DE1797204A1 - Liquid developer for electrophotography - Google Patents

Description

Ka.bush.iki Kaisha. Eic oh.
Tokyo, yes, pa3i

liquid developer for electrophographic photography

The invention relates to a liquid developer for Elektroph.otograph.ien, which has an excellent shelf life and retains its excellent development capacity even with long-term, repeated use. With the The expression "El ektrophot ogr aphi en" should include such copies with. Visible image is meant to be created by developing latent images in the form of an on top of a suitable Electrostatic charge generated electrical charge can be obtained.

It is known - that one can use a liquid developer for El ektrophot ο gra.phi en especially of the kind in which a toner composed of pigment particles and a resin polarity regulator in a paraffinic carbon is dispersed as a carrier liquid by adding either an organic acid or a metallic soap a sufficient amount Can grant development ability because the (Donar contained in it) has a pronounced positive charge

00985171720

BATH ORIGINAL

and the developer itself has excellent durability is and is able to provide clear copies of images without there, ß its ability to develop through aggregation or sedimentation the toner particles suffer. Developers produced in this way have the disadvantage, however, that when they are repeated Use of the toner inevitably loses its charge and furthermore its for rapid development implementation required surface potential sinks. Such well-known developers cannot be identified with Recognize sufficient efficiency required by the consumer to develop latent, electrophotographic

pictures
shear / must demand.

The invention therefore aims to provide a liquid Developer for electrophotography, which no longer has the above-mentioned, inadequate properties of the known liquid developer, but has an enhanced developing ability and, above all, excellent has a long shelf life and retains sufficient development potential even after repeated use.

The invention is based on extensive and thorough studies of various combinations of an Synthetic resin polarity regulators hanging, polar residues and siQ strongly influencing, organic metal compounds

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manure rait the goal of them. find those who for the production of liquid developers with im Use of excellent judgment. In this way it turned out that one was a developer with the desired, improved properties in terms of durability and persistence of developability even after repeated use can be achieved by using a so-called 2oner, i.e. a kneading

co /
misch odei "a graft polymer of pigment particles and a Consthar with polar radicals in the form of amino, amido, cyano"or'Hydroxy, together with an organic compound of a metal in particular of the 4th or a higher group of the periodic table and, if necessary, a polarity regulator in JOria of a copolymer resin, for example of lauryl methacrylate, is dispersed as a dispersing aid in a carrier liquid in the form of a hydrogen paraffin, which gives the toner a fairly pronounced, positive charge and a surface potential of up to 60-100 mV. It also emerged that the desired result would not be achieved if, for example, the pigment particles were only mixed with the polarity regulator or the organic metal compound alone, or if the mixing was carried out in the reverse order to that given above.

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The invention accordingly orders a.us a developer for electrophqtogra, phien with dispersed in a carrier liquid, by an organic metal compound positively charged toner and is characterized by the fact that the Toiior 'a.us a kneading mixture or a graft copolymer a.us pigment particles and a polymer resin with electroneua.bgebenden, polar residues in the form of amino, amido, Cyan or hydroxy and together with an organic one Compound of a polyvalent metal of the 4 or a higher group of the periodic table in the carrier liquid is dispersed.

Regarding the metal selection is to be noted that the erfindunngeiiiäß desired success do not see about by organi ~ connection with low valent lead as representatives of the 4 × group and even not at all with such is achieved, the IJetalle the 1st to 3rd group, eg aluminum , Zinc, potassium or sodium.

The organic ones are suitable for carrying out the invention Salts of such polyvalent metals with acids such as ilaphthenic acid, stearic acid or oleic acid, as well as a.uch whose Acet3rla.cet0na.te. Give of the polyvalent metals those a better effect, which a higher Koordina.-tionosahl if they are used for the purpose of KonnxLcxsnlsbildimg

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Coupled with easier organic or inorganic compounds are. The insertion of the organic metal compounds. dmig in the liquid developer can either in the form of a so-called concentrated Eoners, "in which they are carried out with a little carrier fluid in the IQietge mentioned

co /
mix or graft polymer is mixed in, or you can add it to the already finished dispersion of the kneading * -

c o / ■ '-

mixture or graft polymer in the carrier liquid KUgc'boii. Developers provide both types of manufacture with · ■ Virtually identical, excellent properties.

