -diphenylmethane diisocyanate) A reactive product of an isocyanate of (a2) and a polyol which must have a polyether polyol (a3) in an excess of an isocyanate group. Hereinafter, 2,4'-diphenylmethane diisocyanate (a1) may be simply referred to as 2,4'-MDI (a1), and 4,4'-diphenylmethane diisocyanate (a2) may be abbreviated as 4 , 4'-MDI (a2).

The polyol component (B) is a polyester diol (b1) having a number average molecular weight of 500 or more and 3,000 or less, and a diol (b2) having a number average molecular weight of 50 or more and less than 500, and a number average molecular weight of A polyol composition of at least one of a triol (b3) of 50 or more and less than 500.

With the above configuration, it is possible to provide strict management of the environmental humidity even if Low humidity, can also be aged in a shorter period of time and exhibits an equivalent adhesive performance, and a long-lasting adhesive composition. The adhesive composition of the present invention does not exclude the case of containing a solvent, but is also excellent in terms of a solventless type. In addition, the solvent-free type is a solvent that does not substantially contain a solvent, and contains a solvent that is inevitably left in a production step or the like, or a trace amount of solvent that does not affect the properties, and is also included in the present invention. Solvent type. Hereinafter, the present invention will be described in detail.

Polyisocyanate component (A) contains: 2,4'-MDI (a1) and multiple The urethane prepolymer obtained by the reaction of alcohol and the 4,4'-MDI (a2) are opposite to the polyol a mixture of urethane prepolymers; or / and 2,4'-MDI (a1) and 4,4'-MDI (a2) are reacted with a polyhydric alcohol. Ester prepolymer. In addition, unreacted 2,4'-MDI (a1) or unreacted 4,4'-MDI (a2) may be included.

By using 4,4'-MDI(a2) and 2,4'-MDI(a1) as a combination The isocyanate component (A) exhibits sufficient adhesion performance even when it is aged for a short period of time. On the other hand, by using 2,4'-MDI (a1) in combination with 4,4'-MDI (a2), even in the high-humidity environment, coating, overlapping, and aging can be fully followed. performance. Further, in 100 mol% of the total of 2,4'-MDI (a1) and 4,4'-MDI (a2), it is preferable that 2,4'-MDI (a1) is 10 mol%. 60 mol% (including the upper limit and the lower limit. The same applies hereinafter), and 4,4'-MDI (a2) is set to 40 mol% to 90 mol%. By setting the composition ratio of the two MDIs to the above range, even if the environmental humidity is not strictly controlled to a low humidity, it is possible to age in a shorter period of time and more effectively exhibit the same or higher bonding performance.

The polyol forming the polyisocyanate component (A) will be described. The polyol contains a polyether polyol (a3) as an essential component, and may further contain a polyester polyol. Since the polyether polyol has a low viscosity in a molten state as compared with a polyester polyol, it is important to have a polyether polyol in the case of forming a polyisocyanate component (A) as a constituent component of an adhesive. A3). Further, by using a polyester polyol in combination, the compatibility with the polyol component (B) described later can be improved, and the cohesive force of the adhesive composition can be improved.

When the polyester polyol is used in combination, the viscosity of the adhesive composition is preferably 30% by mass or less, more preferably 1% by mass based on 100% by mass of the polyol. ~30% by mass, particularly preferably 1% by mass to 20% by mass.

Examples of the polyether polyol (a3) include, for example, water and ethylene. a low molecular weight polyol such as an alcohol, propylene glycol, trimethylolpropane or glycerin as a starting agent, and a polycondensation of an oxirane compound such as ethylene oxide, propylene oxide, butylene oxide or tetrahydrofuran. Ether polyols and the like.

As the polyether polyol (a3), in addition to the bifunctional group, a trifunctional group can be used. The above. Further, it is also possible to use a combination of a plurality of different functional groups. The number average molecular weight of the polyether polyol (a3) is preferably 100 or more and 5,000 or less. Further, a plurality of polyether polyols (a3) having different numbers and average molecular weights may be combined and used.

As the polyester polyol to be used in combination, a polyvalent carboxylic acid component and A polyester polyol obtained by reacting a diol component.

