METAL-ORGANIC COMPOUNDS

---

Alkanolamine Silicate Derivatives

J. O. KOEHLER and H. LAMPREY

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National Carbon Research Laboratories, Parma, Ohio

The synthesis and yield of alkanolamine silicates and their derivatives are discussed. These compounds exhibit unique properties such as dispersion and viscosity depression in nonaqueous systems. Tests and results are given for the effect of these properties on resins, rubbers, and paints.

M a n y data have been reported on the synthesis and chemical and physical properties of various organic silicates. Very little information, however, is available on the amino alcohol derivatives of the various silicic acids. Klein and Nienburg (2) prepared alkanolamine esters of orthosilicic acid by heating orthosilicic esters with monoalkanolamines in the presence of water. They observed that these compounds possessed some interesting pharmaceutical properties. A series of di-ieri-butyl diaminoalkyl silicates was prepared and the properties were recorded by DiGiorgio, Sommer, and Whitmore (1), who synthesized these alkanolamine silicates by reaction of di-ieri-butyldichlorosilane with various monoalkanolamines. The physical and chemical properties of the various alkanolamine silicates were studied further by members of this laboratory. One or more of these silicates was expected to possess physical and chemical characteristics of commercial importance. The alkanolamine esters of orthosilicic acid were prepared by the ester interchange method. Tetraethyl orthosilicate was heated with the calculated amount of amino alcohol in the presence of a catalyst. Some of the more basic amino alcohols, such as triethanolamine, required no catalyst to react with the orthosilicate esters. When the alkanolamine and alkyl orthosilicate would not react readily, catalytic amounts of sodium methoxide were added to initiate the reaction. The over-all reaction is represented by the following equation: T

(C H 0) Si + 4HOC H NR -> (R NC H 0) Si + 4C H OH Î 2

5

4

2

4

2

2

2

4

4

2

(1)

5

An alternative method occasionally employed in the preparation of these esters used a dialkoxydichlorosilane in place of the alkyl silicate. This reaction is represented by the following equation: (C H 0) SiCl + 4HOC H NR -> (C H G) Si(OC H NR ) + 2H0C H NR HC1 2

5

2

2

2

4

2

2

5

2

2

4

2 2

2

4

2

(2)

In the authors' experience, the ester interchange method is preferable, as it eliminates thefiltrationstep required in the alternative procedure, and only half as much amino alcohol is needed. The yields of both synthetic methods are good, but in the case of alkanolamine silicates prepared from the polyhydric alkanolamines, the reaction can continue until high polymers are formed (I). 217

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

218

ADVANCES IN CHEMISTRY SERIES OC H I 2

5

—Si—0C H —N—C H —0 2

0C H 2

4

2

4

R

5

I T h e s e c o m p o u n d s a r e v e r y v i s c o u s l i q u i d s o r solids, i f cross l i n k i n g o c c u r s . side

reaction

is possible,

which m a y account f o r a reduction

i n yield:

A second The intra­

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molecular reaction i n E q u a t i o n 3 can occur.

|OC H 2

H|0- u

5

r

Ο—C H —NR 2

C H 0 — S i — 0C H NR 2

R

4

2

I

Ν

4

C H 0—Si—0C H

4

2

4

2

+

4

(3)

2C H 0H+ 2

5

RNC H —Ο 2

4

X H 0|H OC_ H ; 2

4

2

5

II Analytical

data

indicate

that

compounds

of t y p e

I I are formed

during the

reaction of a p o l y h y d r i c alkanolamine a n d e t h y l orthosilicate. T o get t h e m a x i m u m y i e l d o f t h e d e s i r e d a l k a n o l a m i n e s i l i c a t e s ( I I I ) R OC H R I I I H0C H NC H 0—Si—OC H NC H OH 2

2

4

2

5

4

2

OC H 2

4

2

4

5

III t h e r e a c t i o n m u s t b e t e r m i n a t e d as soon as t h e t h e o r e t i c a l a m o u n t is r e m o v e d f r o m t h e r e a c t i o n . of

alcohol

is removed.

of ethyl

I n practice, slightly more t h a n the theoretical

Subsequent

analyses

i n d i c a t e t h a t these p o l y h y d r i c

alcohol amount alkano­

l a m i n e silicates a r e a p p r o x i m a t e l y 90 t o 9 5 % p u r e . I n T a b l e I , a series o f esters p r e p a r e d

f r o m various β-alkylamino alcohols a n d

t e t r a e t h y l o r t h o s i l i c a t e is l i s t e d .

