JP5975775B2 - Adhesive - Google Patents

Description

  The present invention relates to an adhesive. The pressure-sensitive adhesive of the present invention has excellent initial reworkability when adhered to an adherend and excellent adhesion reliability after aging. Moreover, this invention relates to the adhesive sheet which has an adhesive layer which consists of such an adhesive on the at least single side | surface of a base material layer. Moreover, this invention relates to the surface protection film which has the adhesive layer which consists of such an adhesive on the single side | surface of a base material layer. The pressure-sensitive adhesive sheet of the present invention is preferably used, for example, for applications in which various members such as optical members and electronic members are adhesively fixed. The surface protective film of the present invention is preferably used for, for example, an application of protecting the surface by sticking to the surface of an optical member or an electronic member.

  LCDs, organic EL, touch panels using these, lens parts of cameras, optical members and electronic members such as electronic devices are generally exposed to prevent scratches on the surface during processing, assembly, inspection, transportation, etc. A surface protective film is attached to the surface side. Such a surface protective film is peeled off from the optical member or the electronic member when the surface protection is no longer necessary.

  When the surface protective film is attached manually, air bubbles may be caught between the adherend and the surface protective film. For this reason, some techniques which improve the wettability of a surface protection film are reported so that a bubble may not be involved in the case of sticking. For example, a surface protective film using a silicone resin having a high wetting speed as an adhesive layer is known. However, when silicone resin is used for the pressure-sensitive adhesive layer, the pressure-sensitive adhesive component easily contaminates the adherend, and surface protection for protecting the surface of members that require particularly low contamination such as optical members and electronic members. There are problems in using it as a film.

  As a surface protective film with little contamination derived from the pressure-sensitive adhesive component, a surface protective film using an acrylic resin for the pressure-sensitive adhesive layer is known. However, the surface protective film using acrylic resin for the adhesive layer is inferior in wettability, so when sticking the surface protective film manually, air bubbles are involved between the adherend and the surface protective film. There is. In addition, when an acrylic resin is used for the adhesive layer, there is a problem that glue residue is likely to be generated at the time of peeling, and a surface protection film for protecting the surface of a member that is particularly apt to be mixed with foreign substances such as an optical member and an electronic member. There is a problem to use as.

  Recently, a surface protective film using a polyurethane-based resin as an adhesive layer has been reported as a surface protective film that can achieve both excellent wettability, low contamination, and reduced glue residue (see, for example, Patent Document 1).

  Here, depending on a use, when sticking a surface protection film to a to-be-adhered body by hand, the outstanding initial rework property is requested | required with the outstanding wettability. The surface protective film attached to the adherend may need to be peeled off immediately after sticking for correction of misalignment, etc. In this case, it can be peeled lightly without deformation, and then It is required to be able to re-adhere well without entrainment of bubbles. Also, in applications where re-peeling does not occur frequently after re-sticking as described above, it is necessary to have excellent adhesion reliability after elapse of time in order to avoid troubles that easily peel off.

  In view of the above, there is a demand for a pressure-sensitive adhesive containing a polyurethane-based resin that has excellent initial reworkability when adhered to an adherend and excellent adhesion reliability after aging. Moreover, if an adhesive sheet using such an adhesive can be provided, it is effective, for example, for use in adhesively fixing various members such as an optical member and an electronic member. Furthermore, if a surface protective film using such a pressure-sensitive adhesive can be provided, it is effective, for example, for use in protecting the surface by sticking to the surface of an optical member or an electronic member.

JP 2006-18295 A

  The subject of this invention is providing the adhesive containing a polyurethane-type resin which is excellent in initial stage rework property, and excellent in the adhesive reliability after time, when it adheres to a to-be-adhered body. Moreover, the subject of this invention is providing the adhesive sheet and surface protection film which have an adhesive layer which consists of such an adhesive. Furthermore, the subject of this invention is providing the optical member and electronic member to which such an adhesive sheet and a surface protection film were stuck.

The pressure-sensitive adhesive of the present invention is
A pressure-sensitive adhesive containing a polyurethane resin,
When the initial adhesive force immediately after sticking to the acrylic plate is A, and the adhesive strength after 70 ° C. × 1 day after sticking to the acrylic plate is B,
The initial adhesive strength A is 0.001 N / 20 mm to 2.0 N / 20 mm,
The adhesive strength B after 1 day at 70 ° C. is 2.0 times or more of the initial adhesive strength A.

  In a preferred embodiment, the polyurethane resin is a polyurethane resin obtained by curing a composition containing a polyol (A) having two or more OH groups and a polyfunctional isocyanate compound (B).

  In a preferred embodiment, the polyol (A) is two or more kinds of polyols.

  In a preferred embodiment, the two or more types of polyol are at least one type of polyol having two OH groups, and at least one type of polyol having three or more OH groups.

  In a preferred embodiment, the polyol having two OH groups has a number average molecular weight Mn of 6000 or more, and the polyol having three or more OH groups has a number average molecular weight Mn of 2,000 or more.

  In a preferred embodiment, the polyol having two OH groups has a number average molecular weight Mn of less than 6000, the polyol having three or more OH groups has a number average molecular weight Mn of less than 2000, and the polyol (A) And the equivalent ratio of NCO group to OH group in the polyfunctional isocyanate compound (B) is less than 1.3 as NCO group / OH group.

  In a preferred embodiment, the polyol (A) contains 50% by weight or more of a polyol having two OH groups.

  In preferable embodiment, the usage-amount of the catalyst (C) used in order to obtain the said polyurethane-type resin by hardening is 0.01 weight part or more with respect to 100 weight part of said polyol (A).

  The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention on at least one surface of the base material layer.

