US3857721A

US3857721A - Sheet containing developer for pressure-sensitive recording

Info

Publication number: US3857721A
Application number: US00232938A
Authority: US
Inventors: T Hayashi
Original assignee: Fuji Photo Film Co Ltd
Current assignee: Fujifilm Holdings Corp
Priority date: 1971-03-09
Filing date: 1972-03-08
Publication date: 1974-12-31
Anticipated expiration: 1991-12-31
Also published as: DE2211434A1; IE37542L; IE37542B1; ES400548A1; GB1346395A; JPS5029364B1

Abstract

A pressure sensitive recording developer sheet comprising a phenolic resin developer coating on a support, the improvement which comprises said phenolic resin developer being a resin which is obtained by modifying with an alkylphenol compound represented by the general formula

WHEREIN R1R2 and R3 which may be the same or different each represents a hydrogen atom or an alkyl group with the proviso that they simultaneously should not be hydrogen atoms, in the condensation of p-phenyl phenol and aldehyde. The coating may also contain microcapsules containing a substantially colorless coupler.

Description

United States Patent [191 Hayashi Dec. 31, 1974 SHEET CONTAINING DEVELOPER FOR PRESSURE-SENSITIVE RECORDING [75] Inventor: Takao Hayashi, Fujimiya, Japan [73] Assignee: Fuji Photo Film Co., Ltd.,

Kanagawa, Japan [22] Filed: Mar. 8, 1972 [21] Appl. No.: 232,938

[30] Foreign Application Priority Data Primary Examiner-William D. Martin- Assistant Examiner-Bernard D. Pianalto Attorney, Agent, or Firm-Sughrue, Rothwell, Mion, Zinn & Macpeak [57] ABSTRACT A pressure sensitive recording developer sheet comprising a phenolic resin developer coating on a support, the improvement which comprises said phenolic resin developer being a resin which is obtained by modifying with an alkylphenol compound represented by the general formula wherein R R and R;, which may be the same or different each represents a hydrogen atom or an alkyl group with the proviso that they simultaneously should not be hydrogen atoms, in the condensation of pphenyl phenol and aldehyde. The coating may also contain microcapsules containing a substantially colorless coupler.

14 Claims, N0 Drawings SHEET CONTAINING DEVELOPER FOR PRESSURE-SENSITIVE RECORDING BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a sheet containing a developer for pressure sensitive recording. More particularly, it relates to an improvement in the phenol resin which is used as a developer for pressure sensitive recording.

2. Description of the Prior Art A pressure sensitive recording sheet utilizes the reaction of an almost colorless organic compound (hereinafter described as the coupler.) and a developing substance which can react with the coupler to form a colored product (hereinafter described as the developer). More particularly, it comprises a sheet coated with mirocapsules containing a solution of a coupler in an organicsolvent (a coupler sheet) and a sheet coated with a developer together with a binder (a developer sheet) and, occasionally a sheet in which a developer is coated on one surface of a support and the microcapsules are coated on the opposite surface (hereinafter described as a pressure sensitive copying sheet). In another embodiment, there is a sheet in which the microcapsules and developer are coated on the same surface of a support.

As couplers, there have been used Malachite Green Lactone, Benzoyl Leuco Methylene Blue, Crystal Violet Lactone, Rhodamine B Lactam, 3-dialkylamino-7- dialkylaminofluorans and 3-methyl-2,2'-spirobi(benzo(f)cumene), and the like.

As substances which react with the coupler to form colored products, there have been used generally clays such as acid clay, active earth, attapulgite, zeolite and bentonite; organic acid compounds such as succinic acid, tannic acid and gallic acid. Recently, it has been newly proposed to use a phenol resin as developer. That is, British Pat. No. 1,065,587 describes the combined use of an oil soluble polymer such as a phenol resin and an acid mineral such as attapulgite as a developer and Japanese Pat. No. 511,757 describes also a polymer such as a phenol resin as a developer. While the phenol resin as a developer has excellent properties in that a water stable colored image on reacting with a coupler such as, for example, Crystal Violet Lactone, is formed it has an insufficient'developing capacity and tends to change readily to yellow in the daylight or on storage in a room disadvantageously.

An object of this invention is an improved pressure sensitive copying sheet.

Another object of this invention is to use an improved phenol resin as a developer for pressure sensitive recording.

SUMMARY OF THE INVENTION wherein R R and R which may be the same or different, each represents a hydrogen atom or an alkyl group with the proviso that they are not simultaneously hydrogen atoms, and an aldehyde.

DETAILED DESCRIPTION OF THE INVENTION the presence ofa catalyst at about to about 200C for several hours.