Examples of the polyvalent carboxylic acid component include polycarboxylic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, and sebacic acid, or such dialkyl esters or a mixture thereof. Examples of the diol component include ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, 1,6-hexanediol, and 3-methyl-1,5-pentanediol. A glycol such as 3,3-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, or polytetramethylene ether glycol or a mixture thereof.

The polyisocyanate component (A) used in the present invention can, for example, be obtained by reacting a mixture of 2,4'-MDI (a1) with 4,4'-MDI (a2) and a polyol which must have a polyether polyol (a3). . Alternatively, the polyisocyanate component (A) can also be reacted by reacting 2,4'-MDI (a1) with 4,4'-MDI (a2) and a polyol which must have a polyether polyol (a3), and The obtained reaction product is obtained by mixing. Moreover, polyisocyanuric acid The ester component (A) can also be obtained by reacting 2,4'-MDI (a1) with 4,4'-MDI (a2) in sequence and a polyol which must have a polyether polyol (a3).

The polyisocyanate component (A) used in the present invention is as long as it is in an isocyanate group. The above components may be reacted under an excessive amount of conditions, and it is preferred to carry out the reaction in a range in which the equivalent ratio of the isocyanate group/hydroxy group is more than 1, and not more than 6, more preferably in the range of 1.5 or more and 4 or less.

By reacting 2,4'-MDI (a1) and 4,4'-MDI (a2) with a polyol in an equivalent ratio of the above range, a urethane prepolymer having a moderate amount average molecular weight, With a suitable amount of isocyanate groups. As a result, when the polyisocyanate component (A) and the polyol component (B) described later are mixed to obtain an adhesive composition, and the laminate is obtained by using the above-described adhesive composition, sufficient adhesive strength can be obtained.

Next, the polyol component (B) used in the present invention will be described. many As described above, the polyol component (B) must have a polyester diol (b1) having a number average molecular weight of 500 or more and 3,000 or less, and a diol (b2) having a number average molecular weight of 50 or more and less than 500 or At least any one of a triol (b3) having a number average molecular weight of 50 or more and less than 500. As a result of active research, the inventors of the present invention have found that when the polyester diol (b1) is used alone as the polyol component (B), sufficient adhesive strength cannot be obtained. Further, it has been found that when the diol (b2) or the triol (b3) is used as the polyol component (B) without using the polyester diol (b1), the application period is short, and sufficient bonding strength cannot be obtained. That is, it can be ascertained that by using a polyester diol (b1) having a specific number average molecular weight and using a diol (b2) having a specific number average molecular weight or/and a triol as the polyol component (B), The same performance as before, and at the same time, the pot life can be improved.

Examples of the polyester diol (b1) include terephthalic acid and a polycarboxylic acid such as phthalic acid, adipic acid, sebacic acid or sebacic acid or a dialkyl ester thereof or a mixture thereof, such as ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, Neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, polytetrazol A polyester diol obtained by reacting a glycol such as methyl ether glycol or a mixture thereof. Further, the polyvalent carboxylic acid or the dialkyl ester or a mixture thereof, and a lactone such as polycaprolactone, polyvalerolactone or poly(β-methyl-γ-valerolactone) may be mentioned. A polyester diol or the like obtained by subjecting ring-opening polymerization.

By using the polyester diol (b1) having a number average molecular weight within the above range, the compatibility with the polyisocyanate component (A) having a polyether polyurethane as an essential constituent component is improved. A clear adhesive composition can be obtained and can exhibit sufficient adhesion properties.

Examples of the diol (b2) having a number average molecular weight of 50 or more and less than 500 include a polyester diol, a polyether diol, a polyether ester diol, a polyester guanamine diol, and an acrylic diol. Polycarbonate diol; ethylene glycol, propylene glycol, diethylene glycol, butanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3 a low molecular weight diol such as dimethylol heptane or 2-methyl-1,3-propanediol; or a mixture of these. Among these, from the viewpoint of reactivity, low molecular weight diols are preferred.

Examples of the polyester diol include dibasic acids such as terephthalic acid, isophthalic acid, adipic acid, sebacic acid, and sebacic acid, or dialkyl esters thereof or mixtures thereof. With, for example, ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, new 2-functional two of pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 3,3'-dimethylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, etc. a polyester diol obtained by reacting an alcohol or a mixture thereof, or a ring-opening polymerization of a lactone such as polycaprolactone, polyvalerolactone or poly(β-methyl-γ-valerolactone) The obtained polyester diol.

