JP5296371B2 - Removable adhesive sheet for printing and method for producing the same - Google Patents

Description

  The present invention relates to a re-peelable pressure-sensitive adhesive sheet for printing and a method for producing the same.

  Currently, display materials using inkjet printing that can meet the demands of consumers are widely used in outdoor advertising billboards, signs, vehicle advertisements, and other advertising fields. Plasticized polyvinyl chloride resin films have a special surface treatment. Therefore, it is widely used because it has excellent ink fixing properties.

  The display material is attached to a predetermined adherend for a certain period of time, displayed, peeled off, and then replaced with another new display material. Accordingly, the display material needs to be securely attached to the adherend for a certain period of time, while it must be easily peeled off and removed from the adherend after a certain period of time. An adhesive having a moderate adhesive strength is used for the peelable adhesive sheet.

  As the printing ink used for printing the display material, solvent-based ink is used. Although the solvent-based ink penetrates into the display material and printing on the display material is possible, the solvent in the solvent-based ink Penetrates into the pressure-sensitive adhesive layer and reduces the cohesive force of the pressure-sensitive adhesive layer. As a result, the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer is reduced and the display material is unexpectedly peeled off from the adherend. There has been a problem that an adhesive residue is generated when the material is peeled off from the adherend.

  Therefore, in Patent Document 1, a printing re-peelable pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer and a support having ink receptivity, and a printing having a barrier layer between the pressure-sensitive adhesive layer and the support. A re-peelable pressure-sensitive adhesive sheet has been proposed.

  As the barrier layer of the re-peelable pressure-sensitive adhesive sheet for printing, an aluminum foil is used as in Example 1, and the aluminum foil and the polyvinyl chloride resin sheet are laminated and integrated through an adhesive. Adhesive integration between the foil and the polyvinyl chloride resin sheet is insufficient, and the polyvinyl chloride resin sheet and the aluminum foil are unexpectedly separated when the re-peelable adhesive sheet for printing is peeled off from the adherend. Had a point.

  Furthermore, when aluminum foil is used, there is a problem that when the re-peelable pressure-sensitive adhesive sheet for printing is stretched, the aluminum foil is cracked, or the coloring of the display material is limited due to coloring with the aluminum foil. Had.

  In addition, the re-peelable pressure-sensitive adhesive sheet for printing lacks flexibility because the barrier layer made of metal foil or the like is hard, and even if it is attached to an adherend having a curved surface or a complicated surface shape, Even if the re-peelable pressure-sensitive adhesive sheet for printing cannot be smoothly applied to the surface shape and can be stuck in a state along the surface shape, the re-peelable pressure-sensitive adhesive sheet for printing is covered as time passes. There was a problem that it peeled off from the body.

JP 2003-321657 A

  In the present invention, the adhesive layer is not affected by the solvent contained in the solvent-based ink, and the desired adhesiveness is maintained over a long period of time, and the adherend having a curved surface or a complicated surface shape is used. In addition, the present invention provides a re-peelable pressure-sensitive adhesive sheet for printing that can smoothly follow and be beautifully adhered and can reliably maintain the state for a long period of time.

  The re-peelable pressure-sensitive adhesive sheet for printing according to the present invention is a re-peelable pressure-sensitive adhesive sheet for printing in which a pressure-sensitive adhesive layer is laminated and integrated on one surface of a support sheet, and is between the support sheet and the pressure-sensitive adhesive layer. The intermediate layer is made of a synthetic resin having a glass transition temperature of −50 to 60 ° C. and having an elongation at break of 200 to 500%.

  As the support sheet 1, when printing is performed on the surface of the support sheet 1 using a solvent-based ink by an ink jet printing method or a silk printing method, the solvent-based ink penetrates the support sheet and is fixed without dripping the solvent-based ink. I can do it.

  The ink jet printing method is a printing method in which fine droplets of low-viscosity solvent-based ink are ejected and adhered to the surface layer of a sheet to print images / characters. The solvent-based ink refers to an ink in which a dye or pigment is dissolved or dispersed as a colorant in a solvent. Examples of the solvent constituting the solvent-based ink include methyl ethyl ketone, cellosolve acetate, butanol, isopropyl alcohol, triethylene glycol, toluene, and ethyl acetate.

  Examples of such a support sheet 1 include a synthetic resin sheet that is soluble or swells in a solvent-based ink, and a synthetic resin sheet that is blended with a plasticizer and a porous additive, and has excellent weather resistance. From the above, a polyvinyl chloride resin sheet and an acrylic resin sheet are preferable, a plasticized polyvinyl chloride resin sheet and a plasticized acrylic resin sheet are more preferable, and a plasticized polyvinyl chloride resin sheet is particularly preferable. preferable.

  If the thickness of the support sheet 1 is thin, the absorption performance of the solvent-based ink may be deteriorated. On the other hand, if the thickness is thick, the re-peelable pressure-sensitive adhesive sheet for printing becomes heavy and is easily peeled off from the adherend. Since handleability may fall, 40-120 micrometers is preferable.

  In addition, it does not specifically limit as a formation method of the said support sheet 1, For example, cast molding, calender molding, extrusion molding, inflation molding, etc. are mentioned. Moreover, a plasticizer, an ultraviolet absorber, a light stabilizer, an antioxidant, a pigment, a filler, a porous filler, a flame retardant, and the like may be added to the support sheet 1 as necessary.

