Hot Melt Adhesive for Polyolefin Films

Abstract

A hot-melt adhesive composition is disclosed. The hot melt adhesive comprises a) 25 to 95 wt %, preferably 50 to 85 wt % of at least one polyolefin-based polymer; b) 1 to 75 wt %, preferably 1 to 40 wt % of at least one tackifying resin; c) 0 to 15 wt % of at least one plasticizer; and d) 0 to 30 wt % of at least one additive and/or adjuvant selected from among stabilizers, adhesion promoters, fillers or pigments, waxes, and/or other polymers or combinations thereof,
characterized in that the at least one polyolefin-based polymer is a mixture of: a1) at least one first polyolefin-based polymer with a molecular weight M.sub.n of <10,000 g/mol in a quantity of 20 to 80 wt % with respect to the total quantity of polyolefin-based polymer, and a2) at least one second polyolefin-based polymer with a molecular weight M.sub.n of >10,000 g/mol in a quantity of 20 to 80 wt % with respect to the total quantity of polyolefin-based polymer. The adhesive is particularly useful for gluing polyolefin films, woven fabrics, or nonwoven fabrics. Also, methods for manufacturing packaging and fabric with the hot-melt adhesive above are disclosed.

Claims

1. A hot-melt adhesive comprising, a) 25 to 95 wt % of at least one polyolefin-based polymer; b) 1 to 75 wt % of at least one tackifying resin; c) 0 to 15 wt % of at least one plasticizer; and d) 0 to 30 wt % of at least one additive and/or adjuvant selected from stabilizers, adhesion promoters, fillers or pigments, waxes, (meth)acrylic acid esters, or combinations thereof, characterized in that the at least one polyolefin-based polymer is a mixture of: a1) at least one first polyolefin-based polymer with a molecular weight M.sub.n of <10,000 g/mol in a quantity of 20 to 80 wt % with respect to the total quantity of polyolefin-based polymer, and a2) at least one second polyolefin-based polymer with a molecular weight M.sub.n of >10,000 g/mol in a quantity of 20 to 80 wt % with respect to the total quantity of polyolefin-based polymer.

2. The hot-melt adhesive as set forth in claim 1, characterized in that the at least one polyolefin-based polymer is an atactic poly-α-olefin (APAO.

3. The hot-melt adhesive as set forth in claim 2, characterized in that the atactic poly-α-olefin is (i) a ethylene/α-olefin with propene, 1-butene, 1-hexene, 1-octene comonomers, or (ii) propylene/α-olefin with ethylene, 1-butene, 1-hexene, 1-octene, or comonomers.

4. The hot-melt adhesive as set forth in claim 1, characterized in that the at least one tackifying resin is a fully or partially hydrated hydrocarbon resin and/or at least one natural resin based on colophony or tall oil resin or a methyl, pentaerythritol, or glycerin ester thereof, with the at least one fully or partially hydrated hydrocarbon resin optionally containing a cycloaliphatic resin, an aromatically modified resin, a polyterpene, a terpene phenolic resin, a 1,3-pentadiene resin, a cyclopentadiene resin, a 2-methyl-2-butene copolymer, or a derivative of the above.

5. The hot-melt adhesive as set forth in claim 4, characterized in that the fully or partially hydrated hydrocarbon resin contains a cycloaliphatic resin, an aromatically modified resin, a polyterpene, a terpene phenolic resin, a 1,3-pentadiene resin, a cyclopentadiene resin, a 2-methyl-2-butene copolymer, or a derivative thereof.

6. The hot-melt adhesive as set forth in claim 1, characterized in that the plasticizer is selected from poly(iso)butylene and liquid or pasty hydrated hydrocarbons.

7. The hot-melt adhesive as set forth in claim 6, characterized in that the polyisobutylene has a molecular weight M.sub.w of less than 5,000 g/mol.

8. The hot-melt adhesive as set forth in claim 1, characterized in that the at least one additive and/or the adjuvant is a stabilizer.

9. The hot-melt adhesive as set forth in claim 1, characterized in that the hot-melt adhesive has a viscosity in the range from 500 to 100,000 mPas at 160° C., measured with a Brookfield CAP, spindle 8.

10. The hot-melt adhesive as set forth in claim 1, comprising, 50 to 85 wt % of at least one polyolefin-based polymer and 1 to 40 wt % of at least one tackifying resin.

11. An article comprising a substrate and the hot-melt adhesive of claim 1.

12. The article as set forth in claim 11, characterized in that the substrate is a polyolefin film, woven fabric or a nonwoven fabric.

13. The article as set forth in claim 11, characterized in that the polyolefin film is surface-treated with at least 80 wt % polyethylene (PE) or polypropylene (PP), based on the total weight of the polyolefin film.

14. The article as set forth in claim 11, which is a packaging bag, packaging pouch, glued woven fabric, glued nonwoven fabric.

15. A method for manufacturing a packaging comprising (1) preparing a plurality of polyolefin films, (2) partial-surface gluing at least two polyolefin films longitudinally and/or bottom gluing the hot-melt adhesive as set forth in claim 1.

