US3900218A

US3900218A - Desensitizer composition

Info

Publication number: US3900218A
Application number: US393089A
Authority: US
Inventors: Akio Miyamoto; Hiroharu Matsukawa
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1972-08-30
Filing date: 1973-08-30
Publication date: 1975-08-19
Anticipated expiration: 1992-08-19
Also published as: FR2198416A5; GB1407645A; ES418319A1; DE2343800A1

Abstract

A desensitizer composition for desensitizing a color developer capable of reaction with a substantially colorless color former to form a color containing as a desensitizer at least one of (a) a spiroacetal diamine compound represented by the following general formula:

wherein R represents a hydrogen atom or an alkyl group, and R1 and R2 each represents a straight or branched chain alkylene residue, or (b) the reaction product of said spiroacetal diamine compound with a compound having at least one oxirane ring.

Description

United States ate Miyamoto et 211.

1451 Aug. 19, 1975 DESENSITIZER COMPOSITION [75] Inventors: Akio Miyamoto; Hiroharu Matsukawa, both of Shizuoka, Japan [73] Assignee: Fuji Photo Film (10., Ltd., Minamr Ashigara, Japan 22 Filed: Aug. 30, 1973 21 Appl. No.: 393,089

51 11m. (:1 341m 5/18 [58] Field of Search 117/369; 260/3407 [56] References Cited UNITED STATES PATENTS 2,505,470 4/1950 Green 117/369 2,505,489 4/1950 Green 117/369 2,550,471 4/1951 Green et a1. 1 117/36.9 2,777,780 1/1957 Cormack et a1. 117/364 2,996,517 8/1961 Leech et a1. 260/3407 3,293,060 12/1966 Harbort 117/362 3,609,169 9/1971 Iijima et a1 260/3407 Yoshimura et a1. 1. 260/3407 Yoshimura et a1. 260/3407 Primary E.\'aminerThomas J. Herbert, Jr. Attorney, Agent, or Firm-Sugl11ure, Rothwell, Mion, Zinn and Macpeak 5 7 ABSTRACT A desensitizer composition for desensitizing a color developer capable of reaction with a substantially co1- orless color former to form a color containing as a desensitizer at least one of (a) a spiroacetal diamine compound represented by the following general formula:

wherein R represents a hydrogen atom or an alkyl group, and R, and R each represents a straight or branched chain alkylene residue, or (b) the reaction product of said spiroacetal diamine compound with a compound having at least one oxirane ring.

17 Claims, No Drawings DESENSITIZER COMPOSITION BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to a desensitizer composition and, more particularly, it relates to a desensitizer composition which reduces or cuts down the function of a color developer capable of changing a colorless colorformer into a colored form.

2. Description of the, Prior Art It has long been'known to form colored images by utilizing the contact reaction between a color former which is an almost colorless organic compound and a color developer. For example, such a color-forming reaction is utilized for the group of recording materials illustrated in U.S. Pat. Nos. 2,505,470, 2,505,489, 2,548,366, 2,550,471, etc.; a group of recording materials illustrated in U.S. Pat. Nos. 2,712,507 2,730,456, 2,730,457, 3,293,060, etc.; the group of recording materials illustrated in U.S. Pat. No. 3,666,525, filed on May 26, 1970, British Pat. No. 825,354, etc.; and for recording materials for use in spirit printing, stencil printing, automatic ticket-vending systems, fingerprinttaking systems, letter-writing systems, etc.

In these recording materials, since a color-forming reaction occurs when a color former and a color developer come into contact with each other, it is desirable by some method to prevent the color-forming reaction at the' areas yvhere colored images are unnecessary from the viewpoint of function and economic advantages.

Heretofore, desensitizers have been used for this purpose. For example, there are known U.S. Pat. No. 2,777 ,780 (high molecular weight primary amines such as dodecylamine; quaternary ammonium salts such as dodecyltrimethylammonium chloride; alkylor arylamine acetates), Japanese patent publication No. 29546/71 (monoalkylamines, aralkylamines or tertiary amines wherein ethylene oxide groups are chemically connected to ethanol amine), Japanese patent publication No; 35697/71 (urea resin prepolymer), and others (secondary alkylamines such as didodecylamine; tertiary alkylamines such as triethylamine; primary arylamines such as aniline; aralkylamines such as benzylamine; polyhydroxy compounds such as polyethylene glycol and glycerin).