Table I.

Properties of Various Alkanolamine Silicates % Calcd.

Compound ( C H 0 ) Si ( 0 0 Η Ν Η ) ( C H 0 ) Si [OC H4NH(C H40II)l (C H C» Si 1 0 C H N ( C H 4 0 H ) ] (C H 0) Si 10C H4NH(C H )] ( C H 0 ) S i [OC H N(C H5) | ( C H 0 ) S i iOC H N(C4H9)2|2 ( C H 0 ) Si ( O C H N [ C H — C H f C H ) — C H ] ) ( C H 0 ) Si |OC H N[CHfCH ) j )2 (C HBO) Si C O C H N H ( C 6 H j J ( C H 0 j Si [ O C H N ' C H K C H ) ( C H 5 ) ] (C H 0) Si [OC H NH(CH —C H )J (C4H 0) Si [ O C H N ( C H O H ) ] (C H70) Si l O C H N f C H O H ) ] (C H 0) Si [ O C H N ( C H O H ) ] 3 Si [ O C H N ( C H O H ) J ( C H 0 ) Si ( O C H ( C H ) C H N [ C H ( C H ) ] ) ( C H 0 ) Si [ O C H ( C H ) C H N H ] 2

6

2

2

6

2

2

6

2

6

2

B

2

2

6

2

2

2

2

2

2

2

6

2

2

4

2

2

4

2

6

2

2

6

2

2

2

4

4

6

6

4

2

2

2

6

2

6

2

2

4

4

2

2

4

4

2

2

2

2

3

6

4

2

6

2

2

4

2

2

8

2

2

2

4

2

2

9

6

2

4

6

6

2

2

4

5

2

2

2

4

2

2

2

2

2

2

2

2

2

2

2

2

2

4

2

4

4

5

2

2

2

2

2

2

2

4

3

3

2

2

3

2

2

2

9

2

2

ield, % 90 98 100 98 100 92 100 96 96 95 100 96 95 93 94 95 98

B.P.,°C./Mm. 96-97/7.0 —. — 111/2.0 180/7.0 139-140/0.8 — 135/1.0 118/0.3 138/0.2 135/0.3 — —

—

117-118/1.0 110-111/6.0

Si 11.8 8.74 6.76 9.53 7.99 5.94 4.07 6.89 7.18 6.29 6.28 8.65 6.34 5.42 4.52 5.61 10.51

Ν 11.8 8.74 6.76 9.53 7.99 5.94 4.07 6.89 7.18 6.29 6.28 8.65 6.34 8.13 9.04 5.61 10.51

% Found Si 11.40 8.9 6.62 9.36 7.91 5.91 3.98 6.87 7.10 6.28 6.19 8.86 6.21 5.41 4.49 5.58 10.21

Ν 11.45 8.54 6.71 9.42 7.93 5.82 4.01 6.86 7.15 5.98 6.22 8.48 6.19 8.07 8.97 5.42 10.32

A series of quaternary ammonium compounds prepared from dimethyl (triethanolamine) silicate and various fatty acids is listed in Table I I .

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

219

KOEHLER AND LAMPREY—ALKANOLAMINE SILICATE DERIVATIVES Table II.

Diethyldi(triethanolamine)

