JP2006143825A - Removable pressure-sensitive adhesive composition for laminate and its application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressing removable adhesive composition for adhesive layer not impairing a series of processing workability consisting of pressing/laminating/conveying of a sealer carrying out processing into a hidden postcard, etc., by laminating papers, etc., for continuous business form in which an adhesive layer is provided and excellent in sealer processing. <P>SOLUTION: The removable pressure-sensitive adhesive composition comprises (A) 100 pts.wt. adhesive main component being a (meth)acrylate-based emulsion having 60-90% gel fraction and obtained by carrying out emulsion polymerization of (a) 90-98.95 pts.wt. (meth)acrylic acid alkyl ester, (b) 1-5 pts.wt. carboxyl group-containing monomer and (c) 0.05-5 pts.wt. monomer having either one functional group selected from an epoxy group, a hydroxy group, a silanol group and methylol group, (B) 0.5-5 pts.wt. phosphate-based surfactant and (C) 40-300 pts.wt. filler obtained by combining organic fine powder with inorganic fine powder. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive releasable pressure-sensitive adhesive composition for bonding, and more specifically, as a pressure-sensitive adhesive layer provided on bi-fold or tri-fold continuous form paper such as concealment postcards, confidential postcards, sealed letters, etc. The adhesive composition can be re-peeled and can be re-peeled, and such Z-folded form paper is continuously supplied to the sealer device, and is applied while being pressed, bonded and conveyed via the rotating pressure roller. The present invention relates to a pressure-sensitive adhesive re-peeling pressure-sensitive adhesive composition for bonding, which is excellent in processing workability of a sealer device, and an application using the pressure-sensitive adhesive composition.

  Conventionally, in various fields, tape-like, film-like or sheet-like paper, and organic resin materials have been used as bonding members and covering members. The adhesive tape, pressure-sensitive adhesive sheet or pressure-sensitive adhesive film coated with a pressure-sensitive adhesive on one side or both sides of such a material as a bonding member or a covering member is excellent in handling and workability during processing or actual use. Is widely used. In addition, the specifications of such materials are pressure-bonding properties and enable re-peeling, have initial adhesiveness as a function of the pressure-sensitive adhesive, and can be easily and easily re-peeled after bonding. It is something that can be done. Since they are temporarily bonded and re-peeled in this way, they are used as surface protection / rust prevention coating materials before use of various new material surfaces and as label materials for various displays.

  In recent years, in order to cope with the increasing and diversification of e-mail business in offices, schools, government offices, etc., by utilizing the adhesive function that can be re-separated as needed by temporary bonding by such crimping. Concealment / confidential information such as invoices, notices, etc. and various information / notification information for the purpose of enabling quick, low-cost, temporary privacy protection (or secret concealment) Or, it can be mailed in a concealed form as a sealed letter, and it can be peeled off again to peel off, open and confirm specific information.

  When processing such concealment postcards, confidential postcards, sealed letters, etc., an adhesive composition (hereinafter sometimes simply referred to as an adhesive) was applied to a predetermined part of one or both sides of a continuous form paper. Bonded products are made by pressure-bonding while conveying bi-fold or tri-fold continuous forms. Therefore, in such a series of processing operations, the coated adhesive does not exhibit and remove the initial adhesive force with respect to the cut paper as the support of the adhesive layer, The pressure-sensitive adhesive layer coated on the support is easily bonded and bonded to the paper substrate on the opposite bonding surface under pressure, but the pressure-sensitive adhesive layer is peeled off when transferred again. Furthermore, during a series of processing operations, it is usually desirable not to exert adhesive force on the surface of a rotary roll type member that is conveyed while being crimped.

  Therefore, for example, in [Patent Document 1], various adherends such as masking tapes and sheets, display labels, and the like, which can be bonded and re-peeled by applying a pressure-sensitive adhesive to paper or a synthetic resin film of a support. Adhesives that are optimal for pasting to the skin have been proposed. The pressure-sensitive adhesive used in such specifications can exert an adhesive force on the adherend and can be easily peeled off as appropriate. Moreover, it is an adhesive which does not leave an adhesive on a to-be-adhered body after peeling and does not contaminate. For this purpose, [Patent Document 1] includes (meth) acrylic acid ester having 4 to 12 carbon atoms in the alkyl group as a main component, and (meth) acrylic acid, vinyl acetate, itaconic acid, maleic anhydride and the like. It is described that an acrylic emulsion-type pressure-sensitive adhesive containing 1 to 10 parts by weight of a phosphate ester surfactant is suitably used for 100 parts by weight of a monomer mixed with a polymerizable unsaturated monomer. . Furthermore, it is described that an epoxy compound, a polyisocyanate compound, or the like is added as a crosslinking agent.

  [Patent Document 2] includes an acrylic emulsion obtained by emulsion polymerization of an alkyl acrylate having an alkyl group having 4 to 12 carbon atoms, (meth) acrylonitrile, and an α, β-unsaturated carboxylic acid, and A pressure-sensitive acrylic emulsion type containing a phosphate ester emulsifier has been proposed which is excellent in anti-glue resistance to an adherend after re-peeling. In particular, it is described that the addition effect of the phosphate ester emulsifier is a component that balances the retention strength against the adherend by exerting the effect of suppressing the improvement in adhesive strength over time in relation to the removability. .

  [Patent Document 3] includes 50 to 99.9 wt% of (meth) acrylic acid alkyl ester having 4 to 14 carbon atoms in the alkyl group, adhesion to the support, and initial adhesion to the adherend. Involved in adhesion, 5 to 0.1% by weight of a carboxyl group-containing monomer such as (meth) acrylic acid, itaconic acid, maleic acid, and in relation to initial adhesion, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate Polymer latex 100 obtained by emulsion polymerization of 0 to 45% by weight of a functional monomer such as glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, N, N-dimethyl (meth) acrylamide, etc. For parts by weight, re-peelability and re-adhesion to the adherend after re-peeling (re-peeling useful for surface protection film, coating masking tape, adhesive memo, etc. For possible to provide a pressure-sensitive adhesive sheet), removable pressure-sensitive adhesive of the pressure-sensitive containing a 0.1-3 parts by weight of a specific phosphoric ester surfactants have been described.

  Further, as an application using such a pressure-sensitive adhesive and re-peelable pressure-sensitive adhesive, for example, [Patent Document 4] describes a tri-fold pressure-bonded postcard in which a pressure-sensitive adhesive layer is provided on both sides of a paper support. Has been proposed. As the pressure sensitive adhesive, natural rubber latex, vulcanized natural rubber latex, which is a natural rubber resin, and 100 parts by weight of natural rubber latex obtained by graft polymerization of MMA are involved in blocking resistance and printing ink acceptance. An adhesive comprising 90 to 400 parts by weight of an inorganic filler such as charcoal cal, kaolin, silica, or miker is disclosed. In addition, it is described that cellulose powder, various starches, methyl methacrylate beads and other powders are added as organic fillers in order to improve adhesive strength, blocking resistance and slipperiness.

In [Patent Document 5], an organic filler such as 50 to 300 parts by weight of starch or the like is added to 100 parts by weight of latex of a (meth) acrylic acid ester polymer obtained by an emulsion polymerization method in order to adjust the adhesive force. There has been proposed a releasable adhesive composition comprising a combination of an inorganic filler such as synthetic silica, talc, kaolin, and miker.

  [Patent Document 6] describes, as an adhesive resin, 100 parts by weight of a dried product of a self-crosslinking acrylic emulsion, an inorganic filler such as silica, charcoal cal, kaolin clay and starch having an average particle diameter of 1 to 20 μm, starch, and the like. A releasable (pseudoadhesive) adhesive composition containing 5 to 250 parts by weight of a filler as a combination addition amount of the organic filler has been proposed.