However, these desensitizers have the disadvantage that'the desensitizing action thereof is insufficient or, if sufficient, a practical effect cannot be obtained unless they are used in a large amount. Therefore, some desensitizers are not sufficiently effective to prevent coloring at the desensitized areas even when they are used in a large amount, while other desensitizers will permit a similar phenomenon unless used in a large amount. In particular, these disadvantages tend to become more serious with improvements in the color for- Therefore, the advantageous properties of these color developers'(for example, color images obtained by using these color developers are not erased with water) are effectively limited. Another disadvantage of conwith a desensitized color developer,

ventional desensitizers is that, when a color former solution enclosed in a wall film is brought into contact the nondesensitized areas of the color developer become colored with the lapse of time (the formation of the socalled desensitization fog).

Furthermore, conventional desensitizing will yellow on the color developer or, where they are used in a large amount, the drying speed is so slow that it is difficult to increase the coating (or printing) speed.

It is, therefore, a primary object of the present invention to provide a desensitizer composition having a strong desensitizing action.

Another object of the present invention is to provide a desensitizer composition having excellent coating properties and capable of being used regardless of whether the coating solution is aqueous or oily.

A further object of the present invention is to provide a desensitizer composition which causes less desensitization fog.

Still a further object of the present invention is to provide a desensitizer composition which exerts no detrimental influences on the color former, the color developer and the system containing these materials.

SUMMARY OF THE INVENTION As a result of extensive investigations, the inventors have found that the objects of the present invention can be attained by using as the desensitizing component at least one of a spiroacetal diamine represented by the following general formula;

CH O R HZNR, O-CI-I CH -O RQNHZ wherein R represents a hydrogen atom or an alkyl group, and R and R each represents-a straight or branched chain alkylene residue or of the reaction product thereof with a compound having at least one oxirane ring.

DETAILED DESCRIPTION OF THE INVENTION Spiroacetal diamines are known compounds and readily be synthesized according to the processes described in, e.g., German patent No. 1,092,029, U.S. Pat. No. 2,996,517, etc. I

The important characteristics of the desensitizers represented by the above general formula is that they possess a spiroacetal structure and amino groups. Therefore, substituents R, R and R are not especially limited in any way. Illustrative examples of these sub-' stituents are as alkyl groups for R, those having 1 to 20 (particularly 1 to 5, especially l to 2) carbon atoms, such as methyl, ethyl, propyl or the like. The straight or'branched chain alkylene residues represented by R and R are those having 1 to 20 (particularly 1 to 6)' ane, 3,9-bis(2-aminoethyl)-2,4,8, l -tetraoxaspiro[ 5,- ]undecane, 3 ,9-di-ethyl-3 ,9-bis( 2-aminoethyl 2,4,8,l0-tetraoxaspiro[5,5]undecane, 3,9-bis(3- aminopropyl)-2,4,8 l 0-tetraoxaspiro[5 ,5 ]undecane, 3,9-bis(4-aminobutyl )-2 ,4,8 1 0-tetraoxaspiro[ 5 ,5 ]undecane, 3,9-bis( S-aminopentyl )-2,4,8, 1 0-tetraoxaspiro[5,5 ]undecane, or 3,9-bis( l,l-dimethyl-4- aminobutyl )-2,4,8 l 0-tetraoxapsiro[5 ,5 ]undecane,

and the like.

It has been stated above that the compounds of the present invention include both the spiroacetal diamine compounds per se and the reaction products thereof with a compound having at least one oxirane ring. With respect to the spiroacetal compounds per se, they show a desensitizing effect when used in a lower amount as compared with conventional desensitizing compounds. As a basis for comparison, the compounds of the invention exhibit sufficient desensitizing effect in an amount at least A; (by weight) that of the amount required for conventional desensitizers. Of course, the desensitizing compounds of the present invention can be used in greater amounts. For example if used at a level greater than /a the amount conventionally used for known desensitizing compounds the compounds of the invention provide desensitizing effect. The aforesaid value of V; the amount used for conventional desensitizing compounds is based only on economic considerations. On the other hand, when the compound of the present invention is used in an amount less than A: that employed for conventional desensitizers, the effect thereof is reduced proportionally to the decrease in the amount, but more excellent effects can still be provided in such case as compared with the same amount of known desensitizers, such as the conventional desensitizers as disclosed in U.S. Pat. No. 2,777,780. Generally, the compound of the present invention is applied in an amount of from about 0.5 to glm preferably l to 5 g/m found that the desensitizing effect of the spiroacetal diamine compound per se can be further improved and the desensitization fog can be removed by reacting the spiroacetal diamine with a compound having at least one oxirane group in its molecule.

