Note: Descriptions are shown in the official language in which they were submitted.
~~~~~r
II
INTRODUCTION
I
This invention relates to a process for controlling natural I.
pitch deposition obtained from the processing of various wood pulps i
which are then used to manufacture paper products. These natural
pitch depositions are detrimental to efficient operations of paper
i
mills. Pitch deposits on process equipment used in the paper i
making systems resulting in operation problems related to the
accumulation of pitch deposits on consistency regulators and other
instrumental probes used to monitor the process of manufacturing
paper from various types of pulp and paper furnishes.
In addition pitch deposits can form on screens and can reduce
throughput as well as upset the operation of the paper
manufacturing process. The deposition of natural pitch can occur
not only on the metal surfaces in the system but also on plastic
and synthetic surfaces such as machinery wires, felts, foils, UHLE~
boxes, and head box com onents. These itch de
P p posits may also
break off resulting in spots and defects in the final paper product)
which thereby decreases the paper quality.
PRIOR APPROACHES TO CONTROLLING PITCH
Surfactants, anionic polymers and co-polymers of anionic
monomers and hydrophobia monomers have been used extensively to
prevent pitch deposition. For example, in the text "Pulp and
Paper" by ,Tames B. Casey, volume II, second edition, pages
1096-7, these types of polymers are described for this purpose.
In addition, bentonite, talc, diatomaceous earth, silica,
starch, animal glue, gelatin and alum have also been used to reduce
pitch deposits. U.S. Patent 3,081,219, Drennen et al., discloses.
the use of polymeric N-vinyl lactam to control pitch in making
paper from sulfite pulps.
z
~1~~~3gd
In addition the following patents have disclosed the use of
various kinds of chemicals both polymeric and nonpolymeric for .
pitch control. , '
U.S. Patent 3,154,466, Nothum
a U.S. Patent 3,582,461, Lipowski et al., '
~JU.S. Patent 3,619,351, Kolosh
U.S. Patent 3,748,220, Gard
U.S. Patent 3,992,249, Farley
i
U.S. Patent 4,184,912, Payton
i
~iU.S. Patent 4,190,491, Drennen et al.,
~~U.S. Patent 4,253,912, Becker et al.,
~ U.S. Patent 4,871,424, Dreisbach, et al.,
~U.S. Patent 4,765,867, Dreisbach et al.,
U.S. Patent 4,744,865, Dreisback et al., j
-:Canadian Patent 1,194,254, Molnar
~'Canadian Patent 1,150,914, Molnar I
i
I
U.S. Patent 4,313,790, Pelton et al.,
All of the above patents disclose certain processes ands
formulations, including cationic polymers and specifically, fori
example, in Canadian 1,194,254, certain cationic polymers formed]
by polymerization of diallyl dimethyl ammonium chloride, which
polymers are useful for pitch control. i
In addition, an article appearin in a
g publication by they
Institute of Paper Scienee and Technology in Atlanta, Georgia,
authored by Weigel, et al., and entitled "Resin Deposits and Their
Control in Papermaking" and translated from Papier 40(10A): V52-62
i
(October 1986), also described pitch deposits and their control in t
various paper mills. '
I
An article, "Unusual Applications of Dual Polymer Systems" by~l
Dykstra, et al., published in the 1987 TAPPI Advanced Topics in Wet ;
3
CA 02040337 2002-03-19
66530-492 ''
End Chemistry Seminar, speaks of the use of anionic polymers
in combination with charged condensation polymers having
cationic charge for use in pitch control.
Another article entitled "Pitch and Stickies
Control in Pulp and Paper Mills" by Pamela J. Allison
published in Paper Southern Africa, volume 8, No. 3, 1988,
talks of pitch and stickier deposits and techniques for
their control. Another paper by Dykstra et al., entitled,
"A New Method for Measuring Depositable Pitch and Stickies
and Evaluating Control Agents", published in 1988 TAPPI
Papermakers Conference Proceedings, page 327, also talks of
pitch and stickier control. This paper also talks of dual
polymer treatment.
Finally in the June, 1988, Tappi Journal, on page
195, an article by Hassler, entitled, "Pitch Deposition in
Papermaking and the Function of Pitch-control Agents,"
speaks of various pitch control agents and techniques to
assist in pitch deposition and control.
In none of the references, including the specific
Canadian patent to Molnar referring to the use of a
homopolymer of DADMAC, i.e., diallyl dimethyl ammonium
chloride, is there any mention of the use of ampholytic
polymers containing diallyl dimethyl ammonium halide
monomers.
