JP2019056052A - Protective sheet, and laminate with protective sheet - Google Patents

Abstract

SOLUTION: The present disclosure provides a protective sheet including an adhesive layer, and a base material disposed on one side face of the adhesive layer where the adhesive layer has the characteristics of reducing an adhesive strength from an initial adhesive strength by irradiating with energy ray, and the adhesive layer contains an antistatic agent.SELECTED DRAWING: Figure 1

Description

  The present disclosure relates to a protective sheet and a laminate with a protective sheet.

  For example, in the manufacturing process of a flexible printed circuit board (FPC), a printed circuit board (PCB), etc., the substrate is damaged, contaminated by a chemical, used in the manufacturing process or during the manufacturing process. Deterioration of the substrate may occur due to heating. Therefore, in the manufacturing process of the substrate, a technique using a protective sheet for protecting the surface of the substrate has been proposed for the purpose of preventing the scratches, contamination, deterioration, and the like as described above (for example, Patent Documents). 1-3). A protective sheet has a base material and the adhesion layer arrange | positioned at one surface of the said base material, for example.

  Such a protective sheet is a member that is finally peeled off from a product that is a protected member. Therefore, as a pressure-sensitive adhesive layer in a protective sheet, a technique using a material having a weak adhesive force has been conventionally known.

Japanese Patent No. 5361760 Patent No. 5875318 JP 2017-8173 A

  The protective sheet affixed to the member to be protected is a member that is finally peeled off from the member to be protected. Therefore, it is preferable to use an adhesive layer having a property capable of peeling the protective sheet from the member to be protected. As such an adhesive layer, conventionally, an adhesive layer having a slightly adhesive force is used. The pressure-sensitive adhesive layer having a slight adhesive strength has the advantage of having a predetermined peelability, while the initial adhesive strength is slightly adhesive, so that the adhesive layer cannot be sufficiently adhered to the protected member. There is a problem in the function of protecting the member. On the other hand, there is an adhesive layer that can reduce the adhesive strength by irradiation of energy rays and improve the peelability. The pressure-sensitive adhesive layer that lowers the adhesive strength by irradiation with energy rays can increase the initial adhesive strength before irradiating energy rays, and can reduce the adhesive strength after irradiation with energy rays from the initial adhesive strength. Therefore, the protective sheet using the pressure-sensitive adhesive layer can improve adhesion to the member to be protected and can be easily peeled off from the member to be protected.

  The inventors of the present disclosure have repeatedly investigated a protective sheet using an adhesive layer capable of reducing the adhesive strength by irradiation of energy rays, and the protective sheet has excellent peelability. I discovered the following new issues. That is, in the case of an adhesive layer having the property that the adhesive strength is reduced from the initial adhesive strength by irradiation of energy rays, the peeling speed when peeling the protective sheet from the protected member tends to increase by having excellent peelability. is there. In the present disclosure, static electricity is generated between the protected member and the protective sheet when the protective sheet is peeled from the protected member as the peeling speed when peeling the protective sheet from the protected member is increased. I found a new problem that would be easier.

  This indication is made in view of the above-mentioned situation, and is a protection sheet which has an adhesion layer which can reduce adhesive power by irradiation of energy rays, and when peeling a protection sheet from a member to be protected The main object of the present invention is to provide a protective sheet capable of suppressing the generation of static electricity between the member to be protected and the protective sheet.

  In the present disclosure, the pressure-sensitive adhesive layer and a base material disposed on one surface of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer has a characteristic that the pressure-sensitive adhesive force is reduced from the initial pressure-sensitive adhesive force by irradiation with energy rays. The adhesive layer provides a protective sheet containing an antistatic agent.

  Further, in the present disclosure, a protective sheet-attached laminate in which a protective sheet and a member to be protected are laminated, the protective sheet being a base disposed on one surface of the adhesive layer and the adhesive layer. The pressure-sensitive adhesive layer has a property that the pressure-sensitive adhesive force is reduced from the initial pressure-sensitive adhesive force by irradiation of energy rays, and the pressure-sensitive adhesive layer provides a laminate with a protective sheet containing an antistatic agent.

  The protective sheet of the present disclosure has an adhesive layer capable of reducing the adhesive strength by irradiation of energy rays, and suppresses generation of static electricity with the protected member when peeling from the protected member. There is an effect that can be.

It is a schematic sectional drawing which shows an example of the protection sheet of this indication. It is a schematic sectional drawing which shows an example of the laminated body with a protection sheet of this indication.

