HK1243115B - Hot melt adhesive compositions that include semi-crystalline propylene polymer and wax and articles including the same - Google Patents

Description

Hot melt adhesive composition comprising a semicrystalline propylene polymer and a wax and articles comprising the same

background

The present invention relates to the preparation of hot melt adhesive compositions comprising a semicrystalline propylene polymer and a wax.

Hot melt adhesive compositions typically include polymers and tackifiers and, in some cases, waxes or oils. Hot melt adhesives used for packaging should exhibit good bonding formation, heat resistance and thermal stability, and rapid setting time to be commercially useful. It is difficult to formulate propylene polymer-based hot melt adhesive compositions that exhibit the performance properties that packaging adhesives must satisfy commercially. Tackifiers, for example, can cause discoloration and charring of the hot melt adhesive. Waxes have a deleterious effect on the bonding formation of polypropylene hot melt adhesive compositions. Waxes with high crystallinity are particularly so. Oils are known to reduce the setting speed of hot melt adhesive compositions. Oils can also ooze out of the hot melt adhesive composition and cause undesirable staining of the substrate to which they are bonded.

It would be desirable to have a propylene polymer based hot melt adhesive composition that exhibits good adhesion at both low and high temperatures, thermal stability, fast set times, and little to no oil staining and oil migration.

Overview

In one aspect, the present invention provides a hot melt adhesive composition comprising at least 55 wt% of an unmodified semi-crystalline propylene polymer comprising at least 50 wt% propylene, at least 15 wt% of a first non-functionalized wax, and a second wax different from the first wax. In some embodiments, the hot melt adhesive composition comprises greater than 20 wt% of the wax.

In another aspect, the present invention provides a hot melt adhesive composition comprising at least 55 wt% of a semi-crystalline propylene polymer comprising at least 50 wt% propylene and greater than 20 wt% of a wax, the wax comprising 0 wt% to no greater than 10 wt% of a functionalized wax, based on the weight of the hot melt adhesive composition, wherein the composition exhibits a set time of no greater than 2 seconds. In one embodiment, the wax comprises a first wax and a second wax different from the first wax.

In some embodiments, the hot melt adhesive composition includes no greater than 10 weight percent of a tackifier.

In one embodiment, the second wax comprises a functionalized wax.

In another embodiment, the semi-crystalline propylene polymer is a metallocene-catalyzed propylene polymer. In some embodiments, the semi-crystalline propylene polymer has a heat of fusion of 15 J/g to no more than 50 J/g. In one embodiment, the semi-crystalline propylene polymer has a heat of fusion of 15 J/g to no more than 45 J/g.

In another embodiment, the first non-functionalized wax has a melting point greater than 80°C. In some embodiments, the first non-functionalized wax has a melting point greater than 100°C. In other embodiments, the first non-functionalized wax has a melting point greater than 115°C. In one embodiment, the second wax has a melting point greater than 115°C. In some embodiments, the first non-functionalized wax has a melting point greater than 115°C and the composition exhibits a set time of no greater than 2 seconds. In some embodiments, the first non-functionalized wax has a melting point greater than 115°C and the second wax has a melting point greater than 115°C.

In some embodiments, the composition exhibits a setting time of no greater than 5 seconds. In other embodiments, the composition exhibits a setting time of no greater than 2 seconds.

In one embodiment, the composition exhibits a heat stress resistance greater than 71°C. In other embodiments, the composition exhibits a heat stress resistance greater than 76°C. In some embodiments, the composition exhibits a heat stress resistance greater than 71°C and a set time of no greater than 2 seconds. In one embodiment, the composition exhibits a heat stress resistance greater than 71°C and a set time of no greater than 2 seconds, and the first non-functionalized wax comprises at least one of a polyethylene wax and a Fischer-Tropsch wax, and the second wax comprises a non-functionalized polypropylene wax, a maleated polyethylene wax, a maleated polypropylene wax, or a combination thereof.

In another embodiment, the composition exhibits greater than 25% fiber tear at -18°C and greater than 25% fiber tear at 60°C. In other embodiments, the composition exhibits greater than 25% fiber tear at 4°C and greater than 25% fiber tear at 60°C. In still other embodiments, the composition exhibits greater than 25% fiber tear at 4°C and greater than 25% fiber tear at 71°C.

In one embodiment, the hot melt adhesive composition further comprises oil, polybutene or a combination thereof. In other embodiments, the hot melt adhesive composition further comprises a tackifier. In one embodiment, the hot melt adhesive composition comprises no more than 7% by weight of a tackifier.

In some embodiments, the composition exhibits a viscosity of no greater than 2000 centipoise at 177° C. In other embodiments, the composition exhibits a viscosity of no greater than 1200 centipoise at 177° C.

In one embodiment, the first non-functionalized wax comprises a polyethylene wax, and the second wax comprises a non-functionalized polypropylene wax, a maleated polyethylene wax, a maleated polypropylene wax, or a combination thereof. In some embodiments, the first non-functionalized wax exhibits a melting point greater than 115° C. and comprises at least one of a polyethylene wax and a Fischer-Tropsch wax, and the second wax comprises a maleated polyethylene wax, a maleated polypropylene wax, or a combination thereof. In other embodiments, the first non-functionalized wax comprises a polyethylene wax, and the second wax comprises a maleated polyethylene wax, a maleated polypropylene wax, or a combination thereof.

In some embodiments, the hot melt adhesive composition comprises 55% to about 84% by weight of a semi-crystalline propylene polymer, about 20% to about 35% by weight of a first non-functionalized wax, and about 1% to about 10% by weight of a second wax. In one embodiment, the composition exhibits a setting time of no more than 2 seconds. In other embodiments, the composition exhibits a setting time of no more than 1 second.

In other embodiments, the hot melt adhesive composition includes 60% to about 80% by weight polypropylene polymer.

In one embodiment, the semi-crystalline propylene polymer comprises a propylene-alpha olefin copolymer. In another embodiment, the semi-crystalline propylene polymer comprises a propylene-hexene copolymer, a propylene-octene copolymer, a propylene-butene copolymer, a propylene-ethylene copolymer, or a combination thereof. In some embodiments, the semi-crystalline propylene polymer exhibits a viscosity of no greater than 2,000 cP at 190°C. In other embodiments, the semi-crystalline propylene polymer exhibits a viscosity of no greater than 1200 cP at 190°C. In another embodiment, the hot melt adhesive composition exhibits a heat stress resistance of greater than 71°C, a fiber tear of greater than 25% at -18°C, and a fiber tear of greater than 25% at 60°C.

In another embodiment, the composition exhibits a viscosity of no greater than 1500 centipoise at 149°C.

In another aspect, the present invention provides a package comprising the hot melt adhesive composition described herein, a first substrate comprising fibers, and a second substrate comprising fibers, the second substrate being bonded to the first substrate via the adhesive composition. In one embodiment, the adhesive exhibits fiber tearing adhesion to at least one of the first substrate and the second substrate at -18°C and at 60°C.

In another aspect, the present invention proposes a hot melt adhesive composition, it comprises at least 40 % by weight of an unmodified semi-crystalline propylene polymer comprising at least 50 % by weight propylene, at least 15 % by weight of a non-functionalized wax and the ethylene-ethylenically unsaturated ester copolymer of not more than 8 % by weight, the non-functionalized wax comprising the first non-functionalized wax and the second non-functionalized wax being different from the first non-functionalized wax. In one embodiment, the adhesive composition further comprises an elastomeric block copolymer comprising styrene. In some embodiments, the elastomeric block copolymer is selected from styrene-ethylene/butylene-styrene block copolymer, styrene-ethylene/propylene-styrene block copolymer and combinations thereof.

In other aspects, the present invention provides a hot melt adhesive composition comprising at least 40 wt% of an unmodified semi-crystalline propylene polymer comprising at least 50 wt% propylene, at least 15 wt% of a non-functionalized wax, 0 wt% to no more than 10 wt% of a functionalized wax, and 1 wt% to 10 wt% of an elastomeric block copolymer comprising styrene.

