Hot melt adhesives containing an additive derived from epoxy reactive hydrogen containing polymers and compounds and a polyepoxy compound

The adhesive properties of a hot melt adhesive, comprising a base polymer and a tackifying resin, can be improved by introducing into the hot melt adhesive an epoxy adduct comprising the reaction product between a compound such as a polymer having at least one active hydrogen and an epoxy compound.

FIELD OF THE INVENTION 
The invention relates to a hot melt adhesive composition and to a novel 
additive for hot melt adhesive compositions which can be blended into an 
adhesive to increase or improve its adherent or other properties. 
Typically a hot melt adhesive comprises a blend of a thermoplastic base 
polymer and other adhesive additive compositions such as tackifiers, 
extending oils, waxes, inorganic compositions, and other components. These 
components cooperate to provide desirable properties to the adhesive 
composition as a whole. 
More particularly, the invention relates to a novel epoxy adduct 
composition which can be used in conjunction with conventional adhesive 
thermoplastic polymers and additives in the formulation of new hot melt 
adhesives with novel levels or combinations of adherent or other 
properties. 
BACKGROUND OF THE INVENTION 
Hot melt adhesives are adhesives which are applied molten, at elevated 
temperatures in the substantial absence of a solvent. The hot melt can be 
applied in a glue line and can form a strong, adherent bond when cooled. 
Hot melt adhesives are typically made by combining a thermoplastic base 
polymer with a variety of other additive components to produce desirable 
properties in the finished adhesive composition. A great deal of attention 
has been directed for many years to the development and the formulation of 
hot melt adhesives in view of the economy, safety, ease of use, and 
applicability of hot melt adhesive technology. 
Hot melt adhesives can be made from a variety of thermoplastic base 
polymers including ethylene-vinyl acetate polymers, atactic polypropylene 
polymers, acrylic polymers, vinyl pyrrolidone polymers, 
polyalkylene-oxazoline polymers, natural and synthetic rubbers such as 
KRATON, KRATON G and others, etc. Such hot melt adhesives can be pressure 
sensitive, and can be used on a variety of natural and synthetic 
substrates. The adhesives can be either insoluble in water or partially or 
fully soluble in water, and can be water actuated. 
The successful formulation of a variety of hot melt adhesives with various 
properties requires a number of multi-functional adhesive components. Many 
adhesive components currently available for use in adhesive formulation 
can be used in combination to provide an adhesive of high quality. Certain 
adhesive applications have no fully successful adhesive. Fluorocarbon 
bonded materials, for example, are well known for resistance to formation 
of strong bonds with current adhesives. New materials in packaging are 
constantly being developed which require adhesives that are useable with 
the new materials. 
A constant search is underway for new adhesive additive compositions for 
use in adhesive formulations that can impart novel properties to 
adhesives, can increase the compatibility of adhesive components, can 
adhere to fluorocarbons and other new materials and can reduce the cost of 
current adhesive formulations. Accordingly a continuing need exists for 
improved hot melt adhesive additive components. 
BRIEF DESCRIPTION OF THE INVENTION 
We have found a novel hot melt adhesive additive composition which can be 
made compatible in common hot melt adhesive formulations and which can 
provide substantially improved adherent and other properties in a number 
of applications. 
Briefly, the adhesive additive composition of this invention comprises an 
epoxy adduct comprising the reaction product of (1) a compound with at 
least one pendent epoxy reactive-active hydrogen, and (2) an epoxy 
compound having preferably two or more free reactive epoxy or oxirane 
rings. Either the reactive hydrogen containing compound or the epoxy 
compound can be polyfunctional to obtain a compatible composition that can 
augment adhesive properties in hot melt compositions. 
Preferably the adhesive additive composition of the invention comprises a 
polymeric adduct comprising the reaction product of (1) a polymer with at 
least one epoxy reactive hydrogen, and (2) an epoxy compound preferably 
with two or more epoxy groups. Alternatively the preferred adhesive adduct 
can contain additionally a monomeric epoxy reactive compound which can 
contain one or more hydroxy groups such as an alkanol amine, or the adduct 
can contain a functional compound such as a dimer acid, a diphenolic 
compound, a diamine or other compound. 
For the purposes of this invention the term polyfunctional means that the 
compound contains two or more of the named functional group. For example, 
a polyfunctional epoxy compound has two or more reactive epoxy or oxirane 
groups in the molecule. Further, the term compatible or compatibility 
means that a composition containing two or more components that differ, 
will not readily separate into phases when held in a melt condition for an 
extended period. 
A first aspect of the invention is the novel hot melt adhesive additive 
composition comprising the epoxy adduct. 
A second aspect of the invention is an epoxypolymeric adduct which is a 
reaction product of a polymer, and an epoxy compound. 
A third aspect of the invention is the adduct of this invention further 
reacted with a monomeric compound with an epoxy reactive hydrogen, or a 
difunctional compound. 
A fourth aspect of the invention is a hot melt adhesive composition 
comprising a base thermoplastic polymer, the novel epoxy adduct additive 
composition of the invention, a tackifying resin, and optionally other 
adhesive additives. 
While we do not wish to be held to a theory of action of the invention, we 
believe that the polyfunctional epoxy adduct can be made with varying 
proportions of components. The reaction product molecular weight, 
hydrophilicity, solubility and size is controlled by the proportions of 
the components and their functionality. In this way polymeric additives 
with acceptable molecular weight, hot melt compatibility and acceptable 
viscosity in the hot melt can be made. 
