5
7/17/2019 Us 4255545 http://slidepdf.com/reader/full/us-4255545 1/5 Umted States Patent {19] [1 1} 4,255,545 Hurlock et al. [45] Mar. 10, 1981 [54] DISCRETE BEAD POLYMER PROCESS [56] References Cited U.S. PAT DOCUMENTS [75] Inventors: John R. Hurlock, Hickory Hills; ENT Louis A_ Gonna’ Napervme, b o t h of 4,011,388 3/ 1977 Murphy et a1. .................... 526/201 1“- Primary Examiner-J. Ziegler _ Attorney, Agent, or Firm-—Kinzer, Plyer, Dorn & {73] Ass1gnee: Nalco Chemical Company, Oak Mcgachmn Brook, Ill. . {57] ABSTRACT [2 1] Appl. No.: 109,985 Discrete particles of sodium polyacrylate of high mo lecular weight and in which the majority of the particle [22] Filed: Jan. 7, 1980 size is in the range of not less’than 0.5 mm. nor more than 1.0 mm. diameter are achieved, in an economy of [51} Int. Cl.3 .............................................. C08F 2/00 production, by Suspension polymerization in stages of [52] .......................... 526/201; 525/274; 40° C‘ (2 hours), 50° C- (2 hours) and 60” C. (2 hours) in 525/288 the presence of a protective colloid. [58] Field of Search .............. .. 526/20l; 525/288, 274; 260/336 UA, 33.8 UA 2 Claims, 2 Drawing Figures

Us 4255545

Embed Size (px)

DESCRIPTION

oi

Citation preview

Page 1: Us 4255545

7/17/2019 Us 4255545

http://slidepdf.com/reader/full/us-4255545 1/5

Umted

States

P at en t { 1 9 ] [ 1 1 } 4 , 2 5 5 , 5 4 5

H u r l o c k e t

a l .

[ 4 5 ] Mar. 1 0 ,

1 9 8 1

[ 5 4 ] DISCRETE BEAD POLYMER PROCESS [ 5 6 ]

R e f e r e n c e s

C i t e d

U . S .

PAT DOCUMENTS

[ 7 5 ]

I n v e n t o r s :

J o h n

R . H u r l oc k ,

H i c k o r y

H i l l s ;

ENT

Louis A_ Gonn a’ Napervme,

both of 4 , 0 1 1 , 3 8 8

3 /

1 9 7 7 Murphy e t a 1 . . . . . . . . . . . . . . . . . . . . . 5 2 6 / 2 0 1

1 “ - P r i m a r y E x a m i n e r - J .

Z i e g l e r

_ A t t o r n e y , A g e n t , o r

Firm-—Kinzer,

P l y e r , D o r n &

{ 7 3 ] A s s 1 g n e e :

N a l c o

C h e m i c a l C o m p a n y ,

Oak

Mcgachmn

B r o o k , I l l .

. { 5 7 ]

ABSTRACT

[ 2

1 ]

A p p l .

N o . :

1 0 9 , 9 8 5 D i s c r e t e p a r t i c l e s o f

s o d i u m

p o l y a c r y l a t e o f h i g h mo

l e c u l a r w e i g h t a n d

i n

w h i c h t h e m a j o r i t y o f t h e p a r t i c l e

[ 2 2 ]

F i l e d : J a n . 7 , 1 9 8 0

s i z e

i s

i n

t h e r a n g e

of n o t

l e s s ’ t h a n 0 . 5

mm. nor mor e

t h a n 1 . 0 mm. diameter a r e a c h i e v e d , i n

an ec on omy

of

[ 5 1 } I n t . C l . 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C 08 F 2 / 0 0

p r o d u c t i o n ,

by S u s p e n s i o n p o l y m e r i z a t i o n i n s t a g e s o f

[ 5 2 ]

. . . . . . . . . . . . . . . . . . . . . . . . . .

5 2 6 / 2 0 1 ;

5 2 5 / 2 7 4 ; 4 0 °

C ‘ ( 2

h o ur s ) , 5 0 °

C -

( 2 h o u r s ) and 6 0 ” C . ( 2

h o u r s ) i n

5 2 5 / 2 8 8

t h e p r e s e n c e o f

a

p r o t e c t i v e c o l l o i d .

[ 5 8 ] F i e l d o f Search

. . . . . . . . . . . . . .

