U.S. patent application number 09/766559 was filed with the patent office on 2001-09-27 for process for reducing sticky contaminants in stock systems containing waste paper and in coated broke.
Invention is credited to Hentzschel, Peter, Kohler, Achim, Reinhardt, Bernd.
Application Number | 20010023751 09/766559 |
Document ID | / |
Family ID | 4357100 |
Filed Date | 2001-09-27 |
United States Patent
Application |
20010023751 |
Kind Code |
A1 |
Kohler, Achim ; et
al. |
September 27, 2001 |
Process for reducing sticky contaminants in stock systems
containing waste paper and in coated broke
Abstract
The invention relates to a process for reducing sticky
contaminants in stock systems containing waste paper and in coated
broke, and their reuse in the manufacture of papers. In this
process, both polyvinyl alcohols and bentonite are added.
Inventors: |
Kohler, Achim; (Heilbronn,
DE) ; Hentzschel, Peter; (Oberursel, DE) ;
Reinhardt, Bernd; (Osnabruck, DE) |
Correspondence
Address: |
CLARIANT CORPORATION
4331 CHESAPEAKE DR
ATTN: INDUSTRIAL PROPERTY DEPT
CHARLOTTE
NC
28216
US
|
Family ID: |
4357100 |
Appl. No.: |
09/766559 |
Filed: |
January 19, 2001 |
Current U.S.
Class: |
162/147 ;
162/158; 162/168.1; 162/181.8; 162/191 |
Current CPC
Class: |
D21C 5/022 20130101;
D21C 9/08 20130101; Y02W 30/64 20150501; D21H 21/02 20130101 |
Class at
Publication: |
162/147 ;
162/158; 162/168.1; 162/181.8; 162/191 |
International
Class: |
D21H 021/02 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 19, 2000 |
CH |
2000 0099/00 |
Claims
1. Process for reducing sticky contaminants, in particular those
with a finely divided composition (microstickies) in the
preparation of stock systems containing waste paper and of coated
broke, characterized in that, after mechanical preparation has been
carried out and, if necessary, coarse sticky constituents
(macrostickies) have been separated, the stock system has added to
it at least one water-soluble organic polyol, in particular a
water-soluble organic polyvinyl alcohol or a mixture of various
water-soluble polyols, in particular of water-soluble organic
polyvinyl alcohols, and at least one bentonite or a mixture of
different bentonites and, if appropriate, further chemical
additives and filler.
2. Process according to claim 1, characterized in that the organic
polyvinyl alcohols used are water-soluble polymers with proportions
of vinyl alcohol or a copolymer of vinyl alcohol and vinyl acetate,
which contain hydrophobic groups and are hydrolyzed to more than
70% by weight, being used after the mechanical preparation in
proportions from 0.05 to 2% by weight, in particular from 0.1 to 1%
by weight, based on fibrous material, in combination with
bentonites with a high specific surface, preferably alkali modified
bentonites, in proportions from 1 to 10% by weight, based on
fibrous material.
3. Process according to claim 1, characterized in that the organic
polyvinyl alcohols used have a molecular weight from 1 000 to 250
000, preferably 9 000 to 150 000.
4. Process according to claim 1, characterized in that the prepared
stock mixture has added to it cationic fixing agents in proportions
from 0.05 to 1% by weight, based on fibrous material.
5. Process according to claim 1, characterized in that further
chemical additives and fillers are mixed in.
6. Paper which is produced by means of a secondary fibrous material
mixture prepared in accordance with claim 1.
Description
FIELD OF THE INVENTION
[0001] The invention relates to a process for reducing sticky
contaminants in stock systems containing waste paper and in coated
broke, and their reuse in the manufacture of papers.
BACKGROUND OF THE INVENTION
[0002] It is prior art to return paper waste from natural fibrous
materials for economically expedient reuse. For this purpose,
mechanical and chemical processes are often usually used together
for dispersion, removing printing ink (de-inking), bleaching,
cleaning (washing) and screening.
[0003] As a result of the increased input of mixed waste paper as a
source of raw material in papermaking, large quantities of solid or
water-soluble, sticky constituents are also carried into the paper
machine circuits. They constitute a significant cause of so-called
"stickies" and "white pitch" which, because of their hydrophobic
properties, are often deposited on hot and moving parts and in the
wires and felts of paper machines and can therefore lead to paper
web breaks.
