DE1938001A1 - Liquid developer for electrostatic photography - Google Patents

Description

PATENT LAWYERS _y - DIPL.-ING. H. LEINWEBER dipl-ing H / ZIMMERMANN

1938001 8 MUndien2, Rosonlal7, 2nd ed.

! •! .- Addr. uinpatMindira

July 25, 1969

Under ZeletiwiIw / XIU / C

-MITSUBISHI EAPER MILLS, LTD., Tokyo / Japan Liquid developer for electrostatic photography

The invention relates to a developer for developing of electrostatic images in electrostatic photography ie. This developer consists of colloidal particles, which are dispersed in an insulating liquid.

In electrostatic photography, an image is generally created by exposure to light or radioactive rays as a positively or negatively charged pattern on a thin Layer of photoconductive insulator. A charged, fine, colored powder is used to make this image visible commonly referred to as a toner or developer. In the liquid development process, a developer is used used ,, which by dispersing in the form of a colloid of, fine pigment, dye or synthetic resin in a liquid with a large resistance value of TO cm

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■■■ ".- 2 - ■ ■ .. '■" · ■

or made about it. With regard to the top t. Surface chemistry, these fine particles have an electrical effect. Charge of a certain size in relation to the liquid. Due to this electrical charge, the particles adhere to. [ 'An electrostatic image and thus cause its decision ι development. These particles are for use as a developer having suitably cheap electric charge characteristics and, after development, and at the same \ tigern drying the liquid adhere to the fotoleitenien layer. Furthermore, the colloidal dispersion system must \ s / be tabil and must not be slightly or agglomerate.

The invention provides a developer who the meets the above requirements. According to the invention was a Developer with excellent adhesiveness and dispersibility created, wherein an amino group-containing polymer: and a carboxyl group-containing copolymer .von Acryl-I or methacrylic acid and its esters were used.

A known isoparaffinic hydrocarbon is normally used as the dispersion medium in the developer of the present invention; but you can also use purified. Use homely paraffin. In the ι developer according to the invention, two synthetic resins are used, wherein: the amino group-containing polymer of alkylaminoethylmeth-; ^! acrylates, while the mixed polymer containing earboxyl groups of acrylic or methacrylic acid and an ester thereof consists of mixed polymers which contain long-chain alkyl groups and are soluble in paraffinic hydrocarbons

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are. Examples of preferred alkylaminoethy methacrylates containing Polymers are Polydialkylaminoäthylmethacrylate, mixed polymers from Dialkylaminoäthylmethacrylateri and styrene, as well Mixed polymers from DiyäLkylaminoäthylmethacrylaten, styrene and Alkyl methacrylates, examples of mixed polymers containing carboxyl groups of acrylic or methacrylic acid and esters thereof are mixed polymers, which lauryl methacrylate and methacrylic acid in a molar polymerization ratio of 99: 1 to .90: 10, copolymers containing lauryl methacrylate; and acrylic acid in a molar polymerization ratio of 99: 1 to 90: 10 contain, as well as mixed polymers which contain stearyl acrylate and acrylic acid. In addition to this, mixed polymers containing maleic acid, crotonic acid or a similar acid can be used. The alkyl groups in the above alkyl methacrylates or acrylates must be at least 6 carbon have a tome; those having 4 or less carbon atoms are not used in the invention.

The polymers which contain alkylaminoethyl methacrylate are preferably those polymers which are soft and do not dissolve in aliphatic hydrocarbon solutions. They are within certain limits in aliphatic hydrocarbon solutions. the above-mentioned copolymers of methacrylic or acrylic acid and esters thereof which contain long-term alkyl groups and carboxyl groups, soluble. This is due to the fact that the amino groups in the Alkylarainoäthylmetnacrylatpolymeren and the carboxyl groups _in: the soluble copolymers together · are attached, and make the Alkylaminoäthylmethacrylatpolymeren soluble. A solution in which the polymers are completely dissolved is transparent, apparently does not contain any colloidal particles

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ORIGINAL BATHROOM

and shows no development potential when as such

is used. However, if the amount of Alkylaminoäthyl- ^; . methacrylate polymer increased above the solubility limit.; the solution becomes cloudy. Such a liquid contains a dispersion of fine colloidal particles of.