. . 5 2 6 / 2 0 l ; 5 2 5 / 2 8 8 ,

2 7 4 ;

2 6 0 / 3 3 6 UA, 3 3 . 8 UA

2

C l a i m s ,

2

D r a w i n g F i g u r e s

Page 2: Us 4255545

7/17/2019 Us 4255545

http://slidepdf.com/reader/full/us-4255545 2/5

4 , 2 5 5 , 5 4 5

a r . 1 0 , 1 9 8 1

S .

P a t e n t

Page 3: Us 4255545

7/17/2019 Us 4255545

http://slidepdf.com/reader/full/us-4255545 3/5

4,255,545

1

DISCRETE BEAD

POLYMER

PROCESS

SUMMARY

OF THE INVENTION

T h i s i n v e n t i o n i s

c o n c e r n e d w i t h t h e

p r o d u c t i o n

o f

p o l y s o d i u m a c r y l a t e o f h i g h m o l e c u l a r w e i g h t , g r e a t e r

t h a n

t e n m i l l i o n

on

dry

bead

f o r m .

The

p o l y a c r y l a t e i s i t s e l f w a t e r

s o l u b l e

b u t b e c a u s e o f

t h e h i g h m o l e c u l a r w e i g h t ,

e v e n a

?ve p e r c e n t s o l u t i o n

would b e c o m p a r a b l e i n v i s c o s i t y t o a J e l l - O p u d d i n g ,

n o t e a s i l y t r a n s p o r t a b l e . T h e r e f o r e ,

i t i s

p r e f e r a b l e t o

h a v e t h e p o l y a c ry l a t e

i n l a t e x

f o r m w h i c h

may

b e t h i r t y

p e r c e n t

a c t i v e ,

a

p a r t i c le s i z e o f , s a y , one to t w o mi

c r o n s

i n s u s p e n s i o n .

N e v e r t h e l e s s ,

t h e

l a t e x i s n o t a l w a y s s t a b l e ,

e s p e c i a l l y

i n

e x t r e m e l y h o t o r e x t r e m e l y c o l d w e a t h e r i n a r e a s o f

t h e w o r l d where t h e p o l y m e r i s b e i n g u s e d f o r s e c o n d

a r y or t e r t i a r y

o i l

r e c o v e r y ,

a s

i n Saudi

Arabia

o r

A l a s k a . Another u s e

of

t h e

p o l y a c r y l a t e

i s a s

a

coagu

l a n t f o r

w a t e r

c l a r i ? c a t i o n .

B e c a u s e o f

i n s t a b i l i t y , t h e

p o l y m e r

s o l i d s

s e p a r a t e

o u t

a n d

s e t t l e i n

t h e

b o t t o m o f

t h e

d r u m o r

o t h e r s h i p p i n g

c o n t a i n e r .

The p r o b l e m s i n h e r e n t w i t h

t h e

w a t e r

s o l u t i o n

a n d

t h e l a t e x

a r e s o l v e d b y

p r o d u c i n g

p o l y s o d i u m a c r y l a t e

o f h i g h m o l e c u l a r w e i g h t i n e s s e n t i a l d r y b e a d

f o r m ,

n e a r l y o n e h u n d r e d p e r c e n t a c t i v e , c o n s t i t u t i n g

t h e

p r i m a r y o b j e c t o f t h e p r e s e n t i n v e n t i o n .

As

a g e n e r a l

r u l e ,

t h e

l a r g e r

t h e

polymer s p h e r e s o r b e a d s ,

up

t o a

c e r t a i n p o i n t , t h e

e a s i e r i t

i s

t o d r a i n

o r

f r e e

t h e

polymer

f r o m t h e s u s p e n d i n g h y d r o c a r b o n s o l v e n t o c c l u d e d

d u r i n g p o l y m e r i z a t i o n .

H o w e v e r ,

t h e

s m a l l e r t h e p o l y

me r

s p h e r e s ,

t h e e a s i e r i t

i s

t o f r e e t h e b e a d s

of

w a t e r

o c c l u d e d d u r i n g p o l y m e r i z a t i o n , a n d

t o

d i s s o l v e them

r a p i d l y i n w a t e r a t a n y

g i v e n

t e m p e r a t u r e .

