JP2019038922A - Protective sheet and laminate with protective sheet - Google Patents

Abstract

The present disclosure includes an adhesive layer and a base material disposed on one surface of the adhesive layer, and the adhesive layer has a characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays. The adhesive layer provides a protective sheet containing a fluororesin. [Selection] 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 example, Patent Document 1) for the purpose of preventing damage, contamination, deterioration, and the like as described above. ~ 3). Such a protective sheet has a base material and the adhesion layer arrange | positioned on the one surface of the said base material, for example. Moreover, a protective sheet is a member finally peeled from the product which is a to-be-protected member.

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. While the adhesive layer having a slight adhesive strength has an advantage of having a predetermined peeling force, the initial adhesive strength is slightly adhesive, so that the adhesive layer cannot be sufficiently adhered to the member to be protected. 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 force by irradiation of energy rays and improve the peeling force. 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.

  In recent years, various products have been used as the member to be protected. For example, when the surface of the member to be protected where the protective sheet is attached is a wide area, the following new problems have been discovered. That is, when peeling the protective sheet affixed to the protected member, the force required to peel the protective sheet from the protected member increases, and the novel problem that the protective sheet cannot be easily peeled off from the protected member I found

  The present disclosure has been made in view of the above circumstances, and uses a pressure-sensitive adhesive layer that can reduce the pressure-sensitive adhesive force by irradiation with energy rays, and can be easily peeled off from a protected member. The main purpose is to provide seats.

  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 a fluororesin.

  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 with energy rays, and the pressure-sensitive adhesive layer provides a laminate with a protective sheet containing a fluororesin.

  The protective sheet of the present disclosure uses an adhesive layer capable of reducing the adhesive strength by irradiation of energy rays, and has an effect that it can be more easily peeled off from the protected member.

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 “on (or below)” or “on the surface” of another configuration such as another member or another region, Unless limited, this includes not only above (or directly below) other configurations, but also above (or below) other configurations, ie, above (or below) other configurations. This includes the case where another component is included in between.

  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 adhesive layer is a member containing a fluororesin.

  The protective sheet of the present disclosure will be described with reference to the drawings. FIG. 1 is a schematic cross-sectional view illustrating an example of the protective sheet of the present disclosure, and FIG. 2 is a schematic cross-sectional view illustrating an example of a laminate with a protective sheet in which the protective sheet of the present disclosure is stacked on a protected portion. 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 a fluororesin. 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.

In recent years, various products have been used as the member to be protected. For example, when the surface of the member to be protected where the protective sheet is attached is a wide area, the following new problems have been discovered. That is, when peeling the protective sheet affixed to the protected member, the force required to peel the protective sheet from the protected member increases, and the novel problem that the protective sheet cannot be easily peeled off from the protected member I found
In recent years, along with the refinement and complexity of various electronic members and the like, the thickness of protected members and the integration and miniaturization of functions have been increased. Therefore, the protected member itself and the surface of the protected member tend to be easily broken, and a protective sheet is required for the purpose of protecting the protected member. On the other hand, when the protected member itself or the surface of the protected member tends to be broken, even if the protected member is protected by the protective sheet, the protective member is removed when the protective sheet is peeled off from the protected member. There is a problem that a load is applied and the protected member is destroyed.
On the other hand, according to the present disclosure, when the adhesive layer contains a hydrophobic fluororesin, when the protective sheet is peeled off from the protected member after the protective sheet is attached to the protected member, The adhesive force can be reduced more favorably, and good peelability can be exhibited. Therefore, even when the surface of the protected member to which the protective sheet is applied has a wide area, the protective sheet is peeled from the protected member when the protective sheet attached to the protected member is peeled off. It is possible to suppress an increase in force required for this, and to easily peel the protective sheet from the member to be protected. In addition, even when the protected member itself or the surface of the protected member is easily broken, when the protective sheet is peeled off from the protected member, the load on the protected member is suppressed and the destruction of the protected member is suppressed. can do.
This is considered to be due to the fact that the surface free energy of the adhesive layer is reduced by containing the fluororesin in the adhesive layer.

