Adhesive, laminated film using thereof and polyol composition for adhesive

Abstract

Provided are a solvent-free two-component type adhesive capable of guaranteeing a practical packaging property, with an excellent curing property and significantly shortening aging time, a laminated film using the same, and a polyol composition for an adhesive. An adhesive, characterized in comprising a polyisocyanate composition (X) containing a polyisocyanate (A), and a polyol composition (Y) containing a polyol (C) and a tertiary amine compound (B) having multiple hydroxyl groups, as necessary components.

Claims

1. An adhesive comprising: a polyisocyanate composition (X), having a viscosity at the time of coating of 1000 mPas or less, containing: a polyisocyanate (A), and a polyol composition (Y), having a viscosity at the time of coating of 1000 mPas or less, containing: a polyol (C) selected from the group consisting of a polyester polyol, a polyester urethane polyol, a polyether urethane polyol, a polyether polyol and a castor oil-based polyol, and a tertiary amine compound (B) having multiple hydroxyl groups.

2. The adhesive according to claim 1, wherein an amine value of the adhesive ranges from 0.5 to 40 mgKOH/g.

3. The adhesive according to claim 1, wherein the polyol composition (Y) has a mass ratio of from 10 to 150 when the polyisocyanate composition (X) is set as 100.

4. A laminated film, which is characterized in that, a cured adhesive is provided between a first base film and a second base film, and the adhesive is the one according to claim 1.

5. A polyol composition for an adhesive, having a viscosity at the time of coating of 1000 mPas or less, comprising: a polyol (C) selected from the group consisting of a polyester polyol, a polyester urethane polyol, a polyether urethane polyol, a polyether polyol and a castor oil-based polyol, and a tertiary amine compound (B) having multiple hydroxyl groups.

6. A method for producing a film for flexible packaging comprising: coating a polyisocyanate composition (X), having a viscosity at the time of coating of 1000 mPas or less, containing a polyisocyanate (A) on one base material; coating a polyol composition (Y), having a viscosity at the time of coating of 1000 mPas or less, containing a polyol (C) selected from the group consisting of a polyester polyol, a polyester urethane polyol, a polyether urethane polyol, a polyether polyol and a castor oil-based polyol, and a tertiary amine compound (B) having multiple hydroxyl groups on another base material; and laminating the one base material and another base material together.

7. The adhesive according to claim 1, further comprising an alicyclic amide compound.

8. The adhesive according to claim 7, wherein the mixing amount of the alicyclic amide compound is 0.1 to 5 parts by mass per 100 parts by mass of the polyol (C).

9. The method for producing a laminate for flexible packaging according to claim 6, wherein the polyol composition (Y) does not contain the polyisocyanate (A).

10. The method for producing a laminate for flexible packaging according to claim 6, wherein the coating amount of the polyisocyanate composition (X) is 0.5 to 3.0 g/m.sup.2 and the coating amount of the polyol composition (Y) is 0.5 to 3.0 g/m.sup.2.

Description

EXAMPLES

Production Example 1 [Synthesis of Polyisocyanate (A-1)]

(1) In a flask provided with an agitator, a thermometer and a nitrogen introducing pipe, 36 parts of 4′ 4-diphenylmethane diisocyanate and 19 parts of 2,4′-diphenylmethane diisocyanate were put into this reaction vessel, stirred at an atmosphere of nitrogen, and heated to 60° C. 11 Parts of polypropylene glycol (hereinafter abbreviated as “PPG”) with a number average molecular weight of 400, 22 parts of PPG with a number average molecular weight of 1000, and 11 parts of PPG with a number average molecular weight of 2000 were dropwise added for several times, and stirred for 5-6 hours to terminate the carbamation reaction. The resulting polyisoocyanate contained an NCO group in an amount of 13.5% and had a melt viscosity at 40° C. of 1500 mPa.Math.s. The polyisoocyanate hereinafter was abbreviated as “A-1”.