JP 60-0675779 JP 2001-040313 A JP 09-316407 Japanese Patent Application Laid-Open No. 08-238872 JP 09-310056 A JP 09-263743

  As described above, in many fields, adhesive tapes, adhesive films, and adhesive sheets that take advantage of adhesive properties that are releasable in the initial adhesiveness (or temporary bonding adhesiveness) of adhesives have been ( 1) As a bonded display member for labels, labels, stickers, etc., (2) As a secret leakage prevention coating material, (3) As an anti-scratch coating protection material for various new materials before use, (4) Contamination resistance, It is a specification as a rust-proof surface protective material and is widely used as a bonded covering member.

  When processing and actually using such a member, the pressure-sensitive adhesive exhibits an initial adhesive force on a tape-like or film-like or sheet-like paper body or synthetic resin body that is a support for the pressure-sensitive adhesive layer, On the other hand, the pressure-sensitive adhesive layer applied to the support is not separated from the support, and the other side such as a paper body, a synthetic resin body, a metal body, and a ceramic body on the surface to be oppositely bonded in actual use. It is desirable that the pressure-sensitive adhesive is bonded to the adherend under pressure bonding and the adhesive layer is not peeled off from the support and transferred to the adherend surface at the time of re-peeling.

That is, from the past, after such a temporary pasting adhesion, the adhesive layer applied with the specification to re-peel,
(1) On a smooth adherend surface such as glass, metal, ceramics, plastic, paper, and wood without being detached from the support surface,
(2) The initial adhesiveness can be easily and appropriately exerted by pressure bonding, and after bonding under pressure bonding, unless forcibly removed,
(3) The pressure-sensitive adhesive layer exhibits a corresponding predetermined peel adhesive strength,
(4) Adhesive properties that can be easily re-peeled from the adherend surface, and when peeling,
(5) The pressure-sensitive adhesive layer is peeled off from the support surface and is not transferred to the adherend surface, which is the opposite bonding surface. It is important that the pressure-sensitive adhesive layer is a so-called pressure-sensitive adhesive layer that is peeled off during re-peeling and does not contaminate the adherend surface.

  However, depending on the type of the pressure-sensitive adhesive, the support, the adherend, etc., it can be re-peeled as needed by temporarily bonding and bonding under a predetermined pressure. In addition, it has been proposed to allow various types of pressure-sensitive adhesive (or pressure-bonding) re-peeling, with specifications that enable anti-contamination without adhesion and contamination to the adherend due to peeling of the adhesive layer or transfer. There is a tendency that the specifications of the mold pressure-sensitive adhesive do not necessarily satisfy the specifications sufficiently.

  Therefore, the product is processed by making use of the adhesive properties that are initial adhesiveness (or temporary bonding adhesiveness), removability, and transfer resistance (or contamination resistance) as a working effect under such pressure bonding. As already described above, the application trends of the pressure-sensitive adhesive appropriately reflected at the time of the processing operation to be performed include concealment postcards, confidential postcards, sealed letters and the like that have been rapidly spreading in recent years.

That is, in these bonding products, from the viewpoint of the pressure-sensitive adhesive applied to the support, the pressure-sensitive adhesive support is a form paper, and the facing surface to be bonded is an adherend form paper or The opposite surface may also be a form paper provided with an adhesive layer. Moreover, the adhesive layer for bonding applied to the form paper is temporarily bonded and bonded under a predetermined pressing force, and the adhesive property that can be re-removed as needed during actual use is utilized. .
In addition, conventionally, such a bonded product usually continuously supplies bi-fold or tri-fold continuous form paper provided with an adhesive layer satisfying such specifications to a rotating roller portion of a sealer. In general, it is made into a product under pressure bonding / bonding / conveying.

  Therefore, particularly when processing such products, the pressure-sensitive adhesive layer coated on the support sheet is applied to the rotating roller member surface of the sealer that conveys the form sheet while being crimped. Do not detract from the roller work surface by exerting adhesive force, or impair the workability of the sealer to be crimped / bonded / conveyed due to this adhesive layer.

  However, in the above-mentioned [Patent Document 1], as a masking tape, a sheet, and a label that can be bonded and re-peeled by applying an adhesive to the support paper, synthetic paper, and resin film, various coating materials can be used. The most suitable adhesive for sticking to a kimono has been proposed. The pressure-sensitive adhesive used for such specifications has an adhesive force to the adherend and can be easily removed again, and the adherend without peeling remains on the adherend after peeling. It is described as an adhesive that does not contaminate the body.

Furthermore, in [Patent Document 4], a coated pressure-sensitive adhesive layer is bonded and pressure-bonded to an adherend, which is also a paper body, under pressure. Also disclosed is a tri-fold pressure-bonded postcard in which a pressure-sensitive adhesive layer that can be peeled again is provided on a cut sheet of a support on which an adhesive layer is provided from a paper body that is an adherend.
As a pressure-sensitive adhesive and re-peelable pressure-sensitive adhesive resin composition,
(1) 100 parts by weight of a natural rubber latex, a natural rubber latex, a vulcanized natural rubber latex, or a natural rubber latex obtained by graft polymerization of MMA,
(2) An adhesive resin composition comprising a combination of 90 to 400 parts by weight of an inorganic filler such as charcoal cal, kaolin, silica, or miker,
Furthermore, in order to improve adhesion control, blocking resistance and slipperiness,
(3) It is described that cellulose powder, starch, methyl methacrylate beads and the like are added as organic fillers.

  Therefore, the pressure-sensitive adhesive layer properties that are temporarily bonded and bonded as described above and can be re-removed as appropriate are well-known properties that have been conventionally demonstrated for ordinary re-peelable pressure-sensitive adhesives. It can also be said.

Furthermore, as already mentioned above, it is a re-peeling type adhesive, and it is a concealing postcard that is continuously produced under pressure bonding / bonding / conveying while supplying the processed paper to the rotating pressure roller of the sealer. It can also be said that it is a well-known fact that the adhesives satisfy the following requirements (1) to (3) for a series of processing operations such as:
(1) The tape-like or sheet-like continuous form paper that is the support of the pressure-sensitive adhesive layer does not desorb by exhibiting the initial adhesive force,
(2) On the other hand, the coating pressure-sensitive adhesive layer coated on the support does not peel off and transfer to the adherend of the paper sheet on the opposite lamination surface,
(3) Furthermore, at the time of a series of processing, it is important that the pressure-sensitive conveying roll member surface to be conveyed while being pressure-bonded is at least an adhesion-stain-resistant pressure-sensitive adhesive without exerting adhesive force. is there.

  Further, as is apparent from the description of [Patent Document 1] to [Patent Document 6], which has been conventionally proposed as an emulsion-type or latex-type re-peelable pressure-sensitive adhesive, the pressure-sensitive adhesive of the pressure-sensitive adhesive used for such applications is used. As a characteristic, it is disclosed that it is a pressure-sensitive adhesive having an initial adhesiveness (or temporary bonding adhesiveness) and a releasable adhesive property under pressure bonding. However, referring to the workability of making a bonded product under pressure bonding / bonding / conveying due to its adhesive properties, the sealer that turns the continuous form paper into a product while being crimped / bonded / conveyed rotates. The relationship between the workability related to the roller, the pressure-sensitive adhesive sufficiently satisfying such specifications, and the pressure-sensitive adhesive properties are not necessarily clarified.

  That is, an adhesive layer is coated in advance on one side or both sides of a bi-fold or tri-fold form paper continuously supplied to the sealer. Further, usually, predetermined printing items including concealment information are printed including the adhesive layer. The adhesive layer coated on this paper has a series of crimping, bonding, and conveyance processes for the workability of the sealer, which makes such a sheet into a bonded product while being conveyed by a rotating roller. In the work, it is understood that the pressure-bonding adhesive property that is temporarily bonded under pressure and is a re-peelable type that can be re-peeled as appropriate, balances the work. Therefore, how the pressure-sensitive adhesive properties (hereinafter referred to as pressure-sensitive adhesive layer properties) of the pressure-sensitive adhesive layer provided on such form paper are related to the workability of the sealer and what pressure-sensitive adhesive is used. Whether the workability can be satisfied, the actual re-peeling adhesive has not yet been sufficiently disclosed and evaluated.

