U.S. patent application number 12/793757 was filed with the patent office on 2010-09-23 for ether composition.
This patent application is currently assigned to ASAHI GLASS COMPANY, LIMITED. Invention is credited to Kana Ishikawa, Daisuke SHIRAKAWA.
Application Number | 20100240560 12/793757 |
Document ID | / |
Family ID | 40795596 |
Filed Date | 2010-09-23 |
United States Patent
Application |
20100240560 |
Kind Code |
A1 |
SHIRAKAWA; Daisuke ; et
al. |
September 23, 2010 |
ETHER COMPOSITION
Abstract
An ether composition and a lubricant which bond to substrates
with a high bonding ratio and form a coating having a low friction
coefficient surface are provided. An ether composition comprising
at least two compounds selected from (X--).sub.3Y.sup.3,
(X--).sub.2Y.sup.3--Z and X--Y.sup.3(--Z).sub.2 wherein the total
number of moles of CF.sub.3 groups in Z in relation to the sum of
the total number of moles of CF.sub.3 groups in Z and the total
number of moles of OH groups in X is at least 0.001 and at most
0.30. X is
HO--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-Q-,
Y.sup.3 is a perfluoroalkane-triyl group, and Z is
CF.sub.3(CF.sub.2).sub.sO(CF.sub.2CF.sub.2O).sub.g--, wherein a is
an integer of from 0 to 100, b is 0 or 1, s is an integer of from 0
to 19, g is an integer of from 3 to 200, and Q is a polyfluorinated
polymethylene group or a polyfluorinated polymethylene group having
an etheric oxygen atom bonded between carbon-carbon atoms and/or an
etheric oxygen atom bonded to the terminal carbon atom bonded to
Y.sup.3.
Inventors: |
SHIRAKAWA; Daisuke; (Tokyo,
JP) ; Ishikawa; Kana; (Tokyo, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
ASAHI GLASS COMPANY,
LIMITED
Chiyoda-ku
JP
|
Family ID: |
40795596 |
Appl. No.: |
12/793757 |
Filed: |
June 4, 2010 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP08/73225 |
Dec 19, 2008 |
|
|
|
12793757 |
|
|
|
|
Current U.S.
Class: |
508/582 |
Current CPC
Class: |
C08G 2650/48 20130101;
C10N 2030/06 20130101; C08L 71/02 20130101; C10N 2020/071 20200501;
C08G 65/337 20130101; C10N 2020/04 20130101; C10M 2213/04 20130101;
C10N 2040/18 20130101; C10M 147/04 20130101; C10M 107/38 20130101;
C10M 2213/043 20130101; C10N 2050/02 20130101; C08G 65/007
20130101 |
Class at
Publication: |
508/582 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 19, 2007 |
JP |
2007-327619 |
Jul 30, 2008 |
JP |
2008-196370 |
Claims
1. An ether composition comprising at least two compounds selected
from the group consisting of a compound represented by the
following formula (A1), a compound represented by the following
formula (A2) and a compound represented by the following formula
(A3), wherein the total number of moles of CF.sub.3 groups in the
group represented by the following formula (Z) in relation to the
sum of the total number of moles of CF.sub.3 groups in the group
represented by the following formula (Z) and the total number of
moles of OH groups in the group represented by the following
formula (X) (CF.sub.3/(OH+CF.sub.3)) is at least 0.001 and at most
0.30: (X--).sub.3Y.sup.3 (A1), (X--).sub.2Y.sup.3--Z (A2),
X--Y.sup.3(--Z).sub.2 (A3). Wherein X is a group represented by the
following formula (X), Y.sup.3 is a perfluoroalkane-triyl group or
a perfluoroalkane-triyl group having an etheric oxygen atom
inserted between carbon-carbon atoms, provided that when Y.sup.3
has a CF.sub.3 group, the CF.sub.3 group is bonded to a quaternary
carbon,
HO--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-Q-
(X), CF.sub.3(CF.sub.2).sub.sO(CF.sub.2CF.sub.2O).sub.g-- (Z).
Wherein in the above formulae (X) and (Z), a is an integer of from
0 to 100, b is 0 or 1, s is an integer of from 0 to 19, g is an
integer of from 3 to 200, and Q is a polyfluorinated polymethylene
group, a polyfluorinated polymethylene group having an etheric
oxygen atom bonded between carbon-carbon atoms, a polyfluorinated
polymethylene group having an etheric oxygen atom bonded to the
terminal carbon atom bonded to Y.sup.3 or a polyfluorinated
polymethylene group having an etheric oxygen atom bonded between
carbon-carbon atoms and an etheric oxygen atom bonded to the
terminal carbon atom bonded to Y.sup.3.
2. The ether composition according to claim 1, wherein X is a group
selected from the group consisting of a group represented by the
following formula (X1), a group represented by the following
formula (X2), a group represented by the following formula (X3) and
a group represented by the following formula (X4):
HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X1),
HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X2), HOCH.sub.2CH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X3),
HOCH.sub.2CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X4), wherein d is an integer of from 1 to 200.
3. The ether composition according to claim 1, wherein Y.sup.3 is a
group selected from the group consisting of a group represented by
the following formula (Y.sup.3-1), a group represented by the
following formula (Y.sup.3-2) and a group represented by the
following formula (Y.sup.3-3). ##STR00012##
4. The ether composition according to claim 1, wherein the compound
represented by the formula (A1) is a compound represented by the
following formula (A1-1), the compound represented by the formula
(A2) is a compound represented by the following formula (A2-1a), a
compound represented by the following formula (A2-1b) or a
combination of a compound represented by the following formula
(A2-1a) and a compound represented by the following formula
(A2-1b), and the compound represented by the formula (A3) is a
compound represented by the following formula (A3-1a), a compound
represented by the following formula (A3-1b) or a combination of a
compound represented by the following formula (A3-1a) and a
compound represented by the following formula (A3-1b).
##STR00013##
5. The ether composition according to claim 1, wherein the compound
represented by the formula (A1), the compound represented by the
formula (A2) and the compound represented by the formula (A3) have
no --OCF.sub.2O-- structure.
6. The ether composition according to claim 1, wherein the total
amount of the compound represented by the formula (A1), the
compound represented by the formula (A2) and the compound
represented by the formula (A3) is at least 95 mass % in relation
to the ether composition.
7. The ether composition according to claim 1, which has a number
average molecular weight of from 500 to 1,000,000 and a molecular
weight distribution (mass average molecular weight/number average
molecular weight) of from 1.01 to 1.5.
8. A lubricant containing the ether composition as defined in claim
1.
Description
TECHNICAL FIELD
[0001] The present invention relates to an ether composition useful
as a lubricant, etc.
BACKGROUND ART
[0002] A perfluorinated polyether compound (hereinafter referred to
as PFPE) is used as a lubricant, etc. to be applied to the surface
of a magnetic recording medium (Non-Patent Document 1).
[0003] As such a lubricant, PFPE having two CH.sub.2OH groups at
its molecular terminals has been commonly used.
[0004] Further, the present applicant has proposed the following as
PFPE or its composition, which is useful as a lubricant, etc.
[0005] (1) PFPE having three CH.sub.2OH groups, or PFPE having two
CH.sub.2OH groups and one CF.sub.3 group (Patent Document 1).