F i s h e y e

f o r m a t i o n

i s

a l s o

e l i m i n a t e d

when

a p p l y i n g

t h i s

p o l y m e r

f o rm . T h e r e f o r e , p o l y m e r

b e a d s

m u s t b e n e i t h e r

t o o

s m a l l n o r t o o l a r g e i n o r d e r t o combine

t h e

b e s t o f

t h e

a b o v e c h a r a c t e r i s t i c s i n a s i n g l e p o l y m e r b e a d p r o d u c t .

5

1 5

2 0

2 5

3 5

The

d r i e r t h e p r o d uc t , t h e

e a s i e r

i t i s t o t r a n s p o r t

and

4 0

have

assurance

o f

s t a b i l i t y .

The cu s t ome r w i l l d i s s o l v e

t h e

b e a d s i n w a t e r , making

h i s

o w n

p r o d u c t

f o r u s e i n

t h e ? e l d , whether

n

o i l r e c o v e r y , w a t e r c l a r i ? c a t i o n ,

o r

w h a t e v e r .

A n o t h e r o b j e c t o f t h e i n v e n t i o n

i s

t o p r o d u c e

t h e

b e a d s a s d i s c r e t e , s y m m e t r i c a l p a r t i c l e s

i n

t h e optimum

d i a m e t e r

f o r e a s y d r a i n a g e

o f

t h e h y d r o c a r b o n p h a s e

a f t e r

p o ly m e r i z a t i o n , t o g e t h e r w i t h u l t i m a t e e a s e o f

w a t e r s o l u t i o n

b y t h e c u s t o m e r .

Th e

mo re d i s c r e t e and

t h e

more s y m m e t r i c a l

t h e

b e a d s

t h e

more

r e a d i l y

t h e y

d i s s o l v e .

S i n c e e f f i c i e n c y o f t h e polymer s e e m s t o b e

k e y e d t o t h e m o l e c u l a r w e i g h t , a n o t h e r o b j e c t

i s

t o

d e v e l o p p r od u c t i o n p a r a m e t e r s

f o r

a

h i g h

m o l e c u l a r

w e i g h t

p r o d u c t

w h i c h

a l s o

a c h i e v e s

t h e f o r e g o i n g o b

j e c t i v e s .

I n

a c c o r d a n c e

w i t h t h e p r e s e n t i n v e n t i o n ,

i n a c h i e v

i n g

t h e

o b j e c t s s e t f o r t h a b o v e , t h e

p o l y m e r

i s

p r o d u c e d

i n s u s p e n s i o n ( s u s p e n s i o n

p o l y m e r i z a t i o n ) ,

t h e l i q u i d

medium b e i n g a homogeneous m i s c i b l e

m i x t u r e

o f

a

h y d r o c a r b o n s o l v e n t , a

p r o t e c t i v e

c o l l o i d

a n d w a t e r .

The water a l l o w s t h e m o n o m e r (sodium a c r y l a t e ) t o

t r a v e l t o t h e p o l y m e r i z i n g s i t e s ; t h e o i l

o r

s o l v e n t d i s

s o l v e s t h e p r o t e c t i v e c o l l o i d a n d i s s e l e c t e d

t o

h a v e

a b o u t

t h e same d e n s i t y

o r s p e c i ? c

g r a v i t y

a s

t h e aque

o u s

monomer

o l u t i o n , i t

a l s o serves

a s

a h e a t - t r a n s f e r

m e d i u m , a n d i t

k e e p s t h e

s u s p e n s i o n

s t a b l e d u r i n g r e a c

t i o n ; t h e p r o t e c t i v e

c o l l o i d

h a s b o t h h y d r o p h i l i c

a n d

h y d r o p h o b i c c h a r a c t e r i s t i c s b y w h i c h

t h e p r o t e c t i v e

5 0

5 5

6 5

2

c o l l o i d i s o l a t e s a n d c o n t r a c t s t h e

w a t e r

d r o p l e t s a s t i n y

r e a c t o r s - w h e r e

p o l y m e r i z a t i o n t a k e s p l a c e .

BRIEF

DESCRIPTION

OF T H E ‘

DRAWINGS

F I G . 1 i s a

p h o t o g r a p h

(50X) s h o w i n g t h e f o r m

o f

u n d e s i r e d a g g r e g a t e s ; a n d

F I G . 2 i s a

p h o t o g r a p h ( 2 0 X )

s h o w i n g

d i s c r e t e

beads.

EXAMPLE

N o .