Where desired mixtures of the spiroacetal diamine compound per se and the reaction product of the spiroacetal compound with the compound having at least one oxirane ring can be used where desired.

To illustrate compounds having at least one oxirane group in the molecule, there are alkyl glycidyl esters such as propyl glycidyl ether, butyl glycidyl ether, etc.; allyl glycidyl ethers such as Epikote 828, 834 or 1001 (trade name, made by Shell International Chemicals Corp.), etc.; alkylene oxides such as octylene oxide, styrene oxide, ethylene oxide, propylene oxide, epoxidized polybutadiene, etc.; alicyclic epoxides such as vinyl-cyclohexene dioxide, 3,4-epoxy-6-methylcyclohexylmethyl, 3,4-epoxy-6-methylcyclohexanecarboxylate, etc.; epoxidized vegetable oil fatty acids such as epoxidized oleic acid, epoxidized linoleic acid and epoxidized linolenic acid, epoxidized glycerides obtained by the action of a peracid on an unsaturated fatty acid glyceride such as epoxidized oleic acid glyceride, etc.; and the like.

The reaction between the spiroacetal diamine and the oxirane group-containing compound can be conducted by mixing both reactants, e.g., in a 1:1 molar ratio, and heating the mixture to a temperature higher than the melting point of the spiroacetal diamine component, c.g., 30 to 150C, preferably 100 to 130C. However, in this reaction, it is not necessary to react the oxirane group and the amino group in equivalent amounts, and the reaction can be conducted using one or other of the reactants in excess and the product can also be employed in this invention, e.g., since the spiroacetal diamine compound per se is a desensitizer, an excess of this compound can be present in the reaction product mixture. The reaction product obtained of the spiroacetal diamine and the compound having at least one oxirane ring has preferably a molecular weight of 200 to 3,000. The reaction can be conducted both in the presence or absence of a solvent. Since both reactants are liquid, the reaction proceeds both in the presence and absence of a solvent. If a solvent is used, organic solvents having a boiling point of to 120C are preferred. When the solvent has a boiling point of lower than C, it is dangerous from a practical standpoint. When the solvent has a boiling point of higher than C, evaporation of it and solvent removal becomes extremely difficult.

Typical examples of suitable solvents are methanol, ethanol, benzene, toluene, xylene, etc.

All that is required for the desensitizer composition of the present invention is that the composition contain at least one of the above described spiroacetal diamines as the desensitizing component. The other components of the composition are not particularly limited at all. The other components as used herein include those which are incorporated in conventional desensitizer compositions. The composition can contain natural or synthetic high molecular weight compounds (e.g., ketone resins, polyamide resins, maleic acid resins, fumaric acid resins, phenol resins, epoxy resins, alkyd resins, melamine resins, urea resins, acryl resins, nitrocellulose, butyral resins, methyl cellulose, cellulose acetate butyrate, casein, gelatin, polyvinyl alcohol, etc.). In many cases, these high molecular weight materials are used as a binder, but the purpose thereof is not necessarily be limited thereto. The composition also can contain pigments (e.g., titanium oxide, zinc oxide, barium sulfate, magnesium carbonate, calcium carbonate, barium carbonate, magnesium hydroxide, talc, etc.) to improve printing property, whiteness and hiding power; glycols (e.g., ethylene glycol, diethylene glycol, glycerin, polyethylene glycol, polypropylene glycol, etc.); solvents (e.g., alcohols, etc.); fats and oils (e.g., paraffin, Japan wax, etc.) to improve friction resistance; drying oils (e.g, linseed oil, tung oil, soybean oil, etc.); semi-drying oils (e.g., cotton seed oil, rapeseed oil, rice bran oil, etc.); and, in some cases, conventionally known additives such as starch or like off settingpreventing agents, other desensitizers, etc. as disclosed in Chapters 23 to 24 of E. A. Apps, Printing lnk Technology published by Leonard Hill Ltd. London (1961). The binders are generally used in an amount of 5 to 30 wt%, pigments in an amount of 5 to 50 wt%, glycols, solvents, fat and oils, drying oils, semi-drying oils each in an amount of 5 to 40 wt% and off-set preventing agents in an amount of 0.5 to 5 wt%. The composition of the present invention can be used in various forms such as an aqueous solution, an organic solvent solution (e.g., alcohol solution), an aqueous dispersion, a paste, a solid, and the like and coated in the amount hereinbefore described. lt should be noted that the action of the composition of this invention is not dissipated regardless of the kind and the amount of the other components incorporated therein or the form of the composition employed.

