EP0714786B1 - New microcapsules comprising as solvent a terpene derivative or an abietic acid derivative, notably for chemical copy papers and messure sensitive papers coated with such microcapsules - Google Patents

Description

The present invention relates to microcapsules useful in particular for the production of carbonless pressure-sensitive paper containing a solution organic of a hydrophobic compound of interest, in particular a chromogenic agent the solvent of which is at least partly a terpene derivative, abietic acid, or an acid derivative abietic.

The invention also relates to pressure-sensitive paper coated on one side of a layer of such microcapsules and the wad of paper sensitive to pressure comprising at least one paper according to the invention.

Finally, it relates to the use of said microcapsules in different fields such as perfumery, agrifood, agrochemicals.

• une feuille émettrice appelée CB, obtenue par enduction au verso de microcapsules contenant une solution d'agents chromogènes,
• une feuille réceptrice appelée CF, obtenue par enduction au recto d'une couche absorbante et réactive vis-à-vis des agents chromogènes,
• une ou plusieurs feuilles intermédiaires comprenant à la fois les microcapsules au verso et la couche réceptrice au recto que l'on appelle CFB.

A bundle of carbonless pressure sensitive paper includes:

• an emitting sheet called CB, obtained by coating on the back of microcapsules containing a solution of chromogenic agents,
• a receiving sheet called CF, obtained by coating the front with an absorbent and reactive layer vis-à-vis chromogenic agents,
• one or more intermediate sheets comprising both the microcapsules on the back and the receiving layer on the front called CFB.

There are also sheets, called "autonomous", obtained by coating with front of a mixture of microcapsules and receiving layer.

The invention relates generally to CB, CFB and autonomous. The operating principle of carbon-sensitive paper pressure consists in bursting the microcapsules under the pressure of a pen or shock from typewriter or needle dot matrix printer or more generally by all printing processes called "impact". The internal phase contained in the microcapsules thus released flows on the CF receptor layer and the chromogenic agents react with the developer to form the colored image.

• être incolore et inodore,
• présenter un bon pouvoir solvant vis-à-vis des agents chromogènes,
• être inerte chimiquement vis-à-vis des agents chromogènes et vis-à-vis des matériaux utilisés pour former les parois des microcapsules,
• avoir un point d'ébullition élevé et une très faible tension de vapeur à température ambiante,
• être liquide à la température d'utilisation du papier autocopiant (jusqu'à -10°C voir -20°C en hiver),
• présenter la viscosité la plus faible possible afin de faciliter l'écoulement de la phase interne lors de la rupture des capsules,
• avoir une bonne stabilité à la chaleur et à la lumière,
• permettre un taux d'encapsulation élevé,
• permettre un développement rapide et intense des agents chromogènes sur le réactif du feuillet CF,
• donner une bonne solidité à la lumière de l'image obtenue sur le feuillet CF,
• être pratiquement insoluble dans l'eau pour pouvoir être encapsulé,
• être sans danger pour le corps humain et pour l'environnement,
• présenter une biodégradabilité élevée,
• avoir un prix faible compatible avec les prix actuels du papier autocopiant chimique.

The solvent used to prepare the internal phase plays a key role in the final quality of the product. It must meet the following requirements:

• be colorless and odorless,
• have good solvent power with regard to chromogenic agents,
• be chemically inert vis-à-vis the chromogenic agents and vis-à-vis the materials used to form the walls of the microcapsules,
• have a high boiling point and a very low vapor pressure at room temperature,
• be liquid at the temperature of use of carbonless paper (down to -10 ° C see -20 ° C in winter),
• have the lowest possible viscosity in order to facilitate the flow of the internal phase during the rupture of the capsules,
• have good heat and light stability,
• allow a high encapsulation rate,
• allow rapid and intense development of chromogenic agents on the reagent of the CF sheet,
• give good light fastness to the image obtained on the CF sheet,
• be practically insoluble in water so that it can be encapsulated,
• be safe for the human body and the environment,
• exhibit high biodegradability,
• have a low price compatible with current prices for carbonless carbon paper.

Currently, among the solvents commonly used, there may be mentioned hydrogenated terphenyls, alkylnaphthalenes, alkylbiphenyls, diarylmethane derivatives, dibenzylbenzene derivatives, paraffins chlorinated, this list is not exhaustive. These solvents are most often mixed with thinners such as kerosene, mineral oils light or alkylbenzenes (for example dodecylbenzene) etc ...

All of these products meet all requirements fairly well set out above except the last regarding biodegradability and non-toxic to the environment hence a risk of pollution during the use and destruction of carbonless chemical papers.

The published document EP-A-0 674 942 mentions among a list of solvents, terpene derivatives for the realization of microcapsules containing a hydrophobic solvent. EP-A 0 674 942 constitutes the state of the art according to Article 54 (3) (4) EPC.