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 adhesive layer has a characteristic that the adhesive strength decreases from the initial adhesive strength upon 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. The pressure-sensitive adhesive strength of the pressure-sensitive adhesive layer is based on JIS Z0237 using a pressure-sensitive adhesive substrate in which the polyester film is used as a base material and the pressure-sensitive adhesive layer in the present disclosure is formed within the thickness range described below on one side of the base material. It can be measured by laminating on the adherend under the conditions conforming to the above, and finally peeling the test piece in the length direction of the test piece at a peeling angle of 180 ° and at 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. Specifically, the haze value based on JIS K-7136 of the adhesive layer in the present disclosure is preferably 5% or less, more preferably 2% or less, and particularly preferably 1% or less. . When the haze value of the pressure-sensitive adhesive layer is within the above range, a pressure-sensitive adhesive layer having good light transmittance can be obtained. Accordingly, after the protective sheet is attached to the member to be protected, when the adhesive layer in the protective sheet is irradiated with energy rays to weaken the adhesive, the adhesive layer can be sufficiently irradiated with energy rays. 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 haze value of the adhesive layer can be measured using, for example, a haze / transmittance meter (manufactured by Murakami Color Research Laboratory, product number: HM-150).

(2) Composition The composition of the adhesive layer in the present disclosure only needs to contain a fluororesin and exhibit a predetermined adhesive force before and after irradiation with energy rays. As such an adhesive 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 a fluororesin, for example. By having the fluororesin, when the protective sheet is attached to the member to be protected and then the adhesive layer in the protective sheet is irradiated with energy, the adhesive force can be sufficiently reduced and good peelability can be obtained. In addition, the energy beam polymerizable oligomer contained in the adhesive layer in the present disclosure is cured by irradiation with energy rays, and the adhesive force can be reduced. At this time, the cohesive force is increased, so that the energy rays can be transferred to the protected member. Adhesion is less likely to occur and peeling becomes easier.

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

(A) Fluororesin The “fluororesin” in the present disclosure refers to a resin containing at least fluorine. As such a fluororesin, for example, a resin having a fluoro group in the skeleton of a polyol resin can be given. Examples of the fluorine group include a fluoroalkylene group. The fluorine content of the fluororesin, that is, the content of fluorine groups in the skeleton of the polyol resin is, for example, preferably 0.5% by mass or more, and more preferably 1% by mass or more. When the content of fluorine groups in the skeleton of the polyol resin has the above lower limit, the adhesive force is sufficiently reduced when the adhesive layer in the protective sheet is irradiated with energy after the protective sheet is applied to the member to be protected. It is possible to obtain good peelability. Further, the fluorine content of the fluororesin, that is, the fluorine group content in the skeleton of the polyol resin is, for example, preferably 100% by mass or less, and more preferably 80% by mass or less. When the content of the fluorine group in the skeleton of the polyol resin has the above upper limit, it is possible to suppress a decrease in compatibility with other compositions described later.

  The weight average molecular weight (Mw) of the polyol resin can be, for example, 20,000 or more and 400,000 or less. When the weight average molecular weight of the polyol resin is within the above range, it is possible to suppress a decrease in compatibility between the fluororesin and the solvent or other crosslinking agent.