2 2 1 )

P r e p a r a t i o n o f

P o l y s o d i u m A c r y l a t e

B e a d s

i n

S u s p e n s i o n

E x a m p l e M 0 2 2 1 )

P r e p a r a t i o n o f P o l y s o d i u r n

A c g l a t e

B e a d s i n

S u s E n s i o n

R e a g e n t s W e i g h t s , G r a m s

A c r y l i c

A c i d

1 5 . 3 5

Water 2 0 . 4 0

S o d i u m

H y d r o x i d e

(pH

8 . 5 )

1 6 . 7 5

Catalyst

-

( 2 . 5 %

i n

H 2 0 1 . 0 ml

T o l u e n e

( S o l v e n t )

1 4 8

T e t r a c h l o r o e t h y l e n e

( S o l v e n t

24 5

P o l y m e t h y l

M e t h a c r y l a t e

(Protective Colloid:

4 . 2

ldrich

LV.

=

. 2 )

P r o c e d u r e :

The p r o t e c t i v e c o l lo i d w a s

d i s s o l v e d

i n t h e

s o l v e n t

s y s t e m c o n t a i n e d i n

a

s u i t a b l e r e a c t o r by

h e a t i n g

t o

6 0 °

C . , t h e n c o o l e d t o 4 0 ° C . and a g i t a t e d 400

RP M . The

c a t a l y s t was d i s s o l v e d i n

t h e

a q u e o u s

(pH 8 . 5 ) s o d i u m

a c r y l a t e

m o n o m e r

and t h i s w a s added t o t h e r e a c t o r

w h i l e a g i t a t i n g a t 4 0 0 RP M .

An

N; s p a r g e was a p p l i e d

( r a t e o f

1 5 0 0

cc

p e r m i n u t e )

and

a f t e r

?ve m i n u t e s a t 5 4 °

C . t h e

polymer

w a s

o b s e r v e d f o r m i n g

o n t h e t h e rmom

e t e r . P o l y m e r i z a t i o n w a s a l l o w e d t o c o n t i n u e f o r t h r e e

h o u r s a t

6 0 ° C .

( p l u s

o r m i n u s 2 ° ) .

The N; s p a r g e w a s d i s c o n t i n u e d , twenty

?ve

m l .

o f

B20 w a s i s t i l l e d

o f f

over

a

ninetyminute

p e r i o d

a t

9 2 ° ~ 1 1 2 ° C .

Th e

r e a c t i o n m i x t u r e w a s c o o l e d and

t h e n

f i l t e r e d

t o

r e c o v e r

t h e

p o l y m e r , p o l y s o d i u m a c r y l a t e

w h i c h h a d b e e n

t h u s

s e p a r a t e d b y a z e s t r o p i c d i s t i l l a

t i o n .

Th e

polymer w a s

s c r e e n e d through a

No. 1 8

and No.

3 5 s i e v e t o

s e p a r a t e

s m a l l e r d i s c r e t e b e a d s o f

p o l y m e r

f r o m a g g r e g a t e s :

A-l

3 1 grams o f l a r g e r

t h a n

2 . 5 mm e a d s and

a g g r e

g a t e s ;

B — l 5 - . 0

grams

1 . 0 - 2 . 5

mm e a d s ; i n t r i n s i c v i s c o s i t y

1 4 . 0 ,

RSV f

1 6 . 7

a n d s a l t v i s c o s i t y 1 4 0 c p s .

C — 6 . l grams of . 5

t o

1 . 0 mm

e a d s ;

i n t r i n s i c v i s c o s

i t y o f 9 . 6 8 , RSV f

1 0 . 7 a n d s a l t

v i s c o s i t y o f 1 2 5

c p s .

D — 0 . l grams of l e s s t h a n

or

e q u a l t o 0 . 5 mm eads

T h e ' a b o v e e x a m p l e i s

e x p e r i m e n t

N o . 2 2 1 t a b u l a t e d

i n t h e ‘

f o l l o w i n g t a b l e

a l o n g

w i t h many

o t h e r

s i m i l a r

e x p e r i m e n t s f o r w h i c h t h e p r i n c i p l e s o f t h e p r e s e n t

i n v e n t i o n w e r e d e r i v e d :

TABLE

S u s p e n s i o n P o l y m e r i z a t i o n o f

A n

A q u e o u s S o l u t i o n

o f S o d i u m

A c r y l a t e

1 . R e a c t i o n C o n d i t i o n s

S o d i u m _ Catalyst Reaction

Page 4: Us 4255545

7/17/2019 Us 4255545

http://slidepdf.com/reader/full/us-4255545 4/5

4 , 2 5 5 , 5 4 5

3

TABLE-continued

S u s p e n s i o n P o ly m e r i z a t i o n

o f A n

A q u e o u s

S o l u t i o n o f

S o d i u m

A c r y l a t e

Exp. No. PMMA Acrylate

BOM

°C.“

Time Hrs.