  The optical member of the present invention is obtained by sticking the pressure-sensitive adhesive sheet of the present invention.

  The electronic member of the present invention is obtained by attaching the pressure-sensitive adhesive sheet of the present invention.

  The surface protective film of this invention has the adhesive layer which consists of an adhesive of this invention in the single side | surface of a base material layer.

  In preferable embodiment, the surface protection film of this invention is used for the surface protection of an optical member or an electronic member.

  The optical member of the present invention has the surface protective film of the present invention attached thereto.

  The electronic member of the present invention is obtained by attaching the surface protective film of the present invention.

  ADVANTAGE OF THE INVENTION According to this invention, when sticking to a to-be-adhered body, while being excellent in initial stage rework property, the adhesive containing a polyurethane-type resin which is excellent in the adhesive reliability after time can be provided. Moreover, the adhesive sheet and surface protection film which have an adhesive layer which consists of such an adhesive can be provided. Furthermore, an optical member or an electronic member to which such an adhesive sheet or a surface protective film is attached can be provided.

It is a schematic sectional drawing of the surface protection film by preferable embodiment of this invention.

≪A. Adhesive >>
The pressure-sensitive adhesive of the present invention contains a polyurethane resin as a main component. The content of the polyurethane resin in the pressure-sensitive adhesive of the present invention is preferably 90% to 100% by weight, more preferably 95% to 100% by weight, and still more preferably 98% to 100% by weight. It is. Only one type of adhesive may be used, or two or more types may be used.

  The pressure-sensitive adhesive of the present invention has an initial pressure-sensitive adhesive force A of 0.001 N / 20 mm to 2.0 N / 20 mm, preferably 0.005 N / 20 mm to 1.8 N / 20 mm, more preferably 0.01 N / 20 mm to 1.5 N / 20 mm, particularly preferably 0.1 N / 20 mm to 1.3 N / 20 mm, most preferably 0.15 N. / 20 mm to 1.0 N / 20 mm. When the initial adhesive strength A is within the above range, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend. The measurement of the initial adhesive strength A will be described later.

  When the pressure-sensitive adhesive of the present invention is attached to an acrylic plate and the adhesive strength after 70 ° C. × 1 day is defined as B, the adhesive strength B after 70 ° C. × 1 day is preferably 0.1 N / 20 mm or more. More preferably, it is 0.5 N / 20 mm or more, further preferably 1.0 N / 20 mm or more, and particularly preferably 1.5 N / 20 mm or more. The upper limit of the adhesive strength B after 70 ° C. × 1 day is preferably 10 N / 20 mm or less. When the pressure-sensitive adhesive force B after 70 ° C. × 1 day is within the above range, the pressure-sensitive adhesive of the present invention is excellent in adhesion reliability after lapse of time when adhered to an adherend. The measurement of the adhesive strength B after 70 ° C. × 1 day will be described later.

  In the pressure-sensitive adhesive of the present invention, the adhesive strength B after 70 ° C. × 1 day is 2.0 times or more of the initial adhesive strength A, preferably 3.0 times or more, more preferably 4.0 times or more. It is particularly preferably 5.0 times or more, and most preferably 10 times or more. The upper limit of the magnification of the adhesive strength B after 70 ° C. × 1 day to the initial adhesive strength A is preferably 100 times or less. When the adhesive strength B after 70 ° C. × 1 day with respect to the initial adhesive strength A is within the above range, the adhesive of the present invention has an adhesive reliability after lapse of time when adhered to an adherend. Excellent in properties. The measurement of the adhesive strength B after 70 ° C. × 1 day will be described later.

  The polyurethane resin is preferably obtained by curing a composition containing a polyol (A) having two or more OH groups and a polyfunctional isocyanate compound (B). By adopting such a polyurethane-based resin, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. Moreover, by adopting such a polyurethane-based resin, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue.

  Only one type of polyol (A) may be used, or two or more types may be used. Preferably, the polyol (A) is two or more kinds of polyols. When the polyol (A) is two or more kinds of polyols, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. Moreover, when the polyol (A) is two or more kinds of polyols, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue.

  The polyol (A) is preferably two or more kinds of polyols. In this case, the two or more kinds of polyols are preferably polyols having at least one kind having two OH groups, and at least one kind thereof. Is a polyol having 3 or more OH groups. By adopting such a polyol (A), the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. Moreover, by adopting such a polyol (A), the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduction of glue residue.

  The polyol having two OH groups that can be contained in the polyol (A) has a number average molecular weight Mn of preferably 6000 or more, more preferably 7000 or more, further preferably 8000 or more, particularly preferably. 9000 or more. The upper limit of the number average molecular weight Mn is preferably 20000 or less. By adjusting the number average molecular weight Mn of the polyol having two OH groups that can be contained in the polyol (A) within the above range, the pressure-sensitive adhesive of the present invention has an initial reworkability when adhered to an adherend. In addition to excellent adhesion reliability after aging. Moreover, by adjusting the number average molecular weight Mn of the polyol having two OH groups that can be contained in the polyol (A) within the above range, the pressure-sensitive adhesive of the present invention has excellent wettability, low contamination, paste residue. Reduction can be achieved at the same time.

  The polyol having three or more OH groups that can be contained in the polyol (A) has a number average molecular weight Mn of preferably 2000 or more, more preferably 2500 or more, still more preferably 3000 or more, particularly preferably. Is 3500 or more. The upper limit of the number average molecular weight Mn is preferably 20000 or less. By adjusting the number average molecular weight Mn of the polyol having 3 or more OH groups that can be contained in the polyol (A) within the above range, the pressure-sensitive adhesive of the present invention is subjected to initial reworking when it is attached to an adherend. In addition to excellent properties, the adhesive reliability after time is excellent. In addition, by adjusting the number average molecular weight Mn of the polyol having three or more OH groups that can be contained in the polyol (A) within the above range, the pressure-sensitive adhesive of the present invention has excellent wettability, low contamination, and paste. It is possible to reduce waste.