  The fluororesin in the present disclosure is preferably a functional group-containing fluororesin. Here, the functional group-containing fluororesin refers to a fluororesin having a functional group. In the present disclosure, it is particularly preferable that the fluororesin has a crosslinkable functional group. Since the fluororesin has a crosslinkable functional group, the crosslinkable functional group crosslinks and cures with a composition to be described later, so that the adhesive strength of the adhesive layer can be reduced. Examples of the crosslinkable functional group include a hydroxyl group or an alkoxy group, and among them, a hydroxyl group is preferable. Moreover, in this indication, it is preferable to have only a hydroxyl group as a crosslinkable functional group. The hydroxyl value of the fluororesin is, for example, preferably from 5 mgKOH / g to 250 mgKOH / g, and more preferably from 10 mgKOH / g to 200 mgKOH / g. Since the hydroxyl value of a fluororesin has the said minimum, since the fall of the crosslinking density of an adhesion layer can be suppressed, it becomes possible to obtain desired adhesive force. Moreover, the fall of the compatibility of a fluororesin and a solvent can be suppressed because the hydroxyl value of a fluororesin has the said upper limit.

  In the present disclosure, the functional group-containing fluororesin is preferably a siloxane graft type polymer in which a fluororesin and siloxane are combined. Specifically, the functional group-containing fluororesin preferably has a molecular structure having a siloxane group as a graft chain in the molecular skeleton of the fluororesin. As said siloxane group, a dimethylsiloxane group is mentioned, for example. In the present disclosure, since the functional group-containing fluororesin is a siloxane graft polymer, when the protective sheet is pasted on the member to be protected and then the adhesive layer in the protective sheet is irradiated with energy, the adhesive force is sufficiently increased. It becomes possible to reduce and to obtain favorable peelability. As content rate of the dimethylsiloxane group in a fluororesin, it is preferable to set it as 5 mass% or more and 100 mass% or less, for example, and it is preferable that they are 10 mass% or more and 90 mass% or less especially. When the content of the dimethylsiloxane group in the fluororesin is within the above range, after sticking the protective sheet to the member to be protected, when the adhesive layer in the protective sheet is irradiated with energy, the adhesive force is sufficiently reduced, Good peelability can be obtained.

  Specific examples of the fluororesin as described above include, for example, commercially available products ZX-007C, ZX-001, ZX-017, ZX-022, ZX-022H, ZX-047D, ZX-058A, ZX-212, ZX-201, ZX-202 (Fluorine resin-siloxane graft type polymer manufactured by T & K TOKA), KP-911 (Fluorosilicone manufactured by Shin-Etsu Chemical Co., Ltd.), Lumiflon LF-100, LF-200, LF-302, LF- 400, LF-554, LF-600, LF-986N (manufactured by Asahi Glass Co., Ltd.) and the like.

  Further, in the present disclosure, “containing a fluororesin” means that the adhesive layer contains at least a fluororesin. For example, the content of the fluororesin contained in the adhesive layer is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, with respect to 100 parts by mass of the adhesive main agent of the adhesive layer. In particular, it is preferably 1.0 part by mass or more. Since the content of the fluororesin in the adhesive layer has the above lower limit, when the adhesive layer is irradiated with energy rays, the adhesive strength of the adhesive layer can be sufficiently reduced from the initial adhesive strength. Can be improved satisfactorily. Further, the content of the fluororesin contained in the adhesive layer is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, particularly 10 masses with respect to 100 parts by mass of the adhesive main agent of the adhesive layer. Part or less. When the content of the fluororesin in the adhesive layer has the above upper limit, the initial adhesive force of the adhesive layer is reduced due to excessive increase in the fluororesin contained in the adhesive layer, and the surface of the protected member is protected. Generation | occurrence | production of the problem that a sheet | seat cannot fully be stuck can be suppressed. Moreover, generation | occurrence | production of the malfunction that a fluororesin becomes a residue and has a bad influence on another composition can be suppressed because content of the fluororesin in an adhesion layer has the said upper limit. Furthermore, when the content of the fluororesin in the adhesive layer has the above upper limit, an increase in haze value due to the adhesive layer becoming cloudy can be suppressed.

