EN 923:2005

SLOVENSKI STANDARD
01-januar-2006
1DGRPHãþD
SIST EN 2243-2:1998
SIST EN 923:1999
Lepila – Izrazi in definicije
Adhesives - Terms and definitions
Klebstoffe - Benennungen und Definitionen
Adhésifs - Termes et définitions
Ta slovenski standard je istoveten z: EN 923:2005
ICS:
01.040.83 Gumarska industrija in Rubber and plastics
industrija polimernih industries (Vocabularies)
materialov (Slovarji)
83.180 Lepila Adhesives
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 923
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2005
ICS 83.180 Supersedes EN 923:1998
English Version
Adhesives - Terms and definitions
Adhésifs - Termes et définitions Klebstoffe - Benennungen und Definitionen
This European Standard was approved by CEN on 12 September 2005.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national
standards may be obtained on application to the Central Secretariat or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation
under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
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COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 923:2005: E
worldwide for CEN national Members.

Contents Page
Foreword .3
Introduction.4
1 Scope .5
2 Terms and definitions.5
2.1 Adhesives.5

2.2 Functional adhesive components.9
2.3 Chemical base products.12
2.4 Adhesive properties.20
2.5 Material and material treatment .24
2.6 Bonding .26
2.7 Bond properties .32
Annex A (informative) Adhesives.36
Annex B (informative) Adhesives joints .38

Foreword
This European Standard (EN 923:2005) has been prepared by Technical Committee CEN/TC 193
“Adhesives”, the secretariat of which is held by AENOR.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by April 2006, and conflicting national standards shall be withdrawn at the
latest by April 2006.
This European Standard supersedes EN 923:1998.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland
and United Kingdom.
Introduction
This European Standard comprises terms peculiar to, or in general use in, the adhesive and adhesive
processing industry.
The terms defined have been classified so that, as far as possible, related concepts (adhesives, functional
adhesive components, chemical base products, adherents, adhesives properties, bonding, and bond
properties) are grouped together. All definitions are numbered and an alphabetical index which includes all
terms is provided at the end of this European Standard.
The numbering of the individual definitions is the same in all three versions (English, French and German) of
this European Standard. Consequently this European Standard can be used as a dictionary, combined with
one or both of the other versions as an aid for translation of terms into French or German, as a source of
information about related concepts in the adhesive industry or to provide a term for a concept.
In order to find:
a) the definition of a term; look up the term in the alphabetical index at the end of this European Standard.
The index will refer to the number in this European Standard. The definition, the term and any synonyms
appear by the number;
b) information about related terms; look up the term in the alphabetical index to find its number in this
European Standard. When the term has been located in this European Standard, the related concepts
can be found in the same subdivision;
c) the translation of a term into the French or German language; look up the number of this term in this
European Standard and locate the translation of the term and the definition under the same number in the
standard of the foreign version.
1 Scope
This European Standard defines terms used in the adhesive industry and terms relating to adhesives in those
industries that use adhesives.
2 Terms and definitions
2.1 Adhesives
2.1.1
adhesive
non-metallic substance capable of joining materials by surface bonding (adhesion), and the bond possessing
adequate internal strength (cohesion)
NOTE Many adhesives names refer to their main functional components;
 the physical nature of the adhesive.
Table A.1 lists main binders, temperature and mode of setting of these adhesives and the number of parts that have to be
mixed before use. Some other names refer to
 the method of application, or
 mode of setting.
Furthermore adhesives are named according to points of less significance:
 field of application (e.g. footwear adhesive, construction adhesive, packaging adhesive),
 material to bond (e.g. paper adhesive, wood adhesive, wall paper adhesive, rubber adhesive),
 place of application (e.g. in situ adhesive),
 speed of setting (e.g. instant adhesive),
 bond properties (e.g. structural adhesive),
 shape (e.g. powder adhesive, pearl glue, table glue for solid glue, adhesive film for shaped adhesive, or stick
adhesive for stick shaped adhesives), or
 aspect (e.g. white glue).
2.1.2
water-borne adhesive; aqueous adhesive
adhesive in which the solvent, or the continuous phase is water
2.1.3
glue
aqueous adhesive specifically designed for bonding of wood and other porous substrates
NOTE A glue can be based on a natural product like protein or synthetic resins (UF, PF or PVAC, see 2.3.51, 2.3.52
and 2.3.30 respectively)
2.1.4
paste adhesive
adhesive of a non-stringy, highly viscous nature
NOTE Paste adhesives based on starch or cellulose ethers are usually applied for paper bonding (e.g. paper bags or
wall paper), based on synthetic polymers for bonding floor coverings.
