Note: Descriptions are shown in the official language in which they were submitted.
~49~L~s ~:
':
This invention relates to thermoplastic polymers con-
taining a surface alterir~ agent. By surface altering is meant
changing the surface characteristics of the thermoplastic ~oly
mer.
To achieve surface altering in thermoplastic ~olymers, -
it has heretofore been the general practice to incorporate
inorganic flatting agents such as calcium silicates, magnesium
silicates~ amorphous silica gels, and the likeO The use of
.
such inorganic particulate material has a dlsadvantage of causing
detrimental effects on the physical properties of the thermo-
.. . .
plastic material9 such as loss of impact strength~ toughness~
clarity~ processability, and the like. Inorganic flatting -
agents also suffer from poor dispersion in many cases~
.
~ An~ther prior method af achieving surface altering
~, . . .
;~ Or thermoplastics has been by calendering, but such mechanical
systems have the disadvantage of lack of uniform quality and
limited utility in that they cannot be used in an extrusion
process. Further disadvantages of mechanical flatting or sur-
face altering are that the calendering rolls ~ust be refinished
from time t~ time which is of some e~pense and incomrenience
Also~ calendering is not a flexible method in that one cannot
easlly vary the gloss reduction achieved; the only way to vary
-2-
~ :. ,' ' '
10~91~5 ~l ~
it is by changing the calendering rolls.
A different method of altering the surface of sub-
strates is~ of course~ by applying a coating composition which
is generally a synthetic resinous latex or dispersion of film
forming po]~.er or a solution of binder in solvent. It has been
suggested to achieve flatted coatings by incorporation o~ non-
crosslir~ed~ incompatible polymer particles in the coating
composition, but such coating systems are not useful for l~
altering the surface of thermoplastic polymers which are to l;
be subjected to an after-~reatment such as molding, heat forming,
or extrusion. - I;
It is an object of the present invention to provide
a simple method for uniformly altering the surface of thermo-
plastic polymers. It is a further object to provide thermo-
plastic polymers whose surface has been altered without affecting
other physical properties. A still further object is to provide
for uniform~ flexible, and economic flatting of thermopl&stic
polymers. A further object is to provide thermoplastic polymers
of reduced surface gloss. An additional object is to provide
flatting agents which can withstand the high temperatures used
- in extrusion and molding of thermoplastics~
These and other objects as will become apparent are
achieved by the present invention which comprises in one aspect
blends of extrudable~ moldable~ or heat formable thermoplastic
polymers and a surface altering agent comprising cross-li~ed ¦
- polymer particles having an average size of 1 to 30 microns.
; In another aspect the invention comprises a method of altering
the surface o~ thermoplastic polymers comprising blending ~ith
the thermoplastic polymer a controlled amount of surface alter-
ing agent comprising the above men~ioned cross-linked polymer
-3-
particles.
The present invention, therefore, in one aspect,
resides in a blend of an extrudable, moldable or heat formable
thermoplastic polymer and a surface altering agent for said
thermoplastic polymer, said surface altering agent comprising
cross-linked particles of polymers comprising about 86-99.95%
by weight of at least one monoethylenically unsaturated
monomer, about 0.05-4% by weight of at least one polyunsatura-
ted cross-linking monomer, and from 0% to about 10% by weight
of a latently cross-linkable addition polymerizable unsaturated
monomer having one or more reactive polar groups selected from
-OH, ` NH, -~-N ~ , -N=C=O, ` CHCN, -COOH, and -C~-~C-, said
particles having an average size of 1 to 30 microns, said '
surface altering agent being present in an amount of from
about 0.1 to 50 parts by weight per 100 parts by weight of
said blend.
In another aspect, this invention resides in a ¦
method for altering the surface of extrudable, moldable or
heat formable thermoplastic polymers comprising blending
therewith before or during processing cross-linked particles
of polymers comprising about 86-99.95% by weight of at least
one monoethylenically unsaturated monomer, about 0.05-4% by
I weight of at least one polyunsaturated cross-linking monomer,
and from 0% to about 10% by weight of a latently cross-linkable
addition polymerizable unsaturated monomer having one or more
reactive polar groups selected from -OH, ` NH, -C-N ~, -N=C=O,
~ CHCN, -COOH, and -~-,C-, said particles having an average
size of l to 30 microns, in an amou~t of from about 0.1 to 50
parts by weight per 100 parts by weight of the total blend.
