JP5177149B2 - Adhesive composition and heat-fusible member using the same - Google Patents

Description

  The present invention relates to an adhesive composition and a heat-fusible member using the adhesive composition. More specifically, an adhesive composition having excellent adhesion, hot water resistance, chemical resistance, and the like, and useful for bonding a polyolefin resin molded article such as a polyolefin resin film and other members, and the adhesive composition It is related with the heat-fusible member formed by joining metal foil, such as aluminum foil, and a heat-fusible resin film.

  Conventionally, various adhesive compositions have been proposed for joining a molded body made of a polyolefin resin having poor adhesion to other members. For example, the main component is a resin composition obtained by reacting a chlorinated polyolefin, a specific resin having an isocyanate functional group at the terminal, and a polyurethane resin containing at least one free isocyanate group with a chain extender. Binders for adhesives and the like are known (for example, see Patent Document 1). Also known is a hot melt adhesive containing a predetermined amount of a base polymer such as polyethylene, an ethylene / (meth) acrylate copolymer, a tackifier, and a modified polyolefin obtained by graft copolymerizing a styrene monomer with a polyolefin. (For example, see Patent Document 2).

  Furthermore, an adhesive composition comprising a polyester-based urethane having an isocyanate group, a chloroprene rubber, a polyisocyanate, a halogenating agent and 2-ethylhexoates is known (for example, see Patent Document 3). Further, a liquid composition in which a carboxyl group-containing thermoplastic elastomer, a polyolefin polyol and a tackifier are dissolved or dispersed in an organic solvent, and an adhesive composition comprising a polyfunctional isocyanate are known (see, for example, Patent Document 4). .)

JP-A-8-225629 JP-A-6-228529 Japanese Patent Laid-Open No. 5-140529 WO2004 / 041954

  The binder for adhesives described in Patent Document 1 improves gasoline resistance, weather resistance, moisture resistance, etc. when a coating film is formed, for example, even if it is a polyolefin resin that is difficult to paint. It is explained that it can be made. However, since chlorinated polyolefin is contained, the use etc. may be restricted from the viewpoint of environmental considerations. Moreover, although the hot melt adhesive described in Patent Document 2 can be used as a polyolefin resin depending on the type of the base polymer, it cannot be said to have sufficient heat resistance because it is a hot melt type. Furthermore, although it has been described that good workability is maintained because it has an appropriate viscosity, it cannot be applied to the film surface etc. thinly and at high speed compared to the solvent type, and industrial productivity In addition, there is a problem that it is inferior in mass productivity.

  Moreover, in the adhesive composition described in Patent Document 3, since polyester-based urethane is used, it can be firmly bonded to a polyolefin-based material without performing pretreatment such as corona discharge treatment. Has been. However, polyester-based urethane is easily hydrolyzed, inferior in durability, chemical resistance, and the like, and has a high water absorption rate, and therefore inferior in water resistance (moisture permeability). Furthermore, the adhesive composition described in Patent Document 4 is described as having high initial adhesive strength and final adhesive strength and excellent adhesion durability in the adhesion of polyolefin-based resins. However, in this adhesive composition, there is no crystallinity or at least low crystallinity in view of the composition, so that it is easily attacked by the solvent, and the adhesive layer easily swells when contacted with the solvent. There is a problem that the adhesive strength is lowered.

  The present invention has been made in view of the above-described conventional problems, and can be bonded with sufficient strength when used for bonding a polyolefin material that is inherently inferior in adhesiveness, and is resistant to warm water and chemicals. An adhesive composition that is excellent in properties and useful as an adhesive for polyolefin materials, and a metal foil such as an aluminum foil and a heat-fusible resin film such as a polyolefin resin film are joined by this adhesive composition An object is to provide a heat-fusible member.