Examples 1-21 and Comparative Examples 1-9

(2) Adhesives were prepared according to the formulae in Tables 1, 2 and 3 and were evaluated as follows. The results were listed in Tables 1-3.

(3) (Method for Producing Film for Flexible Packaging)

(4) Films for flexible packaging were produced by production method (1) and production method (2).

(5) (Production Method 1)

(6) After the polyisocyanate composition (X) and the polyol composition (Y) were prepared into an adhesive according to the formulae disclosed in Tables 1-5, the adhesive was coated on a film A in such a coating amount that solid ingredients were about 2.0 g/m.sup.2, and the coated side of the film A was adhered to a film B with a laminating machine, thereby preparing a laminated film for measuring shear strength.

(7) (Production Method 2)

(8) A polyisocyanate composition (X) and a polyol composition (Y) were respectively prepared according to the formulae disclosed in Tables 1-5, and (X) was coated on a film A and (Y) was coated on a film B, followed by preparing a plastic film laminate by laminating the coated sides of the films A and B by using a nip roll (nip roll temperature: 50° C.). The coating amount of each of (X) and (Y) conformed to the mass ratios between (X) and (Y) in Tables 1-3, i.e., 2.0 g/m.sup.2 in total. The processing speed was 30 m/min

(9) (Methods of Evaluation)

(10) (Shear Strength)

(11) As film A and film B, polyethylene terephthalate films (hereinafter abbreviated as “PET film”) were used. Laminated films for measuring shear strength were prepared as per production method (1) and production method (2).

(12) The laminated film was cut into 10 mm-width strips, and then the strips were cut to open a split of 1 cm alternatively on the front and back surface along the width direction to prepare test pieces. The test pieces were then stretched using a tensile testing machine with a tensile speed of 5 mm/min at an atmosphere temperature of 25° C. at each separated period to measure the shear strength of adhesion parts. The unit of the shear strength was set as N/10 mm.

(13) To compare how much the aging time is shortened, laminated films were prepared to evaluate shear strength two hours later.

(14) 6: 40N or greater

(15) 5: 30-39N

(16) 4: 20-29N

(17) 3: 10-19N

(18) 2: 1-9N

(19) 1: 0.9N or less

(20) (Practical Packaging Property)

(21) As a film A, a biaxially oriented polypropylene film (hereinafter abbreviated as “OPP film”) was used, and as a film B, an aluminum deposited unstretched polypropylene film (hereinafter abbreviated as “VMCPP”) was used. Laminated films for measuring a practical packaging property were prepared as per production method (1) and production method (2).

(22) This laminated film was aged for 3 days at 40° C., so that the adhesive coating was cured, and then a practical packaging property was evaluated.

(23) The test was conducted with a Gelbo Flex tester (a Gelbo Flex tester equipped with a BE-1006 thermostat, supplied by TESTER SANGYO CO., LTD.) in accordance with ASTMF392 under the conditions of a torsion angle of 440° and 1000 times of bends.

(24) The evaluation was based on numbers of pinholes and delaminations within a scale of 10 cm.sup.2.