  Furthermore, the support sheet 1 may be a colored one or may contain a known pigment. From the viewpoint of color reproducibility of printing when printing on the support sheet 1, it is preferable to add a white pigment such as titanium oxide.

  As shown in FIG. 1, a pressure-sensitive adhesive layer 3 is laminated and integrated on one surface of the support sheet 1 via an intermediate layer 2. That is, the intermediate layer 2 and the pressure-sensitive adhesive layer 3 are laminated and integrated in this order on one surface of the support sheet 1.

  In order to prevent the solvent contained in the solvent-based ink from penetrating into the pressure-sensitive adhesive layer 3 when the support layer 1 is printed using the solvent-based ink, the intermediate layer 2 is formed with the support sheet 1 and the pressure-sensitive adhesive. It is interposed between the layers 3. The intermediate layer 2 may be a single layer or a laminate of a plurality of sheets.

  In order to improve the integrity of the intermediate layer 2 and the pressure-sensitive adhesive layer 3, a primer layer is provided on the surface of the intermediate layer 2 facing the pressure-sensitive adhesive layer 3, or a surface such as corona discharge treatment or plasma discharge treatment is provided. Processing may be performed.

  Thus, the intermediate layer 2 made of a synthetic resin having a glass transition temperature of −50 to 60 ° C. and having a tensile elongation at break of 200 to 500% is interposed between the support sheet 1 and the pressure-sensitive adhesive layer 3. The solvent contained in the solvent-based ink is prevented from penetrating into the pressure-sensitive adhesive layer 3, and the adhesive physical properties of the pressure-sensitive adhesive layer 3 are substantially maintained before and after printing on the support sheet 1.

  Here, if the glass transition temperature of the synthetic resin constituting the intermediate layer is low, the ability to prevent the solvent contained in the solvent-based ink from penetrating into the pressure-sensitive adhesive layer deteriorates in a high-temperature environment outdoors. On the other hand, if it is high, the flexibility of the intermediate layer is lowered, the flexibility of the releasable pressure-sensitive adhesive sheet for printing is lowered, and it becomes difficult to construct a complicated shape or curved surface. -20 to 60 ° C is preferable, and -20 to 50 ° C is more preferable.

  In addition, when the elongation at break of the intermediate layer 2 is low, when the releasable pressure-sensitive adhesive sheet for printing is attached to an adherend, an extension force is applied to the releasable pressure-sensitive adhesive sheet for printing. While cracking occurs and the performance of preventing penetration of the solvent contained in the solvent-based ink into the pressure-sensitive adhesive layer is lowered, even if it is high, the effect does not change, so it is limited to 200 to 500%, preferably 300 to 500%. .

  The glass transition temperature of the synthetic resin constituting the intermediate layer is measured according to JIS K7121, and the tensile elongation at break of the intermediate layer is measured according to JIS K7113. .

  Therefore, during sticking of the printing releasable pressure-sensitive adhesive sheet to the adherend, a float or a gap occurs between the printing releasable pressure-sensitive adhesive sheet and the adherend, or the printing re-peelable pressure-sensitive adhesive sheet is adhered. There is no possibility of peeling off from the body and dropping off, and adhesive residue is generated on the adherend surface even when the re-peelable adhesive sheet for printing is peeled off from the adherend after a predetermined period of time has passed. There is no.

  And since the intermediate | middle layer 2 consists of a synthetic resin whose glass transition temperature is -50-60 degreeC and a tensile breaking elongation is 200-500%, the releasable adhesive sheet for printing is excellent in the softness | flexibility. In addition, it can smoothly follow and adhere to an adherend having a curved surface or a complicated surface shape, and a re-peelable pressure-sensitive adhesive sheet for printing can be applied over time even after sticking. It does not peel off the body and can maintain a beautiful sticking state.

  The synthetic resin constituting the intermediate layer 2 may have a glass transition temperature of −50 to 60 ° C., and was selected from the group consisting of polyester resins, polyurethane resins, silicone resins, and linear aliphatic polyamide resins. It is preferably at least one synthetic resin, and a linear aliphatic polyamide resin is preferred.

  When the synthetic resin constituting the intermediate layer 2 is at least one synthetic resin selected from the group consisting of a polyester resin, a polyurethane resin, a silicone resin, and a linear aliphatic polyamide resin, the carbon number is It is preferable to have 4 to 12 alkylene groups in the main chain. By having an alkylene group having 4 to 12 carbon atoms in the main chain, the flexibility of the intermediate layer is improved, and the releasable pressure-sensitive adhesive sheet for printing is applied to an adherend having a curved surface or a complicated shape. It is because it can be made to stick smoothly.

  Furthermore, the intermediate layer 2 is formed on one side of a support sheet with a paint containing a synthetic resin having at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group, and a hydroxyl group, and a solvent. It is preferably formed by applying and drying.

