JP2010254741A - Adhesive tape for temporary fixing of article, and temporarily fixed article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adhesive tape for temporary fixing of an article which is extremely hardly peeled even when a stress is caused in a state in which the tape is adhered to a part of an article to be adhered, can be easily peeled when the tape is peeled after the purpose is attained, and extremely hardly causes an adhesive residual deposit. <P>SOLUTION: This adhesive tape for temporary fixing of an article includes an adhesive layer on one side of a base material in which the base material is a uniaxial oriented polypropylene-based film; the adhesive layer contains as a main component, an alkyl (meth)acrylate having a 4-12C alkyl group and is formed from an acrylic emulsion-type adhesive containing an acrylic copolymer emulsion obtained from a monomer mixture containing methacrylic acid and an oxazoline group-containing aqueous crosslinker; and between the base material and the adhesive layer, there is interposed an undercoating layer formed from a solvent-type amino group-grafted acrylic resin. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an adhesive tape used for temporarily fixing an article. The present invention also relates to a temporarily fixed article in which the article is temporarily fixed by the adhesive tape. The pressure-sensitive adhesive tape of the present invention is used in a tape shape or a sheet shape.

  The adhesive tape for temporarily fixing and fixing the article of the present invention is, for example, when packing the article as an adherend when shipping the article such as an electrical appliance or an OA device, and the like, an internal part of the article, a door, etc. In order to temporarily fix and fix a portion to be adhered (for example, a printed steel plate or a resin plate), it is used by being attached to the portion to be adhered. For example, when the article is a refrigerator, the pressure-sensitive adhesive tape of the present invention is used for temporarily fixing a refrigerator door or the like.

  The properties required for adhesive tapes used for temporarily fixing and fixing articles such as electrical appliances and OA equipment include adhesives to securely fix the internal parts of the articles that are adherends and the parts to be attached such as doors. It is required that the tape does not peel even if stress is generated in a state where the tape is attached to the adherend portion. In addition, when the article is used, the adhesive tape that is no longer needed is finally peeled off from the adherend, and therefore the adhesive tape is required to be easily peeled off. Thus, the temporarily fixing adhesive tape is required to have contradictory characteristics.

  As an adhesive tape for temporarily fixing, one having an adhesive layer formed on one side or both sides of a support is known. Since the temporarily fixing adhesive tape is required to be as inexpensive as possible, the same adhesive tape as that for cardboard box sealing is usually used (Patent Document 1). For example, a pressure-sensitive adhesive tape in which a pressure-sensitive adhesive layer is formed on one surface of a base material made of a general-purpose stretched polypropylene (OPP) film and a release agent layer is formed on the other surface has been generally used. In recent years, adhesive tapes based on polyethylene terephthalate (PET) film or longitudinally uniaxially stretched polypropylene film having higher substrate strength instead of OPP film have been used.

  On the other hand, organic solvent-type adhesives were used as adhesives used for temporarily fixing adhesive tapes. However, as with ordinary adhesives, social protection for environmental protection, resource conservation, health and safety, etc. Due to general demands and stricter regulations, water-based adhesives are being used as adhesives to replace organic solvent adhesives. As the water-based adhesive, an acrylic emulsion-type adhesive is usually used.

  A pressure-sensitive adhesive layer formed by applying an acrylic emulsion-type pressure-sensitive adhesive has a high adhesive force to an adherent part (for example, a printed steel plate or a resin plate) of an article such as a home appliance. However, the adhesive force between the base material and the pressure-sensitive adhesive layer formed from the acrylic emulsion-type pressure-sensitive adhesive is weak. For this reason, when the adhesive tape for temporarily fixing is peeled off from the adherend, the printed surface of the adherend portion is scraped off, or adhesive residue is generated on the adherend due to the interlaminar fracture of the adhesive layer. was there.

  In order to solve the above problem, the present applicant has proposed an adhesive tape for temporarily fixing (Patent Document 2). However, depending on the material of the adherend, the adhesive tape may have a slightly insufficient adhesive force, and when exposed to a high temperature and high humidity for a long period of time, adhesive residue may remain depending on the material of the adherend. It sometimes occurred.