  In this specification, when a certain configuration such as a certain member or a certain region is “above (or below)” another configuration such as another member or another region, unless otherwise limited, This includes not only when directly above (or directly below) another configuration, but also when above (or below) another configuration, i.e., another configuration above (or below) another configuration. This includes cases where elements are included.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure can be implemented in many different modes, and should not be construed as being limited to the description of the embodiments described below. Further, in order to clarify the description, the drawings may be schematically represented with respect to the width, thickness, shape, etc. of each part as compared with the embodiment, but are merely examples, and the interpretation of the present disclosure may be interpreted. It is not limited. In addition, in the present specification and each drawing, elements similar to those described above with reference to the previous drawings are denoted by the same reference numerals, and detailed description may be omitted as appropriate. Further, for convenience of explanation, the description may be made using the terms “upper” or “lower”, but the vertical direction may be reversed.

Hereinafter, the protective sheet and the laminate with a protective sheet of the present disclosure will be described in detail.
In the present disclosure, “sheet” and “film” may be used synonymously.

A. Protective sheet The protective sheet of the present disclosure has an adhesive layer and a base material disposed on one surface of the adhesive layer, and the adhesive layer has an adhesive force that decreases from the initial adhesive force by irradiation with energy rays. The pressure-sensitive adhesive layer is a member containing an antistatic agent.

  The protective sheet of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of the protective sheet of the present disclosure, and FIG. 2 is a schematic cross-sectional view showing an example of a laminate with a protective sheet in which the protective sheet of the present disclosure is laminated on a member to be protected. As shown in FIG. 1, the protective sheet 10 of the present disclosure includes an adhesive layer 1 and a base material 2 disposed on one surface of the adhesive layer 1. Moreover, the adhesive layer 1 in this indication has the characteristic that adhesive force falls from initial adhesive force by irradiation of an energy ray, and the adhesive layer 1 contains an antistatic agent. Such a protective sheet of the present disclosure is a member that is attached to the surface of the protected member 20 and protects the surface of the protected member 20 as shown in FIG.

  According to the present disclosure, it has an adhesive layer capable of reducing the adhesive force by irradiation of energy rays, and suppresses generation of static electricity with the protected member when peeling from the protected member. There is an effect that can be.

1. Adhesive layer The adhesive layer in this indication is a member arranged at one side of a substrate. The adhesive layer is a member that is in close contact with the surface of the member to be protected. Here, “adhesion” is a concept included in “adhesion”. Adhesion is used to mean a temporary adhesion phenomenon, whereas adhesion is sometimes used to mean a permanent adhesion phenomenon (Iwanami Shoten RIKEN Encyclopedia 5th edition). “Adhesiveness” and “adhesive strength” refer to the property of adhesion by pressure sensitivity and the adhesive strength at that time.

  Hereinafter, the characteristics and composition of the adhesive layer will be described.

(1) Characteristics The adhesive layer in the present disclosure is a layer for attaching a protective sheet to a member to be protected. The pressure-sensitive adhesive layer in the present disclosure contains an antistatic agent, and thereby can exhibit an antistatic function. Here, the antistatic function is a function of suppressing the generation of static electricity when the protective sheet is peeled from the member to be protected. When the protective sheet is peeled from the protected member, if static electricity is generated between the protective sheet and the protected member, impurities such as dust may adhere to the surface of the protected member. Further, when the protected member is a TFT element of a liquid crystal cell, the TFT element or the like may be destroyed by static electricity.

The antistatic function of the pressure-sensitive adhesive layer as referred to in the present disclosure can be evaluated, for example, by measuring the surface specific resistance value. The surface specific resistance value of the adhesive layer is, for example, preferably 1.0 × 10 ¹¹ Ω / □ or less, and more preferably 1.0 × 10 ⁹ Ω / □ or less. When the surface specific resistance value of the adhesive layer is within the above range, when the protective sheet affixed to the protected member is peeled off, even if the peeling speed is increased, it is between the protected member and the protective sheet. It is possible to suppress the generation of static electricity. In addition, the surface specific resistance value of the adhesive layer is determined, for example, by applying a digital insulation meter (for example, Loresta-GP MCP- manufactured by Mitsubishi Chemical Corporation) in accordance with JIS K7194. T610).