  Examples of the solvent constituting the paint for forming the intermediate layer 2 include water, methanol, ethanol, alcohols such as 2-propanol, n-butanol, and 2-butanol, and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. , Β-oxyethyl methyl ether (methyl cellosolve), β-oxyethyl ether (ethyl cellosolve), butyl-β-oxyethyl ether (butyl cellosolve), ethylene glycol monoethers such as propylene glycol monomethyl ether (cellosolves) , Aromatic hydrocarbons such as benzene, toluene, xylene, ethyl acetate, butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, propylene glycol mono Chill ether acetate, propylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, and the like esters such as diethylene glycol monobutyl ether acetate.

  Among the above, in order to prevent alteration such as swelling and dissolution of the support sheet at the time of application and shrinkage and deformation of the support sheet at the time of drying, lower carbon number of 1 to 3 such as methyl alcohol, ethyl alcohol, and isopropyl alcohol. By adjusting alcohol as the main solvent, it is possible to prevent alteration of the support sheet due to attack by the solvent and drying heat, and to obtain a beautiful re-peelable pressure-sensitive adhesive sheet for printing.

  When the support sheet is a polyvinyl chloride resin sheet, the support sheet is easily altered by the solvent, but as the alcohol solvent, a lower alcohol having 1 to 3 carbon atoms such as methyl alcohol, ethyl alcohol, isopropyl alcohol or the like was used. By using the coating material, it is possible to more reliably prevent the support sheet from being altered.

  As the synthetic resin, the repeating unit having at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group and a hydroxyl group is preferably 10 mol% or more, more preferably in the molecule. A linear aliphatic polyamide resin containing 20 to 50 mol% is preferable, and such a linear aliphatic polyamide resin dissolves well in a lower alcohol having 1 to 3 carbon atoms while preventing alteration of the support sheet. A uniform intermediate layer can be formed by uniformly applying to one surface of the support sheet.

The repeating unit is preferably a structural formula represented by the following formula 1, more preferably a structural formula represented by the following formula 2, and in the following formula 2, R ³ is a methyl group. Particularly preferred.

R ¹ and R ² in Formula 1 may be different or the same for each repeating unit. R ^{1 to} R ³ in Formula 2 may be different or the same for each repeating unit. R ^{4 in} Formula 3 may be different or the same for each repeating unit.

  That is, the linear aliphatic polyamide resin has a repeating unit having the structural formula shown in Formula 1 and a repeating unit having the structural formula shown in Formula 3, and is shown in Formula 1. Those having a repeating unit having a structural formula of 10 mol% or more, more preferably 20 to 50 mol% in the molecule are preferably used.

（但し、Ｒ¹は炭素数が４〜１２のアルキレン基であり、Ｒ²は炭素数が１〜３のアルキレン基であり、Ｘは、アルコキシ基、カルボキシ基、アミノ基又は水酸基である。）

(Wherein, R ¹ is an alkylene group having 4 to 12 carbon atoms, R ² is an alkylene group having 1 to 3 carbon atoms, X is an alkoxy group, a carboxy group, an amino group or a hydroxyl group.)

（但し、Ｒ¹は炭素数が４〜１２のアルキレン基であり、Ｒ²は炭素数が１〜３のアルキレン基であり、Ｒ³は、炭素数が１〜４であるアルキル基である。）

(However, R ¹ is an alkylene group having 4 to 12 carbon atoms, R ² is an alkylene group having 1 to 3 carbon atoms, and R ³ is an alkyl group having 1 to 4 carbon atoms. )

（但し、Ｒ⁴は炭素数が４〜１２のアルキレン基である。）

(However, R ⁴ is an alkylene group having 4 to 12 carbon atoms.)

  Further, the paint may contain an acid catalyst. Examples of such an acid catalyst include oxalic acid, citric acid, p-toluenesulfonic acid, and the like. Thus, the solvent system used when printing is performed on a support sheet by causing a condensation reaction between repeating units represented by Formula 1 to form a crosslinked structure between molecules by containing an acid catalyst in the paint. The resistance to the solvent in the ink can be improved, and the deterioration of the adhesive properties of the adhesive layer 3 after printing on the support sheet 1 can be reliably prevented.

  If the content of the acid catalyst in the paint is small, the crosslinking may not be sufficient, and the resistance of the intermediate layer to the solvent in the solvent-based ink may decrease. 1-10 parts by weight is preferable with respect to 100 parts by weight of the synthetic resin, since 1.5% by weight with respect to 100 parts by weight of the synthetic resin. Is more preferable.

  The coating material may contain an alkoxysilane compound having at least one substituent selected from the group consisting of an amino group, a sulfanyl group, an epoxy group, an isocyanate group, an acryloyl group, and a methacryloyl group. The alkoxysilane compound preferably has an amino group when the support sheet is a plasticized polyvinyl chloride resin sheet.

  By including such an alkoxysilane compound, the adhesiveness between the support sheet 1 and the intermediate layer 2 can be improved, and both can be firmly integrated, and the re-peelable pressure-sensitive adhesive sheet for printing is attached. When peeling from a body, the situation where the support sheet 1 and the intermediate | middle layer 2 isolate | separate unexpectedly can be prevented.

  And, if the content of the alkoxysilane compound in the coating is small, the adhesiveness between the support sheet and the intermediate layer may not be sufficiently improved, while if large, the free product of the alkoxysilane compound is generated, As a result, the resistance of the intermediate layer to the solvent in the solvent-based ink may decrease, so that it is preferably 15 to 60 parts by weight and more preferably 20 to 50 parts by weight with respect to 100 parts by weight of the synthetic resin.