The desensitizer composition which can be readily prepared by those skilled in the art as described above is applied on a color developer layer by printing such as relief printing, gravure printing or the like, spraying, or by handwriting e.g., as a solid in the form of a crayon.

The color developers to which the desensitizer com position of the invention is applicable are electron acceptive materials or proton donating solid acids. These color developers are extremely well known in the art. Illustrative specific examples are clay minerals such as acid clay, active clay, attapulgite, etc.; organic acids such as tannic acid, gallic acid, propyl gallate, etc.; acid polymers such as phenol-formaldehyde resins, phenolacetylenc condensation resins, condensates between an organic carboxylic acid having at least one hydroxy group and formaldehyde, etc.; metal salts of aromatic carboxylic acids such as zinc salicylate, tin salicylate, zinc 2-hydroxynaphthoate, Zinc 3,5-di-tert-butylsalicylate, etc.; and mixtures thereof. These color developers are described in US. Pat. Nos. 2,711,375; 2,712,507; 2,730,456; 2,777,780; 2,800,457; 3,293,060; 3,427,180; 3,455,721; 3,466,185; 3,516,845; 3,634,121 and 3,672,935, US. patent applications Ser. Nos. 184,608, filed Sept. 28, 1971; 183,647, filed Sept. 24, 1971; 192,593, filed Oct. 26, 1971 and 192,594, filed Oct. 26, 1971, and the like.

The color developer is applied to asupport such as paper, plastic film-laminated papers, etc. together with a binder such as styrene-butadiene latex, in an amount of l to 90, preferably 5 to 80, parts by weight per 100 parts by weight of the color developer composition calculated on a solids basis.

The color developer composition may contain a binder such as latex, polyvinyl alcohol, maleic anhydride-styrene copolymer, starch and gum arabic. It is to be understood that all binders wel1known as filmforming materials can be used in the invention. The binders can be classified into three groups, i.e., (l) a water soluble or hydrophilic binder, for example, a natural compound such as proteins (e.g., gelatin, gum arabic, colloid albumin, casein), celluloses (e.g., carboxymethyl cellulose, hydroxyethyl cellulose) saccharoses (e.g., agar, sodium alginate, starch, carboxymethyl starch), and a synthetic compound such as polyvinyl alcohol, poly-N-vinylpyrrolidone, polyacrylate, polyacrylamide; (2) a water-dispersible binder, for example, latex such as.styrene-butadiene copolymer latex, styrene-maleic anhydride copolymer latex; and (3) an organic solvent-soluble binder such as nitrocellulose, ethyl cellulose or polyester. These binders can be used in the form of solution or dispersion in a solvent in the invention, and the binder can be varied depending upon the type of the solvent for color developer.

On the other hand, the color formers which generate a color on reaction with the color developer are substantially colorless electron donating or proton accepting organic compounds. Illustrative color formers are triarylmethane compounds, diphenyl-methane compounds, xanthene compounds, thiazine compounds, spiropyran compounds, etc. Specific examples of the triarylmethane compounds include 3,3bis(pdimethylaminophcnyl )-6-dimethylaminophthalide, i.e., crystal violet lactone (hereinafter referred to as CVL"), 3,3-bis(p-dimethylaminophenyl)-phthalide,

3-(p-dimethylaminophenyl)3-( l ,2-dimethylindol-3- yl)phthalide, v 3-(p-dimethylaminophenyl)-3-(2- phenylindol-3-yl )phthalide, 3,3-bis-( 1,2- dimethylindol-3-yl )5-dimethylaminophthalide, 3 ,3- bis( l,2-dimethylindol-3-yl)-6- dimethylaminophthalide, 3,3-bis(9-ethyl-carbazol-3- yl )-5dimethylaminophthalide, 3,3-bis-( 2-phenylindol-3-yl)-S-dimethylaminophthalide, 3-pdimethylaminophenyl-3-( l-methylpyrrol-2-yl)-6- dimethylaminophthalide, and the like. Specific examples of the diphenylmethane compounds include 4,4- bis-dimethylaminobenzhydrinbenzyl ether, N- halophenyl-leuco auramine, N-2,4,5-trichlorophenyl leuco auramine, and the like. Specific examples of the xanthene compounds include rhodamineB- anilinolactam, rhodamine-(p-nitroanilino)lactam, rhodamine B-(p-chloroanilino)lactam, 7-dimethylamino 2-methoxyfluoran, 7-diethyl-a'mino2 methoxyfluoran, 7-diethylamino3-methoxyfluoran, 7-diethylamino-3- chlorofluoran, 7-diethylamino-3-chloro-2-methylfluoran, 7-diethylamino-2,3-dimethylfluoran, 7- diethylamino-( 3-acetylmethylamino)-fluoran, 7- diethylamino-( 3-methylamino )fluoran, 3,7-