  Therefore, an object of the present invention is to use in the present invention when a re-peelable pressure-sensitive adhesive layer is provided on a paper body of a support such as a concealment postcard, a confidential postcard, or a sealed letter. The main component of the adhesive for the adhesive / adhesive layer is extremely simple in its production method, low in cost, processed into a support for adhesive, or excellent in handling and workability in actual use. The pressure-sensitive adhesive layer is to provide a pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition having a (meth) acrylic acid ester emulsion as a main component of the pressure-sensitive adhesive that enables predetermined printing and printing.

  That is, for the pressure-sensitive adhesive peelable adhesive composition according to the present invention to be provided as a suitable material for such applications, as an important issue to be further improved from the past, in connection with the processability of the bonded product, Concealed postcards and confidential documents that are related to the rotating roller of the sealer that is crimped, bonded, and transported, and is processed continuously as a bi-fold or tri-fold continuous form with an adhesive layer, while being crimped, bonded, and transported. It is to provide a pressure-sensitive adhesive composition excellent in processing workability for processing a product on a postcard, a sealed letter or the like.

  Another object of the present invention is to provide a concealing postcard, confidential postcard, sealed letter, etc. provided as a printing layer with an adhesive layer that does not impair the workability of the sealer.

  Therefore, as a result of earnest examination of these problems, the present inventor, for example, continuously puts a confidential three-fold postcard or a three-fold sealed letter through a sealer that is a rotary pressure-conveying and carrying roller that performs such a processing operation. When performing the combined processing, it is not only to evaluate the pressure bonding property by the rotating roller of the sealer to be conveyed by pressure bonding and the rotation conveying property at the roller portion.

  That is, the surface of the form paper that is continuously supplied / conveyed is coated with a pressure-sensitive adhesive layer that is adhesively bonded and removable under pressure bonding. Therefore, the present inventor made the form sheet suitable for balancing the adhesive layer characteristics with the adhesion roller resistance and the adhesion resistance against the rotating pressure roller surface where the sealer rotates. We found that the workability of the sealer, which is continuously supplied and continuously and effectively bonded and transported, greatly affects the workability of the sealer, and has printability as a postcard and sealed letter, and is pasted as a postcard and sealed letter. The inventors have invented a desired pressure-sensitive adhesive composition for a pressure-removable pressure-sensitive adhesive layer that is excellent in handling properties at the time of commercialization or actual use.

  According to the present invention, a half-fold or three-fold continuous form sheet that is provided with an adhesive layer that has printability on one side or both sides and that does not impair handling handling properties is bonded while carrying a concealment postcard, confidential When processing into products such as postcards, sealed letters, etc., it is effective to continuously supply the processing paper to the sealer and bond it to the product without damaging the workability of the sealer's crimping, bonding, and conveyance. The present invention provides a pressure-bonding re-peelable pressure-sensitive adhesive composition for bonding, which is excellent in “sealer processability” which is made into a bonded product.

That is, the pressure-sensitive adhesive composition provided by the present invention is:
(1) 90 to 98.95 parts by weight of an alkyl group (meth) acrylic acid alkyl ester (a) having 1 to 12 carbon atoms;
(2) 1 to 5 parts by weight of the carboxyl group-containing monomer (b);
(3) (meth) acrylic acid ester system emulsion-polymerized with 0.05 to 5 parts by weight of monomer (c) having any functional group selected from epoxy group, hydroxyl group, silanol group and methylol group In the emulsion, the gel fraction is in the range of 60 to 90% and the adhesive main component (A) is 0.5% of the phosphate ester surfactant (B) per 100 parts by weight of the dry matter basis. It is a pressure-sensitive re-peelable pressure-sensitive adhesive composition containing ˜5 parts by weight and 40 to 300 parts by weight of filler (C) in which organic and inorganic fine powders are combined.

  Further, according to the present invention, the pressure-removable pressure-sensitive adhesive composition according to the present invention is applied as a printing layer with a pressure-sensitive adhesive layer on one or both sides of a bi-fold or tri-fold continuous form paper. Provided is a concealment postcard or a sealed letter characterized by being provided in a thickness range of 1 to 50 μm.

  As described above, the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to the present invention thus provided can be temporarily bonded and bonded under a predetermined pressure and can be re-peeled as appropriate. It is. Moreover, it is a pressure-sensitive adhesive re-peelable pressure-sensitive adhesive that is optimal for use as a pressure-sensitive adhesive for bonding, which requires a pressure-sensitive adhesive function that is resistant to adhesion and contamination. . As an application of the pressure-sensitive adhesive having such a specification as a necessary condition, the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition of the present invention can be used, for example, as a concealing postcard, a confidential postcard, or a pressure-sensitive adhesive layer for sealing a sealed letter. It can be used suitably.

  Moreover, the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to the present invention is used as a pressure-sensitive adhesive for such a bonded product, and is bonded through a sealer rotary roller when commercialized by bonding. Since the bi-fold or tri-fold continuous form paper provided with the agent layer is not disturbed at all by the processing workability to be commercialized while being conveyed under pressure bonding, it can be efficiently made into a bonded product.

  Furthermore, the pressure-sensitive adhesive layer according to the present invention provided on the paper is provided with, for example, an ink jet printer or a normal printing method so that good printing and printing can be performed. The layer can be provided with a pressure-sensitive adhesive layer having printability as a print layer for describing address information and concealment surface concealment information.

  The pressure-sensitive adhesive and re-peelable pressure-sensitive adhesive composition (A) provided by the present invention that fulfills such specifications and functions is a (meth) acrylate emulsion and has a gel content. The resinous component having a rate in the range of 60 to 90% is used as the main adhesive component of the adhesive layer. Furthermore, it contains a filler in which a phosphate ester-based surfactant, an organic fine powder such as starch, and an inorganic fine powder such as an oil-absorbing porous silica powder are combined. In particular, even if the pressure-sensitive adhesive layer surfaces provided on the support surface during actual use are bonded to each other, the anti-blocking property that does not impair each other's re-peelability is exhibited at the time of re-peeling. Also, in connection with this blocking resistance, the pressure-sensitive adhesive layer according to the present invention is bonded and bonded under pressure bonding, and re-peeled. Exhibits anti-fouling resistance.

  In the present invention, a bi-fold or tri-fold continuous form sheet obtained by applying an adhesive having such a composition on one or both sides is continuously supplied to a rotating roller of a sealer, and is pressed between rotating rolls. -A series of crimping / bonding / conveying processes that convey continuous form paper while bonding are carried out as a bonded product extremely efficiently without impeding the workability of the process.

  Therefore, the re-peelable pressure-sensitive adhesive composition according to the present invention provided as an adhesive layer on such continuous form paper does not hinder a series of work workability for pressure bonding / bonding / conveying of the sealer, and the efficiency of bonding product production Therefore, in the present invention, due to the adhesive property of the adhesive layer provided on the paper, the workability that the sealer should perform is influenced. It can be evaluated that the combined pressure-sensitive adhesive layer sufficiently exhibits “sealer processability” defined in Examples described later.

  That is, the pressure-removable pressure-sensitive adhesive composition having excellent “sealer processability” according to the present invention comprises at least a processing support sheet provided as an adhesive layer on one side or both sides of the continuous form sheet. It is used as a pressure-sensitive adhesive layer that is made into a bonded product with high efficiency while being continuously supplied to and bonded and transported.

  Below, it is the best to implement a pressure-removable pressure-sensitive adhesive composition having printability and excellent “sealer processability” used for laminating and conveying a bi-fold or tri-fold continuous form paper according to the present invention. The embodiment will be further described.

  As already mentioned above, the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to the present invention is a concealed postcard or a double-fold or tri-fold continuous form sheet provided as a pressure-sensitive adhesive layer on one or both sides. A pressure-sensitive adhesive composition characterized in that when a sealed letter is processed into a product, the workability related to a sealer, which is a rotary roller for carrying out a work process of conveying and bonding, is effectively carried out without deteriorating. That is, when a continuous form paper provided with such an adhesive layer is continuously supplied to a sealer part of a rotary roller and is made to a bonded product while being pressure-bonded and conveyed by this sealer, an effective workability is exhibited. It was possible to provide a pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition excellent in so-called “sealer processability”.

