阅读说明：本技术 具有抗热性改进的水媒性干燥层压粘结剂 (Waterborne dry lamination adhesive with improved heat resistance ) 是由 陈迈 潘元佳 王新宏 陈高兵 刘新春 于 2017-04-11 设计创作，主要内容包括：本公开涉及二组分粘结剂组合物,和用于将所述粘结剂组合物的层施加到衬底层以制造层压物的方法。(The present disclosure relates to two-component adhesive compositions, and methods for applying layers of the adhesive compositions to substrate layers to make laminates.)

1. A two-component binder composition comprising:

(a) a first component which is an aqueous mixture wherein the solids portion thereof comprises (i) from 0.1% to 10% of a polyol containing at least two hydroxyl groups and selected from the group consisting of: water dispersible polyether polyols, polyester polyols, polyether polyester polyols and mixtures thereof, (ii) 3% to 32% rosin resins and (iii) 58% to 96% of a polymer having 20-60% residues of at least one styrene monomer, 40-80% residues of at least one acrylic monomer having a Tg of less than 0 ℃, 1-4% (meth) acrylic acid residues and less than 0.5% residues of hydroxyl containing monomers; and

(b) a second component comprising a water-dispersible polyisocyanate,

wherein the second component is present in an NCO/NCO-reactive group molar ratio of 1:1 to 8:1 relative to the first component.

2. The composition of claim 1, wherein the weight average molecular weight of the polymer is between 5,000 and 2,000,000.

3. The composition of claim 1, wherein the polyol is polypropylene glycol.

4. The composition of claim 1, wherein the polyol has a number average molecular weight of from 100 to 7,500.

5. The composition of claim 1, wherein the rosin resin is selected from the group consisting of modified rosin, hydrogenated rosin, disproportionated rosin, and polymerized rosin, each obtained by modifying, hydrogenating, disproportionating, and polymerizing a starting rosin; and rosin esters, which are obtained by esterifying a raw material rosin with an alcohol or an epoxy compound.

6. The composition of claim 5, wherein the modified rosin resin is selected from unsaturated modified rosins obtained by modifying a starting rosin with an unsaturated acid; and a phenol-modified rosin obtained by modifying a raw material rosin with a phenol.

7. The composition of claim 6, wherein the unsaturated acid is acrylic acid, methacrylic acid, fumaric acid, and maleic acid.

8. The composition of claim 6, wherein the phenols are phenol and alkylphenol.

9. The composition of claim 5, wherein the alcohol is glycerol.

10. The composition of claim 5, wherein the alcohol is pentaerythritol.

11. The composition of claim 1, wherein the rosin resin has a molecular weight of 1,000 to 50,000.

12. The composition of claim 1, wherein the rosin resin has an acid value of 1 to 50KOH mg/g.

13. The composition of claim 1, wherein the rosin resin has a softening point from 25 ℃ to 200 ℃.

14. The composition of claim 1, wherein the polyisocyanate is selected from polyisocyanates based on: toluene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, isomers thereof, and mixtures thereof.

15. A method for making a laminate in which at least two substrate layers are bonded together by a layer of adhesive, the method comprising bonding the at least two substrate layers by the adhesive composition of claim 1.

16. A laminate of at least two substrate layers bonded by the adhesive composition of claim 1.

Technical Field

The present disclosure relates to a two-component acrylic-urethane binder employing an aqueous acrylate/urethane hybrid composition. The present disclosure is particularly suitable for use as a laminating adhesive and for use in, for example, laminating flexible films, aluminum foil, and other substrates.

Background

Solvent-based polyurethanes have been widely used as laminating adhesives to obtain good heat and moisture resistance. In recent years, it has been desirable to expand the selection of commercially available binders (including, for example, adhesives and primers) to meet the increasing number of new technology applications. The desire to reduce chemical solvent emissions and improve ease of handling drives the need for improved waterborne binder systems. One such system that has become popular in a wide range of applications is the latex system; i.e., aqueous dispersions or emulsions. Particularly attractive are acrylic latex systems.

