1070-4272/05/7806-1031 + 2005 Pleiades Publishing, Inc.
Russian Journal of Applied Chemistry, Vol. 78, No. 6, 2005, pp. 1031!1033. Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 6, 2005,
Original Russian Text Copyright + 2005 by Smirnova, Vasil’eva, Persinen.
AND POLYMERIC MATERIALS
Based on Low-Molecular-Weight Carboxylated
Yu. A. Smirnova, I. V. Vasil’eva, and A. A. Persinen
St. Petersburg State Technological Institute, St. Petersburg, Russia
Radiant Technology Center, Limited Liability Company, St. Petersburg, Russia
Abstract-Effects of a series of additives on the initial sticking and autohesion dynamics of electron-beam-
cured adhesives for adhesive tapes, based on low-molecular-weight carboxylated butadiene-acrylonitrile
rubber, were examined.
Modification of pressure-sensitive adhesives (PSAs)
with telechelic butadiene-acrylonitrile rubbers was
reported in . It is also known that liquid butadiene-
acrylonitrile rubber with terminal carboxy groups
is rapidly cured by electron beam at room tempera-
ture in air to give a rubber-like material (oligomer
MW 1700; carboxy group content 3%).
In this study, we examined the possibility of syn-
thesis of electron beam-cured PSA based on domes-
tic carboxylated low-molecular-weight butadiene-ni-
trile rubbers SKN-10-1 and SKN-10-KTR [mean
MW 1500; functional groups (3%) are arranged in
the backbone or as terminal groups; acrylonitrile units
are arranged in microblocks, each consisting of sev-
eral units; butadiene units are connected essentially
at the 1,4-positions.
To optimize the formulations, we studied the ef-
fects of a series of organic and mineral components
on the radiation stability of the investigated formu-
lation, autohesion of electron beam-cured PSAs, and
The formulations were prepared by mixing the com-
ponents at room temperature. As a support material
we used a tape made of carbon-black-extended PVC.
The electron-beam curing of the composites applied
onto the PVC tape surface was carried out in air,
using an RTE-1V experimental setup  (electron
energy 500 keV; beam current 1 mA). The target ma-
terial was passed under the accelerator scan-horn at
a speed of 1 m min
The criteria for determination of the absorbed
dose optimal for polymer conversion were the lack
of a contact pattern of the tested layer on glass and
of traces of low-molecular-weight fractions. The ab-
sorbed dose was determined by film dosimetry, using
standard polycarbonate detectors with a phenazine dye
[PD(F)-150/500 dosimetric films]. The optical density
of the irradiated detectors was measured on an SF-46
spectrophotometer at 512 nm.
The adhesiveness of the resulting samples was
determined according to GOSTs (State Standards)
[3, 4]. As a measure of the adhesiveness we used
the time in which the sample was separated under
a fixed stress. The quality of the materials tested was
evaluated by comparison of their adhesiveness with
that of similar domestic commercial products meeting
the requirements of GOST , using the procedure
employed in this study (the thus obtained adhesive-
ness of the commercial products was 8 s).
By electron-beam treatment in air of PVC-sup-
ported straight SKN-10-1 elastomer, we obtained
a constant-adhesiveness pressure-sensitive adhesive
(absorbed dose 400 kGy; autohesion 11 s). On the sur-
face of PSA obtained by electron-beam curing of
SKN-10-KTR, we observed, even at an absorbed dose
of 600 kGy, a layer of the low-molecular-weight frac-
tion, which can be attributed to exudation of stabiliz-
ers. Therefore, the subsequent experiments were per-
formed with SKN-10-1 rubber.
Mineral additives were introduced into low-molec-
ular-weight rubber for the following reasons. It is
known that extenders are sensitizers for the over-
whelming majority of rubbers. They reduce the mac-