WO2022120357A1

WO2022120357A1 - Sustainable reactive hot melt adhesive compositions

Info

Publication number: WO2022120357A1
Application number: PCT/US2021/072688
Authority: WO
Inventors: Laurent CHALUMEAU; Marietta Helmeke
Original assignee: H.B. Fuller Company
Priority date: 2020-12-02
Filing date: 2021-12-02
Publication date: 2022-06-09
Also published as: EP4255951A1

Abstract

The invention features a reactive hot melt adhesive composition derived from diisocyanate, from 20% by weight to 85% by weight of a bio-based polyol, and from 1% by weight to 60% by weight of a recycled polyol.

Description

SUSTAINABLE REACTIVE HOT MELT ADHESIVE COMPOSITIONS

The invention is directed to sustainable reactive hot melt adhesive compositions.

Reactive hot melt adhesive compositions have been used in a wide variety of applications to form strong permanent bonds between various substrates.

Reactive hot melt adhesive compositions are commonly based on isocyanate terminated polyurethane prepolymers that react with surface or ambient moisture to chainextend, forming a urethane-urea polymer. These polyurethane prepolymers are traditionally produced using petrol-based raw materials.

End users have begun to request reactive hot melt adhesive compositions with increased sustainable content that have similar performance as compared to petrol-based reactive hot melt adhesive compositions.

SUMMARY

In one aspect, the invention features a reactive hot melt adhesive composition derived from diisocyanate, 20% by weight to 85% by weight of a bio-based polyol, and 1% by weight to 60% by weight, or even from 3% by weight to 60% by weight of a recycled polyol.

In one embodiment, the reactive hot melt adhesive composition includes from 90% by weight to 100% by weight, or even from 95% by weight to 100% by weight of the total of the bio-based polyol, the recycled polyol and the isocyanate.

In another embodiment, the bio-based polyol is present at from 40% by weight to 80% by weight and the recycled polyol is present at from 3% by weight to 10% by weight.

In a different embodiment, the reactive hot melt adhesive composition is derived solely from sustainable polyols.

In one embodiment, the reactive hot melt adhesive composition has a sustainable component content of from 75% by weight to 100% by weight.

In a different embodiment, the reactive hot melt adhesive composition has a monomeric diisocyante content of no greater than 10% by weight, no greater than 0.5% by weight, or even less than 0.1% by weight. In another embodiment, the bio-based polyol is a polyester derived from a material selected from the group consisting of millet, corn, castor oil, sugar and wheat. In a different embodiment, the bio-based polyol has a bio-based carbon content according to ASTM 6866- 20 of from 60% to 100% based on the total carbon content. In still another embodiment, the recycled polyol is derived from recycled polyethylene terephthalate. In another embodiment, the diisocyanate is bio-based. In a different embodiment, the diisocyanate is sustainable through biomass balance method. In a different embodiment, the bio-based polyol includes an amorphous polyol and a crystalline polyol.

In another embodiment, the reactive hot melt adhesive composition further includes a thermoplastic polymer selected from the group consisting of polyester and polyurethane.

In another aspect, the invention features a laminate including the cured reactive hot melt adhesive composition, a first substrate and a second substrate adhered to the first substrate through the cured adhesive composition.

In one embodiment, the laminate comprises a multi-layer textile. In another embodiment, at least one of the first substrate and the second substrate are selected from the group consisting of recycled and bio-based. In a different embodiment, at least one of the first substrate and the second substrate is recycled.

In another embodiment, the invention features a reactive hot melt adhesive composition including from 80% by weight to 100% by weight of a polyurethane prepolymer comprising the reaction product of diisocyanate, a bio-based polyol, and a recycled polyol, wherein the polyurethane prepolymer is derived solely from sustainable polyols.

It can be difficult to formulate reactive hot melt adhesive compositions using high percentages of sustainable materials as often there are not direct substitutes for the petrolbased materials (i.e. materials derived from petroleum based feed stocks). Further, consumers have a desire for compositions formed from recycled materials. Recycled materials are derived from previously used materials and are often considered more desirable as they promote a circular economy, where materials are used and reused as often as possible.