(B) Resin (adhesive agent)
As resin used as an adhesive main ingredient, 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 mass ratio of each monomer is within the above range, it can be expected that the adhesive force is effectively reduced by irradiation with energy rays, and prevents adhesive residue from being generated on the protected member side when the adhesive layer in 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 in the present disclosure exhibits desired adhesiveness before irradiation with energy rays, and after the irradiation with energy rays in the peeling process, generation of adhesive residue on the protected member side occurs. This is because it is suppressed and can be easily peeled off.

  The pressure-sensitive adhesive composition can control the pressure-sensitive adhesive force of the pressure-sensitive adhesive layer in the present disclosure after irradiation with energy rays by adjusting the amount of the energy ray-polymerizable oligomer. The content of the energy ray polymerizable oligomer in the pressure-sensitive adhesive composition is preferably 10 parts by mass or more and 180 parts by mass or less, more preferably 20 parts by mass or more and 150 parts by mass or less, with respect to 100 parts by mass of the acrylic resin. It is preferable that If the content is within the above range, the crosslink density of the pressure-sensitive adhesive layer of the present disclosure after irradiation with energy rays is sufficient, so that desired peelability can be achieved. 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 The said polymerization initiator can use a general photoinitiator. For example, depending on the type of base material and the type of energy rays applied to the adhesive layer, an arbitrary polymerization initiator suitable for the wavelength can be selected. When the member to be protected is an optical member, the protective sheet is required to have optical characteristics. For example, it is preferable to use a photopolymerization initiator having a low yellow index value (YI value). The YI value of the photopolymerization initiator is preferably 2.0 or less, for example. The YI value can be measured using a spectral color difference meter (manufactured by Nippon Denshoku Co., Ltd., SE6000). As a commercial item of such a polymerization initiator, IRGACURE184 (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 mass or more and 10 parts by mass or less, particularly 0.5 parts by mass or more with respect to 100 parts by mass in total of the acrylic resin and the energy ray polymerizable oligomer. It is preferable that it is 7 mass parts 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 occur sufficiently, the adhesive force of the adhesive layer in the present disclosure after irradiation with energy beam becomes excessively high, and the peelability is realized. On the other hand, if the above range is exceeded, the energy beam reaches only the vicinity of the energy beam irradiation surface, and the adhesive layer in the present disclosure may be insufficiently cured. In addition, the cohesive strength of the pressure-sensitive adhesive composition may be reduced, which may cause adhesive residue. In the case where 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 mass 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 mass part or more and 20 mass parts or less with respect to 100 mass parts of acrylic resins, Among these, it is preferably 0.01 parts by mass or more and 15 parts by mass or less.
When the content of the crosslinking agent is less than the above range, the adhesive layer in the present disclosure aggregates when the adhesion between the adhesive layer and the protected member in the present disclosure is poor or when the protective sheet is peeled off from the protected member. There is a case where the adhesive remains on the protected member side due to destruction. 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 in the present disclosure after irradiation with energy rays, causing the occurrence of adhesive residue due to a decrease in cohesive force. It may become.

(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 is 10 parts by mass with respect to 100 parts by mass of the acrylic resin. It is more preferably 180 parts by mass or less, and particularly preferably 20 parts by mass or more and 150 parts by mass 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 may 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 antistatic agent, a preservative, Various additives such as an antifoaming agent and 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 be transmitted to the inside. Specifically, the thickness is 3 μm or more and 125 μm. In particular, the thickness is preferably 5 μm or more and 100 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 heat resistance. 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. For example, the protective sheet of the present disclosure may have another configuration between the adhesive layer and the substrate, and may have another configuration on the surface of the substrate opposite to the adhesive layer. . Examples of other configurations include a separator. In addition, a separator is normally arrange | positioned on the surface on the opposite side to the adhesion layer of a base material. Hereinafter, each configuration 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.

4). Use The protective sheet of this indication can be used as a member for protecting a member to be protected. Specifically, it can be used for the purpose of protection during processing of the protected member. In addition, the protective sheet of the present disclosure may be used as a member for conveying the member to be protected, or may be used as a support film. That is, the protective sheet of the present disclosure can also be used as a carrier film.

