JP6391114B2 - Thermal transfer recording media for embedding cassettes - Google Patents

Description

The present invention relates to a thermal transfer recording medium for an embedding cassette used for preparation of a specimen such as a histopathological examination.

Conventionally, as a method for inspecting a biological sample taken from a human body or a laboratory animal, or performing a histopathological examination, the biological sample is sliced very thinly and then subjected to various staining to prepare a biological specimen. A method of inspecting by microscopic observation is known.
The biological specimen at the time of this inspection is prepared by the following procedure.
Procedure 1. A sample taken out from a living body is immersed in formalin, and the biological sample is fixed and placed in an embedding cassette, or the sample is placed in the embedding cassette and immersed in formalin together with the embedding cassette to fix the sample.
Procedure 2. The sample is immersed in alcohol (methanol or ethanol) together with the embedding cassette, and the moisture and formalin inside the sample are replaced with alcohol.
Procedure 3. The sample is immersed in either xylene, acetone, or chloroform together with the embedding cassette, and the alcohol inside the sample is replaced with xylene, acetone, or chloroform.
Procedure 4. The sample is immersed in paraffin (melting point: about 50 ° C. to about 60 ° C.) melted together with the embedding cassette, and xylene, acetone, or chloroform inside the sample is replaced with paraffin.
Procedure 5. After the inside of the sample is replaced with paraffin, the molten paraffin in which the sample is immersed together with the embedding cassette is cooled, so that the sample becomes an embedding block embedded in solid paraffin. The voids initially filled with moisture are also filled with solid paraffin.
Procedure 6. The embedded block is cut to a thickness of about 2 μm to 5 μm suitable for microscopic observation to produce a thin section and stained to prepare a biological specimen.

In this specimen preparation method, even if the biological sample is a soft tissue by embedding the biological sample with paraffin, it can be sliced into an ultrathin suitable for microscopic observation without destroying its form. However, since molten paraffin is not compatible with formalin, even if a biological sample fixed with formalin is immersed in molten paraffin as it is, the molten paraffin does not penetrate into the biological sample. Therefore, a biological specimen is prepared according to the above procedure.

This embedding cassette used for the preparation of biological specimens is used to prevent sample dissipation and breakage during specimen preparation and to facilitate handling of specimens during preparation of biological specimens. In order to come into contact with formalin, alcohol, xylene, acetone, chloroform, molten paraffin, etc., resistance to each organic solvent is required. Generally, polyacetal or polypropylene is used as the material.

In some cases, hundreds of biological samples are processed at one time, and information is entered in the embedding cassette body for confirmation and management of the contents of the sample. A typical embedding cassette is provided with a display entry portion having an angle of approximately 45 degrees on the front surface of the embedding cassette in order to enter information. On the surface of this display entry part, when the paraffin adhering to the embedding cassette surface after the paraffin is cooled and solidified, it is easy to exfoliate the paraffin, and the entered information adheres to the exfoliated paraffin. In order not to drop off, fine irregularities are provided.

Since the embedding cassette body comes into contact with formalin, alcohol, xylene, acetone, chloroform, and molten paraffin according to the above procedure, the information entered must be resistant to each organic solvent. Further, after the paraffin is cooled and solidified, it is necessary to firmly fix the paraffin to the display entry portion so that the paraffin does not fall off.

As a method of entering information in the display entry part, a method of printing on a label and attaching the label is introduced. (Patent Document 1) However, in this method, the label may be peeled off during specimen preparation and storage. Also, a method of directly printing on the display entry portion using an ink jet printer has been introduced. (Patent Document 2) In this method, an ultraviolet curable ink is used because of the need for solvent resistance. However, if the ink is cured with ultraviolet rays in order to provide sufficient solvent resistance, the ink itself is strong. However, the adhesiveness with the display entry portion was lowered, and the printing sometimes dropped when the paraffin was peeled off.

In addition, there is a method of directly printing on a display entry portion of an embedding cassette by a thermal transfer printer using a thermal transfer recording medium coated with a thermal transfer ink. In order to sufficiently fix the ink printed on the unevenness of the display entry portion by this printing method, it is necessary to transfer the ink under high pressure contact and high temperature conditions. Under such printing conditions, when overprinting is performed using a thermal transfer recording medium provided with yellow, magenta, and cyan ink layers, and if necessary, a black ink layer in a surface sequential manner, the previously printed ink is semi-melted. Since overprinting of two or more colors is performed in this state, when the color ink layer of the thermal transfer recording medium is composed mainly of wax, the thermal transfer head is moved up and down, or the cassette or the thermal transfer recording medium is moved. There has been a problem that printing stains occur due to friction between the printed portion and the thermal transfer recording medium.

