JP2000204254A - Silsesquioxane electrolyte composition and electrophotographic charge generation element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a composition which gives a solid electrolyte layer excellent in corona protection and abrasion resistance by incorporating a silsesquioxane salt complex of which specified proportion of the total silyl units are derived from a silane having a specified number of hydrolyzable groups into a solvent. SOLUTION: This composition comprises a solvent and a silsesquoxane salt complex contained therein and contains at least one silsesquioxane of which 1-50 mol% of the total silyl (-OSi-) units present are derived from a silane having only two hydrolyzable groups. Preferably, a silsesquioxane of formula I and a mixture of polymers of formulas III and II are contained. In the formulas, -A- is a group of formula IV; -B- is a group of formula V; (j) is 0-0.5; (m) is 50-99 mol%; (n) is 1-50 mol%; m' and n' are each 10 or higher; x+y, x'+y', and x"+y" are each 1, provided (x+x'+x")/(x+y+x'+y'+x"+y")<=0.45; LINK is alkylene or the like; ACTIVE is a monovalent organic group; and INACTIVE is a mono- or divalent group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an electrolyte composition containing a modified silsesquioxane (siloxane polymer), and to an electrophotographic charge generating element containing the composition in a solid electrolyte layer. The invention is particularly useful in the field of electrophotography.

[0002]

BACKGROUND OF THE INVENTION Charge transport elements generally include a support and a charge transport layer across which charges move under certain conditions. The charge transport element includes an electrophotographic charge generating element.

In the use of such a charge generating element (also known as an electrophotographic element), incident light causes a separate charge across the various layers of the element. The electrons and holes of the electron-vacancy pair created in the charge generating layer separate and move in opposite directions to create a charge between the conductive layer and the opposite surface of the element. The charging forms a figure of electrostatic potential (also called an electrostatic latent image). The electrostatic latent image is formed by various means, for example, by image-wise radiation-induced discharge of a uniform potential preformed on the surface. Typically, the electrostatic latent image is then developed into a toner image by contacting the electrostatic latent image with an electronic image developer, and the toner image is then fused to an image receiving material. If desired, the electrostatic latent image can be transferred to another surface before development, or the toner image can be transferred before fusing.

[0004] The resistivity of an overcoat has a significant consequence in electrophotographic systems. If the protective coating has a high resistivity, the time constant for the voltage drop will be excessively long compared to the processing time of the electrophotographic element, and the protective coating will have a time constant even after photodischarge of the underlying photoreceptor. Residual potential remains. The magnitude of the residual potential depends on the initial potential, the dielectric constant of the various layers and the thickness of each layer.

[0005] Silsesquioxanes are sometimes represented by the formula (RSiO
_1.5 ) A siloxane polymer represented by _z , usually produced by hydrolysis and condensation of trialkoxysilane. Some of the polymers have been modified to include polyethers or polydialkoxysilanes. Generally, coatings of such materials are 0.5 to 10 μm thick and are applied with a hydroalcoholic solvent system. They have been in use for many years with many suppliers (eg, Dow Corning,
General Electric and Optical
(Technologies). A number of patents describe the use of such polymers to provide abrasion resistant coatings for various purposes (eg, US Pat. Nos. 4,027,073, 4,159,459). No. 206, No. 4,277,287, No. 4,324,712, No. 4,407,920,
Nos. 4,439,509, 4,595,602 and 4,923,775). Typical uses for such polymers include scratch resistant coatings on acrylic lenses, photoreceptors and transparent glazing materials, and also include use as protective coatings on photoconductor elements. For example,
U.S. Pat. No. 4,159,206 describes a neutrally charged durable coating composition comprising colloidal silica and a mixture of dialkyldialkoxysilane and alkyltrialkoxysilane in a methanol / water solvent system. Have been. It is believed that the mixture of silanes reacts to form silsesquioxane.

The surface conductivity of the polymer, the inorganic solid ion and the conductor is in the range of 1 × 10 ⁻⁸ to 10 (Ω / □) ⁻¹ [the surface conductivity is equal to the conductivity divided by the thickness (Ω). / □)
^-1 ]. The surface resistivity is equal to the resistivity divided by the thickness and expressed in Ω / □. For example, a layer having a thickness of 5 μm has a resistivity of 1 × 10 ¹⁴ Ω / −cm and a surface resistivity of 2 × 10 Ω / −cm.
It is equal to 10 ¹⁷ . Solid electrolytes are used in rechargeable lithium batteries, electrochemical sensors and displays.

More recently, US Pat. No. 5,693,44
No. 2 and 5,731,117 describe the use of silsesquioxane as a glassy solid electrolyte used as a protective coating for electrophotographic charge generating elements. Propyltrimethoxysilane is derived from such polymers to impart more organic properties to the layer, and glycidoxyether-substituted silanes form a complex with lithium iodide to provide added conductivity.
duty).

[0008] When the electrophotographic charge generating elements are to be imaged, they are typically located near corona conductors that generate various gases during use. If not properly protected, these released gases can have a deleterious effect on the photoconductor layer of the element. The glassy solid electrolyte layer of the mentioned patent offers an advance in the art as a protective coating that imparts the desired abrasion resistance and surface resistivity, but there is a need to increase resistance to damage from corona discharge Was found.

[0009]

In general, the spread of a latent image is not detected after a lapse of time in an unprotected photoconductor, but when a charge protective film is added,
Especially when the humidity is high, the image collapses with time. However, as noted above, a protective coating layer is necessary for other reasons (eg, wear resistance and other mechanical properties). The industry thus reduces the spread of latent images in such elements without sacrificing wear resistance, surface resistivity and protection from corona discharge (particularly when used at high humidity). Needs exist.

[0010]

The problems are, in order ,: (a) a conductive layer, (b) a photoconductor charge generation layer, and (c) a conductive layer.
A solid electrolyte layer comprising a silsesquioxane salt complex comprising one or more silsesquioxanes, wherein 1 to 50 of the total silyl (-OSi-) units present therein.
The problem was overcome by an electrophotographic charge generating element comprising a solid electrolyte layer in which mole percent was derived from a silane having only two hydrolyzable (HYDROLYZABLE) groups.