JP-A 63-86786 JP 2006-282746 A

  The present invention is very difficult to peel off even when stress is generated in a state where it is applied to the adherend part of the article, and can be easily peeled off when the object is peeled off after achieving the purpose. It is an object of the present invention to provide an adhesive tape for temporarily fixing and fixing an article, which hardly causes a residue.

  Another object of the present invention is to provide a temporarily fixed article in which the article is temporarily fixed by the adhesive tape.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by the following adhesive tape, and have completed the present invention.

That is, the present invention has a pressure-sensitive adhesive layer on one side of a substrate, and an adhesive tape for temporarily fixing and fixing an article.
The substrate is a uniaxially stretched polypropylene film,
Acrylic copolymer emulsion and oxazoline group-containing aqueous system obtained from a monomer mixture in which the pressure-sensitive adhesive layer is mainly composed of an alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms and containing methacrylic acid It is formed with an acrylic emulsion-type pressure-sensitive adhesive containing a crosslinking agent,
The present invention relates to an adhesive tape for temporarily fixing an article characterized by having an undercoat layer formed of a solvent-type amino group-grafted acrylic resin between a base material and an adhesive layer.

  The pressure-sensitive adhesive tape for temporarily fixing according to the present invention is a monomer mixture containing, as a main component, an alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms and containing methacrylic acid as a material for forming an adhesive layer. Using the resulting acrylic copolymer emulsion and an acrylic emulsion-type pressure-sensitive adhesive containing an oxazoline group-containing aqueous cross-linking agent, the adhesive force to various adherends (adhered portions) is very good, Even if stress is generated in a state where an adhesive tape is applied to the adherend portion, it is difficult to peel off, and the article can be securely fixed temporarily.

  In the present invention, a uniaxially stretched polypropylene film having good mechanical strength is used as the base material, and the acrylic emulsion-type pressure-sensitive adhesive used for forming the pressure-sensitive adhesive layer has an oxazoline group-containing water-based cross-linking agent as the cross-linking agent. In addition, an undercoat layer is provided between the base material and the pressure-sensitive adhesive layer using a solvent-type amino group-grafted acrylic resin. Thus, in this invention, the adhesiveness of a base material and an adhesive layer is improved markedly by selecting and using as a base material, the material of an adhesive layer, and the material of undercoat, respectively. Therefore, the adhesive tape for temporary fixing of the present invention can be easily peeled off from the adherend after achieving the purpose, making it difficult to scrape the printed surface of the adherend and to leave no adhesive residue. ing. Further, the adhesive layer of the adhesive tape for temporary fixing of the present invention has good adhesive force and also good cohesive strength (holding force). It is difficult to produce adhesive residue. Furthermore, the adhesive layer of the temporary fixing tape of the present invention is excellent in that no adhesive residue is generated regardless of the material of the adherend even when exposed to high temperature and high humidity conditions for a long time. Yes.

  As described above, the adhesive tape for temporary fixing of the present invention has an adhesive force that can securely fix the adhered portion of the article, and can be easily peeled off without adhesive residue. Can satisfy the contradictory properties of the releasability and peelability. In the domestic specification of household electrical appliances exemplified as an article to which the temporary fixing fixing adhesive tape is applied, the environmental temperature in the distribution stage is assumed to be in the range of -20 ° C to + 50 ° C. The fixing tape for fixing is preferably used in the above specifications.

  The monomer mixture preferably further contains (meth) acrylonitrile. By further adding (meth) acrylonitrile as a monomer component, the adhesive force of the pressure-sensitive adhesive layer can be further improved.

  The monomer mixture is preferably mainly composed of an alkyl (meth) acrylate having 4 to 7 carbon atoms in the alkyl group and an alkyl (meth) acrylate having 8 to 12 carbon atoms in the alkyl group. By using two kinds of alkyl (meth) acrylates together, even when the adhesive layer is exposed to a high temperature and high humidity condition for a long period of time, the adhesive residue is more effectively prevented regardless of the material of the adherend. be able to.