It is an object of this invention to disclose an
improved process of pitch control which process uses as a
pitch control agent, water soluble co-polymers and
terpolymers which are formed by polymerization of diallyl
dimethyl ammonium salts with acrylic acid or methacrylic
4
i
CA 02040337 2002-03-19
66530-492 '~ °,
acid or their salts, and optionally using various alkyl
acrylate esters or hydroxy substituted alkyl esters of
acrylic acid or methacrylic acid.
4a
Another object of the invention is to eliminate or minimize
the effect of natural pitch deposits in the manufacture of paper ,
by adding to a pitch contaminated paper furnish prior to sheet
formation, an improved pitch control agent which agent is a co-
polymer or terpolymer containing diallyl dimethyl ammonium salts,
acrylic acid or methacrylic acid and its salts, and, optionally, i
alkyl acrylate or hydroxy alkyl acrylates.
Another abject of the invention is to provide a specific co- I
polymer and/or terpolymer which is useful as a pitch control agent
which polymer has a molecular weight ranging from about 10,000 to
I
about 1,000,000 and contains from 75 - 95 mole per cent of dia11y1
dimethyl ammonium chloride; contains from about 2 to about 25 mole
i
per cent of acrylic acid, methyacrylic acid, or their salts, or I
mixtures thereof; and from about 0 to about 10 mole per cent of an
alkyl acrylate or a hydroxy alkyl acrylate or mixtures thereof.
THE INVENTION
We have determined that an improved process for controlling
natural pitch deposition onto paper machine surfaces and into the
i
paper sheet can be demonstrated, which process includes the
addition of an effective pitch deposit controlling amount of pitch)
control agents to the pitch contaminated paper furnish prior to
paper sheet formulation, the improvement comprising using as ai
pitch control agent a water soluble co-polymer comprising ai
combination of monomers chosen from the group consisting of diallyl~
dimethyl ammonium salts, (meth)acrylic acids and salts thereof,
and alkyl or hydroxyalkyl acrylates, thereby forming polymers
having the structure:
66530-492 _~
~~~J~~
R R
I
CH CII CH C CH2.- C
2 (+) 2 2 I
_ j = O O = C
X( )
R R 0 0
I
(R')
a b ( d
(Y) a
wherein R is individually chosen, at each occurrence, from
hydrogen, methyl groups, and ethyl groups, preferably if R is
covalently bonded to a nitrogen, R is chosen, at each occurrence,
only from methyl groups and ethyl groups; and M is chosen, at
each occurrence, from hydrogen, alkali metal cations, equivalent
amounts of alkaline earth metal cations, ammonium canons,
protonated amine or quaternary ammonium cations and mixtures
thereof; and R' is a multivalent hydrocarbonaceous bridging
group containing from 1 - 24 carbon atoms and chosen from
linear and branched alkyl groups, cyclic groups, aromatic groups,
i
alkar 1 and aralk 1
Y y groups, and mixtures thereof, preferably R
is a multivalent hydrocarbonaceous linear or branched alkyl
group containing from 1 - 24 carbon atoms; and X is an anion
present in electroneutral amounts relative to positively
charged nitrogen in the polymer backbone; Y is chosen from -H,
-OH, and mixtures thereof; wherein 'the sum of a+b+d is
sufficient to provide for a weight average molecular weight
ranging between about 10,000 and about 1,000,000; a is from 0
to 6; and the following relationships exist:
a:b is at least 3:1
a:(b + d) is at least 75:25, and
d:(a + b) ranges from 0 to 1:9, and further
d, but not a or b, can be zero.
In one embodiment the pitch control agent is a
terpolymer having a weight average molecular weight ranging
6
~~~~~"~'
66530-492
between about 50,000 to about 500,000, and R, when attached to
nitrogen in the polymer structure is -CH3, and when attached to
carbon in the polymer structure is from the group H, CH3, or
mixtures thereof; R' is a linear or branched alkylene group
having from 1 to 16 atoms; and a is from 0 to 4; and the follow-
ing ratios exist:
a:b is at least 4:1,
a:(b + d) is at least 80:20, and
d:(a + b) ranges from 0 to 1:9, and the effective
pitch deposit controlling amount of the copolymer ranges from
about 0.01 to about 2.0 pounds active copolymer per ton of dry
fiber.