212 0 . 5 3 4 . 6 0 . 1 3 60

3

2 2 1

1 . 0 7 4 . 6 0 . 1 3

6 0

3

2 2 4

1 . 6 2 4 . 6

0 . 1 3

6 0

3

242' 0 . 5 3 4 . 6 0 . 1 3 60 3

2 3 6 '

1 . 0 7

4 . 6

0 . 1 3

60 3

2 4 6 ’

1 . 6 7

4 . 6

0 . 1 3

6 0 3

254 1 . 0 7 4 . 6 0.10

.

60 3v

2 5 2 1 . 0 7 4 . 6 1 . 0 40 3

250 1 . 0 7 4 . 6 2 . 0 40 3

2 4 8

1 . 0 7

4 . 6 0 . 4 0 5 0

3

2 5 1 1 . 0 7 4 . 6 0 . 5 0

5 0

3

2 5 3

1 . 0 7

4 . 6 0 . 0 5 0 7 0 3

2 4 9

1 . 0 7 4 . 6

0 . 0 6 2 5 7 0 3

252

1 . 0 7

4 . 6

1 . 0

40

3

2 6 1 1 . 0 7

8 . 0

1 . 0 40 3

2 6 2

1 . 0 7 1 0 . 8

1 . 0

4 0 _ 3

265

1 . 0 7 ‘ 1 2 . 9

1 . 0

40 . 3 ‘

266

1 . 0 7 1 2 . 9 1 . 0

4 0 6

270 1 . 0 7 1 2 . 9

1 . 5

40 6

2 7 1 1 . 0 7 1 2 . 9 0 . 1 5 40 6

2 7 3 1 . 0 7 1 2 . 9 0 . 5

40 6

2 . Product

Y i e l d B e a d mm

E x p . N0. BOM F o rm I . V . 2 . 5 1 . 0 0 . 5 0 . 5

2 12 120 A 1 3 . 5 100 0 0

2 2 1 1 1 2 . 5

D

1 4 . 0 6 6 7

27 0

2 24 127.5

A

9.0 1 0 0

0

. 0

24 2 1 2 0 A 11.0 9 6 3 1

236

1 2 3 . 6

A

9 . 6 9 s

1 1

246 122.5 A 1 1 . 2 9 4 4 . 2

254 1 2 1 D/A 1 3 . 1 3 6 40 2 3

0

2 5 2

1 1 1 . 5 D

1 0 . 0

3 s

8 4 4

250 1 1 5 . 5 D 7 . 8 o

7 8 8

5

24 8

1 0 9 D

1 3 . 1

<

5 5 o

-

45

0

2 5 1

1 2 2 . 5 D 1 4 . 3

3 6 3 a 2 5

1

2 5 3 1 2 7

D/A 9 . 6

9 5 5 0

0

249

1 2 2

D

8 . 5

8 3

1 6 1

0

2 5 2 1 1 1 . 5 D

1 0 . 0

3 a s 4 4 '

2 6 1 1 2 0 . 0 D 1 0 . 2 9 3 5 3 5 1

262

1 1 3 . 0 D 1 1 . 5

4

5 2 44 1

2 6 5

_

114.0 A 5.8

47

3 7 1 5 1

266 4 5

D 1 1 . 7

8 1 5 1

40

270 5 2

D 1 3 . 4 7 2

1 3

3 6 2 a

2 7 1 1 2 5 D 1 3 . 2 3 3 9 1 3

2 7 3 1 1 2 D

1 5 . 9

5 1 6 v74 6

‘ A l l r e a c t i o n s a g i t a t e d at 400 RPM

x c e p t

' wh ic h wer e 800 RPM

P l u s

or minus 2 '

PMMA = o l y m e t h y l

m e t h a c r y l a t e ;

w e i g h t

i l p h a s e

BOM = Based

on

monomer

A=

gg r e g a t e

D =

iscr ete

R e f e r r i n g

t o

t h e t a b u l a t e d v d a t a , c o n s i s t e n t

a g g r e g a

t i o n under

N o s .