2.1.5
dispersion adhesive
adhesive consisting of a stable dispersion of a polymer in a liquid continuous phase, usually water
NOTE Dispersion adhesives containing an elastomer as polymer conventionally are often termed "latex".
2.1.6
emulsion adhesive
adhesive consisting of a stable emulsion of a liquid hydrophobic resin in water
2.1.7
solvent-borne adhesive; solution adhesive, solvent-based adhesive
adhesive in which the binder is dissolved in a volatile organic solvent
NOTE In practice solvents used for solvent-borne adhesives have boiling points below 170 °C at 101,3 kPa and a
vapour pressure greater than 50 Pa at 20 °C and, if flammable, a flash point below 55 °C.
2.1.8
solvent free adhesive
adhesive that is substantially free from organic solvents (see 2.1.7)
NOTE "Substantially free" means that organic solvents have neither been added in the basic elements of an
adhesive nor during its process of manufacture out of these basic elements. "Low solvent adhesives" contain at most 5 %
of solvents based on total weight of the adhesive.
2.1.9
plastisol adhesive
adhesive material formed by the dispersion of a polymer in a plasticizer such that, when the dispersion is
heated, the polymer dissolves irreversibly in the plasticizer to form a solution that solidifies on cooling
2.1.10
toughened adhesive
adhesive which by virtue of its physical structure discourages propagation of cracks
NOTE The toughening can be achieved, for example, by the creation of a discrete elastomeric phase within the
adhesive matrix.
2.1.11
spray adhesive
adhesive that is projected in small particles by means of a pressure medium
2.1.12
gap-filling adhesive
adhesive designed for filling wider gaps between uneven surfaces
NOTE For high strength load-bearing purposes, e.g. in the car industry, the adhesive will provide satisfactory bond
strength in bond-lines up to 1 mm in thickness. For the construction industry, high solid adhesives designed for use
between uneven surfaces and to bond satisfactorily in gaps up to 6 mm are used.
2.1.13
sealant
adhesive material, used to fill gaps where movement can occur in service and which, when set, has elastic
properties
NOTE The term "sealant" is also used for a material filling a void against the ingress or egress of a fluid under
pressure.
2.1.14
film adhesive
adhesive in film form, with or without a carrier
NOTE Film adhesives set usually by means of heat under pressure.
2.1.15
foaming adhesive
adhesive designed to foam in situ, after application, in order to provide extensive gap-filling properties
2.1.16
unsupported film adhesive
adhesive supplied in sheet, film or web, without an incorporated carrier
2.1.17
supported film adhesive
adhesive supplied in sheet or film form with an incorporated carrier that remains in the bond when the
adhesive is applied and used
NOTE The carrier can be woven or non-woven material consisting of organic or inorganic fibres.
2.1.18
adhesive tape
flexible backing or carrier coated with a pressure-sensitive, remoistable, or heat activatable adhesive
2.1.19
transfer tape
carrier coated with a pressure-sensitive adhesive which, when detached from the substrate, permits the
carrier to be removed leaving only the adhesive
2.1.20
double coated adhesive tape; double sided adhesive tape
tape where the adhesive is applied on both sides of the carrier
2.1.21
multiple-layer adhesive
film adhesive, usually supported with a different adhesive composition on each side
NOTE Multiple-layer adhesives are designed to bond dissimilar materials.
2.1.22
encapsulated adhesive
adhesive in which particles or droplets of the adhesive or an adhesive component are enclosed in a protective
film (microcapsules) usually to prevent cross-linking until the film is destroyed by suitable means
2.1.23
one-way stick adhesive
adhesive that is applied to only one of the adherends
2.1.24
separate application adhesive
adhesive consisting of different components which are applied separately to adherends
NOTE Pressing together the components initiates a chemical reaction curing the bond-line.
2.1.25
two way stick adhesive, double spread adhesive
adhesive that is applied to both adherends
2.1.26
one part adhesive
adhesive ready for use
NOTE A one-part adhesive can require the addition of water or the presence of ambient moisture for setting.
2.1.27
two part adhesive
adhesive that consist of two separate reactive components that are mixed before use
2.1.28
multi-part adhesive
adhesive that consists of two or more separate reactive components that are mixed before use
2.1.29
contact adhesive
adhesive that is applied to both adherends and when allowed to become apparently dry will instantly develop
a firm bond when a firm but not sustained pressure is applied
NOTE "apparently dry" means that the adhesive coats are "dry to touch" at some stage in the evaporation of volatile
constituents.
