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Formulation frozen adhesives

In general, specific processes for formulating adhesives are proprietary with the adhesives manufacturer. However, some basic methods and considerations for formulating paste, film, and frozen adhesives are given here. [Pg.117]

Phenolic materials go back to the patents of Baekeland and are based upon the reaction of phenol and formaldehyde to yield a lower molecular weight resinous material that can be formulated with other resins and sometimes other curatives to yield a paste adhesive or a film adhesive. When phenol and formaldehyde are reacted in the presence of an acidic catalyst with an excess of phenol versus formaldehyde, they yield what are known as novolac resins. These materials are soluble in organic solvents and do not react further with themselves thus, they need to have a curative added. That curative is most often hexamethylene tetraamine. Another type of phenolic resin can be generated with an excess of formaldehyde and under basic conditions. These materials, known as resole phenolics, will react with themselves to yield a ftilly cured phenolic and thus must be stored frozen in order to limit this reaction. Thus, resole phenolics do not need an external CTOsslinker. Resole phenolics are widely used in the binding of paper products and the bonding of wood. Adhesives based upon these materials were brittle and could only be used to bond wood, where it is still widely used. A more widely usable adhesive was developed during World War II which modified the very brittle phenolic adhesive with poly(vinyl formal) resins. These materials were... [Pg.313]


See other pages where Formulation frozen adhesives is mentioned: [Pg.117]    [Pg.115]    [Pg.8503]    [Pg.8536]    [Pg.169]    [Pg.141]    [Pg.203]    [Pg.237]    [Pg.393]    [Pg.321]    [Pg.850]    [Pg.114]    [Pg.91]    [Pg.91]    [Pg.361]    [Pg.55]    [Pg.168]    [Pg.260]    [Pg.264]    [Pg.140]   
See also in sourсe #XX -- [ Pg.121 ]




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