JP2022003111A - Adhesive for laminating - Google Patents

Abstract

To provide a laminate adhesive wherein when laminating plastic films to produce a laminate film, the adhesive has excellent adhesive strength to the cured film, each component has excellent compatibility, it does not impair the appearance of the laminate film, it has a moderate pot life, and it allows efficient coating work and film production.SOLUTION: A laminate adhesive is prepared by blending (A) an urethane prepolymer having an isocyanate group as a terminal, (B) a polyol component, (C) a rosin ester and (D) a castor oil-based compound. Relative to 100 pts.mass of the (B) component, 50-250 pts.mass of the (C) component is blended.SELECTED DRAWING: None

Description

The present invention relates to a laminating adhesive, and more particularly to a laminating adhesive which is excellent in stability and adhesiveness and does not impair the appearance of the film when a plurality of films are bonded together, and a laminating film using the same.

When manufacturing packaging materials for foods, medical products, cosmetics, etc., and substrates such as FPC substrates and TAB substrates, plastic films (for example, films such as polyethylene, polypropylene, nylon, polyester, and polyimide), metal-deposited films, And a composite film in which a metal foil (for example, a foil such as aluminum and copper) is bonded is used. As an adhesive for adhering these plastic films, metal vaporized films, metal foils and the like, urethane adhesives in which organic polyols and organic isocyanates are combined are known.

In recent years, there has been an increasing demand for solvent-free adhesives as urethane adhesives in consideration of environmental aspects, simple equipment, cost merits, and the like. Compared to solvent-based adhesives, solvent-free adhesives have the advantage of not using a solvent, but they have poor wettability, and when a plurality of films are bonded together, air bubbles are likely to occur on the film surface, resulting in a film appearance. May reduce. In particular, polyethylene terephthalate films on which aluminum is vapor-deposited often have poor appearance.

Patent Documents 1 to 3 disclose a laminated film laminated with a urethane adhesive.
Patent Document 1 discloses a urethane adhesive composition obtained by mixing a polyisocyanate and a polyol, and a liquid ester at 25 ° C., and a laminate obtained by applying the composition ([Patent Claims]. Range], [Table 1] to [Table 6]).

Patent Document 2 discloses a solvent-free laminated adhesive having a polyisocyanate, a polyol, and castor oil (or a castor oil derivative) (see [Claims], [Table 1], and [Table 2]).

Patent Document 3 discloses a one-component adhesive having a polyester-based urethane resin, a specific polyol, and a polyisocyanate (see [Claims]). Table 4 discloses an adhesive having a polyester-based urethane resin, a rosin ester, and diphenylmethane diisocyanate (see [Claim 4] and [Table 4]).

Patent Documents 1 to 3 describe that the appearance of the laminated film is improved (see Patent Document 1 [0017], Patent Document 2 [0015], and Patent Document 3 [0005]), but the high demands of consumers are sufficient. I couldn't say that I met. Further, considering the work efficiency when manufacturing a packaging bag from a laminated film, it is desired that the adhesive has excellent compatibility of each component and adhesive strength to the film after curing. Further, considering the work efficiency of the worker and the production efficiency of the film, the adhesive is required to have a gradual increase in viscosity (a pot life is long to some extent).

Japanese Unexamined Patent Publication No. 2018-162420 International release 2016/152370 Japanese Unexamined Patent Publication No. 8-046862

The present invention has been made to solve such a problem, and when a laminated film is manufactured by laminating plastic films, it has excellent adhesive strength to the film after curing, excellent compatibility of each component, and a laminated film. To provide a laminating adhesive that does not impair the appearance of the film, has an appropriate pot life, and can efficiently perform coating work and film production, and a laminated film having an excellent appearance manufactured by using the laminating adhesive. The purpose.

As a result of diligent studies to solve the above problems, the present inventor has made a urethane resin composition having a urethane prepolymer, a polyol, and a specific plasticizer excellent in compatibility with each component, and obtained a plastic film. We have found that when a laminated film is manufactured by laminating, it has excellent adhesive strength to the film, has a moderate increase in viscosity and has an appropriate pot life, and does not impair the appearance of the laminated film, and has completed the present invention.

The present specification includes the following aspects.
1. 1. It is obtained by blending (A) a urethane prepolymer having an isocyanate group at the end, (B) a polyol component, (C) a rosin ester, and (D) a castor oil-based compound.
A laminating adhesive containing 50 to 250 parts by mass of the component (C) per 100 parts by mass of the component (B).
2. 2. The laminating adhesive according to 1, wherein the component (C) is blended in an amount of 100 to 150 parts by mass per 100 parts by mass of the component (B).
3. 3. (B) The laminating adhesive according to 1 or 2, wherein the polyol contains a polyether polyol.
4. (C) The laminating adhesive according to any one of 1 to 3, wherein the rosin ester has a softening temperature of 80 to 120 ° C.
A laminated film in which a plurality of films are bonded to each other via the laminating adhesive according to any one of 5.1 to 4.