  Furthermore, the intermediate layer 2 may contain a polyester resin or a polyurethane resin in order to improve the integrity with the support sheet 1.

  Then, when the support sheet 1 and the intermediate layer 2 are laminated and integrated, when a synthetic resin sheet constituting the intermediate layer 2 is separately prepared, for example, a dry laminating method, a wet laminating method, a heat sealing method, an adhesive is used. The method of using is mentioned, The method of interposing an adhesive bond layer between the support sheet 1 and the intermediate | middle layer 2 is preferable.

  The adhesive that forms the adhesive layer is not particularly limited as a resin component as long as it has a higher adhesive force than the pressure-sensitive adhesive layer. For example, an epoxy adhesive or an acrylic adhesive is used. , Urethane adhesives, rubber adhesives, silicone adhesives, and the like, and urethane adhesives are preferred.

  In addition, as a urethane type adhesive agent, it is marketed by the brand name "Takelac A-543" from Mitsui Chemicals Polyurethane, for example, and the brand name "Takelac A-606" from Mitsui Chemicals Polyurethane. And those composed of an isocyanate curing agent (for example, commercially available from Mitsui Chemicals Polyurethanes under the trade name “Takenate A-50”).

  And when forming the intermediate | middle layer 2 using the coating material mentioned above, the said coating material is apply | coated to one surface of the supporting sheet 1 using a general purpose method, and the alcohol solvent in a coating material is evaporated and removed, and a supporting sheet. The method of forming the intermediate | middle layer 2 on one surface of 1 is mentioned.

  If the thickness of the intermediate layer 2 is thin, the solvent in the solvent-based ink may penetrate into the pressure-sensitive adhesive layer, and the cohesive force of the pressure-sensitive adhesive layer may be reduced. The flexibility is reduced, or the weight of the re-peelable pressure-sensitive adhesive sheet for printing may increase and handleability may decrease, so 0.2 to 20 μm is preferable.

  Further, an adhesive layer 3 is laminated and integrated on one surface of the intermediate layer 2. The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer 3 is not particularly limited as long as it has removability, and for example, an epoxy pressure-sensitive adhesive, an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, Examples thereof include a rubber-based pressure-sensitive adhesive and a silicone-based pressure-sensitive adhesive, and an acrylic pressure-sensitive adhesive is preferable because of excellent adhesion control and removability. In addition, the release paper 4 is normally laminated | stacked on the adhesive layer 3 so that peeling is possible.

  The method of laminating and integrating the pressure-sensitive adhesive layer 3 on one surface of the intermediate layer 2 is not particularly limited. For example, a method of applying a pressure-sensitive adhesive to one surface of the intermediate layer 2 and drying it, or applying a pressure-sensitive adhesive on the release paper For example, a method of transferring the pressure-sensitive adhesive on the release paper to one surface of the intermediate layer 2 and stacking and integrating them after drying. In addition, as a method of apply | coating an adhesive on the intermediate | middle layer 2 or a release paper, the well-known method using a gravure roll coater, a knife coater, a comma coater, a bar coater, a die coater etc. is employable.

  If the adhesive strength of the pressure-sensitive adhesive layer 3 is low, the re-peelable pressure-sensitive adhesive sheet for printing may not be stably adhered to the adherend, whereas if it is high, the re-peelable pressure-sensitive adhesive sheet for printing is sometimes used. When peeling from the adherend, it is difficult to peel the removable pressure-sensitive adhesive sheet for printing, and the releasable pressure-sensitive adhesive sheet for printing may be cut, so 3 to 15 N / 25 mm is preferable. 5-12N / 25mm is more preferable. In addition, the adhesive strength of the adhesive layer 3 is based on the method of 10.4.1 “180 degree peeling adhesive strength of an adhesive” of JIS Z0237-2000, using a stainless steel plate (SUS304) as an adherend. The measured value.

  Moreover, if the gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is low, the pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer is reduced, and the re-peelable pressure-sensitive adhesive sheet for printing can be stably adhered to the adherend. While it may not be possible, adhesive residue may occur on the adherend when the re-peelable pressure-sensitive adhesive sheet for printing is peeled off from the adherend, while if high, the adhesive strength of the pressure-sensitive adhesive layer decreases, Since the re-peelable pressure-sensitive adhesive sheet for printing may not be able to be stably adhered to the adherend, 30 to 80% by weight is preferable.

In addition, the gel fraction of an adhesive means what was measured in the following way. Remove the pressure-sensitive adhesive layer from the re-peelable pressure-sensitive adhesive sheet using a spatula or the like, or peel off the pressure-sensitive adhesive on the release paper before being transferred to one surface of the intermediate layer to obtain a test piece. The weight W _{1 of} this test piece Measure.

Next, after immersing the test piece in an ethyl acetate solvent maintained at room temperature for 24 hours, the test piece was filtered through a 200-mesh wire mesh, and the weight W _{2 of} the residue remaining on the wire mesh was vacuum-dried. Measure and calculate the gel fraction of the adhesive based on the following formula.
Gel fraction (% by weight) = 100 × W ₂ / W ₁

  Moreover, if the thickness of the pressure-sensitive adhesive layer 3 is thin, the adhesiveness of the removable pressure-sensitive adhesive sheet for printing to the adherend is lowered, and the removable pressure-sensitive adhesive sheet for printing cannot be stably adhered to the adherend. On the other hand, if it is thick, the adhesive will cause cohesive failure when peeling the printing releasable pressure-sensitive adhesive sheet from the adherend, resulting in adhesive residue on the adherend, or printing releasable pressure-sensitive adhesive. Since the pressure-sensitive adhesive protrudes from the edge of the sheet and may contaminate the surroundings, 5 to 100 μm is preferable.

