JP4584663B2

JP4584663B2 - Thermal recording material

Info

Publication number: JP4584663B2
Application number: JP2004284394A
Authority: JP
Inventors: 誠樹米重; 純平夏井; 明人荻野
Original assignee: Nippon Paper Industries Co Ltd
Current assignee: Nippon Paper Industries Co Ltd
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2010-11-24
Anticipated expiration: 2024-09-29
Also published as: JP2006095852A

Description

本発明は、感熱記録体に関し、特に耐水性に優れた感熱記録体に関する。 The present invention relates to a thermal recording material, and more particularly to a thermal recording material excellent in water resistance.

一般に、無色又は淡色の電子供与性染料前駆体（以下染料前駆体という）と染料前駆体と加熱した時に反応して発色させる顕色剤とを主成分とする感熱記録層を有する感熱記録体は、広く実用化されている。この感熱記録体に記録を行うには、サーマルヘッドを内蔵したサーマルプリンター等が用いられるが、このような感熱記録法は、従来実用化された他の記録法に比べて、記録時に騒音がない、現像定着の必要がない、メンテナンスフリーである、機器が比較的安価でありコンパクトである、得られた発色が非常に鮮明であるといった特徴から、情報産業の発展に伴い、ファクシミリやコンピューター分野、各種計測器、ラベル、チケット等に広く使用されてきた。また、屋外用のハンディターミナルや、高保存性が要求される金券用含浸紙などの分野においても、感熱記録体が幅広く使用されるようになっており、光、水、温度などの外的環境に対する耐性や、可塑剤及び油などに対する保存性を向上させる目的で、感熱記録層の上に保護層を設けることが数多く考案されている。
保護層を設けることで保護層面からの耐水性が向上するが、支持体に紙を使用した場合、支持体断面からの吸水により、印字部のにじみやかすれが生じ、文字判別が困難になる場合がある。 In general, a heat-sensitive recording medium having a heat-sensitive recording layer mainly composed of a colorless or light-colored electron-donating dye precursor (hereinafter referred to as a dye precursor) and a color developer that reacts with the dye precursor when heated is developed. Has been widely used. In order to perform recording on this thermal recording medium, a thermal printer or the like with a built-in thermal head is used. Such a thermal recording method has no noise during recording as compared with other recording methods that have been put to practical use. The development of the information industry has led to the development of the facsimile and computer fields, because there is no need for development and fixing, maintenance is free, the equipment is relatively inexpensive and compact, and the resulting color development is very clear. It has been widely used for various measuring instruments, labels, tickets, etc. In addition, thermal recording media are widely used in fields such as outdoor handy terminals and impregnated paper for vouchers that require high storage stability. External environments such as light, water, and temperature are also being used. Many attempts have been made to provide a protective layer on a heat-sensitive recording layer for the purpose of improving the resistance to heat resistance and the storage stability against plasticizers and oils.
Providing a protective layer improves water resistance from the surface of the protective layer, but when paper is used for the support, water absorption from the cross section of the support may cause bleeding and blurring of the printed part, making it difficult to distinguish characters There is.

この支持体断面からの吸水を防止するため、支持体に吸湿性の極めて少ないフィルムを用いる方法も提案されているが、感熱層形成工程での、乾燥ムラによる外観不良が発生しやすいこと、高コストになることなどの問題がある。また、支持体にフィルムを用いると、吸水性に加えて通気性も低下するため、最上層に気密性の高い保護層を形成した感熱記録体では印字時、保存時に塗工層の膨れを生じることもある。さらに、吸水性の低いフィルムは一般に、静電気を発生しやすく、保管時の埃付着が顕著である問題もある。
また、紙を支持体に用いたものとして、特許文献１では支持体にスチレン・アクリル系樹脂を含浸させた含浸紙を用いた感熱記録体が、特許文献２では支持体にカチオン変性ポリ（メタ）アクリルアミド含有液を塗布若しくは含浸させた含浸紙を用いた感熱記録体が、それぞれ開示されているが、十分な耐水性を得ることはできていない。
特開平６−２４７０４２号公報特開２０００−２６３９３３号公報 In order to prevent water absorption from the cross section of the support, a method using a film with extremely low hygroscopicity for the support has also been proposed, but the appearance defect due to drying unevenness in the heat-sensitive layer forming process is likely to occur. There are problems such as cost. In addition, when a film is used as the support, the air permeability is lowered in addition to the water absorption, and therefore the thermal recording material having a highly airtight protective layer formed on the uppermost layer causes swelling of the coating layer during printing and storage. Sometimes. Further, a film having low water absorption generally tends to generate static electricity, and there is a problem that dust adhesion during storage is significant.
In addition, as a material using paper as a support, in Patent Document 1, a heat-sensitive recording material using an impregnated paper in which a support is impregnated with styrene / acrylic resin is used, and in Patent Document 2, a cation-modified poly (meta) is used as a support. ) Thermal recording media using impregnated paper coated or impregnated with an acrylamide-containing liquid are disclosed, but sufficient water resistance cannot be obtained.
JP-A-6-247042 JP 2000-263933 A

本発明は、上記課題を解決した、耐水性の高い感熱記録体を提供することである。 An object of the present invention is to provide a heat-sensitive recording material with high water resistance that solves the above-described problems.

