JPS58199192A - Binder for heat sensitive recording - Google Patents

Abstract

PURPOSE:To provide the binder for heat sensitive recording excellent in thermal characteristics and strength, comprising a compound containing an atomic group -(NHCO)- in the molecule thereof. CONSTITUTION:A compound having an isocyanate group (e.g., diisocyanate or triisocyanate) and a compound having active hydrogen (e.g., alkyl alcohol or aryl alcohol) are reacted to obtain a compound containing an atomic group -(NHCO)- in the molecule thereof. This compound has the atomic group -(NHCO)- in the molecule thereof, for example, urea bond, urethane bond, thiourethane bond, carbamic-carboxylic anhydride bond and acid-amide bond. The titled binder for heat sensitive recording is constituted from those aforementioned compounds.

Description

[Detailed Description of the Invention] The present invention relates to a heat-sensitive recording binder with excellent thermal properties and strength = heat-sensitive recording method, particularly a system using a substance that is in a solid phase at room temperature and turns into a liquid phase when heated. For example,
An opaque layer in which wax and metal soap are dispersed in a resin is provided on the colored support-F.1. Wow.

1) Fusible colored wax, one that uses an intermediate sheet coated with wax and melts and transfers it onto the image-receiving sheet using heat, or porous paper. There is a known method in which a fusible wax is applied to the material and the material is heated to remove the melted wax and allow the ink to pass through (edited by Masanobu Wada, Insho Kogaku I, Kyoritsu Shuppan).

In general, the various properties required of a binder for heat-sensitive recording include the ability to prevent dark reactions before use, resistance to abrasion, bending, heat, cold, and chemicals, and melting properties during heated printing. , prevention of unnecessary color development due to heat transfer to non-image areas, etc. Currently, the only product that has these properties to a certain extent is rose finwa.

Waxes such as wax, montan wax, seresin wax, castor wax, and stearic acid.

Stearic acid and its derivatives such as stearic acid amide, stearic acid metal salts, higher fatty acid amides, etc. are used.

As the heat-melting layer, wax such as natural wax or synthetic wax is usually used.

Although these waxes appear to be a single material, they are actually made up of a mixture of compounds with different molecular weights.
Therefore, the temperature range from when it starts to melt by heating until it is completed is wide, from 5 to 10 degrees Celsius, and depending on the unevenness of the heat applied during recording, the melting may not be sufficient and recording may not be possible. When excessive heat is applied, heat conduction causes melting of parts that should not be melted in the vicinity of the nine locations, which tends to cause K smudges in the print.

That is, if a binder with a wide melting temperature range is used, it is difficult to record clear contoured characters or shapes. In addition to the above-mentioned disadvantages, when using natural wax, there is also the disadvantage that its composition varies depending on the place of production and the weather conditions during growth, making it difficult to produce products of constant quality.

In view of the above-mentioned conventional drawbacks, the present inventors conducted research and found that when a reaction product of a compound having an incyanate group and a compound having active hydrogen is used, the product is solid at room temperature and has a clear structure. It was discovered that it has a melting point in a narrow temperature range, and has sufficient strength and various resistances in the solid state.
This has led to the present invention. That is, the present invention relates to a heat-sensitive recording binder comprising a compound containing an atomic group of -(NHCO+) in the molecule.

The present invention will be explained in detail below.

The binder of the present invention is a compound containing an atomic group ÷NHCO+ in its molecule, such as a urea bond, a urethane bond, a thiourethane bond, a carbamate carboxylic acid anhydride bond, an acid amide bond, etc.

It includes compounds having the atomic group +NHCO+ and represented by the following general formula.

iL (NHCO) R' R(NHCO) OR' or) L(NHC'0)8R/
R (NHCO) 0ORI B (NHCO) NH.

R (NHCO) NHR’ R (NHCO) Naki R(NHCO)　oNR'.

