DE1671541A1 - Process and manufacture of pressure-sensitive copier papers - Google Patents

Description

W "13 073/67 13 / Ko

Fuji Shashin movie Käbushiki Kaisha Kanagawa (Japan)

Process for the production of pressure-sensitive copier papers

The invention "relates to a process for the production of pressure-sensitive copier papers and in particular special on a process for the production of an iL "bziell · - paper or a capsule paper (capsule paper) without the occurrence of the complaints or disturbances by a | ce "iZ" exciting smell ,,

If a fax ³ dead _? organic electron donor compound is adsorbed on an electron-absorbing adsorbent, a chemical electron donor * acceptor reaction takes place with the formation of a colored material from the two colorless materials.

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The pressure-sensitive capsule paper used here has a thin layer on its surface in which non-volatile, fine, liquid particles in microencapsulated form, which contain a colorless electron donor compound, are dispersed, the Mirjßokapseln using local pressure, for example by welding by hand with a pencil _? Pen holders or ball pens, or by typing, are capable of tearing open; This pressure-sensitive capsule paper is on a _"set adsorbent or pickup paper, which is feebracht a layer of an adsorbent and a binder, wherein the encapsulation layer into contact with the Adsopptionsmittβίε chicht ,, Subsequently, this arrangement by writing by hand or with the machine locally pressed, whereby color is only formed in the pressed places or parts.

So far, the organic electron donating compound used for the pressure-sensitive capsule paper has been contained in a microcapsule formed from gelatin or gum arabic, and around such a capsule? / asserbe ~ To impart durability and strength, formaldehyde was usually added to the coating composition of the capsule dispersion. This formaldehyde is used to react with the capsules forming material such as gelatin

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the manufacture of pressure sensitive copy paper free? Formaldehyde, de * 'without reaction with gelatin remains applied to cribbing or carrier papers together with the capsules as the coating and accordingly formaldehyde in the • coating step or the subsequent processing ^ - or processing steps to produce a specific, irritation% .erregenden odor evaporates "This irritating odor has a very harmful effect on the health of the workers in the manufacturing plant and is therefore undesirable from a physiological and hygienic point of view."

There have therefore been carried out investigations in order to prevent the vaporization of formaldehyde during the manufacturing process of pressure-sensitive copying papers and eliminate the stimulus causing odor, wherein a method for fixing or binding of the free formaldehyde by transesterification Λ reduction with a reactive with the formaldehyde material found 'became" . .

The object of the invention is therefore to create a method for preventing the generation of the irritant Odor of formaldehyde in the manufacture of pressure-sensitive Copy papers ",

Another purpose of the invention is to provide pressure-sensitive capsule papers which do not give off an irritating odor of formaldehyde _{or the like}

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Another purpose of the invention is to create of a process for the production of pressure-sensitive papers without generating the irritating smell of formaldehyde »

The purposes outlined above are achieved according to the invention by a "method" in which one "in the production of Φοη pressure-sensitive capsule paper using formaldehyde to improve the fasser resistance and the strength of the microcapsules containing the coating composition from the residual free formaldehyde Capsule dispersion sodium sulfite or urea for binding or fixation of the formaldehyde by reacting it with it,

If sodium sulfite or urea the capsule dispersion after the capsules have solidified by adding formaldehyde, the remaining free form becomes - aldehyde, de * not for solidification treatment of the capsules; Has contributed to the implementation with the sodium sulfite or Brought urea with the immediate formation of a crystalline addition product, which fixes the formaldehyde and is retained and in this way the generation of irritating odor as a result of the evaporation of the free Formaldehyde is completely prevented. To sodium sulfite or to convert urea with -B'ormaldehyde in the capsule dispersion ", the temperature and the contact time must be in be regulated in an appropriate manner »

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With the use of sodium sulfite, the remaining formaldehyde may to a sufficient extent with sodium sulfite under the conditions of a pH ^T ^ ert in the range of 6 to 8, Haumtemperatur and a reaction time are reacted for 2 hours "Since sodium sulfite is a .Reduktionsmittel must therefore if Materials that can be easily reduced are present in the system, the amount of sodium sulfite must be increased according to the amount of these materials <= - -

If H, qrn§toff is used, the reaction is acidic State, namely at a pH value of 5 to 5 and in the alkaline state State, namely with a ρΗ-ΐ / ert from 8 to 12 possible « The temperature can range from -30 to -60 G and the reaction time is about 4 hours. ■