本発明は、支持体にガラス転移点20℃以上の合成樹脂および撥水剤を含有する含浸紙を用いることで上記課題を解決できることを見出した。
すなわち、本発明は、支持体上に、無色ないし淡色の塩基性無色染料と該塩基性無色染料と反応して発色させる顕色剤とを主成分として含有する感熱記録層を設けた感熱記録体において、支持体が、ガラス転移点２０℃以上１００℃以下のアクリル樹脂及び/又はスチレン樹脂、および撥水剤を含有する含浸紙であって、含浸紙中の合成樹脂および撥水剤が２重量％以上３０重量％未満であり、且つ合成樹脂／撥水剤の比率が８０/２０から９８/２の範囲であり、且つ撥水剤がワックス類またはアルキルケテンダイマー、アルケニル無水コハク酸であることを特徴とする感熱記録体である。含浸紙中の合成樹脂および撥水剤の２成分が２重量％以上３０重量％未満、且つ合成樹脂／撥水剤の比率が８０/２０から９８/２の範囲にすることで感熱記録層の強度も良好な感熱記録体を得ることができ、撥水剤がワックス類またはアルキルケテンダイマー、アルケニル無水コハク酸を用いることで、生産性も良好な感熱記録体を得ることができる。 The present invention has found that the above problem can be solved by using an impregnated paper containing a synthetic resin having a glass transition point of 20 ° C. or higher and a water repellent for the support.
That is, the present invention provides a heat-sensitive recording material comprising, on a support, a heat-sensitive recording layer containing, as a main component, a colorless or light-colored basic colorless dye and a color developer that reacts with the basic colorless dye to develop a color. In the above, the support is an impregnated paper containing an acrylic resin and / or a styrene resin having a glass transition point of 20 ° C. or higher and 100 ° C. or lower, and a water repellent, and the synthetic resin and the water repellent in the impregnated paper are 2 wt. % To less than 30% by weight, the ratio of synthetic resin / water repellent is in the range of 80/20 to 98/2, and the water repellent is a wax, an alkyl ketene dimer, or an alkenyl succinic anhydride. Is a heat-sensitive recording material . The two components of the synthetic resin and water repellent in the impregnated paper are 2% by weight or more and less than 30% by weight, and the ratio of the synthetic resin / water repellent is in the range of 80/20 to 98/2. A heat-sensitive recording material with good strength can be obtained, and a heat-sensitive recording material with good productivity can be obtained by using waxes, alkyl ketene dimers, or alkenyl succinic anhydride as the water repellent.

本発明の樹脂及び撥水剤含有含浸紙を支持体に用いた感熱記録体は、水浸透性が小さく、水に浸漬しても印字部の劣化がなく耐水性に優れている。 The heat-sensitive recording material using the resin and the water repellent-containing impregnated paper of the present invention as a support has low water permeability and is excellent in water resistance without deterioration of the printed part even when immersed in water.