US Patent 4,342,473 relates to a CF reagent (sheet particular). Remember that a bundle of carbonless paper chemical includes a CB layer based on microcapsules such as those described in the present invention and a so-called CF receiving layer. After rupture of the microcapsules, the color formers react with the reagents contained in the CF layer to form the colored image.

As the CF reagent, it is well known that one can use phenols or phenolic resins. The originality of this patent is based on the use of esters of these phenols (or phenolic resins) which esters are not reactive towards color trainers, so it becomes possible to mix reagent and formers in the same solution color and then encapsulate the solution obtained. After rupture of microcapsules, these esters hydrolyze in the presence of moist air to restore the phenol (or phenolic resin) reactive towards the trainers of color hence the formation of the colored image.

The solvents used in this case can be all the solvents usable in the chemical carbonless (cf. col. 7, lines 14 to 27), the terpenes such as turpentine (turpentine). This patent indicates that the preferred solvents include alkylated naphthalenes.

To overcome these defects, it was considered to use the original solvents natural such as vegetable oils (soy, rapeseed, olive, peanut, corn, sunflower, copra, sesame, castor, palm, palm kernel, babassu, jojoba, etc.) especially in the US patents 2,712,507, 2,730,457, 3,016,308, 4,783,196, 4,923,641 and European patent applications 86,636,155 593, 262 569.

1) une émulsification, de la phase interne dans l'eau, très difficile avec à la fin une courbe granulométrique très étalée (présence de particules fines ≤1 µm et de particules grossières de diamètre supérieur à 8 µm). Ce défaut se traduit en pratique par une perte de rendement en duplication liée aux petites capsules et un papier trop sensible au stockage en pile et aux différentes manipulations à cause des grosses capsules (bleuissement ou noircissement prématuré du papier avant utilisation) et en particulier lors du passage sur les machines d'impression,

2) une viscosité trop élevée (mauvais écoulement de la phase interne d'où une perte de rendement),

3) une révélation insuffisante des agents chromogènes en présence d'huile végétale (duplication d'intensité faible), notamment pour les dérivés de fluorane ou de phtalide.

4) des tenues au vieillissement insuffisantes pour les papiers CB, CFB et autonomes en particulier en atmosphère humide et chaude (coloration bleue ou noire des papiers avant utilisation),

5) une tenue insuffisante à la lumière de l'image colorée sur CF,

6) une biodégradabilité souvent insuffisante.

None of these vegetable oils gives satisfactory results, because in all cases we observe:

1) an emulsification, of the internal phase in water, very difficult with at the end a very spread granulometric curve (presence of fine particles ≤1 μm and coarse particles of diameter greater than 8 μm). This defect is reflected in practice by a loss of duplication yield linked to small capsules and a paper that is too sensitive to stack storage and to various manipulations because of large capsules (premature blueing or blackening of the paper before use) and in particular during passage on printing machines,

2) too high a viscosity (poor flow of the internal phase resulting in a loss of yield),

3) insufficient revelation of the chromogenic agents in the presence of vegetable oil (low intensity duplication), in particular for fluorane or phthalide derivatives.

4) insufficient aging resistance for CB, CFB and autonomous papers, in particular in a humid and hot atmosphere (blue or black coloring of the papers before use),

5) insufficient resistance to light in the colored image on CF,

6) often insufficient biodegradability.

Indeed, we have now found that other biodegradable solvents, of natural origin, can be used advantageously instead of oils vegetable, these are terpene derivatives from wood, citrus peel, etc. and abietic acid derivatives obtained from rosin for example.

The object of the present invention relates to new microcapsules and subsequent carbonless papers to overcome the drawbacks described above.

• 10 à 100 % d'au moins un dérivé terpénique choisi dans le groupe constitué par les sesquiterpènes, les alcools terpéniques, les esters terpéniques, les aldéhydes terpéniques, les cétones terpéniques, leurs dérivés hydrogénés, l'acide abiétique, les dérivés estérifiés de l'acide abiétique, les dérivés hydrogénés de l'acide abiétique ou les produits de polymérisation de l'acide abiétique,
• 0 à 80 % d'huile végétale ou d'ester d'acide gras,
• 0 à 80 % d'huile minérale.

The invention therefore firstly relates to microcapsules which are useful in particular for carbonless pressure-sensitive paper, containing an organic solution comprising a compound of hydrophobic interest and a solvent, characterized in that the solvent comprises in percentage by weight:

• 10 to 100% of at least one terpene derivative chosen from the group consisting of sesquiterpenes, terpene alcohols, terpene esters, terpene aldehydes, terpene ketones, their hydrogenated derivatives, abietic acid, esterified derivatives of l abietic acid, the hydrogenated derivatives of abietic acid or the polymerization products of abietic acid,
• 0 to 80% vegetable oil or fatty acid ester,
• 0 to 80% mineral oil.