JP 2007-46988 A JP 2002-365184 A

In the present invention, even if the colored ink layer of the thermal transfer recording medium is composed mainly of wax, the overcoat layer is composed mainly of polyethylene wax and a resin obtained by curing a curable resin with a curing agent. In order to sufficiently fix the printed ink on the uneven surface of the display entry part surface of the polyacetal or polypropylene embedding cassette, it is excellent that there is no printing stain even when printing under high pressure contact and high temperature conditions It is an object of the present invention to provide a heat-sensitive transfer recording medium which can perform overprinting of two or more colors and has good solvent resistance against formalin, alcohol, acetone, xylene, molten paraffin and the like.

As a result of intensive studies, the inventor has determined that the thermal transfer recording medium has a configuration in which a colored ink layer and an overcoat layer are laminated in this order on a base material, and a colored ink layer containing wax as a main component is yellow. An ink layer, a magenta ink layer, a cyan ink layer, and if necessary, a black ink layer are provided in a surface sequential manner, and the main component of the overcoat layer is polyethylene wax and a resin obtained by curing a curable resin with a curing agent. Even if the colored ink layer of the heat-sensitive recording medium is mainly composed of wax, printing stains on the uneven surface of the display entry part surface of the polyacetal or polypropylene embedding cassette under high pressure contact and high temperature printing conditions And good color overprinting, and good solvent resistance against formalin, ethanol, acetone, xylene, etc. It found that to be, and have completed the present invention.

The first invention is a thermal transfer recording medium for an embedding cassette used when preparing a biological specimen in a pathological examination or the like, wherein a colored ink layer and an overcoat layer are laminated in this order on a substrate. The colored ink layer mainly composed of wax is provided in a surface sequential manner of a yellow ink layer, a magenta ink layer, a cyan ink layer, and, if necessary, a black ink layer, and the overcoat layer is made of polyethylene wax, a curable resin. A heat-sensitive transfer recording medium for an embedding cassette, characterized by comprising a resin obtained by curing a resin as a main component.

The second invention is characterized in that the overcoat layer has a thickness of 1.5 to 3.5 μm, the overcoat layer contains 20 to 65% by weight of a resin obtained by curing a curable resin with a curing agent , and a polyethylene wax The thermal transfer recording medium for embedding cassettes according to the first aspect of the present invention, characterized by containing 10 to 65% by weight.

A third invention is the heat-sensitive transfer recording medium for an embedding cassette according to the first invention or the second invention, wherein the curable resin is a soluble cellulose resin.

Even if the colored ink layer of the heat-sensitive recording medium is composed mainly of wax, the overcoat layer is composed of polyethylene wax, and a resin obtained by curing a curable resin with a curing agent as a main component. Even if printing is performed under high-pressure contact and high-temperature conditions in order to sufficiently fix the printed ink to the uneven surface of the display entry part surface of the embedding cassette made of polypropylene, a good color with no print stains Overprinting is possible and printing with good solvent resistance against formalin, ethanol, acetone, xylene, molten paraffin, etc. can be obtained.

The thermal transfer recording medium for the embedding cassette has a constitution in which a colored ink layer and an overcoat layer are laminated in this order on a base material, and a colored ink layer mainly composed of wax is used as a yellow ink layer and a magenta ink layer. A cyan ink layer and, if necessary, a black ink layer are provided in a surface sequential manner, and the overcoat layer is made of polyethylene wax and a resin obtained by curing a curable resin with a curing agent .

As the substrate, various known substrates are used as substrates for conventional heat-sensitive transfer recording media, but a polyester film of 2 to 10 μm is particularly preferable from the viewpoint of durability, thermal conductivity, and cost.

The colored ink layer of the present invention comprises a wax as a main component and a colorant added. Examples of the wax include natural waxes such as wax, carnauba wax, candelilla wax, montan wax and ceresin wax, petroleum waxes such as paraffin wax and microcrystalline wax, and synthetic waxes such as oxidized wax, ester wax and polyethylene wax. Higher fatty acids can be used. Moreover, you may add a thermoplastic resin as needed. Examples of the thermoplastic resin include olefin copolymers such as ethylene vinyl acetate copolymer, polyamide resin, polyester resin, natural rubber, petroleum resin, rosin resin, styrene resin, acrylic resin, and methacrylic resin. can give.

