Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/22—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
  • C08G77/04—Polysiloxanes
  • C08G77/06—Preparatory processes
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/05—Organic bonding materials; Methods for coating a substrate with a photoconductive layer; Inert supplements for use in photoconductive layers
  • G03G5/0528—Macromolecular bonding materials
  • G03G5/0557—Macromolecular bonding materials obtained otherwise than by reactions only involving carbon-to-carbon unsatured bonds
  • G03G5/0578—Polycondensates comprising silicon atoms in the main chain
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/02—Charge-receiving layers
  • G03G5/04—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor
  • G03G5/06—Photoconductive layers; Charge-generation layers or charge-transporting layers; Additives therefor; Binders therefor characterised by the photoconductive material being organic
  • G03G5/07—Polymeric photoconductive materials
  • G03G5/078—Polymeric photoconductive materials comprising silicon atoms
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
  • G03G5/00—Recording members for original recording by exposure, e.g. to light, to heat, to electrons; Manufacture thereof; Selection of materials therefor
  • G03G5/14—Inert intermediate or cover layers for charge-receiving layers
  • G03G5/147—Cover layers
  • G03G5/14708—Cover layers comprising organic material
  • G03G5/14713—Macromolecular material
  • G03G5/14747—Macromolecular material obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • G03G5/14773—Polycondensates comprising silicon atoms in the main chain