[0004] "stickies" is understood to mean sticky deposits in the form
of organic complexes, which are formed from the waste paper by the
agglomeration of disruptive materials which interact with one
another. All sticky deposits which are introduced exclusively via
the raw materials are referred to as "primary stickies". If, on the
other hand, the formation of the sticky contaminants is brought
about only after reaction with additives, then these deposits are
referred to as "secondary stickies". The main source for sticky
contaminants are adhesives from paper conversion, but also
synthetic binders from paper finishing.
[0005] "white pitch" is a special case of "sticky" formation, which
is associated with the use of polyvinyl acetate and styrene
butadiene latices, for example from coated paper broke (Das Papier
(1998) 10 A, V 36 -V 41; Wochenblatt fur Papierfabrikation (1990)
8, 310-313).
[0006] The aforementioned "stickies" and "white pitch" are to be
viewed as disruptive materials in papermaking, which as far as
possible have to be "neutralized" in terms of their stickiness or
separated.
[0007] In order to ensure effective treatment of disruptive
materials, the size distribution of the disruptive materials to be
encountered is critical for the thermal, chemical and/or mechanical
processes to be used.
[0008] A rough distinction is drawn between macrostickies for
particle sizes above 150 .mu.m, which can largely be removed from
the stock circulation by means of the aforementioned separating
processes, and microstickies made of sticky contaminants between 1
.mu.m and 150 .mu.m
[0009] In most cases, microstickies do not cause any problems in
papermaking if they do not agglomerate. In addition, they are then
below the visibility limit.
[0010] In order to prevent re-agglomeration of the microstickies to
a large extent, various processes are known for the chemical
modification of the stickies remaining in the stock stream and
their absorption on carrier materials with a high specific surface
and on the fibrous material.
[0011] Here, the following procedures have been tried and tested in
practice, but lead only to partial success.
[0012] 1. Dispersion with the Aim of Changing the Charging of the
Stickies by Means of Anionic and Non-ionic Dispersants
[0013] By this means, colloidal, charged particles are formed which
counteract agglomeration and deposition. The wetting properties of
the dispersant are very important in this case, since the
"stickies" are generally hydrophobic.
[0014] 2. Reducing the Tackiness of the Stickies by
[0015] Fixing the highly anionic disruptive materials by means of
highly cationic fixing agents (fonning so-called polyelectrolyte
complexes; the reaction product is then attracted to the anionic
fibre),
[0016] Absorption on synthetic fibres, pigments with a high
specific surface (e.g. talc, modified clay, mica, smectite,
bentonite), often with subsequent flocculation by means of polymers
to bind together separable macroflocs,
[0017] Covering (masking) with non-ionogenic hydrophilic polymers
or anionic zirconium compounds, in particular of zirconium acetate
and ammonium zirconium carbonate.
[0018] Known highly cationic fixing agents are polyethylene imine
(PEI), polydiallyldimethyl-ammonium chloride (PDADMAC), polyvinyl
amine (PVAm), polyaluminium chloride (PAC), polyacrylamide (PAAM)
and so on. The range of action of fixing agents extends, depending
on the type and modification of the chemicals used, from about 1 nm
to 50 .mu.m particle size of the microstickies (Das Papier (1998)
10 A, V 36 -V 41).
[0019] Solids with a low surface energy exhibit a hydrophobic
behaviour and therefore have a high affinity with hydrophobic
substances, such as stickies. These absorption agents also include,
amongst others, the synthetic fibres polyester, polyamide and
polypropylene.
[0020] Further adsorption agents used are primarily various types
of talc with a specific surface modification and grain size
distribution which, because of their hydrophobic and organophilic
surface, are capable of depositing on sticky constituents and
carrying them out with the paper. Adhesive particles encapsulated
in this way show a lower tendency to deposition on hot machine
parts. Combating sticky deposits by means of talc has some
drawbacks, however. For example, the system is very sensitive to
shear. In addition, talc is difficult to retain and often leads to
blinding of the felts. Talc can have a detrimental effect on resin
sizing and stabilizes foam.
[0021] For partial overflocking, highly concentrated flocking
agents, such as aluminium sulphate, aluminate, acids and so on, are
used.
[0022] Known masking agents for stickies are, amongst others,
ethoxilated nonylphenols and ethoxilated dodecylphenols having at
least 9 mol ethylene oxide, whose use is limited to dosage rates of
10 ppm because of an extreme tendency to foaming (Wochenblatt fur
Papierfabrikation (1990) 8, 310 -313).