R(NHCO) oNcaI2 R (NHCO) NHOH R (NHCO) N (COR')2 R (NHCO) NHR’80iNa R (NHCO) NH80, person r R(NHCO)(NHCO)NHK’ R(NHCO)(NHCO)NH.

R (NHCO) (NHCO) Nn'.

R(NHCO)NHNH(CONH)R'R(NHCO
)CI R(NHCO) Rr R(NHCO)CN R(NHCO)80sNm 1'L (NHCO)CH(COOR').

FL (NHCO)C)i(COCH,)COOR' or above, this is an example of a case where the compound has one atomic group 4 NHCO+, but the above urea bond, urethane bond, thiourethane bond, carbamic acid carboxylic acid anhydride It may contain two or more bonds, acid amide bonds, etc.

It is an alkyl group having about 1 to 22 base primes such as thyl, amyl, hexyl, octyl, dedyl, tetradecyl, heptadecyl, and tocosyl, or an alkyl group such as phenyl, tolyl, xylyl, and naphthyl.

The above compounds have a melting point of 50 to 200°C.

Further, the melting point range is narrow from 0.1°C to 4.5°C, and the melt viscosity is 10°C to 3000°C. In addition, these compounds can generally be dispersed or dissolved in a solvent and have a viscosity of 1 C1p to 2000 c,p, so they can be mixed with colorants and additives for applications other than hot melt coating. It can also be applied to room-temperature coating methods such as gravure coating and silk screen printing.

Each of the above compounds can be obtained by reacting a known compound having an incyanate group with a known compound having an active water system.

Examples of compounds having an incyanate group include methyl isocyanate, ethyl isocyanate, n-propylisocyanate, n-butyl isocyanate, octadecyl incyanate, polymethylene polyphenylisocyanate, 2,4-tolylene diincyanate, 4.4'-
Diphenylmethane diinocyanate, dianidine diisonanate.

meta-xylylene diisocyanate, 1,5-naphthalene diisocyanate, transvinylene diisocyanate, N, N'(4,4/-dimethyl-3,3'-
diphenyl diisocyanate) uredione, 411-2
．． 6-diincyanate methyl caproate, etc.

Triphenylmethane triisocyanate, tris(4-
Phenyl isocyanate thiophosphate) 4゜4'
, 4'-trimethyl-3,3',3'-)diisocyanate-2,4,6-)riphenyl cyanurate, and the like can be used. Or 'various diincyanates that are industrially produced and sold.

For example, ethylene-, tetramethylene-, heptamethylene-, heptamethylene-, octamethylene-, decamethylene-1p-phenylene-1m-phenylene-1m-toluylene-, naphthalene-1,5-, di(p-isocyanyl-cyclohexyl)methane- ,)! Diisocyanates such as J(p-cyanylphenyl)methane-1 can also be used.

In addition, compounds having active hydrogen include -0H1-NH,
, -8H1-COOH and other atomic groups.

Hydrogen peroxide, hydrogen chloride, hydrogen bromide, cyanide, etc. are used.
For example, aliphatic hydrocarbon groups having 1 to 30 carbon atoms, alicyclic hydrocarbon groups, alcohols with -OH added to aromatic hydrocarbon groups, formic acid, i-acid, butyric acid, valeric acid, caprylic acid, palmitic acid Carboxylic acids with 1 to 30 carbon atoms such as, ammonia,
Ethylamine, propylamine 1. Amines having 1 to 30 carbon atoms such as butylamine, amylamine, aniline, ethylnorcaptan, propylmercaptan, butylmercaptan, amylmercaptan, hequinylmercaptan, heptylmercaptan, octylmercaptan,
A thiol having 1 to 30 carbon atoms such as decyl mercaptan is used.

The reaction itself in which a compound having an incyanate group and a compound having an active hydrogen are reacted is known, for example, hNcO+ R/NH2, RNHCONHR'RNCO.
+ R10H, RNHCoOR'RNCO+ R/8H
, RNHCO8R'RNCO+ R/C00) I-, R
Please react like NHCOOCOR', RNHCOR'. Further, in order to assist these reactions, a catalyst may be used as appropriate.