DETAILED DISCUSSION OF THE INVENTION 
The novel adhesive additive composition of the invention comprises the 
polymeric reaction product of (1) a compound having at least one pendent, 
epoxy reactive group, and (2) a polyfunctional epoxy compound with at 
least two reactive epoxy or oxirane rings. Preferably, the above reaction 
product can contain a dimer compound or a compound having at least one 
epoxy reactive hydrogen, which can have hydroxy functionality, or mixtures 
thereof. 
Compounds that can be reacted with the epoxy compound in forming the epoxy 
adduct of this invention include compositions having a free hydrogen that 
is reactive with an epoxy group. Typically reactive hydrogens are found in 
carboxylic acid groups, aromatic hydroxyl groups, amino groups, and 
sulfhydryl groups. Typically compounds having one of these functional 
groups can be used in forming the epoxy adducts of the invention. 
Typical examples of carboxylic acid compounds that can be used in making 
the adduct of the invention include mono, di and tricarboxylic acids. 
Typically the carboxylic acid compounds have a molecular weight of at 
least 100 to provide some hydrophobic functionality. Carboxylic acids that 
can be used in the invention include benzoic acid, maleic acid, maleic 
anhydride, fumeric acid, and others. Preferred carboxylic acids for use in 
the invention comprise C.sub.6 and higher carboxylic acid including 
unsaturated and polyunsaturated carboxylic acid and their dimer product. 
Most preferred carboxylic acid compounds comprise dimer and trimer acids 
formed by reacting unsaturated groups in the carbon chain of di and 
triunsaturated C.sub.6-24 carboxylic acids. 
Polymers useful in preparing the novel adhesive additive composition of the 
invention can be any polymer having a pendent active hydrogen containing 
group. Such pendent groups include a carboxyl group, an amine group, an 
aromatic hydroxyl, a mercapto group, and others. Useful polymers include 
vinyl polymers, polyesters, polyamides, polycarbonate, carboxylated 
polymers, etc. The polymer chain must contain at least one active hydogen 
containing group as a result of (1) the inclusion of at least one monomer, 
in the polymerization reaction mass, that has a free active hydrogen or 
(2) the formation of an active hydrogen after polymerization by oxidation, 
sulfurization, carboxylation, or other post polymerization reaction. 
Monomers that can be used in the formation of polymers having pendent 
groups having active hydrogens include monomers with pendent carboxyl, 
amine, or aromatic hydroxyl groups. Vinyl monomers containing pendent 
amino groups include acrylamide, methacrylamide, maleimide, 
aminoethylacrylate, aminoethylmethacrylate, n-vinyl heterocyclic monomers, 
and others. Aromatic hydroxyl containing vinyl monomers include hydroxy 
styrene, 5-hydroxy-l-vinyl naphthalene, hydroxy phenyl methacrylate, and 
others. 
Preferred polymers for use in the invention can comprise carboxylated vinyl 
polymers or vinyl polymers having randomly polymerized vinyl monomers with 
one or more free reactive carboxyl groups. Such carboxyl containing vinyl 
monomers must contain at least one polymerizable ethylenically unsaturated 
group and at least one carboxylic acid group which remains free and 
reactive after polymerization. Specific examples of polymerizable 
ethylenically unsaturated carboxylic acid monomer compounds include 
acrylic acid, methacrylic acid, itaconic acid, fumeric acid, maleic acid, 
maleic anhydride (post-polymerization hydrolysis required), crotonic acid, 
4-vinyl benzoic acid, and other aliphatic, aromatic, cyclic, and bicyclic 
carboxylic acid containing monomers, etc. Preferred vinyl monomers 
comprise acrylic acid and methacrylic acid for reasons of economy, 
availability, ease of polymerization and reactivity of the resulting 
carboxyl-containing polymer. 
Alternatively, a polymer can be carboxylated during or after polymerization 
to form pendent carboxyl groups. For example, polyester polymers can be 
formed from a mixture of di- and trifunctional carboxylic acid compounds 
and polyfunctional alcohols resulting in the formation of a polymer with 
pendent reactive carboxyl, also known as carboxylic acid, groups. 
Similarly, polyamide polymers can be made with a mixture of di- and 
trifunctional acids resulting in pendent carboxyl groups. Such polymers 
are well known and the preparation of such polymers are well within the 
skill of the art. Further, polymers and copolymers made of many monomers 
can be oxidized or reacted with a carboxylating agent in known techniques 
to form known polymers with free carboxyl groups. 
The vinyl polymer can be made up of other ethylenically unsaturated 
monomers to insure compatibility between the adhesive additive composition 
and the base thermoplastic polymer of the hot melt adhesive composition. 
In the instance that a polyethyloxazoline base polymer is used we have 
found that an acrylic acid containing vinyl polymer can be used. In the 
instance that a KRATON G (styrene-ethylene butylene-styrene) copolymer be 
used, preferred monomers for use in preparing the vinyl polymer can be 
styrene or other aromatic monomer or a conjugated diene or mixtures 
thereof. In the instance that the hot melt adhesive composition is 
prepared with an ethylene-vinyl acetate base polymer, an ethylene or other 
olefin, a vinyl acetate or other vinyl ester monomer or an ethylene-vinyl 
acetate mixture with the carboxylic acid containing monomer can be made. 