As the colorant of the colored ink layer, various known pigments and known dyes can be used. For example, pigments such as azo, phthalocyanine, quinacridone, thioindigo, anthraquinone, isoindoline, and carbon black Can be given. These can be used in combination of two or more. The amount of the colorant is preferably 10 to 25% by weight of the entire colored ink layer from the viewpoint of transferability and printing density. In addition, an additive such as a pigment dispersant can be appropriately added to the colored ink layer within a range not impairing the object of the present invention.

The thickness of the colored ink layer is preferably 1.0 to 4.0 μm in terms of good printing and sensitivity. When the thickness is less than 1.0 μm, the image density is insufficient. When the thickness exceeds 4.0 μm, the thermal sensitivity is lowered and good printing is prevented.

Further, in the thermal transfer recording medium for the embedding cassette of the present invention, layers having various functions may be provided between the colored ink layer and the substrate as long as the object of the present invention is not impaired. Layers with various functions include a primer layer that prevents the colored ink layer from peeling off, a protective layer that protects the printed surface after transfer, and improved transferability, allowing the colored ink layer to peel off from the substrate. Examples include a release layer that helps. Note that a plurality of these layers may be stacked.

The primer layer of the present invention is preferably composed mainly of a flexible resin having adhesiveness to the substrate and the colored ink layer from the viewpoint of preventing peeling of the substrate and the colored ink layer. Examples of the resin having the above-described characteristics include urethane resins, urethane-modified polyester resins, vinyl acetate resins, ethylene vinyl acetate copolymer resins, ethylene ethyl acetate copolymer resins, and synthetic rubber resins such as styrene-isoprene resins. . A plurality of these resins may be used in combination.

The overcoat layer of the present invention is mainly composed of polyethylene wax and a resin obtained by curing a curable resin with a curing agent . Examples of the curable resin include soluble cellulose resin, epoxy resin, acrylic resin, methacrylic resin, urethane resin, polyester resin, alkyd resin, polyamide resin and the like. A soluble cellulose resin is preferably used from the viewpoint.

Examples of the soluble cellulose resin used in the present invention include methyl cellulose, ethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose, carboxyethyl cellulose, nitrocellulose, cellulose acetate, CAP (cellulose acetate propionate), CAB (cellulose acetate butyrate). Rate). As these soluble cellulose resins, those in which hydroxyl groups of cellulose are not substituted and hydroxyl groups remain are used for curing with a curing agent. Among these soluble cellulose resins, nitrocellulose is preferably used from the viewpoint of good handleability at the time of coating and good printing.

As the curing agent used in the present invention, known curing agents such as isocyanates, melamines, and epoxys can be used, but isocyanate curing agents are preferably used because of good handleability during coating operations. It is done. Examples of the isocyanate-based curing agent include TDI (tolylene diisocyanate), HMDI (hexamethylene diisocyanate), XDI (xylene diisocyanate), IPDI (isophorone diisocyanate), and general known isocyanates made of these polymers. be able to.

The content of the polyethylene wax in the overcoat layer is preferably 10 to 65% by weight. If the content of the polyethylene wax is less than 10% by weight, transferability is lowered. Further, the transferability is lowered, so that the fixing force of the ink to the display entry portion of the embedding cassette is lowered and the solvent resistance tends to be lowered. On the other hand, when the content of the polyethylene wax is more than 65% by weight, the ratio of the resin obtained by curing the curable resin with a curing agent is relatively lowered, and it becomes difficult to exhibit the effect of preventing printing stains.

The content of the resin obtained by curing the curable resin of the overcoat layer with a curing agent is preferably 20 to 65% by weight. When the content of the resin obtained by curing the curable resin with a curing agent is less than 20% by weight, it is difficult to exhibit the effect of preventing printing stains during overprinting. On the contrary, when the content of the resin obtained by curing the curable resin with a curing agent is more than 65% by weight, the transferability is lowered. Further, the transferability is lowered, so that the fixing force of the ink to the display entry portion of the embedding cassette is lowered and the solvent resistance tends to be lowered.

Moreover, you may add a thermoplastic resin to the said overcoat layer as needed. Examples of the thermoplastic resin include olefin copolymers such as ethylene vinyl acetate copolymer, polyamide resin, polyester resin, natural rubber, petroleum resin, rosin resin, styrene resin, acrylic resin, and methacrylic resin. However, acrylic resins and methacrylic resins are preferably used from the viewpoint of transferability to polyacetal resin and polypropylene resin, which are the materials of the embedding cassette, and heat resistance and solvent resistance during high-temperature printing.