diethylaminofluoran, 7-diethylamino-3- (dibenzylamino )fluoran, 7-diethylamino-3-( methylbenzylamino )fluoran 7-diethylamino-3-( chloroethylmethylamino)fluoran, 7diethylamino-3- (diethylamino)-fluoran, and the like. Specific examples of the thiazine compounds include benzoyl leuco methylene blue, p-nitrobenzoyl leuco methylene blue, and the like. Specific examples of the spiro compounds, include 3-methyl-spiro-dinaphthopyran, 3-ethyl-spirodinaphtho -pyran, 3,3-dichloro-spiro-dinaphthopyran, 3-benzylspiro-dinaphthopyran, 3-methyl-naphtho-(3 methoxy-benzo)-spiropyran, 3-propyl-spirodibenzopyran, and the like.

The color formers are applied to a support together with a binder by dissolving the color formers in a synthetic or natural oil such as chlorinated diphenyl, chlorinated terphenyl, alkylated diphenyl, alkylated terphenyl, chlorinated paraffin, chlorinated naphthalene, alkylated naphthalene, kerosene, paraffin and naphthene oil, or by encapsulating it according to the process as described in US. Pat. No. 2,800,457 and the like together with, if desired, additives such as starch particles. In addition, as another embodiment, the color former solution can be coated only on certain specific areas.

As was described hereinbefore, the color former and the color developer can be used in any form suitable for use, such as in a pressure sensitive recording paper, a heat sensitive recording paper or the like.

The present invention will now be described in greater detail by reference to the following non-limiting examples, which serve to demonstrate the excellent ef fects of the present invention. Unless otherwise indicated herein, all parts and percents are by weight.

Additionally, the color developer sheet, the color former sheet and the desensitizing ink, used in the Examples for demonstrating the effects of the desensitizers of the invention, were produced as follows.

PREPARATION OF COLOR DEVELOPER SHEET Parts of sulfuric acidprocessed acid clay was dispersed in 280 parts of water containing 10 parts of 20% sodium hydroxide using a homogenizer. Then, 10 parts of a aqueous solution of methyl vinyl ether-maleic anhydride copolymer sodium salt (1:1 molar ratio, intrinsic viscosity [1 of 0.1 to 0.5) and 37 parts of styrene butadiene latex (53 mol% styrene/47 mol% butadiene; mol wt about 10,000 20,000) were added thereto and applied to a 50 g/m paper in an amount of 10 g/m on a solids basis using air-knife coating followed by drying. Thus, a color developer sheet (A) was obtained.

PREPARATION OF COLOR DEVELOPER SHEET B:

170 Parts of p-phenylphenol, 70 parts of a 37% aqueous solution of formaldehyde and 50 parts of water were condensed at 160C in the presence of 36 wt% concentrated hydrochloric acid as a catalyst. After cooling, a phenol resin powder (degree of polymerization of about 2 to 10 was obtained. To 50 parts of the phenol resin powder was added 10 parts of polyvinyl alcohol (degree of polymerization, about 500; saponification degree, about 88%) and 500 parts of water. The resulting mixture was then ball milled for 10 hours to obtain a coating solution (Coating Solution B).

Coating Solution B was applied to a 50 g/m paper in an amount of 2 g/m on a solids basis, followed by drying. Thus, Color Developer Sheet B was obtained.

PREPARATION OF COLOR DEVELOPER SHEET C 4 Parts of sodium hydroxide was dissolved in 200 parts of water, and 25 parts of 3,S-di-tert-butylsalicylic acid was added thereto with stirring.

Furthermore, a solution prepared by dissolving 7 parts of zinc chloride in 100 parts of water was gradually added thereto with stirring. To this was added 50 parts of a 10% aqueous solution of polyvinyl alcohol (as described above), and the resulting mixture was ball milled for 10 hours to obtain Coating Solution C.

Coating Solution C was applied to a 50 g/m paper in an amount of 2 g/m on a solids basis and dried. Thus, Color Developer Sheet C was obtained.