• les sesquiterpènes tels que le longifolène, l'α-cédrène, l'α- et le β-caryophyllène, le nérolidol, le farnésol, etc.
• les alcools terpéniques tels que les terpinéols, les dihydroterpinéols, le myrcénol, le dihydromyrcénol, le géraniol etc.
• les esters des alcools terpéniques précités, tels que l'acétate de terpényle, l'acétate de géranyle, l'acétate de myrcényle, le formiate de myrcényle, l'acétate de dihydroterpényle etc.

Among these terpene derivatives, there may be mentioned:

• sesquiterpenes such as longifolene, α-cedrene, α- and β-caryophyllene, nerolidol, farnesol, etc.
• terpene alcohols such as terpineols, dihydroterpineols, myrcenol, dihydromyrcenol, geraniol etc.
• esters of the above-mentioned terpene alcohols, such as terpenyl acetate, geranyl acetate, myrcenyl acetate, myrcenyl formate, dihydroterpenyl acetate, etc.

The term "abietic acid derivatives" broadly encompasses esterified derivatives, hydrogenated in particular or products polymerization of abietic acid.

• l'acide abiétique dihydrogéné et ses esters,
• l'acide abiétique tétrahydrogéné et ses esters,
• les polymères d'acide abiétique et leurs dérivés.

Among the abietic acid derivatives, there may be mentioned the esters obtained from abietic acid, as well as:

• dihydrogenated abietic acid and its esters,
• tetrahydrogenated abietic acid and its esters,
• abietic acid polymers and their derivatives.

Liquid products at room temperature are preferred.

In the case of abietic acid derivatives, the methyl esters of dihydroabietic acid are advantageous.

In a broad sense, abietic acid and derivatives of abietic acid could be considered as derivatives of terpenes since they are diterpenes.

Terpene derivatives, abietic acid and derivatives of abietic acid may be present alone or mixed.

Compared to microcapsules containing oil-based solvents vegetable, the microcapsules according to the invention have numerous advantages, in particular better storage stability, better UV resistance, better revelation of chromogenic agents, and in most cases a higher encapsulation rate.

Compared to microcapsules containing conventional solvents, of origin petroleum, mentioned above, the microcapsules according to the invention have the advantage of being biodegradable. These are products of natural origin whose source is renewable. They are safe for the environment (uses common in pharmacy, cosmetics and especially in perfumery).

Compared to microcapsules containing vegetable oils, microcapsules according to the invention have the advantage of better resistance to cold, less coloring, more pleasant odor, greater coloring power, taking into account the solvent power of terpene compounds and smaller diameter dispersion.

The invention relates in particular to the microcapsules containing in solution products such as: chromogenic agents, perfumes, aromas, products food or pharmaceutical, pesticides, biocides, fungicides, herbicides, dyes, catalysts, chemical reagents.

Among the chromogenic agents used, mention may be made, by way of indication, of phthalic derivatives such as 3,3 bis (4-dimethylamino-phenyl) -6-dimethylaminophthalide (CVL) and 3.3 bis (1-octyl-2-methylindole -3-yl) phthalide or fluorane derivatives such as 2-anilino-3-methyl-6-dialkylamino-2 '- (N'-ethyl-N-phenylamino-4'-methylfluorane) or 2'- anilino -3'methyl -6 diethylamino fluorane, 6'-dimethylamino-2 '(N-ethyl-N-phenylamino-4'methylfluorane), 3'-chloro-6'-cyclohexylaminofluorane or 3.7 bis (dimethylamino) -10-benzoylphenotiazine (BLMB) and the compounds of bisarylcarbazolylmethane. This list is not exhaustive and can be extended to all the chromogenic substances commonly used in the art under consideration.

The solution of chromogenic agent in the solvent is around 5% by weight.

Among the microcapsules, it will be advantageous to mention, but not exclusively, those formed of a cross-linked gelatin wall.

These terpene or abietic acid derivatives or abietic acid can be used alone or in mixtures with each other, or with conventional solvents or with vegetable oils.

Among the conventional solvents commonly used, mention may be made of hydrogenated terphenyls, alkylnaphthalenes, alkylbiphenyls, derivatives of diarylmethane, dibenzylbenzene derivatives, chlorinated paraffins, etc.

These solvents are most often mixed with diluents such as kerosene, light mineral oil or alkylbenzene (e.g. docecylbenzene) etc.

Vegetable oils are those commonly used, such as soybean, rapeseed, olive, flax, peanut, palm kernel, corn, sunflower, copra, sesame, castor oil, palm, babassu, jojoba etc., especially in American patents 2,712,507, 2,730,457, 3,016,308, 4,783,196, 4,923,641 and patent applications European No. 86 636, 155 593, 262 569. It is also possible to use the triglycerides called from the Anglo-Saxon term "tall oil" comprising a strong proportion of glycerol trioleate.