  The polyol (A) contains a polyol having two OH groups, preferably 50% by weight or more, more preferably 55% by weight or more, further preferably 60% by weight or more, and further preferably 62% by weight. It is contained more preferably, more preferably 65% by weight or more, most preferably 67% by weight or more. By adopting such a polyol (A), the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. Moreover, by adopting such a polyol (A), the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduction of glue residue.

  Examples of the polyol (A) include polyester polyol, polyether polyol, polycaprolactone polyol, polycarbonate polyol, castor oil-based polyol, and the like.

  The polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

  Examples of the polyol component include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 2-butyl-2-ethyl-1. , 3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2-methyl Examples include -1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, and polypropylene glycol.

  Examples of the acid component include succinic acid, methyl succinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, 2-methyl-1, 4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4′-biphenyldicarboxylic acid , And these acid anhydrides.

  Examples of polyether polyols include water, low molecular weight polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzenes (catechol, resorcin, hydroquinone, etc.), etc. And polyether polyols obtained by addition polymerization of alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

  Examples of the polycaprolactone polyol include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

  Examples of the polycarbonate polyol include a polycarbonate polyol obtained by polycondensation reaction of the polyol component and phosgene; the polyol component, dimethyl carbonate, diethyl carbonate, diprovir carbonate, diisopropyl carbonate, dibutyl carbonate, ethyl butyl carbonate, ethylene carbonate, Polycarbonate polyol obtained by ester exchange condensation with carbonic acid diesters such as propylene carbonate, diphenyl carbonate and dibenzyl carbonate; copolymerized polycarbonate polyol obtained by using two or more of the above polyol components in combination; Polycarbonate polyol obtained by esterification reaction with a compound; the above-mentioned various polycarbonate polyols and a hydroxyl group-containing compound A polycarbonate polyol obtained by a reaction of tellurization; a polycarbonate polyol obtained by a transesterification reaction between the above various polycarbonate polyols and an ester compound; a polycarbonate polyol obtained by a transesterification reaction between the various polycarbonate polyols and a hydroxyl group-containing compound; And polyester polycarbonate polyols obtained by polycondensation reaction of the various polycarbonate polyols with dicarboxylic acid compounds; copolymer polyether polycarbonate polyols obtained by copolymerizing the various polycarbonate polyols and alkylene oxides;

  An example of the castor oil-based polyol is a castor oil-based polyol obtained by reacting a castor oil fatty acid with the polyol component. Specific examples include castor oil-based polyols obtained by reacting castor oil fatty acid with polypropylene glycol.

  One type of polyfunctional isocyanate compound (B) may be sufficient, and two or more types may be sufficient as it.

  As the polyfunctional isocyanate compound (B), any appropriate polyfunctional isocyanate compound that can be used in the urethanization reaction can be adopted. Examples of such a polyfunctional isocyanate compound (B) include polyfunctional aliphatic isocyanate compounds, polyfunctional alicyclic isocyanate compounds, polyfunctional aromatic isocyanate compounds, and the like.

  Examples of the polyfunctional aliphatic isocyanate compound include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4 Examples include 4-trimethylhexamethylene diisocyanate.

  Examples of the polyfunctional alicyclic isocyanate compound include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, Examples include hydrogenated tolylene diisocyanate and hydrogenated tetramethylxylylene diisocyanate.

  Examples of the polyfunctional aromatic diisocyanate compound include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2′-didiphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

  Examples of the polyfunctional isocyanate compound (B) include trimethylolpropane adducts of various polyfunctional isocyanate compounds as described above, burettes reacted with water, and trimers having an isocyanurate ring. These may be used in combination.

  As the polyfunctional isocyanate compound (B), a polyfunctional aromatic diisocyanate compound is preferable. By employing a polyfunctional aromatic diisocyanate compound as the polyfunctional isocyanate compound (B), whitening of the resulting pressure-sensitive adhesive can be suppressed, and high transparency can be imparted. If high transparency can be imparted to the pressure-sensitive adhesive of the present invention, it becomes possible to increase the transparency of the surface protection film of the present invention having a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention. Inspection or the like can be accurately performed in a state of being attached to the surface of the member or the electronic member.

  The polyurethane-based resin is preferably obtained by curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B). Such a composition may contain any appropriate other component other than the polyol (A) and the polyfunctional isocyanate compound (B) as long as the effects of the present invention are not impaired. Examples of such other components include catalysts, other resin components other than polyurethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, plasticizers, Examples thereof include an anti-aging agent, a conductive agent, an ultraviolet absorber, an antioxidant, a light stabilizer, a surface lubricant, a leveling agent, a corrosion inhibitor, a heat stabilizer, a polymerization inhibitor, a lubricant, and a solvent.

  The weight ratio of the polyol (A) and the polyfunctional isocyanate compound (B) is preferably 30 parts by weight or less, more preferably 28 parts by weight, based on 100 parts by weight of the polyol (A). It is not more than parts by weight, more preferably not more than 25 parts by weight, particularly preferably not more than 23 parts by weight. The lower limit of the weight ratio of the polyfunctional isocyanate compound (B) is preferably 5 parts by weight or more for the polyfunctional isocyanate compound (B) with respect to 100 parts by weight of the polyol (A). By adjusting the weight ratio of the polyol (A) and the polyfunctional isocyanate compound (B) within the above range, the pressure-sensitive adhesive of the present invention has excellent initial reworkability when adhered to an adherend, Excellent adhesion reliability later. Moreover, by adjusting the weight ratio of the polyol (A) and the polyfunctional isocyanate compound (B) within the above range, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduction of glue residue. .