Examples of the polyether diol include, for example, water, ethylene glycol, and the like. A polyether diol obtained by polymerizing an epoxy compound such as ethylene oxide, propylene oxide, butylene oxide or tetrahydrofuran as a starting agent such as a bifunctional low-component polyol such as propylene glycol.

Examples of the polyether ester polyol include terephthalic acid, A polyether ester diol obtained by reacting a dibasic acid such as isophthalic acid, adipic acid, sebacic acid or sebacic acid or a dialkyl ester thereof or a mixture thereof with the above polyether diol.

As the above polyester guanamine diol, in the above esterification reaction, for example, by An aliphatic diamine having an amine group such as ethylenediamine, propylenediamine or hexamethylenediamine is used together as a raw material.

As an example of the above acrylic diol, 1 is contained in one molecule One or more hydroxyl group-containing hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate or the like, or a corresponding methacrylic acid derivative or the like, which is obtained by copolymerizing, for example, acrylic acid, methacrylic acid or an ester thereof.

The polycarbonate diol is, for example, selected from the group consisting of ethylene Alcohol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 1 , one or more diols of 8-nonanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanediol, and 1,4-cyclohexanedimethanol, and Dimethyl carbonate, diphenyl carbonate, ethyl carbonate, phosgene, etc. Those who deserve it.

As a triol having a number average molecular weight of 50 or more and less than 500 (b3): polyether triol, castor oil; low molecular weight triol such as trimethylolpropane or glycerin; or a mixture thereof. Among these, from the viewpoint of reactivity, a low molecular triol or a polyether triol is preferred.

As the above polyether triol, for example, trishydroxypropyl propyl is used. A polyether triol obtained by polymerizing a low-component triol such as an alkane or glycerin with an epoxy compound such as ethylene oxide, propylene oxide, butylene oxide or tetrahydrofuran.

The polyol component (B) is 100% by mass of the polyol component (B). It is preferable that the diol (b1) is 60% by mass or more and 99% by mass or less, and the total of the diol (b2) and the triol (b3) is 1% by mass or more and 40% by mass or less. By the composition ratio of the diol (b1) or the like being in the above range, sufficient pot life and adhesion properties can be exhibited. More preferably, the polyol component (B) is more preferably contained in an amount of 80% by mass or more and 95% by mass or less based on 100% by mass of the diol (b1), and diol (b2) and triol (b3). The total amount is 5 mass% or more and 20 mass% or less.

The polyol component (B) is in addition to the above diol (b1), diol (b2), and three Other than the alcohol (b3), other polyol components may be contained within a range not impairing the object of the present invention.

The adhesive composition of the present invention is a hydroxyl group in the polyol component (B) When the molar number is 100 mol, the number of isocyanate groups in the polyisocyanate component (A) is preferably 70 mol or more and 300 mol or less. By setting the number of moles of isocyanate to 70 mol or more, and having sufficient adhesion strength, and at the isocyanate group When the molar number is 300 mTorr or less, the state of the adhesive layer on the vapor deposition surface can be favorably formed. A more preferable range of the upper limit is 250 m or less, a preferred range is 230 m or less, a more preferable range of the lower limit is 100 m or more, and a more preferable range is 150 m or more.

The adhesive composition of the present invention is preferably free of a solvent. In the absence of ingredients In the case of fluidity, it is preferred to heat each component to such an extent that fluidity can be ensured. If fluidity is ensured, it may not be heated during the preparation.

The viscosity of the polyisocyanate component (A), the polyol component (B) component, and other additives described later, etc., is preferably 50 mPa at any temperature in the range of 25 ° C to 50 ° C. Above s, 5,000mPa. Below s, more preferably 100mPa. Above s, 3,000mPa. s below.