In some embodiments, the adhesive composition comprises at least 45 wt% unmodified semi-crystalline propylene polymer. In other embodiments, the adhesive composition comprises at least 50 wt% unmodified semi-crystalline propylene polymer. In other embodiments, the adhesive composition comprises at least 55 wt% unmodified semi-crystalline propylene polymer.

In other embodiments, the adhesive composition includes 45 wt% to about 70 wt% unmodified semi-crystalline propylene polymer, about 20 wt% to about 35 wt% non-functionalized wax, and about 1 wt% to about 10 wt% functionalized wax.

In other embodiments, the unmodified semi-crystalline propylene polymer exhibits a heat of fusion from 15 J/g to no greater than 50 J/g.

In one embodiment, the first non-functionalized wax comprises polyethylene wax, Fischer-Tropsch wax, or a combination thereof. In some embodiments, the first non-functionalized wax has a melting point greater than 100°C. In other embodiments, the second non-functionalized wax has a melting point greater than 115°C.

In one embodiment, the adhesive composition further comprises a functionalized wax. In some embodiments, the first non-functionalized wax comprises polyethylene wax, Fischer-Tropsch wax, or a combination thereof, and the functionalized wax comprises maleated polyethylene wax, maleated polypropylene wax, or a combination thereof.

In some embodiments, the first non-functionalized wax has a melting point greater than 100° C. In other embodiments, the first non-functionalized wax has a melting point greater than 100° C. and the second non-functionalized wax has a melting point greater than 110° C.

In some embodiments, the adhesive composition includes greater than 20 weight percent wax.

In another embodiment, the adhesive composition exhibits a setting time of no more than 2 seconds. In other embodiments, the adhesive composition exhibits a setting time of no more than 1.5 seconds. In other embodiments, the adhesive composition exhibits a setting time of no more than 1 second.

In some embodiments, the adhesive composition exhibits a thermal stress resistance greater than 60°C, greater than 50% fiber tear at 4°C, and greater than 50% fiber tear at 60°C, and a setting time of no more than 2 seconds. In other embodiments, the adhesive composition exhibits a thermal stress resistance greater than 60°C, greater than 50% fiber tear at 4°C, greater than 50% fiber tear at 60°C, and a setting time of no more than 1.5 seconds. In another embodiment, the adhesive composition exhibits a thermal stress resistance greater than 71°C, greater than 50% fiber tear at 4°C, greater than 50% fiber tear at 71°C, and a setting time of no more than 1.5 seconds. In another embodiment, the adhesive composition exhibits a thermal stress resistance greater than 71°C, greater than 50% fiber tear at -18°C, greater than 50% fiber tear at 71°C, and a setting time of no more than 1.5 seconds.

In other embodiments, the adhesive composition further comprises oil, polybutene, or a combination thereof.

In another embodiment, the adhesive composition exhibits a viscosity of no greater than 2000 centipoise at 177° C. In other embodiments, the adhesive composition exhibits a viscosity of no greater than 1500 centipoise at 149° C.

In other embodiments, the adhesive composition includes 50 wt% to about 65 wt% of the unmodified semi-crystalline polypropylene polymer.

In other embodiments, the unmodified semi-crystalline propylene polymer exhibits a viscosity of no greater than 1200 cP at 190°C.

In another embodiment, the unmodified semi-crystalline propylene polymer comprises an unmodified, metallocene-catalyzed semi-crystalline propylene polymer, an unmodified, non-metallocene heteroaryl-catalyzed semi-crystalline propylene polymer, or a combination thereof.

In another embodiment, the unmodified semi-crystalline propylene polymer comprises an unmodified, metallocene-catalyzed semi-crystalline propylene copolymer, an unmodified, non-metallocene heteroaryl-catalyzed semi-crystalline propylene copolymer, or a combination thereof.

In other embodiments, the adhesive composition further comprises 15 wt % to 30 wt % of a tackifier.

In another aspect, the present invention provides a package comprising any of the hot melt adhesive compositions disclosed above, a first substrate comprising fibers, and a second substrate comprising fibers, the second substrate being bonded to the first substrate by the adhesive composition.

The present invention provides a semi-crystalline propylene polymer based hot melt adhesive composition that exhibits fast setting time, thermal stability and good adhesion at both low and high temperatures.

Other features and advantages will be apparent from the following description of the preferred embodiments, and from the claims.

Glossary

With respect to the present invention, these terms have the following meanings:

As used herein, the term "wax" refers to a polymer or oligomer having a heat of fusion greater than 60 Joules/gram and a viscosity no greater than 750 centipoise (cP) at 190°C.

The term "semi-crystalline polymer" refers to a polymer having a heat of fusion greater than 10 J/g and no greater than 60 J/g and a viscosity at 190°C of at least 750 cP.

The term "unmodified polymer" refers to a polymer that has not been modified in the presence of a free radical initiator.

The term "non-functionalized wax" refers to a wax that does not contain polar functional groups.

The term "functionalized wax" refers to a wax having at least one polar functional group.

Details

The hot melt adhesive composition comprises at least 40% by weight of a semi-crystalline propylene polymer comprising at least 50% by weight propylene and a wax. The hot melt adhesive composition exhibits a fast set time, preferably no greater than 5 seconds, no greater than 3 seconds, no greater than 2 seconds, no greater than 1.5 seconds, or even no greater than 1 second. The hot melt adhesive composition also exhibits fiber-tear adhesion to fibrous packaging materials at both low and high temperatures. The hot melt adhesive composition preferably exhibits fiber tear at temperatures of greater than 25%, greater than 30%, greater than 40%, greater than 45%, greater than 50%, or even greater than 70% at 4°C, -18°C, or even -29°C, and greater than 25%, greater than 30%, greater than 40%, greater than 45%, greater than 50%, or even greater than 70% at temperatures of 60°C or even 71°C.

The hot melt adhesive composition also exhibits good thermal stress resistance, preferably a thermal stress resistance of at least 54°C, at least 60°C, at least 66°C, at least 71°C or even at least 76°C.

The hot melt adhesive composition preferably exhibits a viscosity of no greater than 5000 cP, no greater than about 3000 cP, no greater than about 2000 cP, no greater than about 1500 cP, no greater than about 1200 cP, or even no greater than about 1000 cP at 177° C. and a viscosity of no greater than about 3000 cP, no greater than about 2000 cP, or even no greater than about 1000 cP at 190° C. The hot melt adhesive composition can be formulated to exhibit a viscosity of no greater than 2000 cP, no greater than about 1500 cP, no greater than about 1300 cP, or even no greater than about 1200 cP at 149° C. or even at 135° C.

The hot melt adhesive composition also exhibits good thermal stability. Two measures of thermal stability are viscosity change over time and the presence of charring. After conditioning at 177°C for 200 hours, the hot melt adhesive composition preferably exhibits a viscosity change of no more than 20%, or even no more than 10%, relative to its initial viscosity at 177°C, and exhibits minimal or even no charring and skinning, i.e., the formation of a skin on the surface of the composition.

The hot melt adhesive composition also preferably exhibits an initial Gardner color of no greater than 3, no greater than 2, or even no greater than 1.

Semi-crystalline propylene polymer

The propylene polymer is semi-crystalline and exhibits a heat of fusion of greater than 10 Joules/gram (J/g) to no greater than 60 J/g, about 15 J/g to about 50 J/g, or even about 15 J/g to about 45 J/g. The propylene polymer exhibits a viscosity at 190° C. of at least 750 cP, no greater than 5,000 cP, no greater than 4,000 cP, no greater than 3,000 cP, no greater than 2,000 cP, or even no greater than 1,000 cP.

The propylene polymer preferably exhibits a glass transition temperature (Tg) of no greater than -10°C, no greater than -20°C, or even no greater than -30°C.