  The pressure-sensitive adhesive layer in the present disclosure has a characteristic that the pressure-sensitive adhesive force decreases from the initial pressure-sensitive adhesive force by irradiation with energy rays. In other words, the pressure-sensitive adhesive layer has re-peelability that peels off from the member to be protected by irradiation with energy rays. Here, that the adhesive layer exhibits removability means that the protective sheet can be adhered and adhered to the member to be protected by the adhesive layer and fixed, and when the protective sheet is peeled from the member to be protected, It means that the protective member can be peeled off without destroying the protective member and suppressing generation of adhesive residue on the surface of the protected member.

  The pressure-sensitive adhesive layer in the present disclosure can be sufficiently adhered and fixed to the surface of the member to be protected by the initial pressure-sensitive adhesive force. Also, when peeling the protective sheet from the protected member, the adhesive layer is irradiated with energy rays to reduce the adhesive strength of the adhesive layer and improve the peelability. Generation | occurrence | production of this can be suppressed and a protection sheet can be peeled easily.

  Here, the pressure-sensitive adhesive layer in the present disclosure is peeled off from the member to be protected by energy ray irradiation. The pressure-sensitive adhesive layer in the present disclosure exhibits strong adhesion and is closely fixed to the member to be protected before receiving the energy ray irradiation. However, when irradiated with energy rays, it means that the adhesive strength is remarkably lowered and can be easily peeled off from the protected member. Specifically, the adhesive layer in the present disclosure has an adhesive force before irradiation with energy rays of 0.5 N / 25 mm or more and 20 N / 25 mm or less, and an adhesive force after irradiation with energy rays of 2.0 N / 25 mm or less. Is preferred. For the adhesive strength of the adhesive layer, a polyester film (thickness 50 μm) is used as a base material, and an adhesive base material formed on one side of the base material so that the adhesive layer in the present disclosure is within the thickness range described below is used. A strip-shaped test piece having a width of 25 mm and a length of 150 mm was cut and then laminated on a stainless steel plate under the conditions conforming to the standard of JIS Z0237. Finally, the test piece was peeled at an angle of 180 ° and peeled off. It can be measured by peeling in the length direction of the test piece under conditions of 300 mm / min and room temperature. Further, for such 180 ° peel strength measurement, for example, a universal testing machine 5565 manufactured by Instron can be used.

  Examples of energy rays applied to the adhesive layer include rays of far ultraviolet rays, ultraviolet rays, near ultraviolet rays, infrared rays and the like, electromagnetic waves such as X rays and γ rays, electron beams, proton rays, and neutron rays. Of these, ultraviolet rays are preferred from the viewpoint of versatility.

  The pressure-sensitive adhesive layer in the present disclosure preferably has a predetermined light transmittance with respect to the energy rays used. Specifically, the light transmittance of the adhesive layer with respect to the energy rays used is preferably 10% or more, for example, when the thickness is 50 μm, more preferably 20% or more, and particularly preferably 30% or more. Preferably there is. When the light transmittance of the pressure-sensitive adhesive layer is within the above range, sufficient energy is applied to the pressure-sensitive adhesive layer when the pressure-sensitive adhesive layer of the protective sheet is weakened by irradiating it with energy rays after the protective sheet is applied to the member to be protected. It becomes possible to irradiate a line. Moreover, light permeability can be improved also as a protective sheet because an adhesion layer has favorable light transmittance. Therefore, it is possible to suppress the occurrence of a problem that light is blocked by the protective sheet when light is irradiated to the protected member to which the protective sheet is attached in the manufacturing process. The light transmittance of the pressure-sensitive adhesive layer can be measured using a generally known method according to the type of energy beam used.

  Further, when the energy ray irradiated to the adhesive layer is ultraviolet, the ultraviolet transmittance when the thickness of the adhesive layer is 50 μm is preferably 10% or more, and more preferably 20% or more. It is preferable that it is 30% or more. In addition, the ultraviolet-ray transmittance of an adhesion layer can be measured using JASCO Corporation V-7100, for example.

(2) Composition The composition of the adhesive layer in the present disclosure only needs to contain an antistatic agent and exhibit a predetermined adhesive strength before and after irradiation with energy rays. As such an adhesion layer, it can be set as the composition which contains resin (adhesive main ingredient), an energy-beam polymerizable oligomer, and a polymerization initiator at least other than an antistatic agent, for example. By having the antistatic agent, it is possible to suppress the generation of static electricity with the member to be protected when peeling from the member to be protected.

  Hereinafter, each composition contained in the pressure-sensitive adhesive composition constituting the pressure-sensitive adhesive layer will be described.