Further, in the present invention, the term "just after mixing" means that the viscosity is within 5 minutes after uniform mixing, and the viscosity is represented by a value obtained by a B-type viscometer. The viscosity exceeds 5,000 mPa at any temperature ranging from 25 ° C to 50 ° C. In the case of s, it is difficult to apply and it is difficult to ensure good workability, and even if the coating temperature is raised to 100 ° C, a good coating appearance cannot be obtained. Further, when the coating is carried out at 100 ° C or higher, the film is stretched to cause a shift in the pitch of the printed pattern, which tends not to be laminated. On the other hand, the viscosity is less than 50mPa at any temperature in the temperature range of 25 ° C ~ 50 ° C. In the case of s, there is a tendency that the initial cohesive force is weak and sufficient adhesive performance cannot be obtained, or the thickness of the coating film becomes uneven when the adhesive is applied to the substrate, resulting in poor appearance or warpage.

The adhesive composition of the present invention can be further used, for example, as needed, as needed Additives such as oxidizing agents, ultraviolet absorbers, water-repellent agents, anti-mold, anti-adhesives, plasticizers, defoamers, pigments, fillers, etc. Further, in order to further improve the adhesion performance, a bonding aid such as a decane coupling agent, a phosphoric acid, a phosphoric acid derivative, an acid anhydride, or an adhesive resin can be used. Further, in order to adjust the hardening reaction, a known catalyst, an additive or the like can be used.

The method of using the adhesive composition of the present invention is not particularly limited, and as a preferred method, the following method can be exemplified. That is, the polyisocyanate component (A) and the polyol component (B) are mixed, and the adhesive composition is applied onto the surface of the sheet substrate by a solventless laminator. The coating amount of the composition of the second embodiment is appropriately selected depending on the type of the substrate, the coating conditions, and the like, and is usually 1.0 g/m ² or more and 5.0 g/m ² or less, preferably 1.5 g/m ² or more and 4.5 g. /m ² or less.

Then, the bonding surface of the sheet-form substrate is bonded to another sheet-like substrate, and aged at room temperature or under heating to be cured. In the case of the adhesive composition of the present invention, the time required for aging is about one day. Further, in the case of the adhesive composition of the present invention, sufficient environmental performance can be exhibited even if the environmental humidity from the application to the aging is high.

By using the adhesive composition of the present invention to laminate a sheet-like substrate Get a layered body. As the sheet-like substrate, a plastic film such as polyester, polyamide, polyethylene, or polypropylene can be used, and a metal deposition film such as aluminum, cerium oxide, or aluminum oxide is deposited, and stainless steel, iron, copper, lead, or the like can be used. Metal foil, etc. The combination of the substrates may be plastic films, plastic films and metal vapor deposited films or metal foils.

In the above Patent Document 5, as described above, there is a problem that the application period of the adhesive composition is short. In Patent Document 5, it is disclosed that the polyol component (b) is preferred. Including only triol (paragraph 52, paragraph 54, etc.), but the triol is more reactive than the diol component, so it is presumed that after the polyol component and the polyisocyanate component are mixed, it will increase extremely in a short time. Viscosity, resulting in a shorter pot life of the adhesive composition.

On the other hand, according to the present invention, due to the use of a specific number average molecular weight Polyester diol (b1), diol (b2) or/and triol (b3) having a specific number average molecular weight as a polyol component, and the above polyol component (B) in the above polyisocyanate component (A) Therefore, it is possible to provide an adhesive composition which can be aged in a shorter period of time and exhibits an equal or higher adhesive performance even if the environmental humidity is not strictly controlled to a low humidity, and has a long pot life. In particular, in the case of a solventless adhesive, the increase in viscosity in a short period of time has a great influence on coating properties and productivity, and therefore it is a big problem from the industrial viewpoint, but the adhesive composition according to the present invention When the solvent-free type is used as described above, even if the environmental humidity is not strictly managed to be low humidity, it can be aged in a shorter period of time and exhibits an equivalent performance of more than the above, and a long pot life can be achieved.

≪Example≫

Hereinafter, the present invention will be more specifically described by way of examples. The % and the parts in the examples and comparative examples are all based on mass unless otherwise specified.