  The form of the pressure-sensitive adhesive layer 3 is not particularly limited, and while maintaining the re-peelability of the re-peelable pressure-sensitive adhesive sheet for printing, the pressure-sensitive adhesive layer maintains the desired pressure-sensitive adhesive property for a long period of time, and the re-peeling for printing The surface of the pressure-sensitive adhesive layer 3 may be formed on a concavo-convex surface in order to facilitate the sticking of the adhesive sheet to the adherend.

  In this way, when the surface of the pressure-sensitive adhesive layer 3 of the re-peelable pressure-sensitive adhesive sheet for printing is an uneven surface, the re-peelable pressure-sensitive adhesive for printing is applied when the re-peelable pressure-sensitive adhesive sheet for printing is adhered to the adherend. The air entrained between the opposing surfaces of the pressure-sensitive adhesive layer 3 and the adherend of the sheet is easily discharged through the gap formed between the pressure-sensitive adhesive layer 3 and the adherend. The pressure-sensitive adhesive layer 3 can be attached in a state of being in close contact with the adherend.

  The form of the uneven surface of the pressure-sensitive adhesive layer 3 is not particularly limited. For example, (1) a surface in which a plurality of grooves are formed in parallel with each other at a predetermined interval on the surface of the pressure-sensitive adhesive layer 3; A structure in which a plurality of grooves are formed on the surface of the layer 3 in a lattice pattern, (3) a surface in which the columnar protrusions are projected on the surface of the pressure-sensitive adhesive layer 3, and (4) the surface of the pressure-sensitive adhesive layer 3 Further, for example, the groove pattern 31a as shown in FIG. 2 in which irregularly bent grooves are formed in an irregular manner, and a groove pattern different from the groove pattern 31a and irregularly bent grooves are irregular. The groove pattern 31b as shown in FIG. 3 formed in a regular manner is formed so as to be discontinuous and alternately formed, and the forms (1), (2), and (4) are preferable. In the forms of (1) and (2) above, it is more preferable that the groove portion opens on the end face of the pressure-sensitive adhesive layer 3. In the form (4), it is preferable that the groove portions of the groove pattern 31 a and 31 b do not open on the end face of the pressure-sensitive adhesive layer 3.

  As a point of forming a groove or a convex on the surface of the pressure-sensitive adhesive layer 3, for example, a method of pressing a template on which the ridges corresponding to the formation pattern of the groove are formed on the surface of the pressure-sensitive adhesive layer 3, a pressure-sensitive adhesive Examples include a method of forming an uneven part in a form in which a groove part and a convex part formed on the surface of the layer are inverted on a release paper, applying an adhesive on the uneven surface of the release paper, and drying.

  The printing removable pressure-sensitive adhesive sheet can be printed on the surface of the printing removable pressure-sensitive adhesive sheet using a solvent-based ink by a known printing method such as an inkjet printing method or a silk printing method. In addition, the re-peelable pressure-sensitive adhesive sheet for printing is used by adhering to a desired adherend by the pressure-sensitive adhesive layer, and after a predetermined period of time, the re-peelable pressure-sensitive adhesive sheet for printing is It is peeled off from the adherend.

  At this time, the re-peelable pressure-sensitive adhesive sheet for printing of the present invention has the intermediate layer 2 interposed between the support sheet 1 and the pressure-sensitive adhesive layer 3, and the re-peelable pressure-sensitive adhesive sheet for printing is inkjet printing or silk printing. Even when printing is performed using solvent-based ink, the solvent contained in the solvent-based ink does not reach the pressure-sensitive adhesive layer. There is no risk of degradation.

  Therefore, the re-peelable pressure-sensitive adhesive sheet for printing adheres to the adherend stably over a predetermined period, and does not cause any floating or gap between the adherend and adheres in a beautiful state. In addition, after a predetermined period of time has elapsed, it can be exfoliated and removed without causing adhesive residue from the adherend.

  Moreover, since the releasable pressure-sensitive adhesive sheet for printing uses the specific intermediate layer 2 as its intermediate layer, it is excellent in flexibility and can be smoothly applied to an adherend having a curved surface or a complicated surface shape. Adhering beautifully to the adherend with no gap while following the surface shape, and without peeling to the adherend over time, it stays beautiful for a long time It can be reliably adhered to the surface of the adherend.

  The re-peelable pressure-sensitive adhesive sheet for printing according to the present invention is a re-peelable pressure-sensitive adhesive sheet for printing in which a pressure-sensitive adhesive layer is laminated and integrated on one surface of a support sheet, and is between the support sheet and the pressure-sensitive adhesive layer. , Because it is made of a synthetic resin having a glass transition temperature of −50 to 60 ° C. and an intermediate layer having a tensile elongation at break of 100 to 500% is interposed. It can be adhered beautifully while smoothly following an adherend having a complicated surface shape, and the state can be stably maintained over a long period of time.