[0006] (2) An ether composition comprising two types of PFPEs
different in the molecular weight (Patent Document 2).
[0007] In recent years, along with an increase in the recording
density of a magnetic recording medium, narrowing of a space
between a recording element and a magnetic recording medium and a
trend for high speed of rotation of a magnetic recording medium
have been advanced. Accordingly, the application environment of a
lubricant to be applied on the surface of a magnetic recording
medium has been increasingly severe. Therefore, the lubricant is
required to have the following properties.
[0008] (i) It has a high fixative to a magnetic recording medium,
along with the trend for high speed of the magnetic recording
medium.
[0009] (ii) It forms a coating having a low friction coefficient
surface so that when a recording head contacts magnetic recording
media, the impact by the contact is dissipated.
[0010] However, PFPE heretofore proposed did not provide sufficient
performance to meet such requirements. [0011] Non-Patent Document
1: "Monthly TRIBOLOGY", 1995, vol. 99, November issue, p. 37-38
[0012] Patent Document 1: WO2005/068534 [0013] Patent Document 2:
WO2007/013412
DISCLOSURE OF THE INVENTION
Object to be Accomplished by the Invention
[0014] The object of the present invention is to provide an ether
composition which bonds to substrates with a high bonding ratio and
forms a coating having a low friction coefficient surface and a
lubricant containing the ether composition.
Means to Accomplish the Object
[0015] The ether composition of the present invention is an ether
composition comprising at least two compounds selected from the
group consisting of a compound represented by the following formula
(A1), a compound represented by the following formula (A2) and a
compound represented by the following formula (A3), wherein the
total number of moles of CF.sub.3 groups in the group represented
by the following formula (Z) in relation to the sum of the total
number of moles of CF.sub.3 groups in the group represented by the
following formula (Z) and the total number of moles of OH groups in
the group represented by the following formula (X)
(CF.sub.3/(OH+CF.sub.3)) is at least 0.001 and at most 0.30:
(X--).sub.3Y.sup.3 (A1),
(X--).sub.2Y.sup.3--Z (A2),
X--Y.sup.3(--Z).sub.2 (A3).
[0016] Wherein X is a group represented by the following formula
(X),
[0017] Y.sup.3 is a perfluoroalkane-triyl group or a
perfluoroalkane-triyl group having an etheric oxygen atom inserted
between carbon-carbon atoms, provided that when Y.sup.3 has a
CF.sub.3 group, the CF.sub.3 group is bonded to a quaternary
carbon,
[0018] Z is a group represented by the following formula (Z):
HO--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-Q-
(X),
CF.sub.3(CF.sub.2).sub.sO(CF.sub.2CF.sub.2O).sub.g-- (Z).
[0019] Wherein in the above formulae (X) and (Z), a is an integer
of from 0 to 100, b is 0 or 1, s is an integer of from 0 to 19, g
is an integer of from 3 to 200, and Q is a polyfluorinated
polymethylene group, a polyfluorinated polymethylene group having
an etheric oxygen atom bonded between carbon-carbon atoms, a
polyfluorinated polymethylene group having an etheric oxygen atom
bonded to the terminal carbon atom bonded to Y.sup.3 or a
polyfluorinated polymethylene group having an etheric oxygen atom
bonded between carbon-carbon atoms and an etheric oxygen atom
bonded to the terminal carbon atom bonded to Y.sup.3.
[0020] It is preferred that the group (X) is a group selected from
the group consisting of a group represented by the following
formula (X1), a group represented by the following formula (X2), a
group represented by the following formula (X3) and a group
represented by the following formula (X4):
HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X1),
HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X2),
HOCH.sub.2CH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X3),
HOCH.sub.2CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X4),
wherein d is an integer of from 1 to 200.
[0021] It is preferred that Y.sup.3 is a group selected from the
group consisting of a group represented by the following formula
(Y.sup.3-1), a group represented by the following formula
(Y.sup.3-2) and a group represented by the following formula
(Y.sup.3-3).
##STR00001##
[0022] It is preferred that the compound represented by the formula
(A1) is a compound represented by the following formula (A1-1),
that the compound represented by the formula (A2) is a compound
represented by the following formula (A2-1a), a compound
represented by the following formula (A2-1b) or a combination of a
compound represented by the following formula (A2-1a) and a
compound represented by the following formula (A2-1b), and that the
compound represented by the formula (A3) is a compound represented
by the following formula (A3-1a), a compound represented by the
following formula (A3-1b) or a combination of a compound
represented by the following formula (A3-1a) and a compound
represented by the following formula (A3-1b).
##STR00002##
[0023] It is preferred that the compound represented by the formula
(A1), the compound represented by the formula (A2) and the compound
represented by the formula (A3) have no --OCF.sub.2O--
structure.
[0024] It is preferred that the he total amount of the compound
represented by the formula (A1), the compound represented by the
formula (A2) and the compound represented by the formula (A3) is at
least 95 mass % in relation to the ether composition.
[0025] It is preferred that the ether composition has a number
average molecular weight of from 500 to 1,000,000 and a molecular
weight distribution (mass average molecular weight/number average
molecular weight) of from 1.01 to 1.5.
[0026] The ether composition is preferably used to form a lubricant
containing the ether composition.
EFFECTS OF THE INVENTION
[0027] The ether composition of the present invention bonds firmly
to substrates, forms a coating having a surface with a low
coefficient of friction and is useful as a lubricant to be applied
on the surface of magnetic recording media.
BEST MODE FOR CARRYING OUT THE INVENTION
[0028] In this specification, a compound represented by the formula
(A1) is referred to as the compound (A1). Compounds represented by
the other formulae are referred to in the same manner.
[0029] Further, a group represented by the formula (X) is referred
to as the group (X). Groups represented by the other formulae are
referred to in the same manner.
[0030] The ether composition of the present invention is an ether
composition comprising at least two compounds selected from the
compound (A1), the compound (A2) and the compound (A3), and
preferably comprises the compound (A1) and the compound (A2), or
the compounds (A1) to (A3). Each of the compounds (A1) to (A3) in
the ether composition may consist of one or at least two compounds
and preferably consists of one compound.
(X--).sub.3Y.sup.3 (A1),
(X--).sub.2Y.sup.3--Z (A2),
X--Y.sup.3(--Z).sub.2 (A3).
[0031] X is a group (X).
HO--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-Q-
(X).
[0032] The notation of the structure
--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-- means
that when at least one unit is present with respect to each of the
(CH.sub.2CH.sub.2O) unit and the (CH.sub.2CH(OH)CH.sub.2O) unit,
their arrangement is not particularly limited. Namely, in a case
where one unit is present with respect to both units, the unit
which is bonded to the terminal hydroxyl group may be either of
them. Further, the structure
--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b-- may
be a block copolymer or a random copolymer.
