TWI786165B - Protection sheet and layered body with protection sheet - Google Patents

Abstract

The present disclosure provides a protection sheet comprising an adhesive layer, and a substrate disposed at one surface of the adhesive layer, wherein the adhesive layer has characteristics that an adhesive force is degraded from the initial adhesive force by irradiating energy line, and the adhesive layer contains a fluorine resin.

Description

Protective sheet and laminate with protective sheet

The present invention relates to a protective sheet and a laminate with the protective sheet.

For example, in the manufacturing steps of flexible printed circuit boards (Flexible printed circuits: FPC) or printed circuit boards (Printed circuit board: PCB), there are scratches or contamination of the above-mentioned boards caused by chemicals. Deterioration of the above-mentioned substrates due to the chemicals used or the heating in the manufacturing steps. Therefore, in order to prevent the above-mentioned scratches, contamination, deterioration, etc. in the manufacturing steps of the above-mentioned substrates, a technique of using a protective sheet for protecting the surface of the above-mentioned substrates has been proposed (for example, Patent Documents 1 to 3). Such a protective sheet has, for example, a base material and an adhesive layer arranged on one surface of the base material. Moreover, a protective sheet is a member which peels off from the product which is a member to be protected finally. [Prior Art Document] [Patent Document]

[Patent Document 1] Japanese Patent No. 5361760 [Patent Document 2] Japanese Patent No. 5875318 [Patent Document 3] Japanese Patent Laid-Open No. 2017-8173

[Problem to be solved by the invention]

The protective sheet attached to the member to be protected is a member that is finally peeled off from the member to be protected. Therefore, for the protective sheet, it is preferable to use an adhesive layer having a property of peeling the protective sheet from the member to be protected. As such an adhesive layer, an adhesive layer whose adhesive force is slightly adhesive has been used previously. The above-mentioned adhesive layer with slight adhesion has the advantage of having a specific peeling force. On the other hand, since the initial adhesion is slight adhesion, it cannot be fully adhered to the protected member, and there is a problem in the function of protecting the protected member. To solve this problem, there is an adhesive layer that can reduce the adhesive force and increase the peeling force by irradiating energy rays. The adhesive layer whose adhesive force is reduced by energy ray irradiation can increase the initial adhesive force before energy ray irradiation, and can reduce the adhesive force after energy ray irradiation from the initial adhesive force. Therefore, the protective sheet using the above-mentioned adhesive layer can improve the adhesiveness to the member to be protected, and can also perform peeling from the member to be protected easily.

In recent years, various products have been used as protected members. As a result, for example, when the surface of the protected member on which the protective sheet is attached has a wide area, the following novel problems have been found. That is, when the protective sheet attached to the member to be protected is peeled off, the force required to peel the protective sheet from the member to be protected increases, and the novel problem that the protective sheet cannot be easily peeled off from the member to be protected has been found.

The present invention was established in view of the above circumstances, and its main purpose is to provide a protective sheet that can be more easily peeled off from a protected member using an adhesive layer that can reduce the adhesive force by irradiating energy rays. [Technical means to solve the problem]

The present invention provides a protective sheet comprising an adhesive layer and a base material disposed on one side of the adhesive layer, and the adhesive layer has the characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays, and the adhesive layer Contains fluororesin.

Also, in the present invention, there is provided a laminate with a protective sheet, which is formed by laminating the protective sheet and the member to be protected, wherein the protective sheet has an adhesive layer and is arranged on one surface of the adhesive layer. In the base material, the above-mentioned adhesive layer has the characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays, and the above-mentioned adhesive layer contains a fluororesin. [Effect of Invention]

The protective sheet of the present invention has the effect of enabling easier peeling from the member to be protected by using an adhesive layer that can reduce adhesive force by irradiating energy rays.

In this specification, when it is assumed that a certain component of a certain member or a certain region is positioned “on (or below)” or “surface” of other components of another member or other region, unless otherwise specified, the It includes not only the situation of being located directly above (or directly below) other components, but also the situation of being located above (or below) other components, that is, it also includes the situation of being above (or below) other components and including other components in the middle situation.

Hereinafter, embodiments of the present invention will be described with reference to the drawings and the like. However, the present invention can be implemented in many different forms, and should not be construed as limited to the description of the embodiments exemplified below. In addition, the drawings may schematically show the width, thickness, shape, etc. of each part in comparison with the embodiments for clearer description, but these are just examples and do not limit the interpretation of the present invention. In addition, in this specification and each drawing, with regard to existing drawings, the same reference numerals may be assigned to the same elements as those described above, and detailed descriptions are appropriately omitted. In addition, for the convenience of explanation, there are cases where an upper or lower phrase is used for explanation, but the up and down direction can also be reversed.