The present invention also provides a developed electrophotographic element comprising the above electrophotographic charge generating element and a deposited image of an electrophotographic toner.

The present invention also provides an electrolyte coating composition comprising a silsesquioxane salt complex in a solvent, wherein the composition comprises one or more silsesquioxane, wherein the composition comprises one or more silsesquioxane salts. Of all silyl (-OSi-) units
Provided is a coating composition wherein ５０50 mol% is derived from a silane having only two hydrolyzable groups.

The present inventors have found that the electrolyte coating compositions of the present invention provide greater resistance to the spread of latent images due to corona discharge when applied as a solid layer. This advantage is particularly pronounced after multiple uses. Thus, according to the present invention, the discriminability of the images is maintained even after various images are formed. In addition, the solid electrolyte layer also provides excellent wear resistance, low brittleness and desirable charge transport properties.

These advantages are achieved by incorporating specific disubstituted siloxane moieties into the silsesquioxane polymer, ie, only 50 mol% or less of the total silyl units in the polymer or polymer mixture have only two hydrolysates. This was achieved by using a specific mixture of silsesquioxane polymers, such as those derived from silanes having a functional group (as defined below). It was surprising that these siloxane moieties did not migrate to the surface of the solid electrolyte layer.

In addition, the electrolyte compositions of the present invention can be conveniently applied from aqueous alcohol solvent mixtures that do not harm the underlying layers or the environment.

[0016]

DETAILED DESCRIPTION OF THE INVENTION The present invention is based on the novel use of a specially modified silsesquioxane polymer or polymer mixture in a protective coating or solid electrolyte layer in an electrophotographic charge generating element. Since silsesquioxane exists in the form of a complex salt, the layer also carries charges.

The charge generation element of the present invention includes a conductive layer, a charge generation layer, and a solid electrolyte layer as a charge transport layer. The element can further include a separate support, which can also be a conductive layer. The solid electrolyte layers described herein can be formulated from the compositions of the present invention and can be used in a wide variety of devices (eg, photovoltaic elements, displays, and sensors). They are suitably used for charge generating elements arranged as electrophotographic elements. These elements can be positively or negatively charged, and as discussed in more detail below,
Can have a wide variety of forms.

In the charge generation element of the present invention, the charge generation layer overlies the conductive layer. The solid electrolyte layer covers the charge generation layer. The resulting element is described herein as if the element were in the form of a horizontally arranged flat plate. However, it is to be understood that the elements are not limited to any particular form, and that directional terms indicate only relative positions and not absolute directions with respect to the surroundings. is there. The solid electrolyte layer is also referred to here for convenience.
Shown as a protective coating for the charge generation layer. The term should not be understood as limiting the area of the charge generating layer, and although this is highly preferred, it does not necessarily mean that the protective coating is on top.

Generally, the solid electrolyte layer has at least 0.5
μm, preferably at least 1 μm, and generally 10 μm.
It has a thickness of up to μm. Other layers of the element can have a thickness that would be conventional in the art.

The solid electrolyte layer is composed of a silsesquioxane and a band.
Comprising complexes with electric carriers, both of which are
It is defined in more detail below. The prefix "sesqui" is 1
And １ ／ of oxygen in chemistry.
Represents a substance. Silsesquioxane therefore has the general structure
The formula (RSiO_1.5)_zWhere R is an organic group
And z represents the number of repeating units. This expression is
Therefore, ｛Si (O _1/2)_ThreeR｝_zAlso written, Silse
A useful abbreviation for squioxane, but fully cured
Except for silsesquioxane,
Not fully characterized. Silsesquioxane is not
This is important because it can be used in a fully cured state.
is there. For further predicates see US Pat. No. 5,731,
No. 117 and Glaser et a.
l. ). Non-Crystalline S
Olids, 113 (1989) 7387
I have. The term includes 1, 2, 3, or 4 respectively
Source in various silyl units bound to a single atom
The acronyms "M", "D", "T" and
"Q" is used.

As used herein, “silsesquioxane” refers to any of the conventional polymers described in the art, as well as “modified silsesquioxane” produced by copolymerization of various siloxanes. Also refers to. Examples of conventional silsesquioxanes are shown in Structural Formula II below, and examples of modified silsesquioxanes are in Structural Formulas I and
Indicated by IV.

While the silsesquioxanes used in the present invention can be present and used at various stages of curing, they can be distinguished by their state of cure. The state of cure is usually indicated by the number of hydrolysable groups reacted in the polymer matrix. In a preferred embodiment, a partially cured polymer is used because the underlying layer is heat sensitive. For example, in the following structural formula I, "m"
The silyl units (or m 'units) present in mole% are T ⁰ , T ¹ , T ¹ , as defined in the publication by Glaser et al.
It can have the state of cure which is identified as ² and T ^3. Fully cured silsesquioxane is T ^3. The partially cured polymer, substantially all of the silyl units are T ² or T ^3. Thus, the degree of cure is T ³ relative to T ³ .
It can be quantified by the ratio of ² , which ratio decreases with increasing cure.

Furthermore, the silyl units present in "n" mol% in structural formulas I and IV can be D ¹ or D ² depending on their curing state, as described by Glazer et al.
Can be expressed as Similarly, shows the state of the ratio of D ¹ is cured for D ^2, it becomes smaller as the promotion of curing. "D" silyl units will be present in the solid electrolyte layer if not covalently linked to silsesquioxane.

Generally, the carbon to silicon mole ratio in the silsesquioxane useful in the practice of the present invention is at least 1.1: 1. Preferably, the molar ratio is at least 1.2: 1.

In some embodiments of the present invention, silsesquioxanes useful in the present invention generally have the structural formula I:

[0026]

Embedded image (Wherein -A- is a structural formula Ia:

[0027]

Embedded image And -B- has the structural formula Ib:

[0028]

Embedded image ).