[0033] Q is a polyfluorinated polymethylene group, a
polyfluorinated polymethylene group having an etheric oxygen atom
bonded between carbon-carbon atoms, a polyfluorinated polymethylene
group having an etheric oxygen atom bonded to the terminal carbon
atom bonded to Y.sup.3 or a polyfluorinated polymethylene group
having an etheric oxygen atom bonded between carbon-carbon atoms
and an etheric oxygen atom bonded to the terminal carbon atom
bonded to Y.sup.3. The polyfluorinated polymethylene group means a
group having at least two hydrogen atoms in --(CH.sub.2).sub.t--
(wherein t is an integer of at least 2) substituted by fluorine
atoms. Q is preferably a group represented by the formula
--(CH.sub.2).sub.c--CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (wherein
the right hand side terminal of the group is bonded to Y.sup.3, c
is an integer of from 1 to 100, and d is an integer of from 1 to
200).
[0034] a is an integer of from 0 to 100, preferably an integer of
from 0 to 10, more preferably an integer of from 0 to 2,
particularly preferably 0 or 1. When b is 1, a is preferably 0.
[0035] b is preferably 0 or 1.
[0036] The group (X) is preferably a group (X').
HO--(CH.sub.2CH.sub.2O).sub.a.(CH.sub.2CH(OH)CH.sub.2O).sub.b--(CH.sub.2-
).sub.c--CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X'),
[0037] wherein a to d are the same as defined above.
[0038] c is preferably an integer of from 1 to 10, more preferably
1 or 2.
[0039] d is preferably an integer of from 3 to 100, more preferably
from an integer of from 5 to 50.
[0040] When two or more groups (X) are present in one molecule,
they may be the same or different. Groups (X) having different
numbers of structural units may be categorized as the same. For
example, the same groups may have the same d or may be different
only in d. With respect to the numbers other than d, groups (X')
which are different in a, b or c are considered as different
groups. When two or more groups (X) are in the same molecule, it is
preferred that they are the same groups.
[0041] The group (X) is preferably a group (X1), a group (X2), a
group (X3) or a group (X4), and a group (X1) or a group (X2) is
more preferred in view of easy production and stability of the
compounds (A1) to (A3).
HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X1),
HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X2),
HOCH.sub.2CH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d-- (X3),
HOCH.sub.2CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--
(X4).
[0042] Y.sup.3 is a perfluoroalkane-triyl group or a
perfluoroalkane-triyl group having an etheric oxygen atom inserted
between carbon-carbon atoms, and when Y.sup.3 has a CF.sub.3 group,
the CF.sub.3 group is bonded only to a quaternary carbon.
[0043] A perfluoroalkane-triyl group means a trivalent saturated
hydrocarbon group having all hydrogen atoms substituted by fluorine
atoms, and a quaternary carbon atom which is not bonded to a
fluorine atom may be bonded to a CF.sub.3 group.
[0044] Y.sup.3 is restricted to a group having no CF.sub.3 groups
or having only a CF.sub.3 group bonded to a quaternary carbon atom
for the following reason.
[0045] The present inventors studied the effect of the structure of
PFPEs on their low friction coefficient and firm bonding, which are
incompatible with each other, and found that a CF.sub.3 group
bonded to a secondary carbon atom (CF.sub.2) or a tertiary carbon
atom (CF) has a high degree of freedom in the molecule and hence
contributes to decrease in friction coefficient (decrease in
viscosity), while inhibiting firm bonding. Therefore, the present
inventors decided that the proportion of CF.sub.3 groups in an
ether composition should be controlled to attain both a low
friction coefficient and firm bonding and that PFPE should have a
CF.sub.3 group which is present only at the terminal of Z and may
have another CF.sub.3 group attached to a quaternary carbon atom
with a relatively low degree of freedom in Y.sup.3.
[0046] Y.sup.3 may be a group having an etheric oxygen atom
inserted between carbon-carbon atoms. The number of etheric oxygen
atoms, if present, is preferably 1 to 3. Because an etheric oxygen
atom is present between carbon-carbon atoms, no etheric oxygen atom
can be present at the terminal of Y.sup.3 bonded to X or Z. When
Y.sup.3 contains an etheric oxygen atom, it is preferred that
Y.sup.3 contains no --OCF.sub.2O-- structure and has no
--OCF.sub.2-- structure at the terminal bonded to X or Z. Compounds
having neither structure have a remarkably improved chemical
stability.
[0047] Y.sup.3 is preferably a group having no etheric oxygen atom,
particularly preferably a group (Y.sup.3-1), a group (Y.sup.3-2) or
a group (Y.sup.3-3).
##STR00003##
[0048] Z is a group (Z).
CF.sub.3(CF.sub.2).sub.sO(CF.sub.2CF.sub.2O).sub.g-- (Z).
[0049] s is an integer of from 0 to 19, preferably an integer of
from 0 to 15, particularly preferably an integer of from 0 to
5.
[0050] g is an integer of from 3 to 200, preferably an integer of
from 3 to 100, more preferably an integer of from 3 to 70,
particularly preferably an integer of from 5 to 50.
[0051] Groups (Z) in which s is the same are considered to be the
same, irrespective of whether g is the same or different. The
groups (Z) are preferably the same.
[0052] The group (Z) contributes to decrease in friction
coefficient and is preferred to have a certain length in view of
increasing the freedom of the CF.sub.3 group in the molecule. The
group (Z) is preferably a group (Z1), a group (Z2) or a group
(Z3).
CF.sub.3O(CF.sub.2CF.sub.2O).sub.g-- (Z1),
CF.sub.3(CF.sub.2).sub.2O(CF.sub.2CF.sub.2O).sub.g-- (Z2),
CF.sub.3(CF.sub.2).sub.5O(CF.sub.2CF.sub.2O).sub.g-- (Z3).
[0053] Each of the compounds (A1) to (A3) may be a combination of
two or more compounds which preferably have the same Y.sup.3 but
differ in a, b, c or d in the group (X). In the group (X), the
average of a is preferably a positive number of from 0 to 2,
particularly preferably 0. In the group (X'), the average of c is
preferably 1, and the average of d is preferably a positive number
of from 3 to 100. In the group (Z), the average of g is preferably
a positive number of from 3 to 100.
[0054] It is preferred that the compounds (A1) to (A3) have no
--OCF.sub.2O-- structure in view of chemical stability. A compound
having no --OCF.sub.2O-- structure means a compound in which the
presence of the structure cannot be detected by a conventional
analytical means (such as .sup.19F-NMR).
[0055] As the compound (A1), a compound (A11) or a compound (A12)
is preferred.
{HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--}.sub.3Y.sup.3
(A11),
{HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--}.-
sub.3Y.sup.3 (A12).
[0056] As the compound (A2), a compound (A21) or a compound (A22)
is preferred.
{HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--}.sub.2Y.sup.3--(OCF.sub.-
2CF.sub.2).sub.gO(CF.sub.2).sub.SCF.sub.3 (A21),
{HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--}.-
sub.2Y.sup.3--(OCF.sub.2CF.sub.2).sub.gO(CF.sub.2).sub.sCF.sub.3
(A22).
[0057] As the compound (A3), a compound (A31) or a compound (A32)
is preferred.
HOCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--Y.sup.3{--(OCF.sub.2CF.sub-
.2).sub.gO(CF.sub.2).sub.sCF.sub.3}.sub.2 (A31),
HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2CF.sub.2O).sub.d--Y.s-
up.3{--(OCF.sub.2CF.sub.2).sub.gO(CF.sub.2).sub.sCF.sub.3}.sub.2
(A32).