(A) Antistatic agent In the present disclosure, the “antistatic agent” is contained in an adhesive layer to suppress generation of static electricity with a protected member when peeling from the protected member. Any material can be used as long as the effect that it can be obtained is obtained, and there is no particular limitation. That is, the antistatic agent in the present disclosure is preferably a material having an antistatic function.

  Examples of such an antistatic agent include an ion conduction type antistatic agent and an electron conduction type antistatic agent. Examples of the ion conductive antistatic agent include various cationic antistatic agents having first to third amino groups such as quaternary ammonium salts and pyridium salts, sulfonate groups, sulfate ester bases, and phosphate esters. Anionic antistatic agents having anionic groups such as bases and phosphonic acid bases, amphoteric antistatic agents such as amino acids and amino acid sulfate esters, nonionic antistatic agents such as amino alcohols, glycerols and polyethylene glycols Is mentioned. Examples of the electron conduction type antistatic agent include conductive polymers such as polyacetylene-based and polythiophene-based conductive particles, metal fine particles, and metal oxide fine particles. In the present disclosure, for example, an antistatic agent in which a conductive polymer such as polyacetylene or polythiophene is combined with a dopant, or an antistatic agent in which conductive fine particles are contained in a conductive polymer may be used.

  Examples of the antistatic agent made of a conductive polymer include polyacetylene, polyaniline, polythiophene, polypyrrole, polyphenylene sulfide, poly (1,6-heptadiyne), polybiphenylene (polyparaphenylene), polyparafinylene sulfide, polyphenylacetylene, Examples thereof include conductive polymers such as poly (2,5-thienylene) or derivatives thereof. Specific examples of the conductive polymer include polythiophene-based conductive organic polymers (for example, 3,4-ethylenedioxythiophene (PEDOT)). By using an antistatic agent composed of a conductive organic polymer, an adhesive layer having high light transmittance and a low haze value can be obtained.

Examples of the metal constituting the metal fine particles include Au, Ag, Cu, Al, Fe, Ni, Pd, and Pt alone or an alloy of these metals. Examples of the metal oxide constituting the metal oxide fine particles include tin oxide (SnO ₂ ), antimony oxide (Sb ₂ O ₅ ), antimony tin oxide (ATO), indium tin oxide (ITO), and aluminum. Examples thereof include zinc oxide (AZO), fluorinated tin oxide (FTO), ZnO, and the like.

  The conductive fine particles can have an average primary particle diameter of, for example, 5 nm or more and 5 μm or less, and particularly 50 nm or more and 1 μm or less. In the present disclosure, when the average primary particle diameter of the conductive fine particles is in the above range, the adhesive layer can be provided with a good antistatic function, and when the adhesive layer is irradiated with energy rays, the adhesive layer Thus, it is possible to maintain the light transmittance to the extent that the energy beam is sufficiently irradiated. The average primary particle diameter of the conductive fine particles can be measured using, for example, a MICROTRAC particle size analyzer manufactured by Kikkiso Co., Ltd. In the adhesive layer, a transmission electron microscope (TEM) photograph of a cross section of the adhesive layer or scanning transmission is used. It can be set as the average value of the particle diameter of 10 conductive fine particles observed by an electron microscope (STEM) photograph. Further, the conductive fine particles may be chain-like or needle-like.

  The content of the antistatic agent in the pressure-sensitive adhesive layer is preferably an amount that can impart a desired antistatic function to the pressure-sensitive adhesive layer, and can be appropriately adjusted according to the type of the antistatic agent. The specific content of the antistatic agent is, for example, preferably 1 part by mass or more, particularly 3 parts by mass with respect to 100 parts by mass of the resin component of the total solid content of the adhesive composition constituting the adhesive layer. It is preferable that it is above, and it is particularly preferable that it is 5 parts by mass or more. Further, the content of the antistatic agent is preferably 50 parts by mass or less, more preferably 35 parts by mass or less, and particularly preferably 25 parts by mass or less. When the content of the antistatic agent is within the above range, a desired antistatic function can be imparted to the adhesive layer, and generation of static electricity with the protected member when peeling from the protected member. Can be effectively suppressed.