Silicate-N,N-Dicarboxylates % Found

% Calcd. Si and Ν 3.44 3.02 2.85 2.86 2.77 2.87 2.87

Carboxylic Acid Laurie Palmitic Stearic Oleic Ricinoleic Linoleic Eleostearic

Si 3.41 3.01 2.79 2.81 2.67 2.79 2.81

Ν 3.39 2.99 2.82 2.85 2.71 2.86 2.84

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Synthesis of Compounds A l l m a t e r i a l s were s h o w n t o b e o f a c c e p t a b l e p u r i t y before use. T h e t e t r a e t h y l orthosilicate a n d t h e various β-amino alcohols were s u p p l i e d b y U n i o n C a r b i d e C h e m i c a l s C o . T h e y were checked f o r p u r i t y b y distilling t h r o u g h a 30-plate O l d e r s h a w c o l u m n a n d were s u i t a b l e f o r use w i t h o u t f u r t h e r p u r i f i c a t i o n . T h e f a t t y a c i d s were o b t a i n e d i n t h e p u r e s t state a v a i l a b l e a n d w e r e n o t p u r i f i e d f u r t h e r . Diethoxydi(jg-diethylaminoethyl) Silicate. A r o u n d - b o t t o m e d flask ( 5 l i t e r s ) , fitted w i t h a S t a r k a n d D e a n t r a p ( A c e Glass, Inc., V i n e l a n d , N . J . ) a n d a reflux c o n ­ denser e q u i p p e d w i t h a c a l c i u m c h l o r i d e d r y i n g t u b e , w a s u s e d . I n i,his were p l a c e d 238.9 g r a m s (2.04 m o l e s ) o f β - d i e t h y l a m i n o e t h a n o l a n d 212.5 g r a m s (5.02 m o l e s ) o f t e t r a e t h y l o r t h o s i l i c a t e . A f e w b o i l i n g c h i p s were a d d e d , a n d t h e m i x t u r e w a s h e a t e d u n t i l e t h y l a l c o h o l ceased t o b e e v o l v e d . T h e flask a n d i t s c o n t e n t s w e r e c o o l e d t o room temperature a n d then attached to a vacuum distillation system. T h e residual e t h y l a l c o h o l w a s r e m o v e d u n d e r v a c u u m a t r o o m t e m p e r a t u r e . T h e c r u d e ester w a s p u r i f i e d b y v a c u u m d i s t i l l a t i o n . A colorless f r a c t i o n of t h e p u r e ester b o i l i n g a t 160° to 162°C. a t 7 m m . under a nitrogen atmosphere was obtained. T h i s :raction weighed 340 g r a m s ( 9 5 % o f t h e t h e o r e t i c a l a m o u n t ) . Diethyldi(jg-aminoethyl) Silicate. A t h r e e - n e c k e d flask (1 l i t e r ) , f i t t e d w i t h a T r u b o r e stirrer, a d r o p p i n g funnel, a n d a reflux condenser e q u i p p e d w i t h a c a l c i u m c h l o r i d e d r y i n g t u b e , w a s u s e d . I n i t were p l a c e d 189 g r a m s (1 m c l e ) of d i e t h o x y d i c h l o r o s i l a n e a n d 300 moles of d r y benzene. T h e flask w a s i m m e r s e d i n a n i c e b a t h , a n d t h e c o n t e n t s were c o o l e d t o 5 ° C . T h e s t i r r e r w a s s t a r t e d , a n d 3 0 5 g r a m s ( 5 m o l e s ) o f m o n o e t h a n o l a m i n e were a d d e d d r o p wise a t s u c h a r a t e t h a t t h e t e m p e r a t u r e d i d n o t rise a b o v e 2 0 ° C . W h e n t h e l a s t of t h e a m i n o a l c o h o l w a s a d d e d , t h e ice b a t h w a s r e p l a c e d b y a h e a t i n g m a n t l e , a n d t h e flask w a s h e a t e d t o t h e re l u x t e m p e r a t u r e of benzene f o r 1 h o u r t o c o m p l e t e t h e r e a c t i o n . T h e flask w a s c o o l e d i n d t h e c o n t e n t s were f i l t e r e d t o r e m o v e t h e m o n o e t h a n o l a m i n e h y d r o c h l o r i d e f o r m e d d u r i n g t h e r e a c t i o n . T h e filter c a k e w a s w a s h e d t w i c e w i t h t w o 1 0 0 - m l . p o r t i o n s o f benzene, a n d t h e w a s h i n g s were a d d e d t o t h e f i l t r a t e . T h e f i l t r a t e w a s v a c u u m s t r i p p e d t o r e m o v e t h e benzene a n d excess m o n o e t h a n o l a m i n e . T h e c r u d e ester w a s v a c u u m d i s t i l l e d u n d e r a n i t r o g e n a t m o s p h e r e f o r p u r i f i c a t i o n . T h e p u r e ester b o i l i n g a t 9 6 ° t o 9 7 ° C . at 7 m m . w e i g h e d 214 g r a m s ( 9 0 % o f t h e t h e o r e t i c a l a m o u n t ) .