The present invention is as follows.
1. An organic solvent, a polyolefin resin having a carboxyl group dissolved or dispersed in the organic solvent, and a polyfunctional isocyanate compound contained in the organic solvent, wherein the polyfunctional isocyanate compound is contained in one molecule. A modified isocyanate compound having three or more isocyanate groups, which is an adhesive composition used for bonding a polyolefin material , wherein the polyolefin resin is obtained by graft polymerization of an ethylenically unsaturated carboxylic acid or its anhydride to a polyolefin. Modified polyolefin resin, and at least one of a copolymer resin of an olefin monomer and an ethylenically unsaturated carboxylic acid, the melting energy of the polyolefin resin measured in accordance with JIS K 7121 is 5 to 15 mJ / mg, The organic solvent and the polyolefin resin Total is 100% by weight, the polyolefin resin is 10 to 20 wt%, moisture permeability, as measured in accordance with JIS Z 0208 of the adhesive composition is in 10~50g ^/ m 2 ^/ 24h And an adhesive composition characterized by being used for joining a metal foil and a heat-fusible resin film layer .
2. The content of the carboxyl group contained in the polyolefin resin having a carboxyl group is from 0.10 to 0.70 mmol per 1 g of the polyolefin resin having a carboxyl group. The adhesive composition described in 1.
3. 1. The equivalent ratio (NCO / OH) between the isocyanate group (NCO) of the polyfunctional isocyanate compound and the hydroxyl group (OH) constituting the carboxyl group is 1.0 to 10.0. Or 2 . The adhesive composition described in 1.
4). Above 1. Thru 3 . An adhesive layer formed by curing the adhesive composition according to any one of the above, a metal foil bonded to one surface of the adhesive layer, and heat bonded to the other surface of the adhesive layer A heat-fusible member comprising: a fusible resin film layer.

The adhesive composition of the present invention is suitable for adhesion between a polyolefin resin molded article such as a polyolefin resin film and other members, for example, adhesion between a film made of a resin other than a polyolefin resin and a polyolefin resin film, and after curing. The adhesive layer has excellent hot water resistance, chemical resistance, and the like. When this adhesive composition is used, for example, in a container for medical fluids such as salt water resistance and infusion, such as when used for building materials and exterior products of buildings, especially building materials of buildings in the beach area, etc. It has excellent anti-electrolytic properties and corrosion resistance when used in parts of vehicles traveling on roads where snow melting agents are spread, and is useful in various industrial fields such as architecture, medical care, and automobiles.
When the carboxyl group content in the polyolefin resin having a carboxyl group is 0.10 to 0.70 mmol per 1 g of the polyolefin resin, the hydrophilicity is suppressed, and the adhesive composition is made of a polyolefin resin film or the like. When used for bonding a sealed container or the like, it is possible to suppress moisture from entering.
Furthermore , when the equivalent ratio (NCO / OH) of the isocyanate group (NCO) of the polyfunctional isocyanate compound to the hydroxyl group (OH) constituting the carboxyl group is 1.0 to 10.0, It can be improved further.
According to the heat-fusible member of the present invention, when the heat-fusible member is used as a sealed container for containing food, medicine, etc., moisture can be prevented from entering and contents can be prevented from being altered. can do.

It is the figure which looked at the heat-fusible member from the diagonal direction, and is a typical perspective view for demonstrating a cross section collectively.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1; Thermally fusible member, 11; Thermally fusible resin film layer, 12; Adhesive layer, 13; Metal foil (aluminum foil), 14; Resin layer.