[0023] In addition, graft copolymers of polyalkylene oxide and
partially saponified vinylacetate (up to 15% saponification) with a
weight ratio of 1:0.2 to 1:10, are used as masking agents, if
appropriate in combination with other papermaking aids, it being
possible for the polyalkylene oxide to be polyethylene,
polypropylene or polybutylene oxide (EP 0571144 A1).
[0024] Likewise, alkoxylation products, which are obtained by
reacting alkylene oxides with C.sub.10-22 carbonic acid derivatives
and/or C.sub.10-22 carbonic acids, act as masking agents (DE 195 15
273 A1).
[0025] A hydrophilic polymer based on vinyl alcohol, which contains
some hydrophobic groups such as acetates, propionates, butyrates or
oleates and has molecular weights from 2 000 to 125 000 or more (EP
0220001 B1), is used under the commercial name BETZ DETAC.RTM.
(trademark of the BETZ company) to combat the stickiness of
hydrophobic stickies by means of covering them with a hydrophilic
film over a wide pH and temperature range. This partially
saponified polyvinyl alcohol (PVAL) is usually metered in the thick
stock area, in order to ensure an adequate reaction time of 20-30
min with the stock to be treated, given good and thorough mixing.
The necessary dosage rates to combat stickies successfully depend
on the type and quantity of the waste paper used. Any influence by
other aids is ruled out because of their non-ionic charge
(Wochenblatt fur Papierfabrikation (1990) 8, 310-313).
[0026] An excess of PVAL would have an extremely detrimental effect
on the papermaking process and on effluent loading, since it is not
needed to cover the sharply varying proportion of stickies,
depending on the selected dispersion conditions (shear intensity,
pH and temperature range, combination of aids).
[0027] The formation of foam and an increase in the disruptive
materials carried by the waste water (COD and BOD content) result.
An additional difficulty is the poor biodegradability of PVAL.
[0028] On the other hand, underdosing with PVAL would lead to
inadequate masking of all the sticky constituents.
[0029] In relation to the pulping of separated base paper broke,
the selective adsorption capability of alkali modified bentonites
with respect to various water-soluble polymers, in particular with
respect to PVAL, in effluent has been demonstrated (Wochenblatt fur
Papierfabrikation (1996) 4, 148-152).
[0030] Accordingly, 130 mg of dissolved PVAL is bound by 1 g of
bentonite (ratio about 1:7.5). Practical investigations on effluent
with different disruptive material loadings and types ultimately
led to the result that, in practice, for safety reasons, eight to
nine times the quantity of bentonite, based on the water-soluble
PVAL proportion in the effluent, is used. As a result, at least 90
% of the dissolved PVAL from the effluent could be absorped and
carried out with the paper. As a result of the combined use of
bentonite and cationic fixing agent, such as PAC and PEI, in the
preparation of broke, the content of dissolved hydrocolloids in the
effluent could be reduced still further.
[0031] This beneficial action of a combined use of alkali modified
bentonite and cationic fixing agent for the absorption of PVAL
dissolved in the effluent has until now been practised only in the
pulping of separated base paper broke surface-sized with PVAL and
CMC.
[0032] A use of the aforementioned combination in the dispersion of
waste paper and coated broke, in which partially saponified
polyvinyl alcohol is added as a masking agent for microstickies,
appears to be ruled out, since a very wide range of disruptive
material loadings and a multiplicity of sticky constituents of
varied chemical composition would lead to uncontrolled
interactions.
SUMMARY OF THE INVENTION
[0033] The object of the invention was, therefore, to use the
positive properties of partially saponified polyvinyl alcohols as a
chemical agent for masking sticky constituents (microstickies) more
effectively, from a process engineering point of view, for
papermaking which will be less susceptible to disruption and more
environmentally friendly with respect to protecting water
supplies.
[0034] Surprisingly, the expected disruptive interactions could
largely be avoided by selecting the correct dosing sequence of the
individual components and the correct dosing location, depending on
application.
[0035] For this purpose, it was necessary first of all for
partially saponified PVAL to be introduced in a certain excess at
that point in the process of preparing waste paper and coated broke
where either macrostickies had already been removed by known
separation processes and only microstickies were predominantly
still present in the stock system, or even no macrostickies could
still be formed.