These vegetable oils can advantageously be partially replaced or entirely by fatty acid esters.

They generally come from the hydrolysis of vegetable oil followed separation of the fatty acids obtained then esterification

According to a variant, it is possible to carry out a transesterification. The transesterification is the chemical operation which consists in exchanging in an acid medium or basic glycerol by a monoalcohol or dialcohol, in general with short chain, which leads to the formation of a mono- or di-ester.

et d'un reste d'alcool R-O, avantageusement en C₁ à C₈. Parmi les restesThe fatty acid esters are formed from a fatty acid residue

and a residue of alcohol RO, advantageously in C ₁ to C ₈ . Among the remains

alcohols, mention may be made of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, 2-ethylhexanol.

The fatty acid hydrocarbon chain can be saturated or unsaturated, branched or linear. The length of the remaining fatty acid can vary from 3 to 20 carbon atoms.

Preferably, the fatty acid ester is saturated.

However, it has been found that in order to optimally satisfy all the points set out above, it is preferable to use the C ₈ to C ₁₆ fatty acid residues.

Among the remains of saturated fatty acids, there may be mentioned as limiting the remains of lauric, myristic, palmitic acid.

But other remains of saturated fatty acids could also be contemplated, for example, remains of branched fatty acids.

According to a preferred variant, the solvent only comprises one or several terpene derivatives and / or one or more abietic acid derivatives and / or abietic acid.

According to a second variant, the solvent comprises one or more compounds chosen from abietic acid, terpene derivatives and / or abietic acid mixed with one or more mineral oil (s) and / or one or more oils vegetable or fatty acid ester (s).

According to a first preferred variant, the solvent comprises 20 to 80% of terpene derivatives of abietic acid or abietic acid derivatives and 80 to 20% mineral oil.

• 20 à 80 % d'acide abiétique de dérivés terpéniques et/ou de dérivés d'acide abiétique,
• 80 à 20 % d'huile végétale ou d'ester d'acides gras.

According to a second variant, the solvent comprises in percentage by weight:

• 20 to 80% abietic acid of terpene derivatives and / or abietic acid derivatives,
• 80 to 20% vegetable oil or fatty acid ester.

• 10 à 60 % d'acide abiétique de dérivés terpéniques et/ou de dérivés d'acide abiétique,
• 10 à 60 % d'huile végétale ou d'ester d'acides gras,
• 10 à 60 % d'huile minérale.

According to a third variant, the solvent comprises:

• 10 to 60% abietic acid of terpene derivatives and / or abietic acid derivatives,
• 10 to 60% vegetable oil or fatty acid ester,
• 10 to 60% mineral oil.

According to a preferred variant the solvent comprises at least 10% of abietic acid or of derivatives terpenics or abietic acid derivatives, 0 to 50% of a vegetable oil or fatty acid ester and 0 to 70% of a mineral oil.

Preferably a saturated fatty acid ester (capric acid, lauric acid, myristic acid, palmitic acid, stearic acid) or a mixture of esters obtained by transesterification from a vegetable oil, by example, rapeseed methyl ester, soy isopropyl ester, palmitate isopropyl, methyl oleate, 2-ethylhexylcocoate, methyl isostearate, propylene glycol caprate / dicaprylate and as mineral oil is an oil paraffinic is a hydrogenated naphthenic oil.

• les sesquiterpènes tels que le longifolène, l'α-cédrène, etc et leur mélange comme par exemple l'huile M de la société DRT,
• les alcools terpéniques purs tels que l'α-terpinéol et le β- terpinéol, le dihydroterpinéol, le myrcénol, le tétrahydromyrcénol, etc,
• les mélanges d'alcool terpéniques tels que ceux commercialisés sous les marques Terpinéols, Dertol, Nopol par la société DRT.
• les esters tels que l'acétate de terpényle, l'acétate de nopyle, l'acétate de géranyle, l'acétate de menthanyle.

Among the terpene derivatives, the preferred products are:

• sesquiterpenes such as longifolene, α-cedrene, etc. and their mixture such as, for example, oil M from the company DRT,
• pure terpene alcohols such as α-terpineol and β-terpineol, dihydroterpineol, myrcenol, tetrahydromyrcenol, etc,
• mixtures of terpene alcohol such as those sold under the brands Terpinéols, Dertol, Nopol by the company DRT.
• esters such as terpenyl acetate, nopyle acetate, geranyl acetate, menthanyl acetate.

Preferred products are terpineols, nopol, acetate terpenyl, nopyle acetate, sesquiterpenes. Among the acid derivatives abietic, these are the methyl esters of dihydroabietic acid such as products marketed by Herculès under the brands Abalyn E, Hercolyn DE, Metalyn 200.

The invention also relates to a process for the preparation of such microcapsules.