The present invention will be described in detail below.
[1] Adhesive composition The adhesive composition of the present invention comprises an organic solvent, a polyolefin resin having a carboxyl group dissolved or dispersed in the organic solvent, and a polyfunctional isocyanate compound, and is a polyfunctional isocyanate. The compound is a modified isocyanate compound having three or more isocyanate groups in one molecule, and is an adhesive composition used for bonding a polyolefin material . The polyolefin resin is an ethylenically unsaturated carboxylic acid or its anhydride. And at least one of a modified polyolefin resin obtained by graft polymerization of a product and a copolymer resin of an olefin monomer and an ethylenically unsaturated carboxylic acid, and the melting energy of the polyolefin resin measured in accordance with JIS K 7121 is 5 to 15 mJ / mg, organic solvent and polyolefin resin Total is 100% by weight, the polyolefin resin is 10 to 20 wt%, moisture permeability, as measured in accordance with JIS Z 0208 of the adhesive composition is a 10~50g ^/ m 2 ^/ 24h, Used for joining the metal foil and the heat-fusible resin film layer .

(1) Polyolefin resin having a carboxyl group The above-mentioned “polyolefin resin having a carboxyl group” (hereinafter referred to as “polyolefin resin”) is a modified polyolefin obtained by graft-polymerizing an ethylenically unsaturated carboxylic acid or its anhydride to a polyolefin. Resins and copolymer resins of olefin monomers and ethylenically unsaturated carboxylic acids are used . Examples of polyolefins include homopolymers or copolymers of olefin monomers such as ethylene, propylene, and butene, and copolymers of these olefin monomers with dicyclopentadiene, 4-methylpentene-1, vinyl acetate, and the like. Can be used. Examples of the ethylenically unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid, and the like. Maleic acid is preferred from the standpoint of properties after curing and cost. These ethylenically unsaturated carboxylic acids may be used alone or in combination of two or more. The polyolefin resin is preferably a resin obtained by modifying a propylene homopolymer or a copolymer with ethylene, particularly a resin obtained by modifying a propylene homopolymer.

The melting energy measured in accordance with JIS K7121 of polyolefin resin is 5 to 15 mJ / mg. A melting energy of 5 to 15 mJ / mg is preferable because it can be used as an adhesive composition having excellent solubility in an organic solvent and sufficient adhesion durability such as warm water resistance and chemical resistance. . Further, this polyolefin resin has the melting energy described above and has a melting temperature of 80 ° C. or lower, particularly 60 to 80 ° C. If it is such a polyolefin resin, it can be set as the adhesive composition which is excellent in low-temperature adhesiveness, and has adhesive durability, such as warm water resistance and chemical resistance with sufficient adhesive layer after hardening.

Furthermore, although content of the carboxyl group in polyolefin resin is not specifically limited, It is preferable that it is 0.10-0.70 mmol per g of polyolefin resin. This content is particularly preferably 0.15 to 0.24 mmol. If the content of the carboxyl group is 0.10 to 0.70 mmol, the affinity for moisture does not become too high, and the adhesive composition is used for forming a sealed container or the like that contains food, medicine, etc. When used as the adhesive layer of the fusible member, moisture permeation can be sufficiently suppressed.
The carboxyl group content can be obtained as a value per gram of resin by dividing the acid content in the polyolefin resin calculated from the calibration curve of the infrared spectrum by the formula amount (45) of the carboxyl group.

(2) Organic solvent The “organic solvent” is not particularly limited as long as it can dissolve or disperse the polyolefin resin, but is preferably a solvent capable of dissolving more polyolefin resin. Moreover, this organic solvent is preferably an organic solvent that can be easily volatilized and removed from the adhesive composition by heating or the like. Examples of such organic solvents include aromatic organic solvents such as toluene and xylene, aliphatic organic solvents such as n-hexane, alicyclic organic solvents such as cyclohexane and methylcyclohexane, and ketone organics such as methyl ethyl ketone. A solvent or the like can be used. These organic solvents may be used alone or in combination of two or more.