Suitable examples of such vinyl monomers for use in preparing the carboxyl 
containing polymer include ethylene, propylene, styrene, vinyl chloride, 
1,4-butadiene, hydroxyalkyl-acrylate and methacrylate, N-vinyl 
heterocyclic monomers such as N-vinyl pyrrolidone, N-vinyl pyrridine, and 
N-vinyl epsilon-caprolactam; acrylamide, methacrylamide, and 
N-(1,1-dimethyl-3-oxobutyl) acrylamide; the linear or branched C.sub.1-10 
alkyl esters of acrylic acid or methacrylic acid including methylacrylate, 
ethylacrylate, butylacrylate, 2-ethylhexylacrylate, methyl methacrylate, 
ethylmethacrylate, 2-ethoxyethylmethacrylate, cyclohexylmethacrylate, and 
vinyl esters of carboxylic acids including vinyl acetate, vinyl 
propionate, and other vinyl monomers well known in the art. 
Preferred polymers for use in making the adhesive additive composition of 
the invention comprise carboxylated vinyl polymers such as a carboxylated 
styrene butadiene block copolymer or vinyl polymers containing acrylic 
acid or methacrylic acid, having a molecular weight of about 10,000 to 
100,000, a melt index from about 3 to 600, and an acid number from about 
0.2 to 20. The most preferred polymers comprise ethylene-vinyl 
acetate-acrylic or methacrylic acid terpolymers which contain from about 5 
to 95 mole-% ethylene, 5 to 95 mole-% vinyl acetate, and up to about 5 
mole-% of acrylic or methacrylic acid and about 1 to 5 carboxyl groups per 
polymer chain. These carboxylcontaining polymers are available from the 
duPont de Nemours Company, Wilmington, Delaware. 
The polyfunctional epoxy compounds useful in manufacturing the adhesive 
additive compositions of this invention are typically known as epoxy 
resins. Epoxy resins are most commonly made by reacting a glycidyl 
compound with another reactive compound resulting in a polyfunctional 
epoxy compound. Epoxy Novolak resins useful in the invention can have the 
following general formula: 
##STR1## 
wherein p is about 0 to 20 and G is 
##STR2## 
a glycidyl residue. Another useful epoxy resin has the formulae: 
##STR3## 
wherein Y is a group resulting from the reaction product of a 
epihalohydrin such as epichlorohydrin and a polyhydric phenol. Typical 
polyhydric phenols include such compounds as resorcinol and various 
bis-phenols resulting from the condensation of phenol with aldehydes and 
ketones in a well known class of condensation reactions. Representative of 
commercially available compositions include the Novolak compositions and 
glycidyl adducts of bisphenols such as 2,2'-bis(phydroxyphenyl)propane; 
4,4'-dihydroxydiphenylsulfone; 4,4'-dihydroxybiphenyl; 
4,4'-dihydroxydiphenylmethane; 2,2'-dihydroxydiphenyloxide, etc. 
The preferred epoxy resins of the invention comprise a glycidyl adduct of a 
condensation product of formaldehyde and phenol; a glycidyl adduct of a 
bisphenol compound; a diglycidyl ether of a bisphenolunsaturated fatty 
acid dimer reaction product; or a glycidyl adduct of an unsaturated fatty 
acid dimer. Such resins are well known and are commercially available 
under the EPON trademark from Shell Chemical Co. 
Monofunctional compounds having one epoxy reactive hydrogen can be used in 
combination with the carboxylcontaining polymer and the polyfunctional 
epoxy compound to form the polymeric adhesive additive compositions of the 
invention. Active hydrogen atoms are typically found on groups such as 
amines including secondary amino groups; carboxyl groups; phenolic 
hydroxyl groups; and mercaptan (-SH, sulfhydryl) groups. Monofunctional 
epoxy reactive active hydrogen containing compounds include monoacids, 
monophenols, monomercaptans and monoamines. Monoacids include acetic acid, 
butyric acid, heptanoic acid, palmitic acid, olearic acid, benzoic acid, 
oleic acid, abietic acid, etc. Monophenols include phenol, nonylphenol, 
p-tertbutylphenol, etc. Monomercaptans include laurylmercaptan, 
dodecylmercaptan, etc. Monoamines are preferably secondary monoamines 
which include dimethylamine, laurylmethylamine, dibutylamine, 
benzylethylamine, etc. 
We have found in the preparation of the adhesive additive compositions of 
the invention that the polyfunctional epoxy compound tends to react with 
the carboxyl groups in the carboxyl-containing polymer. Such reaction 
tends to produce beta hydroxy linkages and a side chain with a terminal 
epoxy group which further react with carboxyl or other epoxy reactive 
groups. By varying the type and amounts of epoxy and epoxy reactive 
groups, a polymeric adhesive additive composition with varied properties 
can be produced. 
In some cases epoxy reactive active hydrogen containing compounds 
preferably contain hydroxy functionality, and can contain about 1 to 4 
hydroxy groups per molecule. Typical hydroxyl containing amines include 
monoalkanol amines, dialkanol amines, hydroxy substituted piperidine, 
hydroxy substituted cyclohexyl amine, and others. Preferred hydroxyl 
containing amines include the mono and di C.sub.2-5 -alkanol amines. The 
most preferred hydroxyl containing amines comprise the monoethanol amine 
and diethanol amine. 
Hydroxyl containing mercapto or sulfhydryl compounds can include virtually 
any organic compound having both a hydroxyl group and a sulfhydryl group. 
The mercapto group is typically reacted with the epoxy group and the 
polymeric additive composition. Examples of hydroxyl containing mercapto 
compounds include 2-mercaptoethanol, 3,3-mercapto-l,2-hydroxy propane, 
4-mercaptocyclohexanol, 2-hydroxyl-l,3-propanethiol, and others. 