Further, the electrolyte composition of the present invention has a structural formula II
And III:

[0030]

Embedded image And mixtures of homopolymers or copolymers represented by

The components of these structural formulas are defined in more detail below. Particularly useful silsesquioxanes are 2
The following structural formula IV shows that two types of silyl units are copolymerized:

[0032]

Embedded image Can be indicated by:

In the above structural formula, HYDROLYZ
ABLE refers to hydroxy or monovalent, "hydrolysable groups" that readily hydrolyze under the conditions employed during polymer formation. HYDROLYZAB in polymer
LE groups represent individual groups that have not been hydrolyzed during formation due to steric constraints or other reasons. Usually, in the polymers useful in the present invention, the HYDROLYZABLE group is mostly a hydroxy group. However, other HYDROLYZABLE groups include, but are not limited to, hydrogen, halo groups (eg, iodide,
Bromide and chloride), alkoxy groups having 1 to 6 carbon atoms, aryloxy groups (where the aryl moiety can be substituted or unsubstituted (eg, aminophenyl)), substituted or unsubstituted having 7 or less carbon atoms. Alkylcarboxy groups (e.g., acetoxy and ethylcarboxy) and-(O-alkylene) _p- O-alkyl groups wherein the "alkylene" moiety is a substituted or unsubstituted alkylene group having 2 to 6 carbons , P is an integer from 1 to 3 and the “alkyl” moiety is a substituted or unsubstituted alkyl group having 1 to 6 carbons).
Other useful HYDROLYZABLE groups include 1-
Primary and secondary amino groups having 6 carbon atoms, for example-
N (alkyl) _2, where each alkyl group can independently have from 1 to 6 carbon atoms, and -NH
(Alkyl) wherein the alkyl group has 1 to 6 carbon atoms, and an alkylcarboxy group (or carboxylalkyl group) wherein the "alkyl" moiety is 1 to 6
(For example, acetoxymethyl and acetoxyethyl)]. Virtually all HYDR
Preferably, the OLYZABLE group is a hydroxy group.

A small percentage of silicon atoms can carry two or three "non-hydrolyzable" organic groups, or a small percentage of silicon atoms can be replaced by another metal atom, for example, aluminum; Alternatively, a small percentage of the silicon atoms may have a LIN as described herein.
It could also carry organic groups that are not within the definition of K-ACTIVE and INACTIVE.

The silsesquioxanes and other polymers useful in the present invention are relatively large oligomers or polymers. The total number of silyl units represented by both “m” and “n” in structural formulas I and IV (ie, the total number of silyl units) should be at least 10 for each polymer. As the number of silyl units increases, silsesquioxane actually becomes a very large single molecule. As in highly crosslinked polymers, there is in theory no upper limit on the number of silyl units, and the total number of silyl units can be very large. Preferably, the silsesquioxane polymer has at least 25 total silyl units, divided into molar ratios defined by m and n. Given that the relative weight percentages of the silsesquioxane and the polymer structures of structural formulas II and III are adjusted as follows, m 'and n' are likewise at least 10, preferably at least 20 respectively. It is.

In Formula IV, R ′ and R ″ are independently substituted or unsubstituted alkyl groups having 1 to 10 carbon atoms (eg, methyl, ethyl, propyl, isopropyl, t-butyl, chloromethyl , Hexyl, benzyl and octyl), or substituted or unsubstituted aryl groups having 6 to 10 carbon atoms in the carbocycle (e.g. phenyl, m- or p-ethylphenyl, m- or p
-Methylphenyl and naphthyl). in this way,
The R ′ and R ″ groups can be the same or different groups. However, preferably, R ′ and R ″ are each methyl, ethyl or phenyl. Most preferably, each is methyl.

Since R ′ and R ″ are both non-hydrolyzable groups (as “hydrolysable” is defined above), there are only two silyl units containing R ′ and R ″. Derived from silanes with only HYDROLYZABLE groups. One or more such silanes can be used to produce silsesquioxanes useful in the practice of the present invention.

In structural formulas I and IV, n is silyl (-
At least 1 mol%, preferably at least 10 mol%, and up to 50 mol%, based on the sum of OSi-),
It is essential that the content is preferably 25 mol% or less. Correspondingly, m is 50-99 mol%, preferably 75
~ 99 mol%. Thus, those skilled in the art will readily be able to adjust m and n to provide the desired properties from the various types of silyl units.

For a mixture of polymers represented by structural formulas II and III, the mixture of polymers is HY
The weight of each individual polymer such that it contains only 1 to 50 mol% (based on the total number of silyl units in the total polymer of the mixture) of silyl units derived from silanes having only two DROLYZABLE groups. It is desirable that the percentage be adjusted.

The value of j in the above structure is less than or equal to 0.5 and greater than or equal to 0. Preferably, j is greater than or equal to 0 and less than or equal to 0.4. More preferably, it is between 0.1 and 0.4. Atay of j corresponds to the molar percentage about the total of T ² + T ³ silicon atoms of T ² silicon atoms. When j is 0 to 0.5, this is reflected in T ³ / T ² of 1: 1 to 0: 1. The preferred ratio is between 0.7: 1 and 0: 1.

In the above structure, the sum x + y, x '+
y ′ and x ″ + y ″ are independently substantially equal to one. x
And y (and similarly, x ′ and y ′, and x ″ and y ″), ie, the “active” units (LINK-AC
The relative molarity of the silyl groups carrying the TIVE groups) and the "inactive" units (silyl groups carrying the INACTIVE groups) can be varied to provide the desired resistivity. In a preferred embodiment of the invention, the "active" group is the 4 of the polymer's silyl group.
Less than 5 mol%. In other words, (x +
x ′ + x ″) / (x + y + x ′ + y ′ + x ″ + y ″) is less than or equal to 0.45. In Structural Formula IV, x / (x + y) is less than or equal to 0.45.