Polyaminoäthylmethacrylatderivaten, which ein.elektische; · Have charge opposite the liquid. If, therefore, ■ a photoconductive one having an electrostatic image

■■. The layer is immersed in this liquid, the collo-

™ ι idalen particles of Pplyalkylaminoäthylraethacrylatharzes on the electrostatic image, and give an image which has a wonderful sheen in visible light.

The colloidal resin system obtained in the above manner is not sufficiently stable, but agglomerates, after standing for a long time. However, if you have fine pigment or If dye particles have previously dispersed during the formation of the colloid, the colloidal resin particles grow, whereby the pigment or dye particles serve as the core and thus form a stable dispersion system. The colloidal Particles have a favorable electrical charge and have excellent developer properties for electrostatic images. It was also found that

the above colloidal system by adding methyl glycerin or diethylene glycol dihydroabietate or a divalent one or trivalent salt of dihydroabietic acid can be further stabilized.

The above dye or pigment particles are preferably used in an amount of 0.5 to 10 g / 100 ml of the Dispersion medium added. The mixing ratio of the alkyl

.aminoethyl methacrylate-containing polymers to form copolymers from acrylic or methacrylic acid or an ester thereof is preferably 1/10 - 1: 1. Furthermore, the amount of acid should in the copolymer suitably $ 10 or less be.

The invention will now be illustrated by the following examples further explained.

Phthalocyanine blue. 0.3 g

Dimethylaminoäthylmethäerylat-Poly ~

meres - 0.5 g

Mixed polymer of methacrylic acid and lauryl methacrylate (molar ratio 6: 94). '■ ■. 0.8 g

Xylene 2 ml

A mixture of the above compounds was thoroughly incorporated into an ultrasonic dispersing device. and a Isoparaffin hydrocarbon solvents (e.g. Isopar ■ -H-, manufactured by the Esso Standard Oil Go.) is slow added until the total is 10 ml. The liquid produced in this way contains colloidal particles of the dimethylaminoethyl methacrylate resin polymer, which contain particles of phthalocyanine blue as a nucleus. The liquid Due to the dispersing effect, it forms methacrylic acid-lauryl methacrylate copolymers a stable dispersion. 1 ml of this dispersion was mixed with 100 ml of an isoparaffin carbon / hydrogen solvent (e.g. * Isopar H) .diluted, with a detecifier for electrostatic photography was obtained. In this liquid the particles point

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a positive charge. When you get the liquid to the Developing an electrostatic latent image, e.g. on the electrophotographic known as the Iiamen Elektrofax Zinc oxide paper, used to develop an electrostatic latent image, produces a beautiful one "Blue picture. Simultaneously with the drying of the liquid the colloidal particles making up the image are firmly adhered to the surface of the photoconductive layer and are there in such a state that they cannot be easily removed by rubbing or the like. This is presumably due to the fact that the dimethylaminoethyl methacrylate polymer developed-.ten Gives considerable adhesive power to the image. It is an advantage of this method that you have a developer with such an excellent adhesion.

Example 2

Oil soot 0.2 g -

Penance · '0.5 g

Diethylaminoethyl methacrylate poly " meres 0.3 g

Mixed polymer of acrylic acid and stearyl methacrylate (molar ratio ■

8: 92). 0.6 g

Toluene 2.0 ml

A mixture of the above compounds was found on same way as-treated in example 1 and so a de- '" winder manufactured, this developer gives a clear fine black image and has excellent adhesive properties. If you add 5 g of methyl dihydroabietate to this developer

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the stability of the colloid is improved. Example ^

Oil blue BO. > ; 0.5 g Microlith black CT 0.5 g

• Mixed polymer of diethylaminoethyl methacrylate, styrene and lauryl methacrylate (molar ratio
3: 5: 2) "0.3 g

Mixed polymer of methacrylic acid
and ethylhexyl methacrylate
(4:96 molar ratio) 0.6 g

Toluene 2 ml '

Isoparaffin hydrocarbon 3 ml

The microlith black used in the above mixture CT is a black pigment manufactured by CIBA Products, LTD., Switzerland; as an isoparaffinic hydrocarbon For example, ShellSol 71 is used, which is available from Shell Oil Co., England, or a similar product.