The number average molecular weight of polyether polyols, polyester diols, etc. by gel permeation It was determined by Gel Permeation Chromatography (GPC). The number average molecular weight measurement was carried out under the following conditions. Model: TOSOH HLC-8220GPC, column: TSKGEL SuperHM-M, solvent: Tetrahydrofuran (THF), solution flow rate: 0.6ml per minute, temperature: 40 ° C, detector: differential refractometer, molecular weight standard: polystyrene acid value, hydroxyl value expressed in mg per gram of polymer polyol KOH. The acid value was determined by neutralization titration with KOH, and the hydroxyl value was determined by acetylation of pyridine and acetic anhydride. Further, the NCO content rate is a mass fraction indicating the amount of isocyanate groups present in the sample. The NCO content is determined by adding an excess of a toluene solution of dibutylamine to form a corresponding urea, and then performing a reverse titration by an indicator titration method using a hydrochloric acid standard solution.

(Synthesis Example 1) Into a reaction vessel, water and propylene oxide were added thereto. 30 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 400, 40 parts of a bifunctional polypropylene glycol having a number average molecular weight of about 2,000, and a trifunctional group having a number average molecular weight of about 400 obtained by adding glycerin to propylene oxide 20 parts of polypropylene glycol, 40 parts of 4,4'-diphenylmethane diisocyanate, and 60 parts of 2,4'-diphenylmethane diisocyanate were heated at 70 ° C to 80 ° C for 3 hours while stirring under a nitrogen stream. A urethanation reaction. A polyether polyurethane polyisocyanate resin having an isocyanate group is obtained. The isocyanate group content was 14.4%. Hereinafter, this resin is referred to as polyisocyanate A-(1).

(Synthesis Example 2) setting 4,4'-diphenylmethane diisocyanate: 70 parts, A polyether polyurethane polyisocyanate resin having an isocyanate group was obtained in the same manner as in Synthesis Example 1, except that 2,4'-diphenylmethane diisocyanate was used. The isocyanate group content was 11.5%. Hereinafter, this resin is referred to as polyisocyanate A-(2).

(Synthesis Example 3) setting 4,4'-diphenylmethane diisocyanate: 76 parts, A polyether polyurethane polyisocyanate resin having an isocyanate group was obtained in the same manner as in Synthesis Example 1, except that 2,4'-diphenylmethane diisocyanate was used in an amount of 38 parts. The isocyanate group content was 16.5%. Hereinafter, this resin is referred to as polyisocyanate A-(3).

(Synthesis Example 4) setting 4,4'-diphenylmethane diisocyanate: 100 parts, A polyether polyurethane polyisocyanate resin having an isocyanate group was obtained in the same manner as in Synthesis Example 1, except that 2,4'-diphenylmethane diisocyanate was not used. The isocyanate group content was 14.4%. Hereinafter, this resin is referred to as polyisocyanate A-(4).

(Synthesis Example 5) 4,4'-diphenylmethane diisocyanate was not used, and A polyether polyurethane polyisocyanate resin having an isocyanate group was obtained in the same manner as in Synthesis Example 1, except that 2,4'-diphenylmethane diisocyanate was used in an amount of 100 parts. The amount of isocyanate groups was 14.4%. Hereinafter, this resin is referred to as polyisocyanate A-(5).

(Synthesis Example 6) 4,4'-diphenylmethane diisocyanate and 2,4'- were not used. A polyether polyurethane having an isocyanate group was obtained in the same manner as in Synthesis Example A-1 except that diphenylmethane diisocyanate was replaced with isophorone diisocyanate (IPDI): 90 parts. Polyisocyanate resin. The amount of isocyanate groups was 14.6%. Hereinafter, this resin is referred to as polyisocyanate A-(6).

(Synthesis Example 7) 438 parts of isophthalic acid were placed in the reaction vessel, and 106 parts of diol and 179 parts of neopentyl glycol were heated to 150 ° C to 240 ° C while stirring under a nitrogen stream to carry out an esterification reaction. When the acid value was 1.3 (mgKOH/g), the reaction temperature was set to 200 ° C, and the inside of the reaction vessel was gradually reduced in pressure, and the reaction was carried out for 1.3 minutes at 1.3 kPa or less to obtain an acid value of 0.4 (mgKOH/g). A polyester diol resin having a hydroxyl value of 137 (mgKOH/g) and a number average molecular weight of about 800 and having a hydroxyl group at both terminals. Hereinafter, this polyol is referred to as polyol (b1)-1.