However, limited by their heat resistance, current water-based adhesives are hardly able to meet the requirements of medium performance high-demand packaging (such as zipper inserts and stand-up pouches).

It is desirable to provide waterborne adhesives with improved heat resistance.

Disclosure of Invention

The present disclosure relates to a two-component binder composition comprising: (a) a first component which is an aqueous mixture, the solid portion of which comprises: (i) 0.1% to 10% of a polyol containing at least two hydroxyl groups and selected from the group consisting of: water dispersible polyether polyols, polyester polyols, polyether polyester polyols and mixtures thereof, (ii) 3% to 32% rosin resins and (iii) 58% to 96% of a polymer having 20-60% residues of at least one styrene monomer, 40-80% residues of at least one acrylic monomer having a Tg of less than 0 ℃, 1-4% (meth) acrylic acid residues and less than 0.5% residues of hydroxyl containing monomers; and (b) a second component comprising a water-dispersible polyisocyanate; wherein the second component is present in an NCO/NCO-reactive group molar ratio of 1:1 to 8:1 relative to the first component. The present disclosure further relates to a method for producing a coating on a substrate. The method includes applying a layer of an adhesive composition.

Detailed Description

The disclosed compositions and methods allow for the lamination of two or more flexible or rigid substrates. The present disclosure relates to two-component, aqueous binder compositions that are hydrophobic and contain residues of aromatic monomers. Some of the first includes rosin resin, and a copolymer of a styrene-type monomer, a hydrophobic acrylic monomer, and a carboxyl-functional acrylic monomer. In some embodiments, the content of the hydroxyl functional acrylic monomer is very limited in this disclosure. A water-dispersible or water-soluble polyol is blended into a part one to provide hydroxyl groups for crosslinking with a part two, the part two comprising a water-dispersible polyisocyanate.

The two parts are mixed prior to contacting the surfaces (e.g., as applied to a laminating machine). The adhesive is applied to one substrate and preferably dried through an oven before the other layer of the substrate is applied. The laminate may then be cured, for example at ambient temperature. The polyol in the latex is preferably cured with a polyisocyanate to form a hybrid system of acrylic copolymer and urethane. The copolymer helps to obtain the desired heat resistance and moisture resistance at high temperatures.

The resulting binder exhibits excellent heat, chemical and environmental resistance, as well as adhesion over a wide range of temperatures (e.g., preferably at least-10 ℃ to +120 ℃) and humidity. The binder preferably has a pot life after more than 8 hours of mixing and is easy to handle and apply. In some embodiments, the adhesive is in contact with the first substrate and the second substrate is also in contact with the adhesive to form a laminate. The binder has excellent mechanical stability at high speeds.

All percentages mentioned herein are by weight and temperatures are in units of ° c, unless otherwise specified. As used herein, a "binder" is an agent suitable for bonding to at least a first material itself, and preferably also to a second material. The first and second materials may be the same or different. Multiple layers of material may be bonded using an adhesive. "adhesive" encompasses adhesives, primers, or any other suitable coating for bonding to a surface. As used herein, the term "(meth) acrylate" refers to either an acrylate or a methacrylate. "latex" or "latex composition" refers to a dispersion of a water-insoluble polymer that can be prepared by conventional polymerization techniques, such as by emulsion polymerization. The term "acrylic monomer" means Acrylonitrile (AN); acrylamide (AM) and N-substituted derivatives thereof; acrylic Acid (AA), methacrylic acid (MAA) and esters thereof; and Itaconate (IA). Esters of AA and MAA include, but are not limited to, Methyl Methacrylate (MMA), Ethyl Methacrylate (EMA), Butyl Methacrylate (BMA), ethylhexyl methacrylate (EHMA), dodecyl methacrylate (LMA), hydroxyethyl methacrylate (HEMA), Methyl Acrylate (MA), Ethyl Acrylate (EA), Butyl Acrylate (BA), isobutyl acrylate (IBA), ethylhexyl acrylate (EHA), and hydroxyethyl acrylate (HEA), as well as other esters of AA or MAA. The term "styrene monomer" means an ethylenically unsaturated monomer substituted with aromatic groups, preferably styrene (Sty) and substituted styrenes such as alpha-methyl styrene (AMS).