However, since the type of polyols based on recycled materials are limited, the inventors have discovered that by blending polyols derived from recycled content and biobased polyols, the properties of the reactive hot melt can be adjusted in such a way that in some cases, petrol based polyols are not required. In other cases, a limited amount of petrol based materials can be added to balance required properties. Other features and advantages will be apparent from the following description of the preferred embodiments and from the claims.

DEFINITIONS

“Renewable” is used herein to refer to a resource that is produced by a natural process at a rate comparable to its rate of consumption. The resource can be replenished naturally or by engineered agricultural techniques. Examples of renewable resources include but are not limited to plants (e.g., sugar cane, sugar beets, corn, wheat, potatoes, citrus fruit (e.g. oranges), woody plants, cellulosic waste, etc.), animals, fish, bacteria, fungi, and forestry products (e.g. pine and spruce trees). These resources can be naturally occurring, hybrids, or genetically engineered organisms. The definition of renewable raw materials further includes raw materials, in which the bio-based origin cannot be detected by the radiocarbon method (ASTM 6866-20) due to time or dilution effects, but is demonstrated and allocated by relevant biomass balance (BMB) methods.

Natural resources such as crude oil, coal and natural gas are not considered renewable as they are derived from materials that will run out or will not be replenished for thousands or even millions of years.

“Bio-based” is used herein to refer to a material that is produced or is derived from at least 25% by weight of a renewable material.

“Recycled” is used herein to refer to a material that is produced or is derived from at least 25% by weight of a recycled material

“Sustainable” is used herein to refer to a material that is selected from the group consisting of bio-based and recycled.

All percents are in weight percent and are based on the total amount of material in the reactive hot melt adhesive composition.

DETAILED DESCRIPTION

REACTIVE HOT MELT ADHESIVE COMPOSITION

The invention features a reactive hot melt adhesive composition derived from diisocyanate, 20% by weight to 85% by weight of a bio-based polyol, and 1% by weight to 60% of a recycled polyol. The invention further features a reactive hot melt adhesive composition derived from diisocyanate, 50% by weight to 85% by weight of a bio-based polyol, and from 3% by weight to 20% by weight of a recycled polyol.

The invention further features a reactive hot melt adhesive composition including from 80% by weight to 100% by weight of a polyurethane prepolymer comprising the reaction product of diisocyanate, a bio-based polyol, and a recycled polyol, wherein the polyurethane prepolymer is derived solely from sustainable polyols.

The diisocyanate, bio-based polyol and recycled polyol are generally pre-reacted to form a polyurethane prepolymer to which additional raw materials e.g. thermoplastic polymers, additives, etc. can be added, to form the final reactive hot melt adhesive composition.

The reactive hot melt adhesive compositions of this invention can include a high weight percent of sustainable components. The reactive hot melt adhesive compositions can include from 50% by weight to 100% by weight, from 65% by weight to 100% by weight, from 75% by weight to 100% by weight, or even from 80% by weight to 100% by weight of sustainable components.

The reactive hot melt adhesive composition can have a monomeric diisocyanate content of no greater than 10% by weight, no greater than 7.5% by weight, no greater than 5% by weight, no greater than 1% by weight, no greater than 0.5% by weight, from 0.0% by weight 7.5% by weight, from 0.0% by weight to 5% by weight, or even less than 0.1% by weight, as tested according to the CURRENT A HPLC-MS/MS CAM-0642303 -18E - FEICA Test Method.

The reactive hot melt adhesive composition is solid at room temperature. By solid it is meant that it is not a liquid. The reactive hot melt adhesive composition preferably exhibits an initial viscosity of no greater than 20,000 centipoise (cP), no greater than 15,000 cP, no greater than 10,000 cP, from 1,000 cP to 20,000 cP, or even from 5,000 cP to 15,000 cP at 120 °C.

The reactive hot melt adhesive composition can be free of petrol based polyols. In other cases, the reactive hot melt adhesive composition can include a limited amount of petrol based polyol. The reactive hot melt adhesive composition can include no greater than 40% by weight, no greater than 35% by weight, no greater than 20%, no greater than 10%, from 5% by weight to 40% by weight, from 5% by weight of 30% by weight or even from 5% by weight to 20% of a petrol based polyol.