  Therefore, the pressure-bonding / removable pressure-sensitive adhesive composition having excellent “sealer processability” according to the present invention described above has the following composition.

  The composition and characteristics of the main component (A) of the pressure sensitive adhesive are important in that the gel fraction is in the range of 60 to 90% from the viewpoint of easy peeling under a natural environment of any temperature and humidity. Can be suitably used preferably as a (meth) acrylic acid ester emulsion having a gel fraction of 70% or more.

  In the present invention, the main component of the pressure-sensitive adhesive having such gel fraction characteristics is (1) (meth) acrylic acid alkyl ester having 1 to 12 carbon atoms in the alkyl group described below, preferably an alkyl group. (Meth) acrylic acid alkyl ester (a) having 1 to 4 carbon atoms, (2) a carboxyl group-containing monomer (b), and (3) any one selected from an epoxy group, a hydroxyl group, a silanol group, and a methylol group An acrylic emulsion prepared by a conventional emulsion polymerization method conventionally known using the monomer (c) having the above functional group is suitably used.

Examples of (1) (meth) acrylic acid alkyl ester (a) used in the present invention include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and isopropyl (meth) acrylate. , Butyl (meth) acrylate, isobutyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid Lauryl, nonyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate,
The carbon number is the carbon number of an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an isobutyl group, an isoamyl group, a hexyl group, a heptyl group, an isooctyl group, an isononyl group, or an isodecyl group. .

  In this invention, these single or 2 or more types of (meth) acrylic-acid alkylester (a) is used suitably. Among them, although it is not necessarily limited, in the present invention, for example, from the viewpoint of initial adhesiveness and removability, an alkyl group (meth) acrylic acid alkyl ester having a carbon number of 4 or less (a) In particular, it is more preferable that BA is a main component and EA and / or MMA subcomponents are mixed components. Further, these (meth) acrylic acid esters (a) are used in the range of 90 to 98.95 parts by weight, and (meth) acrylic acid ester emulsions obtained by emulsion polymerization when used outside this range, The initial adhesiveness tends to be insufficient due to the tackiness, and the adhesiveness becomes poor particularly in a high humidity environment, which is not preferable.

  Examples of the carboxyl group-containing monomer (b) used in the present invention (2) include (meth) acrylic acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, maleic acid, fumaric acid, norbornene dicarboxylic acid. Mention may be made of maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, aminoethyl methacrylate, aminopropyl methacrylate and the like as acids and derivatives thereof. These carboxyl group-containing monomers (b) are suitably used suitably in the range of 1 to 5 parts by weight. If the amount is outside this range, the acrylate emulsion type resin obtained by emulsion polymerization is not preferred because of poor adhesion.

  Among the monomers (c) having any functional group selected from the epoxy group, hydroxyl group, silanol group and methylol group (3) used in the present invention, examples of the epoxy group-containing monomer include glycidyl (meth). Acrylate, 3,4-epoxy-1-butene, 3,4-epoxy-3-methyl-1-butene, 3,4-epoxy-1-pentene, 3,4-epoxy-3-methyl-1-pentene, Mention may be made of epoxy group-containing monomers such as 5,6-epoxy-1-hexene and vinylcyclohexene monoxide.

  Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, chloro-2-hydroxypropyl acrylate, and diethylene glycol mono (Meth) acrylate, 1,1,1-trihydroxymethylethane triacrylate, 1,1,1-trishydroxymethylmethylethane triacrylate, 1,1,1-trishydroxymethylpropane triacrylate, hydroxy vinyl ether, hydroxypropyl Examples thereof include hydroxyalkyl vinyl ethers such as vinyl ether and hydroxybutyl vinyl ether.

Examples of the silanol group-containing monomer include silane compounds such as alkoxysilane, acyloxysilane, silane coupling agent, and silylating agent. Alkoxysilanes include Si (OMe) ₄ , MeSi (OMe) ₃ , Me ₂ Si (OMe) ₂ , Me ₃ Si (OMe), C ₂ H ₅ Si (OMe) ₃ , n-C ₃ H ₇ Si ( _{OMe) 3, n-C 6} H 13 Si (OMe) 3, n-C 10 H 21 Si (OMe) 3, CH 2 = CHSi (OMe) 3, C 6 H 5 Si (OMe) 3, (C 6 H ₅ ) ₂ Si (OMe) ₂ , and silane coupling agents include NH ₂ CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ MeSi (OMe) ₃ , NH ₂ CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ SiMe (OMe) ₂ , HSCH ₂ CH ₂ CH ₂ Si (OMe) ₃ , C ₆ H ₅ NHCH ₂ CH ₂ CH ₂ Si (OMe) ₃ , CH ₂ = (CH ₃ ) CCOOCH ₂ CH ₂ CH ₂ Si (OMe) _{3, also, Si (OEt) 4, MeSi} (OEt) 3, _{e 2 Si (OEt) 2,} Me 3 SiOEt and the like, As the _{acyloxysilane, MeSi (OCOCH 3) 3,} C 2 H 5 Si (OMe) 3, CH 2 = CHSi (OCOCH 3) 3 Etc.
Furthermore, examples of the methylol group-containing monomer include N-methylol acrylamide and N-methylol methacrylamide.

  Further, about 0 to 10 parts by weight of other monomers may be copolymerized with respect to 100 parts by weight of the monomers (1) to (3). Other monomers include phenyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxy (meth) acrylate (Meth) acrylic acid alkoxyesters such as propyl; dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate; (meth) acrylamides; (meth) acrylamides such as N-methylol (meth) acrylamide and diacetone acrylamide Ethylene glycol diacrylate, diethyl glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol It can be mentioned diacrylate esters Lumpur, such as diacrylate esters of tripropylene glycol (poly) diacrylate esters of alkylene glycols, and the like.

  Therefore, in the present invention, the monomer (c) having any functional group selected from the epoxy group, hydroxyl group, silanol group and methylol group of (3) is suitably suitable in the range of 0.05 to 5 parts by weight. Can be used for emulsion polymerization. In addition, these copolymerizable monomers (c) are conventionally obtained by emulsion polymerization, which is the main component of the pressure-sensitive adhesive, in the present invention. ) Since the effect of increasing the cohesive force by adjusting the degree of crosslinking of the acrylate emulsion and exerting the effect of balancing the cohesive force, the addition amount is outside the range of 0.05 to 5 parts by weight. The amount used is not preferable from the viewpoint of sufficiently adjusting the degree of crosslinking to improve and balance the cohesive force.

  From the above, in the present invention, by using the (meth) acrylic ester emulsion prepared in this way as the main component of the pressure-sensitive adhesive (A), it is possible to restore the pressure-bonding property excellent in “sealer processability” provided by the present invention. As already described above, the release-type pressure-sensitive adhesive composition has 0 phosphoric ester surfactant (B) per 100 parts by weight of the pressure-sensitive adhesive main component (A) having a gel fraction in the range of 60 to 90%. In the range of 5 to 5 parts by weight, preferably 1 to 2 parts by weight is appropriately contained.

  Examples of the phosphate ester-based surfactant (B) include alkyl polyoxyethylene phosphate alkylphenol polyoxyethylene phosphate, alkyl polyoxyethylene phosphate, alkylphenol polyoxyethylene phosphate, and the like. Or 2 or more types can be mixed and used. In the present invention, when the lower limit value is less than 0.5, the adhesive strength with time of the pressure-sensitive adhesive layer increases, and re-peelability is inhibited. On the other hand, when the upper limit value of 5 is exceeded, the adhesiveness tends to be lowered and inhibited. Further, it tends to contaminate the adherend surface after re-peeling, and neither is preferable.