According to a general process, an emulsion of a phase is formed hydrophobic consisting of an organic solution as described previously, in an aqueous phase comprising several colloids including gelatin and one or more other anionic colloids, including may mention carboxymethylcellulose (CMC) and an anhydride copolymer maleic such as a copolymer of ethervinylmethyl and anhydride maleic (PVMMA) or a copolymer of ethylene and anhydride maleic (EMA).

Then the temperature is raised and one proceeds to co-preservation of the emulsion by adding an appropriate acid, in particular acetic acid in order to adjust the pH to around 4. Liquid-walled microcapsules thus constitute by formation of the coacervate around the oil droplets emulsified. Cooling the mixture down to around 10 ° C causes solidification of the liquid coacervate walls.

Then a curing agent such as formalin or glutaraldehyde in order to crosslink said solid coacervate walls and obtain the desired microcapsules.

It is then possible to add binders and other ingredients classics adapted to the suspension of microcapsules to obtain a coating composition for pressure sensitive paper.

• formation d'une suspension dans une phase aqueuse acide de particules constituées de gouttelettes de la solution organique décrite précédemment, lesdites gouttelettes étant revêtues d'un coacervat formé de gélatine, d'un premier colloïde anionique constitué par l'acide polyacrylique et d'un second colloïde anionique constitué par de la carboxyméthylcellulose, et lesdites particules ayant un diamètre de 1 à 12 µm environ, de préférence de 3 à 8 µm,
• refroidissement pour solidifier la paroi,
• réticulation de la gélatine pour fixer la structure et rendre le processus irréversible,
• réchauffement et neutralisation.

According to a particular process described in application EP-A-0 674 942, the following steps are carried out:

• formation of a suspension in an acidic aqueous phase of particles consisting of droplets of the organic solution described above, said droplets being coated with a coacervate formed of gelatin, a first anionic colloid consisting of polyacrylic acid and a second anionic colloid consisting of carboxymethylcellulose, and said particles having a diameter of approximately 1 to 12 μm, preferably 3 to 8 μm,
• cooling to solidify the wall,
• crosslinking of gelatin to fix the structure and make the process irreversible,
• warming and neutralization.

It has been noted that with organic solutions of chromogenic agents according to the invention, the emulsions obtained were more stable and exhibited a narrower grain size curve than emulsions prepared with solvents based on virgin oils.

The emulsion obtained is of the oil in water type and contains droplets of the hydrophobic phase whose diameter is between 1 and 12 micrometers (preferably 3 to 8 micrometers).

Of course, other methods can also be used without departing from the scope of the present invention.

• un procédé à base de gélatine par coacervation complexe tel que celui décrit dans l'exemple 1 où dans les brevets US 4 402 856, FR 2 458 313, EP 339866,
• un procédé à base de résine mélamine-formol comme ceux décrits dans les brevets US 4 406 816, 4 444 699 et 4 898 696 ou EP 319 337 et EP 444559,
• un procédé à base de polyurées ou polyuréthannes comme ceux décrits dans les brevets FR 2 591 124 et US 4 668 580, 4 785 048, 4 898 780 et 5 075 279,
• ou tout autre procédé d'encapsulation connu pour la fabrication de microcapsules servant à la fabrication du papier autocopiant chimique.

Among these other processes, mention may be made of:

• a gelatin-based process by complex coacervation such as that described in Example 1 or in US Patents 4,402,856, FR 2,458,313, EP 339866,
• a process based on melamine-formaldehyde resin such as those described in US Patents 4,406,816, 4,444,699 and 4,898,696 or EP 319,337 and EP 444,559,
• a process based on polyureas or polyurethanes such as those described in the patents FR 2 591 124 and US 4 668 580, 4 785 048, 4 898 780 and 5 075 279,
• or any other known encapsulation process for the manufacture of microcapsules used for the manufacture of chemical carbonless paper.

The microcapsules obtained are mixed with binders starch or latex, a spacer, usually calibrated wheat starch and various additives such as optical brightener, water retentive etc.

They are then laid down on a paper support.

The subject of the invention is also a paper sensitive to the pressure coated on one side with a layer of microcapsules such as have been described previously.

This paper support constituting the transmitting sheet, called CB, of a grammage generally between 40 and 90 g / m2 has been coated with coating the suspension of microcapsules and then these microcapsules were dried to obtain the paper according to the invention.

The coating method and the formulation of the coating bath are not critical to the invention.

The subject of the invention is also a wad of paper sensitive to pressure comprising as described in the preamble to the present description a transmitting sheet and a receiving sheet, and possibly one or more intermediate sheets (CFB) and also so-called autonomous sheets obtained by coating the front of a mixture of microcapsules and receptor layer.

The CF receiving paper associated with the CB sheet is preferably "activated clay" type as described in French patents 2,581,350 or US 4 422 670, but you can also use a phenolic type CF receiving paper such as those described in US Patents 4,559,242 or 4,769,305, or a CF of the type zinc salicylate.