The laminating adhesive according to the embodiment of the present invention is obtained by blending (A) a urethane prepolymer having an isocyanate group at the end, (B) a polyol component, (C) a rosin ester and (D) a castor oil-based compound. , 50 to 250 parts by mass of the component (C) is blended per 100 parts by mass of the component (B).

By blending the components (A) to (D) in the above composition, the laminating adhesive according to the embodiment of the present invention has excellent compatibility, has a pot life of an appropriate length, and has excellent adhesive strength. ing. When the plastic film is laminated with the laminating adhesive of the embodiment of the present invention to produce the laminated film, the appearance of the laminated film is not impaired.

Since the laminated film of the embodiment of the present invention is obtained by using the above-mentioned adhesive for laminating, it can be quickly bonded, has an excellent appearance, and is efficiently produced.

FIG. 1 schematically shows a cross section of a laminated film according to an embodiment of the present invention. FIG. 2 schematically shows a cross section of a laminated film of another embodiment of the present invention.

The laminating adhesive according to the embodiment of the present invention includes (A) a urethane prepolymer having an isocyanate group at the end (hereinafter, also referred to as "(A) component"), (B) a polyol component (hereinafter, "(B) component"). (Also also referred to as), (C) rosin ester (hereinafter, also referred to as “(C) component”), (D) castor oil-based compound (hereinafter, also referred to as “(D) component”) are blended (or mixed). It is obtained and contains the components (A) to (D).

The adhesive according to the embodiment of the present invention is not particularly limited by the blending order and blending method of the components (A) to (D) as long as the desired adhesive can be obtained. The adhesive of the embodiment of the present invention can be obtained, for example, by simultaneously blending four components of (A) urethane prepolymer, (B) polyol component, and (C) rosin ester and (D) castor oil-based compound. It can be obtained by blending any of the components (A), (C), and (D) with the component (B) in advance, and then blending the remaining components, but the component (B) to ( It is more preferable to obtain D) by mixing the components in advance and blending the mixture with the component (A).

The production of the adhesive by blending (or mixing) the components (A) to (D) can be performed by using a known method. The adhesive can be obtained by blending the components (A) to (D) in a solvent, but the components (A) to (D) can also be blended without using a solvent with each other.

The adhesive according to the embodiment of the present invention is a two-component adhesive obtained by blending a first liquid containing the component (A) and a second liquid containing the components (B), (C) and (D). It may be an agent, and is a two-component adhesive obtained by blending a first liquid containing the components (A), (C) and (D) and a second liquid containing the component (B). Good.

The adhesive according to the embodiment of the present invention is a two-component adhesive containing a first liquid containing the component (A) and a second liquid containing the components (B), (C) and (D). Is more preferable. Each of the first liquid and the second liquid can appropriately contain various additives and the like described later.

<(A) Urethane prepolymer having an isocyanate group at the end>
In the embodiment of the present invention, (A) urethane prepolymer is a product obtained by reacting (a1) a polyol with (a2) an isocyanate monomer. (A) The number average molecular weight of the urethane prepolymer is preferably 1500 to 4000. (A) When the number average molecular weight of the urethane prepolymer is in the above range, the laminating adhesive of the embodiment of the present invention is more excellent in adhesiveness.

In the present specification, the number average molecular weight (Mn) is a value obtained by measuring using gel permeation chromatography (GPC) and converting using a polystyrene standard. Specifically, the value can be measured and converted using the following GPC apparatus and measuring method. As the GPC apparatus, HCL-8220GPC manufactured by Tosoh Corporation is used, and RI is used as a detector. As the GPC column, two TSKgel SuperMultipore HZMs manufactured by Tosoh Corporation are used. The sample is dissolved in tetrahydrofuran and the flow rate is 0.35 ml / min and the column temperature is 40 ° C. to obtain the measured value. Using a calibration curve using polystyrene with a monodisperse molecular weight as a standard substance, the measured values are converted to obtain the desired Mn. The same applies to the Mn of the (a1) polyol and the Mn of the (a2) isocyanate monomer, which will be described later.

In the present specification, (a1) polyol is a general term for compounds having two or more hydroxyl groups in one molecule, and examples thereof include polyether polyols, polyester polyols, acrylic polyols, polycaprolactone polyols, and polycarbonate polyols. As long as the adhesive of the embodiment of the present invention can be obtained, (a1) the type of polyol is not limited.

In the embodiment of the present invention, the number average molecular weight of (a1) "polypoly" is preferably 400 to 1300. The (a1) polyol has a short chain length when the number average molecular weight is in the above range, and is easily crosslinked with the (a2) isocyanate monomer. Since the amount of unreacted (a2) isocyanate monomer is reduced, the laminating adhesive according to the embodiment of the present invention contains more (A) urethane prepolymer and is more excellent in adhesiveness.