The reason why the above compounds are preferable as binders is that all of these compounds are single compounds and are not mixtures of various compounds like wax', so they have a sharp melting point with an extremely narrow temperature range. It is. In addition, the above compounds have an atomic group -NHCO- in the molecule, and because of this atomic group, the attractive force between the N-H and C-0 station poles acts between adjacent molecules. It has a high melting point even though it has a relatively small molecular weight, and forms a strong film in the solid state.

The reason why the melting point of the above compound is limited to 50"C to 200"C is that if it is less than 50C, it is not preferable as a binder for heat-sensitive recording in terms of color migration and color staining during storage. If the temperature exceeds 200'C, excessive energy is required during thermal recording.

This means that it may damage the thermal recorder, etc. or significantly shorten its lifespan, and may also cause damage to the heat-sensitive recording material or the phenomenon of sticking when the base of the heat-sensitive recording material is plastic or film. This is because it is not a halberd.

Next, a method for manufacturing a sweetfish transfer sheet as an example using the binder described above will be explained.The coloring agent and the binder are kneaded to form a composition, and the composition is coated on one side of the base material by an appropriate coating method. To! ! Just cloth it. In the composition, the colorant and the binder are combined by weight, and the weight of the colorant is 1 to 80%, preferably 2 to 20%.
It is prepared by blending the mixture so that it becomes the following, adding other optional ingredients as necessary, and kneading at room temperature or under heating.

In the above, the colorant is preferably an organic or inorganic dye or pigment that has properties suitable for use as a recording material. For example, it has sufficient color density,
Preferably, it does not change color or fade due to humidity, etc. In addition, some are colorless when not heated, but develop color when heated,
It may be a substance that develops color when it comes into contact with the substance applied to the transfer target.

1. As the base material, any material that is used as a base material for ordinary heat-sensitive transfer notebooks can be used. for example,
polyester resin, polypropylene resin, cellophane,
Cellulose triacetate resin 5 polystyrene resin, polycarbonate bone fat.

Plastics such as polyimide resin, film, glassine paper, condenser paper, ledger paper, Indian paper, etc.
Examples include metal foil and the like and composites of the above materials. Examples of the composite include an aluminum/paper composite, metallized paper, or metallized plastic film. In addition, the thickness of the base material as described above is
From the point of view of thermal conductivity, the thinner the better, usually 2 to 50
μm is preferably 4 to 20 μm. If the weight is less than 2μ, the strength is insufficient and it is difficult to handle, and if the weight exceeds 50μ, the resolution of one character in the printed image decreases, which is not preferred in practice.

One side of the above base material, when used as a heat-sensitive transfer sheet, is coated with a slippery agent such as silicone oil to give it slip properties, and a heat-resistant resin layer is provided on the side that contacts the thermal head when used as a thermal transfer sheet. It is possible to prevent adhesion (referred to as "sticking") to the thermal of the base material, or to prevent sticking by adding a lubricant such as talc or fluororesin powder to the synthetic resin layer. Measures such as prevention may also be used.

In addition, optional components in the above include, for example, softening agents such as mineral or vegetable oils, thermal conductivity improvers such as metal powder, extender pigments such as microsilica, calcium carbonate or kaolin, and transfers such as polyhydric alcohols. A property improver, a solvent, a diluent, etc. can be mentioned. Solvents or diluents are used when the composition is made into an ink composition for ordinary printing methods, and include xylene, toluene, trichloride, white sinter, ethyl acetate, n-butyl acetate, methanol, ethanol, and impropatol. , n-butanol, ethylcyclohexane, ethylcellosolve, butylcellonulp, cyclohexanone, and the like.