In the manufacture of the phenol resin of this invention, from about 0.2 to about 2 mols of the phenol represented by the above general formula are suitable for each mol of p-phenyl phenol. While the amount of aldehyde used has little effect on the resin obtained, from about 0.5 to about 2 mols of aldehyde to each mol of phenol i.e., the sum of the p-phenyl phenol and the alkyl phenol, is preferred.

While formaldehyde, acetaldehyde, propionaldehyde and other aldehydes may be used as the aldehyde employed, the reaction takes place with greater difficulty as the number of carbon atoms of the aldehyde increases. Generally, aliphatic monoaldehydes having from I to about 3 carbon atoms are preferred. Formaldehyde is especially preferred.

In general, an acid may be used as catalyst; for example, hydrochloric acid, sulfuric acid, oxalic anhydride and the like are suitable.

The amount of the catalyst used can be varied and in general from about 5 to about 20cc of 37% hydrochloric acid and from about 1 to about 10g for oxalic anhydride can be used. In the use of a solid catalyst, it may be dissolved in a solvent for use.

The resulting modified phenol resin is separated from the liquid phase, dissolved in an organic solvent such as acetone, methyl ethyl ketone, butyl acetate, benzene, toluene, xylene and the like or dispersed in an aqueous binder solution and coated on a paper surface. In another embodiment, the modified phenol resin can be dissolved in an organic solvent, dispersed in aqueous binder solution and coated on a paper surface.

As binders, styrene-butadiene latex, maleic anhydride-styrene copolymer, polyvinyl alcohol, starch, casein, ethyl cellulose, styrenebutadiene copolymer, polyvinyl acetate, polyvinylidene chloride, vinyl chloridevinylidene chloride copolymer and the like are suitable.

The amount of binder generally used ranges from about 5 to about 30 parts by weight per 100 parts by weight of the modified phenol resin.

The developer layer of this invention may contain clay minerals having a developing capacity, e.g., Japanese acid clay or active clay or an inorganic pigment having an adsorption capability or a mixture thereof.

In comparision with developer sheets using previous phenol resins, the developer sheet using the phenol resin obtained in this invention has a strong developing invention capacity with respect to the coupler and excellent properties in that it changes to yellow in the daylight or on storage in a room with difficulty.

The phenol resins'described in the above referred British Pat. No. 1,065,587 and Japanese Pat. No. 511,757 were obtained by the condensation of a single phenol compound with an aldehyde. As discussed above, however, the developer sheet for pressure sensitive copying using this phenol resin of a single phenol compound does not have sufficient developing capacity and tends to be discolored into yellow in the daylight or on storage in a room. i v I The phenolresin according to this invention is obtained by the condensation of at least two phenol com. pounds with an aldehyde. The developer sheet for pressure sensitive copying using the phenol resin obtained by the method as described above employing at least two phenol compounds has'excellent properties in that it has a strong developing capacity and changes with difficulty into yellow in the daylight or on storage in a room. 4

When the relation between the chemical composition of the phenol resin of this invention and developing capacity and yellow discoloration resistance of the developer sheet for pressure sensitive copying based on the fact as mentioned above, it is obvious that a useful effect is obtained by the use of the phenol resin prepared sheet:

A microcapsul econtaining coupler wasprepare'd, for

example, according to disclosure in US. Pat. No.

2,800,457 andan example thereof is described asfollows:

10 parts of pigle'ather acid-treatedgelatin and 10 parts-of gum a'rabic are dissolved in 400 parts of water, 02 part of Turkey red oil is added as an emulsifier and 40 parts of oil coupler are emulsified therein. The coupler oil contains 2% of Crystal Violet Lactone dissolved in an oil consisting of 4 parts of diphenyl chloride and 1 part of kerosene.

When the size of the oil droplets is on an average of 5 u, the em ulsification is ceased. Waterat 40C is added thereto to make 900 parts total and the. stirring is continued, during which time the liquid temperature should fall below 40C. 10% acetic acid is then'added to adjust the pH-value of liquid to 4.0 4.."2 resulting in coacervatiomAfter stirring for a 20 minute period, it

is cooled by ice water to gel the coacervate film depo's- 30C, coated in an amount of 6g(solid)/m on a paper of 40g/m and dried.

' 4 Other coupler containing sheets using microcapsules containing Malachite Green Lactone, Benzoyl Leuco Methylene Blue, Rhodamine B Lactum, 3-

dialkylamino-7-dialkylamino-fluorans and 3-methyl- 2,2-spiro (benzo (f) cumene) or mixtures thereof as the couplers were prepared in the same manner as described above for the Crystal Violet Lactone.

EXAMPLE 1 g of p-phenyl phenol, 75g of p-t-butyl phenol. g of aqueous 37% formaldehyde, 10 ml'of conc. hydrochloric acid (37%) and-50ml of water were placed in a kettle to prepare the-resin and heated at C for 10 hrs. The resulting resin was cooledand then ground. 10g of the resulting resin were dissolved in 40 ml of acetone, coated in an amount of 2g/m and dried.