In a further, more particular aspect, the invention -
-4- ~
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~9~
resides in a method as described in the immediately preceding
paragraph in which the surface altering agent is prepared by
polymerizing a monomer system comprising about 86-99.95% by
weight of at least one monoethylenically unsaturated monomer,
about 0.05-4% by weight o~ at least one polyunsaturated cross-
linking monomer, and from 0% to about 10% by weight of a
latently cross-linkable addition polymerizable unsaturated
monomer having one or more reactive polar groups selected from
-OH, ~ NH, -C-N~, -N=C=O, ~ CHCN, -COOH, and -C~-C-, in the
presence of a preformed acrylic-type polymer which is soluble
in said monomer system, thereby to form cross-linked polymeric
particles derived from said monomer system, said particles
being of average size of about 1 to 30 microns, dispersed in a
continuous phase of said preformed polymer, said preformed
polymer being compatible with said thermoplastic polymers.
The amount of surface altering agent included in the
blend is usually about 0.1 to 50 weight parts per 100 weight
parts of blend, preferably about 1 to 10 weight parts per 100
weight parts of blend. The exact amounts depend upon the par-
ticular surface properties desired and other factors such asthe particular thermoplastic polymer being altered and the
particular surface altering agent being employed.
Suitable thermoplastic polymers whose surfaces can
be altered by this invention include the vinyl chloride poly-
mers by which is meant polymers prepared from monomer systems
containing at least 50% vinyl chloride, more likely over 70
or 80~ vinyl chloride, and the remainder other monomers such
as propylene, vinyl acetate, ethylene and the like; acrylo-
nitrile-butadiene-styrene (ABS) copolymers, methyl methacrylate-
butadiene-styrene (MBS), nylons, polyethylene terephthalate,
~ -4a-
.
,
~6)9L91~S
polyethylene, polypropylene, polycarbonate, poiyalkyl
methacrylate, polyurethane, polystyrene, other thermoplastic
polymers, and blends of two or more thermoplastic polymers.
The term thermoplastic polymers is defined to exclude coating
systems, i.e., binder/solvent systems, and the thermoplastic
polymers to be surface altered are unsuitable for use in the
coating art.
The surface altering agent can be prepared by any
suitable process which results in cross-linked polymer
particles having an average size of 1 to 30 microns. The pre-
ferred process is by an endopolymerization technique wherein
the monomers that will ultimately form the particulate polymer
surface altering agent are polymerized in the presence of a
soluble preformed polymer which is dissolved in the above-
mentioned monomers, and is selected so that phase separation
takes place early in the -
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polymerization process. ~hen phase separation occurs, the
soluble preformed polymer becomes the continuous phase and the
polymerized monomers form the particulate polymer surface
altering agent as the discontinuous phase, i.e., as distinct
spherical particles dispersed in the soluble preformed polymer
phase. The particulate surface altering agent polymer is
insoluble in the so-called "soluble" polymer and the latter
becomes a carrier polymer in this technique, i.e., the original
preformed polymer which ~as dissolved in the monomer system
remains intact and, upon polymerization of the monomer system
going into the particulate polymer surface altering agent,
becomes the continuous phase having dispersed therein the par- ~ .
ticulate polymers of the average particle size of 1 to 30
microns.
Suitable compatible preformed carrier polymers
(soluble polymers) include polymethyl methacrylate or copolymers
of methyl methacrylate with less than 20% lower alkyl acrylate
units as the preferred polymers. Optionally, other co-monomers
can be used in small amounts, for example, styrene, vinyl
acetate, vinyl chloride, or acrylonitrile. A suitable molecular
weight for the compatible preformed carrier polymer is about
10,000 to about 300,000.