Viscosity Characteristics in Nonaqueous Systems T h e a l k a n o l a m i n e silicates a n d t h e i r q u a t e r n a r y d e r i v a t i v e s w i t h t h e f a t t y a c i d s exhibit viscosity-depressant properties i n nonaqueous

systems.

The.se c h a r a c t e r i s t i c s

a r e e x e m p l i f i e d b y t h e effects o n t h e v i s c o s i t y o f suspensions o f c a r b o n i n k e r o s i n e and

o f resins ( T a b l e s I I I a n d I V ) . Table

III.

Viscosity

of

1 to 1 Carbon-Kerosine

Mixti r e

a

Containing Various Alkanolamine Silicates Required to Extrude 10 C c . of Mixture through Rheometer Silicate Blank ( C H 0 ) Si (C4H 0) Si (C H 0) Si (C H 0) Si 2

6

2

2

6

2

2

6

2

9

2

Concn., %

[ O C H N ( C H O H ) ] · 2HOCnH 3 [OC H N(C2H40H) ]2 · 2 H O C n H [ O C 2 H N i C 2 H ) ] · 2HOCnH 5 [OCH(CH3)CH NCH(CH ) ] ·2Η0 ΟΗπΗ3 2

2

4

2

4

2

4

2

3

3 5

2

4

5

2

3

2

2

3

2

2

2

3

— 1 1 1 1

Time, sec. 545.0 2.5 3.9 10.5 5.6

Pressure, p.s.i.g. 2 0 0 0 0

«Carbon was Thermax, 0.25 to 0.5 micron (Thermatonic Carbon Co., New York, Ν. Y . ) .

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

220

ADVANCES IN CHEMISTRY SERIES

Table IV.

Effect of Alkanolamine Silicates on Resin Viscosities Viscosity at 27° C , Centipoises

Resin Type Epoxy Phenolic Styrene Styrene acrylate α

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6

No additive 8000 800 340 7540

1% A« 6000 500 300 4500

1% B*> 6000 560 260 3900

A is diethyldi(triethanolamine) silicate. Β is dibutyldi(triethanolaminej silicate.

Effects in Resins. Besides the viscosity effects cited above, these silicate materials affect the flow characteristics of resins. Both the extrudability and injection molding characteristics are improved by the addition of the silicates. The data obtained from these tests are shown in Tables V and VI and Figure 1. Two filled resins, one a vinyl and the other a phenolic, were tested by the following procedure. The vinyl resin was ground (through 10 mesh) with a Wiley rotary knife mill (Arthur H. Thomas Co.). Samples were prepared by adding 0.5 gram of each additive to separate 50-gram portions of the milled resin, followed by mixing with a mortar and pestle. Additional mixing occurred when the test specimens were injection molded at 325°F. to make preformed slugs % inch in diameter and 1 inch in length for use in the flow measuring apparatus. The phenolic resin samples were prepared by adding 0.5 gram of each silicate to separate 50-gram portions of the resin, followed by mixing with a mortar and pestle. Test specimens % inch in diameter and 1 inch in length were preformed at room temperature and a pressure of 10,000 p.s.i. The apparatus for the flow tests is a constant force, vertical-orifice machine consisting essentially of the orifice, block, charge chamber, ram, and pressure system. A split cone containing a vertical orifice % inch in diameter and 2*4 inches in length is clamped into a steam-heated block. Within the block, below the orifice and con­ centric with it, is the charge chamber which is % inch in diameter and 2 inches in length. The ram is so arranged that it applies pressure to the charge chamber from