The (a2) isocyanate monomer in the embodiment of the present invention is not particularly limited as long as the adhesive for laminating which is the object of the present invention can be obtained, but preferably contains an aromatic isocyanate. (a2) When the isocyanate monomer contains an aromatic isocyanate, the adhesiveness of the laminating adhesive according to the embodiment of the present invention is further improved.

The "(a2) isocyanate monomer" of the embodiment of the present invention does not mean that it is composed only of aromatic isocyanate. The (a2) isocyanate monomer may contain an aliphatic isocyanate and / or an alicyclic isocyanate as long as it does not adversely affect the adhesiveness of the laminating adhesive and the appearance of the film according to the embodiment of the present invention.

As used herein, the "aliphatic isocyanate" is a compound having a chain hydrocarbon chain in which an isocyanate group is directly bonded to the hydrocarbon chain, and does not have a cyclic hydrocarbon chain. Refers to a compound. The "aliphatic isocyanate" may have an aromatic ring, but the aromatic ring is not directly bonded to the isocyanate group.
In this specification, the aromatic ring is not included in the cyclic hydrocarbon chain.

The "alicyclic isocyanate" is a compound having a cyclic hydrocarbon chain and may have a chain hydrocarbon chain. The isocyanate group may be directly bonded to a cyclic hydrocarbon chain or may be directly bonded to a possible chain hydrocarbon chain. The "alicyclic isocyanate" may have an aromatic ring, but the aromatic ring and the isocyanate group are not directly bonded.

The "aromatic isocyanate" refers to a compound having an aromatic ring and having an isocyanate group directly bonded to the aromatic ring. Therefore, even if an aromatic ring is contained in the molecule, a compound in which an isocyanate group is not directly bonded to the aromatic ring is classified into an aliphatic isocyanate or an alicyclic isocyanate.

Therefore, for example, 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 4,4'-diphenylmethane diisocyanate (OCN-C ₆ H _4- CH _2- C ₆ H _4- NCO) have an isocyanate group. Since it is directly bonded to the aromatic ring, it corresponds to an aromatic isocyanate.

On the other hand, for example, xylylene diisocyanate _{(OCN-CH 2 -C 6 H} 4 -CH 2 -NCO) , which has an aromatic ring, an isocyanate group is not directly bonded to an aromatic ring, since the bonded methylene group , Corresponds to the aliphatic isocyanate.
The aromatic ring may have two or more benzene rings fused.

Examples of the aromatic isocyanate include 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate and the like.

As the aliphatic isocyanate, for example, 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, 1,6-diisocyanatohexane (hereinafter, HDI), 1,6-diisocyanato-2,2,4 Examples thereof include −trimethylhexane, methyl 2,6-diisocyanatohexaneate (lysine diisocyanate), and 1,3-bis (isocyanatomethyl) benzene (xylylene diisocyanate).

Examples of the alicyclic isocyanate include 5-isocyanato-1-isocyanatomethyl-1,3,3-trimethylcyclohexane (isophorone diisocyanate: IPDI) and 1,3-bis (isocyanatomethyl) cyclohexane (hydrogenated xylylene diisocyanate). ), Bis (4-isocyanatocyclohexyl) methane (hydrogenated diphenylmethane diisocyanate), 1,4-diisocyanatocyclohexane and the like can be exemplified.

In the embodiment of the present invention, the reaction method of (a1) polyol and (a2) isocyanate monomer is not limited as long as the (A) urethane prepolymer of the embodiment of the present invention can be obtained, and is general. A urethanization reaction method can be used. For example, bulk polymerization that does not use a solvent and solution polymerization that uses a solvent can be used, and a catalyst can be used if necessary by heating and stirring as appropriate. Furthermore, various additives may be used in the reaction between the (a1) polyol and the (a2) isocyanate monomer.
Examples of the commercially available urethane prepolymer (A) include the Loctite LIOFOL LA series manufactured by Henkel Japan Ltd.

<(B) polyol component>
In the embodiment of the present invention, the "(B) polyol component" is generally used for a laminating adhesive, and the desired laminating adhesive of the embodiment of the present invention can be obtained, and the adhesive can be produced. It is not particularly limited as long as it does not adversely affect. Examples of the polyol component (B) include polyester polyols, acrylic polyols, polyether polyols, polycaprolactone polyols, polyether polyester polyols, polyester polyurethane polyols, polyether polyurethane polyols, and modified products of these polyols.

(B) The polyol component preferably contains a polyether polyol.
By containing the polyether polyol, the laminating adhesive of the embodiment of the present invention further suppresses the increase in viscosity, makes the pot life more appropriate, and is more suitable for the coating operation.

The polyether polyol usually means what is understood as a polyether polyol, and is not particularly limited as long as the adhesive for laminating which is the object of the present invention can be obtained. Examples of the polyether polyol include polyethylene glycol (PEG), polyoxytetramethylene glycol (PTMG), polypropylene glycol (PPG) and the like. Polyether polyols can be used alone or in combination.

