Perfluoropolyether additives

• US 20040235685A1
• Filed: 05/20/2004
• Published: 11/25/2004
• Est. Priority Date: 05/20/2003
• Status: Active Grant

• Current Assignee: Solvay Solexis SPA (Solvac SA)
• Original Assignee: Solvay Solexis SPA (Solvac SA)
• Inventors: Russo, Antonio, Maccone, Patrizia
• Granted Patent: US 7,399,735 B2
• Time in Patent Office: Days
• US Class Current: 508/266
• CPC Class Codes: C08G 65/007 containing fluorine
• CPC Class Codes: C10M 147/04 Monomer containing carbon, hydrogen, halogen and oxygen
• CPC Class Codes: C10M 169/00 Lubricating compositions characterised by containing as components a mixture of at least two types of ingredient selected from base-materials, thickeners or additives, covered by the preceding groups, each of these compounds being essential
• CPC Class Codes: C10M 169/041 the additives being macromolecular compounds only
• CPC Class Codes: C10M 169/044 the additives being a mixture of non-macromolecular and macromolecular compounds
• CPC Class Codes: C10M 177/00 Special methods of preparation of lubricating compositions; Chemical modification by after-treatment of components or of the whole of a lubricating composition, not covered by other classes
• CPC Class Codes: C10M 2213/043 used as base material
• CPC Class Codes: C10M 2213/0606 used as base material
• CPC Class Codes: C10M 2215/221 Six-membered rings containing nitrogen and carbon only
• CPC Class Codes: C10N 2020/04 Molecular weight; Molecular weight distribution
• CPC Class Codes: C10N 2050/10 Semi-solids; greasy

Abstract

Compounds formed of (per)fluoropolyether chains and end groups having a pyridine structure, with structural formula:

T₁-CW₁—O—R_f—CW₂-T₂   (I)

wherein

T₁, T₂, equal to or different from each other, have the following meanings:

F, CF₃, C₂F₅, (C₂F₄)Cl;

CH₂—B—Y, CH(CF₃)O—Y, wherein:

B═O, S;

wherein R₁, R₂, R₃, R₄, equal to or different from each other, are H, F, C₁-C₈ linear or branched perfluoroalkyl, NO₂, CN;

with the proviso that at least one of the two end groups T₁, T₂ is CH₂—B—Y or CH(CF₃)O—Y as above defined;

W₁, W₂, equal to or different from each other, are —F, —CF₃;

Rf is a (per)fluoropolyoxyalkylene chain having a number average molecular weight from 400 to 10,000.

Claims

1. Compounds formed of (per)fluoropolyether chains and end groups having a pyridine structure, having the following structural formula:

T₁—

CW₁—

O—

R₁—

CW₂-T₂  

 

(I)

wherein

T₁, T₂, equal to or different from each other, have the following meanings;

F, CF₃, C₂F₅, (C₂F₄)Cl;

CH₂—

B—

Y, CH(CF₃)O—

Y, wherein;

B═

O, S;

wherein R₁, R₂, R₃, R₄, equal to or different from each other, are H, F, C₁-C₈ linear or branched perfluoroalkyl, NO₂, CN, preferably H and/or C₁-C₈ linear or branched perfluoroalkyl;

with the proviso that at least one of the two end groups T₁, T₂ is CH₂—

B—

Y or CH (CF₃)O—

Y as above defined;

W₁, W₂, equal to or different from each other, are —

F, —

CF₃;

Rf is a (per)fluoropolyoxyalkylene chain formed of one or more repeating units, statistically distributed in the chain, having the following structure;

(CFXO), (CF₂CF₂0), (CF₂CF₂CF₂O), (CF₂CF₂CF₂CF₂O), (CR₅R₆CF₂CF₂O), (CF(CF₃)CF₂O), (CF₂CF(CF₃)O),

wherein X═

F, CF₃;

R₅ and R₆, equal to or different from each other, are selected from H, Cl, perfluoroalkyl from 1 to 4 carbon atoms;

the number average molecular weight of R_f being from 400 to 10,000, preferably from 800 to 5,000.