  In the polyol (A) and the polyfunctional isocyanate compound (B), the equivalent ratio of the NCO group to the OH group is preferably 0.1 to 5.0, more preferably 0.2 to NCO group / OH group. 4.0, more preferably 0.3 to 3.0. By adjusting the equivalent ratio of NCO group / OH group within the above range, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend, and in adhesive reliability after aging. Excellent. Moreover, by adjusting the equivalent ratio of NCO group / OH group within the above range, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue. In the case where a polyol having two OH groups having a number average molecular weight Mn of less than 6000 and a polyol having three or more OH groups having a number average molecular weight Mn of less than 2,000 are used in combination as the polyol (A), an NCO group The equivalent ratio of OH groups to NOH groups / OH groups is preferably less than 1.3, more preferably 0.1 to 1.2, still more preferably 0.1 to 1.1, Most preferably, it is 0.1-1.0. When the polyol (A) is used in combination with a polyol having two OH groups having a number average molecular weight Mn of less than 6000 and a polyol having three or more OH groups having a number average molecular weight Mn of less than 2000, NCO groups / OH By adjusting the equivalent ratio of the groups within the above range, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. Further, when the polyol (A) is used in combination with a polyol having two OH groups having a number average molecular weight Mn of less than 6000 and a polyol having three or more OH groups having a number average molecular weight Mn of less than 2000, an NCO group By adjusting the equivalent ratio of / OH group within the above range, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue.

  As a method for obtaining a polyurethane resin by curing a composition containing a polyol (A) and a polyfunctional isocyanate compound (B), the effects of the present invention, such as a urethanization reaction method using bulk polymerization or solution polymerization, are used. Any appropriate method can be adopted as long as it is not impaired.

  In order to cure the composition containing the polyol (A) and the polyfunctional isocyanate compound (B), the catalyst (C) is preferably used. Examples of such a catalyst (C) include organometallic compounds and tertiary amine compounds.

  Examples of organometallic compounds include iron compounds, tin compounds, titanium compounds, zirconium compounds, lead compounds, cobalt compounds, zinc compounds, and the like. Among these, an iron-based compound is preferable in terms of high reactivity.

  Examples of iron-based compounds include iron acetylacetonate and iron 2-ethylhexanoate.

  Examples of tin compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin maleate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin sulfide, tributyltin methoxide, tributyltin acetate, triethyltin ethoxide, Examples include tributyltin ethoxide, dioctyltin oxide, dioctyltin dilaurate, tributyltin chloride, tributyltin trichloroacetate, and tin 2-ethylhexanoate.

  Examples of titanium compounds include dibutyltitanium dichloride, tetrabutyltitanate, butoxytitanium trichloride, and the like.

  Examples of the zirconium-based compound include zirconium naphthenate and zirconium acetylacetonate.

  Examples of the lead-based compound include lead oleate, lead 2-ethylhexanoate, lead benzoate, lead naphthenate, and the like.

  Examples of the cobalt-based compound include cobalt 2-ethylhexanoate and cobalt benzoate.

  Examples of the zinc-based compound include zinc naphthenate and zinc 2-ethylhexanoate.

  Examples of the tertiary amine compound include triethylamine, triethylenediamine, 1,8-diazabixic mouth- (5,4,0) -undecene-7, and the like.

  Only one type of catalyst (C) may be used, or two or more types may be used. The amount of the catalyst (C) used is preferably 0.01 parts by weight or more, more preferably 0.08 parts by weight or more, and further preferably 0.1 parts by weight with respect to 100 parts by weight of the polyol (A). Part or more, particularly preferably 0.15 part by weight or more. The upper limit of the amount of catalyst (C) used is preferably 5 parts by weight or less. By adjusting the amount of the catalyst (C) used within the above range, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. . Moreover, by adjusting the amount of the catalyst (C) within the above range, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue. As the polyol (A), when a polyol having two OH groups having a number average molecular weight Mn of less than 6000 and a polyol having three or more OH groups having a number average molecular weight Mn of less than 2,000 are used in combination, By adjusting the amount of the catalyst (C) used within the above range, the pressure-sensitive adhesive of the present invention is excellent in initial reworkability when adhered to an adherend and excellent in adhesion reliability after aging. . When the polyol (A) is used in combination with a polyol having two OH groups having a number average molecular weight Mn of less than 6000 and a polyol having three or more OH groups having a number average molecular weight Mn of less than 2,000, By adjusting the amount of the catalyst (C) within the above range, the pressure-sensitive adhesive of the present invention can achieve both excellent wettability, low contamination, and reduced glue residue.

  The pressure-sensitive adhesive of the present invention may contain any appropriate other component in addition to the polyurethane resin as described above as long as the effects of the present invention are not impaired. Examples of such other components include other resin components other than polyurethane resins, tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, plasticizers, and anti-aging agents. Agents, conductive agents, ultraviolet absorbers, antioxidants, light stabilizers, surface lubricants, leveling agents, corrosion inhibitors, heat stabilizers, polymerization inhibitors, lubricants, solvents and the like.

  The pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention can be formed by any appropriate method. Such a pressure-sensitive adhesive layer can be obtained by applying a pressure-sensitive adhesive material on any suitable support to form a pressure-sensitive adhesive. In this case, the member that becomes the base layer of the surface protective film may be used as a support, and the pressure-sensitive adhesive formed by forming on any other appropriate support is finally used as the surface protective film. It is good also as an adhesive layer by transferring on the member used as a base material layer.