Hereinafter, the protective sheet and the laminate with the protective sheet of the present invention will be described in detail. In addition, in this invention, a "sheet" and a "film" may be used synonymously.

A. Protective sheet The protective sheet of the present invention has an adhesive layer and a base material disposed on one side of the adhesive layer, and the adhesive layer has the characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays, The above-mentioned adhesive layer contains a member of fluororesin.

The protective sheet of the present invention will be described using drawings. Fig. 1 is a schematic cross-sectional view showing an example of a protective sheet of the present invention, 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 invention is laminated on a portion to be protected. As shown in FIG. 1 , the protective sheet 10 of the present invention has an adhesive layer 1 and a substrate 2 disposed on one surface of the adhesive layer 1 . In addition, the adhesive layer 1 of the present invention has the characteristic that the adhesive force decreases from the initial adhesive force by irradiation of energy rays, and the adhesive layer 1 contains a fluororesin. The protective sheet of the present invention is a member that is attached to the surface of the protected member 20 as shown in FIG. 2 to protect the surface of the protected member 20 .

In recent years, various products have been used as protected members. As a result, for example, when the surface of the protected member on which the protective sheet is attached has a wide area, the following novel problems have been found. That is, when the protective sheet attached to the member to be protected is peeled off, the force required to peel the protective sheet from the member to be protected increases, and the novel problem that the protective sheet cannot be easily peeled off from the member to be protected has been found. In addition, in recent years, along with the precision and complexity of various electronic components, etc., thinning of protected members and integration or miniaturization of functions have been sought. Therefore, the member to be protected itself or the surface of the member to be protected tends to be easily damaged, and a protective sheet is required in order to protect the member to be protected. On the other hand, when the member to be protected itself or the surface of the member to be protected tends to be easily damaged, even if the member to be protected is protected by a protective sheet, when the protective sheet is peeled off from the member to be protected, the The problem of damage to the protected component due to the load applied to the protected component. On the other hand, according to the present invention, by making the adhesive layer contain a hydrophobic fluororesin, after the protective sheet is attached to the member to be protected, when the protective sheet is peeled off from the member to be protected, the adhesion of the adhesive layer can be reduced. The adhesive force is lowered more favorably, and good peelability can be exerted. Therefore, even when the surface of the member to be protected on which the protective sheet is attached has a wide area, when the protective sheet attached to the member to be protected is peeled off, peeling from the member to be protected can be suppressed. The increase in the force required for the protective sheet allows the protective sheet to be easily peeled off from the member to be protected. In addition, even when the protected member itself or the surface of the protected member is easily damaged, when the protective sheet is peeled off from the protected member, the load on the protected member can be suppressed, thereby suppressing damage to the protected member. The reason for this is considered to be that the surface free energy of the adhesive layer is lowered by containing the fluororesin in the adhesive layer.

1. Adhesive layer The adhesive layer of the present invention is a member arranged on one side of the substrate. Also, the adhesive layer is a member that is in close contact with the surface of the member to be protected. Here, the so-called "adhesion" refers to the concept included in "next". Adhesion is used in the sense of a temporary bonding phenomenon, whereas sticking is used in the sense of a permanent bonding phenomenon, and there is a difference in this respect (Iwanami Shoten Rikaji Jiki 5th edition). The so-called "adhesiveness" and "adhesive force" refer to the property of bonding by sensing pressure and the bonding force at that time.

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

(1) Characteristics The adhesive layer of the present invention is a layer for affixing a protective sheet to a member to be protected. In addition, the adhesive layer has a characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays. In other words, the adhesive layer has re-peelability to be peeled off from the protected member by irradiation of energy rays. Here, the term "adhesive layer showing re-peelability" means that the protective sheet can be adhered and fixed to the member to be protected by the adhesive layer, and the protected sheet can not be damaged when the protective sheet is peeled off from the member to be protected. Components to prevent paste residue and peeling on the surface of the protected component.

The adhesive layer of the present invention can be fully adhered and fixed on the surface of the protected member through the initial adhesive force. In addition, when peeling the protective sheet from the member to be protected, by irradiating the adhesive layer with energy rays, the adhesive force of the adhesive layer is reduced and the releasability is improved. Therefore, it is possible to suppress the occurrence of paste residue on the surface of the member to be protected, and it can be easily peeled off. Protect the sheet.

Here, the so-called adhesive layer of the present invention is peeled from the member to be protected by energy ray irradiation, which means that the adhesive layer of the present invention can show strong adhesiveness and be tightly fixed on the member to be protected before being irradiated by energy rays. The irradiation of energy rays significantly reduces the adhesive force and can be easily peeled off from the protected member. Specifically, the adhesive layer of the present invention preferably has an adhesive force of 0.5 N/25 mm or more and 20 N/25 mm or less before energy ray irradiation, and an adhesive force of 2.0 N/25 mm or less after energy ray irradiation. The adhesive force of the adhesive layer can be measured by using the polyester film as the base material, and using the adhesive base formed in such a way that the adhesive layer of the present invention falls within the following thickness range, to be used on one side of the above base material. The material is laminated on the substrate under the conditions of JIS Z0237, and finally the test piece is peeled off in the longitudinal direction of the test piece at a peeling angle of 180° and at room temperature. In addition, in such 180 degree peel strength measurement, the universal testing machine 5565 by Instron Corporation can be used, for example.