(B) Resin (adhesive agent)
As resin used for an adhesive composition, acrylic resin is mentioned, for example. The acrylic resin is not particularly limited. For example, a (meth) acrylic acid ester polymer obtained by homopolymerizing a (meth) acrylic acid ester, a (meth) acrylic acid ester as a main component and a (meth) acrylic acid ester (Meth) acrylic acid ester copolymers obtained by copolymerization with the above monomers are preferred, and (meth) acrylic acid ester copolymers are preferred. Specific examples of (meth) acrylic acid esters and other monomers include those disclosed in, for example, JP-A-2012-31316. Other monomers can be used alone or in combination of two or more. In addition, the main component here means that a copolymerization ratio is 51 mass% or more, Preferably it is 65 mass% or more.

  Above all, as the acrylic resin, a (meth) acrylic ester copolymer obtained by copolymerization with a (meth) acrylic acid ester as a main component and a hydroxyl group-containing monomer copolymerizable with the (meth) acrylic acid ester. Or a (meth) acrylic acid ester copolymer obtained by copolymerization with a (meth) acrylic acid ester as a main component and a hydroxyl group-containing monomer and a carboxyl group-containing monomer copolymerizable with the above (meth) acrylic acid ester. It can be used suitably.

  The copolymerizable hydroxyl group-containing monomer and carboxyl group-containing monomer are not particularly limited, and for example, a hydroxyl group-containing monomer and a carboxyl group-containing monomer disclosed in JP 2012-31316 A are used.

  The mass average molecular weight (Mw) of the acrylic resin is preferably in the range of 200,000 to 1,000,000, and more preferably in the range of 200,000 to 800,000. It is because sufficient initial adhesive force can be exhibited by setting the mass average molecular weight of the acrylic resin within the above range.

  When the acrylic resin is a (meth) acrylic acid ester copolymer of a hydroxyl group-containing monomer and a carboxyl group-containing monomer copolymerizable with a (meth) acrylic acid ester, the hydroxyl group-containing monomer and the carboxyl group As a mass ratio with a containing monomer, it is preferable to exist in the range of 51: 49-100: 0, and it is preferable that it is especially 75: 25-100: 0. If the weight ratio of each monomer is within the above range, it can be expected that the adhesive force will be effectively reduced by irradiation with energy rays, and it prevents the adhesive residue from being generated on the protected member side when the protective sheet of the present disclosure is peeled off. Because it can.

(c) Energy ray-polymerizable oligomer The energy-ray-polymerizable oligomer is not particularly limited as long as it is polymerized upon irradiation with energy rays. For example, photoradical polymerizability, photocationic polymerizability, photoanion polymerizability, etc. The oligomer of these is mentioned. Among these, a photo-radically polymerizable oligomer is preferable. This is because the curing speed is high, and a variety of compounds can be selected. Furthermore, physical properties such as adhesiveness before curing and peelability after curing can be easily controlled. Examples of the photoradical polymerizable oligomer include those disclosed in JP 2012-31316 A, and these may be used alone or in combination of two or more.

  The mass average molecular weight (Mw) of the energy beam polymerizable oligomer is not particularly limited, but is preferably in the range of 250 to 8000, and more preferably in the range of 250 to 5000, for example. When the mass average molecular weight is within the above range, the adhesive layer exhibits desired adhesiveness before energy beam irradiation, and after energy beam irradiation, the generation of adhesive residue on the protected member side is suppressed and easily peeled off. This is because it becomes possible.

  The pressure-sensitive adhesive composition can control the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer after irradiation with energy rays by adjusting the amount of the energy ray-polymerizable oligomer. The content of the energy beam polymerizable oligomer in the pressure-sensitive adhesive composition is preferably 10 to 60 parts by weight, more preferably 20 to 50 parts by weight, with respect to 100 parts by weight of the acrylic resin. It is preferable. If the content is within the above range, the crosslink density of the pressure-sensitive adhesive layer after energy beam irradiation is sufficient, so that desired peelability can be realized. Moreover, generation | occurrence | production of the adhesive residue to the to-be-protected member side by the fall of the cohesion force of an adhesive composition can be suppressed.

(D) Polymerization initiator As the polymerization initiator, a general photopolymerization initiator can be used. Among them, the temperature is increased from 30 ° C. to 190 ° C. at a temperature increase rate of 10 ° C./min. A photopolymerization initiator having a weight reduction rate of 50% or less, particularly 20% or less by thermogravimetry when maintained for 30 minutes is preferred. In addition, the said weight decreasing rate can be calculated | required by measuring a weight using commercially available thermogravimetry apparatus, for example, DTG-60A by Shimadzu Corporation. Specifically, the polymerization initiator is analyzed (atmosphere gas: nitrogen, gas flow rate: 50 ml / min, temperature range: 30 ° C. to 190 ° C., temperature rising condition: 10 ° C./min), and the polymerization starts at 30 ° C. The weight (W1) of the agent and the weight (W2) of the polymerization initiator 30 minutes after reaching 190 ° C. can be measured and calculated from the following formula.
Weight reduction rate (%) = [(W1 (g) −W2 (g)) / W1 (g)] × 100

  As a commercial item of such a polymerization initiator, IRGACURE754 (made by BASF Japan), IRGACURE2959 (made by BASF Japan), etc. are mentioned, for example.