POLYURETHANE PREPOLYMER

The reactive hot melt adhesive composition includes one or more polyurethane prepolymers. The polyurethane prepolymer is generally isocyanate terminated. The reactive hot melt adhesive composition can include one prepolymer derived from diisocyanate, biobased polyol and recycled polyol. Alternatively, the reactive hot melt adhesive composition can include more than one prepolymer e.g. one prepolymer derived from diisocyanate and bio-based polyol and a second prepolymer derived from diisocyanate and recycled polyol.

The polyurethane prepolymer can have a monomeric diisocyanate content of no greater than 10% by weight, no greater than 7.5% by weight, no greater than 5% by weight, no greater than 1% by weight, no greater than 0.5% by weight, from 0.0% by weight 7.5% by weight, from 0.0% by weight to 5% by weight, or even less than 0.1% by weight, as tested according to the CURRENT A HPLC-MS/MS CAM-0642303 -18E - FEICA Test Method.

The reactive hot melt adhesive composition can include from 80% by weight to 100% by weight, from 90% by weight to 100% by weight, or even from 95% by weight to 100% by weight of the polyurethane prepolymer.

In a preferred embodiment, the reactive hot melt adhesive composition includes one polyurethane prepolymer derived solely from polyols that are sustainable. By derived solely, it is meant that non-sustainable polyols are not used.

BIO-BASED POLYOL

The bio-based polyol can include more than one bio-based polyol. The bio-based polyol can be an amorphous liquid. The bio-based polyol can include both an amorphous polyol and a crystalline polyol. The amorphous polyol can be liquid or solid. The crystalline polyol is typically a solid. In a preferred embodiment, the crystalline polyol is a polyester polyol.

The bio-based polyol is selected from the group consisting of polyether polyol and polyester polyol but is preferably includes at least one polyester polyol. The bio-based polyol can be derived from e.g. soybean, millet, nuts (e.g. cashew nuts, etc.), corn, potatoes, citrus fruit (e.g. oranges), woody plants, cellulosic waste, etc., animals, fish, bacteria, fungi, forestry products (e.g. pine and spruce trees, tall oil, castor oil, sugar (sugar beets, sugar cane, etc.), wheat, or any other renewable material.

The bio-based polyol is produced or is derived from at least 25% by weight, at least 30% by weight, at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, from 25% by weight to 100% by weight, from 50% by weight to 100% by weight, from 70% by weight to 100% by weight, from 90% by weight to 100% by weight, or even 100% by weight of a renewable material.

The bio-based polyol can have bio-based carbon content according to ASTM 6866-20 of at least 25% by weight, at least 30% by weight, at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, from 25% by weight to 100% by weight, from 50% by weight to 100% by weight, from 70% by weight to 100% by weight, from 90% by weight to 100% by weight, or even 100% by weight based on the total carbon content.

Useful bio-based polyols include polyols available under the BIO-HOOPOL designation including BIO-HOOPOL 11034 (an amorphous liquid polyester polyol with a Bio-based Carbon content = 64.2% by ASTM 6866-20 and BIO-HOOPOL 11003 (a crystalline solid polyester polyol with a Bio-based Carbon content = 100% by ASTM 6866- 20), polyols available from Synthesia Technology (Barcelona, Spain) and under the DYNACOLL TERRA designation including DYNACOLL TERRA EP 481.01, a crystalline solid polyester, made from 100% renewable resources available from Evonik Gmbh (Germany) and liquid poly ether polyols, made from 100% renewable resources available under the VELVETOL designation including VELVETOL H-1000 AND VELVETOL H- 2000 available from Allessa GmbH (Frankfort, Germany) .

The polyurethane prepolymer can be derived from 20% by weight to 85% by weight, from 30% by weight to 80% by weight, or even from 40% by weight to 80% by weight of the bio-based polyol.

The reactive hot melt adhesive composition can be derived from 20% by weight to 85% by weight, from 30% by weight to 80% by weight, or even from 40% by weight to 80% by weight of the bio-based polyol. RECYCLED POLYOL

The recycled polyol can include more than one recycled polyol. The recycled polyol can be an amorphous solid. The recycled polyol can improve the strength of the reactive hot melt adhesive composition.

