Page 97 - Handbook of Surface Improvement and Modification

92 Tackifiers

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ing temperatures. Lower viscosity also helps the adhesive to “wet out,” or to uniformly
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coat the surface and penetrate the substrate. Any conventionally known tackifier, which
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is suitable for use in formulating hot-melt adhesives, may be used. A preferred tackifier
comprises a modified rosin (such as an ester modified rosin), an aromatic modified
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cycloaliphatic hydrocarbon resin, or polyterpene. The hot-melt adhesive composition
has properties at elevated temperatures or at low refrigerator and freezer temperatures that
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other conventional adhesives have been unsuccessful to reach.
A percutaneous absorption preparation for treatment of dementia that comprises
rivastigmine or its pharmaceutically acceptable salt as an active ingredient, a styrene-iso-
prene-styrene block copolymer, a tackifier resin ( selected from the group consisting of an
alicyclic hydrocarbon resin, an aliphatic hydrocarbon resin, a hydrogenated hydrocarbon
resin, a rosin-based resin, a terpene-based resin, and a polyester resin), and a plasticizer
(selected from a group consisting of petroleum oil, squalane, plant oil, synthetic oil, diba-
sic acid ester, liquid rubber, liquid fatty acid ester, diethylene glycol, polyethylene glycol,
glycol salicylate, propylene glycol, dipropylene glycol, triacetin, triethyl citrate, and cro-
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tamiton). Preferably, the tackifer may be either alicyclic hydrocarbon resins or aliphatic
hydrocarbon resins, or their mixtures (e.g. alicyclic hydrocarbon resins such as a styrene-
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α-methyl styrene resin (e.g., Kristalex F85)). The preparation allows a sufficient amount
of the active ingredient to penetrate into the skin to achieve an effective treatment of
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dementia.
Valve-through tire puncture sealant compositions includes anti-freezing agents and
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rigid particles. The aqueous solution with 0.1-10 wt% dissolved biomaterials and 0.1-10
wt% tackifier (sodium alginate) is mixed with anti-freezing agent, in which 0.01-5 wt%
rigid particles of biomaterials (chitosan) and other particles (kaolinite, silica, and colloidal
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silica) are suspended. Tackifier is added to increase the viscosity of the solution and to
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improve the tack of the rigid and flexible suspended solids to the punctured wall. The
sealant composition is environmentally friendly, has insignificant settling, and long shelf-
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life. The sealant is capable of sealing puncture formed by less than or equal to 6.35 mm
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spike for long duration, i.e., more than 30 hours.
Tackified pressure-sensitive adhesives and tapes comprise a copolymer based on an
acrylic backbone, with a glycidyl monomer, unsaturated carboxylic acid monomer, and a
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tackifier. The adhesive has dual cure (heat and aziridine) and has a combination of out-
standing peel adhesion on the low surface energy substrates, high temperature shear per-
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formance, excellent stress relieving properties, and excellent converting properties. The
selection of tackifying resin and its amount should be considered in formulation as well as
®
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the type of acrylic polymer being tackified. Some resins, such as Foral 85, are broadly
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compatible with acrylic compositions. Others, like Regalrez™ 6108, tackify a limited
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number of compositions. The type of tackifying resin and the amount employed is to be
compatible with the acrylic polymer which means that when the tackifier and copolymer
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are combined, the resulting combination should be transparent.
The polyamide films are widely used in packaging applications, due to their superior
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puncture resistance. They are used to make puncture-resistant bags for meat and other
food types, but the processes for making the bags typically involve high temperatures to
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seal the bags. A potential way of addressing the problem is to provide a heat seal layer
on polyamide via solution coating rather than using blown film or extrusion processes. 32