Useful propylene polymers include, for example, polypropylene homopolymers (i.e., 100 mol % propylene), propylene copolymers (i.e., copolymers, terpolymers, and higher order polymers), mixtures of at least two different propylene polymers, including, for example, blends comprising a polypropylene homopolymer and a propylene copolymer, blends comprising different polypropylene homopolymers, blends comprising different propylene copolymers, and various combinations thereof. Useful propylene polymers also include, for example, modified, unmodified, grafted, and ungrafted propylene polymers, unimodal propylene polymers, multimodal propylene polymers, and combinations thereof. The term "multimodal" refers to a polymer having a multimodal molecular weight distribution (weight average molecular weight (Mw)/number average molecular weight (Mn)) as determined by size exclusion chromatography (SEC). A multimodal molecular weight distribution exists when the SEC trace has more than one peak or inflection point (i.e., two or more inflection points). An inflection point is a point at which the sign of the second derivative changes (e.g., from negative to positive, or vice versa). The term "unimodal" refers to a polymer having a unimodal molecular weight distribution (Mw/Mn) as determined by SEC. When an SEC trace has only one peak, a unimodal molecular weight distribution exists.

Useful propylene copolymers are derived from propylene and an α-olefin comonomer (e.g., α-olefin monomers having at least 2 carbon atoms, at least 4 carbon atoms, 4 to 8 carbon atoms, and combinations of such monomers). Examples of suitable types of α-olefin comonomers include mono-α-olefins (i.e., one unsaturated double bond) and higher α-olefins (e.g., dienes (e.g., 1,9-decadiene)). Useful α-olefin monomers include, for example, ethylene, butene, pentene, hexene, heptene, octene, nonene, decene, dodecene, 4-methyl-pentene-1, 3-methylpentene-1, 3,5,5-trimethyl-hexene-1, 5-ethyl-1-nonene, and combinations thereof. Specific examples of suitable propylene-α-olefin copolymers include propylene-ethylene, propylene-butene, propylene-hexene, propylene-octene, and combinations thereof.

The propylene copolymer preferably comprises at least 1 wt%, at least 2 wt%, at least about 5 wt%, at least about 10 wt%, no more than 50 wt%, no more than about 40 wt%, no more than 30 wt%, no more than 20 wt%, no more than 17 wt%, no more than 15 wt%, or even no more than 10 wt% α-olefin comonomer and at least 50 wt%, at least about 60 wt%, no more than 99 wt%, no more than 98 wt%, no more than 95 wt%, no more than 90 wt%, from about 50 wt% to about 99 wt%, from about 60 wt% to about 99 wt%, or even from about 70 wt% to about 99 wt% propylene.

Useful propylene polymers include propylene polymers made using various catalysts, including, for example, single-site catalysts (e.g., metallocene catalysts (e.g., metallocene-catalyzed propylene polymers)), multiple single-site catalysts, non-metallocene heteroaryl catalysts, and combinations thereof. Other suitable polymers include polymers made by grafting an amorphous propylene polymer onto a semi-crystalline polymer, examples of which and methods of making the same are disclosed, for example, in U.S. 7,541,402 (Abhari et al.) and incorporated herein. The propylene polymer may include isotactic polypropylene blocks and atactic polypropylene blocks.

Suitable propylene polymers are available under various trade names, including, for example, VISTAMAXX 8880 propylene-ethylene copolymer, VISTAMAXX 8816 propylene-hexene copolymer, and LINXAR propylene-hexene copolymers, including LINXAR 127, from ExxonMobil Chemical Company (Houston, Texas), and LICOCENE propylene-ethylene copolymers, including, for example, LICOCENE PP 1502 TP, PP 1602 TP, and PP 2602 TP, from Clariant Int'l Ltd. (Muttenz, Switzerland).

The hot melt adhesive composition includes at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, no more than about 84 wt%, no more than about 80 wt%, no more than about 75 wt%, about 70 wt%, no more than about 65 wt%, no more than about 60 wt%, about 40 wt% to about 84 wt%, about 45 wt% to about 80 wt%, or even about 45 wt% to about 60 wt% propylene polymer.

wax

The hot melt adhesive composition includes at least two different waxes (e.g., at least two different non-functionalized waxes, at least two different functionalized waxes, functionalized waxes and non-functionalized waxes, and combinations thereof). The hot melt adhesive composition includes at least 15 wt%, greater than 15 wt%, greater than 20 wt%, between 20 wt% and 35 wt%, at least 15 wt% to approximately 35 wt%, greater than 15 wt% to approximately 35 wt%, or even between approximately 15 wt% and approximately 30 wt% wax.

Non-functionalized wax

Useful non-functionalized waxes have a melting point of at least 50° C., at least 60° C., at least 80° C., at least 100° C., or even at least 115° C. and a heat of fusion of greater than 60 J/g or even greater than 70 J/g. Examples of suitable non-functionalized waxes include polyolefin waxes (e.g., polypropylene waxes and polyethylene waxes), Fischer-Tropsch waxes, paraffin waxes, microcrystalline waxes, metallocene waxes, and combinations thereof (e.g., a combination of two non-functionalized waxes each having a melting point of at least 115° C.). The hot melt adhesive composition preferably includes at least 15% by weight, greater than 15% by weight, greater than 20% by weight, at least 15% to about 35% by weight, greater than 15% to about 35% by weight, or even about 15% to about 30% by weight of non-functionalized wax.

Useful polyethylene waxes are available under various trade names, including, for example, the EPOLENE series from Westlake Chemical Corporation (Houston, Texas), including, for example, EPOLENE N-21 and N-14 polyethylene waxes, the BARECO series from Baker Hughes Inc. (Sugar Land, Texas), including, for example, BARECO C4040 polyethylene wax, the AC series from Honeywell Int'l Inc. (Morristown, New Jersey), including, for example, A-C 8 and A-C 9 polyethylene waxes, the POLYWAX series from Baker Hughes (Houston, Texas), including POLYWAX 3000 polyethylene wax, and CWP 400 polyethylene wax from SSI CHUSEI, Inc. (Pasedena, Texas). The hot melt adhesive composition may include 0 wt % to about 35 wt %, at least 1 wt %, at least 7 wt %, at least 10 wt %, about 1 wt % to about 30 wt %, about 1 wt % to about 25 wt %, about 5 wt % to about 20 wt %, or even about 5 wt % to about 15 wt % polyethylene wax.

Useful polypropylene waxes are available under various trade names, including, for example, EPOLENE N-15 from Westlake Chemical, HONEYWELL AC1089 from Honeywell Int'l Inc., and LICOCENE 6102 from Clariant Int'l Ltd. (Muttenz, Switzerland). The hot melt adhesive composition can include 0 wt % to about 35 wt %, about 1 wt % to about 25 wt %, or even about 1 wt % to about 20 wt % polypropylene wax.

Useful Fischer-Tropsch waxes are available under various trade names, including, for example, the BARECO series from Baker Hughes Inc. (SugarLand, Texas), including, for example, BARECO PX-100 and PX-105 Fischer-Tropsch waxes, the SHELLWAX series from Shell Malaysia Ltd. (Kuala Lumpur, Malaysia), including, for example, SHELLWAX SX100 and SX105 Fischer-Tropsch waxes, the VESTOWAX series from Evonik Industries AG (Germany), including, for example, VESTOWAX 2050 Fischer-Tropsch wax, and the SASOLWAX series from Sasol Wax North America Corporation (Hayward, California), including, for example, SASOLWAX H105, C80, H1, and H4 Fischer-Tropsch waxes. The hot melt adhesive composition may include 0 wt % to approximately 35 wt %, at least 1 wt %, at least approximately 5 wt %, approximately 1 wt % to approximately 30 wt %, approximately 1 wt % to approximately 25 wt %, approximately 5 wt % to approximately 10 wt %, or even approximately 4 wt % to approximately 8 wt % Fischer-Tropsch wax.