[0058] When Y.sup.3 is the group (Y.sup.3-1), the compound (A1) is
preferably a compound (A1-1), the compound (A2) is preferably a
compound represented by the following formula (A2-1a), a compound
represented by the following formula (A2-1b) or a combination of a
compound represented by the following formula (A2-1a) and a
compound represented by the following formula (A2-1b), and the
compound (A3) is preferably a compound represented by the following
formula (A3-1a), a compound represented by the following formula
(A3-1b) or a combination of a compound represented by the following
formula (A3-1a) and a compound represented by the following formula
(A3-1b).
##STR00004##
[0059] The present inventors found that the friction coefficient
and the bonding ratio vary depending on the proportion of groups
(Z) and therefore decided that the ratio of groups (Z) is within a
specific range. Namely, the total number of moles of CF.sub.3
groups in the group (Z) in relation to the sum of the total number
of moles of CF.sub.3 groups in the group (Z) and the total number
of moles of OH groups in the group (X) (CF.sub.3/(OH+CF.sub.3),
hereinafter referred to as CF.sub.3 ratio) is at least 0.001 and at
most 0.30. CF.sub.3 ratio is preferably at least 0.01 and at most
0.30. By virtue of the CF.sub.3 ratio within a specific range, the
ether composition of the present invention can attain a low
friction coefficient and a high bonding ratio. When the CF.sub.3
ratio in the composition is too high, the effect of lowering the
friction coefficient is not expected, and trouble such bleed out is
aggravated. When the CF.sub.3 ratio is too low, the friction
coefficient becomes large. However, the composition of the present
invention having a low CF.sub.3 ratio and more than two compounds
has such an effect that it is unlikely to adhere to other
substances in contact with it.
[0060] The CF.sub.3 ratio can be determined by identifying the
structures of the compounds in the ether composition and then
measuring their contents, or directly from the ether
composition.
[0061] Specifically speaking, when NMR is used for the
determination, the ether composition is analyzed by .sup.19F-NMR,
and the peak area for CF.sub.3 groups is determined. The chemical
shift of --OCF.sub.3 is observed around -54.0 to -56.0 ppm.
[0062] The number of terminal OH groups is determined from the area
of the peak attributed to the fluorine atoms in CF.sub.2 around -80
to -81.0 ppm in the .sup.19F-NMR spectrum when the terminal groups
are --CF.sub.2CH.sub.2OH, from the area of the peak attributed to
the fluorine atoms in CF.sub.2 around -75.0 to -78.0 ppm in the
.sup.19F-NMR spectrum when the terminal groups are
--CF.sub.2CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH, or from the area of
the peak attributed to the fluorine atoms in CF.sub.2 around -78.0
to -80.0 ppm in the .sup.19F-NMR spectrum when the of terminal
groups are --CF.sub.2CH.sub.2(OCH.sub.2CH.sub.2).sub.gOH.
[0063] The number of terminal OH groups can also be determined by
measuring --OCF.sub.3 by .sup.19F-NMR and .sup.1H-NMR using a
compound having both hydrogen and fluorine atoms such as
bistrifluoromethylbenzene as an internal control.
[0064] For example, it is determined from the area of the peak
attributed to CH.sub.2 around 4.0 to 4.1 ppm in the .sup.1H-NMR
spectrum when the terminal groups are --CF.sub.2CH.sub.2OH, from
the area of the peak attributed to CH.sub.2 next to CF.sub.2 around
3.8 to 4.0 ppm or the area of the prak attributed to CH.sub.2 in
terminal CH.sub.2OH around 3.5 ppm when the terminal groups are
--CF.sub.2CH.sub.2O(CH.sub.2CH.sub.2O).sub.g--H, or from the area
of the peak attributed to CH in CH(OH) around 3.7 to 3.9 ppm.
[0065] In the case of a compound having both
--CH.sub.2CH(OH)CH.sub.2-- and --CH.sub.2CH.sub.2O--, because
.sup.1H-NMR signals to be used for determination of the number of
OH groups overlap, the OH groups attached to these groups are
converted to CF.sub.3C(O)O-- or CH.sub.3C(O)O-- groups etc., and
the number of OH groups is determined from the area of the chemical
shift peak of such a group in the .sup.1H-NMR or .sup.19F-NMR
spectrum.
[0066] Further, in .sup.1H-NMR analysis, the peak attributed to OH
groups can shift and overlap with the zone important for
identification around 3.5 to 3.8 ppm, depending on the measurement
environment (such as pH). Therefore, it is preferred to deutrate
the hydrogen in OH groups by adding a trace amount of a deuterated
solvent (such as heavy water) to a sample to shift the peak
attributed to OH groups so that the peak does not overlap with the
previously mentioned peaks.
[0067] It is preferred that the ether composition of the present
invention does not contain a compound (A4). By not containing the
compound (A4), it is means that the compound (A4) is not contained
at all, or even if present, its content measured by high
performance liquid chromatography (hereinafter referred to as HPLC)
is at most 2.0 mass %.
Y.sup.3(--Z).sub.3 (A4).
[0068] By virtue of the absence of a compound (A4) in the ether
composition of the present invention, it is possible to suppress
bleed out and to provide a lubricant which firmly bonds to a
substrate. It is preferred to remove the compound (A4) from the
ether composition by the purification method mentioned later.
[0069] The total amount of the compounds (A1) to (A3) is preferably
at least 95 mass % in relation to the ether composition, more
preferably at least 98 mass %.
[0070] When the ether composition consists of a compound (A1) and a
compound (A2), the mass ratios (mass %) of the compound (A1) and
the compound (A2) in the ether composition is from 50 to 95 for the
compound (A1) and from 5 to 50 for the compound (A2), preferably
from 60 to 80 for the compound (A1) and from 20 to 40 for the
compound (A2).
[0071] Further, when the ether composition consists of the
compounds (A1) to (A3), the ratios (mass %) of the compound (A1),
the compound (A2) and the compound (A3) in the ether composition
are from 50 to 90 for the compound (A1), from 5 to 50 for the
compound (A2) and from 1 to 25 for the compound (A3), preferably
from 60 to 80 for the compound (A1), from 10 to 20 for the compound
(A2) and from 5 to 10 for the compound (A3).
[0072] The number average molecular weight (hereinafter referred to
as Mn) of the ether composition is preferably from 500 to
1,000,000, more preferably from 500 to 100,000, particularly
preferably from 1,000 to 20,000.
[0073] The molecular weight distribution (hereinafter referred to
as Mw/Mn) of the ether composition is preferably from 1.01 to 1.5,
more preferably from 1.01 to 1.25. Herein, Mw is the mass average
molecular weight.
[0074] When the Mn and the Mw/Mn are within the above ranges, the
ether composition has a low viscosity, contains a small amount of
evaporative components and dissolves homogeneously in a
solvent.
[0075] The Mn can be measured by gel permeation chromatography
(hereinafter referred to as GPC). The Mw/Mn is determined from the
Mn and the Mw measured by GPC.
[0076] The ether composition of the present invention may be
prepared by the following methods.
[0077] Method 1: Prepare and purify the compounds (A1) to (A3)
respectively and formulate them into a composition.
[0078] Method 2: Prepare the compounds (A1) to the compound (A3) so
that the resulting reaction product also contains the other two as
by-products, and purify the reaction product to a certain CF.sub.3
ratio to obtain a composition.