本発明に用いる支持体は、ガラス転移点２０℃以上の合成樹脂および撥水剤を含有する含浸紙であることを特徴としている。
本発明において、合成樹脂のガラス転移点は２０℃以上であることが必要である。ガラス転移点が２０℃未満であると、含浸した合成樹脂膜が柔らかすぎるため、感熱記録体塗工工程や製品保管時に温湿度変化によって生じる含浸紙の収縮を抑制することができず、波打やカールなどの問題を生じる。また、合成樹脂のガラス転移点が２０℃未満であると含浸後の乾燥工程において、ドライヤー装置を汚してしまうといった操業上の問題が発生する。一方、合成樹脂のガラス点移転が高すぎると造膜性が低下する傾向があるため、耐水性が低下する可能性がある。このた合成樹脂のガラス点移転は１２０℃以下が好ましく、更に１００℃以下が好ましい。
本発明において、含浸紙中の合成樹脂と撥水剤の成分が２重量％以上３０重量％未満であり、合成樹脂／撥水剤の比率は８０/２０から９８/２の範囲であることが好ましい。合成樹脂成分の含有比率や撥水剤の配合比率が低いと、耐水性が不十分となり、逆に樹脂成分の含有比率や撥水剤の配合比率が高いと、この支持体上とこの支持体上に形成されるアンダー層、感熱記録層などとの密着性が低下するため、アンダー層、感熱記録層などの脱落、塗膜強度が出にくくなるといった問題を生じる。
本発明において、２３℃５０％Rhの雰囲気で調湿した感熱記録体を４cm角に断裁し試験片を作製し、試験前の重量を測定した。静置した容器に水を入れ、この中に試験片を浸漬し、２４時間放置し取り出した。表裏に過剰に付着した水を拭き取り、重量を測定し、次式により水浸透量を算出した水浸透性の値が２５ｇ／ｍ^２以下であることが好ましく、更に好ましくは２０ｇ／ｍ^２以下である。水浸透性の値が２５ｇ／ｍ^２以上であると印字部の耐水性が低下する。
水浸透量(g/m²)＝(試験後の重量(g)−試験前の重量(g))／(１６／１００００)(m²) The support used in the present invention is characterized by being an impregnated paper containing a synthetic resin having a glass transition point of 20 ° C. or higher and a water repellent.
In the present invention, the glass transition point of the synthetic resin needs to be 20 ° C. or higher. If the glass transition point is less than 20 ° C., the impregnated synthetic resin film is too soft, so that the shrinkage of the impregnated paper caused by temperature and humidity changes during the heat-sensitive recording material coating process or product storage cannot be suppressed. And problems such as curling. Further, if the glass transition point of the synthetic resin is less than 20 ° C., an operational problem that the dryer device is soiled in the drying step after impregnation occurs. On the other hand, if the glass point transfer of the synthetic resin is too high, the film-forming property tends to be lowered, so that the water resistance may be lowered. The glass point transfer of these synthetic resins is preferably 120 ° C. or lower, more preferably 100 ° C. or lower.
In the present invention, the components of the synthetic resin and the water repellent in the impregnated paper are 2% by weight or more and less than 30% by weight, and the ratio of the synthetic resin / water repellent is in the range of 80/20 to 98/2. preferable. When the content ratio of the synthetic resin component and the mixing ratio of the water repellent are low, the water resistance becomes insufficient. Conversely, when the content ratio of the resin component and the mixing ratio of the water repellent is high, the support and the support Since the adhesiveness with the under layer and the heat-sensitive recording layer formed on the surface is lowered, there arises a problem that the under layer and the heat-sensitive recording layer are not removed and the coating film strength is difficult to be obtained.
In the present invention, a heat-sensitive recording material conditioned in an atmosphere of 23 ° C. and 50% Rh was cut into a 4 cm square to prepare a test piece, and the weight before the test was measured. Water was put into a stationary container, a test piece was immersed in the container, and left for 24 hours to be taken out. The water adhering excessively on the front and back is wiped off, the weight is measured, and the water permeability calculated by the following formula is preferably 25 g / m ² or less, more preferably 20 g / m ² or less. is there. When the water permeability is 25 g / m ² or more, the water resistance of the printed portion is lowered.
Water penetration amount (g / m ² ) = (weight after test (g) −weight before test (g)) / (16/10000) (m ² )

本発明で用いる合成樹脂は、水溶性合成樹脂または水分散性合成樹脂であって、乾燥後水不溶性になり、ガラス転移点が２０℃以上である合成樹脂である。合成樹脂としては、例えば、アクリル樹脂、酢酸ビニル樹脂、スチレン樹脂、オレフィン樹脂、エポキシ樹脂、ウレタン樹脂およびポリエステル樹脂とこれらの誘導体が挙げられ、単独または併用して使用することができる。また、操業条件（特に乾燥条件）によって、適切な物性値（融点、軟化点、最低造膜温度など）を有する合成樹脂を適宜選択することができる。
本発明において、用いる撥水剤としては、例えば、水分散性のワックス類、アルキルケテンダイマー、シリコン系樹脂、フッ素系樹脂、アルケニル無水コハク酸（ＡＳＡ）などが挙げられるが、特に制限されるものではない。合成樹脂と撥水剤を含有した支持体とこの支持体上に設けられるアンダー層や感熱記録層との密着性の点から、高い撥水性を有するシリコーン系樹脂やフッ素系樹脂より、水分散性のワックス類、アルキルケテンダイマー（ＡＫＤ）、アルケニル無水コハク酸（ＡＳＡ）などを用いることが好ましい。 The synthetic resin used in the present invention is a water-soluble synthetic resin or a water-dispersible synthetic resin, which becomes water-insoluble after drying and has a glass transition point of 20 ° C. or higher. Examples of the synthetic resin include acrylic resin, vinyl acetate resin, styrene resin, olefin resin, epoxy resin, urethane resin, polyester resin, and derivatives thereof, and these can be used alone or in combination. Further, a synthetic resin having appropriate physical properties (melting point, softening point, minimum film-forming temperature, etc.) can be appropriately selected depending on the operating conditions (particularly drying conditions).
Examples of the water repellent used in the present invention include water-dispersible waxes, alkyl ketene dimers, silicone resins, fluorine resins, alkenyl succinic anhydride (ASA), and the like. is not. From the viewpoint of adhesion between a support containing a synthetic resin and a water repellent and the under layer and heat-sensitive recording layer provided on the support, water dispersibility is higher than that of silicone resins and fluorine resins having high water repellency. It is preferable to use waxes, alkyl ketene dimer (AKD), alkenyl succinic anhydride (ASA) and the like.