INACTIVE represents an aromatic or non-aromatic group having 1 to 12 carbon atoms. INACTIVE is a group that cannot participate in the siloxane condensation reaction and carries no charge. The following monovalent or divalent organic groups are examples of suitable INACTIVE groups: substituted or unsubstituted alkyl groups having 1 to 12 carbons (linear or branched alkyl groups including benzyl groups) ), A substituted or unsubstituted fluoroalkyl group having 1 to 12 carbons (including a linear or branched alkyl group) and a substituted or unsubstituted cycloalkyl group containing a 5- or 6-membered carbon ring ( For example, a substituted or unsubstituted cyclopentyl and cyclohexyl group) and a substituted or unsubstituted aryl group containing a 6- to 10-membered carbon ring (eg, a substituted or unsubstituted phenyl and naphthyl group). The monovalent group is attached to the Si atom of a single silyl unit of the silsesquioxane. The divalent group is bonded to the Si atoms of the two silyl units. The INACTIVE groups can be all the same or different throughout the polymer.
Specific examples of monovalent INACTIVE groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, n- Includes decyl, perfluorooctyl, cyclohexyl, phenyl, dimethylphenyl, benzyl, naphthyl and trimethylsiloxane groups. Representative divalent INACTIVE groups are
It is a 1,4- or 1,3-phenylene group bonded to two silyl groups of the silsesquioxane.

LINK represents a divalent radical corresponding to the monovalent radical described above for defining INACTIVE. As described above, for example, LINK is a substituted or unsubstituted alkylene group having 1 to 12 carbon atoms that can have an arylene group in the chain (eg, methylene, ethylene, methylene phenylene or isopropylene); A substituted or unsubstituted fluoroalkylene group having 1 to 12 carbon atoms which may have an arylene group (for example, fluoromethylene and other groups similar to those used in the definition of alkylene); It may be a substituted or unsubstituted cycloalkylene group containing 5 to 10 (eg, cyclohexylene) or a substituted or unsubstituted arylene group containing 6 to 10 carbon atoms in the carbocycle (eg, phenylene).

ACTIVE is a group that is present in the silsesquioxane or polymer mixture and forms a complex with the charge carrier in the solid electrolyte layer. In a preferred embodiment of the present invention, ACTIVE has 4-20 carbon atoms, nitrogen atom,
It is a monovalent organic group containing an oxygen atom or a sulfur atom (for example, in a suitable form such as linear, branched, carbocyclic or heterocyclic). Many ACTIVE groups include at least one oxy, thio, ester, imino, or amino group. Suitable ACT to form a complex with cation
IVE groups include neutral rings and chains such as ethylene oxide, propylene oxide and tetramethylene oxide, ethylene imine, alkylene sulfide, glycidoxy ether, epoxide, pyrrolidinone, amino alcohol, amine, carboxylic acid and its conjugate salts, sulfone Acids and their conjugate salts, ammonium salts, phosphonium salts, sulfonium salts and arsonium salts are included.

In at least some embodiments of the present invention, the ACTIVE group can participate as a catalyst in the siloxane condensation reaction. Examples of such groups include primary,
There are secondary, tertiary and quaternary amines. The concentration of such catalytically active silyl units can be varied to give a convenient reaction rate. In some preferred embodiments of the present invention, 0.5% of the silyl units in the polymer
３０30 mol% includes any of the following active groups:

[0046]

Embedded image In the above groups, d and e are -LINK-ACTIV
The total number of carbon atoms in E is selected to be 4 to 25.

The following groups are also specific examples of the -ACTIVE group:

[0048]

Embedded image (In the formula, e is 2 to 5 and d is 1 to 6.)

[0049]

Embedded image (In the formula, e is 2 to 5 and d is 1 to 6.)

[0050]

Embedded image (In the formula, d is 1 to 6.)

In the groups shown above, R is hydrogen, a substituted or unsubstituted alkyl group, a substituted or unsubstituted fluoroalkyl group, each having from 1 to 12 carbons (other alkyl groups as defined above). And fluoroalkyl group) and g is 1-12. R can also be a substituted or unsubstituted alkyl carboxy group having 10 or fewer carbon atoms (eg, acetoxy and ethyl carboxy). -LINK-ACTIVE has a total carbon number of 4 to
25. Some specific examples of -LINK-ACTIVE groups include, but are not limited to, aminopropyl, dimethylaminopentyl, propylethylenediamine, propylethylenetriamine, 3-glycidoxypropyl, 2- (3, 4-epoxycyclohexyl) ethyl, 3-acryloxypropyl, 3-methacryloxypropyl, 3-isocyanatopropyl, and N-
[2- (vinylbenzylamino) ethyl] -3-aminopropyl is included. It is also possible that the substituents of the ACTIVE groups react with each other to further enhance crosslinking in the polymer, for example by ring opening of the epoxide with an amine.

Consider both the "active" and "inactive" silyl groups of silsesquioxane. The polymer can include a mixture of different "active" silyl groups, a mixture of different "inactive" silyl units, or a mixture of both. -LINK-ACTIVE and -INAC
The TIVE groups should not be substantially hydrolyzed during the siloxane polycondensation reaction used to make the silsesquioxane polymer. This is because the organic substituent is lost and the resulting polymer will exhibit a very high degree of crosslinking. Besides, -LINK-ACTIVE
And the -INACTIVE group must not be so large as to cause steric hindrance. For example, -LINK-ACTIV
A suitable maximum for the number of carbon and heteroatoms in the E group is 25, and for the -INACTIVE group is 12.

The charge carrier used for the solid electrolyte layer is selected based on the selection of the ACTIVE group in the silsesquioxane. The term "charge carrier" is used herein to describe a substance that forms a mobile species or combination of species that forms a complex with an ACTIVE group to carry charge within the solid electrolyte layer. Used. The charge carrier can be a salt or a mixture of salts. The mobile species is one or both ions of a salt, or one or both ions of a mixture of different salts. The charge carrier can also be or include a substance that is not a salt as an isolated substance. An example of the latter type of charge carrier is a complex product of molecular iodine. This type of charge carrier forms a donor-acceptor or charge-transfer complex with an ACTIVE group that has substantial ionic character through the resulting release of charge.
Provide a mobile species.