The aqueous mixture of the first component of the present disclosure is preferably a latex, which is a water-based dispersion of polymer particles of ethylenically unsaturated monomers. The polymer is provided in an amount of 58-96% of the solids portion of the first component. In some embodiments, the amount of polymer is no more than 95%, or no more than 93%, or no more than 92%, or no more than 90%. In some embodiments, the amount of polymer is at least 56%, or at least 65%, or at least 70%. In addition to acrylic and styrene monomers, suitable monomers can include, for example, vinyl groups (e.g., acetates, such as vinyl acetate, ethylene vinyl acetate; alcohols; chlorides, such as polyvinyl dichloride, polyvinyl chloride; and the like). The latex will typically exhibit a viscosity in the range of about 10 to 1000cps, and more preferably 20 to 500 cps. The solids content of the latex may be in the range of 5 to 95%. In some embodiments, it is in the range of 20 to 80%, or 30 to 70%, or 40 to 60%. In some embodiments, the latex polymer has a weight average molecular weight between 5000 and 2,000,000 or between 100,000 and 2,000,000.

In some embodiments, the polymer has 20-60%, or no more than 50%, residues of at least one styrene monomer. In one embodiment of the present disclosure the polymer has 23-45% residues of at least one styrene monomer, preferably styrene residues. The polymer is derived from 40-80% of residues of at least one acrylic monomer having a Tg of less than 0 ℃. In some embodiments, the polymer has 50-80% of at least one C₄-C₁₂Residues of alkyl acrylate monomers. In some embodiments, C₄-C₁₂The alkyl acrylate monomer is BA, EHA, IBA, LMA or a combination thereof.

In some embodiments, the polymer has 1-4% (meth) acrylic acid residues. In some embodiments, the polymer has 1-3%, and most preferably 1.5-2.5% (meth) acrylic acid residues. In some embodiments, the (meth) acrylic acid residue in the polymer is an acrylic acid residue.

In some embodiments, the polymer has less than 0.5% residues of hydroxyl-containing monomers. In some embodiments, the polymer has less than 0.3%, or less than 0.2% of such residues, or the polymer is substantially free of residues of hydroxyl-containing monomers. Examples of hydroxyl-containing monomers include, for example, HEMA, HEA, vinyl alcohol, hydroxypropyl methacrylate (HPMA), and hydroxypropyl acrylate. In some embodiments, the polymer is substantially free of amino group-containing monomers. In some embodiments, the polymer has less than 0.5%, or less than 0.2%, isocyanate-reactive groups other than carboxylic acid groups, or the polymer is substantially free of isocyanate-reactive groups other than carboxylic acid groups.

It will be appreciated that surfactants may be employed in the binders of the compositions of the present disclosure as desired (e.g., for emulsion or dispersion polymerization) to provide stability, as well as control particle size. Conventional surfactants comprise anionic or nonionic emulsifiers or combinations thereof. Typical anionic emulsifiers include, but are not limited to, alkali alkyl or ammonium alkyl sulfates, alkali alkyl or ammonium alkyl ether sulfates, alkali alkylaryl or ammonium alkylaryl ether sulfates, alkyl sulfonates, salts of fatty acids, esters of sulfonated succinates, alkyl diphenyl ether disulfonates, and salts of complex organophosphates or free acids. Typical nonionic emulsifiers include, but are not limited to: polyethers, such as ethylene oxide and propylene oxide condensates, containing straight and branched chain alkyl and alkylaryl polyethylene and polypropylene glycol ethers and thioethers; an alkylphenoxypoly (ethyleneoxy) ethanol having an alkyl group containing from about 7 to about 18 carbon atoms and having from about 4 to about 100 ethyleneoxy units; and polyoxyalkylene derivatives of hexitols comprising sorbitan, mannose esters and mannide. Surfactants may be employed in the polymer compositions of the present disclosure at levels of 0.1 to 3 wt.% or more, based on the total weight of the polymer composition.