Definitions

• ABSTRACT A process for obtaining a substantially linear homopolymer and/or copolymeric material from a cyclic trimer such as 1,3,5-trimethyl-1,3,5-tri(N-ethyl-3- carbazyl)cyclotrisiloxane alone or in combination with cyclic trimers or tetramers exemplified by the formulae and in the presence of tetramethylammonium'silanolate or corresponding alkali metal salt as initiators; the polymeric product, and photoconductive members utilizing such product demonstrate excellent structural and electronic properties for xerographic purposes.
• a cyclic trimer such as 1,3,5-trimethyl-1,3,5-tri(N-ethyl-3- carbazyl)cyclotrisiloxane alone or in combination with cyclic trimers or tetramers exemplified by the formulae and in the presence of tetramethylammonium'silanolate or corresponding alkali metal salt as initiators; the polymeric
• photoconductive layer is uniformly electrostatically charged in the absence of light or other activating radiation end, thereafter, exposed to a light'pattern which can correspond to a negative image.
• the areas ofthe photoconductive layer which are so exposed selectively lose their charge much more rapidly than non-exposed areas.
• the photoconductive layer at least temporarily retainsa charge corresponding essentially to a latent positive image.
• This image can then be conveniently developed to form a visible positive image by contacting with oppositely charged pigmented particles commonly identified as toner particles which will adhere mostly to the charged areas.
• the resulting image may optionally be permanently affixed to the photoconductor if the imaging layer is not to be reused. This usually occurs with binder-type photoconductive films where the photoconductive imaging layer is also an integral part of the finished copy.
• a latent image is developed on the imaging surface of a reusable-type photoconductor, it is transferred'to another substrate and then permanently affixed by using any one of a variety of well-known techniques such as by overcoating with a transparent film, or by'therma'l fusion of the toner particles to the sheet.
• the materials in the photoconductive layer'must be capable of rapidly changing from an insulative, to a chargeconductive, and then back to an insulative condition to permit cyclic use of the imaging surface. Failure to re vert back to the insulative state before each succeeding I charging sequence will result in a high dark decay rate commonly referred to as fatigue.
• a further object of the present invention is to discover and synthesize a new active polymeric matrix material which is compatible with high quantum efficiency photoconductor material and which retains its flexability and durability.
• R, and R are individually defined as a lower alkyl group, including alkyl groups of 1-8 carbon atoms such as methyl propyl, isopropyl and n-octyl, and preferably as an alkyl of l3 carbon atoms;
• R is a polymeric end group, including hydrogen or an acyl group such as an alkyl carbonyl having an alkyl moiety of 1-18 carbon atoms and an aryl carbonyl such a phenyl carbonyl exemplified by phenylcarbonyl, alkyl substituted phenylcarbonyl or halophenylcarbonyl; and
• m, n and 0 are positive numbers commensurate with a number average molecular weight of at least about 1,000 and conveniently varying from about 1,000 1,000,000 or higher, the numbers 3n and 30 being defined so as to fall within a ratio of about 3:1 to 1:8 in a random or block copolymer.
• the copolymers tend to exceed the homopolymers in molecular weight, a preferred although non-exclusive range being about 1,000 50,000 for the homopolymer and about 1,000 500,000 for the copolymer, depending upon the ratio of monomeric units and the definitions of R and R
• the above-defined homopolymers and copolymers are found to be multifunctional in nature (i.e..
• steps (c) and (d) prefera- 5 bly proceed as follows:
• Intermediate A preferably includes the following cyclic trimers:
• the reaction can best proceed in the presence of tetra alkylammonium silanolate at a temperature of about 80 160C. Preferably this reaction is effected under vacuum for a period of about 3-5 hours. Extended reaction periods particularly at the higher temperature range, however, favors an increased randomness of units attributed to indiscriminate cleavage of long chains by initiator groups.
• EXAMPLE Ill (p-3) 0.01 Mole of cyclic trimer of the formula EXAMPLE IV (p-4) 0.01 Mole of cyclized dimethyl siloxane tetramer of the formula Si0 L 4 and 0.04 mole of the trimer of Example 1 are dissolved in tetrahydrofurane and agitated with about 150 ppm of potassium tetramethyl silanolate at 60C for 3 hours. The temperature of the thickened reaction mixture is then raised to about 130C for three additional hours.
• the resulting polymeric product (P-4) is washed and identified as an essentially random linear copolymer which is conveniently represented by the formula li-O l R: f a I wherein the ratio of p-to-q is about 3 to l and R is lpyrenyl.
• the product is tested and results reported in Tables n-m below.
• EXAMPLE Vl (P-6) 0.003 Mole of the cyclic tetramer and 0.00] mole of the cyclic trimer of Example V are admixed with ppm of tetramethylammonium silanolate and heated at about C for 2 hours in a sealed glass ampule under vacuum.
• the resulting copolymer coded as P-b is washed with methanol and identified as linear poly( methyl-N-ethyl-3-carbazyl-siloxy )dimethylsiloxane co polymer represented by the formula wherein R is identified as the N-ethyl-3-carbazyl group, and p and q are in a ratio of about 1:4.
• the methanol-washed product is tested and evaluated in Tables ll-lIl.
• EXAMPLE Vll (P-7) 0.01 Mole of the cyclic trimer and 0.05 mole of the cyclic tetramer of Example V are dissolved in tetrahydrofuran and agitated in the presence of about 150 ppm potassium dimethyl silanolate initiator at about 120C. After 3 hours the reaction temperature is gradually raised to about 160C for 1 hour to obtain an essentially linear copolymer conveniently represented by the formula wherein R is N-ethyl-3-carbazyl group, and p and q are in a ratio of about l:6. The methanol-washed product is repeated in Table I.
• EXAMPLE IX (P-9) Example VII is repeated except that the trimcr reactant is a cyclic compound of the formula EXAMPLE X
• Six test photoreceptor strips identified as T l and as control are prepared in the usual manner by vapor condensation of selenium alloy (60 u) onto an aluminium foil substrate. A polymeric overcoat is then cast onto the resulting selenium photoconductive layer from tetrachloroethane-tetrahydrofurane solutions of products P 26 respectively. to obtain polymeric overcoats having an average thickness of about 12 u.
• the resulting test components are then corona charged. checked for charge retention and discharged by exposure for seconds with a 200 watt tungsten-iodine lamp at a distance of centimeters.
• the control test is prepared by applying onto the selenium alloy a homopolymer resin overcoat having a molecular weight of about 500,000 consisting of monomeric units of the formula The results are reported in Table III below.
• holes injected from the selenium layer into the polymeric overcoat of T 1-5 are sufficient to discharge a functionally useful amount of the surface charge.
• R and R,- are individually defined as a lower alkyl I group; R is defined as a polymeric end group; and m. n and are positive numbers commensurate with a molecular weight of at least 1,000. the respective numerical products represented by 3n and 40 having a ratio of about 3:1 to 1:8. 2.
• R; and R are polymeric end groups
• a xerographic photoreceptor component comprising a substrate and at least one photoconductive layer with an applied active matrix overcoat layer consisting essentially of a polysiloxane of the formulae m or wherein R, is defined as a lower alkyl. a lower alkoxy.
• R, and R are individually defined as a lower alkyl group
• R is an aromatic polycyclic group having at least three fused ring nuclei
• R is a heterocyclic group.
• R and R are polymeric end groups; and R is an alkyl group of 2-8 carbon atoms or an aryl group.
• R R, and R in the polysiloxane polymeric material are individually defined as an alkyl group of l3 carbon atoms; R is an aromatic polycyclic group having at least 3 'fused ring nuclei; and R and R are polymeric end groups.
• R, R and R in the polysiloxane polymeric material 16 are individually defined as an alkyl group of 13 carbon atoms; and;
• R is a heterocyclic group.
• a method for obtaining photoreceptor elements having improved electronic and mechanical properties for xerographic, copying purposes said elements having at least a charge conductive substrate and a photoconductive layer the improvement comprising applying onto the substrate at least one of 1 the photoconductive layer or (2) an overcoat layer having as a polymeric component a linearpolymer represented by the formulae R, is defined as a lower alkyl group;
• R is defined as hydroxyl, hydroxy. or other polymeric end group

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Physics & Mathematics (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• General Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Silicon Polymers (AREA)
• Photoreceptors In Electrophotography (AREA)

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Citations (4)

• 1973
  • 1973-05-07 US US357987A patent/US3899328A/en not_active Expired - Lifetime
• 1974
  • 1974-01-28 CA CA191,090A patent/CA1031895A/en not_active Expired
  • 1974-04-26 DE DE2420389A patent/DE2420389C3/de not_active Expired
  • 1974-05-02 JP JP4963474A patent/JPS5325652B2/ja not_active Expired
  • 1974-05-06 GB GB1975774A patent/GB1474195A/en not_active Expired
  • 1974-05-06 IT IT22316/74A patent/IT1010430B/it active
  • 1974-05-07 NL NL7406140.A patent/NL157033B/xx not_active IP Right Cessation
  • 1974-05-07 BR BR3708/74A patent/BR7403708D0/pt unknown
  • 1974-05-07 FR FR7415776A patent/FR2228808B1/fr not_active Expired

Patent Citations (4)

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