2.1.30
hot melt adhesive
adhesive that is applied in the molten state and forms a bond on cooling to a solid state
2.1.31
heat activated adhesive
adhesive pre-applied to the adherends that is rendered tacky prior to use by application of heat and forms a
bond on cooling under pressure
2.1.32
heat sealing adhesive
adhesive pre-applied to one or both adherends that is activated by the application of heat and forms a bond
on cooling
NOTE Heat-sealing adhesives are commonly used in the packaging industry.
2.1.33
solvent activated adhesive
adhesive pre-applied to an adherend that is rendered tacky immediately prior to use by the application of
solvent
2.1.34
pressure sensitive adhesive
adhesive which in a dry state is permanently tacky at room temperature and adheres readily to surfaces under
light and brief pressure
NOTE Pressure-sensitive adhesives are used among other things for the manufacture of pressure sensitive tapes.
2.1.35
cold setting adhesive (cold glue deprecated)
adhesive that sets without the application of heat
2.1.36
hot setting adhesive
adhesive that sets only with the application of heat

2.1.37
reaction adhesive, reactive adhesive
adhesive that sets by a chemical reaction of its components and/or the action of external agents
2.1.38
cold curing adhesive
adhesive that cures without the application of heat
2.1.39
hot curing adhesive
adhesive that cures only with the application of heat
2.1.40
self curing adhesive
adhesive that cures, after application, under specified conditions
2.1.41
anaerobic adhesive
adhesive that cures in absence of oxygen, curing being inhibited by the presence of oxygen and catalysed by
metal ions
2.1.42
moisture curing adhesive
adhesive that cures by reaction of water from the air or from an adherend
2.1.43
conductive adhesive
adhesive especially designed to either avoid the accumulation of an electrical charge or to conduct an
electrical current
2.1.44
adhesive batch
quantity of a particular adhesive (or component of an adhesive) manufactured in a single location at a defined,
limited time and under uniform conditions
NOTE "Lot" is a commonly used commercial term. A lot can consist of less or more than one batch.
2.2 Functional adhesive components
2.2.1
binder
component of an adhesive that is primarily responsible for the adhesion and cohesion
2.2.2
monomer
chemical compound, usually of low molecular mass, that can be converted into a polymer by combining with
itself or with other chemical compounds
2.2.3
polymer
substance composed of molecules characterized by the multiple repetition of one or more species of atoms or
groups of atoms (constitutional units) linked to each other in amounts sufficient to provide a set of properties
that do not markedly vary with the addition or removal of one or a few of the constitutional units
NOTE The nature of these constitutional units, their order and the average number per molecule influence the
physical and mechanical properties of the polymer.
2.2.4
copolymer
polymer derived from more than one species of monomer
2.2.5
elastomer
macromolecular material which returns rapidly to approximately its initial dimensions and shape after
substantial deformation by a weak stress and release of the stress at room temperature
2.2.6
resin
solid, semi solid or pseudosolid organic material that has an indefinite and often high relative molecular mass,
exhibits a tendency to flow when subjected to stress, usually has a softening or melting range, and usually
fractures conchoidally
NOTE 1 In a broader sense, the term is used to designate any polymer that is basic material for plastics. Bitumen,
pitches and waxes are excluded by convention.
NOTE 2 Some resins may be part of a reaction adhesive (see 2.1.37).
2.2.7
synthetic resin
resin derived from a synthetic monomer
2.2.8
thermoplastic resin, thermoplast
polymer or copolymer capable of being softened by heating and hardened by cooling
NOTE Softening and hardening are repeatable. Many thermoplastic materials can become thermoset by appropriate
treatment to induce crosslinking, e.g. by the addition of a suitable chemical crosslinking agent or by irradiation.
2.2.9
thermosetting resin, thermoset
monomer, polymer or copolymer, which when cured, changes into a substantially infusible and insoluble
product
NOTE The setting of a thermosetting resin undergoes three different stages: the "A-stage" at which the material is
still fusible and still soluble. The intermediate pseudo-stable "B-stage" at which it is fusible and partially soluble. The "B-
stage" is converted to the final crosslinked, insoluble and infusible "C-stage" by application of heat and, usually, pressure.
2.2.10
crosslinking agent
substance that causes, promotes or regulates the formation of intermolecular, covalent or ionic bonds
between polymer chains resulting in a three dimensional molecular network
NOTE Crosslinking can occur either between polymer chains or by reaction of simple functional molecules (e.g. two
part polyurethane or epoxy adhesives). Crosslinking can also be produced by radiation or oxidation. The terms "hardener"
and "curing agent" are often used synonymously with crosslinking agent.