Hydroxy substituted carboxylic acid compounds can be used as a hydroxyl 
compound having a reactive hydrogen group. Examples of hydroxy substituted 
carboxylic acids include lactic acid, trimethylol propionic acid, 
2-hydroxy succinic acid, 4-hydroxy benzoic acid, 5-hydroxy valeric acid, 
12-hydroxy stearic acid, 4-hydroxy phenylacetic acid, and others. 
Polyfunctional hydroxy aromatic compounds can be used as hydroxyl compounds 
with a reactive hydrogen atom in preparing the polymeric adhesive additive 
compositions of the invention. Typically the polyfunctional hydroxy 
aromatic compound contains 2 or more hydroxy compounds substituted on an 
aromatic nucleus. Typical examples of such compounds include catechol, 
resorcinol, hydroquinone, 2,6-hydroxy-naphthalene, and others. 
Optionally, the novel adhesive additive composition of the invention can 
include other components which affect the properties of the additive. One 
preferred optional component comprises a dimer acid composition. We have 
found that the inclusion of dimer acid compositions in the reaction 
product improves the mechanical characteristics of adhesives containing 
the composition. Dimer acid compositions are well known products 
comprising the reaction product of at least two C.sub.12 -C.sub.24 
unsaturated fatty carboxylic acid compounds. Dimer acids are typically 
formed through the reaction of at least one unsaturated site on each 
carboxylic acid molecule which join the molecules into a dimer acid. Such 
dimer acids are well known in the art and sold under the EMPOL trademark. 
Other diacids, diphenols, diamines preferably secondary, dimercaptans and 
monoamines can be used as reactants in the preparation of the epoxy adduct 
of the invention. 
Catalysts may preferably be added to the reaction mixture to shorten the 
reaction time and to control the reaction products. Catalysts that can be 
used are known to those skilled in the art. See for example "Handbook of 
Epoxy Resins" by Lee and Neville, 1967, McGraw-Hill, Inc. Catalysts 
include tertiary amines (like tributylamine, benzyldimethylamine), 
quaternary phosphonium salts, tertiaryphosphines (like 
triphenylphosphine), acid salts (like potassium acetate, lithiumbenzoate, 
lithiumnaphthenate, sodium acetate). 
Since the novel adhesive additive composition of this invention is 
primarily directed for hot melt formulation, the additive composition is 
typically prepared in the absence of solvents. However, solvents can be 
used but their use typically requires a postreaction stripping step to 
remove substantially all solvent traces. Typically the composition is 
prepared in any adequate industrial reaction vessel. Preferred reaction 
vessels include standard heated industrial mixers which can effectively 
contact the viscous reactants under reaction promoting conditions. 
Typically the reaction can be run at sufficiently high temperature to 
reduce the viscosity of the reactants and to promote the reaction between 
the components. Such effective reaction temperature is about 100 to 
400.degree. F., preferably 125 to 375.degree. F., and most preferably 
150-350.degree. F. for reasons of reaction speed, low viscosity, and 
convenience. Typically, the reactants complete the reaction in a period of 
from about 1 to 5 hours, most typically from about 1 to 3 hours. 
Typically, the components are reacted at mole ratios which provide the 
properties desired in the product. The amount of epoxy and epoxy reactive 
hydrogen compound can be varied in order to increase or decrease the 
hydrophilicity of the polymer or the compatibility of the additive with 
water soluble or water actuated components. Other components of the 
reaction product can be varied with compatibility properties in mind. 
Typically the reaction product is made by combining sufficient quantity of 
the carboxylcontaining polymer and about 1 to 50 mole-% of the epoxy 
resin, and from about 0.1 to about 50 mole-% of the monofunctional such as 
hydroxy compound. Optionally the composition can also contain about 1 to 
15 mole-% of a dimer acid composition. 
Within the broad reaction parameters described above, specific adduct 
compositions can be made using proportions of reactants that control 
molecular weight and prevent crosslinking or gel formation. 
Molecular weight control and prevention of gelling is typically controlled 
by the inclusion of sufficient monofunctional reactant in the reaction 
mixture to reduce crosslinking which is typically caused by the reaction 
of di-, tri- or other higher polyfunctional compounds. Polymeric reactants 
can be considered monofunctional if the polymer chain contains on the 
average less than 2 pendent functional groups. Gellation is typically 
reduced since monofunctional compounds can end both polymeric chain growth 
and crosslinking in the typical reaction mixture. More particularly, if a 
polymer with two or more epoxy reactive groups per polymer molecule is 
included in the formulation in the reaction mixture can include a high 
percentage of monofunctional epoxy or other active hydrogen compounds. 
Molecular weight control can also be obtained using molar excesses of a 
reactant such as a molar excess of acid functionality, amine 
functionality, etc. Typically excesses of epoxy is not preferred since 
diepoxy compounds can under certain conditions of heat and storage time, 
result in epoxyepoxy crosslinking. Gelling tendencies and theoretical 
molecular weight calculations can be made using the estimation methods 
found in Flory, Principles of Polymer Chemistry, Cornell University Press 
(1953), pp. 317-398. 