The suitable monomers for the surface altering agent
include about 86-99.95%, preferably about 98-99.5%, of at least
one monoethylenically unsaturated monomer, about 0.05 to 4%
preferably about 0.5 to 2.0% of at least one polyunsaturated
cross-linking monomer, and, optionally, up to about 10% of a
polar monomer, all on a weight basis. Suitable monoethylenically
unsaturated monomers are alkyl acrylates preferably having 4 to
8 carbon atoms in the alkyl, vinyl esters such as vinyl acetate,
vinyl propionate, vinyl stearate and the styrenes including
.
, . ~, .. .
" ~... .
. 104918S
styrene and ring-substitu-ted styrene. ~he preferred systems
contain a major part of styrenes and a minor part of(C~-C8) alkyl
acrylate, more preferably wherein the ratio of styrenes to
CL~~C8 acrylate is at least 1.5.
While it is broadly possible to include about 0.05
-to 4% of the polyunsaturated cross-linking monomer, it is much
pre~erred to use about 0.5 to 2% based on the total weight of
the monomer system. While the exact amount of cross-linking
monomer varies with different monomer combinations, I have
found the sl~ face alterin~ properties of a particular system
to vary greatly with small changes in amount of cross-li~king
monomer, and therefore it is important to determine with care .`.
the exact amount of cross-linker to be used. Exemplary cross- :
linking monomers.are those formed by the reaction of acrylic or ; :
methacrylic acid with ethylene~ propylene~ butylene, or hexa-
methylene glycols. In-addition~ divinyl benzene; divinyl or
diallyl compounds~ such as the divinyl ethers of the above ;~
glycols; diallyl phthalate; triallyl cyanurate; and other similar .
monomers h~ving more than one polymerizable group, may be used. ~ :
Additional polyethylenically unsaturated compounds include the :~
following: divinylpyridine, divinyltoluenes~ divinylnaphthalenes~
1,3-divinylxylene~ divinylethylbenzene, divinylsulfone7 poly-
vinyl or polyallyl ethers of glycol, or glycerol~ of pentaery-
` thritol~ of mono- or dithio- derivatives of glycols,.and of ;.
resorcinol~ divinylketone, divinylsulfide~ allyl acrylate~ :~
diallyl maleate~ diallyl fumarate, diallyl succinate, diallyl
carbonate~ diallyl malonate, diallyl oxalate~ diallyl adipate, ~ .
. diallyl sebacate, divinylsebacate~ diallyl tartrate, di.allyl
`. silicate, triallyl tricarballylate~ allyl methacrylate, triallyl
citrate, triallyl phosphate, N,N'-methlenediacrylamide, N,N'- .
ethylenediacrylamide, 1,2-di(a-methylmethylene sulfonamido)-
6 .~.. .
7~
;
.
. ~ ' ' ' ', ' ~ ' .
!,i ~, ! , .
-
~049~85
ethylene~ trivinylbenzene~ trivinylnaphthalene~ and polyvinyl-
anthracenes Substantially any monomers having more than one
addition-polymerizable olefinic group are useful. The preferred
I cross-linXing agents have the formula:
CH2 ~ ~ - ~ - OR
wherein Rl is H or CH3- and R is an ethylenically ~msaturated
radical. Where such compounds are substituted, the chain
length of such substitutions is not critical, but usually varies
from about 1 to 20~ preferably about 1 to 4 carbon atoms~
Optionally, the polymer particles can be made infusible
by secondary or latent cross-linking by including up to about
10 weight percent polar mo~omer, Generally, secondary or latent
cross-linking would occur during such steps as hot roll milling,
Banbury mixing or extrusion of the polymer mass The polar
monomers whicll are suitable for this function include those
that are residues of acrylics, and can be best exemplified by
the following: acrylic acid; methacrylic acid; acrylamide;
methacrylamides; epoxyalkyl acrylates or methacrylates, eOg.,
glycidyl methacrylate; monoacrylic acid esters of glycols;
hydroxyalkyl acrylates or methacrylates, isocyanatoalkyl acry-
lates and aminoalkyl acrylates or methacrylates, as well as
other compoundsdescribed below.
