JP2897641B2 - Crystal modification of 4,4'-bis {N '-(p-toluenesulfonyl) ureido} diphenylmethane - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a 4,4'-bis {N '
The present invention relates to a novel crystal modification of-(p-toluenesulfonyl) ureido diphenylmethane (hereinafter abbreviated as B-TUM).

[0002]

2. Description of the Related Art In general, a heat-sensitive recording material is formed on a support such as paper, synthetic paper, plastic film or the like by a color-forming substance such as an electron-donating leuco dye and an organic acidic substance such as an electron-accepting phenolic compound. A heat-sensitive coloring layer mainly composed of a color-developing substance is provided, and these can be reacted by thermal energy to obtain a recorded image. Such a thermal recording medium is disclosed in JP-B-43-4160 and JP-B-45-14.
No. 039 and JP-A-48-27736, etc., and are widely used.

[0003] The thermal recording medium has a compact, inexpensive recording device and is easy to maintain. Therefore, the output of an electronic computer, a facsimile, an automatic ticket vending machine, a printer of a scientific measuring instrument, a printer of a CRT medical measurement, etc. Widely used in However, in a conventional so-called dye-type heat-sensitive recording material in which a heat-sensitive coloring layer containing a color-forming dye substance, a color-developing substance and a binder as an active ingredient is coated on a support, the coloring reaction is reversible. For this reason, it is known that a color image loses its color over time. This decolorization is accelerated by exposure to light, high humidity, and high temperature, and is further promoted by prolonged standing in water, contact with oils such as salad oil, and plasticizers. It will be erased.

[0004] When the conventionally known B-TUM is used as a color-developing substance, the above-mentioned problems of the prior art can be solved. In particular, there is no loss of a once-colored image, excellent storage stability of a recorded image, and excellent recording stability. A thermosensitive recording medium having high sensitivity can be manufactured. More specifically, a heat-sensitive recording material using B-TUM as a color developing material has good long-term storage properties of a recorded image, and at the same time, has excellent water resistance, oil resistance, and plasticizer resistance of the recorded image. For example, it can be used not only as a thermal recording type ticket for automatic ticket vending machines, but also for coupons and commuter passes that require preservation, and plastics that cannot avoid contact with plasticizers and oils and fats. It is suitable as a label for a bar code system for POS to be attached to the packaging surface of a food packaged with a vinyl chloride film. Furthermore, long-term storage facsimile and word processing papers that require high sensitivity,
It is also effective as CRT image printer paper.

As described above, B-TUM has the property of significantly improving the storage stability of a recorded image, but it has been found that the physical properties of the obtained compound differ depending on the synthesis method and the like. . This is considered to be a polymorphism of the crystal, but a clear characterization is required for stable production of the product. In addition, it is important to actively utilize the difference in physical properties due to these crystals to create a technical base for producing a thermosensitive recording medium having characteristics.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel crystal modification of B-TUM which is useful as a color developing material for a thermosensitive recording medium.

[0007]

According to the present invention, the 4,4'-
The first crystal modification of bis {N '-(p-toluenesulfonyl) ureido} diphenylmethane has the following structural formula (I):

Embedded image And in its X-ray diffraction diagram, Cu
-The diffraction angle (2θ) by Kα ray is 10.2 °, 14.1
5. Show strong peaks at 19.1 ° and 19.1 °, and 6.
It has a crystal form (B) showing intermediate intensity peaks at 6, 8.4, 11.1 and 15.6 degrees.

The 4,4'-bis {N '-(p) according to the present invention
The second crystalline modification of -toluenesulfonyl) ureidodiphenylmethane has the following structural formula (I):

Embedded image And in its X-ray diffraction diagram, Cu-
The diffraction angle (2θ) by Kα ray is 6.0 ° and 2
It has a crystalline form (C) which shows a strong peak at 1.2 ° and intermediate peaks at 15.8 ° and 19.0 °.

The 4,4'-bis {N '-(p) according to the present invention
The third crystalline modification of -toluenesulfonyl) ureidodiphenylmethane has the following structural formula (I):

Embedded image And in the amorphous state (D).