2 4 2 , 236

and

2 4 6 can be

e x p l a i n e d a s

c a u s e d

by

e x c e s s i v e

a g i t a t i o n

( 8 0 0

RPM

. 4 0 0 R P M )

a n d

c o n s e q u e n t h i g h r a t e o f c o l l i s i o n

a m o n g s t t h e

p o l y

mer a r t i c l e s , c o n t r a r y t o t h e e x p e c t a t i o n t h a t

a g i t a t i o n

would

e n c o u r a g e t h e f o r m a t i o n o f s m a l l e r p a r t i c l e s .

The e a r l i e s t e x p e r i m e n t s ( 2 1 2 , 2 2 1 ,

2 2 4 )

e s t a b l i s h e d

t h a t

t h e

optimum

c o n c e n t r a t i o n

o f

p r o t e c t i v e

c o l l o i d

(PMMA) a s a l i t t l e

over

one p e r c e n t

by

w e i g h t , b a s e d

on t h e

w e i g h t

o f t h e o i l p h a s e .

T h i s

a g a i n was

c o n t r a r y

t o t h e

e x p e c t a t i o n

t h a t mo re

c o l l o i d

w o u l d r e s u l t i n

s m a l l e r p a r t i c l e s

o f p o l y m e r .

I n a l l s u b s e q u e n t e x p e r i

ments t h e c o n c e n t r a t i o n

o f

p r o t e c t i v e c o l l o i d w a s

t h e r e

fo re

m a i n t a i n e d

a t 1 . 0 7 .

E x p .

N o .

2 2 1

r e s u l t e d i n t h e d e s i r e d d i s c r e t e p o l y m e r

p a r t i c l e s r a t h e r

t h a n

c l u m p s o f p a r t i c l e s ( a g g r e g a t e s )

b u t t h e p r e f e r e n c e i s

f o r

a m a j o r i t y

o f

t h e

p a r t i c l e

s i z e i n

t h e o n e - h a l f

t o one m i l l i m e t e r s i z e , t h a t i s n o t l e s s t h a n

one -ha lf mm.

n o r

more t h a n o n e

mm.,

a

criterion

no t

met by

No. 2 2 1 . A l s o ,

we

w a nt

a m o l e c u l a r

weight

e q u i v a l e n t

t o n o t l e s s t h a n a b o u t

t e n

I . V . The

p r e f e r r e d

5 .

1 0

20

2 5

3 0

3 5

45

6 5

4

p a r t i c l e s i z e r e p r e s e n t s

e a s e

i n d i s s o l v i n g

t h e

b e a d s i n

w a t e r

f o r

? e l d

u s e and t h e l o w e r

l i m i t o f

molecular

w e i g h t i s r e l a t e d t o t h e

c o m m e r c i a l

e f f e c t i v e n e s s

o f

t h e

p o l y m e r .

A o w e r temperature ( 5 0 ° ) and l e s s

c a t a l y s t r e s u lt e d

i n

a mo re

f a v o r a b l e p a r t i c l e

s i z e

d i s t r i b u t i o n and

a c c e p t

a b l e

m o l e c u l a r

w e i g h t ,

No.

2 4 8 ,

b u t w i t h

a

l i t t l e

mo re

c a t a l y s t

( N o .

2 5 1 ) some a g g r e g a t i o n w a s

e n c o u n e r e d .

A o n s i d e r a b l y h i g h e r

t e m p e r a t u r e o f

7 0 ° C . ( N o . 2 4 9

and

2 5 3 ) r e s u l t e d

i n a d i s a d v a n t a g e o u s s h i f t t o t h e

h i g h e r

p a r t i c l e

s i z e

a n d l o w e r m o l e c u l a r w e i g h t .

An

even lower t e m p e r a t u r e ( N o . 2 5 2 a t 4 0 °

C . )

r e

s u l t e d i n t h e d e s i r e d p a r t i c l e

s i z e d i s t r i b u t i o n and

t h e

molecular weight

w a s a c c e p t a b l e ;

n o t e

t h a t m o r e c a t a

l y s t

( N 0 .