2.2.11
adhesion promotor; coupling agent
substance used in small proportions to increase the adhesion to specific substrates
2.2.12
accelerator
substance used in small proportions to increase the reaction rate of a chemical system (reactants, plus
additives)
2.2.13
catalyst
substance used in small proportion, that augments the rate of a chemical reaction, and in theory remains
unchanged chemically at the end of the reaction

2.2.14
inhibitor
substance used in small proportions to suppress a chemical reaction
2.2.15
retarder
substance used in small proportions to reduce the reaction rate of a chemical system
2.2.16
antioxidant
substance used to retard deterioration caused by oxidation
2.2.17
flexibilizer; internal plasticizer
co-reactant which, when incorporated into a polymer confers improved flexibility and resilience to the polymer
NOTE A flexibilizer provides to the adhesive film a greater extension at break, a lower modulus and a lower
temperature at which it becomes brittle. A flexibilizer is not extractable and will not migrate from the adhesive film.
2.2.18
plasticizer; external plasticizer
non-reactive substance incorporated into an adhesive to improve flexibility and resilience of its bond.
NOTE A plasticizer provides to the adhesive film a greater extension at break, a lower modulus and a lower
temperature at which it becomes brittle. A plasticizer can be soluble and can migrate from the adhesive film.
2.2.19
solvent
liquid or mixture of liquids that are used in the manufacture of adhesives to dissolve or to dilute the binder
without chemical change
NOTE Solvents are used to control the consistency and character of the adhesive and can regulate application
properties.
2.2.20
diluent (thinner, deprecated)
liquid whose sole function is to reduce the concentration of solids and viscosity of an adhesive
2.2.21
reactive diluent
low-viscosity liquid added to a high-viscosity solvent-free adhesive which reacts chemically with the adhesive
during setting
NOTE A reactive diluent is usually mono-functional and reduces the viscosity of the adhesive with acceptable
changes in other properties.
2.2.22
filler
relatively inert solid material added to a plastic or an adhesive to modify strength, permanence, working
properties or other quality
NOTE 1 Two classes of fillers are used:
 chemically inert fillers, e.g. china clay or woodflour;
 "reinforcing fillers" like silicates, carbon black, fibrous materials or aluminium powder that markedly enhance the per-
formance of a polymer.
NOTE 2 A filler only used to reduce cost is termed “extender”. An extender can be a liquid.
2.2.23
matrix
part of an adhesive that surrounds or engulfs embedded filler or reinforcing particles and filaments
2.2.24
modifier
ingredient which, when added to an adhesive, changes its properties
NOTE The term modifier includes fillers, diluents, plasticizers and tackifiers.
2.2.25
stabilizer
substance used in the formulation of some plastics or adhesives to assist in maintaining the properties of the
material or of the adhesive and its bonds at or near their initial values during storage and processing and
under service conditions
NOTE Special stabilizers are used to prevent or slow down undesirable effects such as coagulation, excessive
reactivity, absorption by adherends or destruction of adherends.
2.2.26
emulsifier; emulsifying agent; dispersant
surface-active substance that promotes and maintains the dispersion of two incomplete miscible liquids or a
solid and a liquid by reducing the interfacial tension between the two phases
2.2.27
tackifier
substance intended to enhance the tack or the tack range of an adhesive coat
2.3 Chemical base products
2.3.1
soluble silicate
silicate obtained by melting a purified silica with an alkali salt
2.3.2
hydraulic cement
inorganic adhesive material that sets and hardens by chemical interaction with water and that is capable of
doing so under water
NOTE 1 Hydraulic cements set chemically by "hydration" thus forming compounds with strength-producing properties.
There are several types of hydraulic cements:
 “Portland cement“, produced by pulverizing partially fused "clinker" consisting primarily of hydrated calcium silicates,
and usually containing calcium sulfate in any hydration state (anhydrite, gypsum, hemihydrate);
 “natural cement“, produced by calcining a naturally occurring argillaceouse limestone at a temperature below the
sintering point and then grinding to a fine powder;
 “slag cement“, consisting mostly of an intimate and uniform blend of granulated blast-furnace slag and hydrated lime
in which the slag constituent is more than a specified minimum percentage. Blast-furnace slag is the non-metallic
product consisting essentially of silicates and aluminosilicates of calcium and other bases that is developed in a
molten condition simultaneously with iron in a blast furnace;
 “Portland-Pozzolan cement“, consisting of an intimate and uniform blend of Portland cement or Portland blast-furnace
slag cement and fine pozzolan, in which the amount of the pozzolan constituent is within specified limits. Pozzolan is
a siliceous and aluminous material which in itself possesses little or no cementitious value but which will, in finily
divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to
form compounds possessing cementitious properties.