  The acrylic copolymer in the acrylic copolymer emulsion preferably has a weight average molecular weight of 100,000 to 500,000. When the weight average molecular weight is less than 100,000, the cohesive force tends to decrease, and when it exceeds 500,000, the adhesive force tends to decrease.

  Furthermore, the present invention relates to a temporarily fixed article in which the article is temporarily fixed by the temporary fixing fixing adhesive tape.

  The adhesive tape for temporarily fixing and fixing the article of the present invention uses a uniaxially stretched polypropylene film as a substrate. A uniaxially stretched polypropylene film is preferable because of its excellent mechanical strength. From the viewpoint of mechanical strength, it is preferable to use a polypropylene film having a thickness in the range of 30 to 60 μm because it can reliably temporarily fix parts of household electrical appliances. If the thickness is less than 30 μm, the film is likely to be cut, and the strength may be insufficient to securely fix the parts of the home appliance. On the other hand, if the thickness exceeds 60 μm, the steel properties are high and difficult to handle, and the cost increases, which is not preferable.

  The surface of the polypropylene film is preferably subjected to corona discharge treatment. Moreover, printing etc. can be given to a polypropylene film as needed. Also, on the side of the polypropylene film where the adhesive layer is not provided, a back treatment layer is provided with a long-chain alkyl-based or silicone-based back treatment agent in order to ensure releasability when the adhesive tape is wound. Also good.

  The acrylic emulsion-type pressure-sensitive adhesive forming the pressure-sensitive adhesive layer in the temporary fixing tape of the present invention contains an alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms as a main component and also contains methacrylic acid. Contains an acrylic copolymer emulsion obtained from a monomer mixture. Alkyl (meth) acrylate means alkyl acrylate and / or alkyl methacrylate.

  Examples of the alkyl (meth) acrylate having 4 to 12 carbon atoms in the alkyl group include butyl (meth) acrylate, isobutyl (meth) acrylate, isoamyl (meth) acrylate, hexyl (meth) acrylate, hebutyl (meth) acrylate, 2- Examples thereof include ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, and one or more of these are used. Among these, it is preferable to use together an alkyl (meth) acrylate having 4 to 7 carbon atoms in the alkyl group and an alkyl (meth) acrylate having 8 to 12 carbon atoms in the alkyl group, and in particular, butyl (meth). It is preferable to use acrylate in combination with 2-ethylhexyl (meth) acrylate.

  The alkyl (meth) acrylate having 4 to 12 carbon atoms in the alkyl group is preferably used in an amount of 50 to 99.9% by weight, more preferably 70 to 98% in all monomers constituting the acrylic copolymer emulsion. % By weight, more preferably 80 to 96% by weight. When the proportion of the alkyl (meth) acrylate is small, it is difficult to obtain a good adhesive. Moreover, when using together the alkyl (meth) acrylate whose carbon number of an alkyl group is 4-7, and the alkyl (meth) acrylate whose carbon number of an alkyl group is 8-12, the weight ratio is 3: 97- It is preferably 30:70 (the former: the latter), more preferably 5:95 to 25:75.

  In addition to alkyl (meth) acrylates having 4 to 12 carbon atoms in the alkyl group, the monomers constituting the acrylic copolymer emulsion can be used to improve adhesion to adherends and introduce crosslinking points. Methacrylic acid is used for the purpose of increasing the cohesive strength of the adhesive and increasing the heat resistance and moisture resistance of the adhesive.

  Methacrylic acid is preferably used in an amount of 1 to 10% by weight, more preferably 2 to 6% by weight, and still more preferably 3 to 5% by weight, based on all monomers constituting the acrylic copolymer emulsion. When methacrylic acid is less than 1% by weight, the cohesive force is lowered, the adhesion to the substrate is lowered, and it is difficult to increase the heat resistance and moisture resistance of the pressure-sensitive adhesive. On the other hand, when it exceeds 10% by weight, the tackiness tends to decrease.