The use of the solvent according to the invention makes it possible to further improve viscosity and quality of the emulsion, the rate of encapsulation in a way quite surprising, but also the intensity and the lightfastness of writing.

In addition, the accelerated aging tests for CB sheets, either dry heat or wet heat are improved.

The invention is illustrated by the following examples:

Example 1

In 1.2 l of deionized water at 40 ° C., an introduced with stirring 55 g gelatin with a bloom value of around 160. It is heated between 40 and 50 ° C until the gelatin is completely dissolved, then 18 g of a solution are added. 50% sodium polyacrylate (molar mass = 1800) and 10 drops of soda.

• 845 g de terpinéol de chez DRT (mélange d'α et γ terpinéol)
• 21 g de noir ODB2
• 9 g de noir S205
• 3,8 g de bleu CVL
• 3,5 g de bleu Pergascript SRB
• 4,2 g d'orange Pergascript 15R.

In parallel, a hydrophobic organic phase is prepared, by heating between 100 and 130 ° C for one hour, of the following mixture:

• 845 g terpineol from DRT (mixture of α and γ terpineol)
• 21 g ODB2 black
• 9 g of black S205
• 3.8 g CVL blue
• 3.5 g blue Pergascript SRB
• 4.2 g of orange Pergascript 15R.

The organic phase and the aqueous phase are mixed with stirring and emulsified using an Ultra-TURRAX type device until obtaining particles with an average diameter of between 5 and 6 μm (the diameter measurement is carried out using a Coulter laser granulometer LS100).

Then mixed in a thermostatic reactor, provided with a agitator, the emulsion obtained previously and a solution of 17 g of carboxymethylcellulose in 625 ml of deionized water. The carboxymethylcellulose has a degree of substitution of the order of 0.8 and a viscosity in 3% aqueous solution at 20 ° C between 60 and 100 mPas measured using a Haake VT 181 viscometer with MVI coaxial cylinders at 180 rpm.

The temperature is raised to 60 ° C. and acetic acid is added in 30 minutes to adjust the pH to 4.3.

1ère étape : addition de 17 g de glutaraldéhyde à 50% sous forte agitation,

2ème étape : addition 4 heures plus tard de 66 g d'une solution à 26% d'alun de chrome. On maintient la température a 8°C pendant 16 heures ainsi qu'une bonne agitation avant de remonter le pH a 7 à la température de 20°C,

The coacervate is cooled to 8 ° C. and this temperature is maintained for 10 hours. The hardening of the walls is carried out in two stages:

1st stage: addition of 17 g of 50% glutaraldehyde with vigorous stirring,

2nd stage: addition 4 hours later of 66 g of a 26% solution of chromium alum. The temperature is maintained at 8 ° C for 16 hours as well as good stirring before raising the pH to 7 at the temperature of 20 ° C,

Example 2

Example 1 is reproduced by replacing the terpineol with β terpineol from DRT (mixture of terpineols comprising more than 70% of β-terpineol),

Example 3

Example 1 is reproduced by replacing the terpineol with α-terpineol from DRT (mixture of terpineols comprising more than 85% of α-terpineol).

Example 4

Example 1 is repeated, replacing the terpineol with oil pine from DRT (trademark DERTOL 90)

Example 5

Example 1 is repeated, replacing the terpineol with terpinolene from DRT (mixture of terpene derivatives comprising at least minus 95% of 1-4 (8) paramenthadiene).

Example 6

Example 1 is reproduced by replacing terpineol with nopol from DRT (mixture of terpene alcohols consisting essentially of 6,6-dimethyl- (3,1,1), bicyclo -2-heptene -2-ethanol.)

Example 7

Example 1 is reproduced by replacing the terpineol with terpenyl acetate from DRT

Example 8

Example 1 is reproduced by replacing the terpineol with a 50/50 mixture of terpineol and light naphthenic oil NYTEX 800.

Example 9

Example 8 is repeated, replacing the terpineol in the mixture with terpenyl acetate.

Example 10

Example 8 is reproduced by replacing Terpineol with nopol.

Example 11

Example 8 is reproduced by replacing Terpineol with Abalyn E from Hercules (methyl ester of dihydroabietic acid).

Example 12

Example 1 is reproduced by replacing Terpineol with a 50/50 mixture of Terpineol and coconut oil.

Example 13

Example 1 is reproduced by replacing Terpineol with a 50/50 mixture of terpenyl acetate and 2 ethyl hexyl laurate.

Example 14

Example 12 is repeated, replacing the coconut oil of the mixing with 2-ethylhexyl laurate.

Example 15

Example 1 is reproduced by replacing Terpineol with a 30/30/40 ternary mixture of Terpineol / coconut oil / naphthenic oil slight.

Example 16

Example 15 is repeated, replacing the Terpineol in the mixture ternary with terpenyl acetate.