:~ ~
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104~ 35
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Examples of the secon~ry or li~tent cross-linkinr7
reactions ~hich are possible using haat and/or catalysis~are:
:. > NH + HO~ ~ >N~-
-CH-CH2 + HOOC- ~ -CH-CH2-O-CO-
5-CH-C/H2 + H-N- > -ICE-c~2 N
~ H :
-CH-CH2 + -CNHCH20R - ~ -CH-CH2-N~
: O OH CH20R
_ ~-CH2 + -C-~CH20H ~ fH-CH2-
OH
_CH-CH2 ~ -C~-/CH2 >
- CH2 H~
2 (-cl~HcH2oH) > -9NH5H2oCH2NHC-
~ ~0 ~[
10~N~C=O + HOC~ NH-~-OC-
-~=C=O + H~ _ 1O H~
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~C~491~35
Addition polymcrizable unsaturated monomers containing such
groups are well known in the art, examples being isocyanates
such as isocyanatoethyl methacrylate, epoxy compounds such as
glycidyl methacrylate~ aminoalkyl compounds such as methyl-
aminoethyl methacrylate~ and t-butylaminoethyl methacrylate,
amides such as methacrylamide, guanamines such as 4-penteno-
guanamine, hydroxyalkyl esters such as hydroxyproFyl meth-
acrylate and hydroxyethyl methacrylate~ nitriles such as
methacrylonitrile, N-alkoxyalkylamides such as methoxymethyl
methacrylamide, hydroxyal'~yl amides such as N-methylol meth-
acrylamide, the analogs of the above methacrylic acid derivatives
with other unsaturated acids such as acrylic acid and itaconic
acid~ such acids themselves; dic~rboxylic acids such as maleic
acid and half esters and half amides thereof~ vinyl ethers of
glycols such as ethylene glycol, and so forth.
. As may be seen, the latently cross~ able add.ition
polymerizable unsaturated monomers have reactive polar groups
selected from those including -OH,> NH, -~-N<, -N=C=O,~ CHCN,
_COOH~ and -C -~ - .
While it is not usually necessary to provide for such
secondary cross-linking, in systems where it is necessary or is
preferred, the secondary cross-linking monomers are present in
amounts of from 0.05 to 10%, preferably from 0 1 to 3~ by weight,
based on the total monomers that form the particulate polymer~
When such monomers are utilized~ and contain alkyl groups, the
groups usually contain from about 1 to 20~ preferably about 1
to ~ carbon atoms~ The preferred secondary cross-linking co-
monomer is methacrylic acid and is usually utilized in amounts
: of less than 2~ by weightO
_9_
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1049~1L8~ ~
An alternative method to this endopolymerization
teclmique for preparation of the surface altering agent com-
prises introducing the monomers in water containing a suspending !
agent under conditions to form suspended monomer globules
having an average size of about 1 to 30 microns, and then
polymerizing and isolating by conventional methods.
Whether the particles are prepared by the endopoly-
merization technique or the modified suspension technique~ the
polymerization is conveniently effected by conventional free
radical pol~rmerization catalysts, such as redox catalysts and ~-
peroxy compo~lds~ heat or irradiation. In general, these
catalysts are present in amounts of from about 0.02 to 1.0, il
preferably from about 0.2 to 0.5 weight percent, based on the 1 -
total monomers that form the surface altering agent particulate
polymer. The catalyst may be a combination of both high and
low temperature components if it is desired that the above-
noted secondary or post polymerization cross-linking be enhanced.
Exemplary catalysts include benzoyl peroxide, acetyl peroxide~
i t-butyl peracetate~ dicumyl peroxide~ azoisobutyronitrile (AIBN),
t-butyl hydroperoxid~, and t-butyl peroxy pivalate. Moreover, ¦-~
.
either heat or irradiation, or a single compound catalyst in com-
bination with heat and/or irradiation may be utilized. Further,
it should be noted that metal accelerators are o~ten useful when
irradiation catalysis is used~ for example wqth the use of ultra-
violet light. Heat or radiation functions can be used in combin-
ation with other free-radical generating materials.