Pigments which can be used are for example Puuss, anil in black 55, monolith yellow and phthalocyanine. To the suitable synthetic resins with polar radicals of the type specified include, for example, dimethylaminoethyl methaerylate, ! [, ii-jJimethylraetha.crylaiaid, acrylonitrile, hydroxyethyl methacrylate and ■ vinyli> yridine. For the purpose of increasing the dispersion "bax '^ oit Deo toners in the carrier liquid can be used Lia.tox'iaiien also, if necessary, in the form of copolymers on from hü hear alcohol esters of acrylic or methacrylic acid 'and .these monomers. In this case one kaiin the pigments in the - catfish with these synthetic resins combine that either the monomers are polymerized for themselves and the resulting copolymers with the pigment particles Kneaded or the pigment particles during the

1737204

Polymerization process is mixed with what are known as

co /

Graft polymers generated.

As a carrier liquid for the toners according to the invention Many different dispersing media are suitable, e.g. normal paraffinic, isoparaffinic or halogenated © Hydrocarbons, ligroin, uoluene, benzene, like them have been used before. You are through one

10 .high electrical resistance of at least 10 olimera and a low dielectric constant of 3 or less. Among them are the isoparaffinic Hydrocarbons a.l, -j "especially bra.uchba.r proven, as they are for example under the protected brand name Shellsol 71 from Shell Oil Company or under the trademark Isopa.r H or G from Esso Standard Oil Company can be obtained.

On the mixing ratio of the three basic components pigment parts, polarity regulator and organic metal compound komr.it it doesn't matter. This is especially true in the event that the polarity-regulating synthetic resin consists of a homopolymer of a monomer with the mentioned polar radicals. If so, instead uses a two or three component copolymer that in addition to this monomer, one or two monomers without

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contains polar residues, then the "former must be at least Υ, Ό present. For 1 part by weight of pigment part. c lien one takes the" best "0.5 Ms -10.0 at least one polarity regulator as well as 0 , 05 Ms 0.5 parts by weight oi ^ anisohe Let allvcr cohesive.

The liquid developers according to the invention are suitable not only for the development of such latent, el.ektrosta.ti ~. shear images printed on electro-motographic copier media were sucked, which a, us a carrier from p. 3. tetaiLlMech odex · sheet material made conductive on the back ■ a.us a.B. Made of paper, the front with Help an electrically insulating ha, raes with a Layer of photoconductive substances, ε, Β. Zinc or Titanium oxide, covered, but also everything else latent images including those obtained by printing an electrical charge on a recording material covered on the front side with an insulating film, as well as those generated by charge carriers with each electric charge existing LatentMldem transferred have been. ;

In the following, the invention is illustrated by means of preferred embodiments explained in more detail. . :

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009851/1720

SAD ORIGINAL

Example 1 -

A mixture of 10.0 Hol lauryl methacrylate, 1.0 IJoI Dimethylarainoäthylmetha.cryla.t and 0.06 mol azobisisobutyl-

the end/

nitrile as a Polvmerisa.tionslöser was for 10 hours at

90 ⁰ O in a stream of nitrogen to form a Iümatlia.rz acting as a polarity regulator. 1.5 parts by weight of this synthetic resin were for 20 hours in a ball mill with 1 part by weight of carbon black (Handelswaxe Mogul A from Godfrey I. Ca, bot), 0.33 parts by weight of Nickeliio.phthena.t (with 10 wt. Ίο Nickel content) and 3 parts by weight of isoparaffin hydrocarbon (previously mentioned Hanxlclawa.re. Isopar H) processed into a concentrated toner, of which 5 g were finally dispersed in 1000 ml of Isopar II, and a liquid developer according to the invention with positively charged toner to accomplish.

Y / emi men developed a negatively charged electrostatic latent image with this developer, which was obtained with the aid of the type BS-I electrostatic copier manufactured and sold by the applicant a very clear copy of the image. Diose JiervorragGiidG jlildkla.rlioit also kept up to the last sheet of 2000 prints, which one after the other with dom. made by the same developer. Even with oechomoimtigor

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The developer produced in this way lost nothing in terms of storage Eiitwicklmigsverniögeii a.

Example 2

If you repeat example 1, in which only that nickel naphthenate has been replaced by acetylacetone nickel, mail received a developer regarding durability and repeated use that of Example 1 is practical soon 'wax ..