PREPARATION OF COLOR DEVELOPER SHEET D A mixture of 35 parts of the above described Coating Solution B, 50 parts of the above described Coating Solution C, and parts of agalmatolite clay were ball milled for 10 hours. The thus obtained coating solution was applied to a 50 g/m paper in an amount of 2 g/m on a solids basis, and dried. Thus, Color Developer Sheet D was obtained.

PREPARATION OF COLOR FORMER SHEET A 10 Parts of acid-processed gelatin having an isoelectric point of 8.0 and 10 parts of gum arabic were dis solved in 60 parts of water at 40C, and 0.2 part of sodium dodecylbenzenesulfonate was added thereto as an emulsifier. Then, 50 parts of a color former oil was emulsified therein.

The color former oil used above was prepared by dissolving 2.5% by weight of crystal violet lactone (CVL) and 2.0% by weight of bcnzoyl leucomethylene blue in an oil comprising 4 parts of diisopropylbiphenyl and 1 part of kerosene.

When the average size of the emulsified oil droplets became 8 microns, parts of water at 40C was added.

While continuing the stirring, 210 parts of water at 30C was further added thereto and the pH of the system was adjusted to 4.4 by the addition of a 20% hydrochloric acid solution. While further continuing the stirring, the solution was cooled to 8C and, then, 1.5 parts of 20% glutaraldehyde was added thereto.

Subsequently, 30 parts of a 10% carboxymethyl starch solution (etherification degree, 0.3) was poured thereinto, and the pH of the system was adjusted to 8.5 by adding dropwise a 25% sodium hydroxide solution. Thereafter, the liquid temperature was increased to 30C to obtain microcapsules having hardened capsule walls.

10 Parts of cellulose floc (100 p. in length by 20 p. in diameter on the average) was dispersed therein, and the resulting mixture was applied to a 4 g/m paper in an amount of 6 g/m as solids. Thus, Color Former Sheet A was obtained.

PREPARATION OF COLOR FORMER SHEET B 1% by weight of CVL, 4% by weight of 3- diethylamino-7-diethylaminofluoran, 4% by weight of 3-diethylamino-7-phenylaminofluoran, 3% by weight of 3-diethylamino-7,8-benzofluoran, 0.5% by weight of 3,6-bismethoxyfluoran and 2% by weight of benzoyl leuco methylene blue were dissolved in an oil comprising 1 part of diisopropylnaphthalene, 1 part of diisop'ropylbiphenyl and 2 parts of l-(dimethylphenyl)-lphenylethane to prepare a color former oil.

In a manner analogous to the preparation. of Color Former Sheet A, Color Former Sheet B was obtained using 50 parts of the above-described color former oil.

PREPARATION OF DESEN SITIZING COMPOSITION 10 Parts of titanium oxide was kneaded using a threeroll mill into varnish in which 60 parts of the desensitizer listed in the following table and, as a binder, 30 parts of rosin-modified maleic acid resin were dissolved with heat at C over a period of 30 min. Then, 2 parts of polyethylene glycol (average molecular weightz400) was added thereto to obtain a desensitizing ink composition. The resulting ink composition was printed on each of the above-described color developer sheets in an amount of 2 g/m TESTING METHOD The thus prepared desensitizer was printed on the individual color developer sheet, and color-formation was obtained by applying a load of 600 kg/cm and facing the desensitized areas and the color former sheet toward each other. After 24 hours, the density was measured using a microdensitometer to obtain reflection visual density (Vis. D). The desensitizing effect was rated in terms of the Vis. D.

- C ontmued Ex- Desensitizer Desensitizing Effect (Vis. D) ample Color Former Sheet A Color Former Sheet B Color Color Color Color Color Deve- Dcvc- Deve- Deve- Developcr loper loper loper loper Sheet Sheet Sheet Sheet Sheet A B C D A oxaspirol 5,5 undecanc and 3,4- Epoxy--methylcyclohexylmethyl (equivalent ratio-2:1) 14 Reaction Product 0.01 0.01 0.01 0.01 0.01

between 3,9-bis- (Z-Aminoethyl 2,4,8, l O-tetraoxaspiro-l 5.5 lundecane and a Condensation Product of Epichlorohydrin and Diphenylolpropane* (weight ratio 31l) Com- Without Desen- 1.08 1.05 0.94 1.04 1.05 para sitizertive processing Ex. l Com- C H NH 0.35 0.40 0.45 0.35 0.40 parative Ex. 2 Com- (CH CH O) .H para- C,,,H .,,,-N tive (CH CH O) H Ex. 3

(x+y=l) 0.05 0.10 0.15 0.12 0.11 Com- Urea-formal- 0.24 0.42 0.39 36 0 4 paradehyde Resin tive Prepolymer Ex. 4 Com.- (C H MN 0.33 0.40 0.42 0.39 0.42 parative Ex. 5 Com- HO(CH -CH O) ,H 0.28 0.35 0.37 0.36 0.34 parative Ex. 6

an epoxy equivalent of 182 194 a viscosity of 110 150 poises at C, a specific gravity of 1.167 at 20C, a molecular weight of about 355, an epoxy content of 0.51 0.55 epoxy groups per 100 g of the condensation product and a hydroxy content of 0.06 hydroxy groups per 100 01' the condensation product.