Mass ratio of organic solvent and the polyolefin resin is preferably more polyolefin resin is a fraction which is soluble in an organic solvent, it is more preferable that the polyolefin resin the total amount is dissolved. This mass ratio can be set according to the type of each of the organic solvent and the polyolefin resin, and the polyolefin resin is 10 to 20% by mass when the total of the organic solvent and the polyolefin resin is 100% by mass. With such a mass ratio, more polyolefin resin can be dissolved easily.
The fact that the total amount of polyolefin resin is dissolved means that an adhesive composition (resin concentration: 20% by mass) is coated on a film such as polyethylene terephthalate with a bar coater to form a coating film having a thickness of 150 to 200 μm. (The thickness of the coating after drying the coating is 30 to 40 μm), and the surface roughness of this coating can be determined by 50 μm or less. The surface roughness of the coating film can be measured by a stylus type surface roughness meter defined in JIS B0651.

(3) Polyfunctional isocyanate compound The “polyfunctional isocyanate compound” has an action of reacting with a polyolefin resin to cure the adhesive composition. As this polyfunctional isocyanate compound, it is possible to use a modified product obtained by adduct-modifying a compound such as toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate or the like with an isocyanurate-modified, burette-modified, or a polyhydric alcohol such as trimethylolpropane. it can. These polyfunctional isocyanate compounds may be used alone or in combination of two or more. Also as this polyfunctional isocyanate compound, the polyfunctional isocyanate compound which melt | dissolves in the organic solvent described in said (2) is used normally.

  The polyfunctional isocyanate compound is a modified isocyanate compound having three or more isocyanate groups in one molecule. As a commercial product modified with isocyanurate, the product name “Coloneto HX” manufactured by Nippon Polyurethane Industry Co., Ltd., Asahi Kasei Chemicals Corporation Product name “Duranate TPA-100” manufactured by Mitsui Takeda Chemical Co., Ltd., and “Takenate D-170N” are examples. In addition, as a commercial product modified by burette, the trade name “Takenate D-165NN” manufactured by Mitsui Takeda Chemical Co., Ltd., and as a commercial product modified by trimethylolpropane adduct, the product name “Coronate L” manufactured by Nippon Polyurethane Industry Co., Ltd., Mitsui Trade name “Takenet D-102”, “Takenate D-140N” manufactured by Takeda Chemical Co.

  The mass ratio of the polyolefin resin and the polyfunctional isocyanate compound is not particularly limited, but the equivalent ratio of the isocyanate group (NCO) of the polyfunctional isocyanate compound and the hydroxyl group (OH) constituting the carboxyl group of the polyolefin resin ( NCO / OH) is preferably in a mass ratio of 1.0 to 10.0. The equivalent ratio is 1.5 to 10.0, particularly 1.8 to 9.0, and more preferably 3.5 to 9.0. When the equivalent ratio is 1.0 to 10.0, an adhesive composition having excellent initial adhesiveness can be obtained, and the adhesive has a sufficient crosslinking density and excellent flexibility and the like. A layer can be formed.

(4) Other components In the adhesive composition, in addition to the polyolefin resin and the polyfunctional isocyanate compound, a reaction accelerator is blended, tackifying resin, non-acid-modified thermoplastic elastomer, non-acid-modified heat. A plastic resin, a plasticizer, etc. can also be contained.
(A) Reaction accelerator A reaction accelerator is blended in order to accelerate the reaction between the polyolefin resin and the polyfunctional isocyanate compound. Examples of the reaction accelerator include various organotin compounds and tertiary amines. Only 1 type of reaction accelerator may be used, 2 or more types may be used together, and an organotin compound and a tertiary amine can also be used together.