Examples of energy rays irradiated to the adhesive layer include electron beams, proton beams, and neutron beams in addition to light rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, and electromagnetic waves such as X-rays and γ-rays. Among these, ultraviolet rays are preferable from the viewpoint of versatility and the like.

The adhesive layer of the present invention preferably has specific light transmittance. Specifically, the haze value according to JIS K-7136 of the adhesive layer of the present invention is preferably 5% or less, particularly preferably 2% or less, particularly preferably 1% or less. When the haze value of the adhesive layer is within the above range, an adhesive layer with good light transmission can be produced. Therefore, when the adhesive layer in the protective sheet is irradiated with energy rays to weaken the adhesion after the protective sheet is attached to the member to be protected, the adhesive layer can be sufficiently irradiated with energy rays. Moreover, by making the adhesive layer have favorable light-transmittance, the light-transmittance as a protective sheet can also be improved. Therefore, when light is irradiated to the member to be protected to which the protective sheet is attached during the manufacturing process, it is possible to suppress occurrence of a problem in which light is blocked by the protective sheet. Furthermore, the haze value of the adhesive layer can be measured, for example, using a haze and light transmittance meter (manufactured by Murakami Color Technology Laboratory, product model: HM-150).

(2) Composition The composition of the adhesive layer of the present invention may contain fluororesin and exhibit specific adhesive force before and after energy ray irradiation. As such an adhesive layer, for example, in addition to a fluororesin, at least a resin (adhesive main agent), an energy ray polymerizable oligomer, and a polymerization initiator can be used. By containing the fluororesin, after the protective sheet is attached to the member to be protected, when energy is irradiated to the adhesive layer in the protective sheet, the adhesive force can be sufficiently reduced to obtain good peelability. In addition, the energy ray polymerizable oligomer contained in the adhesive layer of the present invention can be cured by irradiating energy rays, thereby reducing the adhesive force, and at this time, the cohesive force is improved, so it is difficult to cause transfer to the protected member. , peeling becomes easy.

Hereinafter, each component contained in the adhesive composition which comprises an adhesive layer is demonstrated.

(a) Fluororesin The "fluororesin" in the present invention means a resin containing at least fluorine. As such a fluororesin, the resin which has a fluorine group in the frame|skeleton of a polyol resin is mentioned, for example. As said fluorine group, a fluoroalkylene group is mentioned, for example. The fluorine content of the fluororesin, that is, the content of fluorine groups in the skeleton of the polyol resin is, for example, preferably at least 0.5% by mass, and particularly preferably at least 1% by mass. By making the fluorine group content in the skeleton of the polyol resin have the above-mentioned lower limit, the adhesive force can be sufficiently reduced when energy is irradiated to the adhesive layer in the protective sheet after the protective sheet is attached to the member to be protected. , to obtain good peelability. Also, the fluorine content of the fluororesin, that is, the content of fluorine groups in the skeleton of the polyol resin is, for example, preferably 100% by mass or less, especially preferably 80% by mass or less. By making the content rate of the fluorine group in the frame|skeleton of a polyol resin have the said upper limit, the fall of the compatibility with the following other components can be suppressed.

The weight average molecular weight (Mw) of a polyol resin can be made into 20000 or more and 400000 or less, for example. By setting the weight average molecular weight of the polyol resin within the above range, it is possible to suppress a decrease in the compatibility of the fluororesin with a solvent or other crosslinking agents.

The fluororesin of the present invention is preferably a functional group-containing fluororesin. Here, the term "functional group-containing fluororesin" refers to a fluororesin having a functional group. In the present invention, it is preferable that the fluororesin has a crosslinkable functional group. The fluororesin has a cross-linkable functional group, and the cross-linkable functional group is cross-linked with the following composition to harden, so the adhesive force of the adhesive layer can be reduced. As a crosslinkable functional group, a hydroxyl group, an alkoxy group, etc. are mentioned, for example, Among them, a hydroxyl group is preferable. Moreover, in this invention, it is preferable to have only a hydroxyl group as a crosslinkable functional group. The hydroxyl value of the fluororesin is, for example, preferably not less than 5 mgKOH/g and not more than 250 mgKOH/g, particularly preferably not less than 10 mgKOH/g and not more than 200 mgKOH/g. Since the hydroxyl value of the fluororesin has the above-mentioned lower limit, the reduction of the crosslink density of the adhesive layer can be suppressed, so that desired adhesive force can be obtained. Moreover, since the hydroxyl value of a fluororesin has the said upper limit, the fall of the compatibility of a fluororesin and a solvent can be suppressed.