  Moreover, you may use a monomer other than the above for an acrylic copolymer emulsion in the range which does not have trouble in the characteristic of this invention. The other monomer is preferably used in a proportion of 10% by weight or less, more preferably 2 to 8% by weight, and further preferably 3 to 6% in the total monomers constituting the acrylic copolymer emulsion. % By weight.

  Other monomers include hydroxyl group-containing monomers such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate; (meth) acrylamide, N, N Amide group-containing monomers such as dimethyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide; 2- (N, N-dimethylamino) ) Amino group-containing monomers such as ethyl (meth) acrylate; Glycidyl group-containing monomers such as glycidyl (meth) acrylate; propyltrimethoxysilane (meth) acrylate, propyldimethoxysilane (meth) acrylate, propyltriethoxysilane (Meth) acrylate, etc. Alkoxysilyl group-containing monomer, (meth) acrylonitrile, N- (meth) acryloyl morpholine, N- vinyl-2-pyrrolidone. In addition, alkyl (meth) acrylates having 1 to 3 carbon atoms of alkyl groups such as methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, etc .; tridecyl (meth) acrylate, stearyl (meth) acrylate, etc. Examples thereof include alkyl (meth) acrylates having 13 to 18 carbon atoms in the alkyl group, vinyl acetate, styrene, and vinyl toluene. Also, neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate, propylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol hexa ( Examples thereof include those having two or more polymerizable functional groups such as (meth) acrylate. These monomers can be used alone or in combination of two or more.

  Of these, it is particularly preferable to use (meth) acrylonitrile. (Meth) acrylonitrile means acrylonitrile and / or methacrylonitrile.

  The acrylic copolymer emulsion is obtained by subjecting the monomer to emulsion polymerization by a conventional method using an appropriate polymerization initiator in the presence of an emulsifier. Emulsion polymerization is performed by general batch polymerization, continuous dropping polymerization, divided dropping polymerization, or the like.

  As the emulsifier, anionic emulsifiers and nonionic emulsifiers used in emulsion polymerization can be used without particular limitation. For example, anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzene sulfonate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, etc. Nonionic emulsifiers and the like. In addition, cationic emulsifiers and amphoteric emulsifiers can be used. Although the usage-amount of an emulsifier is not restrict | limited in particular, It is preferable to set it as about 0.3-5 weight part with respect to 100 weight part of monomers (total).

  Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis (N, N′-dimethyleneisobutyl). Azo initiators such as amidine), persulfate initiators such as potassium persulfate and ammonium persulfate, peroxide initiators such as benzoyl peroxide and t-butyl hydroperoxide, and persulfates and sulfites. Examples thereof include redox initiators such as sodium hydrogen. In the emulsion polymerization, an appropriate chain transfer agent typified by mercaptans may be used as necessary to adjust the molecular weight of the resulting copolymer.

  The acrylic copolymer in the acrylic copolymer emulsion preferably has a weight average molecular weight of 100,000 to 500,000, more preferably 250,000 to 400,000. When the weight average molecular weight is less than 100,000, the cohesive force of the acrylic emulsion-type pressure-sensitive adhesive tends to decrease, and the adhesion to the substrate tends to decrease. On the other hand, when it exceeds 500,000, the adhesive force tends to be low. The weight average molecular weight is a value obtained by measuring tetrahydrofuran-soluble content by GPC (gel permeation chromatography).

  The acrylic emulsion-type pressure-sensitive adhesive of the present invention contains the above acrylic copolymer emulsion and an oxazoline group-containing aqueous crosslinking agent. The oxazoline group-containing aqueous crosslinking agent can be used without limitation as long as it has an oxazoline group in the molecule and is water-dispersible or water-soluble. For example, 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4- An aqueous crosslinking agent obtained by emulsion polymerization or the like using one or more addition polymerizable oxazolines such as methyl-2-oxazoline and 2-isopropenyl-5-ethyl-2-oxazoline is used. Specific examples include “Epocross WS-500” and “Epocross WS-700” manufactured by Nippon Shokubai Co., Ltd.