  The content of the polymerization initiator in the pressure-sensitive adhesive composition is 0.01 parts by weight or more and 10 parts by weight or less, and more preferably 0.5 parts by weight or more with respect to 100 parts by weight in total of the acrylic resin and the energy beam polymerizable oligomer. The amount is preferably 3 parts by weight or less. If the content of the polymerization initiator is less than the above range, the polymerization reaction of the energy beam polymerizable oligomer does not sufficiently occur, the adhesive force of the adhesive layer after energy beam irradiation becomes excessively high, and the peelability can be realized. On the other hand, if the above range is exceeded, the energy rays may reach only in the vicinity of the energy ray irradiation surface, and the adhesive layer may be insufficiently cured. In addition, the cohesive strength of the pressure-sensitive adhesive composition may be reduced, which may cause adhesive residue. When the pressure-sensitive adhesive composition contains an energy beam polymerizable oligomer and an energy beam polymerizable monomer described later, a total of 100 parts by weight of the acrylic resin, the energy beam polymerizable oligomer, and the energy beam polymerizable monomer On the other hand, the content of the polymerization initiator is preferably within the above range.

(E) Crosslinking agent The crosslinking agent is not particularly limited as long as it crosslinks at least between acrylic resins, and examples thereof include an isocyanate crosslinking agent and an epoxy crosslinking agent. Specific examples of the isocyanate-based crosslinking agent and the epoxy-based crosslinking agent include those disclosed in Japanese Patent Application Laid-Open No. 2012-31316. A crosslinking agent can be used individually or in combination of 2 or more types, and can be suitably selected according to the kind etc. of acrylic resin.

As content of the crosslinking agent in an adhesive composition, it can set suitably according to the kind of crosslinking agent, For example, 0.01 weight part or more and 15 weight part or less with respect to 100 weight part of acrylic resins, In particular, the amount is preferably 0.01 parts by weight or more and 10 parts by weight or less.
If the content of the cross-linking agent is less than the above range, when the adhesion between the adhesive layer and the member to be protected is inferior, or when the protective sheet is peeled from the member to be protected, the adhesive layer causes cohesive failure and is protected. Adhesive residue may occur on the member side. On the other hand, if the content of the cross-linking agent exceeds the above range, the cross-linking agent remains as an unreacted monomer in the adhesive layer after irradiation with energy rays, which causes generation of adhesive residue due to a decrease in cohesive force. There is.

(F) Arbitrary composition The pressure-sensitive adhesive composition may contain an energy beam polymerizable monomer in addition to the energy beam polymerizable oligomer described above. When the energy ray is irradiated, the pressure-sensitive adhesive composition is cured by three-dimensional crosslinking to reduce the pressure-sensitive adhesive force, and the cohesive force of the pressure-sensitive adhesive composition is increased so as not to transfer to the protected member side. Because it can. As the energy ray polymerizable monomer, a radical photopolymerizable monomer is preferable, and among them, a polyfunctional acrylate or a polyfunctional methacrylate having three or more (meth) acryloyl groups in one molecule is preferable. Specific examples include energy beam polymerizable monomers described in JP2010-173091A.

  When the energy ray polymerizable oligomer and the energy ray polymerizable monomer are contained in the pressure-sensitive adhesive composition, the total content thereof is 10 parts by weight with respect to 100 parts by weight of the acrylic resin. It is more preferably 60 parts by weight or less, and particularly preferably 20 parts by weight or more and 50 parts by weight or less. Crosslink density after irradiation with energy rays is sufficient, and proper releasability can be achieved, and the generation of adhesive residue on the protected member side due to the decrease in cohesive force of the pressure-sensitive adhesive composition can be suppressed. Because it can.

  The pressure-sensitive adhesive composition can be a silane coupling agent, a tackifier, a metal chelating agent, a surfactant, an antioxidant, an ultraviolet absorber, a pigment, a dye, a colorant, an antiseptic, an antifoaming agent, if necessary. Various additives such as a wettability adjusting agent may be included.