The coating thickness of the overcoat layer is preferably in the range of 1.5 to 3.5 μm. If the thickness is less than 1.5 μm, the strength of the overcoat layer is insufficient, and the function of preventing printing stains is difficult to be exhibited. When it is thicker than 3.5 μm, transferability is lowered.

When using the thermal transfer recording medium of the present invention in a printer using a thermal head, silicone resin, fluororesin, nitrocellulose resin or modified by these on the back side of the substrate sliding with the thermal head, For example, various heat-resistant layers such as silicone-modified urethane resin and silicone-modified acrylic resin, or a conventionally known stick prevention layer made of a material obtained by mixing a lubricant with these heat-resistant resins may be provided.

The thermal transfer recording medium of the present invention can also be applied to cases where a thermal head other than the thermal head is used as the heat source for thermal transfer. For example, a typeface (hot stamp) heated as a heat source can be used.

EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated in detail, this invention is not restrict | limited to the following Example. In the examples, “parts” represents parts by weight unless otherwise specified.

(Examples 1-9, Comparative Examples 1-3)
On one side of a 6.0 μm-thick polyethylene terephthalate film, a stick prevention layer ink composed of a silicone acrylic resin of the following formulation was applied with a gravure coater, dried with hot air at 98 ° C. for 10 seconds, and then dried. Was adjusted to 0.2 μm, and a stick prevention layer was provided.
(Stick prevention layer ink)
Silicone-modified acrylic resin (Saimak 290 manufactured by Toa Gosei Co., Ltd.) 15.0 parts Polyisocyanate (Takenate D-110N manufactured by Mitsui Chemicals, Inc.) 0.3 part Methyl ethyl ketone 54.7 parts Toluene 30.0 parts

(Examples 1-9, Comparative Examples 1-3)
The following primer layer ink is coated on the surface of the polyethylene terephthalate film provided with the stick prevention layer on the side opposite to the stick prevention layer with a gravure coater, and dried for 1 minute with hot air at 60 ° C. to obtain a thickness after drying. A primer layer was provided by adjusting so as to be 0.3 μm.
(Primer layer ink)
Urethane-modified polyester resin (molecular weight: 32000, Tg: −22 ° C., elongation at break: 1000%, solid content: 30%)
18.0 parts Toluene 41.0 parts Methyl ethyl ketone 41.0 parts

(Examples 1-9, Comparative Examples 1-3)
On the primer layer, the following colored ink layer ink was dissolved in a hot melt coater at 130 ° C. and coated surface-sequentially, and colored inks of 1.8 μm in thickness of yellow, magenta, cyan, and black Each layer was formed.
(Colored ink layer ink: Black)
Carnauba wax 28.0 parts Polyethylene wax (melting point about 110 ° C) 49.0 parts Carbon black 20.0 parts Dispersant 3.0 parts

(Colored ink layer ink: Yellow)
Carnauba wax 35.0 parts Polyethylene wax (melting point: about 110 ° C.) 46.0 parts Disazo Yellow 16.0 parts (CI Pigment Yellow-14)
Dispersant 3.0 parts

(Colored ink layer ink: magenta)
Carnauba wax 35.0 parts Polyethylene wax (melting point about 110 ° C.) 49.0 parts Brilliant Carmine 6B 14.0 parts (CI PigmentRed-57: 1)
Dispersant 2.0 parts

(Colored ink layer ink: cyan)
Carnauba wax 31.5 parts Polyethylene wax (melting point: about 110 ° C.) 52.5 parts Phthalocyanine blue 14.0 parts (CI Pigment Blue-15: 3)
Dispersant 2.0 parts

(Examples 1-9, Comparative Examples 1-3)
On the colored ink layer, the overcoat coating liquid prepared with the composition shown in Table 1 was applied with a gravure coater and dried with warm air at 60 ° C. for 1 minute. The overcoat layers of the examples and comparative examples were formed so as to have the thicknesses shown in Table 1, and heat cured at 45 ° C. for 48 hours to obtain thermal transfer recording media of the examples and comparative examples. .

The evaluation results of each Example and Comparative Example are shown in Table 2, and each evaluation method is shown below.

