Composition and method relating to a hot melt adhesive
View Patent ↗The invention includes a hot melt adhesive composition that includes at least one of an isotactic copolymer of butene-1 and a metallocene catalyzed propylene homopolymer, a tackifying resin, and, optionally, a wax. The adhesive composition initially exhibits adhesion quality and subsequently non-adhesion quality. The invention also includes methods of using the adhesive composition for temporarily bonding substrates.
1. A method of using a hot melt composition to temporarily adhesively bond a first substrate and a second substrate, the method comprising:
a) applying the composition to a first surface of the first substrate to create a first bonding surface; and
b) contacting the first bonding surface to the second substrate to form a bond,
the composition consisting essentially of metallocene catalyzed polypropylene homopolymer, tackifying resin, and wax, and
the composition exhibiting at least about 60% fiber tear after 10 minutes and no greater than about 20% fiber tear after 24 hours when tested according to at least one of the Median Coupon Test and the Modified Median Coupon Test.
2. The method of claim 1 , wherein the metallocene catalyzed polypropylene homopolymer has a heat of fusion of no greater than about 40 J/g.
3. The method of claim 1 , wherein the composition consists essentially of from about 20% by weight to about 80% by weight metallocene catalyzed polypropylene homopolymer, from about 5% by weight to about 70% by weight tackifying resin, and from about 5% by weight to about 60% by weight wax.
4. The method of claim 1 , wherein the composition further comprises a polymer other than a metallocene catalyzed polypropylene homopolymer.
5. The method of claim 4 , wherein the polymer comprises an isotactic copolymer of butene-1.
6. The method of claim 1 , wherein at least one of the substrates comprises at least one of paperboard and corrugated paperboard.
7. The method of claim 1 , wherein the composition exhibits at least about 70% fiber tear after about 10 minutes and no greater than about 10% fiber tear after about 24 hours when tested according to at least one of the Median Coupon Test and the Modified Median Coupon Test.
8. The method of claim 1 , wherein the composition exhibits a melt viscosity of from about 40 cps to about 2,000 cps at 350° F. (177° C.).
9. A method of temporarily adhering a first container to a second container, the method comprising:
a) applying a hot melt composition comprising a metallocene catalyzed polypropylene homopolymer to a first surface of the first container to form a first bonding surface; and
b) contacting the first bonding surface of the first container with the second container to temporarily adhesively bond the first container to the second container through the composition.
10. The method of claim 9 , further comprising allowing the composition to lose adhesion, thereby allowing the second container to separate from the first container with no greater than about 20% fiber tear after 24 hours when tested according to at least one of the Median Coupon Test and the Modified Median Coupon Test.
11. The method of claim 9 , wherein the first and the second containers are paperboard containers.
12. The method of claim 9 , wherein the composition exhibits a Loop Tack of less than about 5 ounces per inch.
13. The method of claim 9 , wherein the composition further comprises tackifying resin, wax, antioxidant, or a combination thereof.
14. The method of claim 9 , wherein the metallocene catalyzed polypropylene homopolymer has a heat of fusion of no greater than about 40 J/g.
15. The method of claim 9 , wherein at least one of the first and the second containers is filled with consumer goods, the consumer goods having been placed into the container on an automated packaging line, and the temporarily adhesively bonded first and the second containers are separable from each other with no greater than about 20% fiber tear prior to a sale to a customer at a final point of sale.