The polymer composition is mixed with a water dispersible polyol to provide hydroxyl functionality. Water dispersible polyols are polyols that will form a solution or emulsion in water at any content in the range of 1-50% at room temperature with stirring. In some embodiments, the polyol may be a polyether polyol, a polyester polyether polyol, or mixtures thereof. The polyol will have a polyhydroxy functionality and thus will contain at least two hydroxyl groups. Preferred polyols are selected from diols, triols or mixtures thereof. The polyol is sufficiently nonvolatile that it will be fully or at least partially available for reaction with the isocyanate during the mixing operation. The polyols are also water soluble or water dispersible. In some embodiments, the number average molecular weight of the polyol is from 100 to 7,500, or from 150 to 5,000, or from 200 to 1,000. In some embodiments, the molecular weight is less than 1500, or less than 600. In some embodiments, the polyol is a polypropylene glycol (PPG), such as 400MW polypropylene glycol. In some embodiments, the polyol is provided in an amount of 0.1 to 10% of the solids portion of the first component. In some embodiments, the amount of polyol is no more than 5%, or no more than 3%, or no more than 2%, or no more than 1.5%. In some embodiments, the amount of polyol is at least 0.3%, in some embodiments at least 0.4%, or at least 0.6%. The solid portion of the composition is a non-volatile portion, typically including polymers and other non-volatile additives, such as surfactants, pigments, flame retardants; and does not include water and other solvents.

The polymer latex was further mixed with a rosin resin. The rosin resin can be present in solid or water-dispersible form. Water dispersible rosin resins are rosin resins that will form a solution or emulsion in water at any content in the range of 1-60% at room temperature with stirring. The rosin resins used in the present disclosure are processed from raw rosin (such as rosin, high oil rosin and wood rosin) by at least one of the following methods: a) modification, b) hydrogenation or disproportionation and c) polymerization or esterification. In the case where the rosin resin is processed by at least two of the above methods, the processing order of the methods b) and c) is not particularly limited, and only the polymerization method must follow (not necessarily directly after) the modification method (if both of them are used). Suitable examples of the rosin resin include modified rosin, hydrogenated rosin, disproportionated rosin, and polymerized rosin, which are respectively obtained by modifying, hydrogenating, disproportionating, and polymerizing a raw rosin; and further pine esters obtained by esterifying a raw material rosin with an alcohol or an epoxy compound. Suitable examples of the modified rosin include an unsaturated modified rosin obtained by modifying a raw rosin with an unsaturated acid, and a phenol-modified rosin obtained by modifying a raw rosin with a phenol. Suitable examples of unsaturated acids include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Suitable examples of phenols include phenol and alkyl phenols. The modification method is not particularly limited and the following methods are generally adopted: the raw material rosin is mixed with a phenol or an unsaturated acid and heated.

Suitable examples of alcohols for use in the preparation of pine esters from starting materials rosin and alcohols include monovalent alcohols such as methanol, ethanol, and propanol; divalent alcohols such as ethylene glycol, diethylene glycol, propylene glycol and neopentyl glycol; trivalent alcohols such as glycerin, trimethylolethane, and trimethylolpropane; tetravalent alcohols such as pentaerythritol and diglycerol; and hexavalent alcohols, such as dipentaerythritol. Preferably the alcohol is glycerol, and more preferably the alcohol is pentaerythritol. The esterification method of rosin is not particularly limited, and the following methods are adopted: the starting rosin is mixed with an alcohol and the mixture is heated in the presence of an optional esterification catalyst. Rosin esters prepared from disproportionated rosin (i.e., disproportionated rosin) and rosin prepared from polymerization (i.e., polymerized rosin) are preferred.