Useful paraffin waxes are available under various trade names, including, for example, PARVAN 1580 and 1520 paraffin waxes from ExxonMobil Chemical Company (Houston, Texas) and CALUMET FR-6513 from Calumet Specialty Products Partners, LP (Indianapolis, Indiana). The hot melt adhesive composition can include 0 wt % to about 35 wt %, about 1 wt % to about 25 wt %, about 1 wt % to about 20 wt %, or even about 0 wt % to about 15 wt % paraffin wax.

functionalized wax

Useful functionalized waxes have a melting point of at least 50° C., at least 60° C., at least 80° C., at least 100° C., or even at least 115° C., and a heat of fusion greater than 60 J/g or even greater than 70 J/g. Examples of suitable functionalized waxes include functionalized polypropylene waxes (e.g., maleated polypropylene waxes and oxidized polypropylene waxes), functionalized polyethylene waxes (e.g., maleated polyethylene waxes and oxidized polyethylene waxes), polar waxes, functionalized stearamide waxes (e.g., hydroxystearamide, N-(2-hydroxyethyl)-12-hydroxystearamide, N,N′-ethylenebis-12-hydroxystearamide and 12-hydroxystearic acid, N,N′ethylene-bis-stearamide), and combinations thereof. Useful commercially available functionalized waxes include, for example, A-C 597P, A-C 596P, and A-C 1325 maleated polypropylene waxes and A-C 573 maleated polyethylene wax, all available from Honeywell International Inc. (Morristown, New Jersey), and Westlake E 43 maleated polypropylene wax available from Westlake Chemical Corporation (Houston, Texas).

The functionalized wax can be present in the hot melt adhesive composition in an amount of from about 0% to no more than 10% by weight, from about 1% to no more than 10% by weight, from about 0.2% to about 5% by weight, from about 1% to about 4% by weight, from about 2% to about 3.5% by weight, no more than 2% by weight, or even no more than 1% by weight. Optionally, the hot melt adhesive composition does not contain a functionalized wax.

Oil

The hot melt adhesive composition optionally includes oil. Available types of oil include, for example, naphthenic petroleum-based oils, paraffinic oils (e.g., cycloparaffin oils), mineral oils, animal oils, vegetable oils, synthetic oils, derivatives of oils, glycerides of fatty acids, and combinations thereof.

Useful commercial oils include KAYDOL OIL from Sonneborn (Tarrytown, New York), KRYSTOL 550 mineral oil from Petrochem Carless Limited (Surrey, England), and CALSOL 550 naphthenic oil from Calumet Specialty Products Partners, LP (Indianapolis, Indiana).

The hot melt adhesive composition optionally includes 0 wt % to no greater than about 20 wt %, no greater than about 15 wt %, no greater than about 12 wt %, about 0.5 wt % to about 10 wt %, about 1 wt % to about 10 wt %, or even about 2 wt % to about 5 wt % oil.

polybutene

The hot melt adhesive composition optionally includes a polybutene with a weight average molecular weight of not more than about 2000 grams per mole. Available polybutene is available under various trade names, including, for example, TPC595 from TPC Group (Houston, Texas), the trade name of the INDOPOL series from Ineos Europe, Limited (Belgium), and the trade name of the PARAPOL series from ExxonMobil Chemical Company (Houston, Texas).

The hot melt adhesive composition optionally includes 0 wt % to no greater than about 20 wt %, no greater than about 15 wt %, no greater than about 12 wt %, about 0.5 wt % to about 10 wt %, about 1 wt % to about 10 wt %, or even about 2 wt % to about 5 wt % polybutylene.

Tackifier

The hot melt adhesive composition optionally includes a tackifier. Useful tackifiers exhibit a Tg of no greater than 90°C, no greater than 80°C, no greater than 70°C, no greater than 60°C, or even no greater than 50°C, and a Ring and Ball softening point of less than about 160°C. Suitable classes of tackifiers include, for example, aromatic, aliphatic, and cycloaliphatic hydrocarbon resins, mixed aromatic and aliphatic modified hydrocarbon resins, aromatic-modified aliphatic hydrocarbon resins, and hydrogenated forms thereof; terpenes, modified terpenes, and hydrogenated forms thereof; natural rosins, modified rosins, rosin esters, and hydrogenated forms thereof; low molecular weight polylactic acid; and combinations thereof. Examples of useful natural and modified rosins include gum rosin, wood rosin, tall oil rosin, distilled rosin, hydrogenated rosin, dimerized rosin, and polymerized rosin. Examples of useful rosin esters include, for example, glycerol esters of pale wood rosin, glycerol esters of hydrogenated rosin, glycerol esters of polymerized rosin, pentaerythritol esters of natural and modified rosins, including pentaerythritol esters of pale wood rosin, pentaerythritol esters of hydrogenated rosin, pentaerythritol esters of tall oil rosin, phenol-modified pentaerythritol esters of rosin, and combinations thereof. Examples of useful polyterpene resins include polyterpene resins having a softening point of about 10° C. to about 160° C. as determined by ASTM method E28-58T, copolymers and terpolymers of hydrogenated polyterpene resins and natural terpenes (e.g., styrene-terpene, α-methylstyrene-terpene, and vinyltoluene-terpene), and combinations thereof. Examples of useful aliphatic and alicyclic petroleum hydrocarbon resins include aliphatic and alicyclic petroleum hydrocarbon resins having a ring and ball softening point of about 10° C. to 160° C., hydrogenated derivatives thereof, and combinations thereof. Suitable aliphatic and cycloaliphatic petroleum hydrocarbon resins include, for example, branched, unbranched, and cyclic C5 resins, C9 resins, and C10 resins.

Useful tackifiers are available under various trade names, including, for example, the ESCOREZ series from ExxonMobil Chemical Company (Houston, Texas), including, for example, ESCOREZ 1310LC, ESCOREZ 5400, ESCOREZ 5637, ESCOREZ 5415, ESCOREZ 5600, ESCOREZ 5615, and ESCOREZ 5690, the EASTOTAC series from Eastman Chemical Company (Kingsport, Tennessee), including, for example, Eastotac H-100R, EASTOTAC H-100L, and EASTOTAC H130W, the WINGTACK series from Cray Valley HSC (Exton, Pennsylvania), including, for example, WINGTACK 86, WINGTACK EXTRA, and WINGTACK 95, the WINGTACK series from Eastman Chemical Company (Kingsport, Tennessee), including, for example, Eastotac H-100R, EASTOTAC H-100L, and EASTOTAC H130W, the WINGTACK series from Cray Valley HSC (Exton, Pennsylvania), including, for example, WINGTACK 86, WINGTACK EXTRA, and WINGTACK 95, the WINGTACK series from Eastman Chemical Company (Kingsport, Tennessee), including, for example, WINGTACK 86, WINGTACK EXTRA, and WINGTACK 95. Company (Kingsport, Tennessee), including, for example, PICCOTAC 8095 and 1115, the ARKON series of trade names from Arkawa Europe GmbH (Germany), including, for example, ARKON P-125, the REGALITE and REGALREZ series of trade names from Eastman Chemical Company, including, for example, REGALITE R1125 and REGALREZ 1126, and the RESINALL series of trade names from Resinall Corp (Severn, North Carolina), including RESINALL R1030.

Useful tackifiers that are liquid at room temperature (ie, 20°F to 22°F) include, for example, REGALREZ 1018 hydrocarbon resin from Eastman Chemical Company, PICCOLASTIC A5 hydrocarbon resin from Eastman Chemical Company, and WINGTACK 10 from Cray Valley (Exton, Pennsylvania).