In the present invention, it is preferable that the functional group-containing fluororesin is a siloxane-grafted polymer formed by compounding fluororesin and siloxane. Specifically, it is preferable that the functional group-containing fluororesin has a molecular structure in which siloxane groups are grafted chains in the molecular skeleton of the fluororesin. As said siloxane group, a dimethylsiloxane group is mentioned, for example. In the present invention, since the functional group-containing fluororesin is a siloxane-grafted polymer, after the protective sheet is attached to the member to be protected, when energy is irradiated to the adhesive layer in the protective sheet, Sufficiently reduce the adhesive force and obtain good peelability. The content of the dimethylsiloxane group in the fluororesin is, for example, preferably from 5% by mass to 100% by mass, particularly preferably from 10% by mass to 90% by mass. When the content of the dimethylsiloxane group in the fluororesin is within the above range, the adhesive layer in the protective sheet can be irradiated with energy after the protective sheet is attached to the member to be protected. Adhesive force, good peelability.

Specific examples of the aforementioned fluororesins include, for example, commercially available ZX-007C, ZX-001, ZX-017, ZX-022, ZX-022H, ZX-047D, ZX-058A, ZX- 212. ZX-201, ZX-202 (fluororesin-siloxane graft polymer manufactured by T&K TOKA), or KP-911 (fluoropolysiloxane 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.), etc.

In addition, in the present invention, "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 not less than 0.1 part by mass, preferably not less than 0.5 part by mass, particularly preferably not less than 1.0 part by mass, relative to 100 parts by mass of the main adhesive agent of the adhesive layer. When the content of the fluororesin in the adhesive layer has the above-mentioned lower limit, when the adhesive layer is irradiated with energy rays, the adhesive force possessed by the adhesive layer can be sufficiently reduced from the initial adhesive force, and the detachability of the adhesive layer can be favorably improved. Also, the content of the fluororesin contained in the adhesive layer is preferably not more than 30 parts by mass, preferably not more than 20 parts by mass, particularly preferably not more than 10 parts by mass, relative to 100 parts by mass of the main adhesive agent of the adhesive layer. By having the above-mentioned upper limit of the content of the fluororesin in the adhesive layer, it is possible to suppress the following problems: the initial adhesive force of the adhesive layer decreases due to excessive increase of the fluororesin contained in the adhesive layer, and the protective sheet cannot be sufficiently adhered on the surface of the protected component. Moreover, since the content of the fluororesin in the adhesive layer has the above-mentioned upper limit, it is possible to suppress occurrence of a problem that the fluororesin remains as a residue and adversely affects other components. Furthermore, since the content of the fluororesin in an adhesive layer has the said upper limit, the increase of the haze value by the adhesive layer being cloudy can be suppressed.

(b) Resin (adhesive base agent) Examples of resins usable as the adhesive base include acrylic resins. The acrylic resin is not particularly limited, and examples thereof include (meth)acrylate polymers obtained by homopolymerizing (meth)acrylates, (meth)acrylates as main components and (meth)acrylates ) (meth)acrylate copolymer formed by copolymerization of acrylate and other monomers, preferably (meth)acrylate copolymer. Specific examples of (meth)acrylates and other monomers include, for example, those disclosed in JP-A-2012-31316. Other monomers may be used alone or in combination of two or more. In addition, the main component here means that the copolymerization ratio is 51 mass % or more, Preferably it is 65 mass % or more.

Among them, as the above-mentioned acrylic resin, (meth)acrylate obtained by copolymerization with a hydroxyl group-containing monomer copolymerizable with the above-mentioned (meth)acrylate can be preferably used. base) acrylate copolymer, or a (meth)acrylate as a main component obtained by copolymerization with a hydroxyl-containing monomer and a carboxyl-containing monomer that can be copolymerized with the above-mentioned (meth)acrylate ( Meth)acrylate copolymer.

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

The mass average molecular weight (Mw) of the above-mentioned acrylic resin is preferably within a range of 200,000 to 1 million, and particularly preferably within a range of 200,000 to 800,000. This is because sufficient initial adhesive force can be exhibited by making the mass average molecular weight of an acrylic resin into the said range.

In addition, when the above-mentioned acrylic resin is a (meth)acrylate copolymer with a hydroxyl-containing monomer and a carboxyl-containing monomer copolymerizable with (meth)acrylate, as the above-mentioned hydroxyl-containing monomer The mass ratio to the above-mentioned carboxyl group-containing monomer is preferably in the range of 51:49 to 100:0, particularly preferably 75:25 to 100:0. The reason is that if the mass ratio of each monomer is within the above range, the effective adhesive force can be expected to be reduced by energy ray irradiation, and it is possible to prevent the adhesive layer of the present invention from occurring on the protected member side when the adhesive layer is peeled off. Paste residue.