本発明における水分散性のワックス類は特に限定されないが、例えば、カルナバワックス等の植物系ワックス、ラノリンワックス等の動物系ワックス、パラフィンワックス等の石油系ワックス、ポリエチレンワックス等の合成ワックスが使用可能である。また、操業条件（特に乾燥条件）によって、適切な物性値（融点、軟化点など）を有する合成樹脂を適宜選択することができる。
本発明において、アルキルケテンダイマーは下記１式で表される。 Water-dispersible waxes in the present invention are not particularly limited. For example, plant waxes such as carnauba wax, animal waxes such as lanolin wax, petroleum waxes such as paraffin wax, and synthetic waxes such as polyethylene wax can be used. It is. Further, a synthetic resin having appropriate physical property values (melting point, softening point, etc.) can be appropriately selected depending on operating conditions (particularly drying conditions).
In the present invention, the alkyl ketene dimer is represented by the following formula 1.

Ｒ_１−ＣＨ＝Ｃ − Ｏ
｜｜
Ｒ_２−ＣＨ−Ｃ＝Ｏ１式 R ₁ —CH═C—O
｜｜
R ₂ —CH—C═O Formula 1

（式中Ｒ_１、Ｒ_２は炭素数８〜３０の炭化水素を表す。） (In the formula, R ₁ and R ₂ represent a hydrocarbon having 8 to 30 carbon atoms.)

合成樹脂および撥水剤を含浸する原紙は、合成樹脂および撥水剤を均一に含浸するため低いサイズ性あるいは無サイズ紙を使用することが好ましい。高いサイズ性の原紙を使用した場合、合成樹脂および撥水剤が原紙表面に偏った分布になるため、断面からの水の浸透を抑制することが困難になる可能性がある。
厚さおよび坪量は、ラベル用途、チケット用途など感熱記録体の使用目的により選択されるが、使用するパルプ等の種類は制限されない。また、原紙抄造時には、顔料、填料、染料、含浸紙力向上剤、定着剤などの添加が可能である。
合成樹脂および撥水剤の含浸方法は、抄紙工程の中間に設置されたサイズプレスコーター、ゲートロールコーター、エアナイフコーター、コンマコーター、バーコーター等の含浸機、あるいは塗工機により含浸処理が可能である。また、オフマシンで上記の含浸機、あるいは塗工機での含浸処理も可能である。更に、パルプと混合（内添）して含浸することも可能であり、特に制限されるものではないが、合成樹脂および撥水剤を均一に含浸させるには抄紙工程の中間に設置されたサイズプレスコーターを用いるが好ましく、また、生産性の点からも好ましい。
上記合成樹脂含有含浸紙を支持体として、淡色の塩基性無色染料と該塩基性無色染料と反応して発色させる顕色剤とを主成分として含有する感熱記録層を形成し、感熱記録体を得る。感熱記録層に用いる材料は、特に限定しない。また、感熱記録層上に保護層を設けても良い。支持体裏面にバック層を設けても良い。 As the base paper impregnated with the synthetic resin and the water repellent, it is preferable to use a low size or non-size paper in order to uniformly impregnate the synthetic resin and the water repellent. When a high-size base paper is used, since the synthetic resin and the water repellent agent are distributed unevenly on the surface of the base paper, it may be difficult to suppress the penetration of water from the cross section.
The thickness and basis weight are selected depending on the purpose of use of the thermal recording material such as labeling and ticketing, but the type of pulp used is not limited. In addition, pigments, fillers, dyes, impregnated paper strength improvers, fixing agents and the like can be added during base paper making.
The impregnation method of synthetic resin and water repellent can be impregnated by an impregnation machine such as a size press coater, gate roll coater, air knife coater, comma coater, bar coater, etc. installed in the middle of the paper making process. is there. Further, the above impregnation machine or impregnation treatment with a coating machine can be performed off-machine. Furthermore, it is possible to impregnate by mixing (internal addition) with pulp, and it is not particularly limited. However, in order to uniformly impregnate the synthetic resin and the water repellent, the size installed in the middle of the papermaking process A press coater is preferably used, and also from the viewpoint of productivity.
Using the synthetic resin-containing impregnated paper as a support, a heat-sensitive recording layer containing a light-colored basic colorless dye and a developer that develops color by reacting with the basic colorless dye as a main component is formed. obtain. The material used for the thermosensitive recording layer is not particularly limited. Further, a protective layer may be provided on the thermosensitive recording layer. A back layer may be provided on the back surface of the support.