  Furthermore, the pressure-removable pressure-sensitive adhesive composition according to the present invention has 40 to 300 parts by weight of a filler (C) combined with organic and inorganic fine powders, depending on the purpose of bonding. The pressure-sensitive adhesive composition preferably contains 70 to 250 parts by weight, more preferably 100 to 200 parts by weight.

  The combined filler (C) of organic and inorganic fine powder which is a non-adhesive component in the coating adhesive layer by this adhesive composition is added as a combined filler (C) of organic and inorganic fine powder. Has been. In the present invention, the organic fine powder has a relatively irregular particle shape, irregular particle surface, and an average particle diameter of 5 to 40 μm from the viewpoint of adjusting adhesive force and improving blocking resistance. Tangible fillers in the range are used. Examples thereof include starch powders such as styrene resin powder, acrylic resin powder, cellulose powder, sweet potato, potato, wheat, corn, rice and tapioca. Among them, in the present invention, since the main component of the pressure-sensitive adhesive in the pressure-sensitive adhesive layer is compatible with an aqueous emulsion by emulsion polymerization and is inexpensive, starch powder can be suitably used as appropriate.

  Further, since the pressure-sensitive adhesive composition layer of the present invention is also a printing surface pressure-sensitive adhesive layer as a printing surface, in the present invention, in particular, the anti-blocking property, printing ink acceptability, printability, etc. are balanced or improved. From the viewpoint, an inorganic fine powder having an oil absorption measured according to the boiled linseed oil method of JISK5101 of 100 ml / 100 g or more, preferably 150 ml / 100 g or more is suitably used. For example, charcoal cal, charcoal mug, barium sulfate, satin white, synthetic calcium silicate, synthetic magnesium silicate, synthetic smectite, silica, aluminum hydroxide, synthetic mica, synthetic mica, orastite, nepheline site, talc, kaolin, Examples include diatomaceous earth. In the present invention, an oil-absorbing, porous amorphous silica having an average particle diameter of 1 to 20 μm, preferably 3 to 10 μm, is suitably used as appropriate, but the balance of blocking resistance and printability are suitable. From the viewpoint of improving the printing surface and imparting smoothness to the printed surface, if necessary, the silica powder is mixed with one or more of talc, kaolin, charcoal cal, nepheline site, satin white, synthetic smectite, etc. Inorganic fine powders can be used as appropriate.

  In the present invention, the combination filler (C) of organic and inorganic fine powders is not necessarily limited by the type of the combination powder, particularly for the reasons described above. For example, the combination filler of starch and silica powder is used. Among the agents (C), it is preferable that the silica powder is 10 to 90% in terms of% by weight.

  Further, if necessary, the pressure-sensitive adhesive composition according to the present invention is a compounding agent known per se, for example, a plasticizer, a lubricant, a film-forming aid, within a range that does not impair the effect as the pressure-sensitive adhesive property of the present invention. An antifoaming agent, a thickener, an antistatic agent, an ultraviolet absorber, an antibacterial / antifungal agent, a dye, a pigment, and the like can be appropriately blended. These additives may be blended individually, or two or more may be combined and blended. The amount added depends on the type of additive, but is usually suitably 0.01 to 40 parts by weight, preferably 20 parts by weight or less, more preferably 10 parts by weight or less per 100 parts by weight of the pressure-sensitive adhesive composition. Can be added.

The pressure-removable pressure-sensitive adhesive composition according to the present invention prepared in this way is applied to various adherends at a tensile speed of 10-20 kg / cm ² after bonding with a tensilon-type tensile tester. The T-type peeling speed at 100 mm / min has a pressure-bonding property with an initial adhesive strength (or temporary bonding adhesive strength) of 10 to 60 g / 25 mm. In addition, it can be re-peeled as appropriate after bonding and bonding, and the adhesive strength is almost unchanged even over a long period of time, and the re-peeling force is 60 g / 25 mm or less, preferably 40 g / 25 mm or less. Has removability. Examples of the paper support suitably used in the present invention include, for example, synthetic paper, coated paper, laminated paper, high-quality paper, metallized paper, coated paper for printing, coated paper for recording, and the like. it can.

The application amount of the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to the present invention is usually a basis weight of 3 to 40 g / m ² (dry matter weight), and if the lower limit value is less than 3, the adhesiveness is not sufficiently exhibited. If the upper limit value 40 is exceeded, the adhesive force is too high and re-peeling becomes difficult, and the continuous form paper as the support is torn. In addition, the application of the pressure-sensitive adhesive composition to the paper support is performed by using a conventionally known coating machine or printing machine such as an air knife coater, a blade coater, a bar coater, screen printing, flexographic printing, or a gravure printing machine. It can apply | coat as an agent layer.

  In addition, the pressure-removable pressure-sensitive adhesive composition according to the present invention can be suitably provided as a pressure-sensitive adhesive layer for concealment postcards, confidential postcards, and sealed letters on bi-fold or tri-fold continuous forms. However, as already described above, the pressure-sensitive adhesive layer provided for such use is a bonding adhesive layer provided on a bi-fold or tri-fold continuous form paper, and at the same time, this pressure-sensitive adhesive layer is used for address printing layer, concealment information printing. Since it is a layer, in the present invention, as a concealing postcard, a confidential postcard, or a sealed letter, this pressure-removable pressure-sensitive adhesive composition is preferably used so that the coating film thickness is in the range of 1 to 50 μm. Can be appropriately applied in the range of 1 to 10 μm. In the present invention, when the lower limit value is less than 1 μm, it is difficult to impart good printability to the pressure-sensitive adhesive layer, and when the upper limit value exceeds 50 μm, the anti-blocking property is lowered as a bonding adhesive surface, and the surface smoothness as a printing surface It tends to decrease the sex.

  EXAMPLES The present invention will be further described below with reference to examples, but the present invention is not limited to these examples.

(Example)
In the present invention, using the evaluation method of “sealer workability” defined as follows, (b) the adhesiveness after 5-20 kg / cm ² pressure bonding was measured at a tensile speed of 100 mm / min with a Tensilon type tensile tester. It has a pressure-bonding property with an initial adhesive force (or temporary bonding adhesive force) of 0 to 60 g / 25 mm in T-type peeling force, and (b) the adhesive force is almost unchanged even after a long period of time after the bonding pressure bonding, The “sealer processability” performed by the pressure-removable pressure-sensitive adhesive composition (removable pressure-sensitive adhesive-1 to re-peelable pressure-sensitive adhesive-9) according to the present invention having a re-peeling force of 60 g / 25 mm or less was evaluated.
Nine types of pressure-sensitive releasable pressure-sensitive adhesive compositions according to the present invention (hereinafter simply referred to as re-peelable pressure-sensitive adhesives) prepared as follows using a comma coater on one side (both sides of a part) of a high-quality paper support. Are coated into coated paper having a coating weight of 6.2, 6.3, 6.5 (g / m ² ) basis weight after drying.

(I) <Initial adhesive strength>
The adhesive-coated surfaces of the evaluation paper support are aligned and bonded by applying a linear pressure of 500 kg / cm between a stainless steel and a stainless steel roll nip, and this is cut to a width of 25 mm and a length of 170 mm, and in an atmosphere of 20 ° C. and RH 65%. The T-type peel rate at a tensile rate of 100 mm / min was measured with a Tensilon type tensile tester.
(B) <Peeling feeling>
After the evaluation paper support was bonded in accordance with (A), it was evaluated as follows with the touch peeled by hand. ◎: Peel off smoothly. Δ: Slightly lacking in smoothness X mark: There is no smoothness.
(C) <Blocking resistance>
The surfaces coated with the pressure-sensitive adhesive were overlapped, and a pressure of 500 g / cm ² was applied. After leaving at a relative humidity of 85% and 50 ° C. × 1 hr, the state of the peeled surface was visually observed and evaluated. As a result, peeling was not easily felt, and the paper support surface was not damaged and marked as ◎ without blocking, and the surface was scratched and fluffy pulp fibers were marked as x .
(D) <Evaluation of “sealer processability”>
Using the re-peelable pressure-sensitive adhesive composition according to the present invention, a pressure-sensitive adhesive layer provided on one or both sides of a paper support, which is a bi-fold or tri-fold continuous form paper such as a concealment postcard or a confidential postcard, By satisfying the “adhesive layer characteristics” of (ii) initial peel strength, (ii) feeling of peeling, and (iii) anti-blocking properties, when used in such applications, pressure-bonding / bonding with a rotating roller of a sealer It does not reduce (or inhibit) the bonding product efficiency, which is a series of processing workability to be conveyed.
Accordingly, the pressure-sensitive adhesive layer provided on the paper support in such applications is processed by pressure bonding / bonding / conveyance to be achieved by the sealer due to the “pressure-sensitive adhesive layer characteristics” (i) to (c) above. Workability is affected. From the fact that these were carried out, in the present invention, the bonding adhesive layer having such printing / printing property, pressure bonding property, and removability is the rotation roller for pressure bonding / bonding / conveyance. It can be evaluated that “sealer workability” is exhibited.