[0010]

B-TUM has already been disclosed in Japanese Patent Application Laid-Open No. 5-147357 as being useful as a color developer.
A strong peak at a diffraction angle (2θ) of 10.3 ° due to -Kα radiation, and 7.2 °, 13.2 °, and 1
It is a crystal form showing a peak of intermediate intensity at 5.6 ° (hereinafter, referred to as crystal form A), which has extremely excellent storage stability of recorded images. However, the present inventors have conducted intensive studies on the crystal form and the color development characteristics of the thermosensitive recording medium obtained by using the B-TUM. Also found that there were three types of crystal modifications. That is, in addition to the crystal form A, in X-ray diffraction, the diffraction angles (2θ) by Cu-Kα rays are 10.2 °, 14.1 °, and 19.
It shows a strong peak at 1 ° and 6.6 °, 8.
A crystalline form (referred to as crystalline form B) showing intermediate intensity peaks at 4 °, 11.1 ° and 15.6 °, strong peaks at 6.0 ° and 21.2 °, and 15. 8
At 3 ° and 19.0 °, three types of crystal modifications were observed: a crystal form showing a peak of intermediate intensity (denoted as crystal form C) and an amorphous state (denoted as amorphous state D) without taking any crystal form. Was issued.

When B-TUM is used for a thermosensitive recording medium in any of the crystalline form B, crystalline form C, and amorphous state D, its color image shows very excellent storage stability as in crystalline form A. Is shown. Furthermore, as compared with the crystalline form A, the thermosensitive recording medium using the crystalline form B B-TUM has particularly high whiteness and good sensitivity, and the crystalline form C or the amorphous state D
-A thermosensitive recording medium using TUM has a feature of being particularly high in sensitivity.

The present inventors have also found that there are several synthetic methods for B-TUM, and that there is a strong correlation between the synthetic methods and the obtained crystal forms. For example,
B-TUM obtained by adding p-toluenesulfonyl isocyanate to a solution of 4,4'-diaminodiphenylmethane in acetonitrile and reacting it takes the form of crystalline form A. On the other hand, the product obtained by dissolving 4,4'-diaminodiphenylmethane in a large amount of ethyl acetate, adding p-toluenesulfonyl isocyanate thereto, and reacting the resultant has the crystal form B. Also, diisocyanic acid 4,4 '
-Diphenylmethane is dissolved in acetone and p
The one obtained by adding toluenesulfonamide has the crystalline form C; Further, each of the B-TUM crystal forms A, B, and C is heated to a temperature equal to or higher than its melting point and melted, and then cooled to take an amorphous state D.

Next, the crystal modification of B-TUM will be described with reference to an X-ray diffraction diagram. 1 to 4 show powder X by Cu-Kα ray.
FIG. 3 is an X-ray diffraction diagram in which a diffraction angle (2θ) is recorded using a scintillation counter in a line diffraction method.

FIG. 1 is an X-ray diffraction pattern of crystal form A, which shows a strong peak at a diffraction angle (2θ) of 10.3 °;
Mid intensity peaks are shown at 2 °, 13.2 °, and 15.6 °.

FIG. 2 is an X-ray diffraction pattern of crystal form B, showing diffraction angles (2θ) of 10.2 °, 14.1 °, and 19.1 °.
° shows a strong peak and 6.6 °, 8.4 °, 1
The peaks of intermediate intensity are shown at 1.1 ° and 15.6 °.

FIG. 3 is an X-ray diffraction diagram of crystal form C.
Strong peaks at 0 ° and 21.2 ° and 1
It shows peaks of intermediate intensity at 5.8 ° and 19.0 °.

FIG. 4 is an X-ray diffraction diagram of the amorphous state D, showing a halo state seen in the amorphous state. Note that an error of about ± 0.2 ° is allowed in displaying the diffraction angle.

These X-ray diffraction diagrams show the crystal modifications of B-TUM and clearly show the differences between the crystal modifications. The B-TUM of each crystal modification is usually in the form of a white powder, and it is difficult to identify which crystal modification by visual inspection, but perform X-ray diffraction measurement on the obtained B-TUM. Can be distinguished by

Further, the melting point of B-TUM varies depending on each crystal modification. The melting point of crystal form A is 160 degrees, the melting point of crystal form B is 120 degrees, and the melting point of crystal form C is 13 degrees.
Three degrees. B-TUM in the amorphous state D does not show a clear melting point, but when observed by a melting point microscope,
It is recognized that melting starts at around 120 degrees. Identification of these B-TUM crystal modifications can also be performed by measuring their melting points.

[0020]

The present invention will be described in detail with reference to the following examples. Unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

Example 1 4,4'-bis {N '-(p-
Toluenesulfonyl) ureido diphenylmethane crystal
In a three-necked flask equipped with a synthetic dropping funnel of form B and a thermometer,
9.9 g of 4,4'-diaminodiphenylmethane (0.0
5 mol) was dissolved in 120 ml of ethyl acetate. While vigorously stirring the solution, p-toluenesulfonyl isocyanate was added to the solution from a dropping funnel.
g (0.1 × 1.025 mol) was added dropwise. An exothermic reaction occurred simultaneously with the start of the dropping, and a white solid precipitated. The resulting reaction mixture was stirred for an additional hour and filtered to 28.1 g.
Was obtained as white crystals. An X-ray diffractometer (trade name: Geigerflex®) manufactured by Rigaku Denki Co., Ltd.
(INT-2200). When the diffraction angle (2θ) was recorded by a powder X-ray diffraction method using Cu-Kα radiation using a scintillation counter, an X-ray diffraction pattern as shown in FIG. 2 was obtained, and its melting point was 120 ° C. .