  Examples of the method for applying the adhesive material include roll coating, gravure coating, reverse coating, roll brushing, spray coating, air knife coating, extrusion coating using a die coater, and the like.

≪B. Adhesive sheet and surface protective film >>
The pressure-sensitive adhesive sheet of the present invention has a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention on at least one surface of the base material layer. The surface protective film of this invention has the adhesive layer which consists of an adhesive of this invention in the single side | surface of a base material layer. The pressure-sensitive adhesive sheet of the present invention is preferably used, for example, for applications in which various members such as optical members and electronic members are adhesively fixed. The surface protective film of the present invention is preferably used for, for example, an application of protecting the surface by sticking to the surface of an optical member or an electronic member.

  As the thickness of the pressure-sensitive adhesive layer, any appropriate thickness can be adopted depending on the application. The thickness of the pressure-sensitive adhesive layer is preferably 1 μm to 100 μm, more preferably 3 μm to 50 μm, and further preferably 5 μm to 30 μm.

  FIG. 1 is a schematic cross-sectional view of an adhesive sheet or a surface protective film according to a preferred embodiment of the present invention. The pressure-sensitive adhesive sheet or surface protective film 10 includes a base material layer 1 and a pressure-sensitive adhesive layer 2. The pressure-sensitive adhesive sheet or the surface protective film of the present invention may further have any appropriate other layer as necessary (not shown).

  The pressure-sensitive adhesive sheet of the present invention may have a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive of the present invention on both surfaces of the base material layer. That is, in FIG. 1, a pressure-sensitive adhesive layer may be further provided on the side opposite to the pressure-sensitive adhesive layer 2 of the base material layer 1.

  If there is a surface of the base material layer 1 to which the pressure-sensitive adhesive layer 2 is not attached, for example, a fatty acid is added to the base material layer for the purpose of forming a wound body that can be easily rewound. Perform release treatment by adding amide, polyethyleneimine, long-chain alkyl additives, etc., or provide a coat layer made of any appropriate release agent such as silicone-based, long-chain alkyl-based, fluorine-based, etc. Can do.

  The pressure-sensitive adhesive sheet and the surface protective film of the present invention may be bonded with a release liner having releasability.

  The thickness of the pressure-sensitive adhesive sheet and the surface protective film of the present invention can be set to any appropriate thickness depending on the application. From the viewpoint of sufficiently expressing the effects of the present invention, the thickness is preferably 10 μm to 300 μm, more preferably 15 μm to 250 μm, still more preferably 20 μm to 200 μm, and particularly preferably 25 μm to 150 μm.

  The pressure-sensitive adhesive sheet and the surface protective film of the present invention preferably have high transparency. Due to the high transparency of the pressure-sensitive adhesive sheet and the surface protective film of the present invention, it is possible to accurately inspect the surface of the optical member or the electronic member while it is adhered. In the pressure-sensitive adhesive sheet and the surface protective film of the present invention, the haze is preferably 5% or less, more preferably 4% or less, still more preferably 3% or less, and particularly preferably 2% or less. Preferably it is 1% or less.

  Any appropriate thickness can be adopted as the thickness of the base material layer depending on the application. The thickness of the base material layer is preferably 5 μm to 300 μm, more preferably 10 μm to 250 μm, still more preferably 15 μm to 200 μm, and particularly preferably 20 μm to 150 μm.

  The base material layer may be a single layer or a laminate of two or more layers. The base material layer may be stretched.

  Any appropriate material can be adopted as the material of the base material layer depending on the application. For example, a plastic, paper, a metal film, a nonwoven fabric, etc. are mentioned. Preferably, it is a plastic. The base material layer may be composed of one kind of material, or may be composed of two or more kinds of materials. For example, you may be comprised from 2 or more types of plastics.

  Examples of the plastic include a polyester resin, a polyamide resin, and a polyolefin resin. Examples of the polyester resin include polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Examples of the polyolefin resin include olefin monomer homopolymers, olefin monomer copolymers, and the like. Specific examples of polyolefin resins include homopolypropylene; block-type, random-type, and graft-type propylene copolymers having an ethylene component as a copolymer component; reactor TPO; low density, high density, linear Low density, ultra-low density, etc. ethylene polymers; ethylene / propylene copolymer, ethylene / vinyl acetate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / acrylic acid And ethylene copolymers such as butyl copolymer, ethylene / methacrylic acid copolymer, and ethylene / methyl methacrylate copolymer.

  The base material layer may contain any appropriate additive as required. Examples of the additive that can be contained in the base material layer include an antioxidant, an ultraviolet absorber, a light stabilizer, an antistatic agent, a filler, and a pigment. The kind, number, and amount of additives that can be contained in the base material layer can be appropriately set according to the purpose. In particular, when the material of the base material layer is plastic, it is preferable to contain some of the above additives for the purpose of preventing deterioration. From the viewpoint of improving weather resistance and the like, particularly preferred additives include antioxidants, ultraviolet absorbers, light stabilizers, and fillers.

  Any appropriate antioxidant can be adopted as the antioxidant. Examples of such antioxidants include phenol-based antioxidants, phosphorus-based processing heat stabilizers, lactone-based processing heat stabilizers, sulfur-based heat-resistant stabilizers, phenol-phosphorus-based antioxidants, and the like. The content of the antioxidant is preferably 1 part by weight or less with respect to 100 parts by weight of the base resin of the base layer (when the base layer is a blend, the blend is the base resin), More preferably, it is 0.5 weight part or less, More preferably, it is 0.01 weight part-0.2 weight part.