以下に本発明の感熱記録体を実施例によって説明する。
実施例および比較例で作製した支持体の片面に、アンダー層、感熱発色層、保護層を形成し、他方の面にバック層を形成した。尚、説明中、部及び％はそれぞれ重量部及び重量％を示す。感熱記録体の各塗工層に用いた、塗料を以下のように調製した。 The thermosensitive recording material of the present invention will be described below with reference to examples.
An under layer, a thermosensitive coloring layer, and a protective layer were formed on one side of the support produced in Examples and Comparative Examples, and a back layer was formed on the other side. In the description, parts and% indicate parts by weight and% by weight, respectively. The paint used for each coating layer of the thermal recording material was prepared as follows.

［アンダー層塗料調整］
焼成カオリン（エンゲルハード社製アンシレックス）５０．０部
スチレン−ブタジエン共重合体ラテックス（固形分５０％）５０．０部
水５０．０部
上記組成よりなる混合物を混合攪拌してアンダー層塗料を調成した。 [Under layer paint adjustment]
Firing kaolin (Ansilex manufactured by Engelhard) 50.0 parts Styrene-butadiene copolymer latex (solid content 50%) 50.0 parts Water 50.0 parts The mixture of the above composition is mixed and stirred to form an underlayer paint. Prepared.

［感熱発色層塗料調整］
下記配合の顕色剤分散液（Ａ液）、及び塩基性無色染料分散液（Ｂ液）を、それぞれ別々にサンドグラインダーで平均粒子径１ミクロンになるまで湿式磨砕を行った。
Ａ液（顕色剤分散液）
４−ヒドロキシ−４’−イソプロポキシジフェニルスルホン６．０部
ポリビニルアルコール１０％水溶液１８．８部
水１１．２部
Ｂ液（塩基性無色染料分散液）
３−ジブチルアミノ−６−メチル−７−アニリノフルオラン（ＯＤＢ−２）
２．０部
ポリビニルアルコール１０％水溶液４．６部
水２．６部 [Adjustment of heat-sensitive coloring layer paint]
The developer dispersion liquid (A liquid) and the basic colorless dye dispersion liquid (B liquid) having the following composition were separately wet-ground with a sand grinder until the average particle diameter became 1 micron.
Liquid A (developer dispersion)
4-hydroxy-4'-isopropoxydiphenylsulfone 6.0 parts polyvinyl alcohol 10% aqueous solution 18.8 parts water 11.2 parts Liquid B (basic colorless dye dispersion)
3-Dibutylamino-6-methyl-7-anilinofluorane (ODB-2)
2.0 parts polyvinyl alcohol 10% aqueous solution 4.6 parts water 2.6 parts

次いで下記の割合で分散液を混合して記録層の塗液とした。
記録層塗液
Ａ液（顕色剤分散液）３６．０部
Ｂ液（塩基性無色染料分散液）９．２部
微粉シリカ（３０％分散液）３３．３部
ポリビニルアルコール１０％水溶液２５部 Subsequently, the dispersion liquid was mixed at the following ratio to obtain a recording layer coating liquid.
Recording layer coating liquid A liquid (developer dispersion) 36.0 parts B liquid (basic colorless dye dispersion) 9.2 parts fine silica (30% dispersion) 33.3 parts polyvinyl alcohol 10% aqueous solution 25 parts

［保護層塗料調整］
水酸化アルミ３０．０部
ポリビニルアルコール（クラレ社製:PVA117）１０％水溶液３０．０部
水４０．０部
［バック層塗料調整］
水酸化アルミ３０．０部
ポリビニルアルコール（クラレ社製:PVA117）１０％水溶液３０．０部
水４０．０部 [Protective layer paint adjustment]
Aluminum hydroxide 30.0 parts Polyvinyl alcohol (Kuraray Co., Ltd .: PVA117) 10% aqueous solution 30.0 parts Water 40.0 parts [Back layer coating preparation]
Aluminum hydroxide 30.0 parts Polyvinyl alcohol (Kuraray Co., Ltd .: PVA117) 10% aqueous solution 30.0 parts Water 40.0 parts