The hot melt adhesive composition optionally includes at least about 1 wt %, at least 5 wt %, at least about 10 wt %, at least about 15 wt %, at least about 20 wt %, no more than about 40 wt %, no more than about 35 wt %, no more than about 30 wt %, no more than about 25 wt %, from about 15 wt % to about 30 wt %, or even from about 20 wt % to about 25 wt % tackifier.

For some hot melt adhesive compositions comprising at least 55 wt% semi-crystalline polypropylene polymer, useful amounts of the optional tackifier include from about 0 wt% to not greater than about 30 wt%, 1 wt% to not greater than about 30 wt%, from about 1 wt% to about 20 wt%, from about 1 wt% to about 15 wt%, from about 1 wt% to about 10 wt%, not greater than 10 wt%, not greater than about 7 wt%, or even not greater than about 0.5 wt%.

additive

The hot melt adhesive composition optionally includes various additional components including, for example, antioxidants, stabilizers, additional polymers, adhesion promoters, UV stabilizers, rheology modifiers, corrosion inhibitors, colorants (e.g., pigments and dyes), fillers, flame retardants, nucleating agents, and combinations thereof.

Useful antioxidants include, for example, pentaerythritol tetrakis[3,(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-methylenebis(4-methyl-6-tert-butylphenol)phosphites, including, for example, tris-(p-nonylphenyl)phosphite (TNPP) and bis(2,4-di-tert-butylphenyl) 4,4'-diphenylene-diphosphonite, di-stearyl-3,3'-thiodipropionate (DSTDP), and combinations thereof. Useful antioxidants are available under various trade names, including, for example, the IRGANOX series of trade names, including, for example, IRGANOX 1010, IRGANOX 565, and IRGANOX 1076 hindered phenolic antioxidants, and IRGAFOS 168 phosphite antioxidant, all available from BASF Corporation (Florham Park, New Jersey), and ETHYL 702 4,4'-methylenebis(2,6-di-tert-butylphenol), available from Albemarle Corporation (Baton Rouge, Louisiana). When present, the adhesive composition preferably includes from about 0.1% to about 2% by weight of the antioxidant.

Useful additional polymers include, for example, homopolymers, copolymers, and terpolymers, thermoplastic polymers including, for example, other polyolefins (e.g., high viscosity polyolefins (e.g., high viscosity propylene ethylene polymers), Ziegler-Natta catalyzed amorphous polyalphaolefins (e.g., amorphous propylene ethylene polymers) and combinations thereof), elastomers including, for example, elastomeric block copolymers (e.g., elastomeric block copolymers including styrene (e.g., styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene/butylene-styrene, styrene-ethylene/propylene-styrene, and combinations thereof), metallocene-based elastomeric block copolymers and combinations thereof), and functionalized versions thereof and combinations thereof.

High viscosity polymers exhibit a viscosity greater than 100,000 at 121°C. Additional high viscosity polyolefin polymers that can be used include, for example, high viscosity amorphous polyalphaolefins, high viscosity crystalline polyolefins, high viscosity semi-crystalline polyolefins, and combinations thereof. Suitable high viscosity polyolefins are available under the trade designation L-MODU series from Idemitsu Kosan Co., Ltd. (Japan), including, for example, L-MOD US400, S600, and S901 propylene homopolymers, and VISTAMAXX propylene-ethylene copolymers from ExxonMobil Chemical Company (Houston, Texas), including, for example, VISTAMAXX 6202, 3980, and 2330.

Ziegler-Natta catalyzed amorphous polyalphaolefin polymers are available commercially under various trade names, including, for example, the REXTAC series available from Rextac LLC (Odessa, Texas) and the EASTOFLEX and AERAFIN series from Eastman Chemical Company (Kingsport Tennessee).

The hot melt adhesive composition optionally includes no greater than about 10 weight percent, from about 1 weight percent to no greater than about 7 weight percent, or even no greater than about 5 weight percent of a polyolefin polymer other than a semicrystalline propylene polymer.

Useful elastomeric block copolymers are available under various trade names, including, for example, KRATON G 1657 styrene-ethylene/butylene-styrene block copolymer and G1652 styrene-ethylene/propylene-styrene block copolymer from Kraton Polymers U.S. LLC (Houston, Texas), and VECTOR 4411 styrene-isoprene-styrene block copolymer from TSRC Dexco Polymers LP (Taipei City, Taiwan R.O.C.). The hot melt adhesive composition optionally includes from about 1% to about 10%, or even from about 4% to about 10%, by weight of a block copolymer comprising styrene.

The hot melt adhesive composition is preferably free of ethylene-ethylenically unsaturated ester copolymers, such as ethylene vinyl acetate, ethylene acrylate, ethylene methacrylate, and ethylene butyl acrylate. When an ethylene-ethylenically unsaturated ester copolymer is present in the hot melt adhesive composition, it is preferably present in an amount of less than 8 wt%, no more than 5 wt%, no more than 3 wt%, or even no more than 1 wt%.

use

The hot melt adhesive composition can be applied to or incorporated into a variety of articles, including, for example, fibers, substrates made from fibers (e.g., virgin fiber, recycled fiber, synthetic polymer fibers (e.g., nylon, rayon, polyester, acrylic, polypropylene, polyethylene, polyvinyl chloride, polyurethane), cellulosic fibers (e.g., natural cellulosic fibers such as wood pulp), natural fibers (e.g., cotton, silk, and wool), and glass fibers, and combinations thereof), release liners, porous substrates, cellulosic substrates, sheets (e.g., paper and fiber sheets), paper products, woven and nonwoven webs (e.g., webs made from fibers (e.g., yarn, thread, filament, microfiber, blown fiber, and spun fiber), perforated films, and combinations thereof), tape backings, and combinations thereof.

The hot melt adhesive composition can be used to bond a variety of substrates including, for example, cardboard, coated cardboard, paperboard, fiberboard, virgin and recycled kraft paper, high and low density kraft paper, particleboard, treated and coated kraft paper and particleboard, and corrugated forms thereof, clay coated chipboard carton stock, composites, leather, fibers and substrates made from fibers (e.g., virgin fibers, recycled fibers, synthetic polymer fibers, cellulosic fibers, and combinations thereof), release liners, porous substrates (e.g., woven webs, nonwoven webs, and perforated films), cellulosic substrates, sheet materials (e.g., paper and fiber sheets), paper products, tape backings, and combinations thereof.

The hot melt adhesive composition can be used to bond a first substrate to a second substrate in a variety of applications and configurations, including, for example, packages, bags, boxes, cartons, cases, trays, multi-layer bags, articles including accessories (e.g., straws attached to beverage cartons), ream wrap, cigarettes (e.g., plug wrap), filters (e.g., pleated filters and filter frames), bookbindings, paper products, including, for example, tissues (e.g., multi-purpose towels), toilet paper, facial tissue, wipes, tissues, towels (e.g., paper towels), and combinations thereof.

The hot melt adhesive composition can be applied to a substrate in any useful form, including, for example, as a coating (e.g., continuous coating and discontinuous coating (e.g., random, pattern or array)), as beads, as a film (e.g., continuous film and discontinuous film), and combinations thereof, using any suitable application method, including, for example, slot coating, spraying (e.g., spiral spraying, random spraying and random fiberization (e.g., melt blowing)), foaming, extrusion (e.g., bead application, strand extrusion, single screw extrusion and twin screw extrusion), wheel application, non-contact coating, contact coating, gravure printing, engraved roller, roller coating, transfer coating, screen printing, flexographic printing, "on demand" application, and combinations thereof.