The amount of sodium sulfite added is expediently Λ to 13 'moles per 1 mole of remaining formaldehyde and that of urea is 1 to 3 moles of 1 mole of remaining formaldehyde a final stage of the Vefkap'süli'erung "and before the storage of the 'Kapseidisperaiion. in. a 'done supply or storage container, after which the additive with the remaining formaldehyde to adjust the pH "value,'""" (I (~ .r temperature and vice lieaktionsdauer & ow Vi / IRD ₉

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The invention is illustrated below by way of examples explained in more detail

example 1

A suitable amount of an aqueous 10% sodium '

hOdroxydlösüng was added to 100 kg of a capsule dispersion for Copy '

/ Papers with a content of unreacted formaldehyde added to adjust their pH to 8 to 9. 2 mol of urine per 1 mol of the remaining formaldehyde were introduced into this dispersion, followed by stirring for M hours at a temperature of 50.degree caused irritating odor-causing decreases in the coating step, as well as in the subsequent Verarbeitangsstufen and a ^u te ^{r <iem} the properties of diaackempfihdlichen copy paper were good ·

Example 2

Follow the same procedure as described in Example 1, The prepared dispersion was applied to the opposite surface, an adsorbent paper, to produce an intervening piece of paper »The irritating one Odor in the coating stage and in the processing stages was decreased as in the case of Example 1 »The properties from the intermediate paper were also good

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Example 3

In 100 an unreacted formaldehyde kg capsule containing dispersion was added an appropriate amount of a 1Q ^? Acetic acid added to the pH ^ ert 3 regulate to 5 = This dispersion was added 2 moles of H _g rnstoff per 1 mol of residual formaldehyde was added and the System was stirred to dissolve the urea * Then the capsule dispersion was stirred for 4 hours at 3'5 ° O 'When the cape dispersion prepared in this way was applied to paper, the presence of formaldehyde in the coating step was irritating Odor reduced, with the properties of the pressure-sensitive copier paper thus obtained being good »

Example 4

The capsule dispermone prepared by the same procedure as described in Example 3 was applied to the opposite surface of a pressure-sensitive adsorbent paper in order to form a wiping paper '3 reduced «

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Example 5

The pH value of 100 kg of a capsule dispersion was adjusted to 6 Ms 8 and there were 1.5 mol .Natriumsulfit 1 mol of remaining formaldehyde was added each time, whereupon was stirred for 2 hours at room temperature * In this case the reaction of formaldehyde and sodium sulfite increased the pH of the dispersion due to the formation of sodium hydroxide and it was therefore necessary to adjust the pH Reduce the addition of acetic acid to below 10.,? / Enn When the capsule dispersion prepared in this way was applied to a paper, the irritating odor was reduced in the coating stage and the processing stages, whereby the

Copying properties of the pressure-sensitive paper thus obtained

were good »

Example 6

The same procedure as in Example 5 described, produced capsule dispersion was on the opposite surface of an adsorption paper applied, to make a middle or intermediate paper. The irritating smell in the coating stage and the "processing stages" was decreased and the properties of the intermediate * paper were good.

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Claims (2)

Pat e nt to the ρ back 1 "A method for producing pressure-sensitive copying papers, characterized _s that formaldehyde dispersion of a colorless, organic". Elektronendonatorenverbiiidung adding microcapsules containing for producing pressure-sensitive copying papers to solidify, introducing into this sodium sulphite or urea, wherein the additive to react with the remaining free formaldehyde, which did not contribute to the solidification, is brought, and then the resulting dispersion is applied to a paper » 2. The method according to claim 1 _? characterized by "that when using sodium sulphite as an additive, this in a ™ Amount νση 1 to 1.5 mol ge 1 mol of remaining formaldehyde is introduced into the coating mass, 3c method according to claim 1 or 2, characterized in that that the sodium sulfite under the conditions of a pH / ert in the range of -6 to 8 find at about ambient temperature is added «- ~ BADOBtQINAL 2098 0 9- / 04 41 Mv procedure according to. To claim 1, characterized in that the use of urea as an additive of this in a menu;? E of t to 3 mol per 1 mol of residual formaldehyde · is in- which the dispersion containing coating liquid introduced _β 5 = method according to claim 4, characterized in that the urea under any conditions of a pH-7 / ert im Range from 3 to 5 or 8 to 12 and added at a temperature of 30 to 60 C. » £ 09809/0441