16. A method for manufacturing a fabric comprising (1) preparing a woven fabric or nonwoven fabric, (2) partial-gluing or full-surface gluing the woven fabric or the nonwoven fabric with the hot-melt adhesive as set forth in claim 1.

Description

EXAMPLES

Example 1: Adhesive Formulation

[0055] In the following, the term “hydrocarbon resin” is also referred to as “HC resin.”

[0056] The glass transition temperature T.sub.g was determined according to DIN EN 1427.

[0057] The melt viscosity was determined according to DIN 53019.

[0058] The molecular weight M.sub.n was determined according to DIN 55672, as described above.

[0059] Adhesive compositions were prepared which contained the following components in relation to the composition:

TABLE-US-00001 Formulation 1: Poly-α-olefin (M.sub.n 5,000 g/mol; T.sub.g 96° C.; 70.0 wt % melt viscosity 2,500 mPas) Poly-α-olefin (M.sub.n 18,100 g/mol; T.sub.g 107° C.; 15.0 wt % melt viscosity 50,000 mPas) Escorez 5400 (DownMobil Chemical),  5.0 wt % cycloaliphatic HC resin Polybut 10 (Productos Uhpon), polyisobutylene  9.5 wt % Irganox 1010 (BASF SE), antioxidant  0.5 wt %

[0060] The product obtained in this way exhibited very good adhesion on polyolefin-based bag material in conjunction with a very high level of cohesion.

TABLE-US-00002 Formulation 2: Poly-α-olefin (M.sub.n 5,000 g/mol; T.sub.g 96° C.; 70.0 wt % melt viscosity 2,500 mPas) Poly-α-olefin (M.sub.n 18,100 g/mol; T.sub.g 107° C.; 15.0 wt % melt viscosity 50,000 mPas) Sylvatac RE 85 (Arizona Chemical), colophony  5.0 wt % glycerol ester Polybut 10 (Productos Uhpon) polyisobutylene  9.5 wt % Irganox 1010 (BASF SE), antioxidant  0.5 wt %

[0061] The product obtained in this way had even greater adhesion than formulation 1.

TABLE-US-00003 Formulation 3: Poly-α-olefin (M.sub.n 5,000 g/mol; T.sub.g 96° C.; 15.0 wt % melt viscosity 2,500 mPas) Poly-α-olefin (M.sub.n 18,100 g/mol; T.sub.g 107° C.; 40.0 wt % melt viscosity 50,000 mPas) Regalite S1100 (Eastman Chemical Company), 29.5 wt % cycloaliphatic HC resin Polybut 10 (Productos Uhpon), polyisobutylene 12.0 wt % Polybut 30 (Productos Uhpon), polyisobutylene  3.0 wt % Irganox 1010 (BASF SE), antioxidant 0.35 wt % Irganox PS 802 FL (BASF SE), antioxidant 0.15 wt %

[0062] This adhesive had a viscosity of about 11,300 mPas at 160° C. (Brookfield RVT spindle 21) and a softening point of 87.8/87.9° C. (ASTM E 28). With a 50 μm PET coating in a quantity of 40 g/m.sup.2 with a heating table/heating blade at 150° C. adhesive temperature, the adhesive exhibited an adhesive bond on steel and PE after 20 minutes of 31 and 15 N/25 mm, respectively, and of 33 and 32 N/25 mm on steel and glass, respectively, after 24 h. After regluing (130° C., 30 seconds, 5 kg/100 cm.sup.2), adhesive bonds on steel and PE and glass of 35 (70% adhesion failure) and 17 and 24 N/25 mm, respectively, were achieved after 24 h.

TABLE-US-00004 Formulation 4: Poly-α-olefin (M.sub.n 5,000 g/mol; T.sub.g 96° C.; 15.0 wt % melt viscosity 2,500 mPas) Poly-α-olefin (M.sub.n 18,100 g/mol; T.sub.g 107° C.; 35.0 wt % melt viscosity 50,000 mPas) Regalite R1010 (Eastman Chemical Company),  5.0 wt % cycloaliphatic HC resin Regalite S1100 (Eastman Chemical Company), 29.6 wt % cycloaliphatic HC resin Polybut 10 (Productos Uhpon), polyisobutylene 12.0 wt % Polybut 30 (Productos Uhpon), polyisobutylene  3.0 wt % Irganox 1010 (BASF SE), antioxidant 0.35 wt % Irganox PS 802 FL (BASF SE), antioxidant 0.15 wt %

[0063] This adhesive had a viscosity of about 7500 mPas at 160° C. (Brookfield RVT, spindle 21) and a softening point of 85.2/85.4° C. (ASTM E 28). With a 50 μm PET coating in a quantity of 40 g/m.sup.2 with a heating table/heating blade at 150° C. adhesive temperature, the adhesive exhibited an adhesive bond on steel and PE and glass after 20 minutes of 23 and 17 and 26 N/25 mm, respectively, and of 37 and 8 and 41 N/25 mm (50% adhesion failure) on steel and PE and glass, respectively, after 24 h. After regluing (130° C., 30 seconds, 5 kg/100 cm.sup.2), adhesive bonds on steel and PE and glass of 35 (80% adhesion failure) and 23 and 37 N/25 mm (80% cohesive failure), respectively, were achieved after 24 h.