Tackifier
Encyclopedia
Tackifiers are chemical compounds used in formulating adhesive
s to increase the tack
, the stickiness of the surface of the adhesive. They are usually low-molecular weight compounds with high glass transition temperature. At low strain rate, they provide higher stress compliance, and become stiffer at higher strain rates.
Tackifiers tend to have low molecular weight, and glass transition and softening temperature above room temperature, providing them with suitable viscoelastic properties. Tackifiers frequently present most of both weight percentage and cost of hot melt adhesives and pressure sensitive adhesive
s. In hot melt adhesives they can comprise up to about 40% of total mass.
Tackifiers are usually resin
s (e.g. rosin
s and their derivates, terpene
s and modified terpenes, aliphatic, cycloaliphatic and aromatic resins (C5 aliphatic resins, C9 aromatic resins, and C5/C9 aliphatic/aromatic resins), hydrogenated hydrocarbon resins, and their mixtures, terpene-phenol resins (TPR, used often with ethylene-vinyl acetate
adhesives)).
Many pressure sensitive adhesive
s are a blend of rubbers (natural or synthetic) and a tackifying resin. Some acrylic adhesives also include an additional tackifier. Silicone rubber
based pressure sensitive adhesives require special tackifiers based on "MQ" silicate resins, composed of a monofunctional trimethyl silane ("M") reacted with quadrafunctional silicon tetrachloride
("Q").
Adhesive
An adhesive, or glue, is a mixture in a liquid or semi-liquid state that adheres or bonds items together. Adhesives may come from either natural or synthetic sources. The types of materials that can be bonded are vast but they are especially useful for bonding thin materials...
s to increase the tack
Tack
Tack may refer to:* A type of cut nail, used in upholstery, shoe making and saddle manufacture* Horse tack, harness and equipment to allow horse-back riding* Tack , quick, temporary stitching intended to be removed...
, the stickiness of the surface of the adhesive. They are usually low-molecular weight compounds with high glass transition temperature. At low strain rate, they provide higher stress compliance, and become stiffer at higher strain rates.
Tackifiers tend to have low molecular weight, and glass transition and softening temperature above room temperature, providing them with suitable viscoelastic properties. Tackifiers frequently present most of both weight percentage and cost of hot melt adhesives and pressure sensitive adhesive
Pressure sensitive adhesive
Pressure sensitive adhesive is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherend...
s. In hot melt adhesives they can comprise up to about 40% of total mass.
Tackifiers are usually resin
Resin
Resin in the most specific use of the term is a hydrocarbon secretion of many plants, particularly coniferous trees. Resins are valued for their chemical properties and associated uses, such as the production of varnishes, adhesives, and food glazing agents; as an important source of raw materials...
s (e.g. rosin
Rosin
.Rosin, also called colophony or Greek pitch , is a solid form of resin obtained from pines and some other plants, mostly conifers, produced by heating fresh liquid resin to vaporize the volatile liquid terpene components. It is semi-transparent and varies in color from yellow to black...
s and their derivates, terpene
Terpene
Terpenes are a large and diverse class of organic compounds, produced by a variety of plants, particularly conifers, though also by some insects such as termites or swallowtail butterflies, which emit terpenes from their osmeterium. They are often strong smelling and thus may have had a protective...
s and modified terpenes, aliphatic, cycloaliphatic and aromatic resins (C5 aliphatic resins, C9 aromatic resins, and C5/C9 aliphatic/aromatic resins), hydrogenated hydrocarbon resins, and their mixtures, terpene-phenol resins (TPR, used often with ethylene-vinyl acetate
Ethylene-vinyl acetate
Ethylene vinyl acetate is the copolymer of ethylene and vinyl acetate. The weight percent vinyl acetate usually varies from 10 to 40%, with the remainder being ethylene....
adhesives)).
Many pressure sensitive adhesive
Pressure sensitive adhesive
Pressure sensitive adhesive is adhesive which forms a bond when pressure is applied to marry the adhesive with the adherend...
s are a blend of rubbers (natural or synthetic) and a tackifying resin. Some acrylic adhesives also include an additional tackifier. Silicone rubber
Silicone rubber
Silicone rubber is an elastomer composed of silicone—itself a polymer—containing silicon together with carbon, hydrogen, and oxygen. Silicone rubbers are widely used in industry, and there are multiple formulations...
based pressure sensitive adhesives require special tackifiers based on "MQ" silicate resins, composed of a monofunctional trimethyl silane ("M") reacted with quadrafunctional silicon tetrachloride
Silicon tetrachloride
Silicon tetrachloride is the inorganic compound with the formula SiCl4. It is a colourless volatile liquid that fumes in air. It is used to produce high purity silicon and silica for commercial applications.-Preparation:...
("Q").