The recycled polyol can be derived from recycled polycarbonate, recycled polyethylene terephthalate (PET), or any other recycled material.

Recycled polycarbonate can come from scrap polycarbonate recovered from containers, compact discs, construction materials, eyeglasses, consumer electronics or other sources.

Recycled PET can come from a variety of waste sources. The most common is the post-consumer waste stream of PET from plastic bottles or other containers.

The recycled polyol is derived from at least 25% by weight of a recycled material, but can be preferably derived from at least 30% by weight, at least 35% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, from 25% by weight to 100% by weight, from 35% by weight to 100% by weight, from 50% by weight to 100% by weight, from 75% by weight to 100% by weight or even 100% by weight of a recycled material.

Useful recycled polyols include polyols available under the HOOPOL designation including HOOPOL F-39037 (38% by weight Post-Consumer Recycled PET by ISO 14021 :2016) available from Synthesia Technology (Barcelona, Spain).

The polyurethane prepolymer can be derived from 1% by weight to 60% by weight, from 3% by weight to 60% by weight, from 3% by weight to 40%, from 3% by weight to 30% by weight, from 1% by weight to 20% by weight, from 3% by weight to 20% by weight, from 1% by weight to 10% by weight, or even from 3% by weight to 10% by weight of the recycled polyol.

The reactive hot melt adhesive composition can be derived from 1% by weight to 60% by weight, from 3% by weight to 60% by weight, from 3% by weight to 40%, from 3% by weight to 30% by weight, from 1% by weight to 20% by weight, from 3% by weight to 20% by weight, from 1% by weight to 10% by weight, or even from 3% by weight to 10% by weight of the recycled polyol. DIISOCYANATE

The diisocyanate can be liquid or solid at room temperature. The diisocyanate can be based on renewable materials, such as a bio-based difurfuryl diisocyanate, bio-based dimeryl diisocyanate, or other renewable diisocyanate. The diisocyanate can be sustainable through a biomass balance method. The diisocyanate can be a blend of more than one diisocyanate.

Additional useful diisocyanates include, e.g., monomeric diisocyanates and oligomeric diisocyanates. The diisocyanate can be any suitable diisocyanate including, e.g., monomeric diisocyanates, oligomeric diisocyanates, aromatic diisocyanates, aliphatic diisocyanates, clycloaliphatic diisocyanates, and combinations thereof. Useful aromatic diisocyanates include, e.g., diphenyl methylene diisocyanate (MDI), (e.g., diphenylmethane-2,4'- diisocyanate (i.e., 2,4'-MDI), diphenylmethane-2,2'-diisocyanate (i.e., 2,2'-MDI), diphenylmethane-4,4'-diisocyanate (i.e., 4,4’-MDI), and combinations thereof), tetramethylxylene diisocyanate, naphthalene diisocyanate (e.g., naphthalene-l,5-diisocyanate, naphthal ene-l,4-diisocyanate, and combinations thereof), toluene diisocyanate (TDI) (e.g., 2,4-TDI, 2,6-TDI, and combinations thereof), and combinations thereof. Useful cycloaliphatic diisocyanates include, e.g., l-isocyanatomethyl-3-isocyanato-l,5,5-trimethyl- cyclohexane (i.e., isophorone diisocyanate (i.e., IPDI)), l-methyl-2,4-diisocyanato- cyclohexane, l,4-diisocyanato-2,2,6-trimethylcyclohexane (i.e., TMCDI), hydrogenation products of the aforementioned aromatic diisocyanates (e.g., hydrogenated 2,4'-MDI, hydrogenated 2,2'-MDI, hydrogenated 4,4’-MDI and combinations thereof), and combinations thereof. Useful aliphatic diisocyanates include, e.g., hexamethylene diisocyanate (HDI) (e.g., l,6-diisocyanato-2,2,4-trimethylhexane, l,6-diisocyanato-2,4,4-trimethylhexane diisocyanate, and combinations thereof), lysine diisocyanate, dodecane diisocyanate and combinations thereof.