2. Compounds according to claim 1, wherein the (per)fluoropolyether chain R_f is selected from the following structures:

—

(CF₂CF(CF₃)O)_a(CFXO)_b—

or —

(CF₂CF(CF₃)O)_a(CFXO)_b—

CF₂(R′

_f)CF₂—

O—

(CF₂CF(CF₃)O)_a(CFXO)_b—

 

 

(A)

wherein R′

_f is a fluoroalkylene group from 1 to 4 C atoms;

X is F or CF₃;

a and b are integers such that the number average molecular weight is within the above range;

a/b is between 10 and 100;

—

(CF₂CF₂O)_c(CF₂O)_d(CF₂(CF₂)_zO)_h—

 

 

(B)

wherein c, d and h are inetgers such that the number average molecular weight is within the above range;

c/d is between 0.1 and 10;

h/(c+d) is between 0 and 0.05, z is 2 or 3;

h can also be equal to 0;

—

(CF₂CF(CF₃)O)_e(CF₂CF₂O)_f(CFXO)_g—

 

 

(C)

wherein X is F or CF3;

e, f, g are integers such that the number average molecular weight is within the above range;

e/(f+g) is between 0.1 and 10;

f/g is between 2 and 10;

—

(CF₂(CF₂)_zO)_s—

 

 

(D)

wherein s is an integer such as to give the above molecular weight, z has the already defined meaning;

—

(CR₅R₆CF₂CF₂O)_j′

or —

(CR₅R₆CF₂CF₂O)_p′

—

R′

_f—

O—

(CR₅R₆CF₂CF₂O)_q—

 

 

(E)

wherein R₅ and R₆ are equal to or different from each other and selected from H, Cl or perfluoroalkyl from 1 to 4 C atoms;

R′

_f is a fluoroalkylene group from 1 to 4 C atoms;

j′

, p′ and

q′

are integers such as to have a molecular weight as that above indicated;

—

(CF(CF₃)CF₂O)_j or —

(CF(CF₃)CF₂O)_j—

R′

_f—

O—

(CF(CF₃)CF₂O)_j″

—

 

 

(F)

wherein R′

_f is a fluoroalkylene group from 1 to 4 C atoms;

j″

being an integer such as to give the above molecular weight.

3. Compounds according to claim 2, wherein the perfluoropolyether structures R_f in the compounds of formula (I) are selected from the structures (A) and (B).

4. Compounds according to claim 1, wherein the (per)fluoropolyether chains are linked by an ether function to the carbon atom in alpha position with respect to the nitrogen atom of the pyridine ring Y.

5. Lubricating compositions comprising:

an oil or a grease having a perfluoropolyether structure;

from 0.05% to 10% by weight, preferably from 0.1% to 5% by weight on the total of the composition, of compounds of claim 1.

6. Compositions according to claim 5, wherein the perfluoropolyether oils have structures belonging to the following classes:

E-O—

(CF(CF₃)CF₂O)_m′

(CFXO)_n′

-E′

 

 

(1)

wherein;

X is equal to F or CF₃;

E and E′

, equal to or different from each other, are selected from CF₃, C₂F₅ or C₃F₇;

m′ and

n′

are integers such that the m′

/n′

ratio is between 20 and 1,000 and the product viscosity is between 10 and 4,000 cSt;

the various units are statistically distributed along the chain;

C₃F₇O—

(CF(CF₃)CF₂O)_o′

-D)  

 

(2)

wherein;

D is equal to —

C₂F₅ or —

C₃F₇;

o′

is an integer such that the product viscosity is within the above range;

{C₃F₇O—

(CF(CF₃)CF₂O)_p′

—

CF(CF₃)—

}₂  

 

(3)

wherein;

p′

is an integer such that the compound viscosity is within the above range;

E-O—

(CF(CF₃)CF₂O)_q′

(C₂F₄O)_r′

(CFX)_s′

-E′

 

 

(4)

wherein;

X is equal to F or CF₃;

E and E′

, equal to or different from each other, are as above;

q′

, r′ and

s′

are integers and can also have the 0 value, and such that the product viscosity is within the above range;