A wide variety of charge carriers can be used in the practice of the present invention. Selecting an appropriate charge carrier for a particular application is a relatively simple matter of trial and error. The charge carrier must be capable of forming a complex with the ACTIVE group, such that the silsesquioxane-charge carrier complex is conductive. In a preferred embodiment of the present invention, the charge carrier is A
The silsesquioxane-charged carrier complex must be capable of forming a complex with the CTIVE group and be electrically conductive without moisture. For salts, this is generally labeled "dissolved in the matrix." A description of this "dissolving" is given in U.S. Pat. No. 5,731,117.

The formation of a complex with a particular ACTIVE group can be measured by various means. For example, Fish et al. (Makromo)
l. chem. Rapid Commun. Volume 7 (1
986), pp. 115-120] teach that when salts or other charged carriers increase in the polymer, it is possible to track the complex formation by measuring the increase in glass transition temperature (Tg). are doing. Care must be taken to account for changes in Tg due to cure during analysis.

The charge carrier and the ACTIVE group are selected to provide a particular conductivity under low ambient relative humidity (except in the case where water loses the charge carrier) and vice versa. Specific ranges are desirable for solid electrolytes used for many different purposes. For example, a solid electrolyte layer used as a protective coating in an electrophotographic element has a desired surface resistance of the solid electrolyte layer of at least 1 × 10 ¹⁰ Ω / □, more preferably at least 1 × 10 ¹⁴ Ω / □.

The charge carrier and the ACTIVE group can also be selected to impart other properties desired in certain aspects of the invention. For example, the charge carrier used in the solid electrolyte layer of the electrophotographic element can be selected to provide both a particular triboelectric charge, i.e., a polarity and an arrangement in the triboelectric series for the toner and carrier material.

As another example, a charge carrier and AC
TIVE groups can be selected to eliminate or reduce "blooming." Ammonium salts can also be used as charge carriers; however, these salts will "bloom", ie, migrate to the surface of the solid electrolyte layer and increase the degree of ammonium activity at or above that layer. Ammonium salts are commonly used to cure silsesquioxane.

The charge carrier is an inorganic or organic alkali.
It can be a salt, one or both ions being in the complex
There is mobility. Such suitable salts include, but are not limited to:
Although not specified, LiCl, CH_ThreeCOOL
i, LiNO_Three, LiNO_Two, LiBr, LiN_Three, L
iBH_Four, LiI, LiSCN, LiClO_Four, LiC
F_ThreeSO_Three, LiBF_Four, LiBPh_Four, NaBr, N
aN_Three, NaBH_Four, NaI, NaSCN, NaClO
_Four, NaCF_ThreeSO_Three, NaBF_Four, NaBPh _Four, K
SCN, KCLO_Four, KCF_ThreeSO_Three, KBF_Four, KB
Ph_Four, RbSCN, RbCLO_Four, RbCF_ThreeS
O_Three, RbBF_Four, RbBPh_Four, CsSCN, CsC
10_Four, CsCF_ThreeSO_Three, CsBF_Four, CsBPh_Four
Is included. "Ph" used here is a phenyl group
(Substituted or unsubstituted).

A suitable concentration of the charge carrier in the silsesquioxane electrolyte coating composition or the solid layer obtained therefrom is 0.1% by weight of silsesquioxane.
-10% by weight. A generally preferred charge carrier is LiI, and a generally preferred concentration is 0.5 to 2% by weight with respect to the weight of silsesquioxane.

[0061] In some embodiments of the present invention, the silsesquioxane polymers are prepared in the United States as long as their silyl units are included in the silyl units present in "m" mole percent in structural formulas I, II and IV. Patent No. 5,731,117
It is represented by the structure described in columns 12-14 of the number.

The solid electrolyte layer used in the present invention contains a wide variety of auxiliary additives such as a filler containing metal oxide particles and organic polymer beads.

In some embodiments of the present invention, the solid electrolyte layer may now include a “secondary activator” (“secondary activator”).
y active agent "). The secondary active agent is a non-silsesquioxane containing one or more ACTIVE groups as defined for the silsesquioxane polymer described above. In certain solid electrolyte layers, the ACTIVE group of the secondary activator can be the same as or different from that of the silsesquioxane polymer.
A single secondary activator or a number of secondary activators may be present in the solid electrolyte layer. The secondary activator may or may not be included in the charge carrier.
If a secondary activator is included, the additional charge carrier provided will increase conductivity by less than 5 or 10%. Secondary activators can provide additional functions, such as a plasticizing function or a lubricating function.

The solid electrolyte layer used in the present invention is produced by a method similar to the method for producing silsesquioxane described in US Pat. No. 5,731,117. The polymer is a class of inorganic / organic substances, commonly referred to as "sol-
It can be produced at moderate temperatures by a type of procedure called "gel method". In this method, an appropriate alkoxylated silicon (or other polymerizable silane that provides an appropriate silyl unit) is hydrolyzed in an appropriate solvent medium to form a “sol”. The solvent medium is then removed and condensed to form a crosslinked gel. A variety of solvents can be used.
Water, lower alcohols (eg, aqueous methanol, ethanol and isopropanol), and mixtures thereof (eg, aqueous methanol or ethanol solutions) are generally preferred. Hydroalcoholic solvent mixtures are most preferred as the solvent medium. Conveniently, the silsesquioxane is coated from an acidic alcohol, which is a silica type R
This is because Si (OH) ₃ can be stable in solution for months at ambient conditions. Then, prior to the polycondensation reaction,
A charge carrier is added at appropriate concentrations with any auxiliary additives. The concentration of the condensation is related to the amount of cure of the sample it receives, and is related to the two most important variables in the curing process, temperature and time.