Preferably the diisocyanate is monomeric isocyanate. Useful diisocyanate monomers are commercially available under a variety of trade designations including, e.g., under the DESMODUR and MODUR series of trade designations from COVESTRO LLC (Pittsburgh, Pennsylvania) including, e.g., MODUR M, 4,4’-MDI, LUPRANATE M, 4,4’-MDI from BASF Corp. (Wyandotte, Michigan), RUB INATE 44 from Huntsman Corp. (Auburn Hills, Michigan), ONGRONAT 3000, a 4,4-MDI available from Wanhua Chemical Group (Yantai, China), ISONATE M 125 from The Dow Chemical Company (Midland, Michigan), DDI 1410, a dimeryl diisocyanate, from BASF Corp. (Wyandotte, Michigan),

The polyurethane prepolymer can be derived from 5% by weight to 35% by weight, from 10% by weight to 30% by weight, or even from 10% by weight to 20% by weight diisocyanate.

The reactive hot melt adhesive composition can be derived from 5% by weight to 35% by weight, from 10% by weight to 30% by weight, or even from 10% by weight to 20% by weight diisocyanate.

CATALYST

The reactive hot melt adhesive composition optionally includes a catalyst to increase the cure reaction rate. Useful catalysts include ether and morpholine functional groups, examples of which include di (2,6-dimethyl morpholinoethyl) ether and 4,4'-(oxydi-2,l- ethanediyl)bis-morpholine (DMDEE). Suitable commercially available catalysts include, e.g., JEFFCAT DMDEE 4,4'-(oxydi-2,l -ethanediyl) bis-morpholine, which is available from Huntsman Corp. (Houston, Texas). Other suitable catalysts include, e.g., metallic carboxylates and dibutyl tin dilaurate. Useful metallic carboxylates include, e.g., cobalt carboxylates, manganese carboxylates, and mixtures thereof.

When a catalyst is present, the reactive hot melt adhesive composition includes from about 0.01 % by weight to about 0.5 % by weight catalyst.

THERMOPLASTIC POLYMER

The reactive hot melt adhesive compositions of this invention can optionally include a thermoplastic polymer. The thermoplastic polymer includes thermoplastic polymers with a limited OH value, such as e.g. an OH value of < 10, or even < 5.

The thermoplastic polymer can be selected from the group consisting of polyesters (e.g. caprolactone) and thermoplastic polyurethane.

The thermoplastic polymer can have a Weight Average Molecular Weight (Mw) of from 10,000 to 50,000 or even from 15,000 to 40,000.

Useful thermoplastic polymers include those sold under the CAPA trade designation including CAPA 6400 and CAPA 6500 available from Ingevity (Brussels, Belgium). The thermoplastic polymers can be present in the reactive hot melt adhesive composition at from 3% by weight to 20% by weight, at from 4% by weight to 15% by weight, from 3% by weight to 12% by weight, or even from 3% by weight to 10% by weight.

ADDITIONAL COMPONENTS

The reactive hot melt adhesive composition optionally includes a variety of additional components including, e.g., antioxidants, stabilizers, additional polymers, tackifying agents, isocyanate trimers (e.g. DESMODUR N3300, an HDI-trimer, DESMODUR ECO N7300, a bio-based PDI-trimer available from BASF Corp. (Wyandotte, Michigan), adhesion promoters, ultraviolet light stabilizers, UV brighteners, rheology modifiers, corrosion inhibitors, colorants (e.g., pigments and dyes), fillers, nucleating agents, and combinations thereof.

Likewise, the polyurethane prepolymer can optionally be derived in part from additional polyols including petrol-based polyols, e.g., polyester polyols e.g. crystalline polyester polyols, polyether polyols, and combinations thereof. Useful petrol-based polyols include those sold under the DYNACOL trade designation, including DYNACOL 7130, an amorphous polyester polyol available from Evonik Gmbh (Germany), those sold under the PIOTHANE trade designation, including PIOTHANE 3500 EAT, a liquid polyester polyol and PIOTHANE 3500 HA, a crystalline polyester polyol both available from Specialty Resins (Auburn, ME) and those sold under the VORANOL trade designation, including VORANOL CP 755, a polyether triol, available from The Dow Chemical Company (Midland, Michigan).