Preferably R is chosen at each occurrence from H and
CH3; R' is linear or branched alkyl group having from 1 to about
14 carbon atoms; X is C1; M is H, Na, K, Li, NH4, or mixture
thereof; Y is from H and -OH, and mixtures thereof; a is from 0
to 2; and the sum a + b + d is sufficient to obtain a weight
average molecular weight from about 50,000 to 500,000; d, but
neither a or b can be zero; and the ratio a:b is at least 4:1;
and the ratio, d:(a + b) never exceeds 1:9.
THE POLYMER STRUCTURE
The polymer structure is as that described above. In
this structure each monomer unit is essentially randomly
distributed
6a
along the polymer chain and the polymer is ampholytic in nature,
i.e. it can carry both a positive and a negative charge.
In addition the polymer optionally contains from 0 to about
mole per cent of a monomer which is oleophillic in character.
I
This oleophillic monomer is preferably an ester or hydroxyester of j
acrylic acid, methacrylic acid, ethacrylic acid, or mixture
I
thereof.
The cationic character of the polymers described above are
provided by inclusion of from about 75 to about 95 mole per cent
of diallyl dimethyl ammonium salts. These salts may be chlorides,
bromides, iodides, sulfates, nitrates, phosphates, and the like.
Preferably, these quaternary di-vinyllic salts are in the form of
I
diallyl dimethyl ammonium chloride (known in abbreviation as
I
DADMAC). The diallyl, dimethyl ammonium chloride (DADMAC) monomer
is contained in the polymer at from about 75 to about 95 mole per
cent, preferably from about 80 to about 90 mole per cent, and most
preferably between 85 to about 90 mole per cent. This provides for
an overwhelming positive charge on the backbone polymer.
i
However, it has been demonstrated that improvements in the use
of these materials as pitch control agents are provided by the
i
inclusion in the backbone of the polymers described above of from i
i
2 to about 25 mole per cent of an anionic monomer unit. The I
preferred anionic monomer is chosen from acrylic acid, methacrylic '
acid, ethacrylic acid, and their common salts, or mixtures thereof.
i
Preferably the salts are in the form of alkali metal salts, i
equivalent amounts of alkaline earth metal salts, or salts of
ammonium rations, quaternary amine rations, or protonated amine I
i
rations. Most preferably the anionic monomer is acrylic acid, or I
methacrylic acid, or mixtures thereof, used either as the free acid I
or as the sodium, potassium, and/or ammonium salts. Of course any ~
mixtures of the salts are also included in the concept of using
7
~~~c.~~~
these anionic monomer units and incorporating them in the monomer
structures above. These anionic monomers can be represented by the
term (meth)acrylic acid, but this term is used herein to represent
any vinylic acid, or vinylic acid salt having the structure:
R 0
CHZ = C - C - OM
I where R is H, CH3, CZHS, and mixtures therof; and M is as
defined above.
As above, the polymer can be improved by the incorporation,
optionally, of certain oleophillic monomers such as (meth) acrylic
acid esters, or (meth)acrylic acid hydroxy esters. These compounds
provide some oleophillic character to the polymer and can assist
in accumulating and dispersing pitch particles and attaching these
pitch particles to cellulosic fibers so they do not accumulate
disadvantageously on paper machine surfaces or cause difficulties
otherwise in the manufacture of paper. These vinylic acid esters
and vinylic acid hydroxy esters are primarily those materials
chosen from acrylic acid esters, methacrylic acid esters, or
ethacrylic acid esters. By the term acrylic acid ester,
methacrylic acid ester, or ethacrylic acid ester we mean to also
include the hydroxy esters that contain one or more hydroxyl groups
on the alkyl unit attached to the ester oxygen.
The polymer that is preferred is a polymer that has a
molecular weight ranging from about 10,000 to about 1,000,000 and
most preferably has a molecular weight ranging from about 50,000 ;
to about 500,000. These molecular oreights are weight average
molecular weights. The most preferred polymer contains from about ~
80 to about 90 mole per cent of diallyl dimethyl ammonium chloride,
I
from about 5 to about 20 mole per cent of acrylic acid or i
methacrylic acid or mixtures thereof, (or salts thereof) and from
I
8 j
~i
about 0 to about 10 mole per cent of acrylic acid esters chosei
from the group consisting of hydroxy alkyl acrylates and alley:
acrylates, or mixtures thereof, where the alkyl group of the ester
I
functionality has from about 1 to about 24 carbon atoms, preferably
from about 2 to about 14 carbon atoms.