(3) Others The thickness of the pressure-sensitive adhesive layer in the present disclosure may be any size as long as sufficient adhesive strength can be obtained and energy rays can penetrate to the inside. Therefore, the thickness of the adhesive layer can be appropriately adjusted according to the type and content of the antistatic agent contained in the adhesive layer. As a specific thickness of the adhesive layer, for example, it is preferably 3 μm or more and 50 μm or less, and more preferably 5 μm or more and 30 μm or less.

  The pressure-sensitive adhesive composition in the present disclosure can be prepared by mixing the above-described components and kneading or dispersing as necessary. The kneading or dispersing method is not particularly limited, and for example, a conventionally known kneading and dispersing machine disclosed in JP-A-2014-234460 can be applied. The pressure-sensitive adhesive composition may be mixed with each component by adding a diluting solvent for viscosity adjustment.

2. Base material The protective sheet of this indication has a base material in one side of an adhesion layer. The substrate is preferably a layer that can support the adhesive layer. The base material in the present disclosure is a member that can impart heat resistance, chemical resistance, and the like to the protective sheet. Therefore, for example, in the manufacturing process of the protected member, in order to prevent the surface of the protected member from being deteriorated or contaminated by heating or chemicals in the manufacturing process, a protective sheet having a substrate on the surface of the protected member is provided. When affixed, the protected member can be well protected from heat and chemicals.

  The substrate in the present disclosure preferably has a predetermined heat resistance. It is because a heat resistant function can be imparted to the protective sheet of the present disclosure. The heat resistance of the base material is, for example, that the thermal expansion coefficient of the base material within the range of 150 ° C. to 250 ° C. is within the range of 5 ppm / ° C. to 50 ppm / ° C., in particular within the range of 10 ppm / ° C. to 30 ppm / ° C. Is preferred.

  The base material may or may not have flexibility. Examples of such a substrate include inorganic substrates such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plate, and resin substrates such as a resin film and an optical resin plate.

  As the resin used for the resin base material, those exhibiting the above-mentioned thermal expansion coefficient are preferable. In particular, in addition to the above physical properties, dimensional stability, energy ray permeability, rigidity, extensibility, stackability, chemical resistance In addition, polyimide resins, polyphenylene sulfide resins, polyester resins, and glass epoxy resins (glass epoxy) are preferable. The resin base material may be a single layer composed of one kind of resin, or may be a multilayer body in which two or more kinds of resin base materials are laminated.

  The thickness of the substrate is not particularly limited, and can be appropriately selected depending on the material, the presence / absence of flexibility, and the type of the adhesive layer.

  The form of the substrate is not particularly limited, and examples thereof include a plate shape, a sheet shape, a film shape, and a tape shape according to the presence or absence of flexibility. Further, the substrate may be in a roll shape or a single wafer shape.

  The substrate preferably has transparency. Sufficient energy rays can be applied from the substrate side to reduce the adhesive strength of the adhesive layer. The light transmittance of the base material at this time may be set as appropriate as long as a desired amount of energy rays can be transmitted.

  The base material may be subjected to surface treatment such as corona treatment or primer treatment on the surface on which the adhesive layer is formed in order to enhance the adhesion with the adhesive layer.

3. Other Configurations The protective sheet of the present disclosure only needs to have the above-described adhesive layer and base material, but may have other configurations as necessary. Examples of other configurations include a separator. Hereinafter, the separator will be described.

  The protective sheet of the present disclosure may have a separator on the surface of the pressure-sensitive adhesive layer opposite to the base material. The separator is provided so as to be peelable from the pressure-sensitive adhesive layer, and is peeled from the pressure-sensitive adhesive layer when the protective sheet is attached to the member to be protected. By providing a separator on the surface of the pressure-sensitive adhesive layer, the surface of the pressure-sensitive adhesive layer becomes dirty or damaged until the protective sheet is attached to the member to be protected via the pressure-sensitive adhesive layer, and the initial pressure-sensitive adhesive force of the pressure-sensitive adhesive layer is reduced. Can be suppressed.