2 5 0 )

d i d n o t i m p r o v e ‘

t h e p r od u c t .

T h u s ,

e x p e r i m e n t N o s . 2 4 8 a n d

2 5 2 ( a t 5 0 °

a n d

4 0 ° ,

r e s p e c t i v e l y ) p r o d u c e d t h e d e s i r e d

d i s c r e t e , h i g h mo

l e c u l a r w e i g h t p o l y m e r i n a s a t i s f a c t o r y p a r t i c l e s i z e

d i s t r i b u t i o n

but t h i s

w a s

ach i eve d a t a l o w l o a d i n g ,

y i e l d i n g o n l y 4 . 6 %

p o l y m e r ( t h e o r e t i c a l )

b a s e d

o n t h e

t o t a l

w e i g h t

o f

t h e whole

s y s t e m

i n

t h e

r e a c t o r .

T h e r e f o r e , t h e e f f o r t b e c a me one o f f i n d i n g a

w a y

t o

i m p a r t

more economy

n t e r m s o f r e a c t e d p r o d u c t i n t h e

r e a c t o r

a s

s h o w n by t h e s e q u e n c e N o s . 2 5 2 , 2 6 1 , 2 6 2 and

2 6 5 a t 4 0 °

C .

w h er e

t h e

l o a d i n g

w a s

i n c r e a s e d i n s t e p s

from 4.6% t o 1 2 . 9 % . No e s u l t exceeded t h a t o f No. 252

b y

‘ a n

a p p r e c i a b l e m a r g i n .

T h e

r e a c t i o n t i m e a t 4 0 ° C . w a s i n c r e a s e d f o r r u n s

266

: a n d

2 7 0 . Unreacted m o n o m e r and

a l l

water

w e r e

then

e x t r a c t e d f r o m t h e p o l y m e r

b e a d s

w i t h m e t h a n o l . Thus

i t

w a s

d e t e r m i n e d t h a t t h e y i e l d ( i . e . c o n v e r s i o n o f m o n

omer t o p o l y m e r ) had dropped o f f , and had n o t b e e n

i n c r e a s e d e v e n by

a d d i n g

more c a t a l y s t ( 1 . 5 % BOM n

2 7 0 ) . M o l e c u l a r w e i g h t s

w e r e a d e q u a t e ,

b u t p a r t i c l e

s i z e s w e re b a r e l y

i n

t h e d e s i r e d s i z e

r a n g e

f o r 2 7 0 .

B y s t a g i n g t h e r e c t i o n t i m e a n d

t e m p e r a t u r e ,

two

hours a t

4 0

C . , t w o hours a t

5 0 °

C .

and

t w o hours a t

6 0 °

C . ( N o s .

2 7 1 ,

2 7 3 ) w e a c h i e v e d

d i s c r e t e p a r t i c l e s

o f

s a t i s f a c t o r y

m o l e c ul a r w e i g h t i n

t h e d e s i r e d p a r t i c l e

s i z e

d i s t r i b u t i o n w i t h

a h i g h

y i e l d .

T h u s r e x p e r i m e n t

N o .

2 7 3

r e p r e s e n t s t h e p r e f e r r e d

p r a c t i c e .

Two

o t h e r

p r o t e c t i v e

c o l l o i d s

were t r i e d ,

n a m e l y ,

e t h y l

c e l l u l o s e a n d

e t h y l

h y d r o x y

e t h y l

c e l l u l o s e

d i s

s o l v e d i n

t h e same o i l a s i n t h e

e x p e r i m e n t s a b o v e , b u t

d i s c re t e ‘ b e a d s o f t h e d e s i r e d p a r t i c l e s i z e d i s t r i b u t i o n

could not be o b t a i n e d . We l s o

found

t h e

s a me

unde

s i r e d r e s u l t when t r y i n g t o

p r o d u c e ' t h e

p o l y m e r b y

u s i n g

PMMA t h e e f f e c t i v e p r o t e c t i v e c o l l o i d ) d i s

s o l v e d

i n

t o l u e n e

a l o n e .

We

o

n o t

conclude

from

t h i s

t h a t t h e r e a r e no

e q u i v a l e n t s

t o

t h e system

PMMA/Tol

u e n e - T e t r a c h lo r o e t h y l e n e , b u t we

d o

conclude

t h a t

t h e r e a r e

p r o t e c t i v e c o l l o i d / h y d r o c a r b o n

s o l v e n t s y s

tems

w h i ch

a r e

i n e f f e c t i v e ' f o r o u r

p u r p o s e s .