  Arbitrary appropriate ultraviolet absorbers can be employ | adopted as a ultraviolet absorber. Examples of such UV absorbers include benzotriazole UV absorbers, triazine UV absorbers, and benzophenone UV absorbers. The content of the ultraviolet absorber is preferably 2 parts by weight or less with respect to 100 parts by weight of the base resin forming the base layer (when the base layer is a blend, the blend is the base resin). More preferably 1 part by weight or less, still more preferably 0.01 part by weight to 0.5 part by weight.

  Any appropriate light stabilizer can be adopted as the light stabilizer. Examples of such light stabilizers include hindered amine light stabilizers and benzoate light stabilizers. The content ratio of the light stabilizer is preferably 2 parts by weight or less with respect to 100 parts by weight of the base resin forming the base layer (in the case where the base layer is a blend, the blend is the base resin). More preferably 1 part by weight or less, still more preferably 0.01 part by weight to 0.5 part by weight.

  Any appropriate filler can be adopted as the filler. Examples of such fillers include inorganic fillers. Specific examples of the inorganic filler include carbon black, titanium oxide, and zinc oxide. The content of the filler is preferably 20 parts by weight or less with respect to 100 parts by weight of the base resin forming the base layer (when the base layer is a blend, the blend is the base resin). The amount is more preferably 10 parts by weight or less, and still more preferably 0.01 parts by weight to 10 parts by weight.

  Furthermore, as the additive, for the purpose of imparting antistatic properties, inorganic, low molecular weight and high molecular weight antistatic agents such as surfactants, inorganic salts, polyhydric alcohols, metal compounds, carbon and the like are also preferred. In particular, a high molecular weight antistatic agent and carbon are preferable from the viewpoint of contamination and adhesiveness maintenance.

  The pressure-sensitive adhesive sheet and the surface protective film of the present invention can be used for any appropriate application. The pressure-sensitive adhesive sheet of the present invention is preferably used, for example, for applications in which various members such as optical members and electronic members are adhesively fixed. The surface protective film of the present invention is preferably used for, for example, an application of protecting the surface by sticking to the surface of an optical member or an electronic member.

  The optical member to which the pressure-sensitive adhesive sheet of the present invention is attached can be bonded and peeled many times manually.

  The electronic member to which the pressure-sensitive adhesive sheet of the present invention is attached can be bonded and peeled many times manually.

  The optical member to which the surface protective film of the present invention is attached can be bonded and peeled many times manually.

  The electronic member to which the surface protective film of the present invention is attached can be bonded and peeled many times manually.

The pressure-sensitive adhesive sheet and the surface protective film of the present invention can be produced by any appropriate method. As such a manufacturing method, for example,
(1) A method of applying a solution or a hot melt of a pressure-sensitive adhesive layer forming material (for example, a composition containing a polyurethane resin) on a base material layer,
(2) A method of transferring the pressure-sensitive adhesive layer applied and formed in the form of a separator onto the base material layer according to that,
(3) A method of forming and applying the forming material of the pressure-sensitive adhesive layer onto the base material layer,
(4) A method of extruding a base material layer and an adhesive layer in two layers or multiple layers,
(5) A method of laminating a pressure-sensitive adhesive layer on a base material layer, or a method of laminating two pressure-sensitive adhesive layers together with a laminate layer,
(6) A method of laminating a pressure-sensitive adhesive layer and a base material layer forming material such as a film or a laminate layer in two or multiple layers,
It can be performed according to any appropriate production method.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all. In addition, the test and evaluation method in an Example etc. are as follows. Note that “parts” means “parts by weight” unless otherwise noted, and “%” means “% by weight” unless otherwise noted.

<Measurement of initial adhesive strength to acrylic plate>
The adhesive sheet or the surface protective film was cut into a width of 20 mm and a length of 100 mm to obtain a sample for evaluation.
In an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH, the pressure-sensitive adhesive layer surface of the sample for evaluation was attached to an acrylic plate (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Acrylite L) by one reciprocating 2.0 kg roller. After curing for 30 minutes in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH, peeling is performed at a peeling angle of 180 ° and a pulling speed of 300 mm / min using a universal tensile tester (manufactured by Minebea Co., Ltd., product name: TCM-1kNB). The adhesive strength was measured.

<Measurement of Adhesive Strength after 70 ° C. × 1 Day for Acrylic Plate>
A sample for evaluation was prepared by the same method as the initial adhesive strength for the acrylic plate, and the adhesive strength after storage at 70 ° C. for 1 day was measured by the same method as the initial adhesive strength.

<Evaluation of initial reworkability>
The adhesive sheet or the surface protective film was cut into a width of 20 mm and a length of 100 mm to obtain a sample for evaluation. In an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH, the pressure-sensitive adhesive layer surface of the sample for evaluation was attached to an acrylic plate (manufactured by Mitsubishi Rayon, trade name: Acrylite) by reciprocating a 2 kg roller.
After curing for 30 minutes in an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH, the end of the sample for evaluation is pinched by the evaluator's hand, the peeling angle is 100 to 120 ° in the direction of 100 mm in length, and the pulling speed is 100 mm / min. Peeling was performed at ˜500 mm / min, and deformation of the substrate was observed. Reworkability was evaluated according to the following criteria.
○: The substrate was not deformed and could be peeled off.
X: The substrate was deformed.