From the above, the pressure-removable pressure-sensitive adhesive composition according to the present invention impairs “sealer processability” with respect to the processing operation of “crimping / bonding / conveying” of continuous form paper performed by the rotating roller of the sealer (or It is important to clear at least the following factors (a) to (c).
(A) (a) The pressure-sensitive adhesive layer provided on the paper support according to the present invention that exhibits the initial adhesive force is completely adhered to the rotating roller surface of the sealer at the time of pressure contact, which is a processing step by the sealer. Or, it does not cause adhesion contamination, and does not deteriorate the transportability of the paper support by the rotating roller.
(B) The initial adhesive force (a) is expressed under the pressure of 500 kg / cm of linear pressure between the rotating rollers of the sealer and achieves the peeling feeling (b).
(C) The coating pressure-sensitive adhesive layer satisfying (a) and (b) expressed under a pressure of 500 kg / cm between the rotating rollers of the sealer achieves the blocking resistance (c).

The pressure-sensitive adhesive and re-peelable pressure-sensitive adhesive composition provided by the present invention has a (meth) acrylic ester emulsion as the main component of the pressure-sensitive adhesive and a gel fraction in the range of 60 to 90%. And a filler comprising a combination of an organic fine powder such as starch and an inorganic fine powder such as an oil-absorbing porous silica powder.
<Removable adhesive-1>
The carbon number of the alkyl group of 74.5 parts by weight of the main component BA and 20 parts by weight of the subcomponent EA is 1
94.5 parts by weight of -4 (meth) acrylic acid ester (a), 3 parts by weight of carboxyl group-containing monomer (b) of acrylic acid, and a functional group monomer (c) whose functional group is an epoxy group ) Was subjected to emulsion polymerization to prepare a (meth) acrylic acid ester emulsion having a gel fraction of 83%, and this was used as the pressure-sensitive adhesive main component (A).
Next, 2 parts by weight of a polyoxyethylene alkyl phosphate ester (hereinafter abbreviated as POEAPE) phosphate ester-based surfactant (B) per 100 parts by weight of the adhesive main component (A), Composed of 200 parts by weight of filler (C) in combination with 100 parts by weight of starch and 100 parts by weight of silica powder having an oil absorption of 230 (ml / 100 g) obtained in accordance with the boiled linseed oil method of JISK5101 A pressure-sensitive re-peelable pressure-sensitive adhesive composition according to the present invention was prepared. This re-peelable pressure-sensitive adhesive-1 was applied to one surface of a high-quality paper with a coating amount of 6.2 (g / m ² ) basis weight with a coating film of 3 μm.

  Next, about 20cm x 45cm coated paper provided with a pressure-sensitive adhesive layer on one side, it was printed on the pressure-sensitive adhesive coated surface with a foam printer, and then printed with a commercially available BJ inkjet printer manufactured by Canon. As a result, the dot density was high, the color was vivid, there was no ink bleeding such as bubbling or feathering, the printing quality was good, and the printing support of the paper support was smooth and good. Also, the adhesive property of this coated paper is good adhesion under pressure bonding, the peel feeling is also marked with ◎, and the blocking resistance of ◎ is demonstrated, as a result, re-peelability Adhesive-1 was able to exhibit good “sealer processability”.

<Removable adhesive-2>
74 parts by weight of the main component BA and 20 parts by weight of the subcomponent EA, 94 parts by weight of the (meth) acrylic acid ester (a) having 1 to 4 carbon atoms, and a carboxyl group-containing monomer of acrylic acid Emulsion polymerization is carried out using 4.5 parts by weight of (b) and 1.5 parts by weight of the functional group monomer (c) N-methylolacylamide whose functional group is a methylol group, and the gel fraction is An 80% (meth) acrylic acid ester emulsion was prepared and used as the pressure-sensitive adhesive main component (A). Next, 4 parts by weight of POEAPE phosphate ester surfactant (B), 100 parts by weight of starch, and oil absorption 230 (ml / 100 g) per 100 parts by weight of this adhesive main component (A) A pressure-sensitive adhesive releasable pressure-sensitive adhesive composition according to the present invention comprising 200 parts by weight of a filler (C) in which 50 parts by weight of silica powder and 50 parts by weight of talc are combined with organic and inorganic fine powders. Was prepared. This re-peelable pressure-sensitive adhesive-2 was applied to one surface of a high-quality paper with a coating weight of 6.2 (g / m ² ) basis weight and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side was prepared in the same manner as the releasable pressure-sensitive adhesive-1, and exhibited good printing and printability, no ink bleeding, and print quality. Was good. Also, the adhesive property of this coated paper is good adhesion under pressure bonding, the peel feeling is also marked with ◎, and the blocking resistance of ◎ is demonstrated, as a result, re-peelability Adhesive-2 was able to exhibit good “sealer processability”.

<Removable adhesive-3>
The alkyl group consisting of 76.5 parts by weight of the main component BA, 15 parts by weight of the sub-component EA, and 5 parts by weight of MMA has an alkyl group of 1 to 4 carbon atoms of (meth) acrylic acid ester (a) of 96. 5 parts by weight, 3.0 parts by weight of a carboxyl group-containing monomer (b) of acrylic acid, and 0.5 parts by weight of a functional group monomer (c) of γ-methacryloxypropyltrimethoxysilane whose functional group is a silanol group And (meth) acrylic acid ester emulsion having a gel fraction of 85 was prepared, and this was used as the main component of the pressure-sensitive adhesive (A). Next, 4 parts by weight of POEAPE phosphate ester surfactant (B), 100 parts by weight of starch and oil absorption 180 (ml / 100 g) per 100 parts by weight of the main component of the adhesive (A) A pressure-bondable re-peelable pressure-sensitive adhesive composition according to the present invention comprising 160 parts by weight of filler (C) in which 50 parts by weight of silica powder and 10 parts by weight of talc were combined was prepared. This re-peelable pressure-sensitive adhesive-3 was applied to one surface of a high-quality paper with a coating weight of 6.2 (g / m ² ) basis weight and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with an adhesive layer on one side or partially on both sides was prepared in the same manner as the releasable adhesive-1, and exhibited good printing and printability. There was no bleeding and the print quality was good. In addition, the adhesive property of this coated paper under pressure bonding, which is a characteristic of the adhesive layer, is also good, especially when both sides are coated, the feeling of peeling is also marked with ◎, and the blocking resistance of ◎ marks Was demonstrated. As a result, the re-peelable pressure-sensitive adhesive-3 was able to exhibit good “sealer processability”.