Useful antioxidants include, e.g., pentaerythritol tetrakis[3,(3,5-di-tert-butyl-4- hydroxyphenyl)propionate], 2,2'-methylene bis(4-methyl-6-tert-butylphenol), phosphites including, e.g., 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 commercially available under a variety of trade designations including, e.g., the IRGANOX series of trade designations including, e.g., IRGANOX 1010, IRGANOX 565, and IRGANOX 1076 hindered phenolic antioxidants, and IRGAFOS 168 phosphite antioxidant, all of which are available from BASF Corporation (Florham Park, New Jersey), and ETHYL 702 4,4'-methylene bis(2,6-di-tert-butylphenol), which is available from Albemarle Corporation (Baton Rouge, Louisiana). When present, the reactive hot melt adhesive composition includes from 0 % by weight to 3 % by weight, or even from 0.1 % by weight to 2 % by weight antioxidant.

USES

The reactive hot melt adhesive compositions are useful in a variety of applications including, e.g., bonding two substrates together to form a laminate.

The reactive hot melt adhesive composition can be formulated to be suitable for use in bonding substrates of a variety of forms including, e.g., nonwovens (e.g., spun bond, melt- blown, staple, flashspun, and air-laid nonwovens), wovens (e.g., woven fabrics), knitted fabrics, foams, membranes (e.g., microporous membranes, nonporous membranes, monolithic membranes, and combinations thereof), fibers (e.g. natural or synthetic), threads, yams, filaments, felts, sheets (e.g., metal sheet, polymer sheet, glass sheet, continuous sheets, discontinuous sheets, and combinations thereof), films (e.g., polymer film, metallized polymer film, continuous films, discontinuous films, and combinations thereof), foils (e.g., metal foil), textiles (e.g., single layer, multilayer, woven, nonwoven, knitted fabrics, films, metal foils, membranes, foams, and combinations thereof), and combinations thereof.

Suitable substrates are derived from a variety of components including, e.g., cotton, wool, silk, leather, polyester, polyamide (e.g. Nylon-6 and Nylon-6, 6), polyurethane, thermoplastic polyurethane, polyether-polyurea copolymer (e.g. Spandex), polytetrafluoroethylene, other polymers (e.g., polycarbonate, polyolefin (e.g., polypropylene, polyethylene, low density polyethylene, linear low density polyethylene, high density polyethylene, and oriented polypropylene, copolymers of polyolefins and other comonomers), ethylene-vinyl acetate, ethylene-methacrylic acid ionomers, ethylene-vinyl-alcohols, polycarbonates, polyvinyl chloride (PVC), poly vinylidene chloride, cellulosics (e.g., Rayon, nitrocellulose, and cellulose acetate), polystyrene, and epoxy), elastomer (e.g., butyl rubber, styrene-butadiene-styrene, styrene-isoprene-styrene, styrene-ethylene/propylene-styrene and styrene- ethyl ene/butylene- styrene) polymer composites (e.g., composites of polymer and fiber, metal, cellulose, glass, polymer, and combinations thereof), metal (aluminum, copper, zinc, lead, gold, silver, platinum, and magnesium, and metal alloys such as steel, tin, brass, and magnesium and aluminum alloys), carbon-fiber composite, other fiber-based composite, graphene, fillers, glass (e.g., alkali-aluminosilicate toughened glass and borosilicate glass), quartz, boron nitride, gallium nitride, sapphire, silicon, carbide, ceramic and combinations thereof.

In a preferred embodiment, the reactive hot melt adhesive compositions are useful in bonding sustainable substrates together, such as for example substrates formed from cotton, linen, bamboo, starch, natural yarns, recycled materials (e.g. recycled PET), poly lactic acid (PLA), polyhydroxy alkanoate (PHA), poly butylene adipate terephthalate (PB AT), or any other sustainable material.

The sustainable substrates can be formed from a group selected from a recycled material and a bio-based material. The sustainable substrates can have a sustainable content of from 25% by weight to 100% by weight, from 65% by weight to 100% by weight, from 75% by weight to 100% by weight, from 80% by weight to 100%, from 90% by weight to 100% by weight or even 100% by weight.