(B) Tackifiers Examples of tackifiers include polyterpene resins, rosin resins, aliphatic petroleum resins, alicyclic petroleum resins, copolymer petroleum resins, and hydrogenated petroleum resins. Examples of the polyterpene resin include α-pinene polymers, β-pinene polymers, and copolymers thereof with phenol or bisphenol A. For example, trade names “YS Resin PX”, “Yasuhara Chemical Co., Ltd.” Commercial products such as “YS Resin A” and “YS Polyster T” can be used. Examples of the rosin resin include natural rosin, polymerized rosin, and ester derivatives thereof. For example, commercially available products such as trade names “Pencel D” and “Superester A” manufactured by Arakawa Chemical Industries, Ltd. can be used. . Aliphatic petroleum resin is also referred to as C ₅ resin, typically a resin which is synthesized from C ₅ fraction of petroleum, Tonex Co., Ltd. under the trade name "Escorez", Nippon Zeon Co., Ltd. under the trade name "Quinton", Goodyear Commercial products such as a trade name “Wingtack” manufactured by the company can be used. Alicyclic petroleum resins said to be C ₉ resins, generally a resin synthesized from C ₉ fraction of the oil, it can be used by Maruzen Petrochemical Co., Ltd. under the trade name commercial products such as "MARUKAREZ". The copolymerized petroleum resin is also referred to as a C ₅ / C ₉ copolymer resin, and commercially available products such as “Toho High Resin” manufactured by Toho Chemical Industry Co., Ltd. can be used. Hydrogenated hydrocarbon resins are generally produced by hydrogenation of the above-mentioned various petroleum resins. Trade names “Ester gum H” and “Arcon” manufactured by Arakawa Chemical Industries, Ltd. and “Clearon” manufactured by Yashara Chemical Co., Ltd. The trade name “Escollet” manufactured by Tonex Co., Ltd. can be used. These tackifiers may be used alone or in combination of two or more.

(C) Others Examples of the thermoplastic elastomer that is not acid-modified include SEBS and SEPS. The thermoplastic resin that is not acid-modified is preferably an ethylene-vinyl acetate copolymer resin, an ethylene-ethyl acrylate copolymer resin, a wax, or the like. Furthermore, the plasticizer is preferably a liquid rubber such as polyisoprene or polybutene, or process oil.
The content of the other components (a) to (c) is 70% by mass or less, particularly 60 to 10% by mass, when the total of the polyolefin resin, the polyfunctional isocyanate compound and the other components is 100% by mass. Furthermore, it is preferable that it is 50-20 mass%. When the content of other components is 70% by mass or less, an adhesive composition having sufficient adhesion, hot water resistance, chemical resistance, and the like can be obtained.

The adhesive composition of the present invention can be used as an adhesive layer for a sealed container made of a resin film for containing foods, medicines and the like. For example, it can be used as an adhesive layer for joining a metal foil and a heat-fusible resin film. Thus, in the heat-fusible member having the metal foil, the adhesive layer, and the heat-fusible resin film layer, the moisture that has passed through the heat-fusible resin film further passes through the adhesive layer, When reaching the above, the peel strength at this interface may be lowered or peeled off. In order to suppress such strength reduction and peeling, the adhesive layer preferably has low moisture permeability. Therefore, the moisture permeability measured according to JIS Z 0208 of the adhesive composition is 10 to 50 g / m ² · 24 h. If the moisture permeability is 10 to 50 g / m ² · 24 h, moisture permeation can be sufficiently suppressed, and the decrease in the peel strength and the occurrence of peeling at the interface between the adhesive layer and the metal foil are sufficiently suppressed. be able to.

[2] Heat-fusible member As shown in FIG. 1, the heat-fusible member of the present invention is bonded to an adhesive layer formed by curing the adhesive composition of the present invention and one surface of the adhesive layer. A metal foil and a heat-fusible resin film layer bonded to the other surface of the adhesive layer are provided.