The rosin resin is provided in an amount of 3-32% of the solid portion of the first component. In some embodiments, the amount of rosin resin is no more than 30%, or no more than 28%, or no more than 25%, or no more than 20%. In some embodiments, the amount of rosin resin is at least 3%, or at least 6%, or at least 8%.

The acid value and softening point of rosin resins vary depending on their species. The acid number is typically from 1 to 50KOH mg/g, or from 1 to 15KOH mg/g and the softening point is from 25 ℃ to 200 ℃, or from 60 ℃ to 190 ℃.

In some embodiments, the rosin resin has a molecular weight of 1,000 to 50,000, preferably 2,000 to 10,000.

Other tackifier resins can be used in place of the disclosed rosin resins and similar performance is obtained. Suitable examples of other tackifier resins include terpenes and modified terpenoid resins; an aliphatic resin; cycloaliphatic and aromatic resins, e.g. C₅Aliphatic resin, C₉Aromatic resin and C₅/C₉Aliphatic/aromatic resins; a hydrogenated hydrocarbon resin; a terpene-phenol resin; and any combination thereof.

Optionally, conventional ionic or nonionic surfactants can be used to prepare the rosin resin. In some embodiments, the surfactant is an anionic surfactant, and suitable examples of anionic surfactants are selected from the group consisting of sulfonates, phosphates, carboxylates, and any combination thereof. In some embodiments, the anionic surfactant is a sulfonate (e.g., alkyl monoester sulfosuccinate) and a phosphate (e.g., polyoxyethylene nonylphenyl ether branched phosphate).

In some embodiments, in the preparation of the rosin resin, the rosin resin is substantially free of organic solvent, i.e., it contains less than 3%, or less than 2%, or less than 1%, or less than 0.5 or less than 0.2%, or less than 0.1% by weight of organic solvent based on the total weight of the rosin resin. Solvents that may be present in the rosin resins of the present disclosure within the limits set forth are hydrocarbon-based solvents, preferably aromatic solvents and more preferably toluene.

The polyisocyanate is the second component of the present disclosure, which is any suitable polyisocyanate. In some embodiments, the polyisocyanate is an aliphatic polyisocyanate, an aromatic polyisocyanate, or a mixture thereof. In some embodiments, the polyisocyanate is a diisocyanate. Suitable examples of polyisocyanates include those based on Toluene Diisocyanate (TDI), isophorone diisocyanate (IPDI), Hexamethylene Diisocyanate (HDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), isomers thereof, or mixtures thereof. Prepolymers of polyisocyanates with polyols may also be used. Aliphatic polyisocyanates are preferred. The polyisocyanate is water soluble or dispersible, i.e. it will form a solution or emulsion in water at any level in the range of 1-50% at room temperature with stirring.

The polyisocyanate is present in the binder in a percentage of 1 to 5% by weight based on the total weight of the first component.

The relative proportions of isocyanate groups to isocyanate-reactive groups may vary as desired within a molar ratio of NCO/NCO-reactive groups of from 1:1 to 8: 1. NCO reactive groups include, for example, hydroxyl, amino, and carboxyl groups. In some embodiments, the NCO/NCO-reactive group molar ratio is at least 3: 1. In some embodiments, the NCO/NCO-reactive group molar ratio does not exceed 5: 1. In some embodiments, the polyisocyanate is provided in an amount of up to 0.01 to 0.8 (and more preferably 0.1 to 0.3) parts polyisocyanate to 1 part solids in the latex, with the polyol present in the above preferred ratio relative to the isocyanate groups. The pH of the resulting total mixture is preferably 5 to 9, and more preferably 6 to 8.