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

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KOEHLER AND LAMPREY—ALKANOLAMINE SILICATE DERIVATIVES

221

t h e b o t t o m , f o r c i n g t h e m a t e r i a l u p i n t o t h e orifice. V a r i a b l e p r e s s u r e i s a p p l i e d t o the r a m b y a mechanical system. H e a t is supplied b y steam passing t h r o u g h a reduc­ ing valve a n d into the block. T h e temperature is controlled b y regulating the steam pressure. T h e v i n y l resin specimens a t r o o m t e m p e r a t u r e were inserted i n a h o t charge chamber a t 300°F. a n d tested immediately. A p r e s s u r e o f 1400 p . s . i . w a s a p p l i e d a n d the t i m e r was started. T h e time required for the extrusion of t h e resin t o the t o p of t h e d i e (2^4 inches i n l e n g t h ) a n d f o r % i n c h i n t e r v a l s t h e r e a f t e r w a s r e c o r d e d (Figure 1 ) . T h e phenolic resin specimens a t r o o m temperature were inserted i n the hot charge c h a m b e r a t 2 7 5 ° F . a n d t e s t e d i m m e d i a t e l y . A p r e s s u r e o f 1400 p . s . i . w a s a p p l i e d a n d the timer was started. A f t e r 2 minutes, the length of the extruded resin was measured. A t the end of this time t h e resin w i t h i n the charge was cured t o a solid mass (Table V ) .

Table V.

Length of Phenolic Resin Extruded

Additive, 1% Blank Diethyldi(triethanolamine) silicate Diethyldi (triethanolamine) silicate-iV-oleate Diethyldi (triethanolamine) silicate-iV.iV-dioleate

Mean Length, Inches 2.34 2.59 2.64 2.82

T h r e e resins p o l y s t y r e n e , E t h o c e l ( D o w ) , a n d V i n y l i t e U G - 1 8 0 0 (Bakélite C o . ) w e r e tested t o d e t e r m i n e t h e effect of t h e a l k a n o l a m i n e s i l i c a t e o n t h e i r i n j e c t i o n m o l d i n g characteristics. A V a n D o r n injection molding machine ( T h e V a n D o r n I r o n W o r k s C o . , C l e v e l a n d , O h i o ) a n d a s t a n d a r d die w e r e e m p l o y e d i n t e s t i n g these resins. T h e temperature of t h e m u d cylinder was held constant a n d t h e pressure o n the r a m head was v a r i e d . T h e results a r e shown i n T a b l e V I .

Table VI.

Effect of Diethyldi(triethanolamine) Silicate-N,N-Dioleate on Injection Molding Characteristics of Resins

Resin Polystyrene

Concn. of Silicate, % 0 1 0 1 0 1

Ethocel Vinylite

Effects i n R u b b e r . compounding

Molding Temp., °F. 375 375 375 375 325 325

Pressure Required to Fill Mold in 1 M i n . , P.S.I.G. 500 400 525 400 600 475

T h e alkanolamine silicate exhibit a pronounced

a n d c u r i n g of rubber.

Tests

were m a d e o n rubber

effect o n t h e

stocks

containing

the compositions given i n T a b l e V I I .

Table VII. Ingredient Smoked sheet M . P. C . channel black Stearic acid Alkanolamine silicate

Composition of Test Rubber Stocks Blank* 100 500 — —

Control 100 50 4 —

Experimental 100 50 — 4

° Parts by weight.

T h e silicates a n d s m o k e d sheets o f n a t u r a l r u b b e r w e r e m i x e d i n a B a n b u r y m i x e r ( F a r r e l - B i r m i n g h a m C o . , A n s o n i a , C o n n . ) f o r 6 h o u r s a t 1 4 5 ° F . T h e n h a l f of the channel black was added t o the rubber-dispersant m i x t u r e a n d m i x i n g was con­ tinued f o r 2 hours. T h e rest o f t h e c h a n n e l b l a c k w a s a d d e d a n d m i x i n g w a s continued 4 hours longer. T h e stock was d u m p e d a t the e n d of the 1 2 - h o u r m i x i n g cycle. T h e stock d u m p i n g temperature a n d the total power consumption d u r i n g the m i x i n g operation are tabulated i n T a b l e V I I I . F r o m t h e B a n b u r y m i x i n g d a t a , a l l t h e s t o c k c o n t a i n i n g t h e silicates c o n s u m e less p o w e r t h a n t h e b l a n k . T w o o f t h e s t o c k s , N o s . 3 a n d 5, s h o w v e r y l o w p o w e r c o n ­ sumptions, m u c h lower t h a n stearic acid, w h i c h m a y indicate h i g h l u b r i c i t y a n d good tubing qualities.