  The “adhesive layer 12” is obtained by applying the adhesive composition described in [1] above to at least one surface of the metal foil 13 and the resin film to be the heat-fusible resin film layer 11, and thereafter Then, the organic solvent can be removed, and then the metal foil 13 and the resin film can be formed by laminating the surfaces coated with the adhesive composition facing each other, heating and pressure bonding, and simultaneously heat melting. The wearing member 1 is formed. The thickness of the adhesive layer 12 is not particularly limited depending on the material and the like, but is preferably 1 to 20 μm, particularly preferably 2 to 10 μm. If the thickness of the adhesive layer 12 is 1 to 20 μm, it is easy to perform processing such as bending of the heat-fusible member. The adhesive composition is often applied to the surface of the metal foil 13, but is not particularly limited. The adhesive composition can be applied by an ordinary method, and for example, it can be applied using a bar coater, a gravure coater or the like. The conditions for heating and pressure bonding are not particularly limited, and are preferably set according to the respective materials of the metal foil 13 and the resin film to be the heat-fusible resin film layer 11 and the composition of the adhesive composition.

  The material of the “metal foil 13” is not particularly limited, but aluminum foil is usually used because of excellent workability. The thickness of the metal foil 13 is not particularly limited depending on the material or the like. For example, in the case of an aluminum foil, it is preferably 20 to 100 μm, particularly 20 to 80 μm, and more preferably 30 to 60 μm. If the thickness of the aluminum foil is 20 to 100 μm, the heat-fusible member 1 can be easily formed without being easily damaged. Moreover, in order to protect the metal foil 13 and to improve the appearance of a sealed container or the like, a resin layer 14 may be provided on the surface of the metal foil 13 opposite to the surface on which the adhesive layer 12 is formed. The material of this resin layer 14 is not specifically limited, It can be set as the resin layer 14 which consists of a polyamide resin, a polyester resin, etc. The thickness of the resin layer 14 is not particularly limited, and can be 30 to 60 μm, particularly 30 to 50 μm.

  The “heat-fusible resin film layer 11” can be formed using a polyolefin resin film. Furthermore, among the polyolefin resin films, a polypropylene film, particularly an unstretched polypropylene film with little dimensional change (shrinkage) at the time of heat fusion is more preferable. If it is the heat-fusible resin film layer 11 which consists of polyolefin resin films, it will be easy to heat-seal | fuse, and the predetermined location of the heat-sealable member 1 can be heat-sealed easily and with sufficient intensity | strength. The thickness of the heat-fusible resin film layer 11 is not particularly limited depending on the material and the like. For example, in the case of an unstretched polypropylene film, it is preferably 10 to 200 μm, particularly 20 to 100 μm, and more preferably 60 to 100 μm. . When the unstretched polypropylene film has a thickness of 10 to 200 μm, it is not easily damaged and can be a highly durable sealed container or the like.

Hereinafter, the present invention will be described specifically by way of examples.
[1] Production Example 1 of Adhesive Composition
170 g of organic solvent (mixed solvent of methylcyclohexane: methylethylketone = 8: 2 by mass ratio) was put into a 500 ml flask equipped with a condenser and a stirrer, and then polyolefin resin (maleic acid-modified polypropylene, Nippon Paper Chemicals) Product name “S-5212” (melting energy: 5 mJ / mg, melting temperature: 77 ° C., acid value: 10 KOH mg / g, carboxyl group content: 0.33 mmol / g, acid content: 1.5 mass% Next, the temperature in the flask was set to 50 ° C. and heated and stirred for 3 hours to dissolve the resin, and then cooled to room temperature, and dibutyltin dilaurate was added to the resin as 100 ppm as a reaction accelerator. Added, the solution viscosity is 30 mPa · s (25 ° C.), and the resin concentration is 15% by mass of light yellow liquid. It was obtained Chakuzai.
Next, this liquid adhesive is used as a main agent, and a polyfunctional isocyanate compound (trade name “Duranate TPA-100” manufactured by Asahi Kasei Chemicals Co., Ltd.) is blended with this main agent so that the equivalent ratio (NCO / OH) is 1.8. To obtain an adhesive composition. This adhesive composition was subjected to the preparation of test pieces described later within 1 hour after blending the polyfunctional isocyanate compound. The composition and the like are shown in Table 1.