In preparing epoxy adduct compositions which can be added to conventional 
hot melt adhesive compositions to form stable adhesive compositions which 
do not separate into phases, we have discovered two techniques. First, the 
epoxy adduct can be made by combining the components to produce an adduct 
having a polarity which is reflected in the average dipole moment on the 
epoxy adduct compound, similar to that of the thermoplastic polymer of the 
adhesive. It is well known that compounds of similar polarity are 
typically compatible. It is well within the skill of the art to control 
the reaction ratios of the components such as epoxy compounds, dimer acid 
compounds, monofunctional active hydrogen containing compounds and others 
to form adducts of the appropriate polarity. One preferred embodiment of 
the invention comprises hot melt adhesives made from polyalkyleneoxazoline 
polymers. Typically such polymers are compatible in hot melt compositions 
with epoxy adducts having a sufficient number of beta hydroxy groups 
formed in the epoxy reaction. Secondly, in the instance that the epoxy 
adduct comprises the reaction product of a polymer having an epoxy 
reactive hydrogen group, the base polymer can be selected from polymers in 
the same general chemical class as the base thermoplastic polymer. 
Accordingly, if the base thermoplastic polymer comprises an ethylene vinyl 
acetate copolymer, the adduct can be made from an ethylene vinyl acetate 
polymer. Similarly, if the thermoplastic base polymer is a styrene 
butadiene styrene polymer, the adduct can be made from a styrene 
containing copolymer. 
Hot Melt Adhesive Compositions 
The novel adhesive additive composition of the invention can be used in hot 
melt adhesive formulations at an effective amount to increase the 
adhesivity, compatibility, or other beneficial property of the adhesive 
composition. 
The hot melt adhesives of the invention can also contain plasticizers, 
inorganic extenders, organic extenders, oils, UV absorbers, heat 
stabilizers, flavorings, release agents, waxes, antiblocking agents, and 
antioxidants. 
The base thermoplastic polymers useful in the hot melt adhesives are 
described above. 
Typically thermoplastic base polymers have insufficient pressure sensitive 
properties for use as a pressure sensitive adhesive, tackifying agents are 
typically added to base polymer compositions in order to introduce tack 
into the composition. Tackifying agents are believed to increase the 
ability of the adhesive composition to "wet" the substrate surface. Many 
tackifying agents are well known in the art. Such agents include resins or 
resin blends, rosin, rosin acids, hydrogenated rosins, tall oil 
pitchheads, hydrocarbon resins, terpene resins, and others. Examples of 
preferred tackifying agents include the ESCOREZ family of resins, the 
PERMALYN family of resins, the SYLVATAC family of resins, the NIREZ family 
of resins, and the WINGTACK family of resins. 
Plasticizers can also be used in improving the quality of the hot melt 
adhesive compositions. Plasticizers are generally classified as materials 
which can be incorporated into another material to increase its 
workability, flexibility, or distensibility. The addition of the 
plasticizer can lower melt viscosity, the temperature of the second order 
transition point, or the elastic modulus of the treated material. Many 
plasticizers are known in the art and a plasticizer can be selected for 
inclusion in the hot melt adhesives of this invention which are compatible 
with the thermoplastic base polymer. Commonly employed plasticizers 
include compounds of the following classes: adipic acid derivatives, 
azolaic acid derivatives, benzoic acid derivatives, diphenyl derivatives, 
citric acid derivatives, epoxides, glycolates, isophthalic acid 
derivatives, maleic acid derivatives, plasticizer oils, phosphorous acid 
derivatives, phthalic acid derivatives, polyesters, trimelitates, polyols. 
Preferred plasticizers include the BENZOFLEX family of plasticizers, the 
SANTICIZER family of plasticizers, and the liquid polyalkylene glycols 
having molecular weights from about 200 to 10,000. 
Waxes may also be combined with the base polymer, the epoxy adduct and 
other adhesive additives in the hot melt adhesives of this invention. 
Natural, synthetic and petroleum waxes are useful in the invention. 
Natural waxes include beeswax, and hydroxy containing waxes such as 
hydrogenated castor oil, reduced fatty acids, and other typically C.sub.12 
-C.sub.35 aliphatic hydroxy containing compositions. Synthetic waxes 
include typically low molecular weight polyethylene and Fishertropsch 
waxes, paraffin waxes, and microcrystalline waxes which can be derived 
from the refinement of petroleum residuum. Typically waxes have melting 
points in the range of about 125.degree. -250.degree. F. Such waxes can be 
used in the hot melt adhesive compositions of this invention at 
concentrations of from 0 to 30 wt-% depending on the properties desired. 
The hot melt adhesives of this invention can be formulated using from about 
10 to 55 wt-% of the thermoplastic base polymer, about 1 to 60 wt-% of a 
tackifying agent, and about 1 to 60 wt-% of the novel epoxy adduct 
adhesive additive composition of the invention. The hot melt adhesives can 
further contain an effective amount of a plasticizer, amounts of filler 
that do not degrade the adhesive properties of the hot melt adhesives of 
the invention but reduce cost, and other well known additive compositions. 
The preferred adhesive additive compositions of the invention can contain 
10 to 45 wt-% of a base polymer comprising an ethylene-vinyl acetate 
polymer, a polyethyloxazoline polymer, or an ABA block polymer having 
styrene-conjugated diene-styrene block structure, 15 to 55 wt-% of a 
compatible tackifying agent, 10 to 30 wt-% of the novel epoxy adduct 
adhesive additive composition of this invention, 0 to 30 wt-% wax, 0 to 35 
wt-% of a plasticizer, and in the instance that a polyethyloxazoline 
polymer is used, 10 to 30 wt-% of an additional hydroxy organic compound. 