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

ADVANCES IN CHEMISTRY SERIES

222

Table VIII.

Banbury M i x i n g , Surface, a n d Extrusion Data

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Stock No. Additive 1 Blank 2 Control (stearic acid) 3 Diethyldi (triethanolamine) silicate-iV, iV-dioleate 4 Diethyldi (triethanolamine) silicate^-iV, iV-distearate 5 Dibutyldi (triethanolamine) silicate-iV, iV-dioleate 6 Diethyldi (triethanolamine) silicate-iV-oleate 7 Diethyldi (triethanolamine) silicate

Stock Dumping Temp., °F. 260 256

Power Consumed, Surface Watt/Hr. Bloom None 676 550 Considerable

Length Weight Extruded Extruded, G. Feet Inches 14 450 15 448 13 6

Stock Tack Slight None

259

492

None

Slight

453

15

1

256

524

Slight

None

449

14

1

260

501

None

Considerable

456

14

5

259

588

None

Considerable

435

13

9

—

None

V. slight

446

14

0

258

T h e B a n b u r y m i x e d s t o c k s were sheeted off t h e l a b o r a t o r y m i l l a f t e r a 3 - m i n u t e blending period a n d observed after 48 hours ( T a b l e V I I I ) . A l l stocks h a d good general appearance, except N o . 2 w h i c h was poor, a n d good visual q u a l i t y of dispersion. O n l y stock 4 showed a n y surface b l o o m . S t o c k s 3 a n d 7 e x h i b i t e d t h e m o s t desirable tack. W h e n t h e sheets were off t h e m i l l 4 8 h o u r s , t h e s t o c k s were r e w a r m e d o n t h e l a b o r a t o r y m i l l a n d extruded t h r o u g h a G a r v e y die ( G . R . G a r v e y & Sons, H a m m o n t o n , N . J . ) . T h e tube temperature was 1 8 0 ° C , t h e screw speed w a s 4 5 r.p.m., and the time of extrusion was 1 minute. T h e extrusion data are tabulated i n T a b l e V I I I . A l l s t o c k s w e r e m o r e effective t h a n s t e a r i c a c i d as a l u b r i c a n t , as i n d i c a t e d b y t h e g r e a t e r l e n g t h e x t r u d e d . S t o c k 3 w a s c o n s i d e r a b l y m o r e effective t h a n s t e a r i c a c i d as a d i e l u b r i c a n t . M o o n e y p l a s t i c i t y tests i n d i c a t e d t h a t n o n e o f t h e s i l i c a t e s h a d a n y s o f t e n i n g a c t i o n o n r u b b e r a n d t h a t t h e silicates a r e e s s e n t i a l l y l u b r i c a n t s a n d n o t p l a s t i c i z e r s f o r rubber. T h e first t h r e e s t o c k s , t h e b l a n k , s t e a r i c a c i d , a n d s t o c k 3 , were c u r e d t o c o m p a r e t h e p h y s i c a l p r o p e r t i e s of t h e s t o c k s . T h e e x p e r i m e n t a l s t o c k s were t a k e n a n d m i x e d w i t h the ingredients i n Table I X .

Table IX.

Ingredients for Cured Rubber Stocks Parts by Weight 154.00 5.00 1.00 3.00 3.00 0.75

Ingredient Experimental material Zinc oxide BLE" Pine tar oil Sulfur Mercaptobenzothiazole

Antioxidant for rubber (Naugatuck Chem­ ical Division of TJ. S. Rubber C o . , Naugatuck, Conn.). α

T h e s t o c k s were c u r e d a t 2 7 4 ° F . f o r v a r y i n g l e n g t h s o f t i m e . m e a s u r e d d u r i n g t h i s test a r e t a b u l a t e d i n T a b l e X .