<Removable adhesive-4>
97 weight parts of (meth) acrylic acid ester (a) having 1 to 4 carbon atoms in the alkyl group consisting of 76.9 parts by weight of main component BA, 15 parts by weight of subcomponent EA, and 5 parts by weight of MMA Part, 3.0 parts by weight of the carboxyl group-containing monomer (b) of acrylic acid, and 0.1 parts by weight of the functional group monomer (c) GMA whose functional group is an epoxy group. A (meth) acrylic acid ester emulsion having a gel fraction of 75% was prepared and used as the main component of the pressure-sensitive adhesive (A). Then, per 100 parts by weight of the main component of the pressure-sensitive adhesive (A), 1.6 parts by weight of POEAPE phosphate ester surfactant (B), 50 parts by weight of starch, and oil absorption 180 (ml / 100 g) The pressure-bondable re-peelable pressure-sensitive adhesive composition according to the present invention was prepared, comprising 110 parts by weight of filler (C) in which 50 parts by weight of silica powder and 10 parts by weight of talc were combined. This re-peelable pressure-sensitive adhesive-4 was applied to one surface of a high-quality paper with a coating weight of 6.3 (g / m ² ) and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side exhibits good printing and printability as in the case of the releasable pressure-sensitive adhesive-1, and there is no ink bleeding and print quality. It was good. Further, the adhesive property of this coated paper under pressure bonding, which is a pressure-sensitive adhesive layer property, was good, the feeling of peeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-4 was able to exhibit good “sealer processability”.

<Removable adhesive-5>
96 parts by weight of (meth) acrylic acid ester (a) having 2 or 4 carbon atoms in the alkyl group consisting of 86 parts by weight of main component BA and 10 parts by weight of subcomponent MMA, and carboxyl group of acrylic acid 3.0 parts by weight of the monomer (b), 0.5 parts by weight of the functional group monomer (c) composed of 2-hydroxyethyl methacrylate whose functional group is a hydroxyl group, and N-MAM whose functional group is a methylol group Emulsion polymerization is performed using 0.5 part by weight of the functional group monomer (c) to prepare a (meth) acrylic acid ester emulsion having a gel fraction of 62%. ). Next, per 100 parts by weight of the pressure-sensitive adhesive main component (A), 1 part by weight of POEAPE phosphate surfactant (B), 100 parts by weight of starch, and oil absorption 180 (ml / 100 g) A pressure-bondable re-peelable pressure-sensitive adhesive composition according to the present invention comprising 230 parts by weight of a filler (C) obtained by combining 100 parts by weight of silica powder and 30 parts by weight of talc was prepared. This re-peelable pressure-sensitive adhesive-5 was applied to one surface of a high-quality paper with a coating weight of 6.3 (g / m ² ) and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side exhibits good printing and printability as in the case of the releasable pressure-sensitive adhesive-1, and there is no ink bleeding and print quality. It was good. Further, the adhesive property of this coated paper under pressure bonding, which is a pressure-sensitive adhesive layer property, was good, the feeling of peeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-5 was able to exhibit good “sealer processability”.

<Removable adhesive-6>
97 parts by weight of (meth) acrylic acid ester (a) having 2 or 4 carbon atoms in the alkyl group, consisting of 81.9 parts by weight of main component BA and 15 parts by weight of subcomponent EA, and carboxyl of acrylic acid The gel fraction is obtained by emulsion polymerization using 3.0 parts by weight of the group-containing monomer (b) and 0.1 parts by weight of the functional monomer (c) composed of trimethoxysilyl acrylate whose functional group is a silanol group. A (meth) acrylic acid ester emulsion having a ratio of 75% was prepared and used as the main component (A) of the pressure-sensitive adhesive. Next, per 100 parts by weight of the pressure-sensitive adhesive main component (A), 1.2 parts by weight of POEAPE phosphate ester surfactant (B), 50 parts by weight of starch, and oil absorption 180 (ml / 100 g) The pressure-removable pressure-sensitive adhesive composition according to the present invention comprising 100 parts by weight of the filler (C) in combination with 50 parts by weight of silica powder was prepared. This re-peelable pressure-sensitive adhesive-6 was applied to one surface of a high-quality paper with a coating weight of 6.5 (g / m ² ) and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side exhibits good printing and printability as in the case of the releasable pressure-sensitive adhesive-1, and there is no ink bleeding and print quality. It was good. Further, the adhesive property of this coated paper under pressure bonding, which is a pressure-sensitive adhesive layer property, was good, the feeling of peeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-6 was able to exhibit good “sealer processability”.

<Removable adhesive-7>
97 parts by weight of (meth) acrylic acid ester (a) of 78.9 parts by weight of the main component BA, 15 parts by weight of EA, and 3 parts by weight of lauryl methacrylate having 12 alkyl groups, Using 3.0 parts by weight of the carboxyl group-containing monomer (b) of acrylic acid and 0.1 parts by weight of the functional group monomer (c) of GMA whose functional group is an epoxy group, emulsion polymerization is performed to obtain a gel fraction. A (meth) acrylic acid ester emulsion having a rate of 70% was prepared and used as the pressure-sensitive adhesive main component (A). Next, per 100 parts by weight of the main component of the pressure-sensitive adhesive (A), 1.2 parts by weight of the phosphoric ester surfactant (B) as POEAPE, 100 parts by weight of starch, and an oil absorption of 230 (ml / 100 g) The pressure-bondable re-peelable pressure-sensitive adhesive composition according to the present invention comprising 200 parts by weight of filler (C) in combination with 100 parts by weight of silica powder was prepared. This re-peelable pressure-sensitive adhesive-7 was applied to one surface of a high-quality paper with a coating weight of 6.5 (g / m ² ) and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side exhibits good printing and printability as in the case of the releasable pressure-sensitive adhesive-1, and there is no ink bleeding and print quality. It was good. Further, the adhesive property of this coated paper under pressure bonding, which is a pressure-sensitive adhesive layer property, was good, the feeling of peeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-7 was able to exhibit good “sealer processability”.

<Removable adhesive-8>
96.9 parts by weight of (meth) acrylic acid ester (a) from 79.9 parts by weight of the main component BA, 14 parts by weight of EA and 3 parts by weight of lauryl methacrylate having 12 alkyl groups 1 part by weight, 3 parts by weight of a carboxyl group-containing monomer (b) of acrylic acid, and 0.1 part by weight of a functional group monomer (c) made of trimethoxysilyl acrylate whose functional group is a silanol group Then, a (meth) acrylic acid ester emulsion having a gel fraction of 72% was prepared and used as the pressure-sensitive adhesive main component (A). Next, per 100 parts by weight of this adhesive main component (A), 1 part by weight of POEAPE phosphate ester surfactant (B), 100 parts by weight of starch, and oil absorption 230 (ml / 100 g) A pressure-bonding removable adhesive composition according to the present invention comprising 200 parts by weight of a filler (C) combined with 100 parts by weight of silica powder was prepared. This releasable pressure-sensitive adhesive-8 was applied to one surface of a high-quality paper with a coating weight of 6.3 (g / m ² ) basis weight and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side, as well as the releasable pressure-sensitive adhesive-1, exhibits good printing and printability, has no ink bleeding, and has a printing quality. It was good. Further, the adhesive property of the coated paper under pressure bonding, which is the pressure-sensitive adhesive layer property, was good, the peel feeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-8 was able to exhibit good “sealer processability”.

<Removable adhesive-9>
97 parts by weight of (meth) acrylic acid ester (a), 72 parts by weight of main component BA, 15 parts by weight of EA, 10 parts by weight of 2-ethylhexyl acrylate having an alkyl group of 8 carbon atoms, acrylic acid And 2.9 parts by weight of the carboxyl group-containing monomer (b) and 0.1 part by weight of the functional group monomer (c) GMA whose functional group is an epoxy group, and the gel fraction is A 80% (meth) acrylic acid ester emulsion was prepared and used as the main component of the pressure-sensitive adhesive (A). Next, 1 part by weight of POEAPE phosphate ester surfactant (B), 100 parts by weight of starch, and 230 parts by weight of oil absorption (100 ml / 100 g) per 100 parts by weight of the adhesive main component (A). A pressure-bondable re-peelable pressure-sensitive adhesive composition according to the present invention comprising 150 parts by weight of a filler (C) obtained by combining 60 parts by weight of silica powder and 10 parts by weight of talc was prepared. The releasable pressure-sensitive adhesive-9 was applied to one surface of a high-quality paper with a coating weight of 6.2 (g / m ² ) basis weight and a coating film of 2 μm.
Next, the coated paper of 20 cm × 45 cm provided with a pressure-sensitive adhesive layer on one side exhibits good printing and printability as in the case of the releasable pressure-sensitive adhesive-1, and there is no ink bleeding and print quality. It was good. Further, the adhesive property of this coated paper under pressure bonding, which is a pressure-sensitive adhesive layer property, was good, the feeling of peeling was marked with ◎, and the blocking resistance of ◎ was exhibited. As a result, the re-peelable pressure-sensitive adhesive-9 was able to exhibit good “sealer processability”.