An embodiment of the hot melt adhesive composition of the present invention 
suitable for providing improved adhesivity to hard-to-stick surfaces 
including fluorocarbon surfaces can comprise an effective amount of a 
thermoplastic polymer to form a hot melt adhesive; an effective tackifying 
amount of a tackifying resin; and an effective bond improving amount of a 
hot melt adhesive additive composition comprising the reaction product of: 
a polymer having at least one free epoxy reactive hydrogen; and epoxy 
compound having at least one reactive epoxy group; and an epoxy reactive 
hydrogen containing compound; wherein for each mole of reactive hydrogen 
in the polymer there are about 0.1 to 10 moles of the epoxy compound and 
about 0.1 to 10 moles of the epoxy reactive hydrogen containing reactive 
compound. 
The ethylene vinyl acetate thermoplastic polymers useful in making the hot 
melt adhesives of the invention preferably have a molecular weight in the 
range of 2,000 to 100,000, preferably 10,000 to 70,000, a melt index of 1 
to 800, a percentage of vinyl acetate that ranges from about 18 to 50, 
most preferably about 28 to 46, and typically a softening point in excess 
of about 75.degree. C. 
The polyethyleneoxazoline thermoplastic base polymer for use in making the 
hot melt adhesive of the invention comprise a polymer having a molecular 
weight of about 50 to 500,000. Most preferably, the polymers have 
molecular weights of about 50-100,000, about 150,000-250,000, and about 
300,000-350,000. 
The hot melt additive composition of the invention can be blended in 
standard hot melt processing units using standard techniques. 
The following Examples provide a basis for understanding the invention 
through a set of specific embodiments of the invention and include a best 
mode.

EXAMPLE I 
Into a standard industrial mixer equipped with an inert gas blanket and 
heater was added 83.44 parts of an ethylene-vinyl acetate-methacrylic acid 
terpolymer (25 wt-% vinyl acetate, acid number-6, melt index 500, ELVAX 
4310, duPont Chemical Co.). The polymer was heated under an inert gas 
blanket to a temperature of 350.degree. F. until melted. Into the melt 
polymer was added 15.62 parts of an epoxy resin comprising a bisphenol 
A-epichlorohydrin reaction product (EPON 1004, Shell Chemical Co.). The 
epoxy resin was blended into the melt polymer until homogeneous, and about 
0.94 parts of diethanolamine was added to the melt mixture at high mixing 
rates. The melt mixture was maintained at 350.degree. F. for 2 hours. The 
appearance of the product was a light tan opaque thermoplastic solid. 
EXAMPLE II 
Into a standard industrial mixer equipped with an inert gas blanket and 
heater was added 79.7 parts of an ethylene-vinyl acetate-methacrylic acid 
terpolymer a vinyl acetate content of about 25%, a melt index of about 
170, an acid number about 4-8, and a softening point of about 195.degree. 
F. (91.degree. C.) (ELVAX 4320, duPont Chemical Co.). The mixture was 
heated to 300.degree. F. to melt the polymer. Into the polymer melt was 
added a C.sub.36 (Ave.) aliphatic dibasic dimer acid made from C.sub.38 
(Ave.) unsaturated fatty acids (EMPOL 1014 dimer acid) having an acid 
value of about 196, a suponification value of 198, and an approximate 
molecular weight of about 565. The mixture was agitated until homogeneous 
and into the homogeneous melt was added 9.6 parts of an epoxy resin 
comprising a liquid bisphenol A-epichlorohydrin (EPON 828, Shell Chemical 
Co.). The mixture was blended until homogeneous and into the blend was 
added 0.89 parts of diethanolamine. The mixture was agitated until 
homogeneous, heated to 350.degree. F., and stirred at high mixing speed 
for 1 hour. The reaction product was a light tan opaque thermoplastic 
mass. 
EXAMPLE III 
Into a standard industrial mixer equipped with an inert gas blanket and a 
heater, was added 79.7 parts of an ethylene vinyl acetate-methacrylic acid 
terpolymer (about 25 wt-% vinyl acetate, an acid number of about 6, and a 
melt index of about 500, ELVAX 4310, duPont Chemical Co.). The mixer was 
operated until the polymer was melted and into the melt was added 9.8 
parts of a dimer acid made from a C.sub.18 (Ave.) unsaturated fatty acid 
(EMPOL 1014, Emery). The mixer was operated until a mixture was 
homogeneous and into the melt was added 9.6 parts of an epoxy resin 
comprising a liquid bisphenol A-epichlorohydrin adduct (EPON 828, Shell 
Chemical Co.). The mixer was operated until the mixture was homogeneous 
and into the melt mixture was added 0.9 parts of diethanolamine. The 
homogeneous mixture was heated to 350.degree. F. for 1 hour. At the end of 
that period the mixture was removed. 
EXAMPLE IV 
Into a standard industrial mixer equipped with an inert gas blanket and a 
heater was added 68.63 parts of an ethylene-vinyl acetate-acrylic acid 
terpolymer (25 wt-% vinyl acetate, acid number-6, melt index 500, ELVAX 
4310, duPont Chemical Co.). The polymer was heated under the inert gas 
blanket to a temperature of 350.degree. F. until melted. Into the melt 
polymer was added a C.sub.36 (ave.) aliphatic dibasic dimer acid made from 
a C.sub.18 (ave.) unsaturated fatty acid (EMPOL 1014 dimer acid) having an 
acid value of about 196, a saponification value of 198, and an approximate 
molecular weight of 565. The mixture was agitated until homogeneous and 
into the homogeneous melt was added 13.8 parts of an epoxy resin 
comprising a diglycidyl ether of bisphenol A (EPON 828, Shell Chemical 
Co.). The mixture was blended until homogeneous and into the blend was 
added 0.77 parts of diethanolamine. The mixture was agitated until 
homogeneous, heated to 350.degree. F., and stirred at high mixing speed 
for 1 hour. The reaction product was a light tan opaque thermoplastic 
mass. 