Table X. Time of Cure, Stock Min. Blank 20 Control (stearic acid) 30 45 60 90 No. 3 20 30 45 60 90

T h e physical properties

Physical Properties of Cured Rubber Stocks Modulus 300% 795 1080 1330 1530 1810 1180 1390 1550 1620 1700

500% 2050 2630 2050 3330 3650 2850 3090 3340 3370 3420

Tensile, P.S.I. 3775 4180 4450 4450 4490 4490 4470 4480 4320 4290

%

Elong. 695 670 655 625 585 665 650 625 605 595

%

Set 34 44 49 51 50 50 55 55 56 54

Shore Hardness 56 60 64 65 68 64 67 70 70 70

° Temperature at which a specimen of rubber first becomes taut between the clamps.

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

Stock Gravity 1.131 1.131

1.138

T-50* + 13.1 +6.7 -0.4 -5.3 -12.5 + 1.0 -3.3 -8.8 -12.3 -14.2

223

KOEHLER AND LAMPREY—ALKANOLAMINE SILICATE DERIVATIVES

T h e d a t a i n T a b l e X s h o w t h a t s i l i c a t e 3 h a s g r e a t e r a c t i v a t i o n t h a n stearic a c i d a n d d e v e l o p s e q u a l l y as g o o d m a x i m u m p h y s i c a l p r o p e r t i e s . S i l i c a t e 3 i s m u c h faster i n c u r i n g t h a n t h e b l a n k . W i t h as m u c h a c t i v a t i o n as i s s h o w n b y t h i s s i l i c a t e , t h e o v e r c u r e d p h y s i c a l s h a v e h e l d u p w e l l w i t h n o a p p r e c i a b l e increase i n m o d u l u s o r reduction i n ultimate elongation.

Dispersant Characteristics

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I n n o n a q u e o u s s y s t e m s , t h e a l k a n o l a m i n e silicates a n d t h e i r d e r i v a t i v e s e x h i b i t d i s p e r s a n t effects. T h i s effect i s s h o w n best b y t h e i r a c t i o n o n t h e g r i n d i n g p r o p e r t i e s of v a r i o u s p i g m e n t s i n p a i n t v e h i c l e s . Procedure. D a t a o b t a i n e d w i t h t w o p i g m e n t s i l l u s t r a t e t h e b e h a v i o r of these silicates i n p a i n t s as d i s p e r s a n t s : a n easy g r i n d i n g t i t a n i u m d i o x i d e p i g m e n t , T i t a n o x R A , m a n u f a c t u r e d b y T i t a n i u m P i g m e n t s C o r p . ; a n d a more difficultly dispersible organic pigment, P y r a z a l o n e R e d , m a n u f a c t u r e d b y D u P o n t . F o r the paint vehicle i n these tests, t h e a u t h o r s u s e d a m o d i f i e d a l k y d r e s i n , X A - C 9 9 , m a n u f a c t u r e d b y t h e Sherwin-Williams Co. T h e m e c h a n i c a l m i x e r e m p l o y e d i n t h e d i s p e r s i o n tests w a s t h e S z e g v a r i A t t r i t o r N o . 01 ( U n i o n P r o c e s s C o . , A k r o n 8, O h i o ) . T h i s i n s t r u m e n t i s e s s e n t i a l l y a n a c c e l e r ­ a t e d b a l l m i l l e m p l o y i n g % - i n c h steel b a l l b e a r i n g s as t h e g r i n d i n g elements. The A t ­ t r i t o r was charged w i t h 200 t o 300 m l . of t h e pigment vehicle m i x t u r e , containing 1 % b y w e i g h t o f the d i s p e r s a n t . T h e m i x i n g was s t a r t e d a n d a t 1 0 - m i n u t e i n t e r v a l s a s m a l l s a m p l e was t a k e n f r o m t h e d i s p e r s i o n . T h i s s m a l l s a m p l e was p l a c e d o n a H e g m a n gage ( P r e c i s i o n G a g e & T o o l C o . , D a y t o n , O h i o ) a n d t h e fineness o f g r i n d w a s d e t e r m i n e d . R e s u l t s . T h e fineness v a l u e s o b t a i n e d a r e p l o t t e d a g a i n s t t h e t i m e o f s a m p l e g r i n d i n g . A curve is obtained f o r each p a i n t composition. These experimental data are s h o w n i n F i g u r e s 2 a n d 3 ; each c u r v e represents t h e a v e r a g e o f s e v e r a l tests o n a given paint composition.