<Evaluation of adhesion reliability after time>
The pressure-sensitive adhesive sheet or surface protective film was cut into a width of 20 mm and a length of 50 mm to obtain a sample for evaluation. In an atmosphere of a temperature of 23 ° C. and a humidity of 50% RH, an evaluation sample was applied to an acrylic plate (product name: Acrylite L, manufactured by Mitsubishi Rayon Co., Ltd.) obtained by cutting the adhesive layer surface of the evaluation sample into a width of 25 mm and a length of 200 mm. Along with the length direction of the acrylic plate, the 2 kg roller was attached by one reciprocation.
After storage at 70 ° C. for 1 day, the sample is left for 30 minutes in an atmosphere at a temperature of 23 ° C. and a humidity of 50% RH, and then the length is such that the evaluation sample exists inside the curved acrylic plate with the evaluation sample attached. It attached to the jig | tool fixed to 190 mm width, and the floating of the adhesion surface of the sample for evaluation and an acrylic board was observed. According to the following criteria, the adhesion reliability after aging was evaluated.
○: There is no float on the adhesion surface of the sample for evaluation and the acrylic plate.
X: Floating occurred on the adhesion surface between the sample for evaluation and the acrylic plate.

<Evaluation of wettability>
The surface protective film was cut into 2.5 cm × 10.0 cm to obtain a test piece. By hand, the test piece was bonded to an acrylic plate (trade name: Acrylite L, manufactured by Mitsubishi Rayon Co., Ltd.) at a speed of 10 m / min, and the presence or absence of bubbles between the test piece and the acrylic plate was confirmed. Evaluation was performed according to the following criteria.
○: No bubbles.
(Triangle | delta): Although a bubble is slightly involved, it can remove easily.
X: A large number of bubbles are involved, and the bubbles cannot be easily removed.

<Evaluation of transparency>
Using a haze meter HM-150 (manufactured by Murakami Color Research Laboratory Co., Ltd.), in accordance with JIS-K-7136, haze (%) = (Td / Tt) × 100 (Td: diffuse transmittance, Tt: all Light transmittance). Transparency was evaluated according to the following criteria.
○: Haze is 3% or less.
X: Haze exceeds 3%.

[Example 1]
As the polyol (A), Preminol S4006 (manufactured by Asahi Glass Co., Ltd., Mn = 5500) which is a polyol having two OH groups: 70 parts by weight, Sanniks GP-1500 (Sanyo Chemical Co., Ltd.) which is a polyol having three OH groups EDP-1100 (manufactured by ADEKA Co., Ltd., Mn = 1100): 12 parts by weight, trimethylolpropane as a polyfunctional isocyanate compound (B), manufactured by company, Mn = 1500): 18 parts by weight, polyol having 4 OH groups / Tolylene diisocyanate trimer adduct (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate L): 12 parts by weight, catalyst (manufactured by Nippon Chemical Industry Co., Ltd., trade name: Nursem Ferric): 0.05 weight And ethyl acetate as a diluent solvent so that the solid content concentration is 50% by weight. And 拌 to give a urethane-based pressure-sensitive adhesive composition. The obtained urethane-based pressure-sensitive adhesive composition was applied to a base material “Lumirror S10” (thickness 38 μm, manufactured by Toray Industries, Inc.) made of a polyester resin so that the thickness after drying with a fountain roll was 10 μm. It was cured and dried under the condition of a drying time of 30 seconds.
Next, the surface of the pressure-sensitive adhesive layer is covered with a release film surface-treated with a release agent, left at a temperature of 50 ° C. for 12 hours, and then left at room temperature (25 ° C.) for 1 hour to obtain a surface protective film (1). It was. In addition, the obtained surface protection film (1) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

[Example 2]
A surface protective film (2) having an adhesive layer was prepared in the same manner as in Example 1 except that the amount of the polyfunctional isocyanate compound (B) used was 24 parts by weight (NCO group / OH group = 1.0). Obtained. In addition, the obtained surface protection film (2) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

Example 3
As the polyol (A), Preminol S4006 (manufactured by Asahi Glass Co., Ltd., Mn = 5500) which is a polyol having two OH groups: 70 parts by weight, Sanniks GP-1500 (Sanyo Chemical Co., Ltd.) which is a polyol having three OH groups Company, Mn = 1500): 30 parts by weight, the amount of polyfunctional isocyanate compound (B) used is 30 parts by weight (NCO group / OH group = 1.3), and the amount of catalyst used is 0.1 weight. A surface protective film (3) having a pressure-sensitive adhesive layer was obtained in the same manner as in Example 1 except that the part was used. In addition, the obtained surface protection film (3) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

Example 4
As the polyol (A), Preminol S4011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000) which is a polyol having two OH groups: 75 parts by weight, Sanniks GP-5000 (Sanyo Chemical Co., Ltd.) which is a polyol having three OH groups Company, Mn = 5000): 25 parts by weight, the amount of polyfunctional isocyanate compound (B) used is 13 parts by weight (NCO group / OH group = 2.0), and the amount of catalyst used is 0.6% by weight. A surface protective film (4) having a pressure-sensitive adhesive layer was obtained in the same manner as in Example 1 except that the part was used. In addition, the obtained surface protection film (4) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

Example 5
As the polyol (A), Preminol S4011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000) which is a polyol having two OH groups: 50 parts by weight, Sanniks GP-5000 (Sanyo Chemical Co., Ltd.) which is a polyol having three OH groups Company, Mn = 5000): 50 parts by weight, the amount of polyfunctional isocyanate compound (B) used is 17 parts by weight (NCO group / OH group = 2.0), and the amount of catalyst used is 0.8 weight. A surface protective film (5) having a pressure-sensitive adhesive layer was obtained in the same manner as in Example 1 except that the part was made a part. In addition, the obtained surface protection film (5) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