Generally, the polyether polyol is a low molecular weight compound having two or more hydroxyl groups in the molecule such as propylene oxide, ethylene oxide and the like, propylene glycol, glycerin, sorbitol and sucrose and / or polyamine. It is manufactured by addition polymerization to the like.

The laminating adhesive of the embodiment of the present invention preferably contains polypropylene glycol as a polyether polyol. By containing polypropylene glycol, the laminating adhesive of the embodiment of the present invention is more suitable for application work to a film at the time of manufacturing a laminated film because a sudden increase in viscosity is further suppressed.

<(C) Rosin ester>
In the embodiment of the present invention, the (C) rosin ester refers to a rosin ester that can be generally used as an adhesive, and is not particularly limited as long as the adhesive for laminating of the embodiment of the present invention can be obtained. .. The rosin generally includes natural rosin, modified rosin, hydrogenated rosin and the like, and the (C) rosin ester generally contains esters such as natural rosin, modified rosin and / or hydrogenated rosin. Examples of the rosin ester include a glycerol ester of natural rosin, a glycerol ester of modified rosin, a glycerol ester of hydrogenated rosin, a pentaerythritol ester of natural rosin, a pentaerythritol ester of modified rosin, and a pentaerythritol ester of hydrogenated rosin.
By containing the component (C) in the laminating adhesive according to the embodiment of the present invention, the compatibility of each component is improved, and the adhesive strength and stability are improved.

In an embodiment of the present invention, the component (C) preferably contains a rosin ester having an acid value of 0 to 50 mgKOH / g, and more preferably contains a rosin ester having an acid value of 0 to 30 mgKOH / g. Most preferably, it contains a rosin ester having a value of 0 to 10 mgKOH / g. When the acid value of the rosin ester is within the range, the laminating adhesive of the embodiment of the present invention is more suppressed in viscosity increase and more stable.

In the present invention, the (C) rosin ester preferably has a softening point of 80 to 120 ° C., particularly preferably a softening point of 85 to 110 ° C., and most preferably a softening point of 80 to 100 ° C. (C) When the softening point of the rosin ester is within the above range, the laminating adhesive of the embodiment of the present invention can maintain a more appropriate hardness, is superior in adhesive strength, and is applied to a film. At the same time, it is possible to prevent the generation of air bubbles and further improve the appearance of the film.

(C) As the rosin ester, a commercially available product can be used. As such commercial products, KOMOTAC KB90H (trade name), KOMOTAC KH100 (trade name), KOMOTAC KHR75 (trade name), KOMOTAC K107 (trade name) manufactured by GUNDONG KOMO Co., Ltd .; Foralyn 5020 manufactured by Eastman Chemical Co., Ltd. -F (trade name), Foral AX-E (trade name), Floral 85E (trade name) and the like can be mentioned.

As an embodiment of the present invention, it is preferable that the component (C) is blended in an amount of 50 to 250 parts by mass, and more preferably the component (C) is blended in an amount of 100 to 150 parts by mass per 100 parts by mass of the component (B). .. By blending both components in the above proportions, the laminating adhesive of the embodiment of the present invention has excellent compatibility, the increase in viscosity is further suppressed, the pot life becomes more appropriate length, and the adhesive strength is increased. It is also superior, and in particular, it has a pot life of a more appropriate length, so that the workability of application to an adherend can be further improved. When laminating plastic films to produce a laminated film, the laminating adhesive of the embodiment of the present invention is applied more uniformly to the film, so that the appearance of the laminated film is not impaired more.

<(D) Castor oil compound>
The laminating adhesive of the embodiment of the present invention contains (D) a castor oil-based compound. (D) By containing the castor oil-based compound, the adhesive strength of the laminating adhesive is improved. (D) The castor oil-based compound is not particularly limited as long as the adhesive for laminating of the embodiment of the present invention can be obtained, the type thereof is not limited, and even if it is modified, it has not been modified. It may be denatured, hydrogenated or unhydrated.

Examples of castor oil-based compounds include castor oil and castor oil derivatives. By containing castor oil and / or castor oil derivative, the laminating adhesive according to the embodiment of the present invention has improved compatibility and excellent adhesive strength.

Castor oil is a type of vegetable oil collected from the seeds of sesame seeds of the family Todaigusa, and is composed of unsaturated fatty acids (for example, 87% ricinoleic acid, 7% oleic acid, 3% linoleic acid) and a small amount of saturated fatty acids (for example, 3% linoleic acid). , Palmitic acid, stearic acid, etc. is 3%) and is a fatty acid. Commercially available products can be used as castor oil-based compounds. Commercially available products can be used as castor oil. Examples of such commercially available products include industrial No. 1 castor oil compound (trade name) manufactured by Toyokuni Oil Co., Ltd. and LAV (trade name) manufactured by Itoh Oil Chemicals Co., Ltd.