  The blending amount of the oxazoline group-containing water-based crosslinking agent (solid content) is preferably 0.01 to 10 parts by weight, more preferably 0.8 parts per 100 parts by weight (solid content) of the acrylic copolymer emulsion. 1 to 5 parts by weight. When the blending amount is less than 0.01 parts by weight, the oxazoline group as a crosslinking agent is reduced, so that the cohesive force is lowered and the adhesion to the substrate may be lowered. On the other hand, when the blending amount exceeds 10 parts by weight, the adhesive strength tends to decrease.

  Furthermore, various additives such as a softener, a plasticizer, a tackifier, an anti-aging agent, and a colorant can be used in the acrylic emulsion-type pressure-sensitive adhesive as long as the properties thereof are not impaired. In addition, as a regulator of the reaction rate of the carboxyl group in the oxazoline group and the acrylic copolymer emulsion, a metal hydroxide compound such as sodium hydroxide that forms a salt with the carboxyl group, basic such as ammonia and alkylamine A compound can be blended.

  The acrylic emulsion-type pressure-sensitive adhesive of the present invention preferably has a glass transition temperature of −10 to −80 ° C., more preferably −20 to −70 ° C., and further preferably −20 to −60 ° C. It is. The glass transition temperature is a value measured by DSC (differential thermal analysis).

  The pressure-sensitive adhesive tape for temporarily fixing an article of the present invention has an undercoat layer formed of an amino group-grafted acrylic resin between the base material and the pressure-sensitive adhesive layer.

  As the undercoat used for forming the undercoat layer, a solvent-type acrylic resin grafted with an amino group can be used without particular limitation. For example, amino group-grafted acrylic resins include aminoethylated acrylic resins. The aminoethylated acrylic resin has a primary amino group in the molecule, and is generally a method for aminoethylation by reacting an acrylic polymer having a carboxyl group in the molecule with ethyleneimine. Is obtained. The acrylic polymer can be obtained by polymerizing an alkyl (meth) acrylate and a copolymer monomer thereof constituting the base polymer of the acrylic pressure-sensitive adhesive exemplified above according to a conventional method. As the comonomer, a carboxyl group-containing monomer is used for reacting ethyleneimine and the like. The proportion of the carboxyl group-containing monomer is appropriately adjusted depending on the proportion of ethyleneimine to be reacted. In the acrylic polymer, a styrene monomer or the like can be used as a comonomer.

  The aminoethylated acrylic resin preferably has a weight average molecular weight of 80,000 to 150,000 and a glass transition temperature of 35 to 45 ° C. When the weight average molecular weight of the aminoethylated acrylic resin is less than 80,000, the cohesive force of the undercoat layer itself is lowered, and the undercoat layer is destroyed when the adhesive tape is peeled off from the adherend, resulting in a paste residue. May occur. On the other hand, when the weight average molecular weight exceeds 150,000, the flexibility becomes poor, and when applied to the base material to form an undercoat layer, the followability to the base material is deteriorated and it is easy to peel off at the interface with the base material. . Further, if the glass transition temperature of the aminoethylated acrylic resin is lower than 35 ° C., the cohesive force tends to decrease at high temperatures in summer, and the undercoat layer tends to be broken when peeled off. On the other hand, when the glass transition temperature exceeds 45 ° C., the flexibility becomes poor, and when applied to the base material to form an undercoat layer, the followability to the base material is deteriorated and it is easy to peel off at the interface with the base material. .

  The amino group grafted acrylic resin may be obtained by grafting a polyethyleneimine adduct to an acrylic resin by the same method as described above. By the polyethyleneimine adduct, an acrylic resin in which the aminoethyl group of the terminal primary amine group is grafted is obtained. The ethyleneimine adduct can be grafted to an acrylic resin by addition polymerization of ethyleneimine, and the polyethyleneimine can be grafted by reacting separately synthesized polyethyleneimine with a carboxyl group in the acrylic resin. It can also be an added product.