NOTE 2 "Concrete" is composite material that consists essentially of a binder (e.g. hydrated cement and water) within
which are embedded particles of fragments or aggregates.
NOTE 3 The term "cement" is also used as a synonym for organic adhesives but its use is strongly deprecated.
2.3.3
protein
natural product having the repeating linkage -NH-CO-
NOTE Some examples are:
 Soya bean protein is obtained from soya bean seeds. When compounded with other reactants it is used as an
adhesive, mostly in plywood.
 "Casein" is protein precipitated from skimmed milk by the action of rennet or acid. When compounded with other
reactants it is used as an adhesive for wood and packaging applications.
 "Collagen" is produced from collagenous animal materials like skin, bone and connective tissue.
 "Gelatine" is a soluble protein derived from collagen.
 "Animal glue" is an impure protein obtained by hydrolysis of collagenous materials by various methods and is
predominantly used for bonding of wood and other porous substrates.
2.3.4
starch
vegetable carbohydrate occurring in the granular form in certain plants and corresponding to a polymer
composed almost exclusively of anhydroalpha-D-glucose groups
2.3.5
starch ether
modified starch in which the hydroxyl groups of the starch have been totally or partially etherified
2.3.6
starch ester
modified starch in which the hydroxyl groups of the starch have been totally or partially esterified
2.3.7
dextrin(e)
modified starch prepared from starch by heat treatment in the dry state with or without the addition of small
quantities of chemical agents
NOTE Dextrin is used in certain water-borne adhesives.
2.3.8
cellulose esters
products of esterification of certain of the hydroxyl groups of the cellulose macromolecule with organic or
mineral acids
NOTE Examples of cellulose esters are cellulose acetate, cellulose acetobutyrate, cellulose acetopropionate,
cellulose nitrate. Cellulose esters are soluble in organic solvents such as esters or ketones, and thus form the basis of
some solvent-borne adhesives.
2.3.9
cellulose ethers
products of etherification of certain of the hydroxyl groups of the cellulose macromolecule
NOTE Examples of cellulose ethers are carboxymethyl cellulose, methyl cellulose, hydroxyethyl- and hydroxypropyl
cellulose. Cellulose ethers are soluble in, or solubilized by water and simple alcohols and find use as the basis of water
soluble adhesives for paper and as thickening agents in water-borne adhesives.
2.3.10
gum
water-soluble vegetable resin
NOTE Gums are dried exudations of plants or modified vegetable products.
 "Gum arabic" is the dried exudation from the stem and the branches of Acacia senegal Willdenow and other species
of acacia.
 "Gum tragacanth" is the dried mucilaginous exudation from Astragalus gummifer and other species of astragalus
(leguminosae), and which is partly soluble in water. Gum tragacanth is used as a modifier and stabilizer in water (or
occasionally alcohol) borne adhesives.
 "Cellulose gum" is a water-soluble cellulose derivative used as a substitute for gum arabic.
 "British gum" is a special type of dextrin normally used in textile sizing.
 "Mucilage" is a solution of a gum in water.
2.3.11
dammar resin
is obtained from species of Shorea, Hopea, and Balnocarpus
NOTE Dammar resin is soluble in certain organic solvents and used as a tackifier and modifier of pressure-sensitive
adhesives.
2.3.12
terpene resin
pale thermoplastic polyterpene hydrocarbons obtained by the acid catalysed polymerization of bicyclic
monoterpene ß-pinene (or occasionally α-pinene) products of the distillation of sulphate-cellulose-turpentine
NOTE Terpene resin is principally used in adhesives as a tackifier. Hydrogenated and polymerized grades are
available.
2.3.13
tall resin
essentially consisting of abietic acid and its isomers obtained from pine trees by the sulphate-cellulose-
process
2.3.14
rosin; colophony
resin essentially consisting of abietic acid and its isomers obtained as a residue in the distillation of crude
turpentine from the sap of pine tree ("gum rosin") or from an extract of the stumps and other parts of the tree
("wood rosin")
NOTE Resinous esters of rosin with polyhydric alcohols such as glycerol or pentaerythritrol ("ester gum") are
sometimes used as a tackifier. Hydrogenated and polymerized rosin grades are available.
2.3.15
natural rubber (NR)
solid material with elastic properties obtained from the botanic source Hevea brasiliensis
NOTE Cis-1,4-polyisoprene is the main constituent of NR.