  As such a separator, conventionally well-known separators, such as a release film, a separate paper, a separate film, a separate paper, a peeling film, a peeling paper, can be used, for example. Specific examples include polypropylene, polyethylene, and fluorine film. In addition, the separator may have a releasability with a single layer exemplified above, but a release layer on one or both sides of a release paper substrate such as fine paper, coated paper, impregnated paper, and plastic film. You may use the laminated body which formed. The release layer is not particularly limited as long as it has a release property. For example, silicone resin, organic resin-modified silicone resin, fluororesin, aminoalkyd resin, melamine resin, acrylic resin, polyester resin, long chain There are alkyl resins. These resins can be used in any of emulsion type, solvent type and solventless type.

  The separator is preferably subjected to an easy peeling treatment on the surface in contact with the adhesive layer.

The separator may have moisture resistance. This is because when the separator has moisture resistance, contact between the adhesive layer and moisture can be prevented until the protective sheet is attached to the member to be protected via the adhesive layer. The separator having moisture resistance means that, for example, the water vapor permeability of the separator under a temperature of 40 ° C. and a humidity of 90% RH is preferably 1 g / m ² / day or less, more preferably 0.1 g / m ² / day or less. It is preferable. The water vapor transmission rate can be measured according to JIS K7129. Examples of the moisture-proof separator include an aluminum vapor-deposited film, a silica vapor-deposited film, an aluminum foil, a polyethylene film having a thickness of 0.1 mm or more, and a film containing a moisture-proof filler.

  The separator may have light shielding properties depending on the type of material contained in the adhesive layer and the construction environment. This is because it is possible to prevent the adhesive layer from being deteriorated by being irradiated with ultraviolet rays or the like until the protective sheet is attached to the member to be protected via the adhesive layer. Examples of the light-shielding separator include an aluminum foil separator, an aluminum vapor-deposited film or paper separator, a colored separator, a film separator containing an ultraviolet absorber, and the like.

B. Laminated body with protective sheet The laminated body with protective sheet of the present disclosure is a laminated body in which a protective sheet and a member to be protected are laminated, and the protective sheet includes an adhesive layer and one surface of the adhesive layer. The adhesive layer has a property that the adhesive strength is reduced from the initial adhesive strength by irradiation of energy rays, and the adhesive layer is a laminate containing an antistatic agent. .

  The description of the laminate with a protective sheet of the present disclosure using the drawings can be the same as the description of FIG. 2 described in the above section “A. Protective Sheet”, and thus the description thereof is omitted here. .

  According to the present disclosure, the protective sheet having the protective sheet described above can suppress the generation of static electricity between the protected member and the protective sheet when the protective sheet is peeled from the protected member. It can be set as a laminated body. In addition, since description of the detailed effect in this indication can be made to be the same as that of the content demonstrated by the term of the "A. protective sheet" mentioned above, description here is abbreviate | omitted.

1. Protective sheet The protective sheet in this indication has an adhesion layer and a substrate arranged on one side of the above-mentioned adhesion layer, and the above-mentioned adhesion layer reduces adhesive strength from initial adhesive strength by irradiation of energy rays. The pressure-sensitive adhesive layer is a member containing an antistatic agent.

  About the protective sheet in this indication, since it can be made to be the same as that of the contents explained by the above-mentioned "A. protective sheet" section, description here is omitted.

2. Protected member The protected member in this indication is a member which can laminate the protective sheet mentioned above, and is not specifically limited. Specific examples of protected members include FPC, PCB, SIP (System in a Package), SOP (Small Outline Package), PLP (Panel Level Package), WLP (Wafer Level Package), and CSP (Chip Size Package). And package parts such as POP (Package on Package), sensor modules, and liquid crystal modules such as touch panels and organic EL panels.

  In addition, this indication is not limited to the said embodiment. The above-described embodiment is an exemplification, and the present invention has the same configuration as the technical idea described in the claims of the present disclosure and has the same function and effect regardless of the present embodiment. It is included in the technical scope of the disclosure.

DESCRIPTION OF SYMBOLS 1 ... Adhesive layer 2 ... Base material 10 ... Protection sheet 20 ... Protected member 100 ... Laminated body with a protection sheet

Claims (2)

An adhesive layer;
A substrate disposed on one side of the adhesive layer,
The adhesive layer has the property that the adhesive strength decreases from the initial adhesive strength by irradiation of energy rays,
The adhesive layer is a protective sheet containing an antistatic agent. A protective sheet and a laminate with a protective sheet in which a member to be protected is laminated,
The protective sheet has an adhesive layer and a substrate disposed on one surface of the adhesive layer,
The adhesive layer has the property that the adhesive strength decreases from the initial adhesive strength by irradiation of energy rays,
The adhesive layer is a laminate with a protective sheet containing an antistatic agent.

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