EXAMPLE V 
Example IV was repeated except that 77.9 parts of ELVAX 4310, 11.9 parts of 
EMPOL 1014, and 7.83 parts of EPON 828 were used in addition to 2.08 parts 
of CARDURAE, a C.sub.12-14 tertiary carboxylic acid-epichlorohydrin adduct 
and 0.25 parts of a benzyldimethylamine catalyst. 
EXAMPLE VI 
Example V was repeated except that 79.4 parts of ELVAX 4310, 9.71 parts of 
EMPOL 1014, and 9.57 parts of EPON 828 were used. The CARDURAE was omitted 
and 1.10 parts of heptanoic acid was substituted. 
EXAMPLES VII-XXVIII 
The following ethylene-vinyl acetate based hot melt adhesives were prepared 
using the proportions shown in the following Tables. Typically the hot 
melt adhesives were formulated in standard hot melt blending equipment 
with standard techniques. The Tables are shown in parts by weight. The 
adhesive properties of the adhesives are also shown in the Table. Such 
properties include viscosity at 250.degree. , 300.degree. , 350.degree. , 
and 400.degree. F. The 100 gram peel and 500 gram shear test shows the 
temperature at which the adhesive bond fails when subjected to the test 
method. The adhesive was used to bond to fluorocarbon coated board bonded 
at 350.degree. F. conditioned for 24 hours and tested for its adhesive 
properties at substantially reduced temperature. 
__________________________________________________________________________ 
Examples VII-XIV 
Parts by Weight 
VII VIII IX X XI XII XIII XIV 
__________________________________________________________________________ 
Permalyn 105 50 50 50 50 45 45 50 50 
Benzoflex 50 2 
Unilin 405 10 
Unilin 550 10 15 20 
Ex. III 20 20 20 
Ex. IV 20 20 20 20 
Ex. V 
Ex. VI 
EVA** 
28% VA 400 MI*** 35 
EVA** 
33% VA 43 MI 30 30 
EVA** 
46% VA 90 MI 20 20 20 20 30 
EVA** 
28% VA 800 MI 8 
EVA** 
Elvax 4310 
Viscosity (cps) 
at 
250.degree. F. 
34,000 68,000 
36,500 
4,400 
300.degree. F. 
8,200 
64,000 20,750 
9.360 
1.675 
55,000 
350.degree. F. 
3,060 
21,000 7,360 763 18,750 
400.degree. F. 
1,275 
8,200 3,150 400 7,800 
100 g. peel 130.degree. F. 
134.degree. F. 
124.degree. F. 
114.degree. F. 
130.degree. F. 
133.degree. F. 
116.degree. F. 
132.degree. F. 
500 g. shear 160.degree. F. 
148.degree. F. 
155.degree. F. 
126.degree. F. 
159.degree. F. 
187.degree. F. 
127.degree. F. 
144.degree. F. 
Fluorocarbon coated board; 
bonded at 350.degree. F.; 
conditioned for 24 hours 
0.degree. F. 100% ft* 
100% ft 
100% ft 
100% ft 
100% ft 
no ft 
100% ft 
100% ft 
-20.degree. F. 
100% ft 
100% ft 
100% ft 
100% ft 
100% ft 100% ft 
-25.degree. F. 
100% ft 
100% ft 100% ft 100% ft 
20% ft 
__________________________________________________________________________ 
Examples XV-XVIII 
Parts by Weight 
XV XVI XVII XVIII 
__________________________________________________________________________ 
Permalyn 105 50 50 50 50 
Benzoflex 50 
Unilin 405 
Unilin 550 10 10 10 10 
Ex. III 
Ex. IV 
Ex. V 20 
Ex. VI 20 
EVA** 
28% VA 400 MI*** 
EVA** 
33% VA 43 MI 
EVA** 40 20 
46% VA 90 MI 
EVA** 
28% VA 800 MI 
EVA** 
Elvax 4310 20 
Viscosity (cps) 
at 
250.degree. F. 29,800 25,600 
300.degree. F. 7,200 7,560 
350.degree. F. 2,700 2,900 5,120 2,460 
400.degree. F. 1,138 1,213 
100 g. peel 131.degree. F. 
130.degree. F. 
132.degree. F. 
128.degree. F. 
500 g. shear 163.degree. F. 
168.degree. F. 
167.degree. F. 
164.degree. F. 
Fluorocarbon coated board; 
bonded at 350.degree. F.; 
conditioned for 24 hours 
0.degree. F. 100% ft* 
100% ft 0% ft 0% ft 
-20.degree. F. 100% ft 100% ft 15% ft 0% ft 
-25.degree. F. 
__________________________________________________________________________ 
*ft = fiber tearing bonds 
**EVA = ethylene vinyl acetate copolymer 
***MI = melt index 
______________________________________ 
Examples XIX-XXII 
Parts by Weight 
XIX XX XXI XXII 
______________________________________ 
Zonester 100 40 
Polar Rosin Ester 50 
Nirez 111-105 50 
Sylvatac 295 50 
Unilin 550 20 10 10 
Ex. III 20 20 
Ex. IV 20 
EVA** 
18% VA 500 MI*** 
20 
EVA** 
28% VA 400 MI 20 
EVA** 
33% Va 43 MI 30 
EVA** 
46% VA 90 MI 20 20 
Viscosity (cps) 
at 
250.degree. F. 5,900 
300.degree. F. 2,325 
350.degree. F. 1,063 
400.degree. F. -- 
100 g. peel 130.degree. F. 134.degree. F. 