_ c σ

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en

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Grinding rate of Titanox-RA in an alkyd resin in the presence of alkanolamine silicates

F i g u r e 2 represents t h e d a t a o b t a i n e d b y d i s p e r s i n g t i t a n i u m d i o x i d e ( T i t a n o x - R A ) i n a n a l k y d r e s i n ( X A - C 9 9 ) . T h e c h a r g e a d d e d t o t h e A t t r i t o r c o n t a i n e d 150 g r a m s of T i t a n o x - R A , 147 g r a m s o f a l k y d r e s i n ( X A - C 9 9 ) , a n d 3 g r a m s o f d i s p e r s a n t . T h e dispersants diethoxydi(triethanolamine) silicate-Af,N-dioleate, diethoxydi(/3-diethylaminoethyl) silicate-Af,N-dioleate, a n d dibutoxydi (triethanolamine) silicate-JV /Vdioleate a r e effective f o r t h i s p i g m e n t - v e h i c l e c o m p o s i t i o n . N o t o n l y d i d t h e silicates g i v e b e t t e r d i s p e r s i o n s , as i n d i c a t e d b y t h e H e g m a n gage r e s u l t s , b u t t h e y also d i s ­ persed the t i t a n i u m dioxide more r a p i d l y i n t h e vehicle. ;J

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.

224

ADVANCES IN CHEMISTRY SERIES

T h e b l a n k , a test s a m p l e c o n t a i n i n g no d i s p e r s a n t , r e q u i r e d 30 m i n u t e s o f g r i n d i n g i n t h e A t t r i t o r t o r e a c h a fineness o f 6.5. T h e s i l i c a t e , a d d e d t o t h e e x t e n t o f 1 p a r t p e r 100 p a r t s o f m i x b y w e i g h t , r e d u c e d t h e g r i n d i n g t i m e t o 2 3 m i n u t e s . This r e d u c t i o n o f 7 m i n u t e s represents a 2 3 % decrease i n t h e o v e r - a l l g r i n d i n g t i m e .

1

ω •I

σ

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o> 4 Φ ^ X in

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20 30 40 50 60 Grinding Time,Minutes

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Figure 3 . G r i n d i n g rate of Pyrazolone Red-Titanox-RA in a n a l k y d resin in the presence of alkanolamine silicates T h e d a t a i n F i g u r e 3 s h o w t h e change i n fineness w i t h g r i n d i n g t i m e o f p a i n t s c o n t a i n i n g 1 0 % o f t h e p i g m e n t as P y r a z a l o n e R e d . T h e p a i n t t e s t e d c o n t a i n e d 108 g r a m s o f T i t a n o x - R A , 12 g r a m s o f P y r a z a l o n e R e d , 177 g r a m s o f a l k y d r e s i n , a n d 3 grams of dispersant. T h e d i s p e r s a n t d i e t h o x y d i ( t r i e t h a n o l a m i n e ) silicate—A^iV-dioleate i s v e r y effective i n d i s p e r s i n g t h e p i g m e n t m i x t u r e i n i t s v e h i c l e . A f t e r 65 m i n u t e s , t h e b l a n k r e a c h e d a fineness o f 6.5, w h i l e t h e p a i n t c o n t a i n i n g t h e s i l i c a t e g a v e a fineness o f 7 a t t h e end of the same g r i n d i n g period. T h e p a i n t sample containing the a d d i t i v e attained a fineness o f 6.5 i n 43 m i n u t e s , whereas t h e b l a n k t o o k 65 m i n u t e s t o r e a c h t h i s s a m p l e fineness. T h i s difference o f 22 m i n u t e s represents a 3 4 % decrease i n t h e g r i n d i n g t i m e . Literature Cited (1) D i G i o r g i o , P. Α., S o m m e r , L. H., W h i t m o r e , F. C . , J. Am. Chem. Soc. 71, 3254-6 (1949). (2) Klein, G . , N i e n b u r g ,H.,G e r m a n P a t e n t 637,532 (Oct. 30, 1936). RECEIVED for review May 10, 1957.

A c c e p t e d J u n e 1, 1957.

METAL-ORGANIC COMPOUNDS Advances in Chemistry; American Chemical Society: Washington, DC, 1959.