(c) Energy ray polymerizable oligomers. Energy ray polymerizable oligomers are not particularly limited as long as they are polymerized by irradiation with energy rays. For example, photoradical polymerizability, photocationic polymerizability, photo Oligomers with anionic polymerizability, etc. Among these, photoradical polymerizable oligomers are preferred. The reasons for this are that the curing speed is fast, and various compounds can be selected from, and furthermore, physical properties such as adhesiveness before curing and peelability after curing can be easily controlled. As a photoradically polymerizable oligomer, what was disclosed by Unexamined-Japanese-Patent No. 2012-31316 is mentioned, for example, These can be used individually or in combination of 2 or more types.

The mass average molecular weight (Mw) of the energy ray polymerizable oligomer is not particularly limited, and is, for example, within the range of 250-8000, preferably within the range of 250-5000. The reason is that if the mass average molecular weight is within the above range, the adhesive layer of the present invention exhibits the desired adhesiveness before energy ray irradiation, and suppresses generation of paste on the protected member side after energy ray irradiation in the peeling step. Residue, can be easily peeled off.

Adhesive Composition By adjusting the amount of the energy ray polymerizable oligomer, the adhesive force of the adhesive layer of the present invention after energy ray irradiation can be controlled. The content of the energy ray polymerizable oligomer in the adhesive composition is preferably not less than 10 parts by mass and not more than 180 parts by mass, and preferably not less than 20 parts by mass and not more than 150 parts by mass relative to 100 parts by mass of the acrylic resin. servings or less. If the said content is in the said range, since the crosslink density of the adhesive layer of this invention after energy-beam irradiation becomes sufficient, desired peelability can be realizable. In addition, it is possible to suppress the occurrence of paste residue on the protected member side due to the decrease in the cohesive force of the adhesive composition.

(d) Polymerization initiator As the above-mentioned polymerization initiator, a general photopolymerization initiator can be used. For example, it can be selected from any polymerization initiator matching the wavelength according to the type of substrate or the type of energy ray irradiated to the adhesive layer. When the member to be protected is an optical member, since optical characteristics are required for the protective sheet, for example, it is preferable to use a photopolymerization initiator with a low yellow index value (YI value). The YI value of the photopolymerization initiator is preferably, for example, 2.0 or less. In addition, YI value can be measured using a spectrocolorimeter (SE6000 by Nippon Denshoku Co., Ltd.). As a commercial item of such a polymerization initiator, IRGACURE184 (made by BASF Japan company) etc. are mentioned, for example.

The content of the polymerization initiator in the adhesive composition is not less than 0.01 parts by mass and not more than 10 parts by mass, preferably not less than 0.5 parts by mass, based on 100 parts by mass of the total of the acrylic resin and the energy ray polymerizable oligomer And 7 mass parts or less. If the content of the polymerization initiator is less than the above-mentioned range, the polymerization reaction of the energy ray polymerizable oligomer may not be sufficiently induced, and the adhesive force of the adhesive layer of the present invention after energy ray irradiation is excessively increased, and the peelability cannot be achieved. On the other hand, if the above-mentioned range is exceeded, the energy ray may only reach the vicinity of the energy ray irradiated surface, and the curing of the adhesive layer of the present invention may become insufficient. In addition, the cohesive force of the adhesive composition decreases, resulting in paste residues. Furthermore, when an energy ray polymerizable oligomer and the following energy ray polymerizable monomer are contained in the adhesive composition, it is preferable to use The content of the polymerization initiator is within the above-mentioned range for a total of 100 parts by mass of linear polymerizable monomers.

(e) Cross-linking agent The cross-linking agent is not particularly limited as long as it cross-links at least acrylic resins, and examples thereof include isocyanate-based cross-linking agents and epoxy-based cross-linking agents. Specific examples of the isocyanate-based crosslinking agent and the epoxy-based crosslinking agent include those disclosed in JP-A-2012-31316. A crosslinking agent can be used individually or in combination of 2 or more types, It can select suitably according to the kind etc. of acrylic resin.

The content of the crosslinking agent in the adhesive composition can be appropriately set according to the type of crosslinking agent, for example, it is 0.01 to 20 parts by mass with respect to 100 parts by mass of the acrylic resin, preferably 0.01 More than 15 parts by mass and less than or equal to 15 parts by mass. If the content of the crosslinking agent does not reach the above range, the adhesion between the adhesive layer of the present invention and the member to be protected may be poor, or when the protective sheet is peeled off from the member to be protected, the adhesive layer of the present invention may be coagulated and destroyed. However, the paste remains on the protected member side. On the other hand, if the content of the cross-linking agent exceeds the above range, the above-mentioned cross-linking agent remains as an unreacted monomer in the adhesive layer of the present invention after energy ray irradiation, thereby reducing the cohesive force and resulting in paste residue. situation.