. CONTROL 1 g of p-phenyl phenol, 100g of aqueous 37% formaldehyde, 10 ml of cone hydrochloric acid (37% and 50cc of water were placed in akettle for to prepare a resin and heated at 140C for 10 hrs. The resulting resin was cooled and then ground. 10g of the resulting resin were dissolved in 40 ml of acetone, coated in an amountof Zg/m on a paper of 40 g/m and dried.

EXAMPLE 2 85g of p-phenyl phenol, 55g of p-nonyl phenol, 50g of aqueous 37% formaldehyde, l0g'of oxalic anhydride and 5.0 mlof water were placed in a kettle to prepare the resin and heated at C for 5 hrs. The resulting resin was cooled and then ground. 10g of the resulting resin'were dissolved in;4 0 ml of benzene, coated inan amount of 2 g/m on apaper of 40 g/m and dried.

I CONTROL 2 -127.5g of pphenyl phenol,"50g of aqueous 37 7gj formaldehyde, 10g oxalic anhydride and 50 ml of water were placed in a kettleto prepare the resin and heated at 180C for 5 hrs. Theresulting resin was cooled and then ground. IOgjof the resulting resin were dissolved .in 40ml of benzene; coated in an amount of 2 gm: on

and dried.

EXAMPLE 3 85g of p-phenyl phenol; 91 .5g' of3,4 -xy lenol, 50g of aqueous 37%.formaldehyde, 10 ml of cone. hydrochloa paper of 40 g/m' ric acid (37%), lgof oxalic anhydride and 50 ml of water were placed in a kettle to prepare the resin and heated at 160C for 8 hrs. The resulting resin was cooled and then ground. 10g of the resulting resin were dissolved in 40 ml of methyl ethyl ketone, coated in an amount of 'g/m? on a paper of 40 g/m and dried.

CONTROL 3 212.5g of p-phenyl phenol. 50g of-aqueous 37% formaldehyde,'l0,m l of cone. hydrochloric acid (37%). 1g

of oxalic anhydride and 50 ml of water were placed in a kettle to prepare the resin and heated at 160C for 8 hrs. 10g of the resulting resin were dissolved in 40 ml of methyl ethyl ketone, coated in an amount of 2'g/m on a paper of 40 g/m and dried. in order toicompare the samples prepared as described above,the following trols l, 2 and 3 and developed by applying a load pressure of 600 kg/cm After standing for 1 hour in the dark, the spectral absorption curve in the wave length range of 700 400 mu was measured and the develop ing capacity of each developer sheets was examined using the density (D,) at the maximum adsorption (610 mu).

2. After exposing each developer sheet of Examples l, 2 and 3 and Controls 1,2 and 3 to the sun for 5 hrs, the whiteness of each sheet was determined using a Hunter Brightness Meter and the yellowing tendency of developer sheet was measured based on the whiteness value.

The results of (1) and (2) are shown in Table I.

Table l whiteness after Sun Exposure for 5 hrs.

Developing Capacity (D,) for Crystal Violet Lactone Example l 0.934

57.4 Control I 0.713 41.8

Example 2 0.877 52.5 Control 2 0.640 373 Example 3 0.878 55.7 Control 3 0.795 40.6

The same effect was obtained for the other couplers described herein before.

EXAMPLE 4 EXAMPLE 5 The resins obtained as in Examples 2 and 3 are coated in the same manner as described in Example 4 to obtain a single-sheet type pressure-sensitive recording paper. While the above invention has been described in detail and with reference to certain embodi ments thereof, it will be recognized that modifications and variations can be made therein without departing from the spirit and scope thereof.

What is claimed is:

1. In a pressure sensitive recording developer sheet comprising a phenolic resin developer coated on a support, the improvement which comprises said phenolic resin developer being the condensation product of pphenyl phenol and at least one alkyl phenol represented by the general formula R2 OH wherein R R and R which may be the same or different, each represents a hydrogen atom or an alkyl group, said alkyl group containing from 1 to 12 carbon atoms, with the proviso that R R and R are not simultaneously a hydrogen atom, with an aldehyde. wherein said alkyl phenol is present in said condensation product at a level of from about 0.2 to about 2 moles of said alkyl phenol per mole of p-phenyl phenol and said aldehyde is present at a level offrom about 0.5 to about 2.0 moles of aldehyde per total moles of phenol.

2. The sheet of claim 1 wherein said alkyl phenol is selected from the group consisting of p-cresol, p-ethyl phenol, p-t-butyl phenol, p-t-pentyl phenol, p-nonyl phenol, p-dodecyl phenol, p-octyl phenol, 3,4-xylenol, and thymol.