Example 1
A white plasticized polyvinyl chloride sheet (trade name “OIY-120” manufactured by Okamoto Co., Ltd.) having a thickness of 100 μm was prepared as a support sheet.

  As the repeating unit, a repeating unit having the structural formula represented by Formula 4 and a repeating unit having the structural formula represented by Formula 5 and having the structural formula represented by Formula 5 are provided. 50 parts by weight of modified 6-nylon (trade name “FR-101” manufactured by Lead City Co., Ltd.) having 30 mol% in the molecule and 950 parts by weight of ethyl alcohol are added in small portions while stirring in a 60 ° C. warm bath under reflux. To obtain a paint.

  Next, 1.5 parts by weight of p-toluenesulfonic acid and 20 parts by weight of 3- (2-aminoethyl) aminopropyltrimethoxysilane (manufactured by Shin-Etsu Silicone Co., Ltd., “KBM-603”) are uniformly added to the paint. The mixture was stirred and mixed.

  Then, the coating is applied to one side of the plasticized polyvinyl chloride sheet with a bar coat so that the thickness after drying is 2 μm, and dried at 40 ° C. for 1 minute. The layers were laminated and integrated to obtain a laminated sheet. The glass transition temperature of the modified 6-nylon constituting the intermediate layer was 20 to 30 ° C., and the tensile elongation at break of the intermediate layer was 400%.

  On the other hand, a re-peelable acrylic pressure-sensitive adhesive (trade name “SK Dyne MS-10” manufactured by Soken Chemical Co., Ltd.) and a curing agent (trade name “Coronate L-28E” manufactured by Nippon Polyurethane Co., Ltd.) of 100: 2.94. After mixing at a weight ratio, the above-mentioned re-peelable acrylic pressure-sensitive adhesive is applied to the release-treated surface of a release paper (trade name “K8 Shiro PL” manufactured by Lintec Corporation) so that the thickness after drying is 50 μm. And dried at 110 ° C. for 5 minutes to obtain an adhesive layer. In addition, the unevenness | corrugation as shown in FIG. 2 was formed in the mold release process surface of a release paper, the groove width was 500 micrometers and the groove depth was 25 micrometers.

  Then, the release paper is placed on the intermediate layer of the laminated sheet so that the pressure-sensitive adhesive layer faces the intermediate layer, the pressure-sensitive adhesive layer is transferred onto the intermediate layer, laminated and integrated, and the plasticized A re-peelable pressure-sensitive adhesive sheet for printing in which an intermediate layer and a pressure-sensitive adhesive layer were sequentially laminated and integrated on one surface of a vinyl chloride sheet was obtained. In addition, the release paper was laminated | stacked on the adhesive layer of the releasable adhesive sheet for printing so that peeling was possible.

(Example 2)
3- (2-aminoethyl) aminopropyltrimethoxysilane (trade name “KBM-603” manufactured by Shin-Etsu Silicone Co., Ltd.) was changed to 10 parts by weight instead of 20 parts by weight, and one side of the plasticized polyvinyl chloride sheet A re-peelable pressure-sensitive adhesive sheet for printing was obtained in the same manner as in Example 1 except that a corona discharge treatment was performed at 20 m / min and 0.4 kW. The glass transition temperature of the modified 6-nylon constituting the intermediate layer was 20 to 30 ° C., and the tensile elongation at break of the intermediate layer was 400%.

(Comparative Example 1)
A polyethylene terephthalate sheet (trade name “Embret PET-12F” manufactured by Unitika Ltd.) having a thickness of 12 μm was prepared. Then, a urethane adhesive (trade name “Takelac A-543” manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) and a curing agent (trade name “Takenate A-50” manufactured by Mitsui Chemicals Polyurethane Co., Ltd.) are mixed at a weight ratio of 9: 1. Then, the urethane adhesive was applied to one surface of the polyethylene terephthalate sheet so that the thickness after drying was 3 μm, dried at 110 ° C. for 2 minutes, and then the thickness was deposited on the urethane adhesive. Was laminated with a white plasticized polyvinyl chloride sheet (trade name “OIY-120” manufactured by Okamoto Co., Ltd.) having a thickness of 100 μm and cured at 40 ° C. for 48 hours to obtain a laminated sheet. In addition, the glass transition temperature of the polyethylene terephthalate sheet was 70 to 80 ° C., and the tensile elongation at break of the polyethylene terephthalate sheet was 130%.

  Further, the polyethylene terephthalate sheet surface of the laminated sheet was subjected to corona discharge treatment under the conditions of 20 m / min and 0.4 kW. On the other hand, an adhesive layer was laminated and integrated on one surface of the release paper in the same manner as in Example 1.

  Next, the release paper was superimposed on the polyethylene terephthalate sheet of the laminated sheet so that the pressure-sensitive adhesive layer was opposed to the polyethylene terephthalate sheet, and the pressure-sensitive adhesive layer on the release paper was transferred onto the polyethylene terephthalate for 48 hours at 40 ° C. The adhesive layer was laminated and integrated on polyethylene terephthalate to obtain a re-peelable pressure-sensitive adhesive sheet for printing.