Apply the composition as described above to one side of the base material! ! ! The coating methods include hot-melt coating, which involves heating and melting the composition, and regular coating methods, such as gravure coating, roll coating, air knife coating, kiss coating, spray coating, flow coating, and dip coating. , spinner coat, wheeler coat, brush coating, peta coat by silk screen, wire bar code, flow coat, etc., or B, ';
f Labia printing, gravure offset printing, lithographic offset printing,
Printing methods such as sheet printing, die-line printing, intaglio printing, and silk screen printing may also be used.

The thickness of the transfer layer provided as above is 01^
Iris to 1000μ wings, preferably 1μ thick to 100μ
It is. If the weight is less than αlμ, the printing density will not increase and it will be useless for recording, and if it exceeds 1000μ, the thermal conductivity will be poor and transfer will not be sufficient.

Alternatively, the binder of the present invention can also be used in a recording material in which a wax, metal salt, or binder is dispersed in a resin and an opaque layer is provided on a colored support. The support can be formed on the above-mentioned various substrates by a printing method or a coating method using a conventional printing ink consisting of a coloring material such as a pigment or dye of a desired hue, a binder resin, and a solvent. In this case, the optical degree of the colored layer is α2 to 2o, preferably α
6 or more, then heat a composition such as hot-melt coating the heat-sensitive material of the present invention on the colored support,
It is formed using a melting method, a normal printing method, or a coating method. In this case, the thickness is preferably from 1 μm to 1000 μm. If the thickness is less than 1411, the effect of the heat-sensitive material in hiding the colored layer will be reduced and it is not practical. If it is more than 1000 μm, the thermal conductivity will be poor and the colored layer will be hidden. Not visualized. If necessary, a hiding aid may be added to the heat-sensitive material to increase the hiding power, such as inorganic substances such as titanium white and carbon black, various pigments, or dyes. The amount of addition of these hiding aids is from 0.1 to 50 parts per 100 sK of heat-sensitive material.

If it is less than 1 part α, there is no practical effect, and if it is more than 50 parts, the melting characteristics of the heat-sensitive material will deteriorate and the printing quality will deteriorate.

Alternatively, the binder of the present invention can also be used as a single-etching material in which a porous support coated with fusible wax is heated to remove the melted wax and allow ink to pass through. I can do it.

In this case, the porous support may be one made of natural vegetable fibers such as Japanese paper, or one made of various synthetic fibers. In this case, the diameter of the through hole is from 5μ to 100μ.
It's 0μ abuse. If it is smaller than 5 μN, it will be difficult for ink to pass through, and if it is larger than 1000 BN, there will be problems such as dripping of ink or difficulty in forming thin images. The heat-sensitive material is formed on the support to a thickness of 5 μm to 1 mm by a method such as hot-melt coating, in which a composition is applied while being heated and melted, or by a conventional printing method or coating method. If it is thinner than 5 μm, pinholes etc. will occur, and if it is thicker than 1 μm, the thermal conductivity will be poor and long ink passage holes will not be formed.

The recording method for any of the above heat-sensitive recording materials includes, for example, irradiation with thermal energy rays such as four infrared rays to transfer the absorbed heat of the image area to the recording material to copy the image, or thermal It is recorded directly by a device called a head or thermal pen that converts electrical signals into heat.

The binder of the present invention described above has a narrow melting temperature range, and when a heat-sensitive recording material is prepared using such a binder, heat-sensitive recording with a clear image area can be performed, and there is no bleeding or missing areas that are not shown in the record. In addition, the binder of the present invention has high hardness at normal temperatures and excellent retention of colorants, prevents color development due to dark reaction before use, and is resistant to dye migration. It also prevents blocking and has excellent wear resistance. It has the above-mentioned excellent properties and can be applied to normal inking and coating processes.

Examples for explaining the present invention more specifically are listed below.

Example 1 2.6-) Luene diisocyanate and ethyl cellosolve were mixed in such a proportion that the molar ratio of -NCO to -OH was 1=1, and dibutyltin laurate was added as a catalyst in an amount of 0.0% of the total amount of the mixture. 01% by weight was added and stirred continuously for 5 hours while keeping the temperature at 100°C.