  As a commercial product of solvent-type aminoethylated acrylic resin, there is “Polyment” series, among which “Polyment NK-350” (manufactured by Nippon Shokubai Co., Ltd., weight average molecular weight 100,000, glass transition temperature 40 ° C.), etc. Is mentioned. An emulsion type amino group grafted acrylic resin is not preferable in terms of adhesive residue.

  The pressure-sensitive adhesive tape for temporarily fixing an article of the present invention is provided with a pressure-sensitive adhesive layer on the base material via an undercoat layer formed of the undercoat agent.

  The undercoat layer is usually formed by applying an undercoat agent to the substrate and drying it. The thickness of the undercoat layer (after drying) is usually about 0.001 to 3 μm, preferably 0.01 to 2 μm, and more preferably 0.03 to 2 μm. If it is the thickness of this range, the adhesiveness of a base material and an adhesive layer can fully be improved.

  The pressure-sensitive adhesive layer can be formed by directly applying and drying the above-mentioned acrylic emulsion-type pressure-sensitive adhesive on the surface of the undercoat layer. The pressure-sensitive adhesive layer can also be formed by transferring the pressure-sensitive adhesive layer formed on the separator onto a substrate having an undercoat layer. The thickness (after drying) of the pressure-sensitive adhesive layer is usually about 10 to 50 μm, preferably 20 to 40 μm.

  Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. Hereinafter, “parts” means “parts by weight”. Evaluation items in Examples and the like were measured as follows.

<Measurement of weight average molecular weight>
The weight average molecular weight of the acrylic copolymer in the acrylic copolymer emulsion was measured by GPC (gel permeation chromatography). As a sample, an acrylic copolymer emulsion was dissolved in tetrahydrofuran to make a solution of about 0.1% by weight, and this was allowed to stand overnight, and then filtrated through a 0.45 μm membrane filter was used.
Analyzing device: manufactured by Tosoh Corporation, HLC-8120GPC
Column: manufactured by Tosoh Corporation, G7000H _XL -H + GMH _XL -H + GMH _XL
Column size: 7.8mmφ × 30cm each 90cm in total
Column temperature: 40 ° C
Flow rate: 0.8mL / min
Eluent: Tetrahydrofuran solution concentration: about 0.1% by weight
Injection volume: 100 μL
Detector: Differential refractometer (RI)
Standard sample: Polystyrene data processor: GPC-8020, manufactured by Tosoh Corporation

Example 1
(Base material)
A double-sided corona discharge treated product (NOWOFOL, MOPP PPCL30 # 40) of a 40 μm-thick longitudinal uniaxially stretched polypropylene film was used. The film has, on one surface, a solution obtained by dissolving a long-chain alkyl-based back-treating agent (manufactured by Yushi Co., Ltd., Pyroyl 1010) in a solvent (toluene) so that the dry thickness becomes 0.5 μm. It has a coated back treatment layer.

(Undercoat)
A solvent-type aminoethylated acrylic resin (manufactured by Nippon Shokubai Co., Ltd., Poliment NK-350) was used.

(Preparation of adhesive)
96 parts of n-butyl acrylate and 4 parts of methacrylic acid were emulsion polymerized in the presence of an anionic emulsifier to prepare an acrylic copolymer emulsion (weight average molecular weight: 200,000). Acrylic emulsion type pressure-sensitive adhesive containing 2 parts of oxazoline group-containing water-soluble crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., WS-700) (solid content conversion) to 100 parts of solid content of the acrylic copolymer emulsion. An agent was prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −50 ° C.