The ampholytic polymers of this invention do not necessarily
have to contain the (meth)acrylate esters or hydroxy alkyl (meth)
acrylate esters, but can be formed merely as co-polymers of diallyl
il dimethyl ammonium chloride (or other salt) and either acrylic acid,
methacrylic acid, ethacrylic acid, their salts, or mixtures
thereof. When co-polymers are used, it is preferred that DADMAC
is present between about 80 to about 95 mole per cent and the
anionic (meth)acrylic acid units are present at between about 5 to
about 20 mole per cent. Most preferably these co-polymers contains
about 80 to 90 mole per cent DADMAC and from about 10 to about 20
mole per cent (meth)acrylic acid, or its salts.
DOSAGES
Typically, dosages of products containing the pitch control
agents described above normally range from about 0.05 to about 20
pounds of formulated product per ton of paper product, on a dry
fiber basis. The pitch control agents normally are provided as
liquid dispersions or solutions of the polymers described in water
which products normally range from about 1 to about 40 weight per
cent active polymer. The polymer may also be provided as a water-
in-oil latex emulsion containing a dispersed aqueous phase in which
the polymer described above has been dissolved. This emulsion
normally also contains a controlled HLB surfactant system such that
when the water-in-oil emulsion is added to the paper making system,
inversion of phases occurs, and the polymer is rapidly dissolved
and dispersed in the aqueous paper making media. When the product
is supplied as a water-in-oil emulsion, the polymer content of the
9
66530-492
emulsion product can range from about 5 to about 55 weight per-
cent of the product. On an active polymer basis, the polymer
dosage for the polymers of this invention, and described above,
normally ranges from about 0.05 to about 2.0 pounds, preferably
1.5 pounds, per ton, on the basis of active polymer per 'ton of
dry fiber. To further exemplify and demonstrate our invention
the following examples are provided:
EXAMPLES
Laboratory trials of products meeting the descriptions
provided above were tested by the following procedure:
Example 1. Approximately 7,000 ml of a hardwood
kraft paper stock was prepared. This hardwood kraft stock
contained 2.27 weight percent fiber. This paper stock material
was diluted with water until it contained approximately 1.5
weight percent hardwood kraft stock fiber. The pH of this
stock was adjusted to about 10.6 with sodium hydroxide solution.
Approximately 100 ml of a 1 percent dispersion of a laboratory
pitch mixture was added to 700 ml of the 1.5 percent hardwood
kraft stock. The pH dropped to a pH of approximately 7.4-7.5.
To this pitch containing slurry of hardwood kraft fibers was
added 5 ml of a 0.5 molar calcium chloride dihydrate solution.
This mixture was gently stirred and 'the pH checked. The pII had
dropped to approximately 6.5. The pH of this test preferably
ranges somewhere between 5.5 and 7.0 during the testing sequence
for pitch deposition control.
The mixture of hardwood kraft stock, which mixture
contains synthetic pitch dispersion and calcium chloride as
described above is then poured into a laboratory blender. To
this slurry is added a preweighed poly tetrafluoro ethylene
plastic (PTFE) coupon which acts as a surface on which pitch is
accumulated. This PTFE coupon is added to the pitch
66530-492
contaminated hardwood kraft stock in the blender. The blender
used had 14 buttons controlling agitation blade speed. After
addition of the preweighed PTFE plastic
10a
I coupon, button number 4 is pushed and the stock is agitated for
three minutes. Other blender speeds are also operable. A pitch
I
deposit is obtained on the PTFE coupon, and after the coupon is t
removed, rinsed with distilled water from a wash bottle and dried i
in air, the coupon is then weighed. Drying time can range from
about 4 hours to about 24 hours. The amount of deposited pitch is
calculated by the difference from the original weight of the
coupon.
By using this technique for each test sample, the following
results were obtained.