Experimental example 2
An adhesive composition was obtained in the same manner as in Experimental Example 1 except that the amount of the polyfunctional isocyanate compound was increased as shown in Table 1 so that the equivalent ratio was 5.0.
Experimental example 3
160 g of organic solvent, manufactured by Nippon Paper Chemical Co., Ltd. as a polyolefin resin, trade name “S-5183” (maleic acid-modified polypropylene, melting energy: 10 mJ / mg, melting temperature: 67 ° C., acid value: 13 KOH mg / g, carboxyl group Content: 0.44 mmol / g, acid content: 2.0% by mass) 26.7 g, and Arakawa Chemical Co., Ltd., trade name “Arcon P-100” (completely hydrogenated C9 resin, softening point) as a tackifier ; 100 ° C), and an adhesive composition was obtained in the same manner as in Experimental Example 1, except that the polyfunctional isocyanate compound was added as shown in Table 1 so that the equivalent ratio was 2.5.
Experimental Example 4
An adhesive composition was obtained in the same manner as in Experimental Example 1 except that the amount of the polyfunctional isocyanate compound was increased as shown in Table 1 so that the equivalent ratio was 9.0.

Experimental Example 5
As shown in Table 2, an adhesive composition was obtained in the same manner as in Experimental Example 1 except that no polyfunctional isocyanate compound was blended.
Experimental Example 6
Polyolefin resin manufactured by Sanyo Chemical Industries, trade name “Yumex 1010” (maleic acid-modified polypropylene, melting energy: 52 mJ / mg, melting temperature: 137 ° C., acid value: 52 KOH mg / g, carboxyl group content: 2.22 mmol / g, acid content; 10% by mass), and the amount was increased, and the adhesive composition was the same as in Experimental Example 1 except that the polyfunctional isocyanate compound was blended in an equivalent ratio of 2.0 as shown in Table 2. I got a thing.
Experimental Example 7
In place of maleic acid-modified polypropylene, acid-modified SEBS (manufactured by Asahi Kasei Chemicals Corporation, trade name “Tuftec M-1913” (amorphous) was used, and the polyfunctional isocyanate compound had an equivalent ratio of 2.5 as shown in Table 2. An adhesive composition was obtained in the same manner as in Experimental Example 1 except that the blending amount was as follows.

[2] Performance evaluation (1) Viscosity The viscosity was measured at 25 ° C. using a B-type rotational viscometer.
(2) Moisture permeability The adhesive composition was applied to the release agent surface of the release paper using a bar coater so that the thickness after drying was 50 μm, and then the organic solvent was volatilized at room temperature. Subsequently, the test piece was aged for 5 days in a hot-air circulating oven set at 40 ° C., and measured according to JIS Z 0208.

(3) Peeling adhesive strength (A) Preparation of test piece The adhesive composition was applied to an aluminum foil having a thickness of 40 μm with a bar coater, and then housed in a hot-air circulating oven adjusted to 100 ° C. The organic solvent contained in the adhesive composition was removed by drying for 60 seconds to form an adhesive layer having a film thickness of 6 to 8 μm. Next, an unstretched polypropylene film having a thickness of 80 μm (hereinafter abbreviated as CPP) was bonded to the adhesive layer as a heat-fusible resin film, and bonded using a thermal inclination tester. At this time, the bonding conditions were a temperature of 80 ° C., a pressure of 0.3 MPa, and a pressure bonding time of 3 seconds. The adhesion area was 10 × 25 mm. Subsequently, this test piece was stored in a hot-air circulating oven adjusted to 40 ° C. and aged for 5 days.