Example 17

Example 15 is repeated, replacing the Terpineol in the mixture ternary with M oil from DRT (mixture of sesquiterpenes).

Example 18

Example 1 is reproduced by replacing Terpineol with a 10/50/40 ternary mixture of Terpineol / 2-ethyl-hexyl laurate / oil light naphthenic.

Example 19

Example 1 is reproduced by replacing Terpineol with a 20/50/30 ternary mixture of Terpineol / 2-ethyl-hexyl laurate / norpar 12 (paraffinic oil).

Example 20

Example 1 is reproduced by replacing the terpineol with a 25/25/50 ternary mixture of Abalyn E / coconut oil / Norpar 12

Comparative examples

Comparative example n ° 1: Example 1 is reproduced by replacing the Terpineol with refined coconut oil

Comparative example n ° 2: Example 1 is reproduced by replacing the Terpineol by a 50/50 mixture of coconut oil / light naphthenic oil

Results

• Le contrôle de la granulométrique est effectué à l'aide d'un granulomètre à laser (Coulter LS 100). On détermine le diamètre moyen et la dispersion en taille caractérisée par la variance.
• La viscosité est mesurée a l'aide d'un viscosimètre HAAKE VT 181 avec mobile MV1.
• Le taux de matières sèches est mesuré à l'aide d'un dessicateur à infrarouge (la phase interne est comptée comme matière sèche).
• Le taux d'encapsulation est mesuré par couchage des microcapsules sur un papier CF puis écrasement sous 500 bars de pression sur la moitié de la feuille. On mesure ensuite la différence de densité optique entre la partie écrasée et la partie non écrasée à l'aide d'un densitomètre MACBETH RD 914.

The checks carried out on the microcapsules as well as on the CB papers obtained by coating these microcapsules are collated in the table below.

• The particle size control is carried out using a laser granulometer (Coulter LS 100). The mean diameter and the size dispersion characterized by the variance are determined.
• The viscosity is measured using a HAAKE VT 181 viscometer with mobile MV1.
• The dry matter content is measured using an infrared desiccator (the internal phase is counted as dry matter).
• The degree of encapsulation is measured by coating the microcapsules on CF paper and then crushing under 500 bar of pressure on half of the sheet. The difference in optical density between the crushed part and the non-crushed part is then measured using a MACBETH RD 914 densitometer.

• La sensibilité au maculage sous faible pression. On écrase une liasse (CB + CF) sous 50 bars puis on mesure la perte de blancheur du CF a l'aide d'un réflectomètre Docteur Lange.
• La réactivité du CB par écrasement à la calandre d'une liasse (CB + CF) est effectuée par la mesure de la densité optique de la coloration obtenue après une heure d'attente à l'abri de la lumière.
• La résistance à la lumière de l'écriture est effectuée par exposition de celle-ci aux rayons UV (lampe à mercure de 400W). On mesure la chute de la densité optique après 3 heures d'exposition.
• Les vieillissements accélérés des feuillets CB
  • soit en chaleur sèche : 72 heures à 140°C sous un poids de 5 DaN,
  • soit en chaleur humide : 5 jours à 80°C et 80% d'humidité relative sous un poids de 5 DaN ; feuillet CB contre feuillet CF.

These checks are supplemented by a series of tests:

• Sensitivity to smearing under low pressure. A bundle (CB + CF) is crushed under 50 bars and then the loss of whiteness of the CF is measured using a Doctor Lange reflectometer.
• The reactivity of the CB by crushing with a calender of a bundle (CB + CF) is carried out by measuring the optical density of the coloration obtained after one hour of waiting in the dark.
• The resistance to writing light is carried out by exposure to UV rays (400W mercury lamp). The drop in optical density is measured after 3 hours of exposure.
• Accelerated aging of CB sheets
  • either in dry heat: 72 hours at 140 ° C under a weight of 5 DaN,
  • either in humid heat: 5 days at 80 ° C and 80% relative humidity under a weight of 5 DaN; CB slip versus CF slip.

In both cases, the loss of reactivity of the CB is measured by crushing with the grille before and after aging. In addition, in the case of wet heat test, the loss of whiteness of the CF due to the migration of part of the chromogenic agents present in the microcapsules compared to a blank test on the same CF.

The table presented below summarizes the results obtained for the various examples.