[0079] Method 3: Mix two or more compositions obtained after
purification in the method 2 into a single composition.
[0080] For example, in the method 1, the compound (A1) can be
prepared in accordance with the method disclosed in Patent Document
1, and the compounds (A2) and (A3) can be prepared in accordance
with the method disclosed in Patent Document 1 by carrying out the
reaction by using starting materials for the compounds (A2) and the
compound (A3) instead of the starting material for the compound
(A1).
[0081] In the method 2, a reaction product containing by-products
can be obtained by carrying out a reaction in the same manner as in
the method 1 or under modified reaction conditions. For example, in
a process for preparing the compound (A1) comprising liquid phase
fluorination, under severe reaction conditions, the compounds (A2)
to (A4) having terminal CF.sub.3 groups can be formed by cleavage
of molecular terminals. In liquid phase fluorination, the fluorine
gas concentration in the gas blown into the liquid phase is
preferably from 5.0 to 50 vol %, more preferably from 10 to 30 vol
% in view of suppression of formation of the compound (A4).
[0082] Under certain reaction conditions, the product of the liquid
phase fluorination may contain the compound (A4). If contained, the
compound (A4) is preferred to be removed by purification.
[0083] As a means for the purification, removal of e.g. metal
impurities and anion impurities by an ion adsorbing polymer,
supercritical extraction and column chromatography may be
mentioned, and it is preferred to combine them.
[0084] The ether composition of the present invention may be used
as it is, after addition of other compounds or as an additive for
other compounds.
[0085] The ether composition of the present invention may be used
as it is or in combination with other substances. For example, as a
lubricant containing the ether composition of the present
invention, the composition may be used as it is.
[0086] Further, PFPE other than the compounds (A1) to (A3)
(hereinafter referred to as other PFPE-XX) may be added to the
ether composition. When a PFPE-XX is added to the ether composition
of the present invention, its amount is preferably at most 10 mass
%, more preferably at most 5 mass % in relation to the total amount
of the ether composition (the ether composition of the present
invention and the PFPE-XX) so that the present invention can show
its characteristics sufficiently.
[0087] Further, the ether composition of the present invention may
be added to PFPE-XX. The content of the PFPE-XX is preferably at
most 50 mass %, more preferably at most 30 mass %, in relation to
the total amount of the ether composition. By adding the ether
composition of the present invention to PFPE-XX, it is possible to
adjust the viscosity of the PFPE-XX and improve the bonding of the
PFPE-XX.
[0088] Examples of the PFPE-XX used in combination with the ether
composition of the present invention include PFPEs-XX having a
terminal hydroxyl group and PFPEs-XX having a UV-absorbing terminal
group such as those mentioned below.
<PFPEs-XX having a terminal OH group>
[0089] FOMBLIN Z-DiOL, FOMBLIN Z-TetraOL, DEMNUM SA and the
like.
<PFPEs-XX having a UV-absorbing terminal group>
[0090] FOMBLIN Z-DIAC, FOMBLIN Z-DEAL, FOMBLIN AM2001, FOMBLIN
Z-DISOC, DEMNUM SH, MorescoA20H and the like.
[0091] As another example of PFPE-XX, an ether compound (A.sup.4)
having from 1 to 4 groups (X) and from 0 to 3 groups (Z) and having
at least 4 groups (X) and (Z) in total may be mentioned.
[0092] The ether compound (A.sup.4) is preferably at least one
member selected from a compound (A.sup.41), a compound (A.sup.42),
a compound (A.sup.43) and a compound (A.sup.44).
(X--).sub.4Y.sup.4 (A.sup.41),
(X--).sub.3Y.sup.4--Z (A.sup.42),
(X--).sub.2Y.sup.4(--Z).sub.2 (A.sup.43),
X--Y.sup.4(--Z).sub.3 (A.sup.44).
[0093] X is a group (X), Y4 is a perfluoroalkane-tetrayl group or a
perfluoroalkane-triyl group having an etheric oxygen atom inserted
between carbon-carbon atoms and having no structure of the group
(Z), and Z is a group (Z).
[0094] The group (X) is preferably the group (X1), the group (X2),
the group (X3) or the group (X4), and the group (X1) or the group
(X2) is more preferred in view of the ease of production of the
compounds (A.sup.41) to (A.sup.44) and their stability.
[0095] Y.sup.4 is preferred to have no CF.sub.3 group.
[0096] Y.sup.4 is preferably any one of the groups (Y.sup.4-1) to
(Y.sup.4-4), and the group (Y.sup.4-1) is particularly preferred
because these compounds are easy to synthesize, are chemically
stable and have low crystallinity.
##STR00005##
[0097] When the ether composition of the present invention and a
PFPE-XX are used in combination, the CF.sub.3 ratio in the whole
composition is preferably adjusted to at least 0.001 and at most
0.30 in order for the ether composition of the present invention to
exert its performance. The PFPE-XX is preferred not to contain a
PFPE having only CF.sub.3 groups at the terminals. In this case,
the total number of moles of OH groups covers all the terminal OH
groups, and the total number of moles of CF.sub.3 groups covers all
the CF.sub.3 groups other than those attached to a quaternary
carbon atom. These total numbers of moles can be determined by NMR
as previously described.
[0098] Further, it is preferred to use a PFPE-XX having a number
average molecular weight of from 1,000 to 10,000 as the
PFPE-XX.
[0099] The ether composition of the present invention is preferably
used as a solvent composition by dissolving or dispersing the ether
composition in a solvent.
[0100] The solvent is preferably a perfluoroamine (such as
perfluorotripropylamine or perfluorotributylamine), a
perfluoroalkane (such as Vertrel XF (manufactured by DuPont)) or a
hydrofluoroether (such as AE-3000 (manufactured by Asahi Glass
Company, Limited)), and a hydrofluoroether is more preferred in
view of its low ozone depleting potential.
[0101] The solvent composition may be a solution, a suspension or
an emulsion and is preferably a solution.
[0102] The concentration of the ether composition of the present
invention in the solvent composition is preferably from 0.001 to 50
mass %, more preferably from 0.01 to 20 mass %.
[0103] The solvent composition may contain or may not contain an
additional component other than the ether composition of the
present invention and the solvent (hereinafter referred to
additional component). When the solvent composition is used as a
lubricant, the additional component may be a radical scavenger
(such as X1p (manufactured by Dow Chemicals)) or the like.
[0104] When the solvent composition is used as a surface modifier,
the additional component may be a coupling agent (of a silane,
epoxy, titanium or aluminum type). Such a coupling agent improves
adhesion between a substrate and a coating.
[0105] It is preferred that the solvent composition does not
contain metal ions, anions, water, low molecular weight polar
compounds or the like because otherwise, the solvent composition
would not show the intended performance.
[0106] Ions of metals (such as Na, K, Ca and Al) can form Lewis
acid catalysts with anions which catalyze decomposition of PFPEs.
Anions (of F, Cl, NO.sub.2, NO.sub.3, PO.sub.4, SO.sub.4,
C.sub.2O.sub.4 and the like) and water can corrode the surface of a
substrate. Therefore, the water content of the solvent composition
is preferably at most 2,000 ppm. Low molecular weight polar
compounds (such as alcohols, plasticizers eluted from resins) can
impair the adhesion between a substrate and a coating.