[0036] The point of addition for masking sticky microstickies can
therefore be located in the thick stock and also in the thin stock
area, depending on the selected preparation and separation
technique.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0037] What is claimed is a process for reducing sticky
contaminants, in particular those with a finely divided composition
(microstickies) in the preparation of stock systems containing
waste paper and of coated broke, characterized in that, after
mechanical preparation has been carried out and, if necessary,
coarse sticky constituents (macrostickies) have been separated, the
stock system has added to it at least one water-soluble organic
polyol, in particular a water-soluble polyvinyl alcohol or a
mixture of various water-soluble organic polyols, in particular a
mixture of various water-soluble polyvinyl alcohols, and bentonite
and, if appropriate, further chemical additives and fillers.
[0038] The organic polyvinyl alcohols used are water-soluble
polymers with proportions of vinyl alcohol or a copolymer of vinyl
alcohol and vinyl acetate, which contain hydrophobic groups and are
hydrolyzed to more than 70% by weight.
[0039] The organic polyvinyl alcohols are used after the mechanical
preparation in proportions from 0.05 to 2% by weight, in particular
from 0.1 to 1.0% by weight, based on fibrous material, in
combination with bentonites with a high specific surface,
preferably alkali modified bentonites, in proportions from 1 to 10%
by weight, based on fibrous material.
[0040] The organic polyvinyl alcohols used have a molecular weight
from 1 000 to 250 000, preferably 90 000 to 150 000.
[0041] The polyol may also be a water-soluble organic copolymer
which contains repeating units of vinyl alcohol and of non-ionic
hydrophilic monomers, ionic hydrophilic monomers and/or hydrophobic
monomers, the water-soluble organic copolymers comprising at least
20 mol% vinyl alcohol.
[0042] Examples of hydrophobic monomers are vinyl acetate,
propylene oxide, methacrylate, methylethacrylate,
octadecylacrylate, n-octadecylacrylamide, styrene, allyl stearate,
vinyl stearate, ethene, propene, n-butene, isobutene, pentene,
dodecene, octadecene and vinyl ether higher than methyl.
[0043] Examples of non-ionic hydrophilic monomers are vinyl
pyrrolidone, ethylene oxide and acrylamide.
[0044] The copolymer can have random distribution of the monomer
units or various degrees of block formations and/or alternations in
the polymer.
[0045] Block formation means that in the copolymer there are
regions which are formed by only one of the monomers, while in the
case of alternation, a monomer of one sort is always bound to a
monomer of the other sort.
[0046] The polyvinyl alcohols may also be modified, for example by
cationic groups.
[0047] In a preferred process, the prepared stock mixture also has
added to it cationic fixing agents in proportions from 0.05 to 1%
by weight (commercially available), based on fibrous material.
[0048] In a likewise preferred process, further conventional
chemical additives (such as, inter alia, dry strengthening agents,
wet strengthening agents and sizing agents) and fillers 10 (inter
alia, clay, calcium carbonate and talc) are mixed in.
[0049] What is also claimed is paper which is produced by means of
a secondary fibrous material mixture prepared in accordance with
the process of the invention.
EXAMPLES
[0050] The process according to the invention, comprising a
combination of partially saponified polyvinyl alcohol, alkali
modified bentonite and cationic fixing agents, is explained by the
following exemplary embodiments:
[0051] Exemplary Embodiment 1
[0052] By means of a high-speed laboratory stirrer (10 000 rev/min)
small cut paper pieces of constant fibrous composition and with an
addition of different contact adhesives of about 10% was
disintegrated at a consistency of 4% for a period of 5 min until it
was free of specks (microstickies below the visibility limit of
about 150 .mu.m).
[0053] The stock mixture prepared in this way then had added to it,
in a different sequence, various hydrophilicization agents, in
particular partially saponified polyvinyl alcohols as masking
agents, pigments with a high specific surface, in particular
bentonites, as adsorption agents, and various cationic fixing
agents of different chemical composition. The amount added was 1%
by weight (commercially available) in the case of fixing and
masking agents and, respectively, 5% by weight (solids) in the case
of adsorption agents, based on fibrous material.
[0054] Following each addition of one of the abovementioned
products, attention is paid to adequate thorough mixing before any
possible addition of a further product. Following the addition of
partially saponified polyvinyl alcohols, attention is paid to an
action time of 30 min in accordance with the recommendation of the
chemical suppliers before a further product is added to the stock
mixture.
[0055] The preparation conditions, such as pH and temperature, can
be varied over a wide range.
[0056] Then, laboratory sheets are formed in accordance with the
ZELLCHEMING standard method and dried, and in addition filtrates
from the stock samples are taken in order to determine the chemical
oxygen demand (COD).