(Comparative example)
In order to clarify the relationship with the “sealer processability” of the removable pressure-sensitive adhesive according to the present invention, the gel fraction of the (meth) acrylic acid ester emulsion as the main component of the pressure-sensitive adhesive deviates from the range of 60 to 90%. A releasable pressure-sensitive adhesive-ratio 1 and a re-peelable pressure-sensitive adhesive-ratio 2 made of a resinous component were prepared as comparative examples, and their relationship with "sealer processability" was evaluated.
<Removable adhesive-Ratio 1>
74.5 parts by weight of the main component BA, 20 parts by weight of the subcomponent EA, 94.5 parts by weight of the (meth) acrylic acid ester (a) having 2 or 4 carbon atoms, and acrylic acid Emulsion polymerization is performed using 4 parts by weight of the carboxyl group-containing monomer (b) and 8 parts by weight of the functional group monomer (c) whose functional group is an epoxy group, and the gel fraction is 92% ( A (meth) acrylic ester emulsion was prepared and used as the main component (A) of the pressure-sensitive adhesive.
Next, 2 parts by weight of a polyoxyethylene alkyl phosphate ester (hereinafter abbreviated as POEAPE) phosphate ester-based surfactant (B) per 100 parts by weight of the adhesive main component (A), Composed of 200 parts by weight of filler (C) in combination with 100 parts by weight of starch and 100 parts by weight of silica powder having an oil absorption of 230 (ml / 100 g) obtained in accordance with the boiled linseed oil method of JISK5101 A pressure-sensitive re-peelable pressure-sensitive adhesive composition according to the present invention was prepared. This re-peelable pressure-sensitive adhesive-1 was applied to one surface of fine paper with a coating weight of 6.2 (g / m ² ) basis weight and a coating film of 2 μm.

  Next, about 20cm x 45cm coated paper provided with a pressure-sensitive adhesive layer on one side, it was printed on the pressure-sensitive adhesive coated surface with a foam printer, and then printed with a commercially available BJ inkjet printer manufactured by Canon. As a result, there was no ink bleeding such as padding or feathering, but the color was unclear, the printing quality was poor, and the printing support of the paper support was not smooth. In addition, the adhesiveness under pressure bonding, which is the pressure-sensitive adhesive layer characteristic of the coated paper, was insufficient, particularly the feeling of peeling was not refreshed, and the blocking resistance was also lowered. As a result, the re-peelable pressure-sensitive adhesive ratio 1 could not sufficiently exhibit “sealer processability”.

<Removable adhesive-Ratio 2>
78.0 parts by weight of the main component BA and 20 parts by weight of the subcomponent EA, 98.0 parts by weight of the (meth) acrylic acid ester (a) having 1 to 4 carbon atoms, and acrylic acid Emulsion polymerization is performed using 2 parts by weight of the carboxyl group-containing monomer (b) and 0.2 parts by weight of the chain transfer agent normal dodecyl mercaptan to prepare a (meth) acrylic acid ester emulsion having a gel fraction of 18%. And this was made into the adhesive main component (A).
Next, 2 parts by weight of a polyoxyethylene alkyl phosphate ester (hereinafter abbreviated as POEAPE) phosphate ester-based surfactant (B) per 100 parts by weight of the adhesive main component (A), Composed of 200 parts by weight of filler (C) in combination with 100 parts by weight of starch and 100 parts by weight of silica powder having an oil absorption of 230 (ml / 100 g) obtained in accordance with the boiled linseed oil method of JISK5101 A pressure-sensitive re-peelable pressure-sensitive adhesive composition according to the present invention was prepared. This re-peelable pressure-sensitive adhesive-1 was applied to one surface of fine paper with a coating weight of 6.2 (g / m ² ) basis weight and a coating film of 2 μm.

  Next, about 20cm x 45cm coated paper provided with a pressure-sensitive adhesive layer on one side, it was printed on the pressure-sensitive adhesive coated surface with a foam printer, and then printed with a commercially available BJ inkjet printer manufactured by Canon. As a result, the color was unclear, the printing quality was poor, the printing runnability of the paper support was not smooth, and the paper support was bent. Moreover, the adhesiveness under pressure bonding, which is the pressure-sensitive adhesive layer characteristic of the coated paper, was insufficient, the feeling of peeling was not particularly refreshed, and the blocking resistance was significantly reduced. As a result, it was not possible to process the bonded product with the releasable adhesive-ratio 2.

From the above, the production method is extremely simple, low in cost, processed as a pressure-sensitive adhesive for the support, or (meth) acrylic acid ester emulsion having excellent handling and workability in actual use as the main component of the pressure-sensitive adhesive. A series of pressure-bonding / bonding / carrying under pressure-removable pressure-sensitive adhesive composition according to the present invention, by continuously supplying a bi-fold or tri-fold continuous form paper provided as a pressure-sensitive adhesive layer on one or both sides to a sealer In addition, the coated adhesive layer by the pressure-sensitive adhesive composition of the present invention is highly efficient without reducing the workability related to the rotating roller of the sealer, so that it can be continuously bonded to concealed postcards, confidential postcards and sealed letters. It was possible to provide a pressure-removable pressure-sensitive adhesive composition for pressure-sensitive adhesive layers such as concealment postcards, confidential postcards, and sealed letters, which is excellent in “sealer processability” to be made into a bonded product.

Claims (5)

A double-folded or tri-fold continuous form paper with a pressure-removable and re-peelable pressure-sensitive adhesive layer having printability on one or both sides of a paper support, which has been printed and printed, is used as a sealer. In the pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition that does not impair the workability of the sealer device in order to process it into a concealed bonded product while being continuously supplied to the device and crimped, bonded, and conveyed,
(1) 90 to 98.95 parts by weight of an alkyl group (meth) acrylic acid alkyl ester (a) having 1 to 12 carbon atoms;
(2) 1 to 5 parts by weight of the carboxyl group-containing monomer (b);
(3) 0.05 to 5 parts by weight of the monomer (c) having any functional group selected from an epoxy group, a hydroxyl group, a silanol group, and a methylol group;
(Meth) acrylic ester emulsion obtained by emulsion polymerization using
And per 100 parts by weight of the pressure-sensitive adhesive main component (A) having a gel fraction in the range of 60 to 90%,
0.5 to 5 parts by weight of the phosphate ester surfactant (B);
40 to 300 parts by weight of a combination filler (C) of organic and inorganic fine powders;
A pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition comprising:   The organic fine powder is starch, and the inorganic fine powder is a silica powder having an oil absorption of 100 to 250 ml / 100 g according to a boiled linseed oil method in accordance with the JISK5101 method. The pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition described in 1. In the combination filler (C) of starch and silica powder, the silica powder is expressed as 10% by weight.
The pressure-sensitive adhesive peelable pressure-sensitive adhesive composition according to claim 2, wherein the pressure-sensitive adhesive composition is 90%.   The pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to any one of claims 1 to 3 has a coating film thickness of 1 to 50 µm on the pressure-sensitive adhesive layer provided on one or both sides of the paper support of the continuous form. A concealing postcard characterized by being made to become. The pressure-sensitive adhesive re-peelable pressure-sensitive adhesive composition according to any one of claims 1 to 3 has a coating film thickness of 1 to 50 µm on the pressure-sensitive adhesive layer provided on one or both sides of the paper support of the continuous form. A sealed letter characterized by