In the present invention, the castor oil derivative is based on castor oil, which is a kind of vegetable oil, and does not significantly change the structure and properties of the base castor oil such as introduction of functional groups, oxidation, reduction and replacement of atoms. A compound that has been modified.

Examples of the castor oil derivative include castor oil-based polyol, castor oil-based modified polyol, dehydrated castor oil, castor hardened oil, castor oil fatty acid, dehydrated castor oil fatty acid, 12-hydroxystearic acid, and castor oil fatty acid ester. ..

Commercially available products can be used as castor oil derivatives. As such commercial products, for example, Himashi Hardened Oil A (trade name), CO-FA (trade name), DCO-FA (trade name), Rick Sizer S4 (trade name), Rick Sizer C of Ito Oil Co., Ltd. -101 (trade name), and Rick Sizer GR-310 (trade name), URIC H52, URIC AC-006; Brownon BR-410 (trade name), Brownon BR-410 (trade name) manufactured by Aoki Yushi Kogyo Co., Ltd. , Brownon BR-430 (trade name), Brownon BR-450 (trade name), Brownon CW-10 (trade name), Brownon RCW-20 (trade name), Brownon RCW-40 (trade name), Brownon RCW-50 (Product name), Blaunon RCW-60 (Product name); and Custer Wax A (Product name) manufactured by Nichiyu Co., Ltd., Newsizer 510R (Product name), Sakura stearate (Product name), Himashi hardened fatty acid (Product name) Product name), NAA-34 (product name), NAA-160 (product name), NAA-175 (product name), and the like.
Castor oil compounds can be used alone or in combination.

The laminating adhesive according to the embodiment of the present invention preferably contains 10 to 90 parts by mass of (C) rosin ester per 100 parts by mass in total of (C) rosin ester and (D) castor oil-based compound. It is more preferably contained in an amount of 20 to 90 parts by mass, particularly preferably 25 to 70 parts by mass, and most preferably 30 to 60 parts by mass. By blending the component (C) and the component (D) in the above ratio, the adhesive for laminating according to the embodiment of the present invention has further improved compatibility, better adhesive strength, and more suppressed increase in viscosity. Therefore, when the laminated film is manufactured, it is easier to attach the plurality of films, and the laminated film is less likely to generate air bubbles.

The laminating adhesive according to the embodiment of the present invention may contain other components such as various additives in addition to the components (A) to (D), if necessary. The other components are components generally contained in the laminating adhesive, and are not particularly limited as long as the laminating adhesive of the embodiment of the present invention can be obtained. Examples of other components include solvents, pigments, plasticizers (excluding the above-mentioned components (C) and (D)), catalysts, adhesion promoters, and the like.

"Pigments" include, for example, TiO ₂ , SiO ₂ , Fe ₂ O ₃ or similar oxides or nanopigments based on oxyhydrates. These pigments usually have a particle size of 500 nm or less, more preferably less than 100 nm.

"Plastic agents" include, for example, white oil, naphthenic mineral oil, paraffin hydrocarbon oil, polypropylene oligomers, polybutene oligomers, polyisoprene oligomers, hydride polyisoprene and / or polybutadiene oligomers, phthalates, adipates, benzoate esters, vegetable oils or animal oils. Examples of these derivatives can be given.
Vegetable oils, animal oils and derivatives thereof are generally used in foods and are considered to be safer. Therefore, considering the use of the laminating adhesive according to the embodiment of the present invention in the production of food packaging films. , More preferred.

Examples of the "catalyst" include tin catalysts (trimethyltin laurate, trimethyltin hydroxide, dibutyltin dilaurate, dibutyltin maleate, etc.), lead-based catalysts (lead oleate, lead naphthenate, lead octenoate, etc.). ), Other metal catalysts (naphthenic acid metal salts such as cobalt naphthenate, etc.), and amine-based catalysts, such as triethylenediamine, tetramethylethylenediamine, tetramethylhexylenediamine, diazabicycloalkenes, dialkylaminoalkylamines, etc. Can be exemplified.

Examples of the "adhesion promoter" include silane compounds. Known organic functional silanes such as (meth) acrylic oxy functional, epoxy functional, amine functional and non-reactive substituted silanes can be used as adhesion promoters. Examples are vinyltrialkoxysilane, alkyltrialkoxysilane, tetraalkoxysilane, 3-acrylicoxypropyltrialkoxysilane, 3-methacryloxypropyltrialkoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxy. Silane, 3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-glycidyloxymethyltrimethoxysilane, 3-glycidyloxymethyltriethoxysilane, 2-glycidyloxyethyl Trimethoxysilane and the like.
As an embodiment of the present invention, it is preferable to contain 0.1 to 5 parts by mass of the adhesion promoter with respect to 100 parts by mass (solid content) of the total mass of the adhesive.