(f) Arbitrary composition The adhesive composition may contain an energy ray polymerizable monomer in addition to the above energy ray polymerizable oligomer. The reason for this is that when the energy ray is irradiated, the adhesive composition is hardened by three-dimensional crosslinking to reduce the adhesive force, and the cohesive force of the adhesive composition is increased so that it cannot be transferred to the protected member side. The energy ray polymerizable monomer is preferably a photoradical polymerizable monomer, and among them, polyfunctional acrylates or polyfunctional acrylic acid esters having three or more (meth)acryl groups in one molecule are preferred. Methacrylate. Specifically, energy ray polymerizable monomers described in JP-A-2010-173091 may be mentioned.

When the above-mentioned energy ray polymerizable oligomer and the above-mentioned energy ray polymerizable monomer are contained in the above-mentioned adhesive composition, the total content thereof is 10 parts by mass or more and 180 parts by mass with respect to 100 parts by mass of the acrylic resin. It is not more than 20 parts by mass and not more than 150 parts by mass. The reason for this is that the cross-linking density after energy ray irradiation becomes sufficient to achieve suitable peelability, and also to suppress the occurrence of paste residue on the protected member side due to the decrease in the cohesive force of the adhesive composition.

The adhesive composition may also contain silane coupling agents, adhesion imparting agents, metal chelating agents, surfactants, antioxidants, ultraviolet absorbers, pigments, dyes, colorants, antistatic agents, preservatives, defoamers, wetting agents, etc. Various additives such as moisture regulators.

(3) Others The thickness of the adhesive layer of the present invention is sufficient as long as sufficient adhesive force can be obtained and energy rays can penetrate to the inside. Specifically, it is 3 μm or more and 125 μm or less, preferably 5 μm or less. μm or more and 100 μm or less.

The adhesive composition of the present invention can be prepared by mixing the above-mentioned components and kneading or dispersing them 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 used. In addition, in order to adjust the viscosity of the adhesive composition, a diluting solvent may be added and the components may be mixed.

2. Substrate The protective sheet of the present invention has a substrate on one side of the adhesive layer. The substrate is preferably a layer that can support the adhesive layer. The base material of the present invention is a member capable of imparting heat resistance, chemical resistance, and the like to the protective sheet. Therefore, for example, in the manufacturing process of the member to be protected, in order to prevent the surface of the member to be protected from deteriorating or polluting due to heating or chemicals in the manufacturing process, when a protective sheet having a base material is attached to the surface of the member to be protected, It can well protect the protected components from heat or chemicals.

The substrate of the present invention preferably has heat resistance. For example, the heat resistance of the base material is preferably within the range of 5 ppm/°C to 50 ppm/°C, and preferably 10 ppm/°C to 30 ppm in the range of 150°C to 250°C of the base material. /°C range.

The aforementioned base material may or may not have flexibility. Examples of such substrates include inorganic substrates such as quartz glass, Pyrex (registered trademark) glass, and synthetic quartz plates; resin substrates such as resin films and optical resin plates; and the like.

As the resin that can be used for the resin base material, it is preferable to show the above-mentioned thermal expansion coefficient, and among them, in addition to the above-mentioned physical properties, it is also excellent in dimensional stability, energy ray permeability, rigidity, elongation, lamination suitability, and chemical resistance. In terms of aspects, polyimide-based resins, polyphenylene sulfide-based resins, polyester-based resins, and glass epoxy resins are preferred. The resin base material may be a single layer composed of one resin, or a multi-layer body formed by laminating two or more resin base materials.

The thickness of the substrate is not particularly limited, and can be appropriately selected according to the material, the presence or absence of flexibility, and the type of the adhesive layer.

The form of the base material is not particularly limited, and examples thereof include a plate shape, a sheet shape, a film shape, and a tape shape depending on the presence or absence of flexibility. In addition, the above-mentioned base material may be in the form of a roll or in the form of a single sheet.

The substrate preferably has transparency. Energy rays sufficient to reduce the adhesive force of the adhesive layer can be irradiated from the substrate side. The light transmittance of the base material at this time can be appropriately set as long as it can transmit a required amount of energy rays.

Regarding the base material, in order to improve the adhesion with the adhesive layer, surface treatment such as corona treatment or primer treatment may be performed on the surface where the adhesive layer is to be formed.