Claims (15)

1. Microcapsules of use in particular for pressure-sensitive carbonless copy paper, comprising an organic solution comprising an hydrophobic compound interest and a solvent, characterized in that the solvent comprises, as percentage by weight:

   10 to 100% of at least one terpene derivative chosen from the group consisting of sesquiterpenes, terpene alcohols, terpene esters, terpene aldehydes, terpene ketones, their hydrogenated derivatives, abietic acid, the esterified derivatives of abietic acid, the hydrogenated derivatives of abietic acid or. the polymerization products of abietic acid,

   0 to 80% of vegetable oil or of fatty acid ester,

   0 to 80% of mineral oil.
2. Microcapsules according to Claim 1, characterized in that the solvent comprises, as percentage by weight:

   20 to 80% of at least one terpene derivative chosen from the group consisting of sesquiterpenes, terpene alcohols, terpene esters, terpene aldehydes, terpene ketones, their hydrogenated derivatives, abietic acid, the esterified derivatives of abietic acid, the hydrogenated derivatives of abietic acid or the polymerization products of abietic acid,

   80 to 20% of a fatty acid ester or vegetable oil compound.
3. Microcapsules according to Claim 1, characterized in that the solvent comprises, as percentage by weight:

   20 to 80% of at least one terpene derivative chosen from the group consisting of sesquiterpenes, terpene alcohols, terpene esters, terpene aldehydes, terpene ketones, their hydrogenated derivatives, abietic acid, the esterified derivatives of abietic acid, the hydrogenated derivatives of abietic acid or the polymerization products of abietic acid,

   80 to 20% of mineral oil.
4. Microcapsules according to Claim 1, characterized in that the solvent comprises, as percentage by weight:

   10 to 60% of at least one terpene derivative chosen from the group consisting of sesquiterpenes, terpene alcohols, terpene esters, terpene aldehydes, terpene ketones, their hydrogenated derivatives, abietic acid, the esterified derivatives of abietic acid, the hydrogenated derivatives of abietic acid or the polymerization products of abietic acid,

   10 to 60% of vegetable oil or of fatty acid ester,

   10 to 60% of mineral oil.
5. Microcapsules according to one of Claims 1, 2 or 4, characterized in that the vegetable oils are chosen from the group consisting of soybean, rapeseed, olive, linseed, groundnut, palm kernel, maize, sunflower, coconut, sesame, castor, palm, babassu and jojoba oils.
6. Microcapsules according to one of Claims 1, 2 or 4, characterized in that the esters are chosen from the group consisting of the esters of saturated C₃ to C₂₀, advantageously C₈ to C₁₆, fatty acids, the alcohol residue being a C₁ to C₈ residue.
7. Microcapsules according to one of Claims 1, 2, 4 or 6, characterized in that the fatty acid ester is an ester mixture obtained by transesterification starting from a vegetable oil.
8. Microcapsules according to one of Claims 1, 3 or 4, characterized in that the mineral oils are chosen from the group consisting of hydrogenated terphenyls , alkylnaphthalenes, alkylbiphenyls, diarylmethane derivatives, dibenzylbenzene derivatives, alkylbenzenes, kerosenes, or light aliphatic or naphthenic mineral oils.
9. Microcapsules according to one of the preceding claims, characterized in that the terpene derivative is chosen from the group consisting of terpene alcohols, alone or as a mixture, esters of terpene alcohols, alone or as a mixture, or their partial or complete hydrogenation products, or sesquiterpenes, alone or as a mixture.
10. Microcapsules according to Claim 9, characterized in that the terpene derivative is chosen from the group consisting of α-terpineol, β-terpineol, dihydroterpineol, myrcenol, tetrahydromyrcenol, terpenyl acetate, nopyl acetate, geronyl acetate, menthanyl acetate, longifolene, α-cedrene, α- and β-caryophyllene, or a mixture of sesquiterpenes.
11. Microcapsules according to one of Claims 1 to 8, characterized in that the hydrogenated derivatives of abietic acid are dihydroabietic acid esters.
12. Microcapsules according to one of the preceding claims, characterized in that the hydrophobic of interest is chosen from the group consisting of chromogenic agents, fragrances, flavourings, foodstuffs, pharmaceuticals, pesticides, biocides, fungicides, herbicides, colorants, catalysts or chemical reagents.
13. Microcapsules according to one of the preceding claims, characterized in that the chromogenic agent is chosen from the group consisting of derivatives of the phthalic type, such as 3,3-bis(4- dimethylamino-phenyl)6-dimethylamino-phthalide (CVL) and 3,3-bis(1-octyl-2-methylindol-3-yl)phthalide, or fluoran derivatives, such as 2-anilino-3-methyl-6-dialkylamino-2'-(N'-ethyl-N-phenylamino-4'-methylfluoran) or 2'-anilino-3'-methyl-6-diethylamino-fluoran, 6'-dimethylamino-2'-(N-ethyl-N-phenylamino-4'-methylfluoran) or 3'-chloro-6'- cyclohexylamino-fluoran, or 3,7-bis(dimethylamino)-10-benzoylphenothiazine (BLMB), and bisarylcarbazolylmethane compounds.
14. Pressure-sensitive paper coated on one face with a layer of microcapsule according to one of Claims 1 to 13.
15. Pressure-sensitive paper bundle comprising at least one paper according to Claim 14.