The reactive hot melt adhesive composition can be formulated to be suitable for use in bonding substrates having a variety of properties including, e.g., porous substrates (e.g., breathable and microporous substrates), monolithic substrates, flexible substrates (i.e., the substrate can be bent using no greater than the force of two hands), rigid substrates (i.e., the substrate cannot be bent by an individual using two hands or will break if an attempt is made to bend the substrate with two hands), polar substrates, nonpolar substrates, waterproof substrates, hydrophobic substrates, hydrophilic substrates, chemical resistant substrates, elastomeric substrates, conductive substrates, insulating substrates, transparent substrates, substrates that exhibit biocide properties, and combinations thereof.

The reactive hot melt adhesive composition is suitable for use in a variety of industrial applications including, e.g., textiles (e.g., adhering layers of textile materials (e.g., woven, knitted, and nonwoven fabrics), textile to textile, textile to membrane, textile to foam, and combinations thereof). The textiles can be used in apparel, e.g. lingerie, workwear, sportwear, rainwear, footwear, etc. The reactive hot melt adhesive compositions can further be used for components of automobiles, sealing components of automobiles, applications in the automotive industry (e.g., vehicle construction (e.g., head liner)), recreational vehicles, appliances, filters, electronic assemblies, wood materials, plastic materials, laminated panels, edge-banding, profile wrapping, and packaging.

The invention features a laminate that includes the cured reactive hot melt adhesive composition disclosed herein, a first substrate, and a second substrate adhered to the first substrate through the cured adhesive composition. The laminate can be a multi-layer textile. The reactive hot melt adhesive composition can be applied using any suitable application method including, e.g., manual or automatic fine line dispensing, slot die coating, roll coating, gravure coating, transfer coating, pattern coating, dot coating, screen printing, spray coating, filament coating, extrusion, air knife, trailing blade, dipping, doctor blade, offset gravure coating, rotogravure coating, and combinations thereof. The reactive hot melt adhesive composition can be in a variety of forms including, e.g., in the form of continuous and discontinuous (e.g., pattern) coatings, beads, layers and films, and each form can include a single layer or multiple layers.

The reactive hot melt adhesive composition can be applied at any suitable temperature including, e.g., from 80°C to 130°C, or even from 100 °C to 130 °C.

The surface of the substrate, on which the reactive hot melt adhesive composition is applied, optionally is treated to enhance adhesion using any suitable method for enhancing adhesion to the substrate surface including, e.g., corona treatments, chemical treatments, flame treatments, and combinations thereof.

The invention will now be described by way of the following examples. All parts, ratios, percentages and amounts stated in the Examples are by weight unless otherwise specified.

EXAMPLES

Test Procedures

The procedures are conducted at room temperature (i.e., an ambient temperature of from about 20 °C to about 25 °C) unless otherwise specified.

Viscosity Test Method

Viscosity is measured on a molten sample that is at the stated temperature using a Brookfield Thermosel Viscometer using a number 27 spindle at 10 rotations per minute, except for Control 2 and Example 3 at 107.2°C which was at 5 rotations per minute.

Sustainable Component Content

The entire percentage of each component that includes at least 25% by weight sustainable content, is counted toward the sustainable component content. As an illustration, Example 1, contains 4.74% HOOPOL F-39037 (38% recycled content) and 75.95% BIO-HOOPOL 11034 (64.2% bio-based carbon content). Example 1 therefore has a sustainable component content of 4.74 + 75.95 = 80.7%.

Hydrolysis Resistance

Hydrolysis resistance is determined according to the following test method. A film is prepared by forming the composition to be tested into a 0.508 millimeters (mm) (20 mil) thick film on release paper. The film is allowed to cure for fourteen days at 25 °C and 50 % relative humidity. Type IV dogbone samples are cut from the film. The initial tensile strength of a set of five samples is measured (Ti). Then samples are soaked in 150 °F (65 °C) deionized water. After a soaking period of 7 and 14 days, a set of five samples is removed from the water and dried. The tensile strength of the dried samples is then measured (Tf) using an Instron testing machine at a cross heat speed of 25.4 centimeters (cm) (10 inches (in)/minute). The result is reported in pounds per square inch (psi) and KPa.