A mixture of the above compounds was treated in the same manner as in Example 1 to prepare a developer. All of the colloidal particles in the developer thus obtained are negatively charged and are excellently dispersed. If this developer is used to develop zinc oxide electrophotographic paper, a negative is obtained; a clear black positive receives "! one from a negative microfilm. Simultaneously with the drying 'of the liquid, the image is fixed without heating would be ^required!. The fixed image is excellent in r

Abrasion resistance. , ') -: -. ο I

Penance ·. 0.5 g

Oil black 0.2 g

Phthalocyanine Blue. 0.1 g

Gilsonite 1.0 g

Mixed polymer from dirnethylaminoethyl methacrylate and styrene

(1: 2 molar ratio) 0.4 g

Mixed polymer of acrylic acid and lauryl methacrylate

(Molar ratio 3: 97) 0.4 g

Toluene 2 ml

Isoparaffin hydrocarbon 3 ml

A mixture of the above compounds was thorough dispersed in an ultrasonic disperser and gradually with an isoparaffin hydrocarbon (e.g. Shellsol. 71) until the total amount was 25 ml. Colloidal resin particles formed during dilution, which contained the pigment particles as cores - ■ 1 ml of the so obtained liquid was diluted in 100 ml of Shellso] /. The dispersion thus obtained was used as a developer. The colloidal particles in the developer are negatively charged. If you use this developer to develop an electrical

static photographic paper with negative original used, thus the developer gives a clear positive image with excellent fixing property although the image is somewhat has low optical density. Practically the same results as above are obtained if instead of the mixed polymer from acrylic acid and lauryl methacrylate (molar ratio 3: 97) a copolymer of methacrylic acid and lauryl methacrylate

acrylate used. If one adds methyl dihydroabietate to the

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When developer is added, the stability of the colloid is increased.
Example 5

Carbon black 0.5 g -;

Qlruß. ■ ^; 0.3. G

Resin-modified maleic acid resin 1.2g!

Low molecular weight polystyrene 2.8 g t

Gopal. '■'. ■ 1.0 g -;

A mixture of the above compounds was ^{heated and melted in an oil bath at 180 °} C. and stirred thoroughly until a homogeneous mixture was obtained. After cooling, the mixture was ground in a mortar. The following compounds were added to the powder obtained *

"■ i: dirnethylaminoäthyrmethacrylat-Polymeres 1.2 g " ■

■ . Mixed polymer of methacrylic acid and .. - - J Iiauryl methacrylate ■ 2.0 g ■ '

· '(Molar ratio 6:94). ..

Isoparaffin hydrocarbon 2.0 g

(e.g. Shellsol 71);

Then the mixture was thoroughly stirred and homogeneously
After a while, while stirring vigorously, an isoparaffin hydrocarbon was added - until the total amount was 30 ml.
Then the mixture was dispersed in an ultrasonic * -
direction dispersed. 1 ml of the liquid thus obtained
was diluted with 100 ml of thin isoparaffinic hydrocarbon
and so make a developer. In this liquid, the pigment particles are not only affected by the above-mentioned thermal *
plastic resin, but are also with the Dimethylamiftoäthylmethacrylatpoiymeren and the Methylacryläure ^ hal-

0 0 9 8 0 9/10 80 '""

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ti gene copolymers coated, and therefore have favorable electrical charge properties and dispersibility. In this developer, the particles have a positive charge on. If the developer is used to develop a zinc oxide electrophotographic paper, a clear positive image with high optical density.

Example_6

50 # toluene solution of a mixed polymer

of diethylaminoethyl methacrylate, styrene

and lauryl methacrylate (molar ratio

3: 5: 2) _ 2.4 g

40 $ toluene solution of a copolymer of methacrylic acid and lauryl methacrylate
(Molar ratio 1:19) 5.0 g

Oil soot FS 0.2 g

Microlite black CT 3.0 g

A mixture of the above compounds was dispersed and then added the following connections:

Methyl dihydroabietate 10.0 g

Aluminum dihydroabietate 20 mg

Shellsol 71 80.0 g

The mixture was placed in an ultrasonic disperser dispersed and then diluted 300 times. The developer thus obtained gave a clear one Positive image with high optical density. Simultaneously with the "drying of the liquid", the image was fixed without heating.