11
TABLE I
Pitch Deposition Test
Inhibition of Pitch Deposition by
Polymers #1, and Polymer #3
Treatment Dosagre llbL tong Pitch Deposit Percent Decrease in
~.ctives Product Weight (ma) Pitch Debosit
Basis Basis Weight*
Control-1 0 0 290 -
Polymer #1 0.1 0.5 10 97
Polymer #3 0.1 0.5 g g7
I
Control-2 0 0 2gg __
Polymer #1 0.2 1.0 5 g8
Polymer #3 0.2 1,0 2- 99
Control°3 0 0 309 --
Polymer #1 0.5 2.5 3 99
Polymer #3 0.5 2.5 2 g9
Average control (untreated) pitch deposit weight = 296 mg
1 standard deviation = 12 mg
* Percent decrease in
pitch deposit weight = weight (control) - weight (treated) x 100 ',
weight (control) '
Polymer #1 polyDADMAC; MW - 150,000, 20% polymer solids
6.19 meq charge/g polymer
Polymer #3 polyampholyte coagulant; 20% polymer solids
DADMAC:Acrylate:Hydroxypropylacrylate
terpolymer
87:10:3 mole ratio
4.92 meq charge/g polymer (pH >8.0)
5.57 meq charge/g polymer (pH <4.5)
12
~~~3~~~
Example II. In addition, various tests were also performed
on a trial and experimental basis, on a machine chest stock
obtained from an active producing paper mill. The pH of the
machine chest stock was measured at 7.95 and samples of this stock
were treated in the laboratory with a homopolymer of diallyl
dimethyl ammonium chloride, as taught by Molnar, and was
simultaneously treated with the polymers of this invention.
Results are shown in Table II.
13
TABLE II
Reduction in Colloidal Pitch and Anionic "Trash" Content
of Machine Chest Stock from
a South eastern U.S. paper mill
Product Treatment Dosaae Percent Percent
(lb/ton) Transmittance Decrease
TU ~n Filtrate
I
Turbidity*
Control 0 44 -
Polymer #1 3.1 44 0
Polymer #1 6.2 54 23
Polymer #1 9 3 69 57
Polymer #2 3.1
44 0
Polymer #2 6.2 4g g
Polymer #2 9 3 62 41
Polymer #3 3.4 46 4
Polymer #3 6.8 69 57
Polymer #3 10 2 84 91
* Percent Reduction in
Filtrate Turbidity -
turbidity (treated) - turbidity (control) x 100
turbidity (control)
Polymer #1 = polyDADMAC homopolymer
Polymer #2 = a polyDADMAC solution polymer (different manufacturer)
Polymer #3 = Ampholyte polymer of invention
87 mole % DADMAC
l0 mole % acrylic acid (Na salt)
3 mole % hydroxypropyl acrylate
14
Success in Table II is measured by the percent decrease in
filtrate turbidity which is a measure of the amount of pitch which
has been suspended and attached to the fiber so that it does not
contribute to filtrate turbidity.
In addition to the Polymer #3 described above which polymer
is a polyampholyte containing DADMAC/acrylic acid, salts, and
hydroxypropylacrylate in a terpolymer, as described above, the
following data is also presented which describes other co-polymers
and terpolymers which fall within the claims of our invention and
the use of these experimental polymers for pitch deposition
control.
Examples III. (A - L)
The following test polymers were treated in the laboratory
using the procedures set forth in Example I, except that a modified
synthetic laboratory pitch was used.
TABLE II I
other ampholyte polymers
Polymer Monomer Type & Mole Ratio Intrinsic
*% Solids
Viscosity
dl dl
1/a)
Polymer 1 DADMAC (100%) 20 0.63
poly
Ampholyte (A) DADMAC:AA:HPA 20 1.08
(87:10:3)
poly DADMAC:AA (90:10) 20 0.92
Ampholyte (B)
I poly DADMAC:AA (95:5) 22.6 0.93
Ampholyte (C)
poly DADMAC:AA (85:15) 23.3 0.80
Ampholyte (D)
poly DADMAC:AA (80:20) 23 0.72
Ampholyte (E)
poly DADMAC:MAA (98:2) 21 0.74
Ampholyte (F)
poly DADMAC:MAA (95:5) 22.8 0.70
Ampholyte (G)
poly DADMAC:MAA (85:15) 22.5 0.37
Ampholyte (H)
poly DADMAC:2-EHA (97:3) 21.9 0.86
Ampholyte (J)
poly DADMAC:2-EHA (95:5) 22.5 0.74
Ampholyte (K)
DADMAC
copolymer (L) DADMAC:a-MS (97:3) 13.9 0.21
*DADMAC = diallyl dimethyl ammoniumchloride
AA - acrylic acid
MAA = methacylic acid
2-EHA = 2-ethylhexyl acrylate
a-MS -. alpha-methylstyrene
HPA = hydroxypropylacrylate
16
I~
The results of the testing of the polymers described in Table !