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 force is reduced from the initial adhesive force by irradiation of energy rays, and the adhesive layer is a laminate containing a fluororesin.

  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, by using the above-described protective sheet, a protective layer that can be easily peeled off from a protected member using an adhesive layer that can reduce adhesive strength by irradiation with energy rays. It can be set as a laminated body with a sheet | seat. 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 is a member laminated on a member to be protected. Further, the protective sheet has an adhesive layer and a substrate disposed on one surface of the adhesive layer, and the adhesive layer has a characteristic that the adhesive force is reduced from the initial adhesive force by irradiation with energy rays. The adhesive layer is a member containing a fluororesin.

  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. Among these, products such as FPC and PCB that require surface protection in the production process are preferable. In addition, those having terminals are preferable, for example, semiconductor chips such as IC chips and LSI chips, semiconductor packages, chip capacitors, chip resistors, transistors, inductors, etc., and electronic devices such as image display devices, Examples include building materials and automobiles. In the present disclosure, the member to be protected is preferably a product having a large surface. In the case of a protected member having a large surface, the protective sheet applied to the surface is required to have better peelability. Therefore, the effect obtained by using the protective sheet in this indication mentioned above becomes remarkable.

  The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has substantially the same configuration as the technical idea described in the claims of the present invention, and any device that exhibits the same function and effect is the present invention. It is included in the technical scope of the invention.

[Example]
(Preparation of adhesive composition)
For 100 parts by mass of acrylic pressure-sensitive adhesive (trade name: SK Dyne 1811L, manufactured by Soken Chemical Co., Ltd.), 50 parts by mass of energy beam polymerizable oligomer (trade name: NK Oligo U-10PA, manufactured by Shin-Nakamura Chemical Co., Ltd.), 1.5 parts by mass of a polymerization initiator (BASF Japan Co., Ltd., trade name: IRGACURE 819), 3 parts by mass of a fluororesin (trade name: ZX-022 made by T & K TOKA Co., Ltd.), a crosslinking agent (manufactured by Soken Chemical Co., Ltd.) L-45) 3 parts by mass is diluted with a mixed solvent of toluene and methyl ethyl ketone (trade name: KT-11, manufactured by DIC Graphics Co., Ltd.) so as to have a solid content ratio of 30%, sufficiently dispersed, and an adhesive. A composition was prepared.

(Preparation of protective sheet)
A pressure-sensitive adhesive layer is formed by coating the above-mentioned pressure-sensitive adhesive composition with a comma coat to a polyethylene terephthalate (PET) separator (trade name: E7304, manufactured by Toyobo Co., Ltd., thickness: 50 μm) so that the thickness after drying is 75 μm. did. After drying the adhesive layer, a base material (trade name: A4100 thickness: 50 μm, manufactured by Toyobo Co., Ltd.) was laminated to obtain a protective sheet of the present disclosure.

[Comparative example]
A protective sheet was obtained in the same manner as in Example except that the pressure-sensitive adhesive composition did not contain a fluororesin.

[Evaluation]
The peel strength of the protective sheets obtained in Examples and Comparative Examples was evaluated. Evaluation of peeling force was performed based on JIS Z0237 using Kapton 200H as a member to be protected. The results are shown in Table 1.

  From the results of Examples and Comparative Examples, when the adhesive layer contained a fluororesin, the surface free energy of the adhesive layer was reduced, and the adhesive strength after energy irradiation could be further reduced.

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

Claims (5)

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 a fluororesin.   The protective sheet according to claim 1, wherein the fluororesin is a functional group-containing fluororesin.   The protective sheet according to claim 2, wherein the functional group-containing fluororesin is a siloxane graft type polymer in which a fluororesin and siloxane are combined.   The protective sheet according to any one of claims 1 to 3, wherein the adhesive layer has a haze value of 5% or less in accordance with JIS K-7136. 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 a fluororesin.

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