After that, the reaction product was collected after cooling and when the 1NCO group near 2300 (1!II-' was checked using an infrared spectrometer needle, no absorption was observed, indicating that -Neo was not present. It was confirmed that the melting point of the reaction product was 1
The temperature was 35-140°C.

Using the reaction product obtained as described above, a composition for hot melt coating was prepared by kneading it in a ball mill for 12 hours while heating it at 100° C. according to the following formulation.

The composition obtained above was placed on a polyester film with a thickness of 6μ, and the film was placed on a hot plate for 170 minutes.
A transfer sheet was prepared by applying wire bar coating to a coating thickness of 2 μm while heating at ℃.

When the composition-coated side of this transfer sheet and high-quality paper with a basis weight of 50 Vrl were stacked together and printed using a thermal printer (manufactured by Shindo Denki, 5P-3080), sharp black print was observed on the surface of the high-quality paper. Obtained.

Example 2 Hexamethylene diisocyanate and ethyl alcohol were mixed so that -NCO and -OH were equimolar, and the mixture was heated at 80°C.
Stir while heating for 10 hours.

The melting point of the product obtained was 83-86 DEG C., and the presence of -NCO could not be detected by infrared spectroscopy.

Using the above product, prepare the following composition using a ball mill,
When stirred at room temperature, the viscosity at 25°C is 300 c, p,
A gravure ink composition was created.

Gravure ink composition Using the obtained gravure ink composition, the thickness was 10/77.
M capacitor paper was coated with gravure coating so that the dry coating thickness was 3 μm, and transferred to make a copy paper, which was printed using a printing machine equipped with Thermal RAD (manufactured by Toshiba, R1610). However, 11 bright red rings were clearly printed.

Example 3 Same as Example 2, except that yellow dye (C,
1,21090), indigo dye (C, 1,74160)
).

Yellow ink using carbon plastic and glue.

Indigo ink and black ink were created.

Using each of the above color inks and the red ink obtained in Example 2, yellow, red, indigo, and black areas were formed sequentially in the printing direction on a 10 μm thick capacitor paper.

Using the transfer sheet produced as above and the thermal paper used in Example 1, first print the desired yellow color while feeding the paper using the yellow area, and then print the desired yellow color on the red area of the transfer paper. Using this, the paper was returned to the yellow printing starting position and the desired red printing was performed, and then indigo and black printing was performed in the same manner, resulting in four color-coded printing.

Example 4 The coated paper from 5 (1 to 1) was subjected to peta-offset printing on the entire surface using a normal black offset ink to obtain a black undercoat paper.

Next, alcohol was mixed with hexamethylene diinocyanate and n-propye so that -NCO and 10H appeared in equimolar proportions, and the mixture was heated at 100°C for 15 hours. The existence of was not recognized. Using the obtained product below &! The sieved product was made into m.

The above composition was applied to the black undercoat paper described in (h) under heating at 110°C so that the coating amount was 72 cm, and letters were written on the coated surface using a thermal pen with a needle tip diameter of 0.10 heated to 120°C. When drawn, clear black characters on a white background were obtained.

Example 5 40 f/d Japanese paper was dip-coated with the following composition under heating at 90°C. The coating amount was 5 F/&.

The above sheet and printed matter were superimposed and plate-made using a Riso Kagaku Kogyo Xenofax FX15QB and Flat V. The above composition was melted and removed in the form of printed letters on one sheet, and then the sheet was placed on a tossha printing machine and printed.

I was able to print a sheet.

Claims (2)

[Claims] (1) A thermosensitive recording binder made of a compound containing an atomic group of %NHCO) in its molecule. (2) The heat-sensitive recording binder according to claim (1), wherein the compound is a compound obtained by reacting a diisocyanate or triisocyanate with an alkyl alcohol or an aryl alcohol.