Open Time

Place a can of the adhesive to be tested and a metal draw down square into a convection oven at 121°C (250°F) and allow to equilibrate. Secure a 0.051 millimeter (0.002 inch) thick PET film from Tekra LLC (New Berlin, WI) to the counter with a piece of masking tape and use the pre-heated metal draw down square to apply a 10.2 cm (4 inch) wide film that is .508 millimeters (20 mils) thick. Immediately start a timer. Press 10.2 cm (4 inch) by 1.27 centimeter (0.5 inch) strips of Kraft paper (basis weight 75 gsm (50 lb)), 100% recycled) on the adhesive, starting at the top of the film with the length of the strip across the width of the film, using firm thumb pressure, every 15 seconds until the adhesive is set and the strips no longer stick. Pull the Kraft paper strips off the adhesive and note the amount of fiber tear.

The open time is reported as the last time at which greater than 80% of the width of the adhesive layer bonds the Kraft paper to the film sufficiently to cause it to tear.

Examples

The reactive hot melt adhesive compositions were prepared by combining all of the components set forth in Table 1 except the diisocyanate, in the amounts set forth in Table 1. The mixture was then heated to 110°C until all of the components were melted. A vacuum was then applied and mixing was started and mixing was continued for one hour under vacuum. After one hour, the vacuum was released with nitrogen and the diisocyanate monomer was added to the mixture. The mixture was allowed to react for one hour while the temperature was maintained below 125 °C under vacuum with mixing.

Table One

The inventors found that Example 1 performed in a similar manner as compared to a control composition (not listed) that included only petrol-polyols in peel testing to common textile substrates and further in wash resistance testing of those bonds.

The inventors found that Examples 2 and 3 had acceptable viscosities, similar open times, higher initial strengths and acceptable Hydrolysis Resistance as compared to the petrol based versions (Control 1 and Control 2).

Other embodiments are within the claims.

What is claimed is:

Claims

A reactive hot melt adhesive composition derived from: a. diisocyanate, b. from 20% by weight to 85% by weight of a bio-based polyol, and c. from 1% by weight to 60% by weight of a recycled polyol. The reactive hot melt adhesive of claim 1 derived from 3% by weight to 60% by weight of the recycled polyol. The reactive hot melt adhesive composition of claim 1 wherein the total of a., b. and c. comprises from 90% by weight to 100% by weight of the reactive hot melt adhesive composition. The reactive hot melt adhesive composition of claim 1 derived solely from sustainable polyols. The reactive hot melt adhesive composition of claim 1 wherein the sustainable component content is from 75% by weight to 100% by weight. The reactive hot melt adhesive composition of claim 1 having a monomeric diisocyanate content of less than 0.1% by weight. The reactive hot melt adhesive composition of claim 1 wherein the bio-based polyol is a polyester derived from a material selected from the group consisting of millet, corn, castor oil, sugar and wheat. The reactive hot melt adhesive composition of claim 1 wherein the bio-based polyol comprises an amorphous polyol and a crystalline polyol. The reactive hot melt adhesive composition of claim 1 wherein the bio-based polyol has a bio-based carbon content according to ASTM 6866-20 of from 60% to 100% based on the total carbon content. The reactive hot melt adhesive composition of claim 1 wherein the recycled polyol is derived from recycled polyethylene terephthalate. The reactive hot melt adhesive composition of claim 1 wherein the diisocyanate is sustainable through a bio-mass balance method. The reactive hot melt adhesive composition of claim 1 further comprising a thermoplastic polymer selected from the group consisting of polyester and polyurethane. A laminate comprising: the cured reactive hot melt adhesive composition of claim 1; a first substrate; and a second substrate adhered to the first substrate through the cured adhesive composition. The laminate of claim 13 wherein at least one of the first substrate and the second substrate are selected from the group consisting of recycled materials and bio-based materials. A reactive hot melt adhesive composition comprising: a. from 80% by weight to 100% by weight of a polyurethane prepolymer comprising the reaction product of: i. diisocyanate, ii. a bio-based polyol, and iii. a recycled polyol, wherein the polyurethane prepolymer is derived solely from sustainable polyols.