2.3.16
cyclized rubber
isomeric derivative of natural rubber produced by a variety of chemical treatments
NOTE The products are resinous and are used as rubber-to-metal adhesives.
2.3.17
chlorinated rubber
white powder or fibrous product obtained by the controlled chlorination of natural rubber
NOTE Chlorinated rubber is used as a compounding ingredient in solvent adhesives.
2.3.18
carnauba wax
naturally occurring wax from the leaves of the Brasilian wax palm (Copernica cerifera)
NOTE Carnauba wax is frequently used as a constituent of release agents.
2.3.19
bitumen; asphalt
very viscous liquid or solid consisting essentially of hydrocarbons and their derivatives.
NOTE Bitumen is soluble in carbon disulphide. It is substantially non-volatile and softens gradually when heated.
Bitumen is black or brown in colour and possesses waterproofing and adhesive properties. Bitumen is obtained by refinery
process from petroleum, and is also found as a natural deposit or as a component of naturally occurring asphalt.
2.3.20
wax (synthetic)
range of low temperature melting, low molecular mass solid aliphatic hydrocarbons
NOTE Waxes are commonly used in hot-melt adhesives mainly to lower cost and reduce viscosity. Properties
affected by the waxes are blocking characteristics, softening point, bonding range and cohesive strength. Waxes are
obtained either by refinery process or in polyethylene production. Waxes mainly used are paraffin wax and microcrystalline
wax.
2.3.21
hydrocarbon resin
type of thermoplastic resin obtained by polymerization of petrol crack fractions rich in cyclic unsaturated
hydrocarbons
NOTE The fractions used are rich in cyclo pentadiene, methyl styrene, coumarone, indene, their homologues, and
their derivatives.
2.3.22
coumarone-indene resin
type of thermoplastic resin obtained by the acid catalysed polymerization of coaltar petroleum fractions rich in
coumarone, indene, their homologues, and their derivatives
NOTE Coumarone-indene resin is often used as a tackifier.
2.3.23
polyolefin
thermoplastic polymer produced by the polymerization or copolymerization of olefins (e.g. ethylene,
propylene)
2.3.24
polyethylene (PE)
thermoplastic polymer of ethylene in which the main chain repeating unit is -CH -CH -
2 2
NOTE Polyethylene is used among others for hot-melt adhesives.
2.3.25
polypropylene (PP)
thermoplastic polymer of propylene in which the main chain repeating unit is -CH-(CH ) - CH
3 2
2.3.26
chlorosulphonated polyethylene (CSM)
elastomeric polymer prepared by simultaneous chlorination and chlorosulphonation of polyethylene in solution
with gaseous chlorine and sulphur dioxide
2.3.27
polyisobutylene (PIB)
product of the polymerization of isobutylene (2-methylpropene) in which the main chain repeating unit is
-CH -C(CH ) -
2 3 2
NOTE Polyisobutylene is sometimes used as the basis of solvent-borne adhesives giving films with pressure
sensitive or self-sealing properties, and as a modifier.
2.3.28
polystyrene (PS)
thermoplastic polymer produced by the polymerization of styrene
NOTE Polystyrene is used amongst others in solution in organic solvent as an adhesive for polystyrene and certain
porous materials.
2.3.29
vinyl resin
thermoplastic polymer based on vinyl compounds CH = CH-R in which the main chain repeating unit is
-CH -CH-R-
NOTE The term "vinyl resin" is normally used for polymers based on vinyl chloride, vinyl acetate and the theoretical
vinyl alcohol. Strict polymer science nomenclature would include any polymer derived from other vinyl compounds, e.g.
polystyrene.
2.3.30
poly(vinyl acetate) (PVAC)
thermoplastic polymer in either dispersion, resinous or solid form produced by the polymerization of vinyl
acetate as sole or principal monomer
NOTE Polyvinyl acetate is used as a versatile adhesive for porous materials, particularly for wood and paper, and for
general packaging work.
2.3.31
polyethylene-vinyl acetate (EVAC)
thermoplastic polymer produced by copolymerization of ethylene and vinyl acetate
NOTE Polyethylene-vinyl acetate can be used as a solid in hot-melt adhesives or as dispersion in water-borne
adhesives.
2.3.32
poly(vinyl alcohol) (PVAL)
water soluble thermoplastic polymer produced by the hydrolysis of poly(vinyl acetate)
NOTE Commercial poly(vinyl alcohol) usually contains some residual acetate groups. The uses of poly(vinyl alcohol)
are as follows:
 as a water-soluble adhesive for porous materials;
 as an additive in other adhesives to improve adhesion and as a stabilizer etc.;
 as a heat seal or moisture reactivation adhesive.