Other optional components of the binders of the present disclosure include, but are not limited to, agents selected from the group consisting of: co-solvents, coalescents, pigments or other colorants, fillers, reinforcements (e.g., fibers), dispersants, wetting agents, waxes, catalysts, blowing agents, defoamers, UV absorbers, flame retardants, adhesion promoter antioxidants, biocides, coalescents, or stabilizers. These optional components (as desired) may be added in any order of addition that does not result in incompatibility between the components. Components that are not soluble in the aqueous vehicle, such as pigments and fillers, can be dispersed in the latex or the aqueous vehicle or co-solvent using a mixer, optionally a high shear mixer. The pH of the composition can be adjusted by adding an acid or base under stirring. Examples of bases include, but are not limited to, ammonia, diethylamine, triethylamine, dimethylethanolamine, triethanolamine, sodium hydroxide, potassium hydroxide, and sodium acetate. Examples of acids include, but are not limited to, acetic acid, formic acid, hydrochloric acid, nitric acid, and toluenesulfonic acid.

As inferred from the foregoing, the disclosed system contemplates the use of two components that are preferably mixed using a suitable mixer (e.g., an electrically, pneumatically, or otherwise powered mechanical mixer) to form the binder prior to or during application to the substrate. Thus, the latex/polyol blend is typically packaged separately from the polyisocyanate. The mixing can be performed at any suitable time in the process, such as before, during, or as a result of the application process. All inventive steps may be performed at ambient room temperature conditions. Heating or cooling may be employed as desired.

The adhesives of the present disclosure may be used to bond substrates together. The substrates may be of similar materials or of different materials. Although a wet lamination process is possible, the adhesive is preferably particularly suitable for dry adhesive lamination of a plurality of substrate layers. In one preferred embodiment, a layer of adhesive is applied to a first substrate layer, water is removed (e.g., by hot air or otherwise) and the resulting dried adhesive layer is covered with a second substrate layer to form a laminate in which the two substrates are bonded together by the dried layer of adhesive. In a preferred embodiment, the backing layer is provided in the form of a roll of backing material. The sheet may be about 1 to 10 mils thick. Larger thicknesses are also possible, as are smaller thicknesses (e.g., about 1 or more than 1 micron).

The compositions of the present disclosure can be applied to a desired substrate using conventional application techniques such as rotogravure, flexography, conventional or airless spraying, roll coating, brush coating, wire bar coating, blade coating, or coating processes such as curtain coating, flood coating, ribbon coating, pan coating, and dip coating processes. Coating with the adhesive may be performed over the entire surface or only a portion thereof (e.g., along an edge or at intermittent locations). Once applied to the substrate, the composition is dried, such as by application of heat and air flow or some other suitable method, for removing substantially all remaining water.

The present disclosure benefits from the advantageously long pot life of the binder. Thus, after the components of the binder are mixed, it is expected that hours may be permitted to pass before application to the substrate. For example, in one embodiment, the useful life is at least 8 (and more preferably at least 12-24) hours, and thus at least eight hours may pass before application to the substrate.

The binder composition may be suitable for other applications such as topcoats or other intermediate coatings, thereby making it potentially useful for paints, inks, plastics, and the like. The adhesive compositions of the present disclosure may be used on a wide variety of one or more suitable substrates such as high, low or medium density plastics (e.g., of the type selected from polystyrene, polyethylene, ABS, polyurethane, polyethylene terephthalate, polybutylene terephthalate, polypropylene, polystyrene, polycarbonate, polyacrylate, polyvinyl chloride, polysulfone, or mixtures thereof), paper, wood and reconstituted wood products, polymer coated substrates, wax coated cardboard, particle board, fabric, leather and metal (aluminum, ferrous and other non-ferrous), metalized plastics (e.g., metalized plastic films), and the like. Adhesives are particularly attractive for packaging and sealing applications. For example, in one aspect, a plastic film, a metal film, or a metalized plastic film is laminated with the disclosed adhesive (e.g., on all or at least a portion of its surface, such as along an edge thereof or at a location of a discontinuity). In one such application, the food product is packaged for retort pouch preparation, or the resulting laminate can be used to seal or package some other article.

Examples of the invention

I. Raw material

Film formation: the substrates used in the examples comprised biaxially oriented polypropylene film (BOPP, 18 μm thick), vacuum metallized cast polyethylene terephthalate polyester film (VMPET, 12 μm thick) film and polyethylene film (PE, 60 μm thick) as commercially available from Guangdong Nan Cheng company.