(Production of adhesive tape)
The undercoat was applied to one side of the substrate (the side not provided with the back treatment layer) so that the thickness after drying was 1 μm, and dried at 100 ° C. for 1 minute to form an undercoat layer. . Further, the acrylic emulsion-type pressure-sensitive adhesive is coated on the undercoat layer so that the thickness after drying becomes 30 μm, and dried at 120 ° C. for 3 minutes to form a pressure-sensitive adhesive layer to form a pressure-sensitive adhesive tape. Was made.

Example 2
An acrylic copolymer emulsion (weight average molecular weight: 200,000) was prepared in the same manner as in Example 1 except that 98 parts of n-butyl acrylate and 2 parts of methacrylic acid were used, and then an acrylic emulsion type pressure-sensitive adhesive was used. Prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −52 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Example 3
An acrylic copolymer emulsion (weight average molecular weight: 200,000) was prepared in the same manner as in Example 1 except that 96 parts of 2-ethylhexyl acrylate and 4 parts of methacrylic acid were used. Prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −68 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Example 4
An acrylic copolymer emulsion (weight average molecular weight: 200,000) was prepared in the same manner as in Example 1 except that 90 parts of 2-ethylhexyl acrylate, 6 parts of n-butyl acrylate and 4 parts of methacrylic acid were used. An acrylic emulsion-type pressure-sensitive adhesive was prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −65 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Example 5
An acrylic copolymer emulsion (weight average molecular weight: 300,000) was prepared in the same manner as in Example 1 except that 75 parts of 2-ethylhexyl acrylate, 21 parts of n-butyl acrylate and 4 parts of methacrylic acid were used. An acrylic emulsion-type pressure-sensitive adhesive was prepared. The acrylic emulsion-type pressure-sensitive adhesive had a glass transition temperature of −63 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Example 6
An acrylic copolymer emulsion (weight average molecular weight: 250,000) was prepared in the same manner as in Example 1 except that 86 parts of 2-ethylhexyl acrylate, 6 parts of n-butyl acrylate, 4 parts of methacrylic acid and 4 parts of acrylonitrile were used. After that, an acrylic emulsion-type pressure-sensitive adhesive was prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −61 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Example 7
An acrylic copolymer emulsion (weight average molecular weight: 300,000) was prepared in the same manner as in Example 1 except that 89 parts of 2-ethylhexyl acrylate, 6 parts of n-butyl acrylate, 1 part of methacrylic acid and 4 parts of acrylonitrile were used. After that, an acrylic emulsion-type pressure-sensitive adhesive was prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −64 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

Comparative Example 1
An acrylic copolymer emulsion (weight average molecular weight: 250,000) was prepared in the same manner as in Example 1 except that 98 parts of n-butyl acrylate and 2 parts of acrylic acid were used, and then an acrylic emulsion type pressure-sensitive adhesive was used. Prepared. The glass transition temperature of the acrylic emulsion-type pressure-sensitive adhesive was −52 ° C. And the adhesive tape was produced by the method similar to Example 1. FIG.

(Evaluation)
Using the pressure-sensitive adhesive sheets obtained in Examples and Comparative Examples, adhesive strength, shearing force, holding power, and adhesive residue on the adherend were measured and evaluated. Each measuring method and evaluation method are as follows. The evaluation results are shown in Table 1.

〔Adhesive force〕
A 25 mm wide adhesive sheet is made of stainless steel plate (SUS304BA), polycarbonate plate (PC plate), steel plate (zinc steel plate) and ABS plate (rough surface side) previously washed with toluene in 23 ° C x 60% RH. After bonding with a roller and leaving for 30 minutes, the resistance when the sample was peeled off in a 180 ° direction at a peeling speed of 300 mm / min with a universal tensile testing machine (manufactured by Orietec, RTM-100). Was measured as adhesive strength (N / 25 mm) (Measurement A). In addition, the adhesive sheet was bonded to each plate with a rubber roller in 23 ° C. × 60% RH, left in 60 ° C. × 60% RH for 3 days, returned to room temperature, and the same method as described above. The adhesive strength was measured (Measurement B).

