| 摘要 |
Hot melt adhesives especially suited for use in the perfect binding of books are prepared from (1) 15-30% of a block polymer having the general configuration A-B-A wherein A is a non-elastomeric polymer block derived from the moieties of a monovinyl aromatic hydrocarbon radical and B is an elastomeric polymer block derived from the moieties of a conjugated diene monomer; (2) 5-10% of an ethylene vinyl acetate copolymer containing 17 to 42% vinyl acetate; wherein the ratio of the block polymer to the ethylene vinyl acetate copolymer is within the range of 1.75:1 to 6:1; (3) 25-40% of at least one rosin ester tackifier selected from the group consisting of glycerol and pentaerythritol esters of natural and modified rosins, (4) 25-35% of a wax diluent which is solid at room temperature; and (5) 0.5 to 3% of at least one stabilizer. such composition being characterized by an ability to form a film exhibiting Instron yield strengths of 100-250 psi. and a low temperature flexibility of less than 10 DEG F.; such composition having a melt viscosity of 3,000 to 30,000 cps. at 350 DEG F., and being capable of setting up in less than 30 seconds and, when applied to roughened signature using perfect binding techniques yielding a book having an adhesion page pull on coated stock of at least 10 pounds, preferably at least 15 pounds, per page (73/8 to 71/2'' long). In addition to the adhesive described above, the present invention also discloses a method for binding books containing a plurality of sheets including at least some coated stock by means of the perfect binding method without the use of a primer using the novel adhesive of the present invention.
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