上記、アンダー層塗料、感熱発色層塗料、保護層塗料およびバック層塗料を、下記の実施例１〜６および比較例１〜６に記した支持体に塗工し、感熱記録体を作製した。
支持体上にアンダー層塗料を乾燥後の塗布量が１０g/m²となるよう塗工しアンダー含浸紙を得た。次いで、アンダー層の上に感熱発色層塗料を乾燥後の塗布量が６g/m²となるよう塗工し、さらにその上に保護層塗料を乾燥後の塗布量が3g/m²となるよう塗工した。最後に、裏面にバック層塗料を乾燥後２g/m²となるよう塗工し、感熱記録体を得た。この感熱記録体を４０℃環境下に３日間放置し、保護層とバック層を反応させた。
得られた、感熱記録体の水浸透量、印字部の耐水性、耐熱膨れおよび塗膜強度を評価した。評価方法を以下にまとめた。 The under layer coating material, heat sensitive color developing layer coating material, protective layer coating material and back layer coating material were applied to the supports described in Examples 1 to 6 and Comparative Examples 1 to 6 to prepare a heat sensitive recording material.
The underlayer paint was applied onto the support so that the coating amount after drying was 10 g / m ² to obtain an under-impregnated paper. Next, the thermosensitive coloring layer coating is applied on the under layer so that the coating amount after drying is 6 g / m ^2, and further the coating amount after drying the protective layer coating is 3 g / m ^2. Coated. Finally, the back layer coating was applied to the back surface so as to be ² g / m ² after drying to obtain a heat-sensitive recording material. This heat-sensitive recording material was left in a 40 ° C. environment for 3 days to react the protective layer and the back layer.
The water penetration amount of the obtained heat-sensitive recording material, the water resistance of the printed part, the heat swell and the coating strength were evaluated. The evaluation methods are summarized below.

［水浸透量］
２３℃５０％Rhの雰囲気で調湿した感熱記録体を４cm角に断裁し試験片を作製し、試験前の重量を測定した。静置した容器に水を入れ、この中に試験片を浸漬し、２４時間放置し取り出した。表裏に過剰に付着した水を拭き取り、重量を測定し、次式により水浸透量を算出した。
水浸透量(g/m²)＝(試験後の重量(g)−試験前の重量(g))／(１６／１００００)(m²)
［印字部の耐水性］
作製した感熱記録含浸紙を、感熱プリンタ（マークポイントプリンター：マークポイント社製）でバーコード（CODE３９）を印字し、試験片を作製した。静置した容器に水を入れ、この中に試験片を浸漬し、３日間放置し取り出した。自然乾燥後、バーコードリーダーで読みとり試験を行った。
にじみなし、読みとり可能：○
にじみ有り読みとり可能：△
読みとり不可：× [Water penetration]
A heat-sensitive recording material conditioned in an atmosphere of 23 ° C. and 50% Rh was cut into a 4 cm square to prepare a test piece, and the weight before the test was measured. Water was put into a stationary container, a test piece was immersed in the container, and left for 24 hours to be taken out. The water adhering excessively to the front and back was wiped off, the weight was measured, and the water penetration amount was calculated by the following formula.
Water penetration amount (g / m ² ) = (weight after test (g) −weight before test (g)) / (16/10000) (m ² )
[Water resistance of printed part]
A barcode (CODE 39) was printed on the produced thermal recording impregnated paper with a thermal printer (mark point printer: manufactured by Mark Point) to prepare a test piece. Water was put into a stationary container, a test piece was immersed in the container, and left for 3 days to be taken out. After natural drying, a reading test was conducted with a barcode reader.
Judged, readable: ○
Can be read with blurring: △
Cannot read: ×

［加熱膨れ］
ガスライターで裏面を加熱し発色させた。
膨れなし：○、膨れ発生：×
［塗膜強度］
感熱塗膜面にセロテープ（日東No.29）を貼り付け、ゆっくり剥がした。
塗膜剥離なし：○、塗膜剥離有り：× [Heating blister]
The back side was heated with a gas lighter to develop color.
No blistering: ○, blistering occurrence: ×
[Coating strength]
A cellophane tape (Nitto No. 29) was applied to the surface of the heat-sensitive coating and slowly peeled off.
No coating peeling: ○, Coating peeling: ×

［実施例１］
ガラス転移点２４℃の水分散型スチレンアクリル系樹脂共重合体（商品名：EK６１、サイデン化学（株）社製）９０重量部と水分散型ワックスエマルジョン（商品名：EW１０００、双葉化学（株）製）１０重量部の固形分重量比で混合し、この合成樹脂と撥水剤の混合液を坪量１００ｇ/ｍ^２の無サイズの上質紙にテーブル含浸機で均一に含浸した後、シリンダ乾燥器で乾燥（１０５℃）し、合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液の含有率は１０重量％であった。 [Example 1]
90 parts by weight of water-dispersed styrene acrylic resin copolymer (trade name: EK61, made by Seiden Chemical Co., Ltd.) with a glass transition point of 24 ° C. and water-dispersed wax emulsion (trade name: EW1000, Futaba Chemical Co., Ltd.) (Made by mixing) 10 parts by weight of solid content and mixing this synthetic resin and water repellent liquid uniformly into non-size high-quality paper with a basis weight of 100 g / m ² with a table impregnator, followed by cylinder drying It was dried (105 ° C.) with a vessel to prepare an impregnated paper support containing a mixed solution of a synthetic resin and a water repellent. The content of the mixed solution of the synthetic resin and the water repellent was 10% by weight.