As described above, the laminating adhesive according to the embodiment of the present invention can be produced by mixing the component (A), the component (B), the component (C) and the component (D). The laminating adhesive according to the embodiment of the present invention is a two-component laminate containing a first liquid containing the component (A) and a second liquid containing the components (B) to (D). It may be an adhesive for use, and a first liquid containing the components (A), (C) and (D) and a second liquid containing the component (B) are blended, and the second liquid containing the two liquids is blended. It may be an adhesive for mold laminating. In some cases, other components may be mixed. The first liquid and the second liquid can each contain other components as appropriate.
The laminating adhesive according to the embodiment of the present invention is a two-component laminate that is blended with a first liquid containing the component (A) and a second liquid containing the components (B) to (D), and contains the two liquids. Adhesives for use are more preferred.

The mixing method is not particularly limited as long as the laminating adhesive intended by the present invention can be obtained. The order in which the components are mixed is not particularly limited. The laminating adhesive according to the embodiment of the present invention can be produced without requiring a special mixing method, a special mixing order, or the like. The obtained laminating adhesive has a small decrease in adhesive strength to the film and adhesive strength over time.

Since the laminating adhesive of the embodiment of the present invention is usually applied to a film at 15 to 100 ° C., it should have a low viscosity in this temperature range. Considering the coatability, the viscosity of the adhesive for food packaging film is preferably 300 to 5000 mPas at 40 ° C. and 200 to 4000 mPas at 50 ° C. by (Blockfield viscometer).

When the viscosity of the laminating adhesive according to the embodiment of the present invention is within the above range, the laminating adhesive can be applied more uniformly to the film, so that the adhesive strength and the appearance of the film can be further improved.

The laminated film of the embodiment of the present invention is a laminated body manufactured by using the above-mentioned adhesive for laminating. The film used to form the laminate is not particularly limited as long as the laminate of the embodiment of the present invention can be obtained, but for example, a film in which a metal layer is formed on a plastic base material or a metal layer. Can be exemplified as a film in which is not formed.

When producing a laminated film, the laminating adhesive according to the embodiment of the present invention is applied to the film. As a coating method, for example, various methods such as a gravure coat, a wire bar coat, an air knife coat, a die coat, a lip coat, and a comma coat can be used.

Using the laminating adhesive of the embodiment of the present invention, a plurality of films can be bonded together to produce a laminating film. When applying a laminating adhesive to the film, the coating amount is preferably 0.5 to 10 g / ^{m 2,} more preferably 1 to 5 g / ^{m 2.}

The laminated film of the embodiment of the present invention is one in which a plurality of films are bonded with the above-mentioned adhesive. Examples of embodiments of the present invention are illustrated in FIGS. 1 and 2, but the present invention is not limited to these embodiments.

FIG. 1 schematically shows a cross section of a laminated film according to an embodiment of the present invention. The laminated film 10 is formed of two films and an adhesive 13 for a laminated film between them, and the two films 11 and 12 are bonded by the adhesive 13 for a laminated film. The films 11 and 12 may be made of the same material or different materials.

In FIG. 1, the two films 11 and 12 are bonded together, but three or more films may be bonded together.

A cross section of the laminated film of another embodiment of the present invention is schematically shown in FIG. In FIG. 2, a thin film 11a is formed between the film 11 and the adhesive for the laminated film 13. For example, when the film 11 is a plastic film, the form in which the metal thin film 11a is formed on the surface of the film 11 is shown. The metal thin film 11a can be formed on the surface of the plastic film 11 by, for example, vapor deposition, and the film 11 and the film 12 on which the metal thin film 11a is formed are attached via an adhesive 13 for a laminated film. The laminated film according to No. 2 can be obtained.

Examples of the metal to be vapor-deposited on the plastic film include aluminum, steel and copper. By subjecting the plastic film to a thin-film deposition process, it is possible to impart barrier properties to the film. As the vapor deposition material, silicon oxide, aluminum oxide and the like are used. The base material plastic film 11 may be transparent or may be colored in white, black, or the like.

As the film 12, for example, a plastic film made of polyvinyl chloride, polyester, fluororesin, acrylic resin or the like is used, but in order to impart heat resistance, weather resistance, rigidity, insulation and the like, a polyethylene terephthalate film and a polybutylene terephthalate are used. It is particularly preferable to use a film or the like. The films 11 and 12 may be transparent or colored.

The thin-film vapor-deposited thin film 11a and the film 12 of the film 11 are attached to each other by using the adhesive 13 for a laminated film according to the embodiment of the present invention, but the films 11 and 12 are often laminated by a dry laminating method. Therefore, the adhesive 13 for a laminated film is required to have excellent initial adhesion to the film at the time of laminating and excellent adhesiveness to the film after curing.