(B) T peel adhesion strength (a) Normal state (initial)
After the aging was completed, the test piece was cut to a width of 15 mm, and the T peel adhesion strength (N / 15 mm) between the aluminum foil and the CPP was measured.
(B) After immersion in warm water The test piece cut to a width of 15 mm in (a) above was immersed in warm water at 85 ° C. for 7 days. After immersion, the substrate was washed with water at 23 ° C., and immediately after the washing, the T peel adhesion strength (N / 15 mm) between the aluminum foil and the CPP was measured.
The T peel adhesion strength was measured using a tensile tester (manufactured by Toyo Seiki Co., Ltd.) for both (a) and (b) at a temperature of 23 ° C. and a tensile speed of 100 mm / min.
The results are shown in Tables 1 and 2.

  According to the results of Table 1, in Experimental Examples 1 to 4 in which both the melting energy and the equivalent ratio (NCO / OH) of the acid-modified polypropylene are in the preferred range, both the initial and the peel adhesion strength after immersion in warm water are sufficiently large. It can be seen that it has both excellent adhesion and hot water resistance. In particular, in Experimental Example 2 with a larger equivalent ratio, it can be seen that the peel adhesion strength after immersion in warm water is large, and that it has better warm water resistance. Moreover, in Experimental Example 4 in which the equivalence ratio is larger, it can be seen that the peel adhesion strength at the initial stage and after immersion in warm water is larger, and particularly, it has excellent low-temperature adhesion and hot water resistance.

Moreover, according to the result of Table 2, in Experimental example 5 which does not contain a polyfunctional isocyanate compound, the peeling adhesive strength after warm water immersion is small, and warm water resistance is inferior. Furthermore, in Experimental Example 6 where the melting energy of the acid-modified polypropylene is excessive, the acid-modified polypropylene does not dissolve in the organic solvent, and thus the peel adhesion strength itself cannot be measured. Further, in Experimental Example 7 using amorphous acid-modified SEBS, it can be seen that both the initial peel strength after immersion in hot water and that after hot water immersion are small, and the adhesiveness and hot water resistance are poor.
In addition, according to the value of the moisture permeability of each adhesive composition of Experimental Examples 1 to 7, if this moisture permeability is 50 g / m ² · 24 h or less, it particularly affects the peel adhesion strength of the adhesive composition. It is understood that does not reach. Similarly, it can be seen that the viscosity of the adhesive composition does not particularly affect the peel adhesion strength.

Claims (4)

An organic solvent,
A polyolefin resin having a carboxyl group dissolved or dispersed in the organic solvent;
A polyfunctional isocyanate compound contained in the organic solvent, and the polyfunctional isocyanate compound is a modified isocyanate compound having three or more isocyanate groups in one molecule, and is used for adhesion of polyolefin materials. a composition,
The polyolefin resin is at least one of a modified polyolefin resin obtained by graft polymerization of an ethylenically unsaturated carboxylic acid or an anhydride thereof to a polyolefin, and a copolymer resin of an olefin monomer and an ethylenically unsaturated carboxylic acid,
The melting energy of the polyolefin resin measured according to JIS K 7121 is 5 to 15 mJ / mg,
When the total of the organic solvent and the polyolefin resin is 100% by mass, the polyolefin resin is 10 to 20% by mass,
Moisture permeability was measured according to JIS Z 0208 of the adhesive composition is a 10~50g ^/ m 2 ^/ 24h,
An adhesive composition used for joining a metal foil and a heat-fusible resin film layer .   The adhesive composition according to claim 1, wherein the content of the carboxyl group contained in the polyolefin resin having a carboxyl group is 0.10 to 0.70 mmol per 1 g of the polyolefin resin having the carboxyl group. And the polyfunctional isocyanate groups of the isocyanate compound has (NCO), in claim 1 or 2 equivalent ratio of the hydroxyl groups (OH) (NCO / OH) is 1.0 to 10.0 constituting a carboxyl group The adhesive composition as described. An adhesive layer formed by curing the adhesive composition according to any one of claims 1 to 3 ,
A metal foil bonded to one surface of the adhesive layer;
And a heat-fusible resin film layer bonded to the other surface of the adhesive layer.

Images