(25) 6: occurrence number 0

(26) 5: occurrence number 1 or 2

(27) 4: occurrence number 3-5

(28) 3: occurrence number 6-8

(29) 2: occurrence number 9-11

(30) 1: occurrence number 12 or greater

(31) TABLE-US-00001 TABLE 1 Example Example Example Example Example Example Example Example Example 1 2 3 4 5 6 7 8 9 Formula Polyisocyanate composition (X) Polyisocyanate (A) (A-1) 55.0 55.0 61.0 61.0 65.0 65.0 76.0 90.0 70.0 Polyol composition (Y) Polyol (C) PPG-2000 31.0 38.0 25.0 32.0 21.0 28.0 16.0 Castor oil 2.0 23.0 HA-380B HA-700B Tertiary amine ED-500 compound (B) TE-360 14.0 7.0 14.0 7.0 14.0 7.0 8.0 8.0 7.0 having multiple hydroxyl groups Tertiary amine TEA compound DEA Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Melt viscosity at 40° C. of (X) 1500 1500 1500 1500 1500 1500 1500 1500 1500 (mPa .Math. s) Melt viscosity at 40° C. of (Y) 137 144 135 143 134 142 136 137 217 (mPa .Math. s) Amine value in (X) + (Y) 17.5 8.7 17.5 8.7 17.5 8.7 10.0 10.0 8.7 (mgKOH/g) Mass ratio of (Y) when (X) 82 82 64 64 54 54 32 11 43 is set as 100 Evaluation results Production Shear 6 5 6 5 6 5 6 6 5 Method (1) strength Practical pack 6 5 6 5 6 5 5 5 5 aging property Production Shear 4 4 5 5 5 5 6 6 5 Method (2) strength Practical 5 5 5 5 5 5 6 6 5 packaging property

(32) TABLE-US-00002 TABLE 2 Example 10 Example 11 Example 12 Example 13 Example 14 Formula Polyisocyanate composition (X) Polyisocyanate (A) (A-1) 55.0 55.0 65.0 65.0 70.0 Polyol composition (Y) Polyol (C) PPG-2000 38.0 41.5 28.0 31.5 Castor oil 26.5 HA-380B HA-700B Tertiary amine compound (B) ED-500 7.0 3.5 7.0 3.5 3.5 having multiple hydroxyl TE-360 groups Tertiary amine compound TEA DEA Total 100.0 100.0 100.0 100.0 100.0 Melt viscosity at 40° C. of (X) (mPa .Math. s) 1500 1500 1500 1500 1500 Melt viscosity at 40° C. of (Y) (mPa .Math. s) 302 226 345 248 352 Amine value in (X) + (Y) (mgKOH/g) 175 8.7 17.5 8.7 8.7 Mass ratio of (Y) when (X) is set as 100 82 82 54 54 43 Evaluation results Production Method (1) Shear 5 5 5 5 5 strength Practical 5 5 5 5 5 packaging property Production Method (2) Shear 4 4 5 5 5 strength Practical 5 5 5 5 5 packaging property

(33) TABLE-US-00003 TABLE 3 Example Example Example Example Example Example Example 15 16 17 18 19 20 21 Formula Polyisocyanate composition (X) Polyisocyanate (A) (A-1) 70.0 70.0 70.0 70.0 70.0 65.0 65.0 Polyol composition (Y) Polyol (C) PPG-2000 13.0 20.0 15.0 Castor oil 29.5 28.0 10.0 HA-380B 31.5 HA-700B 31.5 Tertiary amine ED-500 0.5 2.0 7.0 10.0 15.0 3.5 3.5 compound (B) TE-360 having multiple hydroxyl groups Tertiary amine TEA compound DEA Total 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Melt viscosity at 40° C. of (X) 1500 1500 1500 1500 1500 1500 1500 (mPa .Math. s) Melt viscosity at 40° C. of (Y) 265 308 411 475 638 1013 4500 (mPa .Math. s) Amine value in (X) + (Y) 1.2 5.0 17.5 24.9 37.4 8.7 8.7 (mgKOH/g) Mass ratio of (Y) when (X) 43 43 43 43 43 54 54 is set as 100 Evaluation results Production Shear 4 5 5 5 5 5 5 Method (1) strength Practical 4 5 5 5 4 5 5 packaging property Production Shear 4 5 5 5 4 4 4 Method (2) strength Practical 4 5 5 5 4 5 4 packaging property