［実施例２］
実施例１の合成樹脂と撥水剤の混合液を水で３倍に希釈した以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は、２重量％であった。 [Example 2]
An impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared in the same manner as in Example 1, except that the mixed solution of the synthetic resin and the water repellent of Example 1 was diluted three times with water. . The content of the mixed liquid component of the synthetic resin and the water repellent was 2% by weight.

［実施例３］
実施例１の含浸工程を３回繰り返した以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は、２０重量％であった。 [Example 3]
An impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared in the same manner as in Example 1 except that the impregnation step of Example 1 was repeated three times. The content of the mixed liquid component of the synthetic resin and the water repellent was 20% by weight.

［実施例４］
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を８０/２０に変更し、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。
［実施例５］
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を98/2に変更し、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。 [Example 4]
The ratio of the styrene acrylic resin copolymer of Example 1 and the wax emulsion was changed to 80/20, and an impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared in the same manner as in Example 1. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.
[Example 5]
The ratio of the styrene acrylic resin copolymer of Example 1 to the wax emulsion was changed to 98/2, and an impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was produced in the same manner as in Example 1. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.

［実施例６］
実施例１のワックスエマルジョンをアルキルケテンダイマー（商品名：サイズパインＳＫＳ２８７、荒川化学工業（株）製）に変更し、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。
［参考例１］
ガラス転移点１１３℃の水分散型スチレンアクリル系樹脂共重合体（商品名：LS97、岐阜セラック（株）社製）を用いた以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。 [Example 6]
The wax emulsion of Example 1 was changed to an alkyl ketene dimer (trade name: Size Pine SKS287, manufactured by Arakawa Chemical Industries, Ltd.), and impregnation containing a mixture of a synthetic resin and a water repellent was performed in the same manner as in Example 1. A paper support was prepared. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.
[ Reference Example 1 ]
A synthetic resin and a water repellent were prepared in the same manner as in Example 1 except that a water-dispersed styrene acrylic resin copolymer (product name: LS97, manufactured by Gifu Shellac Co., Ltd.) having a glass transition point of 113 ° C. was used. An impregnated paper support containing the mixed solution was prepared. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.

［実施例８］
実施例１のワックスエマルジョンをアルケニル無水コハク酸エマルジョン（ＡＳ−１５２２（星光ＰＭＣ社製）４部（固形分換算）に対してＳＰ−１８０２（星光ＰＭＣ社製）１部(固形分換算)で乳化したもの）に変更し、実施例１と同じ方法で樹脂含有含浸紙を作製した。合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。
［参考例２］
実施例１の合成樹脂と撥水剤の混合液を水で5倍に希釈した以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は、1重量％であった。 [Example 8]
The wax emulsion of Example 1 was emulsified with 1 part (converted to solid content) of SP-1802 (produced by Seiko PMC) to 4 parts (converted to solid content) of alkenyl succinic anhydride emulsion (AS-1522 (produced by Seiko PMC)). The resin-containing impregnated paper was produced in the same manner as in Example 1. An impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.
[ Reference Example 2]
An impregnated paper support containing a mixture of a synthetic resin and a water repellent was prepared in the same manner as in Example 1 except that the mixture of the synthetic resin and the water repellent was diluted five times with water. . The content of the mixed liquid component of the synthetic resin and the water repellent was 1% by weight.

[実施例１０]
実施例１の含浸工程を５回繰り返した以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は、３５重量％であった。
［参考例３］
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を９９／１に変更し、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。 [Example 10]
An impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared in the same manner as in Example 1 except that the impregnation step of Example 1 was repeated 5 times. The content of the mixed liquid component of the synthetic resin and the water repellent was 35% by weight.
[ Reference Example 3]
The ratio of the styrene acrylic resin copolymer of Example 1 and the wax emulsion was changed to 99/1, and an impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was produced in the same manner as in Example 1. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.

［参考例４］
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を75/25に変更し、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。
［実施例１３］
ガラス転移点８０℃の水分散型アクリル系樹脂（商品名：ヨドゾールＡＤ５３、日本ＮＳＣ社製）を用いた以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。 [Reference Example 4]
The ratio of the styrene acrylic resin copolymer of Example 1 and the wax emulsion was changed to 75/25, and an impregnated paper support containing a mixed solution of a synthetic resin and a water repellent was prepared in the same manner as in Example 1. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.
[Example 13]
Impregnation containing a mixed solution of a synthetic resin and a water repellent in the same manner as in Example 1 except that a water-dispersed acrylic resin having a glass transition point of 80 ° C. (trade name: Yodosol AD53, manufactured by NSC Japan) was used. A paper support was prepared. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.