The laminated film of the embodiment of the present invention is used for producing various packaging bags and outdoor materials.
The packaging bag refers to a bag-shaped article obtained by processing a laminated film in order to contain food, detergent, shampoo, conditioner and the like. Examples of outdoor materials include wall materials, roofing materials, solar cell modules, window materials, outdoor flooring materials, lighting protection materials, automobile parts, and articles used outdoors such as signboards.
These packaging bags and outdoor materials take the form of including a laminated film in which a plurality of films are bonded.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but these Examples are merely one aspect of the present invention, and the present invention is not limited to these examples.
In the description of the examples, unless otherwise specified, the portion not considering the solvent is used as the standard of parts by mass and% by mass.

<Manufacturing of adhesive for laminating>
The components for producing the adhesive are shown below.
(A) Urethane prepolymer having an isocyanate group at the end (A1) Loctite LIOFOL LA7735 (Components: Polypropylene glycol and polymer of diethylene glycol and isocyanate monomer NCO mass%: 11.5 Henkel Japan Co., Ltd.)
(A2) Loctite LIOFOL LA7715 (Components: Polypropylene glycol and polymer of polyester polyol and isocyanate monomer NCO mass%: 13.8% Henkel Japan Ltd.)

(B) Polyol component (B1) EXCENOL1020 (polypropylene glycol, Mn: 1000, hydroxyl value 111 mgKOH / g AGC Co., Ltd.)
(B2) Sanniks GP1500 (polypropylene glycol trifunctional, Mn: 1500, hydroxyl value 111 mgKOH / g Sanyo Chemical Industries, Ltd.)
(B3) Praxel 220EB (polycaprolactone polyol, Mn: 2000, hydroxyl value 56 mgKOH / g, manufactured by Mitsubishi Chemical Corporation)
(B4) Sanniks GP400 (polypropylene glycol trifunctional, Mn: 400, hydroxyl value 365 mgKOH / g Sanyo Chemical Industries, Ltd.)
(B5) PEG1000 (polyethylene glycol, Mn: 1000, hydroxyl value 111 mgKOH / g NOF CORPORATION)

(C) Rosin ester (C1) KOMOTAC KB90H (unhydrogenated rosin ester, softening point 90 ° C., acid value 0-10 mgKOH / g, GUANDONG KOMO Co., Ltd.)
(C2) KOMOTAC KH100 (hydrogenated rosin ester, softening point 100 ° C., acid value 0 to 15 mgKOH / g, GUANDONG KOMO Co., Ltd.)
(C3) Foralyn 5020-F (Liquid hydrogenated rosin ester, Eastman Chemical Co., Ltd.)
(C'4) Quintone B170 (unhydrogenated C5 resin, softening point 70 ° C, ZEON CORPORATION)
(C'5) ARKON P90 (hydrogenated C9 resin, Arakawa Chemical Industry Co., Ltd.)

(D) Castor oil (D1) Industrial No. 1 castor oil compound (castor oil compound, Toyokuni Oil Co., Ltd.)
(D2) URIC H52 (castor oil-based polyol, Itoh Oil Chemicals Co., Ltd.)
(D'3) Diana Fresia S32 (paraffin oil, Idemitsu Kosan Co., Ltd.)
(D'4) Rice bran oil (rice oil, Bosoh Oil & Fat Co., Ltd.)

As shown in Tables 1 and 2, the components (A) to (D) were mixed to produce a laminating adhesive of Examples 1 to 9 and Comparative Examples 1 to 6. Specifically, the components (B) to (D) were mixed with the compositions (parts by mass) shown in Tables 1 and 2, and the mixture was stirred at 120 ° C. for 1 hour. After cooling the mixture, the component (A) was added to the mixture in the amounts shown in Tables 1 and 2. The mixture was stirred at 40 ° C. for 5 minutes to prepare a laminating adhesive.

<Manufacturing of laminated film>
The laminating adhesive of the example was applied to a PET film having a printed surface having a white solid printed portion and a plain printed portion on the printed surface side so that the solid content mass was 2 g / m ² . Another PET film having a surface on which aluminum was vapor-deposited was laminated on the surface (printed surface) to which the adhesive of the PET film was applied from the vapor-deposited surface side. Using a hand roller, pressure was applied so that air bubbles could escape from between the adhesive and the vapor-filmed surface as much as possible. Then, it was cured in the atmosphere of 40 degreeC for 24 hours, and the laminated film was obtained.

<Evaluation>
1. 1. Initial Viscosity Measurement Based on JAI7-1991, Method B, the initial viscosity of the laminating adhesive was measured with a Brookfield viscometer. Specifically, the viscosity at 40 ° C. was measured with a No. 27 rotor and a rotation speed of 1 rpm.
Immediately after preparing the adhesive for laminating, the above apparatus was set, and the viscosity 1 minute after the start of measurement (start of rotor rotation) was defined as the initial viscosity (also referred to as “η1”).