(Comparative Example 2)
Instead of the laminated sheet, a white plasticized polyvinyl chloride sheet (trade name “OIY-120” manufactured by Okamoto Co., Ltd.) was used, and the pressure-sensitive adhesive layer was transferred to one surface of the plasticized polyvinyl chloride sheet. A re-peelable pressure-sensitive adhesive sheet for printing was obtained in the same manner as in Comparative Example 1 except that.

  Using an inkjet printer (trade name “SOLJET PROIII XC-540” manufactured by Roland DG) on the surface of the plasticized polyvinyl chloride sheet of the releasable pressure-sensitive adhesive sheet for printing obtained in Examples and Comparative Examples, C (Cyan), M (Magenta), Y (Yellow), and K (Black) are set to 100%, and the ICC profile “SFPLF” is output twice (400%). And dried for 1 day.

  The gel fraction of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer of the obtained re-peelable pressure-sensitive adhesive sheet for printing, as well as the adhesive strength, print resistance, re-peelability of the obtained re-peelable pressure-sensitive adhesive sheet for printing, The sheet strength, sticking property and bending workability were measured before and after the printing based on the following points, and the results are shown in Table 1.

(Adhesive force)
A stainless steel plate (SUS304) is prepared as an adherend, and a printing releasable pressure-sensitive adhesive sheet is attached to the surface of the stainless steel plate, and the adhesive strength of the printing releasable pressure-sensitive adhesive sheet is determined according to JIS Z0237-2000 10.4. 1 It measured based on the method of "180 degree peeling adhesive strength of an adhesive".

(Print resistance)
Compare the above adhesive strength of the re-peelable adhesive sheet for printing before and after printing, and when the adhesive strength after printing is 60% or more of the adhesive strength before printing, the adhesive strength after printing is the adhesive strength before printing The case where it was less than 60% of was made into x.

(Initial removability)
A test piece having a plane rectangular shape of 25 mm in length and 100 mm in width was cut out from the releasable pressure-sensitive adhesive sheet for printing, and this test piece was attached to a stainless steel plate (SUS304) and left at room temperature for 3 days. Next, the edge part of the length direction of the test piece was hold | gripped by hand, and the test piece was peeled from the stainless steel plate at high speed. Then, the area S ₁ (mm ² ) of the remaining adhesive portion remaining on the stainless steel plate was measured, and the remaining adhesive degree was calculated based on the following formula and evaluated according to the following criteria. In addition, when the test piece broke in the middle, the adhesive layer of the test piece remaining on the stainless steel plate was used as the adhesive remaining portion.
Adhesive residue index _{(%) = 100 × S 1} /2500
○: The adhesive residue was less than 10%.
Δ: Adhesive residue was 10% or more and less than 50%.
X: The adhesive residue was 50% or more.

(Removability after heating acceleration test)
Instead of leaving at room temperature for 3 days, evaluation was performed in the same manner as the initial peelability except that it was left at 60 ° C. for 7 days.

(Initial sheet strength)
A test piece having a plane rectangular shape of 25 mm in length and 100 mm in width was cut out from the releasable pressure-sensitive adhesive sheet for printing, and this test piece was attached to a stainless steel plate (SUS304) and left at room temperature for 3 days. Next, the edge part of the length direction of the test piece was hold | gripped by hand, and the test piece was peeled from the stainless steel plate at high speed. And what was able to peel a test piece easily without a fracture | rupture was made into (circle), what was able to peel the test piece without the fracture | rupture was (circle), and what the test piece broke in the middle of peeling was set as x.

(Sheet strength after heating acceleration test)
Instead of leaving it at room temperature for 3 days, it was evaluated in the same manner as the initial sheet strength except that it was left at 60 ° C. for 7 days.

(Adhesiveness)
A test piece having a plane rectangular shape of 25 mm in length and 100 mm in width was cut out from the releasable pressure-sensitive adhesive sheet for printing, and this test piece was attached to a stainless steel plate (SUS304). Under the present circumstances, it was made for the edge part 10mm of the length direction of a test piece to be in the state which protruded from the edge part of a stainless steel plate. After leaving in this state for 1 day at room temperature, the end of the test piece protruding from the stainless steel plate was folded over and superposed on the test piece portion pasted on the stainless steel plate. In this state, the pasting state of the test piece portion stuck on the stainless steel plate was visually observed and evaluated based on the following criteria.
○: Peeling did not occur in the test piece part pasted on the stainless steel plate.
X: Peeling occurred on the test piece part stuck on the stainless steel plate.

(Curved surface workability)
A flat rectangular test piece 6 having a length of 100 mm and a width of 25 mm was cut out from the re-peelable pressure-sensitive adhesive sheet for printing.

On the other hand, as shown in FIG. 4, as the adherend 5, an aluminum plate was prepared, in which trapezoidal sections having a trapezoidal cross section were projected at intervals of 20 mm. The protrusions had a height H of 5 mm, L ₁ of 20 mm, and L ₂ of 2 mm.

  As shown in FIG. 5, the test piece 6 was stretched between the protrusions on the protrusion-forming surface of the adherend 5 so as not to be loosened by the adhesive. Thereafter, the test piece 6 is heated by using a dryer, and the portion between the protrusions is pressed toward the adherend 5 as shown in FIG. It was stuck to the state along the unevenness.