In the production of the solid electrolyte layer used in the present invention, the -LINK-ACTIVE group and the INACTI
Reactive precursor silanes containing the required ratio of VE groups to the resulting silsesquioxane include, but are not limited to, methyltrimethoxysilane, methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane,
(3,3,3-trifluoropropyl) trimethoxysilane, methyltriacetoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyldimethyl Ethoxysilane, 3-
Aminopropyldiisopropylethoxysilane, 3-aminopropyltris (methoxyethoxyethoxy) silane, 3- (1-aminopropyl) -3,3-dimethyl-
1-propenyltrimethoxysilane, N- (6-aminohexyl) aminopropyltrimethoxysilane, N-2
-(Aminoethyl) -3-aminopropyltris (2-
Ethylhexoxy) silane, N-2- (aminoethyl)
-3-aminopropyltrimethoxysilane, N-2-
(Aminoethyl) -3-aminopropylmethyldimethoxysilane, (aminoethylaminomethyl) -phenethyltrimethoxysilane, 4-aminobutyltriethoxysilane, (N, N-dimethyl-3-aminopropyl) trimethoxysilane, N -Methylaminopropyl-trimethoxysilane, N-[(3-trimethoxysilyl) propyl] ethylenediamine triacetic acid trisodium salt, N-trimethoxysilylpropyl-N, N, N-trimethylammonium chloride, N-trimethoxysilyl Propyltri-N-butylammonium bromide, 2- (3,4-
Epoxycyclohexyl) ethyltrimethoxysilane,
3-isocyanatopropyltriethoxysilane, 3-isocyanatopropyldimethylchlorosilane, 5,6-epoxyhexyltriethoxysilane, (3-glycidoxypropyl) trimethoxysilane, (3-glycidoxypropyl) methyldiethoxy Silane and (3-glycidoxypropyl) methyldimethoxysilane.

Reactive silanes having only two HYDROLLYZABLE groups useful for preparing silsesquioxanes of structural formula IV include, but are not limited to, dimethyldimethoxysilane, diethyldimethoxysilane , Diisopropyldimethoxysilane, diphenyldimethoxysilane, dimethyldiethoxysilane, diethyldiethoxysilane, diphenyldiethoxysilane and 1,7-dichlorooctamethyltetrasiloxane. Dimethyldimethoxysilane is the most preferred reactant.

It may also be desirable to include a subbing or adhesive layer between the charge generating layer and the solid electrolyte layer of the element of the present invention. The undercoat layer is selected so as to provide good mechanical bonding between the charge generating layer and the solid electrolyte layer, but not to impair the properties related to charging. The dry thickness of the undercoat layer is 0.1 ~
1.0 μm, preferably less than 0.5 μm. It is important that neither the undercoat, nor the solvent from which it is applied, damage the photoconductor layer. Suitable solvents include water,
Water-miscible solvents such as lower alcohols and mixtures thereof are included. Suitable primers include polymers that dissolve in these solvents or form emulsions. Examples of suitable primers include, but are not limited to, acrylic, polyurethane, pyrrolidone, polyamide, polyester and inorganic alkoxides, including silane coupling agents. Suitable examples of certain primers include:
There is poly (methyl acrylate-co-methyl methacrylate-co-methacrylic acid) (weight ratio 70/25/5), the synthesis of which is described in U.S. Pat. No. 5,731,117 (described above). . Another example of a specific primer is poly (vinylpyrrolidone-methacrylic acid) (weight ratio 95 /
5). Still other examples of specific primers include partially hydrolyzed aminopropyltrimethoxysilane and glycidoxypropyltrimethoxysilane.

In a preferred embodiment, the subbing layer comprises a composition comprising poly (methyl acrylate-co-methyl methacrylate-co-methacrylic acid) as described above, but with a compound containing an ACTIVE group as defined herein ( (Including nonionic surfactants).

The electrophotographic element of the present invention may include, in addition to the solid electrolyte protective coating layer, both those commonly referred to as single layer or single active layer elements, and those commonly referred to as multiactive or multiple active layer element charge generating materials. It can be of various types, including.

Single active layer and multiple active layer electrophotographic element,
Their manufacture and normal use are known and are described, for example, in U.S. Pat.
Nos. 4,578,334 and 4,719,16
No. 3, No. 4, 175, 960, No. 4, 514, 4
Nos. 81 and 3,615,414.

Suitable organic solvents for forming the polymer binder solution can be selected from a wide variety of organic solvents and are also described in US Pat. No. 5,731,117.

In the CGL, ie the coating composition for the photoconductor layer, the optimum ratio of charge generating material or charge generating material to charge transport agent to binder varies widely depending on the particular material employed. be able to. Typically, useful results are obtained when the total concentration of both the charge generating material and the charge transport agent in the layer is in the range of 20-90% by weight, based on the dry weight of the layer. In a preferred embodiment of the single active layer electrophotographic element of the present invention, the coating composition comprises 10-70% by weight of a charge generating material and 10-90%.
It contains a weight percent charge transport agent.

[0073] Any charge generating material and charge transport agent can be used in the elements of the present invention. Such materials include inorganic and organic (including organic monomeric, organometallic, and organic polymer based) materials, such as, for example, zinc oxide, lead oxide, selenium, phthalocyanine, perylene, arylamine, polyarylalkane, and the like. Substances such as polycarbazole are included.

The electrophotographic element of the present invention includes various conductive layers or supports, such as paper (of greater than 20% relative humidity), aluminum-paper laminates, metal foils (eg, aluminum foil and zinc). Foil), metal plates (for example, aluminum, copper, zinc, brass and galvanized plates), metal deposition layers (for example, silver, chromium, vanadium, gold, nickel and aluminum), and semiconductor layers (for example, first iodide) Copper and indium tin oxide) may be employed. The metal or semiconductor layer can be coated on paper or a conventional photographic film substrate such as poly (ethylene terephthalate), cellulose acetate, polystyrene and the like. Conductive materials, such as chromium, nickel, can be vacuum deposited on the transparent film support as a thin enough layer to provide for the electrophotographic element to be exposed from the opposite side.