3. Other configurations The protective sheet of the present invention only needs to have the above-mentioned adhesive layer and base material, but may have other configurations as needed. For example, the protective sheet of the present invention may have other structures between the adhesive layer and the substrate, or may have other structures on the surface of the substrate opposite to the adhesive layer. As another structure, a separator is mentioned, for example. Furthermore, the separator is usually disposed on the surface of the substrate opposite to the adhesive layer. Each configuration will be described below.

The protective sheet of the present invention may also have a separator on the surface of the adhesive layer opposite to the substrate. The separator is provided releasably from the adhesive layer, and is peeled off from the adhesive layer when the protective sheet is attached to the member to be protected. By providing the spacer on the surface of the adhesive layer, it is possible to prevent the initial adhesive force of the adhesive layer from being reduced due to contamination or scratches on the surface of the adhesive layer during the period before the protective sheet is attached to the member to be protected through the adhesive layer. the occurrence of the situation.

As such a separator, conventionally known separators, such as a release film, release paper, release film, separator paper, release film, and release paper, can be used, for example. Specifically, polypropylene, polyethylene, a fluorine film, etc. are mentioned. In addition, the separator can be a single layer as exemplified above and has release properties, but it can also be used on one or both sides of release paper substrates such as Dolly paper, coated paper, impregnated paper, and plastic film to form a The laminate of the release layer. The mold release layer is not particularly limited as long as it is a material with mold release properties, such as silicone resin, organic resin modified silicone resin, fluororesin, amino alkyd resin, melamine resin, acrylic resin, etc. Resin, polyester resin, long chain alkyl resin, etc. Any of emulsion type, solvent type, or solvent-free type can be used for these resins.

The separator is preferably provided with easy-peeling treatment on the surface in contact with the adhesive layer.

The separator may also have moisture resistance. The reason for this is that by making the separator moisture-proof, it is possible to prevent the adhesive layer from coming into contact with moisture during the period before the protective sheet is attached to the member to be protected via the adhesive layer. The so-called moisture-proof property of the separator means that, for example, the water vapor permeability of the separator at a temperature of 40°C and a humidity of 90%RH is preferably less than 1 g/m ² /day, and preferably 0.1 g/m ² /day the following. The water vapor permeability can be measured in accordance with JIS K7129. Examples of moisture-proof separators include aluminum vapor-deposited films, silica-deposited films, aluminum foils, polyethylene films with a thickness of 0.1 mm or more, films containing moisture-proof fillers, etc. Wait.

The separator may also have light-shielding properties depending on the type of material contained in the adhesive layer or the construction environment. This is because it is possible to suppress deterioration of the adhesive layer due to irradiation of ultraviolet rays or the like until the sheet to be protected is attached to the protective member via the adhesive layer. Examples of the separator having light-shielding properties include aluminum foil separators, aluminum vapor-deposited films or paper separators, colored separators, film separators containing ultraviolet absorbers, and the like.

4. Application The protective sheet of the present invention 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 member to be protected. Moreover, the protective sheet of this invention can be used as a member for conveyance of the member to be protected, or can also be used as a support film. That is, the protective sheet of the present invention is also useful as a carrier film.

B. Laminated body with protective sheet The laminated system with protective sheet of the present invention is formed by laminating the protective sheet and the member to be protected, and the protective sheet has an adhesive layer and is arranged on one side of the adhesive layer In the base material, the above-mentioned adhesive layer has a characteristic that the adhesive force decreases from the initial adhesive force by irradiation of energy rays, and the above-mentioned adhesive layer contains a fluororesin.

The description of the usage diagram of the laminate with protective sheet of the present invention can be set to be the same as the description of Fig. 2 described in the above "A. Protective sheet", so the description here is omitted.

According to the present invention, by having the above-mentioned protective sheet, it is possible to produce a laminate with a protective sheet as follows. This laminate with a protective sheet can use an adhesive layer that can reduce the adhesive force by irradiating energy rays, making it easier to Peel off from the protected member. Furthermore, the description of the detailed effects of the present invention can be assumed to be the same as that described in the item "A. Protective sheet" above, so the description here is omitted.

1. Protective sheet The protective sheet of the present invention is a member laminated on the member to be protected. In addition, the protective sheet is a member having an adhesive layer and a base material arranged on one side of the adhesive layer, the adhesive layer has the characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays, and the adhesive layer contains Fluorine resin.

Regarding the protective sheet of the present invention, it can be assumed to be the same as that described in the item "A. Protective sheet" above, so the description here is omitted.

2. Protected member The protected member of the present invention is a member that can be laminated with the above-mentioned protective sheet, and is not particularly limited. Among them, FPC or PCB are preferred, which are products that need to protect the surface in the manufacturing process. In addition, those having terminals are preferred, for example, semiconductor chips such as IC (Integrated Circuit, integrated circuit) chips, LSI (Large Scale Integration, large-scale integrated circuits) chips, semiconductor packages, chip capacitors, chip resistors, Transistors, inductors, etc., and electronic devices such as image display devices, building materials, automobiles, and the like are exemplified. In the present invention, the member to be protected is preferably a product having a surface with a wide area. In the case of a member to be protected having a surface with a wide area, the protective sheet attached to the surface requires better peelability. Therefore, the effects obtained by using the protective sheet of the present invention described above become apparent.