The ingredients used in the examples include those listed in table 1 below.

Table 1: ingredients used in the examples

Test methods

The water-based adhesives and BOPP, VMPET, PE films were used without any pretreatment. The adhesive was added at 2.0g/m²The amount of dry weight was coated to a BOPP film and combined with a VMPET film to obtain a BOPP/VMPET 2 layer laminate and dried. The 2-ply laminate was then adhered with a water-based adhesive at 2.0g/m²The amount of dry weight was coated and combined with PE film to obtain a BOPP/VMPET/PE 3 layer laminate. The BOPP/VMPET/PE 3 layer laminate was cured at 50 ℃ for 2 days and then tested.

i) Bond Strength (BS):

the laminates of the present disclosure were cut into 25mm wide by 10cm long strips using a metal template for the T-peel test using a 5943 series single column bench top system available from Instron Corporation (Instron Corporation) at a 250mm/min crosshead speed. During testing, the tail of each strip was pulled slightly by a finger to ensure that the tail remained 90 degrees from the peel direction. Three strips of each sample were tested and the average calculated. The results are in units of N/15 mm. The higher the value, the better the bond strength.

ii) Heat seal Strength (HS)

The laminate was heat sealed in an HSG-C heat sealer available from Brugger Corporation at 140 ℃ sealing temperature and 300N pressure for 1 second (or 0.5 second at 220 ℃ sealing temperature and 300N pressure), then cooled, and cut into 25mm wide by 10cm long strips using a 5943 series single column bench top system available from Instron Corporation at 250mm/min crosshead speed for heat seal strength testing. Three strips of each sample were tested and the average calculated. The results are in units of N/15 mm. The higher the value, the better the heat seal strength.

Example iii:

470.25g of an acrylic copolymer emulsion (BA-styrene copolymer with 44% solids) were placed in a 1 liter bottle with an electromagnetic stirrer, followed by 4.75g of a polyol (polyether diol) and 25g of SUPER ESTER^TME-865NT rosin resin was poured into the bottle and stirred for 20 minutes. When the mixed composition was dispersed, 10g of COREACTANT CR 3A polyisocyanate was added dropwise to the mixture emulsion and the mixture was stirred for an additional 20 minutes.

Exemplary adhesive examples IE1, IE2, IE3 and IE4, and comparative adhesive examples CE1, CE2 and CE3 were prepared from the ingredients listed in table 1. The same mixing process as described above was repeated for each example, but utilizing the ingredients according to the compositions listed in table 2.

Table 2: example compositions

CE1

IE1

IE2

IE3

IE4

CE2

CE3

BA-styrene copolymer

98％

88.2％

78.4％

94％

68.6％

88.2％

88.2％

Polyether diol

2％

1.8％

1.6％

1％

1.4％

1.8％

1.8％

SUPER ESTERTM E-865NT

-

10％

20％

5％

30％

-

-

HORDAMERTM PE35

-

-

-

-

-

10％

-

AQUACERTM 593

-

-

-

-

-

-

10％

COREACTANT CR 3A*

2％

2％

2％

2％

2％

2％

2％

Based on the total weight of component A%

Exemplary adhesive examples IE1, IE2, and comparative adhesive example CE1 were each coated onto VMPET and PE60 films to obtain VMPET/PE 602 layer laminates for further testing.

Exemplary adhesive examples IE1, IE2, IE3 and IE4, and comparative adhesive examples CE1, CE2 and CE3 were each coated onto BOPP, VMPET and PE60 films to obtain BOPP/VMPET/PE60 laminates for further testing.

Results IV

As shown in table 3, the illustrative adhesive examples IE1 and IE2 significantly improved the chassis seal strength at 140 and 220 ℃ compared to comparative adhesive example 1.

Table 3: performance results

As shown in table 4, the exemplary adhesive examples IE1, IE2, IE3, and IE4 significantly improved heat seal strength at 220 ℃ compared to those of the comparative adhesive examples CE1, CE2, and CE 3.

Table 4: performance results