E-O—

(C₂F₄O)_t′

(CF₂O)_u′

-E,  

 

(5)

wherein;

E and E′

, equal to or different from each other, are as above;

t′ and

u′

are integers such that the t′

/u′

ratio is between 0.1 and 5 and the product viscosity is within the above range;

E-O—

(CF₂CF₂CF₂O)_v′

-E′

 

 

(6)

wherein;

E and E′

, equal to or different from each other, are as above;

v′

is a number such that the product viscosity is within the above range;

D-O—

(CF₂CF₂O)_z′

-D′

 

 

(7)

wherein;

D and D′

, equal to or different from each other, are selected between C₂F₅ or C₃F₇;

z′

is an integer such that the product viscosity is within the above range;

the perfluoropolyether structures of the classes from (1) to (7) having a viscosity determined at 20°

C. from 30 to 100.000 cSt, preferably from 100 to 2,000 cSt.

7. Compositions according to claim 6, wherein the perfluoropolyether oils are those of the classes (1), (4), (5).

8. Compositions according to claim 5, comprising anti-rust, anti-oxidant or anti-wear additives.

9. Compositions according to claim 5, wherein the grease contains the perfluoropolyether oil and thickeners selected from PTFE, sodium terephthalamate, calcium or lithium soaps, polyurea.

10. Compositions according to claim 9 containing additives selected from dispersing agents preferably surfactants, in particular non ionic, having a perfluoropolyether or perfluoroalkyl structure;

talc or inorganic fillers, anti-rust, anti-oxidant or anti-wear additives.

11. A process to obtain the compounds of claim 1, comprising the following steps:

a) formation of an alcoholate or thiolate, by reaction of a compound having a (per)fluoropolyoxyalkylene structure of formula;

T′

₁-CW₁—

O—

R_f—

CW₂-T′

₂  

 

(II)

wherein;

R_f, W₁ and W₂ have the above meanings;

T′

₁ and T′

₂, equal to or different from each other, represent and end group selected from the following;

CH₂OH, CH₂SH, CH(OH)CF₃, F, CF₃, C₂F₅, (C₂F₄)Cl;

with the proviso that at least one of the two end groups T′

₁ and/or

T′

₂ is equal to CH₂OH, CH₂SH or CH(OH)CF₃;

with an organic or inorganic base, in organic solvent inert under the reaction conditions;

b) reaction of the alcoholate or thiolate obtained in step a) with a pyridine compound of formula

wherein R₁, R₂, R₃, R₄ have the above meaning, Q is halogen selected from Cl, Br, I,

wherein the ratio of the equivalents between the alcoholate or thiolate function of the (per)fluorinated chain and the pyridine compound (III) is from 1 to 0.5, preferably from 0.8 to 0.6, in an organic solvent inert under the reaction conditions, at a temperature in the range 20°

C.-100°

C., preferably 40°

C.-80°

C.;

c) product isolation from the reaction mass by means of the known methods of the prior art.

12. A process according to claim 11, wherein the steps a)+b) can be simultaneously carried out, preferably in the presence of a phase transfer agent;

or they can be carried out in sequence.

13. A process according to claim 12, wherein the phase transfer agent is a phosphonium or a quaternary ammonium salt, preferably selected between tetrabutylammonium hydroxide or tetramethylammonium chloride.

14. A process according to claim 11, wherein, when steps a) and b) are simultaneously carried out, the ratio by weight between the solvent and the (per)fluorinated alcohol or thiol is from 0.5 to 10, preferably from 2 to 5;

the ratio between the base equivalents and the (per)fluorinated alcohol or thiol equivalents ranges from 2 to 10;

the equivalents of the phase transfer agent, when used, are in a ratio with the equivalents of the (per)fluorinated alcohol or thiol from 0.01 to 0.1.

15. A process according to claim 11, wherein, when steps a) and b) are carried out in sequence, the ratio between the base equivalents and those of the compound of structure (II) ranges from 1.1 to 2, preferably from 1.2 to 1.5.

16. Use of the compounds according to claim 1 as stabilizing additives of oils and greases having a perfluoropolyether structure towards Lewis acids, even at high temperatures.