If the surface altering agent polymer particles are
below an a~er~ge size of 1 micron they do not have the desired
effect on the surface Or the thermoplastic polymers, i.e., gloss
reduction cr anti-blocking. When the avera~e particle size is
--10--
,, ' '~ ~ '
~4~ S ~ ~
above 30 microns, the surface texture of the extruded or molded
thermop'l~stic pol~mer article becomes objectionably rough and
unattractive for most applications, although such articles could
be useful, possibly, for certain speciality applications. The
5 particle size distribution can be either narrow or broad, and by'
proper choice of particle size range and distribution, vary-
ing surface effects can be obtained. For example, for print-
ability a narrow distribution is preferred, whereas for gloss
reduction, a broader distribution is preferred.
If the surface altering agent is prepared by the endo-
polymerization technique~ it is a solid material at room
temperature, in the form of a solid composite of the surface
altering particles in a matrix of the continuous phase carrier
polymer. The solid composite is preferably granulated and
thereafter blended with the thermoplastic polymer in the de
sired amounts before or during processing of the thermoplastic.
By proper selection of monomers going into the surface
altering agent polymeric particles it is possible to achieve a
desired refractive indexO For applications wherein clarity of
the thermoplastic polymer is necessary, it is preferrea to
select the monomers so that the cross-linked particles have a
' refractive index within about 0.'005 units of the refractive
' index of the thermoplastic/carrier polymer blendO In systems
wherein clarity is not necessary or desired, the refractive
index of the surface altering agent polymer particle is not
important.
~ The surface altering properties achievable by the
; present in~ention include flatting, anti~blocking~ improved
printability, scuff resistance, or hiding of surface imper-
fections of thermoplastics. By varying the amounts of surface
-11-
- . , . , . ... , . , . , , , lr
.
, " ' ' ., , '.
, i! I l i;
,. . .
~918~
albering agents, one can achieve anti-blocking without necess-
arily flatting the thermoplastic materialO
The blends of the invention are useful as single layer
sheets or as laminate or other molded~ cast~ extruded~ or heat
formed articlesO The blends can further include dyes, pigments,
colorants, stabilizers~ plasticizers~ fillers, and other con-
ventional additives The blend can be thermo~ormed without
affecting the surface alteration.
When the surface altering agent is prepared ~y the
endopolymerization process~ the soluble carrier polymer, i.e.,
the preformed polymer, should be compatible with the thermo-
plastic polymer which is to be altered. For example~ uhen it
is desired to prepare flatted PV~ sheet~ one preferred surface
altering agent/carrier combination is styrene/butyl acrylate/
ethyl acrylate/allyl methacrylate (61/3~/305/1.5) as surface
altering agent in methyl methacrylate/ethyl acrylate (91/9)
Garrier polymer.
The following Examples are presented to illustrate
~ several embodiments of the invention bu~ it should be under-
stood that the invention is not in any way limited to the
embodiments illustrated.
'' ' .: '
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.1
91~35
EXA~lPLE 1
This example shows preparation of a surface altering i
agent in a preformed polymer. 26.7Y pounds of a preformedj
polymer o~ ethyl acrylate/methyl methacrylate copolymer (9/9'
by weight) is dissolved in a monomer system comprisin~ 4~.17
pounds of styrene monom~r, 2L~o62 pounds of _-butyl acrylate,
and 2.90 pounds of ethyl acrylate at 50oC. After two hours of
stirring~ the preformed polymar is completely dissolved in the
monomer system. After the solution has been cooled to 30~C.,
the follo~.ring ingredients are then added with appropriate
stirring to insure that each is completely mixed before the
next is added: 1.085 pounds of allyl methacrylate as cross-
linking agent for the surface altering agent, 0.0009 pounds of
oxalic acid, 0.0725 pounds Of tertiary-dodecylm3rcaptan, 0.1449
pounds of t-butyl peroxypivalate, 0.0725 pounds of 25% acetyl
peroxide solution in dimethyl phthalate, and 0.1449 pounds of
dicumyl peroxide. This mixture is then polymerized in an air
circulating oven for 16 hours at 660C., 2 hours at 800C., a~d
then 6 hours at 120C. The resulting 1/2" slab of polymer is
broken and further granulated intv particles capable of passing
through a 5/16" mesh screen. The endopolymeric surface altering
agent is characterized by a particle size range of about 1 to
35 microns in diameter, as determined by elsctron microscopy,
the average particle size being about 1.5 microns. The
acetone extractables, as an indication of degree of cross-
linking, is 41% by weight~ and the s-.~elling ratio as an
indication of crossiink density is 7Ø ;
~ ' ' ' ' " ' .