(Transferability evaluation)
Using the thermal transfer printer dedicated to the embedding cassette (SCP-M type, manufactured by PRIMERA, USA), the black ink part of the thermal transfer recording medium of each example and comparative example is printed on the display and entry part of the polyacetal embedding cassette. The result was visually determined. Judgment criteria are as follows.
○: Printing is good.
X: Printing is not good and there is a problem in practical use.

(Print stain evaluation)
Using the thermal transfer printer dedicated to the embedding cassette (SCP-M type, manufactured by PRIMERA, USA), print on the display area of the polyacetal embedding cassette with the black ink portion of the thermal transfer recording medium of each example and comparative example. The result was visually determined. Judgment criteria are as follows.
A: There is no print stain.
○: Although there is a minute print stain, there is no practical problem.
X: There is a print stain and there is a problem in practical use.

(Print overlap evaluation)
Using the thermal transfer printer dedicated to the embedding cassette (SCP-M type manufactured by PRIMERA, USA), print on the display area of the polyacetal embedding cassette with the magenta ink portion of the thermal transfer recording medium of each example and comparative example. went. Thereafter, overprinting was performed with the cyan ink portion on the magenta ink printing portion, and the result was visually determined. Judgment criteria are as follows.
(Double-circle): Printing overlaps and there is no disorder and overprinting is favorable.
○: Although there is a slight disturbance in the overlap of printing, there is no practical problem.
X: Overprinting is disturbed, and there is a problem in practical use.

(Solvent resistance evaluation)
Using the thermal transfer printer dedicated to the embedding cassette (SCP-M type, manufactured by PRIMERA, USA), print on the display area of the polyacetal embedding cassette with the black ink portion of the thermal transfer recording medium of each example and comparative example. The embedded cassette printed was immersed in xylene, acetone, ethanol, formalin and molten paraffin solvents for 1 minute each. Thereafter, the embedding cassette was taken out from each soaked solvent, and within 5 seconds, the display entry portion was rubbed three times with a finger wearing a rubber glove, and the change in printing was visually determined. Judgment criteria are as follows.
A: Printing does not change.
○: Printing is slightly dissolved, but there is no practical problem.
X: The printing is dissolved and there is a problem in practical use.

(Print adhesion evaluation)
Using the thermal transfer printer dedicated to the embedding cassette (SCP-M type, manufactured by PRIMERA, USA), print on the display area of the polyacetal embedding cassette with the black ink portion of the thermal transfer recording medium of each example and comparative example. The printed embedding cassette was immersed in 80 ° C. dissolved paraffin and cooled at room temperature for 6 hours to solidify the paraffin. Thereafter, the embedding cassette was taken out from the solidified paraffin, and the change in printing when the paraffin adhering to the display entry portion was peeled off with a finger was visually determined. Judgment criteria are as follows.
A: Printing does not change.
○: The printed matter adheres to the solidified paraffin and falls off from the cassette display entry part, but there is no practical problem.
X: The printing adheres to the solidified paraffin and falls off from the cassette display entry portion, which causes a practical problem.

It is a top view of the Example of the thermal transfer recording medium of this invention. It is sectional drawing of the Example of the thermal transfer recording medium of this invention. It is sectional drawing of the Example of the thermal transfer recording medium (with a primer layer) of this invention.

DESCRIPTION OF SYMBOLS 1 Overcoat layer 2 Colored ink layer: Yellow 3 Colored ink layer: Magenta 4 Colored ink layer: Cyan 5 Colored ink layer: Black 6 Base material 7 Stick prevention layer 8 Primer layer

Claims (3)

A thermal transfer recording medium for embedding cassettes used in the preparation of biological specimens for pathological examinations, etc., comprising a colored ink layer and an overcoat layer laminated in this order on a substrate, with wax as the main component The colored ink layer is provided in a surface sequential manner of a yellow ink layer, a magenta ink layer, a cyan ink layer, and if necessary a black ink layer. The overcoat layer is cured with polyethylene wax and a curable resin with a curing agent. A heat-sensitive transfer recording medium for an embedding cassette, characterized by comprising a resin as a main component. The overcoat layer has a thickness of 1.5 to 3.5 μm , contains 20 to 65% by weight of a resin obtained by curing a curable resin with a curing agent in the overcoat layer, and 10 to 65% by weight of polyethylene wax. The heat-sensitive transfer recording medium for embedding cassettes according to claim 1, wherein The thermal transfer recording medium for an embedding cassette according to claim 1, wherein the curable resin is a soluble cellulose resin.

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