The utility of the compounds of the present invention with reference to specific embodiments thereof, it will is apparent from the above table. That is, the numerical values in the table demonstrate the desensitizing effect. The smaller the numerical value, the greater the desensitizing effect. A difference of not less than 0.5 shows a marked desensitizing effect. The compounds of the present invention provide the desensitizing effect about 100 times that of the desensitizer-free composition (Comparative Example 1) and about 20 times that of the conventional desensitizers (Comparative Examples 2 6). Of the conventional desensitizers, the compound shown in Comparative Example 3 provides better results than the other conventional compounds. However, the desensitizing effect thereof varies depending upon the kind of color former. In contrast, the desensitizers of the invention all exhibit great desensitizing effect regardless of the kind of color formers, and hence they are extremely desirable.

In addition, by utilization of the reaction product of the spiroacetal diamine with a compound having an oxirane group, the desensitizing effect was increased 1.5 to 2 times that obtained with the spiroacetal diamine per se. Also, almost no desensitization fog was formed.

While the invention has been described in detail and be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.

What is claimed is:

l. A developer sheet comprising a color developer layer and a desensitizer composition for desensitizing a color developer capable of reaction with a substantially colorless color former to form a color containing as a desensitizer at least one of a. a spiroacetal diamine compound represented by the following general formula:

O-CH:

irane ring, wherein said desensitizer composition is present in an amount offrom about 0.5 to about 10 g/m on said color developer layer in the areas of said color developer layer containing said desensi tizer composition.

2. The developer sheet of claim 1, wherein said de sensitizer is said spiroacetal diamine compound.

3. The developer sheet of claim 1, wherein said desensitizer is said reaction product of said spiroacetal diamine compound with a compound having at least one oxirane ring.

4. The developer sheet of claim 1, wherein said alkyl group has from 1 to 20 carbon atoms and said alkylene residue has from 1 to 20 carbon atoms.

5. The developer sheet of claim 2, wherein said spiroacetal diamine compound is 3,9- bis(aminomethyl )-2,4,8 l O-tetraoxaspiro 5 ,5 ]undecane, 3,9-bis(2-aminoethyl)-2,4,8,l0-tetraoxaspiro[5,- 5]undecane, 3,9-diethyl-3,9-bis(2-aminoethyl)-2, 4,8,- 10-tetraoxaspiro[5 ,5 ]undecane, 3 ,9bis( 3- aminopropyl)-2,4,8,l-tetraoxaspiro[5,SIundecane,

3 ,9-bis( 4aminobutyl )-2,4,8, 1 O-tetraoxaspiro[5 ,5 undecane, 3,9-bis(S-aminobenzyl)-2,4,8,l0-tetraoxaspiro[ 5,5 ]undecane, or 3,9-bis( l ,1-dimethyl-4- aminobutyl )-2,4,8 l O-tetraoxaspiro[5 ,5 ]undecane.

6. The developer sheet of claim 3, wherein said compound having at least one oxirane ring is an alkyl glycidyl ether, an allyl glycidyl ether, an alkylene oxide, an alicyclic epoxide, an epoxidized vegetable oil fatty acid, or an epoxidized glyceride.

7. The developer sheet of claim 6, wherein the molar ratio of said spiroacetal diamine to said compound having at least one oxirane ring is about 1:1.

8. A developer sheet as claimed in claim 1 comprising a support having thereon a color developer layer and a layer, at least in selected areas of said developer sheet, of said desensitizer composition.

9. The developer sheet of claim 1, wherein said color developer is a clay, an organic acid, an acidic polymer, a metal salt of an aromatic carboxylic acid, or mixtures thereof.

10. A process for desensitizing the coloration generated by a color former'contacting a color developer V which comprises applying to a layer of said color devel- CH O R 1mm, o cn (CH2O wherein R represents a hydrogen atom or an alkyl group, and R and R each represents a straight or branched chain alkylene residue, or

b. the reaction product of said spiroacetal diamine compound with a compound having at least one oxirane ring.