129.degree. F. 
500 g. shear 189.degree. F. 163.degree. F. 
158.degree. F. 
Fluorocarbon coated 
board; bonded at 350.degree. F.; 
conditioned for 24 hours 
-20.degree. F. 90% ft 
75% ft 
-25.degree. F. no ft 100% ft 
______________________________________ 
*ft = fiber tearing bonds 
**EVA = ethylene vinyl acetate copolymer 
***MI = melt index 
__________________________________________________________________________ 
Examples XXIII-II 
Parts by Weight 
XXIII 
XXIV XXV XXVI XXVII 
XXVIII 
__________________________________________________________________________ 
Sylvatac 105 50 50 
Escorez 2393 50 50 50 70 
Unilin 550 10 
Unilin 700 10 
Ex. I 20 
Ex. I 20 
Ex. III 20 20 
Ex. IV 20 20 
EVA** 
28% VA 800 MI*** 10 
EVA** 
33% VA 43 MI 30 30 
EVA** 
40% VA 57 MI 30 
EVA** 
46% VA 90 MI 20 20 
Viscosity (cps) 
at 
250.degree. F. 
32,750 
52,000 150,000 
300.degree. F. 
12,750 
16,500 41,000 
49,500 
350.degree. F. 
3,500 
4,700 15,500 
19,500 
400.degree. F. 
1,550 
2,150 7,200 
8,500 
100 g. peel 129.degree. F. 
127.degree. F. 
135.degree. F. 
131.degree. F. 
500 g. shear 160.degree. F. 
130.degree. F. 
147.degree. F. 
146.degree. F. 
Fluorocarbon coated board; 
bonded at 350.degree. F.; 
conditioned for 24 hours 
0.degree. F. 100% ft 
100% ft 
100% ft 
100% ft 
100% ft 
-20.degree. F. 
85% ft 
100% ft 
-25.degree. F. 25% ft 
100% ft 
100% ft 
no ft 
__________________________________________________________________________ 
*ft = fiber tearing bonds 
**EVA = ethylene vinyl acetate copolymer 
***MI = melt index 
The Examples and data clearly show that the adduct of the invention and the 
hot melt adhesives containing the adduct of the invention substantially 
improves bonding of the adhesives to fluorocarbon coated board. 
Fluorocarbon coated materials are notoriously difficult bonding media. The 
100% fiber tear bonds provided by the ethylene-vinyl acetate based 
adhesives of this invention are unusually good. 
EXAMPLE XXIX 
Into a glass jar was added 30 parts of the product of Example I. The 
contents of the jar were hand mixed and 30 parts of the polyethyloxazoline 
polymer having a molecular weight of about 80,000 (PeOx, Dow Chemical Co.) 
were added. Into the blend was added 40 parts of a distilled tall oil 
rosin, ACTINOL (SPR-Arizona Chemical Co.). The blend was heated in a 
350.degree. F. oven and hand mixed until uniform, resulting in a uniform, 
single phase, medium brown cloudy thermoplastic solid. The composition was 
used as adhesive to bond paper on paper. The adhesive had an acceptable 
open time and was repulpable. 
Using the procedure of Example XXII the following adhesives were prepared. 
TABLE II 
______________________________________ 
PeOx Hot Melt Adhesives 
XXIX-A XXIX-B XXIX-C XXIX-D XXIX-E 
______________________________________ 
PeOx 30 30 30 30 30 
(low m.w.) 
Actinol tall 
oil resin 
40 40 40 40 40 
Ex. III 30 
Ex. V 30 
Ex. VI 30 
Ex. I 30 
Elvax 4310 30 
______________________________________ 
All the adhesives in Table II except for XVIIE, were uniform light brown 
thermoplastic masses that formed paper to paper fiber tearing bonds. The 
product of Example XVIIE would separate into phases upon standing at 
elevated hot melt temperatures. The adhesives were of acceptable viscosity 
and were repulpable in aqueous solution. 
EXAMPLE XXX 
Into a high shear mixer was placed 188.36 grams, 0.0013 equivalent of a 
carboxylated styrene-butadiene block copolymer having an equivalent weight 
of about 140,000, 15 wt-% styrene and an acid number of 0.4. The polymer 
was mixed and heated to 350.degree. F. and into the hot mass was added 
5.06 grams, 0.027 equivalents of a liquid bisphenol A-epichlorohydrin 
adduct (EPON 828) and 6.16 grams, 0.052 equivalents of a dimer acid (EMPOL 
1014). Mixing was continued until the blend was uniform and into the blend 
was added 0.42 grams, 0.004 equivalent of diethanol amine. The mixture was 
reacted with stirring for 1 hour. The resulting product was a light tan 
thermoplastic mass. 
EXAMPLE XXXI 
Example III was repeated except that 37.29 parts of a dimer acid (EMPOL 
1014), 49.02 parts of a liquid bisphenol-A-epichlorhydrin adduct (EPON 
820) and 13.69 parts of diethanol amine were substituted for the reactants 
of Example III. 
The above Examples, discussion and test data describe the invention. 
However, since many embodiments of the invention can be made without 
departing from the spirit and scope of the invention, the invention 
resides in the claims hereinafter appended.