Example 3

A mixture of 10.0 mol of octyl methacrylate, 1.0 mol of dimethylaminoethyl methacrylate, 0.06 "mol of azobisisobutylnitrile and 10.0 mol of i'oluene was copolymerized to give a polarity regulator / ichtst rush together with 0.25 weight steep fuel black (commercial product of Orient Chemical company), 1 Gewichtöteil carbon black (commercial product of the company Mitsubishi 44 laitnubishi Chemical Industries Ltd.), 0.14 G-ewichtöteilen KobaltnaphtlLcnat (with 10 G ew. - $ cobalt content) and 6.0 G c ewi ht st en eil of erv / ähnten Isopax H 25 .Stunden long konzentrierton in a ball mill to a liquid Entverarbeitet from which finally 4 Si in 1000 ml -

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BATH

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Isopa.r H dispersed, provided the ready-to-use developer according to the invention.

The investigation of this developer in the example 1 was found to provide very clear copies of the images and in terms of durability and repeatability was practically the same as that of Example 1.

Example J-,

According to the procedure of Example 1, a mixture of 10.0 mol of octadecylinetiiacrylate, 1.0 mol of ΙΤ, ΙΙ-dimethyl methacrylate, 0.03 mol of azobisisobutylnitrile and 20.0 mol of toluene was copolymerized to give a polaxicity regulator. IHA 2.0 parts by weight were added together with 1 part by weight of carbon black Mogul merchandise A, see Example 1), 0.33 part by weight of s m. Manganese and 3.0 Gevri-chtsteilen Isoparaffinlcohlenwasserstoff (merchandise Isopar H, see example 1) 25 hours long carefully in a ball mill

liquid
ia ent ri ered / developer processed, from which finally

5.5 gjin 1000 ml Isopar H dispersed, the ready-to-use, supplied a developer according to the invention.

In its evaluation according to Example 1, this developer was also shown to be the ones described in the earlier examples.

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* AO ORIGINAL

th developers regarding ICLa.r> ieit of the image copies, durability and repeated accessibility are equivalent.

Example 5

Example 1 was used.

The toner and polarity regulator were run for 15 hours,

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Graft polymerization carried out at 90 ° C. in a ball mill a mixture of 20.0 weight st part en la.urylnethacryla.t, 3.0 weight is based on dimethylaJninoethyl: ': iethacrylat ,: ό, Ο parts by weight liui? (Merchandise I-Iitsubishi 44} see Example 3), 0.07 percent by weight of azobisisobutylnitrile and 6.0 parts by weight of loluene

The concentrated, liquid developer has been used through 10 volumes Processing of 1 part by weight of this toner with 0.25 parts by weight of cobalt naphtha and 5 »0 parts by weight of isoparaffinic hydrogen (commercial product Isopax II, see example 1) in a ball tube; manufactured.

The ready-to-use developer according to the invention finally consisted of a dispersion of 6 g of this consistency α in 1000 ril Isopar II. In terms of clarity of the image copies, durability and repeated Benin, it was practically German by iieisiilcl. 1. .

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Claims (5)

Claims 1.) Developer for electrophotography with in a carrier liquid dispersed em, by an organic metal compound positively charged toner, characterized in, that-the toner a. from a kneading mixture co / or a graft polymer of pigment particles and polymer resin with electron donating, polar radicals in the form of amino, amido, cyano or hydroxy and together with an organic compound of a polyvalent metal of the 4 · or a higher group of Periodic table is dispersed in the carrier liquid. 2. Developer according to claim 1, characterized in that the polymer component of the toner is either a.us one Homopolymer of ionomer dimethylaminoethyl methacrylate, Ν, ΐί-dimethylmetha.crylamide, vinylpyridine, acrylonitrile or hydroxyethyl methacrylate or a copolymer of such a monomer with a monomeric acrylic or Methacrylic acid esters of higher alcohols consists. - 13 - 0 0 9 8 51/17 2 0 BAD OeiGJNAL . - 13 - 3. Developer according to claim T or 2, characterized in that the pigment particles consist of a.us EuB ₅ aniline black, monolith yellow or phthalocyanine. 4. Developer according to one of the preceding claims, characterized in that the organic metal compound from a metal salt of Na / phthene, stearic or Oleic acid or an Aeetyla, ceton ~ metal compound "consists. 5. Developed according to one of the preceding claims, characterized in that the carrier liquid a.us a normal paraffinic, isoparaffinic or halogenated hydrocarbon or from toluene or Benzene is composed. . 009851/1720