11. The process of claim 10, wherein said desensitizer composition is present in an amount of from about 05 to about 10 g/m on said color developer layer in the areas of said color developer layer containing said layer of said desensitizer composition.

12. The process of claim 10 wherein said alkyl group has from 1 to 20 carbon atoms and said alkylene residue has from 1 to 20 carbon atoms.

13. The process of claim 10 wherein said desensitizer is said spiroacetal diamine compound.

14. The process of claim 13 wherein saidi spiroacetal diamine compound is 3,9-bis(aminomethyl)-2,4,8,10- tetraoxazpiro[5 ,5]undecane, 3 ,9-bis( 2aminoethyl 2,4,8, 1 0-tetrao;.aspiro[5,5 ]undecane, 3,9-diethyl-3 ,9- bis(2-aminoethyl)-2,4,8,lO-tetraoxaspir0[5,5]undecane, 3 ,9-bis( 3 aminopropyl)2.,4,8, l 0-tetraoxaspiro[ 5 5]undecane, 3 ,9-bis (4-aminobutyl)-2,4,8 ,10- tetraoxaspiro[5,5]undecane, 3,9bis(5-aminobenzyl)- 2,4,8, lO-tetraoxaspiro[5,5 ]undecane, or 3,9-bis( 1,1- dimethyl-4-aminobutyl )-2,4,8 l O-tetraoxaspiro[ 5 5]undecane.

15. The process of claim 10 wherein said desensitizer is said reaction product of said spiroacetal diamine compound with a compound having at least one oxirange ring.

16. The process of claim 15 wherein said compound having at least one oxirane ring is an alkyl glycidyl ether, an allyl glycidyl ether, an alkylene oxide, an alicyclic epoxide, an epoxidized vegetable oil fatty acid, or an epoxidized glyceride.

17. The process of claim 16 wherein the molar ratio of said spiroacetal diamine to said compound having at least one oxirane ring is about 1:1.

Claims

1. A DEVELOPER SHEET COMPRISING A COLOR DEVELOPER LAYER AND A DESCENSITIZER COMPOSITION FOR DESENITIZING A COLOR DEVELOPER CAPABLE OF REACTION WITH A SUBSTANTIALLY COLORLESS COLOR FORMULA TO FORM ACOLOR CONTAINING AS A DESCENSITIZER AT LEAST ONE OF A. A SPIROACETAL DIAMINE COMPOUND REPRESENTED BY THE FOLLOWING GENERAL FORMULA:

2. The developer sheet of claim 1, wherein said desensitizer is said spiroacetal diamine compound.

5. The developer sheet of claim 2, wherein said spiroacetal diamine compound is 3,9-bis(aminomethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis(2-aminoethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-diethyl-3,9-bis(2-aminoethyl)-2, 4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis(3-aminopropyl)-2,4,8, 10-tetraoxaspiro(5,5)undecane, 3,9-bis(4-aminobutyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis(5-aminobenzyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, or 3,9-bis(1,1-dimethyl-4-aminobutyl)-2,4,8,10-tetraoxaspiro(5,5)undecane.

10. A PROCESS FOR DESENTIZING THE COLORATION GENERATED BY A COLOR FORMER CONTACTING A COLOR DEVELOPER WHICH COMPRISES APPLYING TO A LAYER OF SAID COLOR DEVELOPER A DESNITIZING COMPOSITION CONTAINING AS A DESENSITIZER AT LEAST ONE OF A. A SPIROACETAL DIAMINE COMPOUND REPRESENTED BY THE FOLLOWING GENERAL FORMULA:

11. The process of claim 10, wherein said desensitizer composition is present in an amount of from about 0.5 to about 10 g/m2 on said color developer layer in the areas of said color developer layer containing said layer of said desensitizer composition.

14. The process of claim 13 wherein saidi spiroacetal diamine compound is 3,9-bis(aminomethyl)-2,4,8,10-tetraoxazpiro(5,5) undecane, 3,9-bis(2-aminoethyl)-2,4,8,10-tetraoxaspiro(5, 5)undecane, 3,9-diethyl-3,9-bis(2-aminoethyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis (4-aminobutyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, 3,9-bis(5-aminobenzyl)-2,4,8,10-tetraoxaspiro(5,5)undecane, or 3,9-bis(1,1-dimethyl-4-amInobutyl)-2,4,8,10-tetraoxaspiro(5,5)undecane.