(Synthesis Example 8) 373 parts of isophthalic acid were charged into a reaction container, and 42 parts of phthalic acid, 109 parts of ethylene glycol, and 182 parts of neopentyl glycol were heated to 150 ° C to 240 ° C while stirring under a nitrogen stream to carry out an esterification reaction. When the acid value was 1.3 (mgKOH/g), the reaction temperature was set to 200 ° C, and the inside of the reaction vessel was gradually reduced in pressure, and reacted at 1.3 kPa or less for 30 minutes to obtain an acid value of 0.5 (mgKOH/g). A polyester diol resin having a hydroxyl value of 184 (mgKOH/g) and a number average molecular weight of about 600 and having a hydroxyl group at both terminals. Hereinafter, the resin is referred to as polyester Glycol (b1)-2.

(Synthesis Example 9) 298 parts of isophthalic acid were charged into a reaction container. 262 parts of diacid, 341 parts of ethylene glycol, and 219 parts of diethylene glycol were heated to 150 ° C to 240 ° C while stirring under a nitrogen stream to carry out an esterification reaction. When the acid value was 1.3 (mgKOH/g), the reaction temperature was set to 200 ° C, and the inside of the reaction vessel was slowly depressurized, and the reaction was carried out for 1.3 minutes at 1.3 kPa or less to obtain an acid value of 0.5 (mgKOH/g) and hydroxy group. A polyester diol resin having a hydroxyl group at both terminals having a value of 40.7 (mgKOH/g) and a number average molecular weight of about 2,800. Hereinafter, this resin is referred to as polyester diol (b1)-3.

(Synthesis Example 10) 186 parts of isophthalic acid were charged into a reaction container, 383 parts of adipic acid and 429 parts of neopentyl glycol were heated to 150 ° C to 240 ° C while stirring under a nitrogen stream to carry out an esterification reaction. When the acid value was 1.3 (mgKOH/g), the reaction temperature was set to 200 ° C, and the inside of the reaction vessel was slowly decompressed, and the reaction was carried out for 1.3 minutes at 1.3 kPa or less to obtain an acid value of 0.4 (mgKOH/g) and hydroxy group. A polyester diol resin having a hydroxyl group at both terminals having a value of 27.3 (mgKOH/g) and a number average molecular weight of about 4,000. Hereinafter, this resin is referred to as polyester diol (b1)-4.

(Synthesis Example 11) Injecting cis-1,4-cyclohexanedicarboxylic acid into a reaction vessel 310 parts of 415 parts of 1,4-cyclohexanedimethanol were heated to 150 ° C to 220 ° C while stirring under a nitrogen stream to carry out an esterification reaction. When the acid value was 3.0 (mgKOH/g), the reaction temperature was set to 200 ° C, and the inside of the reaction vessel was gradually reduced in pressure, and reacted at 1.3 kPa or less for 30 minutes to obtain an acid value of 2.0 (mgKOH/g) and hydroxy group. a polymer having a hydroxyl group at both ends having a value of 332 (mgKOH/g) and a number average molecular weight of about 300 Ester diol resin. Hereinafter, this resin is referred to as polyester polyol (b2)-1.

(Example 1) 200 parts of the aggregate obtained in Synthesis Example 1 were placed in a container The isocyanate A-(1) was added to 90 parts of the polyester diol (b1)-1 obtained in Synthesis Example 7 and 10 parts of diethylene glycol while stirring under a nitrogen stream, and mixed in a warm water bath at 25 ° C. A solventless adhesive composition was obtained.

After uniform mixing, the viscosity of the composition at 25 ° C was measured within 5 minutes, and the result was 2,500 mPa. s.

Further, the solventless adhesive composition described above contains 166 mol of an isocyanate group derived from polyisocyanate A-(1) with respect to a hydroxyl group in a polyol component: 100 mol. The amount of the isocyanate group relative to 100 mol of the hydroxyl group was determined in the following manner.

Amount of isocyanate groups relative to 100 moles of hydroxyl groups = [isocyanate group (eq.) / hydroxyl group (eq.)] × 100

Isocyanate group (eq.) = NCO content (% by mass) / (42 × 100)

Hydroxyl (eq.) = 56110 / hydroxyl value

The NCO content (% by mass) was determined in accordance with JIS K7301, and the hydroxyl value was determined in accordance with JIS K1557-1.