[Shearing force]
A 25 mm-wide adhesive sheet was bonded to a stainless steel plate (SUS304BA) previously washed with toluene at 23 ° C. × 60% RH with a rubber roller so that the crimping area was 25 mm × 25 mm and left for 30 minutes. Then, the resistance when the sample was peeled in the shear direction at a peeling speed of 300 mm / min was measured as a shear force (N / 25 mm × 25 mm) with a universal tensile tester (manufactured by Orietec, RTM-100). . From the point of adhesiveness under stress to the adherend, the shearing force is preferably 100 to 400 N / 25 mm × 25 mm, more preferably 100 to 200 N / 25 mm × 25 mm.

[Retention force]
According to JIS Z-0237, the displacement distance (mm) after 60 minutes was measured under the conditions of a measurement temperature of 40 ° C. and a hanging load of 1 kg. From the viewpoint of adhesiveness under stress to the adherend, the holding force is preferably 0 to 2 mm, more preferably 0 to 0.3 mm.

[Adhesive residue on adherend]
Adhesive sheets were attached to polycarbonate substrates (PC plates), polystyrene plates (PS plates), and steel plates (zinc steel plates), respectively, and adhered at 60 ° C. × 60% RH for 5 days (measurement C) and 20 days ( Measurement D) After leaving to stand, after returning to room temperature (23 ° C.), the pressure-sensitive adhesive sheet was peeled off by human hand, and whether the pressure-sensitive adhesive was peeled off from the adherend during peeling was visually observed and judged according to the following criteria. In addition, the adhesive sheets were respectively attached to the adherends, left at 60 ° C. × 90% RH for 5 days (measurement E) and 20 days (measurement F), and then returned to room temperature (23 ° C.). The adhesive residue was determined in the same manner as described above. In addition, an adhesive sheet is attached to each of the adherends, left at 60 ° C. × 90% RH for 3 days, then left at 0 ° C. for 3 days, and then at 0 ° C. as above. The adhesive residue was determined by the method (Measurement G).
○: No peeling of adhesive was observed on the adherend.
(Triangle | delta): The peeling residue of an adhesive is slightly recognized by a to-be-adhered body.
X: Many peeling residues of the adhesive are observed on the adherend.

The adhesive tape for temporarily fixing and fixing an article according to the present invention can be used to cover an article such as an internal part or door of an article when packing the article as an adherend when the article such as an electric appliance or OA equipment is shipped. It is preferably used for temporarily fixing a fixing portion (for example, a printed steel plate or a resin plate).

Claims (5)

In the pressure-sensitive adhesive tape for temporarily fixing the article, having an adhesive layer on one side of the substrate,
The substrate is a uniaxially stretched polypropylene film,
Acrylic copolymer emulsion and oxazoline group-containing aqueous system obtained from a monomer mixture in which the pressure-sensitive adhesive layer is mainly composed of an alkyl (meth) acrylate having an alkyl group having 4 to 12 carbon atoms and containing methacrylic acid It is formed with an acrylic emulsion-type pressure-sensitive adhesive containing a crosslinking agent,
A pressure-sensitive adhesive tape for temporarily fixing an article, comprising an undercoat layer formed of a solvent-type amino group-grafted acrylic resin between the substrate and the pressure-sensitive adhesive layer.   The pressure-sensitive adhesive tape for temporarily fixing an article according to claim 1, wherein the monomer mixture further contains (meth) acrylonitrile.   3. The article according to claim 1, wherein the monomer mixture is mainly composed of an alkyl (meth) acrylate having 4 to 7 carbon atoms in the alkyl group and an alkyl (meth) acrylate having 8 to 12 carbon atoms in the alkyl group. Adhesive tape for temporarily fixing.   The pressure-sensitive adhesive tape for temporarily fixing an article according to any one of claims 1 to 3, wherein the acrylic copolymer in the acrylic copolymer emulsion has a weight average molecular weight of 100,000 to 500,000. A temporarily fixed article in which the article is temporarily fixed by the adhesive tape for temporarily fixing the article according to any one of claims 1 to 4.