[0057] Since to date no method of determining microstickies below
150 .mu.m in stock systems exists, recourse must be made to COD
determination, although this permits only a statement about the
trend towards sticky loading (Wochenblatt fur Papierfabrikation
(1997) 9, 468-477).
[0058] Therefore, composite materials from the formed, moist paper
sheets are additionally prepared together with aluminium foil by
being compressed with one another within 30 seconds in a hot press
at 20 bar pressure and 130.degree. C. and later, following cooling
and intermediate storage under standard conditions (24 h at
23.degree. C./50% relative humidity), the forces needed to separate
the two layers, approximating to the FINAT method, can be
determined. The higher the separation force, the higher is the
residual stickiness of the microstickies. In addition, the
stickiness of any residues adhering to the laboratory stirrer, and
their elimination by means of a powerful water jet, are
assessed.
[0059] The results of some laboratory trials are presented in
Tables 1 to 6. The results were deliberately selected at a
dispersion temperature of 60.degree. C., since partially saponified
polyvinyl alcohols are only effective as a masking agent above
100.degree. F. (38.degree. C.).
[0060] If, for example, the additives already mentioned are added
as individual components to a fibrous stock mixture with an
addition of 10% adhesive of different composition, then in general
a decrease in the stickiness of the microstickies is found on the
basis of the separation force measurements (Tables 1, 3 and 5). In
this case, fixing agents can be just as effective as adsorption or
hydrophilicization agents (masking agents).
[0061] However, as expected, talc is generally less beneficial in
its effect than bentonite as an adsorption agent (Tables 1 and
3).
[0062] On the other hand, hydrophilicization agents based on
partially saponified polyvinyl alcohols belong in the group of
additives which bring about the lowest reduction in the COD value
in the filtrate, and to some extent even increase it. In this case,
the degree of saponification and further properties of the
polyvinyl alcohols used, such as molecular weight, viscosity and so
on, appear to play a part (Tables 1 and 5).
[0063] This points to the fact that polyvinyl alcohol is no longer
deposited on the microstickies but also strays into the effluent in
dissolved form.
[0064] A remedy is provided only by the combination of partially
saponified polyvinyl alcohol and alkali modified bentonite (Table
2, Variant A3+B2). A fixing agent which is additionally used can,
if necessary, reduce the COD value still further (Table 2, Variant
A3+B2+A1), but in the least favourable case, can also make the
separation force and COD values worse again (Table 2, Variant
A3+B2+B1). From this it is possible to derive the fact that,
depending on the stock and adhesive system used, the optimum fixing
agent in this combination of additives has to be found.
[0065] Using the combination according to the invention of
polyvinyl alcohol/bentonite (Table 2, Variant A3+B2), it is clear
that the best results with respect to the reduction of the
stickiness of microstickies can be achieved. If, on the other hand,
the adsorption agent bentonite (B2) is replaced by talc (A2), then
this combination (polyvinyl alcohol A3+talc A2) is less effective
by far if the separation force values are used as a basis (Table
2), or even disadvantageous in the case of a different adhesive
addition (rubber instead of acrylate adhesive, Table 6).
[0066] Combinations of adsorption agents (talc or bentonite) with
fixing agents were likewise not very effective with respect to
reducing the separation force (Table 4).
[0067] Exemplary Embodiment 2
[0068] A broke paper had about 5% (solids) of an acrylate contact
adhesive added to it, and this stock mixture was well and
thoroughly mixed under practical conditions in a technical centre
pulper for a period of about 45 min at a moderate consistency of 6%
and a temperature of about 60.degree. C. The pH of the stock
mixture was adjusted to about 6.
[0069] In the order specified, the following were then added to the
stock mixture as additives:
[0070] 1. partially saponified polyvinyl alcohol (1%)
[0071] 2. alkali modified bentonite (2.5% solids)
[0072] 3. cationic fixing agent (0.6%)
[0073] in each case a mixing period of 30 min (in the case of
polyvinyl alcohol) and, respectively 10 min being maintained before
the addition of the next component.
[0074] The COD content of originally about 320 mg O.sub.2/l in the
filtrate was reduced to below 150 mg O.sub.2/l by means of this
combination.
[0075] Residual stickiness of the microstickies in the formed paper
sheet, which could be demonstrated by dyeing with a special blue
dye, could no longer be demonstrated by means of separation force
measurement (initial value of the sample without additives was more
than 5 N).