The pot life of the obtained solvent-free adhesive composition was evaluated by the following method. Further, using the obtained solvent-free adhesive composition, a laminate was obtained by the following method, and the adhesion of the laminate and the interface state of the laminate were evaluated. The results are shown in Table 2.

(Examples 2 to 11 and Comparative Examples 1 to 8) were specified A solventless adhesive composition was obtained in the same manner as in Example 1 except that the polyisocyanate component (A) and the polyol component (B) shown in Table 2 and Table 3 were used in the same manner. Further, in the same manner as in Example 1, the pot life, the adhesion of the laminate, and the interface state of the laminate were evaluated. The results are shown in Table 2 and Table 3.

Further, in Comparative Example 8 using the polyester diol (b1)-3 having a number average molecular weight of about 2,800, Example 4, and Example 9, using a polyester diol (b1)-4 having a number average molecular weight of about 4,000. The polyester diol (b1)-3 and the polyester diol (b1)-3 are respectively heated to 70 ° C, and then mixed with polyisocyanate A-(1) or the like in a warm water bath at 25 ° C, and by The B-type viscometer measures the viscosity within 5 minutes after mixing. The temperature of the adhesive composition at the time of measurement was about 50 °C.

<Applicable Period> The useless type obtained in each of the examples or the comparative examples is connected. The coating composition was sealed with a 200 g, 250 mL capacity glass bottle with a lid, and the viscosity after 30 minutes in a 50 ° C warm water bath was measured by a B-type viscometer to study the pot life. The temperature of the adhesive composition at the time of measurement was about 50 °C.

[Preparation of a laminate] The solventless adhesive composition obtained in each of the examples or the comparative examples adjusted to 50 ° C at 70 ° C was applied to polyethylene terephthalate by a solventless test coater. Surface of a Polyethylene Terephthalate (PET) film (thickness: 12 μm) (coating amount: 2.0 g/m ² ), and an aluminum-free unstretched polypropylene film (VMCPP, thickness: 25 μm) was superposed on the coated surface. The vaporized surface is obtained, and a laminate (pre-laminated body) in the preparation stage is obtained. The pre-laminates were aged for 1 day or 2 days in an environment of 25 ° C, humidity 60% RT or 80% RT, and placed to prepare a laminate. The adhesion force and the interface state of the laminate were observed and measured for each of the obtained laminates according to the following points, and the results are shown in Tables 2 and 3.

(Continuous force) cut the laminate into a length of 300mm and a width of 15 Mm, and as a test piece. Tensile strength (N/15 mm) between PET/VMCPP was measured using an Instron type tensile tester at a peeling speed of 300 mm/min at 25 ° C. . The test was carried out 5 times and the average value was determined.

(Interfacial state of the laminate) through the PET film side from the PET film side The vapor deposition surface of the substrate was visually observed, and the interface state of the laminate (the state of the adhesive layer on the vapor deposition surface) was evaluated by the following criteria.

○: There was no orange peel pattern or a small speckled pattern on the vapor deposition surface, and the adhesive layer was uniform.

△: A little orange peel pattern or a small speckled pattern was observed on the vapor deposition surface, but it was a level of no problem in use.

×: A large number of orange peel patterns or small speckled patterns were observed on the vapor deposition surface.

According to Table 2, in Examples 1 to 11, the surface on the vapor deposition surface The state of the layer is then good, and the strength is also excellent. In particular, in the first and second embodiments, even when the environmental humidity during aging is high, sufficient adhesion strength can be exhibited in a short time. On the other hand, in Comparative Example 1 in which only a component derived from 4,4′-MDI was used as the isocyanate component, it was significantly affected by the environmental humidity at the time of aging, and when it was aged at 25° C. and 80% RT, vapor deposition was performed. The state of the adhesive layer on the face is significantly poor, and the strength is also extremely small. Further, in Comparative Example 2 using only a component derived from 2,4'-MDI as an isocyanate component, and Comparative Example 3 using only isophorone diisocyanate, it was found that the state of the adhesive layer on the vapor deposition surface was good. But then the intensity is significantly worse. Further, in the case of Comparative Example 3, the temperature at the time of initial viscosity measurement was 25 ° C, and the temperature at the time of viscosity measurement after 30 minutes from the mixing was 50 ° C. Therefore, the viscosity after 30 minutes passed was observed at a glance. In the case of the examples or the comparative examples using 2,4'-MDI and 4,4'-MDI, even if the temperature at the time of measurement differs, the viscosity after 30 minutes is large because the polyol component (A) is used. )Reaction. In other words, isophorone diisocyanate is less reactive than 2,4'-MDI and 4,4'-MDI, and does not react with the polyol component (A) at about 50 minutes at 50 °C. Therefore, almost no increase in viscosity was observed, and a decrease in apparent viscosity due to the influence of the measured temperature was observed. Further, the reason why the strength is remarkably small is presumably that the reaction is less likely to occur at a low temperature (25 ° C × 1 day or 2 days) aging.