(34) TABLE-US-00004 TABLE 4 Comparative Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 4 Example 5 Formula Polyisocyanate composition (X) Polyisocyanate (A) (A-1) 40.0 65.0 40.0 65.0 65.0 Polyol composition (Y) Polyol (C) PPG-2000 60.0 58.5 Castor oil 35.0 33.5 32.0 HA-380B HA-700B Tertiary amine compound (B) ED-500 having multiple hydroxyl TE-360 0.0 0.0 groups Tertiary amine compound TEA 1.5 1.5 3.0 DEA Total 100.0 100.0 100.0 100.0 100.0 Melt viscosity at 40° C. of (X) (mPa .Math. s) 1500 1500 1500 1500 1500 Melt viscosity at 40° C. of (Y) (mPa .Math. s) 150 250 147 241 231 Amine value in (X) + (Y) (mgKOH/g) 0.0 0.0 8.3 8.3 16.7 Mass ratio of (Y) when (X) is set as 100 150 54 150 54 54 Evaluation results Production Method (1) Shear 1 1 1 1 2 strength Practical 1 2 1 2 2 packaging property Production Method (2) Shear 1 1 1 2 2 strength Practical 1 2 1 2 2 packaging property

(35) TABLE-US-00005 TABLE 5 Comparative Comparative Comparative Comparative Example 6 Example 7 Example 8 Example 9 Formula Polyisocyanate composition (X) Polyisocyanate (A) (A-1) 40.0 65.0 65.0 90.0 Polyol composition (Y) Polyol (C) PPG-2000 59.6 Castor oil 33.9 32.8 HA-380B HA-700B Tertiary amine compound (B) ED-500 10.0 having multiple hydroxyl TE-360 groups Tertiary amine compound TEA DEA 0.4 1.1 2.2 Total 100.0 100.0 100.0 100.0 Melt viscosity at 40° C. of (X) (mPa .Math. s) 1500 1500 1500 1500 Melt viscosity at 40° C. of (Y) (mPa .Math. s) 149 243 236 1125 Amine value in (X) + (Y) (mgKOH/g) 3.1 8.4 16.9 24.9 Mass ratio of (Y) when (X) is set as 100 150 54 54 11 Evaluation results Production Method (1) Shear 1 1 2 5 strength Practical 1 2 2 2 packaging property Production Method (2) Shear 1 1 2 5 strength Practical 1 2 2 2 packaging property

(36) Abbreviations in Tables 1-5 are listed as follows: PPG-2000: polypropylene glycol (manufactured by Mitsui Chemicals Polyurethanes Co., Ltd., having a number average molecular weight of about 2000, a hydroxyl value of 55.2 mgKOH/g, a melt viscosity at 40° C. of 150 mPa.Math.s) Castor oil: refined castor oil (manufactured by ITOH Oil Chemicals Co., Ltd., having a hydroxyl value of 160.5 mgKOH/g, a melt viscosity at 40° C. of 250 mPa.Math.s) HA-380B: polyether urethane polyol (manufactured by DIC Co., Ltd., having a hydroxyl value of 91.0 mgKOH/g, a melt viscosity at 40° C. of 1,000 mPa.Math.s) HA-700B: polyester polyol (manufactured by DIC Co., Ltd., having a hydroxyl value of 130.0 mgKOH/g, a melt viscosity at 40° C. of 5000 mPa.Math.s) TEA: trimethylamine (manufactured by Daicel Corporation) DEA: diethylamine (manufactured by Daicel Corporation) ED-500: polypropylene glycol ethylenediamine ether TE-360: Triethanolamine, propoxylated

(37) According to the above results, by comprising a tertiary amine compound (B) having multiple hydroxyl groups, Examples 1-21 began to exhibit shear strength earlier, and had a practical packaging property being good. That is, it could be said that Examples 1-21 could ensure a practical packaging property and exhibit excellent curing property, and could significantly shorten aging time. Comparative Examples 1-2, as a composition excluding an amine compound, exhibited apparently low shear strength and practical packaging property. Comparative Examples 3-5, as a composition to which a tertiary amine was added, exhibited obviously low shear strength and practical packaging property that are similar to Comparative Examples 1-2. Comparative Examples 6-8, as a composition to which the secondary amine was added, exhibited obviously low shear strength and practical packaging property that are similar to Comparative Examples 1 and 2. In Comparative Example 9, the polyol consisted only of a tertiary amine compound (B) having multiple hydroxyl groups so that it exhibited shear strength as earlier as the Examples did, but its practical packaging property was poor.