  And the state of each test piece 6 after leaving the test piece 6 still for 24 hours and 5 days under 40 degreeC is visually observed, The part which the test piece 6 peels from the to-be-adhered body 5 The presence or absence of was investigated. The case where the test piece 6 was not peeled off from the adherend 5 at all was indicated as “◯”, and the case where there was a portion where the test piece 6 was peeled off from the adherend 5 was indicated as “x”.

It is the longitudinal cross-sectional view which showed the releasable adhesive sheet for printing of this invention. It is the model top view which showed an example of the groove part pattern formed in the surface of an adhesive layer. It is the model top view which showed an example of the groove part pattern formed in the surface of an adhesive layer. It is a side view of the adherend used in the curved surface workability test. In a curved surface workability test, it is a side view showing a state in which a test piece is stretched on an adherend. It is the side view which showed the state which affixed the test piece on the to-be-adhered body in the bending workability test.

Explanation of symbols

1 Support sheet 2 Non-metal sheet 3 Adhesive layer
31a, 31b Groove pattern 4 Release paper

Claims (15)

A re-peelable pressure-sensitive adhesive sheet for printing in which a pressure-sensitive adhesive layer is laminated and integrated on one surface of a support sheet, and has a glass transition temperature of −50 to 60 ° C. between the support sheet and the pressure-sensitive adhesive layer. An intermediate layer comprising a linear aliphatic polyamide resin having at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group and a hydroxyl group, and having a tensile elongation at break of 200 to 500% A re-peelable pressure-sensitive adhesive sheet for printing, characterized by being interposed. The releasable pressure-sensitive adhesive sheet for printing according to claim 1 , wherein the linear aliphatic polyamide resin constituting the intermediate layer has an alkylene group having 4 to 12 carbon atoms in the main chain. The re-peelable pressure-sensitive adhesive sheet for printing according to claim 1, wherein the linear aliphatic polyamide resin is modified 6-nylon.   The re-peelable pressure-sensitive adhesive sheet for printing according to claim 1, wherein the support sheet has a thickness of 40 to 120 µm, the intermediate layer has a thickness of 0.2 to 20 µm, and the pressure-sensitive adhesive layer has a thickness of 5 to 100 µm.   The re-peelable pressure-sensitive adhesive sheet for printing according to claim 1, wherein the support sheet can be printed with a solvent-based ink. A re-peelable pressure-sensitive adhesive sheet for printing in which a pressure-sensitive adhesive layer is laminated and integrated on one surface of a support sheet, and has a glass transition temperature of −50 to 60 ° C. between the support sheet and the pressure-sensitive adhesive layer. An intermediate layer made of a synthetic resin and having an elongation at break of 200 to 500% is interposed, and the intermediate layer is at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group, and a hydroxyl group A coating containing at least one synthetic resin selected from the group consisting of a polyester resin, a polyurethane resin, a silicone resin and a linear aliphatic polyamide resin and an alcohol solvent is applied to one surface of the support sheet. printing removable adhesive sheet, characterized in der Rukoto those formed by drying. The releasable pressure-sensitive adhesive sheet for printing according to claim 6 , wherein the synthetic resin constituting the intermediate layer is a synthetic resin having an alkylene group having 4 to 12 carbon atoms in the main chain. The synthetic resin is a linear aliphatic polyamide resin containing 10 mol% or more of repeating units having at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group and a hydroxyl group in the molecule. The re-peelable pressure-sensitive adhesive sheet for printing according to claim 6 . The re-peelable pressure-sensitive adhesive sheet for printing according to claim 8 , wherein the repeating unit is a structural formula represented by Formula 1.

(Wherein, R ¹ is an alkylene group having 4 to 12 carbon atoms, R ² is an alkylene group having 1 to 3 carbon atoms, X is an alkoxy group, a carboxy group, an amino group or a hydroxyl group.) The re-peelable pressure-sensitive adhesive sheet for printing according to claim 9 , wherein X is an alkoxy group. The re-peelable pressure-sensitive adhesive sheet for printing according to claim 6 , wherein the paint contains an acid catalyst. Claim paint, amino group, sulfanyl group, an epoxy group, isocyanate group, characterized by containing an alkoxysilane compound having at least one substituent selected from the group consisting of acryloyl group and methacryloyl group 6 Re-peelable pressure-sensitive adhesive sheet for printing described in 1. One surface of the support sheet has at least one substituent selected from the group consisting of an alkoxy group, a carboxyl group, an amino group and a hydroxyl group, and has a glass transition temperature of −50 to 60 ° C., a polyester resin and a polyurethane resin An intermediate having a tensile elongation at break of 200 to 500% by applying and drying a paint containing at least one synthetic resin selected from the group consisting of a silicone resin and a linear aliphatic polyamide resin and an alcohol solvent A method for producing a releasable pressure-sensitive adhesive sheet for printing, comprising: laminating and integrating layers, and applying and drying an adhesive on the intermediate layer and drying the adhesive layer. The method for producing a releasable pressure-sensitive adhesive sheet for printing according to claim 13 , wherein the support sheet is a polyvinyl chloride resin sheet. The method for producing a releasable pressure-sensitive adhesive sheet for printing according to claim 13 , wherein the alcohol solvent is a lower alcohol having 1 to 3 carbon atoms.

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