Example 2 4,4'-bis {N '-(p-
Toluenesulfonyl) ureido diphenylmethane crystal
In a three-neck flask equipped with a synthetic dropping funnel of form C and a thermometer,
6.8 g (0.04 mol) of p-toluenesulfonamide were added and dissolved in 30 ml of acetone. While stirring the solution, add 1N sodium hydroxide solution 40
and 4,4'-diphenylmethane diisocyanate 5.0 dissolved in 20 ml of acetone.
g (0.02 mol) was added dropwise. Simultaneously with the start of the dropwise addition, cloudiness occurred, and a white solid precipitated. The mixture was stirred for an additional hour, neutralized with 5% aqueous hydrochloric acid, filtered and filtered.
0.6 g of a white powdery material was obtained. This white powder gives an X-ray diffraction pattern as shown in FIG.
3 ° C.

Example 3 4,4'-bis {N '-(p-
Toluenesulfonyl) ureidodiphenylmethaneamo
Synthesis of Rufus State D According to the same synthesis method as in Example 1, 4,4'-bis {N'-
White crystals of (p-toluenesulfonyl) ureido diphenylmethane were obtained. Thereafter, when this was heated at 140 ° C., melting occurred. Then, when it was naturally cooled at room temperature, solidification occurred again. The resulting material is X as shown in FIG.
A line diffraction diagram was given, and there was no clear melting point. According to observation with a melting point microscope, melting was observed at around 120 ° C.

Thermal recording paper preparation example 1 A thermal recording paper was prepared by the following operation. (1) Preparation of pigment-coated paper calcined clay (trademark: Ansilex, ENGEL HAR)
To a dispersion obtained by dispersing 85 parts of D (produced by Company D) in 320 parts of water, 40 parts of a styrene / butadiene copolymer emulsion (50% solid content) and 50 parts of a 10% aqueous starch oxide solution were mixed. A coating solution was prepared. 48 g / m ^{2 of} this coating solution
Was coated on the base paper so that the coating amount after drying was 7.0 g / m ² , thereby producing a pigment-coated paper.

[0025] (2) Preparation of Dispersion Liquid Ingredients Amount of A (parts) 3- (N-isopentyl -N- ethylamino) -6-methyl-7-anilinofluoran 20 polyvinyl alcohol 10% solution 10 Water 70 The above Using a sand grinder, the composition has an average particle size of 1
It was pulverized until it became not more than μm.

[0026] (3) Preparation Ingredients Amount of Dispersion B (parts) of 4,4'-bis {N '- (p-toluenesulfonyl) ureido} diphenylmethane (synthesized in Example 1, X-ray diffraction in FIG. 2 20) Polyvinyl alcohol 10% liquid 10 Water 70 The above composition was subjected to a sand grinder with an average particle size of 1
It was pulverized until it became not more than μm.

[0027] (4) Preparation Ingredients Amount of Dispersion C (parts) diphenyl sulfone 20 polyvinyl alcohol 10% solution 10 Water 70 The composition using a sand grinder to an average particle size of 1
It was pulverized until it became not more than μm.

(5) Formation of thermosensitive coloring layer To 60 parts of solution A, 120 parts of solution B and 120 parts of solution C, 26 parts of calcium carbonate pigment, 12 parts of 25% zinc stearate dispersion and 30% paraffin dispersion 10 parts and 80 parts of a 10% aqueous solution of polyvinyl alcohol were mixed and stirred to obtain a coating liquid. This coating solution was applied and dried on the pigment-coated surface of the pigment-undercoated paper so that the coating amount after drying was 5.0 g / m ² to form a thermosensitive coloring layer, thereby producing a thermosensitive recording paper.

[0029] (6) a heat-sensitive recording paper obtained in the manner of the calendar processing the processed by a super calendar, smoothness of the surface 800-120
0 seconds.

(7) Test A sample of the heat-sensitive recording paper thus obtained was applied with a dynamic color tester modified from a commercially available heat-sensitive facsimile machine manufactured by Hitachi, Ltd. to apply 0.39 mj / dot and 0.49 mj / dot. A color image was formed with energy. The color density was measured with a Macbeth reflection densitometer RD-914, and this was used as a value representative of the recording sensitivity. Further, the whiteness of the sample was measured with a Hunter whiteness meter.