2. 2. Compatibility The components (B), (C) and (D) are mixed at the ratios shown in Tables 1 and 2, 50 g of this mixture is added to a 140 ml transparent bottle, and the mixture is placed in the bottle for 3 hours (40 ° C.). It was allowed to stand still and the presence or absence of separation was visually confirmed. The evaluation criteria are as follows.
◯: Separation is not recognized and it is uniform.
X: Separation was observed.

3. 3. Measurement of Adhesive Strength The above-mentioned laminated film after 24-hour curing is cut into a width of 15 mm in the TD direction, and a peeling test is performed using a tensile strength tester (Tencilon RTM-250 (trade name) manufactured by Orientec Co., Ltd.) to bond. The intensity was measured.
The peeling test was carried out under the conditions of a tensile speed of 300 mm / min and T-type peeling after allowing the laminated film to stand in a room temperature environment (23 ° C.) for 24 hours or more. The evaluation criteria are as follows. The peeled part was measured in both the white solid printed part and the plain part, and evaluated by the lower value of the measured value. The evaluation criteria are as follows.
◯: 1.5N / 15mm or more Δ: 0.8N / 15mm or more, less than 1.5N / 15mm ×: 0.8N / less than 15mm −: It is difficult to measure the adhesive strength due to poor compatibility.

4. Stability (pot life)
After preparing the adhesive, the viscosity at 40 ° C. was measured to evaluate the stability. The measurement conditions (method) are the same as the conditions (method) described in the above-mentioned initial viscosity measurement.
The viscosity 1 minute after the start of the measurement (η1) and the viscosity 30 minutes after the measurement of η1 (also referred to as “η2”) were measured. As for the viscosity after 30 minutes, the viscosity was measured 1 minute after the start of rotation of the rotor after standing at 40 ° C. for 30 minutes after measuring η1. The viscosity increase rate was calculated to evaluate the stability of the adhesive. Here, the viscosity increase rate means (η2 / η1) × 100. The evaluation criteria are as follows.
◯: Viscosity increase rate is less than 300% Δ: Viscosity increase rate is 300% or more, 400% or less ×: Viscosity increase rate is higher than 400% −: Stability is difficult to measure due to poor compatibility.

5. Appearance Evaluation The appearance of the above-mentioned laminated film after 24-hour curing was visually evaluated. The evaluation criteria are as follows.
○: There are few dots (air bubbles) △: The existence of dots (air bubbles) is known, but it is inconspicuous ×: Dots (air bubbles) are quite conspicuous or do not become an adhesive −: It is difficult to evaluate the appearance because of poor compatibility.

As shown in Table 1, the laminating adhesives of Examples 1 to 9 have excellent compatibility of the components (A) to (D), give a very high level of appearance to the film, and have a printed portion. It also has excellent adhesion to the film. Further, the laminating adhesives of Examples 1 to 9 have a low rate of increase in viscosity from the initial viscosity and are stable, and are uniformly applied to the film.
The laminating adhesive of the embodiment of the present invention can be sufficiently used as a laminating adhesive for food packaging bags whose appearance is required at a very high level.

On the other hand, as shown in Table 2, the laminated adhesives of Comparative Examples 1 and 2 do not contain the rosin ester, so that the compatibility is low and the adhesive does not function as an adhesive.
The laminated adhesives of Comparative Examples 3 and 4 do not contain castor oil-based compounds. The laminating adhesive of Comparative Example 3 has low compatibility and does not function as an adhesive. The laminating adhesive of Comparative Example 4 has no problem in compatibility, but the adhesive strength is too low.

In the laminated adhesives of Comparative Examples 5 and 6, the compounding ratio of the polyol and the rosin ester is not appropriate. The laminating adhesive of Comparative Example 5 is inferior in stability. In the laminating adhesive of Comparative Example 6, air bubbles are conspicuous in the laminating film, and the appearance of the film is inferior.

As described above, it has been demonstrated that the laminating adhesive according to the embodiment of the present invention has excellent compatibility, does not deteriorate the appearance of the film, has excellent adhesive strength, has good stability, and improves workability.

The laminating adhesive according to the embodiment of the present invention does not deteriorate the appearance of the films when the plurality of films are bonded, has excellent adhesive strength after curing, and is excellent in uniformity and turbidity prevention, and is suitable for various uses. It can be used.
In particular, it is suitable as an adhesive for a laminated film for packaging foods, detergents, shampoos, rinses and the like.

10 Laminated film 11 Film 11a Deposited thin film 12 Film 13 Adhesive layer

Claims (3)

It is obtained by blending (A) a urethane prepolymer having an isocyanate group at the end, (B) a polyol component, (C) a rosin ester, and (D) a castor oil-based compound.
A laminating adhesive containing 50 to 250 parts by mass of the component (C) per 100 parts by mass of the component (B). (B) The laminating adhesive according to claim 1, wherein the polyol contains a polyether polyol. A laminated film in which a plurality of films are bonded via the laminating adhesive according to claim 1 or 2.

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