In addition, this invention is not limited to the said embodiment. The above-mentioned embodiments are examples, and any one having substantially the same configuration as the technical idea described in the claims of the present invention and exerting the same effect is included in the technical scope of the present invention. [Example]

[Example] (Preparation of Adhesive Composition) Energy ray polymerizable oligomer (Shin Nakamura Chemical Co., Ltd. Co., Ltd. product name: NK Oligo U-10PA) 50 parts by mass, polymerization initiator (BASF Japan Co., Ltd. product name: IRGACURE819) 1.5 parts by mass, fluororesin (T&K TOKA Co., Ltd. product product) Name: ZX-022) 3 parts by mass, crosslinking agent (trade name: L-45 manufactured by Soken Chemical Co., Ltd.) 3 parts by mass using a mixed solvent of toluene and methyl ethyl ketone (manufactured by DIC GRAPHICS Co., Ltd. Product name: KT-11) was diluted so that the solid content ratio became 30%, and was sufficiently dispersed to prepare an adhesive composition.

(Preparation of protective sheet) The above-mentioned adhesive composition was applied to a polyethylene terephthalate (PET) separator (Toyobo Co., Ltd. Co., Ltd. product name: E7304 thickness: 50 μm), forming an adhesive layer. After the adhesive layer was dried, a substrate (trade name: A4100 manufactured by Toyobo Co., Ltd., thickness: 50 μm) was laminated to obtain the protective sheet of the present invention.

[Comparative Example] A protective sheet was obtained in the same manner as in Examples except that no fluororesin was included in the adhesive composition.

[Evaluation] The peeling force of the protective sheets obtained in Examples and Comparative Examples was evaluated. The evaluation of the peeling force was carried out in accordance with JIS Z0237 using Kapton 200H as the protected member. The results are shown in Table 1.

[Table 1]

According to the results of Examples and Comparative Examples, the surface free energy of the adhesive layer can be reduced by containing the fluororesin in the adhesive layer, and the adhesive force after energy irradiation can be further reduced.

1‧‧‧adhesive layer 2‧‧‧substrate 10‧‧‧protective sheet 20‧‧‧protected member 100‧‧‧laminated body with protective sheet

Fig. 1 is a schematic sectional view showing an example of the protective sheet of the present invention. Fig. 2 is a schematic cross-sectional view showing an example of a laminate with a protective sheet of the present invention.

1‧‧‧adhesive layer

2‧‧‧Substrate

10‧‧‧protective sheet

Claims (2)

A protective sheet comprising: an adhesive layer, and a base material arranged on one side of the adhesive layer, wherein the adhesive layer has the property of reducing the adhesive force from the initial adhesive force by irradiation of energy rays, and the adhesive layer contains fluorine Resin, resin as the main adhesive agent, energy ray polymerizable oligomer, and polymerization initiator, the content of the above polymerization initiator is relative to the total of the above resin as the main adhesive agent and the above energy ray polymerizable oligomer 100 parts by mass, not less than 0.01 parts by mass and not more than 10 parts by mass, the above-mentioned fluororesin is a functional group-containing fluororesin, and the above-mentioned functional group-containing fluororesin is a siloxane-bonded compound made of a fluororesin and siloxane. Dendritic polymer, the above-mentioned siloxane-grafted polymer has a molecular structure of a siloxane group as a graft chain in the molecular skeleton of the above-mentioned fluororesin, and the haze value of the above-mentioned adhesive layer is 5% according to JIS K-7136 the following. A laminate with a protective sheet, which is formed by laminating the protective sheet and the member to be protected, and the protective sheet has an adhesive layer and a base material arranged on one side of the adhesive layer, and the adhesive layer has The characteristic that the adhesive force is reduced from the initial adhesive force by irradiation of energy rays, The above-mentioned adhesive layer contains a fluororesin, a resin as an adhesive main agent, an energy ray polymerizable oligomer, and a polymerization initiator. The total of 100 parts by mass of oligomers is 0.01 to 10 parts by mass. The above-mentioned fluororesin is a functional group-containing fluororesin, and the above-mentioned functional group-containing fluororesin is a composite of a fluororesin and silicone The above-mentioned siloxane-grafted polymer, the above-mentioned siloxane-grafted polymer has a molecular structure of a siloxane group as a graft chain in the molecular skeleton of the above-mentioned fluororesin, and the above-mentioned adhesive layer is based on JIS K-7136 fog The degree value is less than 5%.

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