[0107] When the ether composition of the present invention is used
as a lubricant for magnetic disks, it is used in the same manner as
conventional lubricants. For example, it is applied to the surface
of a substrate for a magnetic disk by roll coating casting, dip
coating (dipping), spin coating, water casting, die coating,
Langmuir-Blodgett film formation or vacuum vapor deposition, and
dip coating, spin coating or vacuum vapor deposition is
preferred.
[0108] The substrate may be a NiP-plated substrate (aluminum, glass
or the like) having a primer layer, a recording layer and a carbon
protective layer in this order.
[0109] The carbon protective layer is preferably at most 5.0 mm
thick and preferably has an average surface roughness (Ra) of at
most 2.0 mm.
[0110] After application of a lubricant, a magnetic disk having a
lubricant layer is preferably subjected to adsorption treatment so
that the lubricant is adsorbed onto the surface of the carbon
protective layer.
[0111] The adsorption treatment may be heat treatment, infrared
treatment, UV treatment or plasma treatment, and is preferably heat
treatment or UV treatment, more preferably heat treatment. Further,
after adsorption treatment, the magnetic disk may be washed with a
fluorine-containing solvent for the purpose of removal of
contaminants and an excess of the lubricant.
[0112] The surface of the lubricant coating after the adsorption
treatment has good water repellency enough to keep the inside the
magnetic disk off water and shows good lubricity for a long
time.
[0113] The bonding ratio of the ether composition of the present
invention after adsorption treatment can be at least 60%. It is
preferably at least 65%, particularly preferably at least 70%.
[0114] The contact angle of water (at room temperature) on the
surface of a magnetic disk treated with the ether composition of
the present invention can be at least 80.degree.. It is preferably
at 85.degree..
[0115] The preferred thickness of a coating formed of the ether
composition of the present invention is at most 5.0 nm, more
preferably at most 3.0 nm, particularly preferably at most 2.0 nm,
in view of improvement of recording density and durability.
[0116] The ether composition of the present invention can be
applied to surfaces other than those of magnetic disk substrates.
For example, it is useful as a surface modifier to be applied to
the surfaces of polymer substrates for control of the refractive
indices of the substrates, as a surface modifier for improvement in
the chemical resistance of polymer substrates by surface
modification, as an additive to be added to a wire coating
material, an ink repellent (for example, for coating or for a
printer such as an ink jet printer), an adhesive for semiconductor
devices (such as an adhesive for lead on chip tape, a protective
coating for semiconductor (such as a moistureproof coating agent or
an ascent inhibitor for soldering) or a thin membrane (such as a
pellicle membrane) to be used in optical field, a lubricant for an
antireflection film for displays and an antireflection film for
resists.
[0117] A coating formed from the ether composition of the present
invention is transparent, has a low refractive index, and is
excellent in heat resistance and chemical resistance. Further, the
coating has high lubricity and has self-replenishing property.
[0118] The ether composition of the present invention is also
useful as a surfactant. For example, it may be used as an additive
to lower the surface tension of paint, a leveling agent for paint
or a leveling agent for a polishing liquid. When it is added to
paint, it is preferably added in an amount of from 0.01 to 5 mass %
in relation to the paint.
EXAMPLES
[0119] Now, the present invention will be described in further
detail with reference to Examples. However, it should be understood
that the present invention is by no means thereby restricted.
In the following:
[0120] tetramethylsilane is abbreviated as TMS,
[0121] CCl.sub.2FCClF.sub.2 is abbreviated as R-113,
[0122] dichloropentafluoropropane is abbreviated as R-225,
[0123] CClF.sub.2CClFCF.sub.2OCF.sub.2CClF.sub.2 is abbreviated as
CFE-419,
[0124] hexafluoroisopropyl alcohol is abbreviated as HFIP, and
[0125] Isopropyl alcohol is abbreviated as IPA.
(NMR Analysis)
[0126] TMS was used as a standard substance for .sup.1H-NMR (300.4
MHz), and CFCl.sub.3 was used as a standard substance for
.sup.19F-NMR (282.7 MHz). R-113 was used as a solvent for NMR,
unless otherwise specified.
(HPLC Analysis)
[0127] The ratios of the compounds in the composition were
determined with a HPLC analyzer (Prominence, manufactured by
Shimadzu Corporation) under the following conditions. Specifically,
in each run, the HPFIP concentration in the mobile phase was
gradually increased from 0% to 100%, and the mass ratios of
compounds in the composition eluted in descending order of the
number of OH groups were determined.
[0128] Analytical column: normal phase silica gel column (SIL-gel,
manufactured by YMC Co., Ltd.)
[0129] Mobile phase: R-225 (ASAHIKLIN AK-225G, manufactured by
Asahi Glass Company, Limited) and HFIP
[0130] Mobile phase flow rate: 1.0 mL/min
[0131] Column temperature: 37.degree. C.
[0132] Detector: evaporative light scattering detector
(GPC Analysis)
[0133] Mn and Mw were measured by GPC in accordance with
JP-A-2001-208736 under the following conditions, and Mw/Mn was
determined.
[0134] Mobile phase: solvent mixture of R-225 (ASAHIKLIN AK-225SEC
Grade 1, manufactured by Asahi Glass Company, Limited) and HFIP
(R-255/HFIP=99/1 in volume ratio)
[0135] Analytical column: serially connected two PLgel MIXED-E
columns (manufactured by Polymer Laboratories)
[0136] Molecular weight standard samples: four perfluoropolyethers
having Mw/Mn less than 1.1 and molecular weights of from 2,000 to
10,000 and one perfluoropolyether having Mw/Mn of at least 1.1 and
a molecular weight of 1,300
[0137] Mobile phase flow rate: 1.0 mL/min
[0138] Column temperature: 37.degree. C.
[0139] Detector: evaporative light scattering detector
(Contact Angle)
[0140] Contact angles on lubricant coatings were measured with a
contact angle meter (CA-X, manufactured by Face). The contact
angles between five drops of water or hexadecane with a volume of
about 2 .mu.L and the surface of each lubricant coating were
measured and averaged.
(Friction Coefficient)
[0141] The friction coefficient on the surface of each lubricant
coating was measured with a friction meter (Tribogear, manufactured
by Heidon) using a SUS ball with a diameter of 10 mm as a contactor
under a load 2 kg load at 25 rpm.
(Transfer Test)
[0142] After the measurement of friction coefficient, the surface
of the contactor was inspected under an optical microscope for
lubricant transfer at the four contact points and rated as
.largecircle. when no lubricant transfer was observed, as .DELTA.
when lubricant transfer was observed at 1 to 3 contact points and
as x when lubricant transfer was observed at all the four contact
points.
(Metal Ion Analysis)
[0143] The metal ion content in 1.0 g of each fraction was
determined by ashing-inductively coupled plasma-mass
spectroscopy.
(Anion Analysis)
[0144] 1.0 g of each fraction or 30 g of ultrapure water was
stirred in a polytetrafluoroethylene bottle preliminarily washed
with dilute aqueous sodium hydroxide for 24 hours to prepare a
sample, and the anion content was determined by water
extraction-ion chromatography.