In addition, it does not contain low molecular weight diol (b2) or triol (b3). In Comparative Example 4 which is the polyol component (B), it is understood that although the state of the adhesive layer on the vapor deposition surface is good, the strength is remarkably poor. Moreover, only low molecular weight diols are used (b2) or a triol (b3) as a polyol component (B) (Comparative Example 5, Comparative Example 6, Comparative Example 7) or a polyester diol (b1)-4 having Mn of 4,000 as a polyester diol (b1) (Comparative Example 8) It was found that the state of the adhesive layer on the vapor deposition surface was also poor, and the strength was remarkably poor.

Further, in Comparative Example 7, although the viscosity immediately after the mixing was not inferior to the examples, since the polyol component (B) contained only the low molecular weight triol (b3), the reaction point with the polyisocyanate component (A) was large. And the result is a significant increase in viscosity in a short period of time.

[Industrial availability]

The adhesive composition of the present invention is suitable for use in bonding various plastic films to each other and to bonding a plastic film to a metal deposition film or a metal foil, and is particularly suitable for use as a packaging material for food, medical products, cosmetics, and the like. Use an adhesive. Further, although it is suitable for joining the film-like films, the thickness is not limited, and the adhesive composition of the present invention can be preferably used in the joining of various shapes or forms. Moreover, the adhesive composition of the present invention can be widely applied to all solventless adhesives because it can be preferably used in a solventless type.

Claims (8)

An adhesive composition comprising: a polyisocyanate component (A); and a polyol component (B), wherein the polyisocyanate component (A) is such that it is necessary to have 2,4'-diphenylmethane diisocyanate (a1) And a reactive product of an isocyanate of 4,4'-diphenylmethane diisocyanate (a2) and a polyol having a polyether polyol (a3), which is reacted under an excess of an isocyanate group, and the above polyol The component (B) is a polyol composition, and it is necessary to have a polyester diol (b1) having a number average molecular weight of 500 or more and 3,000 or less, and a diol (b2) and a quantity having a number average molecular weight of 50 or more and less than 500. At least one of the triols (b3) having an average molecular weight of 50 or more and less than 500. The adhesive composition according to claim 1, wherein the total of the above 2,4'-diphenylmethane diisocyanate (a1) and the above 4,4'-diphenylmethane diisocyanate (a2) In 100 mol%, the 2,4'-diphenylmethane diisocyanate (a1) is 10 mol% or more and 60 mol% or less, and the 4,4'-diphenylmethane diisocyanate (a2) is 40% or more, 90% or less. The adhesive composition according to the first or second aspect of the invention, wherein the polyester diol (b1) is contained in an amount of 60% by mass or more and 99% by mass or less based on 100% by mass of the polyol component (B1). The total amount of the above diol (b2) and the above triol (b3) is 1% by mass or more and 40% by mass or less. The adhesive composition according to claim 1 or 2, wherein the polyisocyanate component (A) is used when the hydroxyl group number in the above polyol component (B) is 100 mol. The isocyanate group has a molar number of 70 m or more and 300 m or less. An adhesive composition as described in claim 1 or 2, which is a solventless type. The adhesive composition according to claim 1 or 2, which is an adhesive for laminating a packaging material. A laminate obtained by laminating at least two sheet substrates using the adhesive composition according to any one of claims 1 to 6. A method for producing a laminate, which comprises applying an adhesive composition according to any one of claims 1 to 6 to a first sheet-like substrate to form an adhesive layer, and The second sheet-like substrate is superposed on the subsequent layer, and the above-mentioned adhesive layer between the two sheet-like substrates is cured.