Also, within 30 minutes after color development, salad oil and dioctyl phthalate (DOP: representative plasticizer) were added to a sample colored with an applied energy of 0.49 mj / dot.
Was applied and left at room temperature for 30 minutes, excess oil or plasticizer was wiped off, the residual image density was measured with a Macbeth reflection densitometer, and the image storage rate was calculated according to the following equation. Image preservation ratio (%) = (residual image density) / color density before coating × 100 The test results are shown in Table 1.

Example 2 of Preparation of Thermal Recording Paper The same operation as in Preparation Example 1 of thermal recording paper was performed. However, when preparing the dispersion B, 4,4′-bis {N ′-(p-
As the toluenesulfonyl) ureido diphenylmethane, the one of crystal form C synthesized in Example 2 and giving the X-ray diffraction pattern of FIG. 3 was used. Table 1 shows the test results.

Preparation Example 3 of Thermal Recording Paper The same operation as in Preparation Example 1 of thermal recording paper was performed. However, when preparing the dispersion B, 4,4′-bis {N ′-(p-
As toluenesulfonyl) ureido diphenylmethane, the one in the amorphous state D synthesized in Example 3 and giving the X-ray diffraction diagram of FIG. 4 was used. Table 1 shows the test results.

Preparation of Thermosensitive Recording Paper Comparative Example 1 The same operation as in Preparation of Thermosensitive Recording Paper 1 was performed. However, when preparing the dispersion B, 4,4′-bis {N ′-(p-
As the toluenesulfonyl) ureido diphenylmethane, the one having the crystal form A giving the X-ray diffraction pattern of FIG. 1 was used. Table 1 shows the test results.

Preparation of Thermosensitive Recording Paper Comparative Example 2 The same operation as in Production Example 1 of thermosensitive recording paper was performed. However, when preparing the dispersion B, 4,4′-bis {N ′-(p-
Instead of toluenesulfonyl) ureidodiphenylmethane, 2,2-bis (4-hydroxyphenyl) propane (that is, bisphenol A) was used. Table 1 shows the test results.

[0036]

[Table 1]

As is clear from Table 1, the color images obtained by using the crystal modifications B, C and D of 4,4'-bis {N '-(p-toluenesulfonyl) ureido} diphenylmethane of the present invention All were excellent in oil resistance and plasticizer resistance. Note that, compared to the crystal form A, the crystal form B
In particular, when the thermal recording paper obtained is used, the whiteness of the obtained thermal recording paper is high and the sensitivity is good.
It was confirmed that the heat-sensitive recording layer obtained also when used was characterized by exhibiting high sensitivity.

[0038]

According to the present invention, the 4,4'-bis {N '-(p-
Toluenesulfonyl) ureido diphenylmethane 3
Each of the novel crystal modifications forms a color-developed image having extremely excellent storage stability. The heat-sensitive recording materials manufactured using the crystal modifications B, C, and D are:
In particular, they exhibit characteristic properties such as excellent whiteness and sensitivity, and are extremely useful in practice.

[Brief description of the drawings]

FIG. 1 is an X-ray diffraction diagram of known crystal modification A of B-TUM.

FIG. 2 shows the X-form of the crystalline modification B of the present invention of B-TUM.
Line diffraction diagram.

FIG. 3 shows the X-form of the crystalline modification C of the present invention of B-TUM.
Line diffraction diagram.

FIG. 4 is an X-ray diffraction diagram of a crystalline modification (amorphous state) D of B-TUM according to the present invention.

[Explanation of symbols]

 2θ: diffraction angle by Cu-Kα ray

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C07C 311/60 B41M 5/30 CA (STN) REGISTRY (STN)

Claims (3)

(57) [Claims] 1. The following structural formula (I): And in its X-ray diffraction diagram, Cu
-The diffraction angle (2θ) by Kα ray is 10.2 °, 14.1
5. Show strong peaks at 19.1 ° and 19.1 °, and 6.
4,4'-having crystalline form (B) with intermediate intensity peaks at 6 °, 8.4 °, 11.1 ° and 15.6 °
Crystal modification of bis {N '-(p-toluenesulfonyl) ureido} diphenylmethane. 2. The following structural formula (I): And in its X-ray diffraction diagram, Cu-
The diffraction angle (2θ) by Kα ray is 6.0 ° and 2
4,4'-bis {N '-(p-toluene) having a crystal form (C) showing a strong peak at 1.2 ° and intermediate peaks at 15.8 ° and 19.0 ° Crystal modification of (sulfonyl) ureidodiphenylmethane. 3. The following structural formula (I): And a crystalline modification of 4,4'-bis {N '-(p-toluenesulfonyl) ureido} diphenylmethane in the amorphous state (D).