~ - 13 -
~(~49113S
EXAMPLE 2
.
This example illustrates a blend of a surface altering
agent with a thermoplastic polymer. T~o parts by weight of the
I surface altering agent/carrier polymer composition in granular
form prepared in Example 1 and 100 parts by weight of polyvinyl
chloride having a K value of 69 and containing therein 50 parts
of di(2-ethylhe~l) phthalate (DOP) as plasticizer, 2 parts by
weight of dibutyltin mercaptoacetate stabilizer and 0.25 parts -
by weight of stearic acid lubricant are mixed together and
kneaded on a roll mill for 5 minutes at 3250C. at a speed
differential of 20/20 RPM to form a 15 mil thick film. The
surface of the film in contact with the rolls is painted black
to eliminate reflection from the~second surface and the specu-
lar gloss measured at 600 angle of incidence~ For comparison,
a 15 mil thick film containing 2 parts by weight of an inorganic
su~face altering a~ent (amorphous silica) prepare~ b~J the same
working conditions and a 15 mil thick film containing no surface
. ; altering agents, polymeric or inorganic in nature, are pre-
; pared and measured~ The results are shown in Table 1.
TABLE 1
. Clarity
. % White %
Additive600 Gloss (%) Li~ht TransO Haze
: Thls invention1303 86.3 13.7
Amorphous Silica Gel 38.5 83~5 98
Unmodified Control 65.7 83.0 16,2 .
:
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1(~49~85
EX~MPIE ~
This example shows a blend of surface alterin~ agent
and rigid (unplasticized) PVC. 5 parts by weight of surface
I altering agent composition from Example 1 in granular form and
100 parts by ~eight of polyvinyl chloride having a K value of
61 and containing therein 12 parts by weight of an MBS type
impact modifier (~cryloid ~ KM 611), 3 parts by weight of
an acrylic processing aid (Acryloid ~ K120N), 2 parts by
weight of dibutyltin mercaptoace-tate, 0.75 parts by weight of
glycerol monostearate an~ 0.75 parts by weight of partially
saponified ester are mixed together and kneaded by a roll for
minutes at 3500F. at a speed differential of 20/20 RPM. A
35 mil sample is removed from the roll mill, back painted black
to eliminate reflection from the second surface and the specular.;
gloss measured at 600 angle of incidence. The balance o. the
stock is milled Ior an additional 3 minutes at 3500Fo af-ter ~ .
: which the kneaded mixture is molded into a 0.100" sheet at 3500F.
70 tons pressure ~ith a cycle of.3 min. preheat/2 minutes press/
.:
~ 3 minutes cooling~ The molded sheet is tested for V-notch Izod
: 20 impact strength, and further subjected to measurement for light
transparency in comparison with molded sheet containing 5 parts
of an inorganic surface-altering agent (amorphous silica gels) .
prepared by the same working conditions and a molded sheet con-
taining no surface altering agent~ polymeric or inorganic in
~5 natureO The results are shown in Table 2 :
TABLE 2
Izod Impact Clarit
600 Gloss Strength Y
Additivo . ~ ft -lb.~in. 7~WL ~aze .:
This invention 5 5. 515. 6 78 .1 9 . 2
. Amorphous Silica 5 7.80.72 37.1 100.0
: Gel
Unmodified Control 0 13~9 22.5 73.0 11.1 :
-15-
.
:, ' ' ' , :
As is apparent from the above table, the surface alter-
ing agent composition of this invention provides superiGr
gloss reduction, impact s-trength and clarity over the
amorphous silica gels.
EXAM LE 4
The procedure and compositions disclosed in Example
1 are followed except that the amounts of styrene monomer
and n-butyl acrylate monomer are 61.50 pounds and 7.29
pounds, respectively, and tes-ted for gloss reduction
according to the procedure used in Example 1, Table 1.
The results are a 60 g~oss (%) of 18.5.