The electrophotographic element of the present invention can further comprise a variety of layers commonly known as useful in electrophotographic elements,
For example, a subbing layer, a barrier layer [eg, a charge block
king layer)] and a screening layer.

The electrophotographic charge generating element of the present invention can form an image using any suitable imaging source for producing a charged image pattern on its surface. An appropriately charged toner is then applied to provide a developed or deposited toned image on the element. Methods and materials for imaging and developing the element will be apparent to those skilled in the art from the relevant literature regarding art in the art.

[0077]

The following examples are given for illustrative purposes and do not limit the invention in any way.

Preparation of the silsesquioxane of Comparative Example 1 All drugs were used in Gelest (Tullytown, P.L.).
DMS-E12 epoxypropoxypropyl-terminated polydimethylsiloxane purchased from A) (molecular weight 900-1)
100) except Aldrich Chemical
Purchased from Company. The acid scavenger bis [N-ethyl-N- (2-hydroxyethyl) anilino] diphenylmethane was prepared in the laboratory using conventional methods. The 1 liter sol-gel formulation was prepared in a 2 liter round bottom flask as follows. Glacial acetic acid (54.0 g, 0.9 mol) was added to previously prepared and stirred DMS-E12.
(2.0 g), methyltrimethoxysilane (275.4)
g, 2.02 mol), 3-glycidoxypropyltrimethoxysilane (30.6 g, 0.130 mol) and 3-
Aminopropyltrimethoxysilane (25.0 g, 0.
139 mol) was added dropwise and the reaction mixture was stirred overnight. The acidified silane was then added to water (156 g,
8.67 mol) was added dropwise and the reaction mixture was stirred overnight. Then ethanol (5
23 g) was diluted to a solids content of about 20% by weight by dropwise addition. The clear solution was stirred for 3 weeks. Acid scavenger (4.0 g, 8.1 mmol) and lithium iodide (1.5 g, 11.2 mmol) were added, and the solution was filtered through a 0.4 μm glass filter and stored at 4 ° C.

Preparation of the silsesquioxane of Example 1: The synthesis of the silsesquioxane within the scope of the present invention is described in Comparative Example 1.
The reaction was carried out as described in Example 1, except that the reaction mixture was stirred for one week and then dimethyldimethoxysilane (20.0 g, 0.166 mol) was added to the ethanol solution. The reaction mixture was stirred for an additional two weeks before adding 2% acid scavenger and 0.75% lithium iodide, and the solution was filtered as above.

Preparation of the silsesquioxane of Example 2 The synthesis of the second silsesquioxane within the scope of the present invention is similar to that of Example 1, except that DMS-E12 is omitted from the reaction mixture. And implemented. Application of silsesquioxane on photoreceptor: Acrylic primer solution (as described in Example 1 of U.S. Pat. No. 5,731,117 (supra)) at a web speed of 6 m / m
Min. At a dryer temperature of 27 ° C. on the surface of the photoreceptor.
The thickness of this layer ranged from 0.1 to 0.5 μm, typically 0.25 μm. Each sol-gel solution containing the silsesquioxane described above was then applied on this subbing layer in a separate series at a web speed of 3 m / min, first to fifth dryers at 104.5 ° C. each, 104.5 ° C, 82
Coating was carried out at a temperature distribution of ° C, 71 ° C and 27 ° C. The resulting web was subsequently cut into sheets and cured at 82 ° C. for 24 hours. The hardening of the obtained solid electrolyte layer was performed at 59.5607 MHz using a Chemical Magnetic CMX-300 solid state NMR spectrophotometer on a sample from which the coating was scraped off with a safety razor blade. The solid device thus obtained was identified by ²⁹ Si NMR spectroscopy.

The obtained three samples of the electrophotographic charge generating element were evaluated as follows.

The enhanced corona resistance of the solid electrolyte layer is
Observed by comparing the image width of the image at 10 minutes, as shown in Table I below. The image width was determined by the ambient relative humidity (R) after the film was exposed to a negative corona for 2 minutes.
H) (46-48%) and high relative humidity (82-92%)
Was measured. In all cases, the invention (Examples 1 and 2)
The element had less image spread at both relative humidity levels than the element of the comparative example including the silsesquioxane-containing solid electrolyte layer of the comparative example.

Table I周 囲 Peripheral RH High RH Time Image width Time Image width (min) (mm) (Min) (mm) Comparative Example 1 10 3.58 10 5.12 Example 1 10 3.07 10 4.58 Example 2 10 3.34 10 3.63 ──────────────────

The electrical properties of the sol-gel and composite films were found to be equivalent to each other. The films were compared by monitoring their charge, scavenge levels. In this procedure, the strip of film was run 5,000 times in the following cycle (exercise)
d). The film was charged to an initial voltage of an initial setting of 600 V and a Wratten 92 filter (10 at 630 nm).
% Cut) to xenon flash. This value was measured after one cycle. The film was then scavenged by using a green LED from -500 V to -200 V with a frontal exposure 10 times the exposure required to discharge the film. After 5000 cycles, the relative humidity was kept at 30% and the temperature was kept at 27 ° C., but the voltage was measured immediately after charging (“V _zero ”) and immediately after scavenging “V _erase ”. The voltage after the sweep after one cycle is lower than the voltage after the sweep after 5000 cycles, and the value of the difference between the sweep voltages caused by the test operation (“ΔV _erase ”) ).

The electrical properties under high intensity flash and sweep cycles are shown in Table II below. The reported voltages for the three elements are the same. This indicates that the electrical properties of silsesquioxane are not disturbed by the introduction of dialkyl- or diaryldialkoxysiloxanesilyl units.