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The developers prepared according to the above-described regulations all have the advantage that the colloidal particles have excellent electrical charge properties and dispersibility and have a clear,. result in a very high-contrast image; the developed images also have excellent fixing properties without that special heating would be required. In addition, you can use a resin-only one create colloidal system; if one · this resin, z ^ B. a dimethylaminoethyl methacrylate-containing copolymer, Torher dyes with a dye, so you can also use a achieve colored developed image.

As can be seen from the above examples, the addition of methyl dihydroabietate or a calcium, Manganese, barium, zinc or aluminum salt of dihydroabietic acid achieved an improvement in the stability of the colloid.

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Claims (11)

- 12 godparents ta η proverbs ι (j). Liquid developer for electrostatic photography, which is made by dispersing (I) an alkylaminomethyl methacrylate-containing polymer, (II) a carboxyl group-containing mixed polymer of acrylic or methacrylic acid and an ester thereof, and (III) a dye in a substantially paraffinic hydrocarbon, - existing dispersion medium was produced. 2. Liquid developer for electrostatic photography, which is obtained by dispersing (I) an alkylaminoethyl methacrylate-containing Polymers, (II) a mixed polymer containing acrylic or methacrylic acid containing oxyl groups and an ester thereof, (III) a dye, and (EV) a dihydroabietate ester all in one essence dispersion medium consisting of paraffinic hydrocarbon, was produced. 3. Liquid developer for electrostatic photography, which is obtained by dispersing (I) a Alkylaminoethyl methacrylate-containing polymers, (II) a dye, and (III) a dihydroabietate ester in one A dispersion medium consisting essentially of paraffinic hydrocarbon was prepared. - 13 - 0 09809/1080 4. Liquid developer according to claims 1, 2 or 3, characterized in that the Alkylaminoäthylmeth-; , Acrylate-containing polymers from Polydialkylaminoäthylmethacry-. laten, copolymers from dialkylaminoethyl methacrylates and styrene, or copolymers of dialkylaminoethyl methacrylates, styrene and alkyl methacrylates. 5. Liquid developer according to claim 4, characterized in that the Polydialkylaminoäthylmethacrylate μ consist of Polymethylaminoäthylmethacrylaten or Polydiäthylaminoäthylmethacrylaten. 6. Liquid developer according to claims 1 or 2, characterized in that the mixed polymer of acrylic or methacrylic acid and an ester thereof contains an alkyl group having 6 or more carbon atoms. 7. Liquid developer according to claims 1 or 2, = ■ characterized in that the mixed polymer of acrylic or methacrylic acid and an ester thereof from a mixed ύ polymer of. Methaxrylic acid and lauryl methacrylate, one Mixed polymers of acrylic acid and lauryl methacrylate, a ' Copolymers of acrylic acid and stearyl acrylate, or a -j Copolymers of methacrylic acid and ethylhexyl methacrylate _: consists. \ 8. Liquid developer according to claims 1, 2-. or 3, characterized in that the dispersion medium consists essentially of a paraffinic hydrocarbon with a resistance value of 10 / Lcm or higher. OO98O9 / 10ÖÖ • - 14 - 9. Liquid developer according to claim 2, characterized in that the dihydroabietate ester of methyl glycerol or diethylene glycol dihydroabietate or a divalent or trivalent salt of dihydroabietic acid consists. 10. Liquid developer according to claims 1 or 2, characterized in that the mixing ratio of the alkylaminoethyl methacrylate-containing Polymers to the copolymer of acrylic or methacrylic acid and an ester thereof is 1/10 -1: 1. 11. Liquid developer according to claims 1 or 2, characterized in that the amount of acid in the copolymer of acrylic or methacrylic acid and an ester thereof is $ 10 or less. 009809/1080