[0076] This therefore confirms the positive results of the
combination of partially saponified polyvinyl
alcohol/bentonite/cationic fixing agent from the laboratory trial
(Exemplary embodiment 1).
[0077] This stock mixture, thus treated in accordance with the
invention, was used to produce new paper without any disruptive
deposits in the paper machine system (machine part, water
circulation).
1TABLE 1 Influence of additives on the reduction of the stickiness
of stickies (microstickies) ACRYLATE ADHESIVE I DISPERSION: pH = 7
at 60.degree. C. Addition as individual component
hydrophilicization agent Cationic fixing agent adsorption agent
(masking agent) no additive A1 B1 A2 B2 A3 B3 Separation force, N
6.17 3.66 3.98 3.53 3.91 4.49 3.34 COD, mg O.sub.2/1 185 69 100 116
123 162 134 Sticky residues many Removability poor Fixing agent: A1
Dicyan diamide B1 Methylol amide Adsorption agent: A2 Talc
(cationic) B2 Bentonite (alkali activated) Hydrophilicization agent
(masking agent): A3 partially saponified polyvinyl alcohol I (DETAC
.RTM.) B3 partially saponified polyvinyl alcohol II (RATIFIX .RTM.)
(Clariant trademark)
[0078]
2TABLE 2 Influence of the combination of additives on the reduction
of the stickiness of stickies (microstickies) ACRYLATE ADHESIVE I
Dispersion: pH = 7 at 60.degree. C. Addition as combination of
additives hydrophilicization hydrophilicization agent + Adsorption
agent + agent + adsorption agent + no fixing agent adsorption agent
fixing agent additive A2 + B1 B2 + B1 A3 + A2 A3 + B2 A3 + B2 + A1
A3 + B2 + B1 Separation force, N 6.17 6.78 6.92 5.28 3.01 3.30 4.37
COD,mg O.sub.2/I 185 268 243 121 116 39 248 Fixing agent: A1 Dicyan
diamide B1 Methylol amide Adsorption agent: A2 Talc (cationic) B2
Bentonite (alkali activated) Hydrophilicization agent (masking
agent): A3 partially saponified polyvinyl alcohol I (DETAC
.RTM.)
[0079]
3TABLE 3 Influence of additives on the reduction of the stickiness
of stickies (microstickies) ACRYLATE ADHESIVE II Dispersion: pH
<3 at 60.degree. C. Addition as individual component No Cationic
fixing agent adsorption agent additive C1 A2 B2 Separation force, N
4.28 3.29 3.71 3.80 COD, mg O.sub.2/l 112 110 88 165 Sticky
residues few Removability good Fixing agent: C1 POLYDADMAC .RTM.
Adsorption agent: A2 Talc (cationic) B2 Bentonite (alkali
activated)
[0080]
4TABLE 4 Influence of the combination of additives on the reduction
of the stickiness of stickies (microstickies) ACRYLATE ADHESIVE II
Dispersion: pH <3 at 60.degree. C. Addition as combination of
additives adsorption agent adsorption agent no A2 + fixing B2 +
fixing additive agent C1 agent C1 Separation force, N 4.29 4.36
4.28 COD, mg O.sub.2/l 112 82 46 Fixing agent: C1 POLYDADMAC .RTM.
Adsorption agent: A2 Talc (cationic) B2 Bentonite (alkali
activated)
[0081]
5TABLE 5 Influence of additives on the reduction of the stickiness
of stickies (microstickies) RUBBER ADHESIVE Dispersion: pH = 7 at
60.degree. C. Addition as individual component No adsorption
hydrophilicization agent additive agent A2 (masking agent) B3
Separation force, N 4.91 4.85 4.20 COD, mg O.sub.2/l 171 156 212
Sticky residues many Removability poor Adsorption agent: A2 Talc
(cationic) Hydrophilicization agent (masking agent): B3 partially
saponified polyvinyl alcohol II (RATIFIX .RTM.)
[0082]
6TABLE 6 Influence of the combination of additives on the reduction
of the stickiness of stickies (microstickies) RUBBER ADHESIVE
Dispersion: pH = 7 at 60.degree. C. Addition as combination of no
hydrophilicization agent (masking agent) additive A3 + adsorption
agent A2 Separation force, N 4.91 5.85 COD, mg O.sub.2/l 171 214
Adsorption agent: A2 Talc (cationic) Hydrophilicization agent
(masking agent): A3 partially saponified polyvinyl alcohol (DETAC
.RTM.)
* * * * *