I t

w i l l

b e

s e e n from t h e f o r e g o i n g t h a t t h e a d v a n t a g e

f o r s t a g i n g

t h e

r e a c t i o n i s

economy

o f

p r o d u c t i o n r e p r e

s e n t e d b y h e a v y

l o a d i n g

o f t h e r e a c t o r ( N o . 2 7 3 ) ,

b u t

i t

s h o u l d be noted t h a t beads which a r e p r e d o m i n a t e l y

d i s c r e t e ,

o f

t h e d e s i r e d

h i g h m o l e c u l a r w e i g h t

a n d

o f

t h e p r e f e r r e d p a r t i c l e

s i z e d i s t r i b u t i o n

c a n b e

o b t a i n e d

o t h e r w i s e , e . g . N o .

2 5 2

( a t 4 0 ° C . )

which s u n s t a g e d .

I n

a n y

e v e n t ,

b o t h s t a g e d a n d u n s t a g e d

r e a c t i o n s

e n a b l e

polymer

b e a d s

p r e d o m i n a t e l y

o f

g r e a t e r

t h a n

0 . 5 mm.

and

n o t m o r e t h a n

1

m m .

( l a r g e s t )

d i a m e t e r

t o

be f 1 l

tered o r s e p a r a t e d

from

t h e

r e a c t i o n

mixture

i n any

p r e f e r r e d w ay

a n d

d r i e d

f o r s h i p m e n t ; a l s o , o n e

p e r c e n t

o r

l e s s r e s i d u a l m o n o m e r

i s f o u n d ,

c h a r a c t e r i z i n g

a

h i g h l y e f ? c i e n t r e a c t i o n . The

c a t a l y s t i s

a f r e e

r a d i c a l

Page 5: Us 4255545

7/17/2019 Us 4255545

http://slidepdf.com/reader/full/us-4255545 5/5

4 , 2 5 5 , 5 4 5

5

c a t a l y s t ,

e . g . Vazo

5 0 w h i c h

i s

2 , 2 ' - a z o b i s - 2 - a m i d i n o

p r o p a n e

h y d r o c h l o r i d e .

The

embodiments

o f

t h e i n v e n t i o n

i n which a n e x c l u

s i v e p r o p e r t y or p r i v i l e g e i s

c l a i m e d

a r e de?ned a s

f o l l o w s :

1 .

A

e t h o d

o f p r o d u c i n g

p o l y s o d i u m

a c r y l a t e

i n

e s s e n t i a l l y d r y

b e a d f o r m

f r e e o f a g g r e g a t e , h a v i n g a

p a r t i c l e

s i z e

d i s t r i b u t i o n

s u c h t h a t t h e

m a j o r i t y

o f

a r t i

c l e s a r e i n t h e range

of

. 5 t o 1

mm .

d i a m e t e r

with

f e w

o f

r e a t e r

t h a n 2 . 5

mm.

r e s s

t h a n 0 . 5 mm . c o m p r i s i n g :

6

p o l y m e r i z i n g a q u e o u s sodium

a c r y l a t e

mo no me r

n

a

body o f h y d r o c a r b o n s o l v e n t i n t h e f o r m o f t o l

u e n e - t e t r a c h l o r o e t h y l e n e

h y d r o c a r b o n

s o l v e n t i n

which

i s

d i s s o l v e d a p r o t e c t i v e c o l l o i d

i n

t h e form

5

o f

p o l y m e t h y l m e t h a c r y l a t e ;

a n d

s e p a r a t i n g

t h e r e s u l t a n t p o l y m e r p a r t i c l e s w h i c h

a r e

e s s e n t i a l l y

f r e e

of water

and

u n r e a c t e d

m o n o

m e r .

2 . A

ethod

a c c o r d i n g

t o c l a i m 1 i n which

p o l y m e r i

1 0

z a t i o n

i s i n s t a g e s : 4 0 ° C .

f o r a b o u t

t w o h o ur s , 5 0 ° C . f o r

a b o u t

t w o hours

and 6 0 °

C .

f o r a b o u t t w o h o u r s .

t t

I

t i

1 5

2 5

3 0

3 5

45

5 5