2.3.33
poly(vinyl acetal)
thermoplastic polymer made from poly(vinyl alcohol) by the reaction of its hydroxyl groups with acetaldehyde
NOTE The term poly(vinyl acetal) is also generically used for a class of polymers derived from polyvinyl esters in
which some or all the ester groups have been hydrolysed to hydroxyl groups and some or all of these hydroxyl groups
have been reacted with aldehydes to form acetal groups. It includes also 2.2.34 and 2.2.35.
2.3.34
poly(vinyl formal) (PVFM)
thermoplastic polymer of the poly(vinyl acetal) type made from poly(vinyl alcohol) by the reaction of its
hydroxyl groups with formaldehyde (see also 2.3.33, NOTE)
NOTE The main use of poly(vinyl formal) is as a constituent of two polymer systems to provide high strength
structural adhesives.
2.3.35
poly(vinyl butyral) (PVB)
thermoplastic polymer of the poly(vinyl acetal) type made from poly(vinyl alcohol) by the reaction of its
hydroxyl groups with butyraldehyde (see also 2.3.33, NOTE)
NOTE the main uses of poly(vinyl butyral) are as follows:
 as a constituent of two polymer systems which provide high strength structural adhesives;
 as a main component of certain hot-melt adhesives used in particular for laminated safety glass and packaging
applications.
2.3.36
poly(vinyl chloride) (PVC)
thermoplastic polymer produced by polymerization of vinyl chloride
NOTE When compounded with suitable plasticizers, adhesion promoting materials, stabilizers etc., certain types of
PVC form plastisols which can be used as flexible hot setting adhesives with gap-filling and shock-absorbing properties.
2.3.37
chlorinated poly(vinyl chloride)
poly(vinyl chloride) modified by the controlled chlorination of the polymer
NOTE Chlorinated PVC is soluble in a wide range of organic solvents and used in adhesives for bonding plastics,
particularly for bonding un-plasticized polyvinyl chloride.
2.3.38
polyacrylate; polyacrylates
polymers and copolymers where at least one constitutional unit is derived from acrylic acid CH = CH - COOH
or its esters CH = CH - COOR
NOTE Polymers of this class find outlets as constituent of many types of solvent-borne adhesives and emulsion
adhesives.
2.3.39
polymethacrylates
polymers and copolymers where at least one constitutional unit is derived from methacrylic acid
CH = C(CH ) - COOH or its esters CH = C(CH ) - COOR
2 3 2 3
2.3.40
cyanoacrylate monomer
special type of acrylic monomer esters having the general formula CH = C(CN) - COOR
NOTE Cyanoacrylate monomers are capable of polymerizing rapidly in form of thin films and are used for certain
fast-setting polymerizing adhesives.
2.3.41
acrylonitrile-butadiene rubber (NBR); nitrile rubber; nitrile-butadiene
range of synthetic rubbers made by the copolymerization of 1,3-butadiene and acrylonitrile
NOTE Depending on their acrylonitrile content these rubbers have oil and solvent resistant properties. Suitably com-
pounded they are used as a basis for solvent-borne adhesives. NBR is also available as latices allowing the manufacture
of dispersion adhesives. Acrylonitrile-butadiene rubber can be carboxylated.
2.3.42
styrene-butadiene rubber (SBR)
range of general purpose synthetic rubbers or resins made by the copoly- merization of butadiene-1,3 and
styrene
NOTE When suitably compounded they form the basis for a wide range of solvent-borne adhesives. SBR is also
available as latices which are constituents of many adhesives. Styrene-butadiene rubber can be carboxylated.
2.3.43
styrene-butadiene-styrene copolymer rubber (SBSR)
range of synthetic rubbers made by copolymerization of styrene and butadiene consisting of styrene and
butadiene blocks arranged linearly
NOTE SBSR-copolymers are used for hot-melt and solvent based adhesives.
2.3.44
butyl rubber (IIR)
range of synthetic rubbers made by copolymerization of isobutylene and isoprene (2-methyl butadiene)
2.3.45
chloroprene rubber (CR); polychloroprene
range of synthetic rubbers based on polymerized 2-chloro-1,3-butadiene
NOTE Polychloroprene, particularly the strong and medium crystallizing grades, is widely used as a basis for solvent
and contact adhesives which are both applied by industries (e.g. footwear, furniture, construction, car) and by end users.
Polychloroprene is also available as lattices for dispersion adhesives.