EXAMPLE 5
The procedure and compositions disclosed in Example
1 are followed except that the amount of s-tyrene monomer
is 41.17 pounds and 27.62 pounds of 2-ethylhexylacrylate
are substituted for the butyl acrylate, and tested for
gloss reduc-tion according to the procedure used in
Example 1, Table 1. The resul-ts are a 60 gloss (%) of
11Ø ''"'
EXAMPLE 6
This example illustrates a suspension polymerization
process for preparing the surface altering agent of the
invention in a carrier polymer (endopolymer). The mixing
procedure disclosed in Example 1 is followed using as ;
the preformed polymer 266.2 grams of a copolymer o-f about
I0% ethyl acrylate copolymerized with about 90% of methyl
methacrylate. The monomer system in which the preformed '
polymer is dissolved cnnsists o-f 430.2 grams of styrene
monomer, 240.6 grams of n-butyl acrylate, and 27.62 grams
of ethyl acrylate. The following ingredients are added
to the syrup: 21.70 grams of allyl methacrylate, 7.202
~ - 16 -
,' .
: .. .. .
~L91~5
grams of t-butyl peroxypivalate, and 7.202 grams of
lauryl peroxide. In a suitable reaction vessel a
mixture of 986.4 grams of deioni~ed water, u.86~ grams of
Amberlite W-l suspending agent (Rohm and Haas Company)
1.380 grams of sodium nitrate,
16a -
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: :'
and 1.380 grams of potassium chloride is prepared. The
monomer/polymer solution is then pumped into the vessel
containing the aqueous solution. The mix-ture is sub-
jected to intermittent agitation to form a stable suspen-
sion. The suspension is stirred at 300 rpm and polymeri-
zed at 70 C. for l hour, 80C for l hour and 90C. for
1 hour. The product suspension is cooled and isolated,
and the resulting endopolymer/carrier beads are mostly
between 0.085 and 0.0425 inches in diameter. The endo-
' ' 'polymer is characterized by particle polymer spheres
ranglng from l to 33 microns in diameter with an average
size of 6. The surface altering agent prepared is tested
for gloss reduction according to the procedure used in
Example 1, Table 1. The results are a 60 gloss (%) of
12Ø
-
EXAMPLE 7
This example illustrates a suspension process for
preparing the surface altering agent particles without
employing a carrier polymer. In a suitable reaction
vessel a mixture of 760 grams of deionized water, 30.0
grams of an 8% aqueous solution of hydroxyethyl cellu-
lose, 4.00 grams of Acrysol~ GS s~spending agent (sodium
polyacrylate from Rohm and Haas Company), 0.300 grams
of "Pharmagel"* (gelatin), and 4.00 grams of sodium
chloride is stirred unitl all components have dissolved.
Separately a mixture of 266 grams of n-bu-tyl acrylate,
478 grams of styrene, 32.0 grams of eth~l acrylate f 24.0
grams of allyl methacrylate, 8.00 grams of benzoyl perox-
ide, and 8.00 grams of lauryl peroxide is prepared. This
monomer mixture is added to the aqueous solution, and the
agitator blade is positioned at the interface between -the
aqueous and organic phases. The mixt~re is submitted to
- 17 -
,
,~ ~ ., , . , . . .. : ., , :
9~5
to intermittent agitation to form a stable suspension.
The suspension is stirred at 300 rpm and heated to
75C. over a 40 minu-te period. The polymerization is
completed
- 17a-
* Trademark for spe~ially purified gelatin.
':' ': ' , . :
....
lO~g~
using the following time/temperature cycle~ hours at
750C., 1 hour at 830C.~. 1 hour at 91C., and 1 hour at.97~C.
The product suspension is cooled and isolated by methods known
in the art. The resulting polymer particle range from 1 to 30 :.