Table II {Sample V _zero V _erase ΔV _erase } {Comparative Example 1-575-145 0 Example 1-575-125 0 Example 2-515-140 15} ─────────────────

The brittleness was determined by the American National Standards Institute test standard (Ame
rican National Standards
Institute Test Standard) P
H1.31 Brittleness of photographic film, Method B, "Wedge brittleness test" (WEDGEBRITTLENESS TES)
Evaluation was made by testing samples of the electrophotographic elements according to T). The description of the procedure is as follows.
All samples were tested at 70 ° C., 15% RH. The size of the sample was 15 mm × 305 mm. 9 ° wedge angle
Met. The length of the wedge was 15.2 cm. The larger wedge opening was 2.5 cm. The smaller opening of the clutch was 1.5 mm. The sample was a 15 mm swing-Albert parallel blade cutter (Th
wing-Albert parallel bad
eCutter) and conditioned in the designated environment for at least 24 hours. The wedge was mounted so as to support one end of a loop-type fixing jig by a clamp mechanism, and the other end of the loop was pulled (snipped) through the wedge. The sample was placed in the shadow with the side of interest facing outward when the loop was formed.
A reference mark was placed on the sample at the opening of the wedge. This mark was used as the zero point for data collection. The sample was then pulled through the wedge in a snap motion as soon as physically possible. This operation was repeated a total of six times for each element. In order to inspect the sample, the transmitted light (pip
ed transmitted light and / or surface reflected light was required. The two approaches allow for quick observation with transmitted light, but also consider that reflected light is used to identify the sample in question. This is the case because the image band has two coatings corresponding to the test. The brittle behavior of both layers was observed by transmitted light, but the nature of the top surface could be observed in a reflective fashion, taking into account the separation of the two layers when necessary. The sample was read prior to the test by using the fiducial mark on the sample and locating the crack furthest from the fiducial mark. The furthest crack is the first crack to occur, indicating the maximum diameter of the loop. The scale on the wedge gives the loop diameter at the first break and has units of inches. The higher the number, the more brittle the specimen. Six coupons were tested, the results were averaged, and the standard deviation was determined. The table below
The number shown in III is the diameter (inches / cm) of the loop where the first crack was observed.

The brittleness and percent cure are shown in Table III. One feature that reflects differences in the mechanical properties of the evaluated solid electrolyte layers is brittleness. The silsesquioxane-containing layer used in the present invention had slightly lower brittleness, although the polymer had a slightly higher degree of cure. The lower the T ² / T ³ ratio from solid state silicon NMR, the more
This indicates that the degree of cure of the polymer is higher.

Table III {Element brittle hardening (T ² / T ³ )} {Comparative Example 1 0.38 0.36 Example 1 0.32 0.33 Example 2 0.36 0.29} ────────────────────

Continued on the front page (72) Inventor Jane Robin Cowdery-Corban United States, New York 14580, Webster, Forest Lawn Drive 558 (72) Inventor John Anthony Cinicloffy United States, New York 14617, Rochester, Eaton Road 251 (72) Inventor Linda Gooden Parton United States, New York 14580, Webster, Coventry Drive 823 (72) Inventor David Stephen Wayes United States, New York 14622, Rochester, Eastwood Terrace 67

Claims (5)

[Claims] 1. An electrolyte coating composition comprising a silsesquioxane salt complex in a solvent, wherein the composition comprises one or more silsesquioxanes and all silyls present therein. An electrolyte coating composition wherein 1 to 50 mol% of (-OSi-) units are derived from a silane having only two hydrolyzable groups. (A) Structural formula I: (Wherein -A- is a structural formula Ia: And -B- has the structural formula Ib: (B) Structural Formulas II and III: (Where 0 ≦ j ≦ 0.5, m is 50 to 99 mol%, n is 1 to 50 mol%, m ′ is at least 10, and n ′ is at least 10. The total value x + y, x ′ + y ′ And x ″ + y ″ are each independently 1, (x + x ′ + x ″) / (x + y + x ′ + y ′)
+ X "+ y") is less than or equal to 0.45, and HYDROLLYZABLE is hydroxy, hydrogen, halo,
An alkoxy group, an aryloxy group, an alkylcarboxy group, a-(O-alkylene) _P- O-alkyl group (where the alkylene part is an alkylene group and the alkyl part is an alkyl group, p is 1-3), primary Or a secondary amino group, or an alkylcarboxy group (where the alkyl moiety is an alkyl group), LINK is an alkylene group, fluoroalkylene group, cycloalkylene group or arylene group, and ACTIVE is carbon atom 4 to 20, A monovalent organic group containing a nitrogen, oxygen or sulfur atom, capable of forming a complex with a charged carrier;
VE is a monovalent or divalent group containing 1 to 12 carbon atoms, and is a group which cannot participate in siloxane condensation and has no charge.) The coating composition according to claim 1. 3. The silsesquioxane has at least 10 silyl units and has the structural formula IV: (Where 0 ≦ j ≦ 0.5, m is 50 to 99 mol%, n is 1 to 50 mol%, x + y is 1, x / (x + y) is less than or equal to 0.45, and HYDROLLYZABLE is Hydroxy, hydrogen, halo,
An alkoxy group, an aryloxy group, an alkylcarboxy group, a-(O-alkylene) _P- O-alkyl group (where the alkylene part is an alkylene group and the alkyl part is an alkyl group, p is 1-3), primary Or a secondary amino group, or an alkylcarboxy group (where the alkyl moiety is one alkyl group), R ′ and R ″ are independently an alkyl group or an aryl group, and LINK is an alkylene group, a fluoro group. ACTIVE is a monovalent organic group having 4 to 20 carbon atoms, including a nitrogen atom, an oxygen atom or a sulfur atom, which can form a complex with a charged carrier. And INACT
IVE is a monovalent or divalent group containing 1 to 12 carbon atoms, and is a group which cannot participate in siloxane condensation and has no charge.) Coating composition. 4. A solid electrolyte formed from: (a) a conductive layer, (b) a photoconductor charge generation layer, and (c) the electrolyte coating composition according to any one of claims 1 to 3. An electrophotographic charge-generating element comprising a layer. 5. A developed electrophotographic element comprising the electrophotographic charge generating element of claim 4 and a deposited image of an electrophotographic toner.