2.3.46
polyisocyanate
product having two or more isocyanate groups in its molecule
NOTE Polyisocyanates are used:
 modified with polyester and/or polyether polyols as a moisture curing adhesive;
 with polyester and/or polyether polyols for high solids or solvent-free reaction adhesives;
 as a crosslinking agent for solvent and dispersion adhesives;
 as an adhesion promoter;
 as a primer.
2.3.47
polyurethane
polymer from reaction of a polyisocyanate and a polyol, in which the repeating linkage in the chain is
urethane -NH-CO-O-
NOTE Different polyurethane products are used for adhesives:
 hydroxyl polyurethanes for solvent-borne adhesives;
 polyurethane dispersions for water-borne adhesives;
 hydroxyl polyurethanes (unreactive) and isocyanato polyurethanes (reactive) for hot-melt adhesives;
 polyester and/or polyether polyols and high-solid and/or solvent-free polyisocyanates for reaction adhesives.
2.3.48
epoxide resin; epoxy resin
synthetic resin containing epoxide groups
NOTE This is a class of thermosetting resins that can be used in adhesives for structural purposes. Epoxide resins
can be crosslinked with stoichoimetric co-reactants such as primary or secondary Polyamines or anhydrides or by the use
of catalysts such as tertiary amines or borontrifluoride.
2.3.49
polyester
polymer in which the repeating linkage in the chain is -CO-O-
NOTE The resulting polyester can be saturated or unsaturated depending on the polycarboxylic acid used.
"Saturated polyesters" are used:
 as hot-melt adhesives;
 in conjunction with polyisocyanates for two-part polyurethane reaction adhesives. "Unsaturated polyesters" are used
combined with a liquid unsaturated monomer (e.g. styrene) as a basis for two-part reaction adhesives that require a
catalyst system.
2.3.50
polyamide (PA)
polymer in which the repeating linkage in the chain is -NH-CO-
NOTE There are "unreactive" and "reactive" types of polyamides. The former are made from dimer acids and
diamines and are solids used as hot-melt adhesives. The latter are usually made from blends of dimer acids and
monofunctional fatty acids condensed with polyamines and contain free amino groups. They are usually liquids and are
used in two-part adhesives. They are referred to as "poly(amino)amides".
2.3.51
amino resin
thermosetting resin made by polycondensation of a compound containing amino groups such as urea or
melamine with an aldehyde, such as formaldehyde, or an aldehyde-yielding material
NOTE Urea-formaldehyde (UF) and "melamine-formaldehyde" (MF) resins are of main significance in the adhesive
field.
2.3.52
phenolic resin (PF)
class of resins made by the polycondensation of phenol, its homologues and/or derivatives, with aldehydes or
ketones
NOTE 1 Phenols mainly used are:
 phenol, cresol, xylenol, butyl- and octyl-phenol, resorcinol and cashew nut liquid (from "Anacordia occidentale") which
consists mainly of substituted phenols. Mixtures of these phenols are as well used as mixtures of aldehydes like
formaldehyde or furfuraldehyde for the manufacture of these resins.
 "Lignin", a major constituent of wood obtained as a by-product of chemical pulping has a phenol-like chemical
comosition and is usually used in combination with PF resins as a phenol substitute.
 Condensed "tannins" obtained from the bark of several species of trees have a phenol-like composition and are
generally used in combination with PF resins.
NOTE 2 Depending on the condensation conditions a resol or novolak can be obtained:
 A "resol" is the result of reacting phenols and aldehydes normally under alkaline conditions with aldehyde in molar
excess. The molecules contain reactive methylol groups which will condense together on the application of heat.
 A "novolak" is the result of reacting phenols and aldehydes normally under acid conditions with phenols in molar
excess. The molecules do not contain reactive methylol groups and cannot condense on the application of heat
without the addition of hardening agents.
NOTE 3 Phenolic and similar based resins (e.g. resorcinolic resins) are used for bonding wood, glass and mineral
fibers, and also as tackifiers for solvent-borne adhesives.
2.3.53
furane resin
thermosetting resin in which the furan ring is an integral part of the polymer obtained by condensation of
furfurylalcohol or co-condensation of furfurylalcohol or furfurylaldehyde with other compounds such as
formaldehyde, phenol, urea and/or acetone
2.3.54
polysulphide
polymer containing disulphide -(-S-S)- linkages together with repeating polyether units usually terminated by
thiol or hydroxyl groups
2.3.55
silicone polymer (SI)
polymer in which the molecules consist of main chains of alternate silicon and oxygene atoms with side
groups containing carbon
2.4 Adhesive properties
2.4.1
density
mass of a unit volume
2.4.2
apparent density
mass divided by the volume of a sample material, including both perm
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