5 microns in diameter~ with an average size of 12 microns. The
surface altering agent prepared is tested for gloss reduction 1
according to the procedure used in Example 1. The results are
a 600 gloss (%) of 17.0 j:
EXAMPLE 8 l~
~he mixing procedure disclosed in Example 1 is followed 1- .
dissolving 888 grams of the same carrier polymer in a monomer
system consisting Or 1~6~ grams of styrene monomer, 816 grams
of n-butyl acrylate, and 96 grams of ethyl acrylate, then the
following ingredients are added to the cooled syrup: 11.9 grams ~ .
of 1,3-butylene glycol dimethacrylate, 2.~ grams Or tertiar~
dodecylmercaptan~ 0.86 grams of 2.8% aqueous oxalic acid, ~.8 :¦
grams of t-butyl peroxypivalate~ 2.~ grams of 25% acetyl per- i:. :
` oxide solution in dimethyl phthalate~ and ~.8 grams of dicumyl ' .
peroxide. The resultant mixture is placed in a bag container I .
and bulk polymerized in an air circulating oven for 16 hours :.:
at 66~C.~ 2 hours at 800C. a and then 6 hours at 120C. After ~-. ..
the b.ag is removed from the resulting opaque 1/2" slab of polym2r
the slab is broken and further granulated into particles capable . ~ .
Or passing through a 5/16" mesh screen~ and tested for gloss : -
-:' 25 reduction according to the procedure used in Example 1. The
results are a 60 gloss (~) of 16Ø .. ~
~ EXAMPLE 9 .
The procedure and compositions disclosed in Example 6 .
.: are followed except that 5.9 grams Or 1~3-butylene glycol di-
acrylate is used in place of the 1~3-butylene glycol dimeth- '
acrylate, and test~d for gloss reduction according to the :
-18-
,,.~
.. .
10~9~1L85
procedure used in Example 1, Table 1. The results are a
gloss (%) of 16Ø
EXAMPLE 10
The procedure and compositions disclosed in Example
6 are followed except that 11.9 grams of trimethylpropane
trimethacrylate is used in place o-f the 1,3-butylene gly- :
col dimethacrylate and tested for gloss reduction accord
ing to the procedure used in Example 1, Table 1. The
results are a 60 gloss ~) of 14Ø
EXAMPLE 11
The procedur~ and compositions disclosed in Example
6 are followed except that 2.~ grams of divinylbenzene is
used in place of the 1,3-butylene glycol dimethacrylate,
and tested for gloss reduction according to the procedure
used in Example 1, Table 1. The results are a 60 gloss
(%) of 20Ø
EXAMP~E 12 (Comparative)
~ his example shows the importance of selecting -the
proper amount of cross~linking monomer, and its relation
to properties obtained.
A. The procedure of Example 1 is followed only
varying the amount of cross-linking agent, allyl methacry-
late, and the following Table gives resul-ts of acetone
extractables test swelling ratio, -60 gloss, and disper-
sion
.
., :
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:' ' ' ' ' ' . '' ',' . ". ', . ' :'. " ' ' ' '~ ' ' ' ' ' '
.. ,, ., , , , . . : ~
~; ! ' ! '
1,
~0491
% Extractables -.
% Cross-linker ~27% of Soluble, .
In Monomer Preformed Carrier Swelling 60~
Mixture Polymer) Ratio~loss Dis~er_ion
100 _~3 Excellent
-5 . 78.5 44 56 ,
0.75 58.9 16.~ 71 , .
1 51.2 10.3 16 ` "
1.5 39.2 6.~ 12 Grainy ¦~
2 29.9 4.7 16 Undispersed
3 30.6 ~.6 ~2 .
B. Surface altaring agent was prepared by the carrier l- -
,.: .
- polymer technique of Example 1 but with styrene and divinyl
benzene as the sole monomers, and was incorporated in the same
. . .
15 manner in PVC. By varying the ratio of styrene to cross- .~ -
linking monomer, varying results were ob~ained. At from 0 to -:
. .
. O.1% crosslinker in the mono~er mixture, the surface altering
agent was well dispersed in the PVC, and the 600 gloss was ~ :
reduced from 91 for the PVC without surface altering agent, to .
. 20 84~ 76 and 58 respectively ~or 0, 0.05 and 0.1% cross-linker. :.
At 0.5 to 1~ cross-li~ker the dispersibility was poor to very
. poor and at 3 and 5% cross-linker~ the surface altering agent .. .
could not be dispersed at all and the test sheets had large
visible particles which indicated gross heterogeneity and lack
of'SurIace sltering'as defined in this specificaticn.
. '. ~: ' '. .
- 20 -
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