In an on-demand hot melt application system (which is also referred to as a "tank free" and "tankless" system), the hot melt composition is fed into a relatively small heated container (relative to a traditional hot melt application system comprising a tank) in a solid state (e.g., pellets), where the hot melt composition is melted and, typically shortly thereafter, the molten liquid is applied to the substrate. In on-demand systems, relatively large amounts of hot melt composition typically do not remain molten for a long time. In many existing on-demand systems, the volume of the molten hot melt composition is no more than about 1 liter or even no more than about 500 milliliters, and the hot melt composition remains molten for a relatively short period of time, including, for example, less than 2 hours, less than 1 hour, or even less than 30 minutes. Suitable on-demand hot melt adhesive application systems include, for example, the InvisiPac Tank-Free HotMelt Delivery System from Graco Minnesota Inc. (Minneapolis, Minnesota) and the Freedom HotMelt Dispensing System from Nordson Corporation (Westlake, Ohio). On-demand hot melt adhesive application systems are described in U.S. Patent Publication Nos. 2013-0105039, 2013-0112709, 2013-0112279, and 2014-0042182 and U.S. Patent No. 8,201,717 and are incorporated herein.

The present invention will now be described by way of the following examples. Unless otherwise specified, all parts, ratios, percentages and amounts specified in the examples are by weight.

Example

Test procedures

The test procedures used in the examples include the following. Unless otherwise indicated, all ratios and percentages are by weight. Unless otherwise specified, these procedures were carried out at room temperature (i.e., an ambient temperature of about 20° C. to about 25° C.) and ambient humidity (i.e., 30% to 70%).

Method for determining molecular weight

Molecular weights (Mn, Mw, and Mz) were determined using a Polymer Labs PL-GPC220 high-temperature size exclusion chromatography (HT-SEC) system operated at 160°C with 1,2,4-trichlorobenzene (TCB) as the mobile phase. The system contained three PL Gel Mix B columns in series and was equipped with a refractive index (RI) detector. SEC was run at a flow rate of 1.0 mL/min with an injection volume of 100 μL. All HT-SEC samples were prepared at a concentration of 4.0 mg/mL. Molecular weights were calculated using the Mark-Houwink relationship using known polystyrene standards. For polystyrene, the Mark-Houwink parameters were K = 0.000121 and α = 0.707; for polypropylene, the Mark-Houwink parameters were K = 0.000190 and α = 0.725. Results are reported in grams per mole (g/mol).

Viscosity test method

Viscosity is measured according to ASTM D-3236, entitled "Standard Test Method for Apparent Viscosity of Hot Melt Adhesives and Coating Materials," October 31, 1988, using a Brookfield viscometer, a Brookfield Thermosel heated sample cell, and a No. 27 spindle. Results are reported in centipoise (cP).

Setting time test method

Use MEC ASM-15N hot melt adhesive simulator to be measured as 5.08cm x0.24cm adhesive composition bead to be applied to the first substrate of RockTenn 56SK-23ME-56SK high performance 44 pounds ECT 87% virgin liner board at 177 ℃.After 2 seconds, the adhesive bead is applied to the first substrate, and the second substrate of the high performance 44 pounds ECT 87% virgin liner board of RockTenn 56SK-23ME-56SK is contacted. It is then pressed on the first substrate for a period of time (referred to as compression time in this article) with a pressure of 0.21MPa. The bonding simulator timer is started when the substrate is compressed. After the pre-programmed compression time, the instrument is separated by pulling the second substrate in the Z direction and the first substrate is maintained in a fixed position. The amount of the force required for separating the substrates and the fiber tearing existing on the adhesive composition is measured. The sample is run in triplicate under each compression time. Initially, the compression time is 0.5 second. If the three samples fail to exhibit greater than 50% fiber tear for each sample, increase the compression time by 0.1 seconds and repeat the test method until greater than 50% fiber tear is noted for all three samples. Record the setting time as the compression time at which greater than 50% fiber tear is achieved for the three samples immediately after separation. Record the setting time in seconds.

Thermal stress resistance test method

Heat stress resistance was measured according to standard number IOPP T-3006, entitled "Suggested Test Method for Determining the Heat Stress Resistance of Hot Melt Adhesives," using a starting temperature of 46°C (115°F), a load of 200 grams per sample, and five bonded samples of each adhesive. After each 24-hour period, the number of samples that no longer supported the weight was recorded and the temperature was increased by 2.8°C (5.0°F). The pass temperature of each adhesive, defined as the maximum temperature at which 80% of the samples remained bonded, was the heat stress resistance and was reported in degrees Celsius (°C).

Fiber tear test method

The fiber tear percentage is the fiber percentage that covers the adhesive area after two substrates that are bonded together by adhesive are separated with force before.The fiber tear percentage that adhesive composition shows is measured as follows.Use ROCKTENN bonding simulator to be measured as 15.24cm (6 inch) x0.24cm (3/32 inch) adhesive composition bead is applied to the first substrate of RockTenn 56SK-23ME-56SK 44 pounds of ECT 87% virgin liner under the specified application temperature.After adhesive bead is applied on the first substrate, 2 seconds, this adhesive bead is contacted with the second substrate of RockTenn 56SK-23ME-56SK 44 pounds of ECT87% virgin liner, and it is pressed on adhesive and the first substrate with the pressure of 0.21MPa (30 pounds per square inch (psi)) for 2 seconds.Then the gained structure is regulated at room temperature for at least 4 hours, and is regulated at least 12 hours at the specified test temperature.Then under the regulated temperature (for example, immediately after taking out sample from conditioning chamber) by hand two substrates are pulled apart mutually and the substrate of this structure is separated from each other. Observe the surface of the adhesive composition and determine and record the percentage of the surface area of the adhesive composition covered by fibers. Prepare and test a minimum of five samples for each hot melt adhesive composition. The results are reported in units of % fiber tear.

Thermal stability test method

A 200-gram sample of the hot melt adhesive composition was placed in a glass beaker (without a lid) and conditioned in a temperature-controlled forced-air oven at 177° C. for 200 hours. The molten sample was removed from the oven. The molten sample was observed for the presence of gel, surface crusting, and charring. The observations were recorded.

The samples were then tested according to the Viscosity Test Method and the measured viscosity was expressed in centipoise.

Thermal stability is determined by viscosity change and the presence or absence of charring or skinning.

Melting point test method

The melting point is determined according to ASTM D-3461 entitled "Standard Test Method for Softening Point of Asphalt and Pitch (Mettler Cup and Ball Method)" at a heating rate of 2°C per minute.

Gardner Color

The samples (in the molten state) were tested to determine the Gardner color by comparing the sample color against the Gardner color standard as described in ASTM D-1544. The comparison was made using a Gardner Delta comparator equipped with an illuminator available from Pacific Scientific (Bethesda, Maryland). The results were reported as numerical values relative to the Gardner color standard.

Examples 1-4

The hot melt adhesive compositions of Examples 1-4 were prepared by combining the amounts (wt %) and types of LINXAR 127 propylene-hexene copolymer (ExxonMobil Chemical Company, Houston, Texas), waxes, oils, and antioxidants specified in Table 1 and heating to 175°C to 190°C with mixing.

The hot melt adhesive compositions of Examples 1-4 were tested according to the viscosity, setting time, thermal stress resistance and fiber tear test methods. The results are reported in Table 1.