[比較例１]
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を１００／０（撥水剤無配合）に変更し、実施例１と同じ方法で合成樹脂を含有した含浸紙支持体を作製した。合成樹脂の含有率は１０重量％であった。
［比較例２］
ガラス転移点１０℃の水分散型スチレンアクリル系樹脂共重合体（商品名：AD-81B、日本エヌエスシー（株）社製）を用いた以外は、実施例１と同じ方法で合成樹脂と撥水剤の混合液を含有した含浸紙支持体を作製した。合成樹脂と撥水剤の混合液成分の含有率は１０重量％であった。 [Comparative Example 1]
The ratio of the styrene acrylic resin copolymer of Example 1 and the wax emulsion was changed to 100/0 (without water repellent), and an impregnated paper support containing a synthetic resin was produced in the same manner as in Example 1. The content of the synthetic resin was 10% by weight.
[Comparative Example 2]
Synthetic resin and water repellent properties were the same as in Example 1 except that a water-dispersed styrene acrylic resin copolymer having a glass transition point of 10 ° C. (trade name: AD-81B, manufactured by Nippon SC Co., Ltd.) was used. An impregnated paper support containing a liquid mixture of liquid medicine was prepared. The content of the mixed liquid component of the synthetic resin and the water repellent was 10% by weight.

［比較例３］
坪量１１０ｇ／ｍ^２の上質紙を支持体として用いた。
［比較例４］
坪量１２５ｇ／ｍ^２のPETフィルム（商品名：ＯＬＷ１２５、帝人（株）製）を支持体として用いた。
[比較例５]
実施例１のスチレンアクリル樹脂共重合体とワックスエマルジョンの比率を０／１００（合成樹脂無配合）に変更し、実施例１と同じ方法で撥水剤を含有した含浸紙支持体を作製した。撥水剤の含有率は２重量％であった。
実施例および比較例の性能について、表１，２に示した。 [Comparative Example 3]
A high-quality paper having a basis weight of 110 g / m ² was used as a support.
[Comparative Example 4]
A PET film (trade name: OLW125, manufactured by Teijin Limited) having a basis weight of 125 g / m ² was used as a support.
[Comparative Example 5]
The ratio of the styrene acrylic resin copolymer of Example 1 and the wax emulsion was changed to 0/100 (no synthetic resin blended), and an impregnated paper support containing a water repellent was produced in the same manner as in Example 1. The content of the water repellent was 2% by weight.
The performance of Examples and Comparative Examples is shown in Tables 1 and 2.

上記の表２に示されるように、本発明の樹脂含有紙を支持体に用いた感熱記録体は、水浸透性が小さく、水に浸漬しても印字部の劣化がなく耐水性に優れていた。一方、支持体中の樹脂含有量が０％の比較例５とワックスエマルジョンの配合比率が０％の比較例１は水浸透性が大きく、水浸漬により印字のにじみが生じた。ガラス転移点１０℃のスチレンアクリル樹脂を用いた比較例２は塗工工程での波打が大きかった。支持体が樹脂含有紙でない比較例３は水浸透性が極めて大きく、耐水性が低かった。支持体にPETフィルムを用いた比較例６は加熱膨れを生じた。
As shown in Table 2 above, the heat-sensitive recording material using the resin-containing paper of the present invention as a support has low water permeability and excellent water resistance without deterioration of the printed part even when immersed in water. It was. On the other hand, Comparative Example 5 in which the resin content in the support was 0% and Comparative Example 1 in which the blending ratio of the wax emulsion was 0% had high water permeability, and printing blur occurred due to water immersion. In Comparative Example 2 using a styrene acrylic resin having a glass transition point of 10 ° C., the waviness in the coating process was large. In Comparative Example 3 in which the support was not a resin-containing paper, the water permeability was extremely high and the water resistance was low. In Comparative Example 6 in which a PET film was used as the support, heating blistering occurred.

Claims

In the heat-sensitive recording layer, on which a heat-sensitive recording layer containing as a main component a colorless or light-colored basic colorless dye and a developer that develops color by reacting with the basic colorless dye is provided. An impregnated paper containing an acrylic resin and / or a styrene resin having a glass transition point of 20 ° C. or higher and 100 ° C. or lower, and a water repellent, wherein the synthetic resin and the water repellent in the impregnated paper are 2 wt% or more and less than 30 wt%. And the ratio of synthetic resin / water repellent is in the range of 80/20 to 98/2, and the water repellent is a wax, an alkyl ketene dimer, or an alkenyl succinic anhydride. body.