Example 6
As the polyol (A), Preminol S4011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000) which is a polyol having two OH groups: 25 parts by weight, Sanniks GP-5000 (Sanyo Chemical Co., Ltd.) which is a polyol having three OH groups Made by company, Mn = 5000): 75 parts by weight, the amount of polyfunctional isocyanate compound (B) used is 22 parts by weight (NCO group / OH group = 2.0), and the amount of catalyst used is 1.0 weight. A surface protective film (6) having a pressure-sensitive adhesive layer was obtained in the same manner as in Example 1 except that the part was made a part. In addition, the obtained surface protection film (6) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

[Comparative Example 1]
A surface protective film (C1) having an adhesive layer was prepared in the same manner as in Example 1 except that the amount of the polyfunctional isocyanate compound (B) used was 30 parts by weight (NCO group / OH group = 1.3). Obtained. In addition, the obtained surface protection film (C1) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

[Comparative Example 2]
As the polyol (A), preminol S4011 (manufactured by Asahi Glass Co., Ltd., Mn = 10000), which is a polyol having two OH groups, is used in an amount of 100 parts by weight, and the amount of the polyfunctional isocyanate compound (B) used is 4.4 parts by weight. (NCO group / OH group = 1.0), except that the amount of the catalyst used was 0.39 parts by weight. The surface protective film (C2) having an adhesive layer was obtained in the same manner as in Example 1. . In addition, the obtained surface protection film (C2) can be used also as an adhesive sheet.
The evaluation results are shown in Table 1.

Example 7
The surface protective film (1) obtained in Example 1 was attached to a polarizing plate (manufactured by Nitto Denko Corporation, trade name “TEG1465DUHC”) which is an optical member, and the optical member to which the surface protective film was attached was attached. Obtained.

Example 8
The surface protective film (1) obtained in Example 1 was attached to a conductive film (Nitto Denko Corporation, trade name “Electrista V270L-TFMP”) which is an electronic member, and the surface protective film was attached. An electronic member was obtained.

  The pressure-sensitive adhesive sheet and surface protective film of the present invention can be used for applications such as sticking to the surface of an optical member or electronic member to protect the surface.

DESCRIPTION OF SYMBOLS 1 Base material layer 2 Adhesive layer 10 Adhesive sheet or surface protection film

Claims (10)

A pressure-sensitive adhesive containing a polyurethane resin,
The polyurethane resin is a polyurethane resin obtained by curing a composition containing a polyol (A) having two or more OH groups and a polyfunctional isocyanate compound (B) using a catalyst (C),
The catalyst (C) is 0.01 to 5 parts by weight with respect to 100 parts by weight of the polyol (A),
The polyol (A) is two or more kinds of polyether polyols,
The two or more kinds of polyols are polyols having at least one kind having two OH groups, and at least one kind being a polyol having three or more OH groups,
The number average molecular weight Mn of the polyol having 2 OH groups is 6000 or more, the number average molecular weight Mn of the polyol having 3 or more OH groups is 2000 or more,
In the polyol (A) and the polyfunctional isocyanate compound (B), the equivalent ratio of the NCO group to the OH group is 0.1 to 5.0 as the NCO group / OH group,
When the initial adhesive force immediately after sticking to the acrylic plate is A, and the adhesive strength after 70 ° C. × 1 day after sticking to the acrylic plate is B,
The initial adhesive strength A is 0.001 N / 20 mm to 2.0 N / 20 mm,
The adhesive strength B after 1 day at 70 ° C. is 0.1 N / 20 mm or more,
The adhesive strength B after 1 day at 70 ° C. is 2.0 times or more of the initial adhesive strength A.
Adhesive. A pressure-sensitive adhesive containing a polyurethane resin,
The polyurethane resin is a polyurethane resin obtained by curing a composition containing a polyol (A) having two or more OH groups and a polyfunctional isocyanate compound (B) using a catalyst (C),
The catalyst (C) is 0.01 to 5 parts by weight with respect to 100 parts by weight of the polyol (A),
The polyol (A) is two or more kinds of polyether polyols,
The two or more kinds of polyols are polyols having at least one kind having two OH groups, and at least one kind being a polyol having three or more OH groups,
The number average molecular weight Mn of the polyol having 2 OH groups is less than 6000, the number average molecular weight Mn of the polyol having 3 or more OH groups is less than 2000,
In the polyol (A) and the polyfunctional isocyanate compound (B), the equivalent ratio of NCO groups to OH groups is less than 1.3 as NCO groups / OH groups,
When the initial adhesive force immediately after sticking to the acrylic plate is A, and the adhesive strength after 70 ° C. × 1 day after sticking to the acrylic plate is B,
The initial adhesive strength A is 0.001 N / 20 mm to 2.0 N / 20 mm,
The adhesive strength B after 1 day at 70 ° C. is 0.1 N / 20 mm or more,
The adhesive strength B after 1 day at 70 ° C. is 2.0 times or more of the initial adhesive strength A.
Adhesive. The pressure-sensitive adhesive according to claim 1 or 2 , wherein the polyol (A) contains 50% by weight or more of a polyol having two OH groups. The adhesive sheet which has an adhesive layer which consists of an adhesive in any one of Claim 1 to 3 in the at least single side | surface of a base material layer. An optical member to which the pressure-sensitive adhesive sheet according to claim 4 is adhered. An electronic member to which the pressure-sensitive adhesive sheet according to claim 4 is adhered. The surface protection film which has an adhesive layer which consists of an adhesive in any one of Claim 1 to 3 in the single side | surface of a base material layer. The surface protection film of Claim 7 used for the surface protection of an optical member or an electronic member. An optical member to which the surface protective film according to claim 8 is attached. The electronic member with which the surface protection film of Claim 8 was stuck.