Table 1

Example 1 2 3 4 71.8 72 77 71 5 9.8 0 7.8 15 15 19.8 18 5 0 0 0 3 3 3 3 0 0.2 0.2 0.2 0.2 0 0 0 0 0 0 0 Viscosity@177℃(cP) 966 680 940 735 Solidification time (seconds) 1.0 1.7 1.1 1.4 Thermal stress resistance (℃) 57 63 >85 79 -29℃ 80 55 92 94 -18℃ 80 80 98 100 4℃ 100 98 100 100 49℃ 100 NT NT NT 54℃ NT 100 100 100 60℃ 100 100 100 100 66℃ NT 98 NT NT 71℃ NT 86 93 91

1 = LINXAR 127 propylene-hexene copolymer having a density of 0.860 g/cm3, a viscosity of 825 cP at 190°C, and a peak melting temperature of 125°C (ExxonMobil Chemical Company, Houston, Texas)

2＝CALSOL 550 naphthenic oil (Calumet Specialty Products Partners, LP, Indianapolis, Indiana)

3 = EPOLENE N-21 polyethylene wax (Westlake Chemical Corporation, Houston, Texas)

4 = EPOLENE N-15 polypropylene wax (Westlake Chemical Corporation)

5 = WESTLAKE E-43 maleic anhydride modified polypropylene wax (Westlake Chemical Corporation)

6 = IRGANOX 1010 hindered phenolic antioxidant (BASF Corporation, Florham Park, New Jersey)

7 = EVERNOX 10 hindered phenol antioxidant (Everspring Chemical, Taichung, Taiwan)

8 = IRGANOX 1076 hindered phenolic antioxidant (BASF Corporation, Florham Park, New Jersey)

NT = Not Tested

Examples 5-8

The hot melt adhesive compositions of Examples 5-8 were prepared by combining the amounts (wt %) and types of LINXAR 127 propylene-hexene copolymer (ExxonMobil Chemical Company, Houston, Texas), waxes, oils, antioxidants, and tackifiers specified in Table 2 and heating them to 175°C to 190°C with mixing.

The hot melt adhesive compositions of Examples 5-8 were tested according to the viscosity, setting time, thermal stress resistance and fiber tear test methods. The results are reported in Table 2.

Table 2

9 = ESCOREZ 5400 cycloaliphatic hydrocarbon resin with a Tg of 52°C (ExxonMobil

Corporation,Houston,Texas)

Examples 9-13

The hot melt adhesive compositions of Examples 9-13 were prepared by combining the amounts (wt %) and types of LINXAR 127 propylene-hexene copolymer (ExxonMobil Chemical Company, Houston, Texas), waxes, oils (when present), and antioxidants specified in Table 3 and heating them to 175° C. to 190° C. with mixing.

The hot melt adhesive compositions of Examples 9-13 were tested according to at least one of the viscosity, set time, thermal stress resistance, and fiber tear test methods. The results are reported in Table 3.

Table 3

10 = POLYWAX 3000 polyethylene wax (Baker Hughes, Houston, Texas)

11＝SX-105 Fischer-Tropsch wax (Shell Malaysia Ltd., Kuala Lumpur, Malaysia)

12＝FR-6513 paraffin wax (Calumet Specialty Products Partners, LP, Indianapolis, Indiana)

Examples 14-17

The hot melt adhesive compositions of Examples 14-17 were prepared by combining the amounts (weight %) and types of components specified in Table 4 and heating them to 175°C to 190°C with mixing.

The hot melt adhesive compositions of Examples 14-17 were tested according to at least one of the viscosity, set time, thermal stress resistance, and fiber tear test methods. The results are reported in Table 4.

Table 4

13 = VISTAMAXX 8880 metallocene-catalyzed propylene-ethylene copolymer (ExxonMobil Chemical Company, Houston, Texas)

14 = VISTAMAXX 3980FL metallocene-catalyzed polypropylene elastomer (ExxonMobil)

15 = VISTAMAXX 6202 propylene-ethylene copolymer (ExxonMobil)

16 = KRATON G1657 styrene-ethylene-butylene-styrene block copolymer (Kraton Polymers LLC, Houston, Texas)

17 = ESCOREZ 5637 aromatic modified alicyclic hydrocarbon resin (ExxonMobil)

18 = AC 596P maleated polyethylene wax (Honeywell International Inc., Morristown, New Jersey)

19＝SARAWAX SX 105 Fischer-Tropsch wax (Shell Malaysia Ltd., Kuala Lumpur, Malaysia)

Examples 18 and 19

The hot melt adhesive compositions of Examples 18 and 19 were prepared by combining the amounts (weight %) and types of components specified in Table 5 and heating them to 175°C to 190°C with mixing.

The hot melt adhesive compositions of Examples 18 and 19 were tested according to at least one of the viscosity, set time, and fiber tear test methods. The results are reported in Table 5.

Table 5

Examples 20-22

The hot melt adhesive compositions of Examples 20-22 were prepared by combining the amounts (weight %) and types of components specified in Table 6 and heating them to 175°C to 190°C with mixing.

The hot melt adhesive compositions of Examples 20-22 were tested according to at least one of the viscosity, set time, and fiber tear test methods. The results are reported in Table 6.

Table 6

20＝RESINAL R1030(Resinall Corp,Severn,North Carolina)

Additional embodiments are within the claims.All documents cited herein are incorporated in their entirety.

1. A hot melt adhesive composition comprising at least 40 wt. % of an unmodified semi-crystalline propylene polymer comprising at least 50 wt. % propylene, at least 15 wt. % of a non-functionalized wax, and no greater than 8 wt. % of an ethylene-ethylenically unsaturated ester copolymer, wherein the non-functionalized wax comprises a first non-functionalized wax and a second non-functionalized wax different from the first non-functionalized wax.

2. A hot melt adhesive composition comprising at least 40 wt% of an unmodified semi-crystalline propylene polymer comprising at least 50 wt% propylene, at least 15 wt% of a non-functionalized wax, 0 wt% to no more than 10 wt% of a functionalized wax, and 1 wt% to 10 wt% of an elastomeric block copolymer comprising styrene.

3. A hot melt adhesive composition comprising at least 55 wt% of a semi-crystalline propylene polymer comprising at least 50 wt% propylene and greater than 20 wt% of a wax, the wax comprising a first wax, a second wax different from the first wax, and 0 wt% to no more than 10 wt% of a functionalized wax, based on the weight of the hot melt adhesive composition, the hot melt adhesive composition exhibiting a set time of no more than 2 seconds.

4. The hot melt adhesive composition of any of paragraphs 1 and 3, further comprising an elastomeric block copolymer comprising styrene.

5. The hot melt adhesive composition of any of paragraphs 2 and 4, wherein the elastomeric block copolymer is selected from the group consisting of styrene-ethylene/butylene-styrene block copolymers, styrene-ethylene/propylene-styrene block copolymers, and combinations thereof.

6. The hot melt adhesive composition of any of paragraphs 1 to 5, comprising at least 45 wt.% of an unmodified semi-crystalline propylene polymer.

7. The hot melt adhesive composition of any of paragraphs 1 to 5, comprising at least 50 wt.% of an unmodified semi-crystalline propylene polymer.

8. The hot melt adhesive composition of any of paragraphs 1 to 5, comprising at least 55 wt% of an unmodified semi-crystalline propylene polymer.

9. The hot melt adhesive composition of any of paragraphs 1 to 8, wherein the first non-functionalized wax comprises a polyethylene wax, a Fischer-Tropsch wax, or a combination thereof.

10. The hot melt adhesive composition of any of paragraphs 1 to 9, wherein the first non-functionalized wax has a melting point greater than 100°C.

11. The hot melt adhesive composition of any of paragraphs 1-10, wherein the second non-functionalized wax has a melting point greater than 115°C.

12. The hot melt adhesive composition of any of paragraphs 1 to 11, further comprising a functionalized wax.

13. The hot melt adhesive composition of paragraph 12, wherein the first non-functionalized wax comprises a polyethylene wax, a Fischer-Tropsch wax, or a combination thereof, and the functionalized wax comprises a maleated polyethylene wax, a maleated polypropylene wax, or a combination thereof.

14. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-13, comprising greater than 20 wt.% wax.

15. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-15, wherein the unmodified semi-crystalline propylene polymer has a heat of fusion of 15 J/g to no greater than 50 J/g.

16. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-15, wherein the composition exhibits a set time of no greater than 2 seconds.

17. The hot melt adhesive composition of any of paragraphs 1-16, wherein the composition exhibits a thermal stress resistance greater than 60°C and a set time no greater than 2 seconds.

18. The hot melt adhesive composition of any of paragraphs 1-17, wherein the composition exhibits a thermal stress resistance greater than 60°C, greater than 50% fiber tear at 4°C and greater than 50% fiber tear at 60°C, and a set time no greater than 1.5 seconds.