(Water Content)
[0145] The water content in each fraction was measured by
Karl-Fischer coulometric titration.
Example 1
[0146] Polyoxyethylene glycerol ether (Uniox G1200, manufactured by
NOF CORPORATION) was reacted with
FCOCF(CF.sub.3)OCF.sub.2CF(CF.sub.3)O(CF.sub.2).sub.3F in the same
manner as in Example 11 of Patent Document 1 to obtain a compound
(B-1), which was liquid at room temperature. NMR analysis revealed
that in the compound (B-1), the average of (k+r+p) was 20.5,
R.sup.f was
--CF(CF.sub.3)OCF.sub.2CF(CF.sub.3)OCF.sub.2CF.sub.2CF.sub.3, the
Mn was 2,600, and the Mw/Mn was 1.15.
##STR00006##
[0147] .sup.1H-NMR (solvent: CDCl.sub.3) .delta.(ppm): 3.4 to 3.8,
4.5.
[0148] .sup.19F-NMR (solvent: CDCl.sub.3) .delta.(ppm): -76.0 to
-81.0, -81.0 to -82.0, -82.0 to -82.5, -82.5 to -85.0, -128.0 to
-129.2, -131.1, -144.7.
Example 2
[0149] Liquid phase fluorination was carried out in the same manner
as in Example 2-1 in Patent Document 1 except that R-113 was
replaced with CFE-419, and the compound (D3-1) was replaced with
the compound (B-1) to obtain a composition (c-1). The composition
(c-1) contained a compound (C-1) as a main component, and in the
composition, at least 99.9 mol % of the hydrogen atoms in the
compound (B-1) had been replaced by fluorine atoms.
##STR00007##
Example 3
[0150] Liquid phase fluorination was carried out in the same manner
as in Example 2 except that the fluorine gas concentration in the
gals blown into the liquid phase was changed from 20 vol % to 10
vol % to obtain a composition (c-2).
Example 4
[0151] Liquid phase fluorination was carried out in the same manner
as in Example 2 except that the fluorine gas concentration in the
gals blown into the liquid phase was changed from 20 vol % to 50
vol % to obtain a composition (c-3).
##STR00008##
[0152] .sup.1H-NMR (solvent: CDCl.sub.3) .delta.(ppm): 5.9 to
6.4.
[0153] .sup.19F-NMR (solvent: CDCl.sub.3) .delta.(ppm): -55.8,
-77.5 to -86.0, -88.2 to -92.0, -120.0 to -139.0, -142.0 to
-146.0.
Example 5
[0154] Example 3 in Patent Document 1 was followed except that the
compound (D4-1) was replaced with the composition (c-1), with the
composition (c-2) and with the composition (c-3), to obtain a
composition (d-1), a composition (d-2) and a composition (d-3) each
containing a compound (D-1) as a main component.
##STR00009##
Example 6
[0155] Example 4-1 in Patent Document 1 was followed except that
the compound (D5-1) was replaced with the composition (d-1), with
the composition (d-2) and with the composition (d-3), to obtain a
composition (e-1), a composition (e-2) and a composition (e-3) each
containing a compound (E-1) as a main component.
##STR00010##
Example 7
[0156] Example 5 in Patent Document 1 was followed except that the
compound (D7-1) was replaced with the composition (e-1), with the
composition (e-2) and with the composition (e-3), to obtain a
composition (a-1), a composition (a-2) and a composition (a-3) each
containing a compound (A11-1) as a main component.
[0157] NMR analysis and HPLC analysis revealed that each of the
resulting compositions contained compounds having two terminal OH
groups (A21-1a) and (A21-1b) (hereinafter the compounds (A21-1a)
and (A21-1b) are collectively referred to as (A21-1)) and compounds
having one terminal OH group (A31-1a) and (A31-1b) (hereinafter the
compounds (A31-1a) and (A31-1b) are collectively referred to as
(A31-1)).
##STR00011##
[0158] The NMR spectrum patterns of the compound (a-1), the
composition (a-2) and the composition (a-3):
[0159] .sup.1H-NMR .delta.(ppm): 3.94.
[0160] .sup.19F-NMR .delta.(ppm): -54.0, -80.1, -88.2 to -90.5,
-135.0 to -139.0.
[0161] The results of NMR analysis, HPLC analysis and GPC analysis
are shown in Table 1.
[0162] The ratio of terminal OH groups to terminal CF.sub.3 groups
in the molecule were calculated from the ratio of the area of the
peak attributed to the fluorine atoms in CF.sub.3 groups around
-54.0 ppm to the area of the peak attributed to the fluorine atoms
in CF.sub.2 groups in CF.sub.2CH.sub.2OH groups around -80.1
ppm.
TABLE-US-00001 TABLE 1 NMR analysis Fluorine gas Ratio of terminal
HPLC analysis GPC concentration functional groups [%] Compositional
ratio [%] analysis Composition [%] CF.sub.3OCF.sub.2--
--CF.sub.2CH.sub.2OH A31-1 A21-1 A11-1 Mn Mw/Mn a-1 20 7 93 1 18 81
2,000 1.07 a-2 10 3 97 1 9 90 2,100 1.05 a-3 50 21 79 20 30 50
1,850 1.13
Example 8
[0163] The composition (a-3) was purified by column chromatography
as follows.
[0164] A slurry of a particulate silica gel (MS-Gel D75-120A,
manufactured by S. I. Tech Co., Ltd.) in R-225 was packed into a
column with a diameter of 150 mm and a length of 500 mm to form a
silica gel bed with a height of 100 mm.
[0165] 150 g of the composition (a-3) was loaded on the silica gel
bed and fractionated by using extraction solvents (solvent mixtures
of R225 and IPA) with gradually increasing IPA concentrations to
obtain fractions (p1-1) to (p1-5). The volumes of the extraction
solvents, the IPA concentrations in the extraction solvents and the
masses of the fractions are shown in Table 2.
TABLE-US-00002 TABLE 2 IPA concentration Volume of extraction
solvent Fraction [%] [L] Mass [g] p1-1 0 5 50 p1-2 20 3 35 p1-3 50
3 32 p1-4 70 3 15 p1-5 100 5 3 Total: 135 Loaded amount: 150
[0166] Each fraction was analyzed by HPLC and GPC. The results are
shown in Table 3.
TABLE-US-00003 TABLE 3 HPLC analysis GPC compositional ratio [%]
analysis A31-1 A21-1 A11-1 Mn Mw/Mn a-3 20 30 50 1,850 1.15 p1-1 37
48 15 1,750 1.15 p1-2 20 39 41 1,810 1.13 p1-3 1 23 76 1,850 1.14
p1-4 0 10 90 1,860 1.10 p1-5 0 6 94 2,100 1.10
[0167] In the extraction by column chromatography, because of the
influence of the number of terminal hydroxyl groups, the
proportions of the compound (A21-1) and the compound (A31-1) were
high in less polar fractions, and the proportion of the compound
(A11-1) was high in more polar fractions.
Example 9
[0168] The fraction (p1-3) was purified by supercritical extraction
as follows.