III are set forth below:
17 'i
TABLE IV
i
Pitch Deposition
PolyDADMAC Versus Polyampholytes A - K and
DADMAC copolymer L i
Treatment Dosage (lb/ton~ Pitch Deposit Percent Decrease in
Actives Product Weiaht ~(ma) Pitch Deposit Weiaht* ~,
Basis Basis t
Control-1 0 0 78 -
i
p-DADMAC 0.01 0.05 64 12
p-Amphol. A 0.01 0.05 71 3
p-Amphol. B 0.01 0.05 63 14
p-Amphol. C 0.01 0.04 68 7
i
p-Amphol. D 0.01 0.04 66 10
p-Amphol. E 0.01 0.04 70 4
I
Control-2 0 0 73 --
p-DADMAC 0.05 0.25 42 42
p-Amphol. A 0.05 0.25 47 36
p-Amphol. B 0.05 0.25 19 74 I
p-Amphol. C 0.05 0.22 31 58
p-Amphol. D 0.05 0.22 24 67
p-Amphol. E 0.05 0.22 39 47
Control-3 0 0 57 --
p-DADMAC 0.10 0.50 18 75
p-Amphol. A 0.10 0.50 20 73
p-Amphol. B 0.10 0.50 11 85 .,
p-Amphol. C 0.10 0.44 12 84
p-Amphol. D 0.10 0.43 20 73
I
p-Amphol. E 0.10 0.44 17 77 ~~
Control-4 0 0 85 --
i
18
y
TAE3LE IV (coast. )
Pitch Deposition
PolyDADMAC Versus Polyampholytes A - K and
DADMAC copolymer L
Treatment Dosage (lb/ton) Pitch Deposit Percent Decrease in j
Actives Product Weiahr~ mq) Pitch Deposit Weiqht~*
Bas's Basis
Control-1 0 0 72 -- i
p-DADMAC 0.01 0.05 73 9
p-Amphol.F 0.01 0.05 72 10
I
p-Amphol.G 0.01 0.04 77 38
p-Amphol.H 0.01 0.04 80 0
p-Amphol.J 0.01 0.05 70 13
p-Amphol.K 0.01 0.04 73 9
DAD/Cop. 0.01 0.07 68 15 i
L
Control-2 0 0 89 - i
1
p-DADMAC 0.05 0.25 60 25 j
p-Amphol.F 0.05 0.24 24 70
p-Amphol.G 0.05 0.22 35 56
I
p-Amphol.H 0.05 0.22 53 34 j
p-Amphol.J 0.05 0.23 34 58
p-Amphol.K 0.05 0.22 35 56
DAD/Cop. L 0.05 0.36 52 35
Control-3 0 0 83 --
I p-DADMAC 0.10 0.50 35 56
p-Amphol.F 0.10 0.48 18 78
p-Amphol.G 0.10 0.44 13 84
p-Amphol.H 0.10 0.44 27 66
p-Amphol.J 0.10 0.46 18 78
p-Amphol.K 0.10 0.44 20 75
DAD/Cop. L 0.10 0.72 50 38
19
i
TABLE IV ( cont . )
Pitch Deposition
PolyDADMAC Versus Polyampholytes A ° K and
DADMAC copolymer L
I
Treatment Dosage ylbJton~ Pitch Deposit Percent Decrease in i
Actives Product Weiaht (ma) Pitch Deposit Weight
s's Basis
Control-4 0 0 84 --
Control-5 0 0 74 --
Average control (untreated) pitch deposit weight = 80 mg i
1 standard deviation = 7 mg
* Percent decrease in
pitch deposit weight = weight (control) - weight (treated) x 100
weight (control)
20 I
~0~~~~'f
In all the tests above using the procedures set forth in
Example I, the pitch dispersion used is a synthetic laboratory
I
pitch comprising a mixture of fatty and resin acids and esters,
sterols, sterol esters and fatty alcholos, which is representative
i
of actual softwood and/or hardwood pitch. This synthetic pitch is
used to form the 1% dispersion described in Example T, arid ranges
in content as described in Table V.
21
i
CA 02040337 2002-03-19
66530-492
TABLE V
Synthetic Laboratory Pitch
% Chemical Composition
5-50 Abietic acid (resin acid)
10-25 Oleic acid
5-10 Palmitic acid
10-35 Corn oil
5-15 Methyl stearate
2.5-7.5 Beta-sitosterol
2.5-7.5 Cholesteryl caproate
2.5-7.5 Oleyl alcohol
This synthetic laboratory pitch is dispersed in isopropanol
to form a 1% dispersion used as in Example I.
22
Image