19. The hot melt adhesive composition of any of paragraphs 1-17, wherein the composition exhibits a thermal stress resistance greater than 71°C, greater than 50% fiber tear at 4°C and greater than 50% fiber tear at 71°C, and a set time of no greater than 1.5 seconds.

20. The hot melt adhesive composition of any of paragraphs 1-17, wherein the composition exhibits a thermal stress resistance greater than 71°C, greater than 50% fiber tear at -18°C and greater than 50% fiber tear at 71°C, and a set time of no greater than 1.5 seconds.

21. The hot melt adhesive composition of any of paragraphs 1-20, further comprising an oil, a polybutene, or a combination thereof.

22. The hot melt adhesive composition of any of paragraphs 1-20, wherein the composition exhibits a viscosity of no greater than 2000 centipoise at 177°C.

23. The hot melt adhesive composition of any of paragraphs 1 to 22, comprising 45 wt% to about 70 wt% unmodified semi-crystalline propylene polymer, about 20 wt% to about 35 wt% non-functionalized wax, and 0 wt% to about 10 wt% functionalized wax.

24. The hot melt adhesive composition of any of paragraphs 1-17 and 21-23, wherein the composition exhibits a set time of no greater than 1.5 seconds.

25. The hot melt adhesive composition of any of paragraphs 1-17 and 21-23, wherein the composition exhibits a set time of no greater than 1 second.

26. The hot melt adhesive composition of any of paragraphs 1 to 25, comprising 50% to about 65% by weight of the unmodified semi-crystalline polypropylene polymer.

27. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-26, wherein the unmodified semi-crystalline propylene polymer comprises an unmodified, metallocene-catalyzed semi-crystalline propylene polymer, an unmodified, non-metallocene heteroaryl-catalyzed semi-crystalline propylene polymer, or a combination thereof.

28. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-27, wherein the unmodified semi-crystalline propylene polymer comprises an unmodified, metallocene-catalyzed semi-crystalline propylene copolymer, an unmodified, non-metallocene heteroaryl-catalyzed semi-crystalline propylene copolymer, or a combination thereof.

29. The hot melt adhesive composition of any of paragraphs 1, 2, and 4-28, wherein the unmodified semi-crystalline propylene polymer exhibits a viscosity of no greater than 1200 cP at 190°C.

30. The hot melt adhesive composition of any of paragraphs 1-29, wherein the composition exhibits a thermal stress resistance greater than 60°C, greater than 50% fiber tear at -18°C, and greater than 50% fiber tear at 60°C.

31. The hot melt adhesive composition of any of paragraphs 1-30, wherein the composition exhibits a viscosity of no greater than 1500 centipoise at 149°C.

32. The hot melt adhesive composition of any of paragraphs 1 to 31, wherein the non-functionalized wax comprises a first non-functionalized wax and a second non-functionalized wax different from the first non-functionalized wax.

33. The hot melt adhesive composition of any of paragraphs 1-32, further comprising 15% to 30% by weight of a tackifier.

34. A package comprising the hot melt adhesive composition of any of paragraphs 1 to 33, a first substrate comprising fibers, and a second substrate comprising fibers, the second substrate being bonded to the first substrate by the adhesive composition.

Claims (14)

1. A hot melt adhesive composition comprising: At least 40% by weight of a first unmodified semi-crystalline propylene polymer containing at least 50% by weight of propylene; At least 20% by weight of a nonfunctionalized wax, said nonfunctionalized wax comprising 1% to 30% by weight of Fischer-Tropsch wax based on the weight of the hot melt adhesive composition; and 1% to 30% by weight of polyethylene wax based on the weight of the hot melt adhesive composition; 10% to 30% by weight of tackifier; 4% to 10% by weight of styrene-containing elastomeric block copolymers; and 0% to 8% by weight of ethylene-olefinic unsaturated ester copolymers; The sum of the weight percentages of the components in the adhesive composition is 100% by weight; and The adhesive composition exhibits a curing time of no more than 1.5 seconds. 2. The hot melt adhesive composition of claim 1, comprising: 55% to 70% by weight of the unmodified semi-crystalline propylene polymer; 20% to 35% by weight of the aforementioned nonfunctionalized wax; and It further contains 0% to 10% by weight of functionalized wax. 3. The hot melt adhesive composition of claim 1, wherein the unmodified semi-crystalline propylene polymer has a heat of fusion of 15 J/g to no more than 50 J/g. 4. The hot melt adhesive composition of claim 1, wherein the composition exhibits a fiber tear rate of greater than 50% at 4°C and greater than 50% fiber tear rate at 60°C and a setting time of not more than 1.5 seconds. 5. The hot melt adhesive composition of claim 1, wherein the unmodified semi-crystalline propylene polymer is selected from unmodified metallocene-catalyzed propylene copolymers, unmodified non-metallocene heteroaryl-catalyzed propylene copolymers, and combinations thereof. 6. The hot melt adhesive composition of claim 1, wherein the styrene-containing elastomeric block copolymer is selected from styrene-ethylene/butene-styrene block copolymer, styrene-ethylene/propylene-styrene block copolymer, styrene-isoprene-styrene copolymer, styrene-butadiene-styrene copolymer, and combinations thereof. 7. A hot melt adhesive composition comprising: At least 55% by weight of an unmodified semi-crystalline propylene polymer selected from propylene-hexene copolymers, semi-crystalline propylene homopolymers, and combinations thereof containing at least 50% by weight of propylene; Wax greater than 20% by weight, The wax comprises at least 7% by weight of nonfunctionalized polyethylene wax based on the weight of the binder composition. Fischer-Tropsch wax, and 0% by weight to no more than 10% by weight of functionalized wax, based on the weight of the hot melt adhesive composition; and 4% to 10% by weight of styrene-containing elastomeric block copolymers, The sum of the weight percentages of the components in the adhesive composition is 100% by weight; and The hot melt adhesive composition exhibits a setting time of no more than 2 seconds. 8. The hot melt adhesive composition of claim 7, wherein the styrene-containing elastomeric block copolymer is selected from styrene-ethylene/butene-styrene block copolymer, styrene-ethylene/propylene-styrene block copolymer, styrene-isoprene-styrene copolymer, styrene-butadiene-styrene copolymer, and combinations thereof. 9. The hot melt adhesive composition of claim 7, wherein the unmodified semi-crystalline propylene polymer has a heat of fusion of 15 J/g to no more than 50 J/g. 10. The hot melt adhesive composition of claim 7, wherein the composition exhibits a fiber tear rate of greater than 50% at 4°C and greater than 50% fiber tear rate at 60°C and a setting time of not more than 1.5 seconds. 11. The hot melt adhesive composition of claim 7, wherein the unmodified semi-crystalline propylene polymer is selected from unmodified metallocene-catalyzed propylene-ethylene copolymers, unmodified non-metallocene heteroaryl-catalyzed propylene-ethylene copolymers, and combinations thereof. 12. A package comprising: The hot melt adhesive composition according to any one of claims 1-11; The first substrate containing fibers; and A second substrate containing fibers is bonded to a first substrate by the adhesive composition. 13. A hot melt adhesive composition comprising: At least 40% by weight of a first unmodified semi-crystalline propylene polymer containing at least 50% by weight of propylene; At least 20% by weight of a nonfunctionalized wax, said nonfunctionalized wax comprising 1% to 30% by weight of Fischer-Tropsch wax based on the weight of the hot melt adhesive composition; and 1% to 30% by weight of polyethylene wax based on the weight of the hot melt adhesive composition; 10% to 30% by weight of tackifier; and 0% to 8% by weight of ethylene-olefinic unsaturated ester copolymers; The adhesive composition exhibits a curing time of no more than 1.5 seconds. 14. The hot melt adhesive composition of claim 13, further comprising: 1% to 10% by weight of a styrene-containing elastomeric block copolymer.