[0169] A thick-walled stainless steel vessel (inner diameter
.phi.33 mm.times.depth 45 mm) having an inlet and an outlet, a
supercritical carbon dioxide delivery pump (SCF-210, manufactured
by JASCO Corporation), an automatic back pressure regulator
(880-01, manufactured by JASCO Corporation) and an ordinary
chromatographic column oven were assembled into an apparatus.
[0170] 30 g of the fraction (p1-3) was injected into the vessel,
and supercritical carbon dioxide was feed at a flow rate of 2.5
cc/min in terms of liquid carbon dioxide. The pressure in the
vessel was changed with time, while the temperature in the vessel
was maintained at 60.degree. C., and extracts at different
pressures were collected as fractions (p2-1) to (p2-7). The
pressure in the vessel, the pressure holding time and the amounts
of the fractions are shown in Table 4.
TABLE-US-00004 TABLE 4 Fraction Pressure [MPa] Holding time [min]
Mass [g] p2-1 10 .fwdarw. 11 75 .fwdarw. 120 0.25 p2-2 12 120 1.81
p2-3 13 120 5.46 p2-4 13.5 120 8.26 p2-5 14 120 9.17 p2-6 15 120
3.63 p2-7 16 .fwdarw. 20 .fwdarw. 25 90 .fwdarw. 60 .fwdarw. 60
0.60 Residue 0.01 Extracts + residue: 29.19 Injected amount: 30
[0171] Each fraction was analyzed by HPLC, NMR and GPC. The results
are shown in Table 5. In the supercritical extraction, because of
the influence of molecular weight, molecules were extracted in the
ascending order of molecular weight.
TABLE-US-00005 TABLE 5 HPLC analysis GPC compositional ratio [%]
analysis A31-1 A21-1 A11-1 Mn Mw/Mn p1-3 1 23 76 1,850 1.15 p2-1 37
53 9 1,750 1.1 p2-2 20 53 27 1,980 1.08 p2-3 6 42 51 2,030 1.09
p2-4 1.3 30 68 2,150 1.10 p2-5 0 4 96 2,500 1.14 p2-6 0 2 98 2,700
1.79 p2-7 0 0 100 -- --
[0172] Each fraction was examined on the solubility in R-225,
Vertrel XF (manufactured by Du Pont) and AE-3000 (manufactured by
Asahi Glass Company, Limited). Each fraction was mixed with the
solvents at a concentration of 1 mass %, and the solubilities were
examined visually. All the fractions were soluble in all the
solvents.
Examples 10 to 12
Working Examples
[0173] A carbon protective layer was formed on glass blanks for
magnetic disks (2.5'' blanks, manufactured by Asahi Glass Company,
Limited) by depositing DLC (diamond-like carbon) by radio-frequency
magnetron sputtering using a carbon target to obtain stimulant
disks. The Ar gas pressure was 0.003 Torr, and the input power
density on the target was 3 W/cm.sup.2. The carbon protective
layers were 30 nm thick. The water contact angle on the carbon
protective layers was 40.degree..
[0174] The fractions (p2-2), (p2-3) and (p2-5) were diluted with
Vertrel XF to obtain solvent compositions having a fraction
concentration of 0.01 mass %.
[0175] The stimulant disks were dipped in the solvent compositions
for 30 seconds and pulled out at a constant rate of 6 mm/sec. The
stimulant disks coated with the solvent compositions were subjected
to heat treatment in a thermostatic oven at 100.degree. C. for 1
hour to form lubricant coatings. The disks having lubricant
coatings were rinsed with Vertrel XF for 30 seconds by dipping. The
thicknesses of the lubricant coatings were measured with an
ellipsometer before and after rinsing to determine the bonding
ratios. The contact angles and friction coefficients on the
surfaces of the lubricant coatings were measured. After measurement
of friction coefficients, the surface of the contactor was
inspected under an optical microscope for lubricant transfer. The
results are shown in Table 6.
Example 13
Reference Example
[0176] A lubricant coating was formed on the surface of a stimulant
disk in the same manner as in Example 1 except that the fraction
(p2-2) was replaced with the compound (F) (FOMBLIN Z-TetraOL, Mn:
3,000, Mw/Mn=1.23, manufactured by Solvay) and evaluated in the
same manner as in Example 10. The CF.sub.3 ratio in the compound is
0.
HOCH.sub.2CH(OH)CH.sub.2OCH.sub.2CF.sub.2O(CF.sub.2O).sub.i(CF.sub.2CF.s-
ub.2O).sub.ii--CF.sub.2CH.sub.2OCH.sub.2CH(OH)CH.sub.2OH (F)
wherein i/ii=1.0.
Examples 14 and 15
[0177] Lubricant coatings were formed on stimulant disks in the
same manner as in Example 10 except that the fraction (p2-2) was
replaced with the fraction (p2-6) or (p2-7) and evaluated in the
same manner as in Example 10. The results are shown in Table 6.
TABLE-US-00006 TABLE 6 Coating Bonding Friction CF.sub.3 Contact
angle [.degree.] thickness ratio coefficient Transfer Ex. ratio
Water Hexadecane [mm] [%] [--] test 10 p2-2 0.31 108 76 1.5 60 1.2
.largecircle. 11 p2-3 0.18 102 72 1.8 75 1.2 .largecircle. 12 p2-5
0.013 88 61 2.1 82 1.4 .largecircle. 13 FOMBLIN Z 0 93 62 1.6 80
3.2 .largecircle. TetraOL 14 p2-6 0.007 n.d. n.d. n.d. n.d. n.d.
.largecircle. 15 p2-7 0 n.d. n.d. n.d. n.d. n.d. X
[0178] The results of Examples 10 to 12 indicate that a composition
comprising PFPEs having three terminal groups having specific
structures at the molecular terminals can provide a surface with a
high bonding ratio, a large contact angle and a small friction
coefficient, when the OH/CH.sub.3 ratio is more than 2 and at most
100.
Example 16
[0179] Metal ion and anion analyses of the fractions (p2-2), (p2-3)
and (p2-5) and measurement of their water contents were carried
out. The results are shown in Table 7.
TABLE-US-00007 TABLE 7 p2-2 p2-3 p2-5 Metal ions Al 10 <1 30
[ppb] Na 260 130 200 K 60 11 35 Mg 70 300 400 Ca 350 800 200 Cr 3
n.d. 1 Mn n.d. n.d. 3 Fe 10 8 20 Co n.d. n.d. n.d. Ni 5 3 10 Cu 3
n.d. 3 Zn 10 8 10 Ba 2 n.d. 3 Pb n.d. n.d. n.d. Anions F 650 1,600
1,800 [ppb] Formic acid n.d. n.d. n.d. Cl 620 230 110 NO.sub.3 n.d.
120 230 SO.sub.4 930 360 550 Oxalic acid 900 700 1,100 Water 960
940 900 content [ppm] n.d. not detected
INDUSTRIAL APPLICABILITY
[0180] The ether composition of the present invention shows a high
bonding ratio, forms a coating having a low friction coefficient
surface and is useful as a lubricant to be applied on the surface
of magnetic recording media.
[0181] The entire disclosures of Japanese Patent Application No.
2007-327619 filed on Dec. 19, 2007 and Japanese Patent Application
No. 2008-196370 filed on Jul. 30, 2008 including specifications,
claims and summaries are incorporated herein by reference in their
entireties.
* * * * *