3. The sheet of claim 1, wherein said aldehyde is selected from the group consisting offormaldehyde, acetaldehyde and propionaldehyde.

4. The sheet of claim 3, wherein said aldehyde is formaldehyde.

5. The sheet of claim I, wherein said phenolic resin developer is incorporatedinto a binder coated on said support.

6. The sheet of claim 5, wherein said binder is selected from the group consisting of styrene-butadiene latex, maleic anhydride-styrene copolymer. polyvinyl alcohol, starch, casein, polyvinylidene chloride and vinyl chloride-vinylidene chloride copolymer.

7. The sheet of claim 5 wherein said binder is present at a level of from about 5 to about 30 parts by weight for each parts by weight of said phenolic resin.

8. In a pressure sensitive recording sheet comprising a support having coated thereon microcapsules containing a substantially colorless coupler and a phenolic resin developer, said coupler being one which forms a color upon contact with said phenolic resin developer, the improvement which comprises said phenolic resin developer being the condensation product of p-phenyl phenol and at least one alkyl phenol represented by the general formula where R,, R and R which may be the same or different, each represents a hydrogen atom or an alkyl group having 1 to [2 carbon atoms, with the proviso that R,, R and R are not simultaneously a hydrogen atom, with an aldehyde, wherein said alkyl phenol is present in said condensation product at a level of from about 0.2 to about 2 moles of said alkyl phenol per mole of p-phenyl phenol and said aldehyde is present at a level of from about 0.5 to about 2.0 moles of aldehyde per total moles of phenol.

9. The sheet of claim 8 wherein said alkyl phenol is selected from the group consisting of p-cresol, p-ethyl phenol, p-t-butyl phenol, p-t-pentyl phenol. p-nonyl phenol, p-dodecyl phenol, p-octyl phenol, 3,4-xylenol, and thymol.

10. The sheet of claim 8, wherein said aldehyde is selected from the group consisting of formaldehyde, acetaldehyde and propionaldehyde.

11. The sheet of claim 10, wherein said aldehyde is formaldehyde.

12. The sheet of claim 8, wherein said phenolic resin developer is incorporated into a binder coated on said support.

13. The sheet of claim 12, wherein said binder is selected from group consisting of styrene-butadiene latex, maleic anhydride-styrene copolymer, polyvinyl alcohol, starch, casein, polyvinylidene chloride and vinyl chloride-vinylidene chloride copolymer.

14. The sheet of claim 12 wherein said binder is present at a level of from about 5 to about 30 parts by weight for each 100 parts by weight of said phenolic

Claims

1. IN A PRESSURE SENSITIVE RECORDING DEVELOPER SHEET COMPRISING A PHENOLIC RESIN DEVELOPER COATED ON A SUPPORT, THE IMPROVEMENT WHICH COMPRISES SAID PHENOLIC RESIN DEVELOPER BEING THE CONDENSATION PRODUCT OF P-PHENYL PHENOL AND AT LEAST ONE ALKYL PHENOL REPRESENTED BY THE GENERAL FORMULA

3. The sheet of claim 1, wherein said aldehyde is selected from the group consisting of formaldehyde, acetaldehyde and propionaldehyde.

4. The sheet of claim 3, wherein said aldehyde is formaldehyde.

5. The sheet of claim 1, wherein said phenolic resin developer is incorporated into a binder coated on said support.

6. The sheet of claim 5, wherein said binder is selected from the group consisting of styrene-butadiene latex, maleic anhydride-styrene copolymer, polyvinyl alcohol, starch, casein, polyvinylidene chloride and vinyl chloride-vinylidene chloride copolymer.

7. The sheet of claim 5 wherein said binder is present at a level of from about 5 to about 30 parts by weight for each 100 parts by weight of said phenolic resin.

8. In a pressure sensitive recording sheet comprising a support having coated thereon microcapsules containing a substantially colorless coupler and a phenolic resin developer, said coupler being one which forms a color upon contact with said phenolic resin developer, the improvement which comprises said phenolic resin developer being the condensation product of p-phenyl phenol and at least one alkyl phenol represented by the general formula

9. The sheet of claim 8 wherein said alkyl phenol is selected from the group consisting of p-cresol, p-ethyl phenol, p-t-butyl phenol, p-t-pentyl phenol, p-nonyl phenol, p-dodecyl phenol, p-octyl phenol, 3,4-xylenol, and thymol.

11. THE SHEET OF CLAIM 10, WHEREIN SAID ALDEHYDE IS FORMALDEHYDE.

14. The sheet of claim 12 wherein said binder is present at a level of from about 5 to about 30 parts by weight for each 100 parts by weight of said phenolic resin.