JP7185479B2 - Resin composition, resin layer, and laminated sheet - Google Patents

Description

The present invention relates to a resin composition, a resin layer, and a laminated sheet.

In general, pressure-sensitive adhesives (also referred to as pressure-sensitive adhesives; hereinafter the same) exhibit a soft solid (viscoelastic) state in a temperature range around room temperature, and have the property of adhering to adherends under pressure. Taking advantage of such properties, the pressure-sensitive adhesive is, for example, in the form of a pressure-sensitive adhesive sheet having a laminated structure (laminated sheet) having a resin layer that can function as an adhesive on one or both sides of a support, and is used in applications such as home electric appliances, automobiles, and OA equipment. Widely used in various industrial fields. Patent Documents 1 and 2 are cited as technical documents relating to adhesives or adhesive sheets.

JP-A-08-104847 WO2013/099683

Conventional laminated sheets with adhesives are suitable for rough surfaces (surfaces having uneven shapes) such as concrete, mortar, gypsum board, softwood plywood, woody cement board, calcium silicate board, tile, and fiber-reinforced cement board. and plastic adherends such as polypropylene, which is generally recognized as a low-polarity adherend, are highly difficult and tend to lack adhesive strength. For this reason, adhesives, not pressure-sensitive adhesives, have often been used for such adherends having rough surfaces. In addition, in applying an adhesive to a low-polarity adherend, it is often the case that a countermeasure such as a primer treatment is generally required. In recent years, however, there has been an increase in needs for easier bonding between adherends with rough surfaces and attachment and fixation to various other adherends including low-polarity adherends. It is strongly desired to join an adherend having a rough surface or a low-polarity adherend using a laminated sheet such as an adhesive sheet without requiring

Laminated sheets such as adhesive sheets can be used for the purpose of bonding adherends and plastic members having rough surfaces as described above. Laminated sheets such as pressure-sensitive adhesive sheets used for adherends with rough surfaces and plastic members also require holding power from the standpoint of holding a heavy object fixed to the adherend in its fixed state for a long period of time. It is said that Furthermore, since the work of bonding adherends having rough surfaces can be performed even in low-temperature environments such as outdoors in winter, laminated sheets such as pressure-sensitive adhesive sheets exhibit good adhesion to rough surfaces even at low temperatures. It is desirable to indicate

Therefore, the present invention strongly adheres to adherends that are generally easy to adhere to, such as glass, metals such as stainless steel and aluminum, and can strongly adhere to both rough surfaces and plastics. An object of the present invention is to provide a resin layer having high holding power and exhibiting good adhesiveness even at low temperatures, and a resin composition suitable for forming the resin layer. Another related object is to provide a laminated sheet comprising the resin layer.

According to this specification, a (meth)acrylic polymer having a glass transition temperature (Tg) of −40° C. or less and an adhesive of 5 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer Provided is a resin composition containing an imparting resin. The (meth)acrylic polymer includes an alkyl (meth)acrylate (A1) having a homopolymer Tg of −50° C. or less and having a branched alkyl group having 8 to 18 carbon atoms at the end of an ester group (A1), and a homopolymer (Meth)acrylate (A2) having a Tg of −40° C. or less and having an ether bond in the molecular skeleton. The monomer component contains 50 to 97% by weight of the alkyl (meth)acrylate (A1) and 3 to 50% by weight of the (meth)acrylate (A2) having an ether bond.

In addition, below, the said alkyl (meth)acrylate (A1) may be described as "monomer A1." Moreover, the (meth)acrylate (A2) having an ether bond is sometimes referred to as "monomer A2".

According to the resin composition having the above structure, the adhesion to the adherend can be improved by including a specific amount of the tackifying resin in the (meth)acrylic polymer. In addition, since the (meth)acrylic polymer is a polymer of monomer components containing the monomer A1 and the monomer A2 in a specific ratio, the resin layer exhibits high holding power and good adhesion to rough surfaces even at low temperatures. Easy to form. Therefore, by using a combination of the (meth)acrylic polymer and the specific amount of the tackifier resin, it is possible to suitably achieve both high adhesive strength and high holding power to rough surfaces and plastics, etc., and adhesiveness at low temperatures. be able to.

In the resin composition according to some aspects, the total proportion of the monomer A1 and the monomer A2 may be 75% by weight or more of all monomer components forming the (meth)acrylic polymer. The resin composition disclosed herein can be suitably implemented using a (meth)acrylic polymer that is a polymer of monomer components having such a composition.

As the monomer A2, general formula (1):
_CH2 = ^CR1 -COO-(AO) _n - ^R2 ;
A monomer represented by can be preferably used. Here, in the above general formula (1), ^R1 is a hydrogen atom or a methyl group. AO is an alkyleneoxy group having 2 to 3 carbon atoms. n is a number indicating the average number of added moles of the alkyleneoxy group, and may be, for example, 1-10. R ² is an aromatic ring or a linear, branched or alicyclic alkyl group. According to the monomer A2 having such a structure, it is easy to form a resin layer that has good adhesiveness even at low temperatures and has both adhesive strength and holding power in a well-balanced manner due to moderate cohesiveness.

In some embodiments, the tackifying resin can include at least one selected from the group consisting of rosin-based tackifying resins, terpene-based tackifying resins, petroleum-based tackifying resins, and styrene-based tackifying resins. The technique disclosed here can be suitably implemented using such a tackifying resin.

The resin composition disclosed herein may contain at least one tackifying resin having a softening point of 90°C or higher and 160°C. By using a tackifying resin having a softening point within the above range, there is a tendency to form a resin layer that has a good balance between adhesiveness and cohesiveness in a room temperature range and exhibits good adhesiveness to rough surfaces even in a low temperature range. be.

The monomer component constituting the (meth)acrylic polymer may contain at least one functional group-containing monomer selected from the group consisting of a monomer having a hydroxyl group, a monomer having a carboxyl group, and a monomer having an epoxy group. Such functional group-containing monomers can help adjust the cohesiveness and storage modulus G' of the resin layer.

The (meth)acrylic polymer preferably has a weight average molecular weight (Mw) of 350,000 or more. With a (meth)acrylic polymer having such an Mw, it is easy to obtain a resin layer having a good balance between adhesiveness to rough surfaces and plastic members and cohesiveness.

The resin composition may contain a cross-linking agent. The cross-linking agent can help adjust the cohesiveness and storage modulus G' of the resin layer. In some embodiments, the content of the cross-linking agent can be, for example, 0.01 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer. As the cross-linking agent, one or both of an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent can be preferably used.

According to this specification, a resin layer formed from any one of the resin compositions disclosed herein is provided. Such a resin layer exhibits good adhesion to adherends such as rough surfaces and plastics, has high holding power due to its moderate cohesiveness, and exhibits good adhesion even at low temperatures. can be indicative.

In some embodiments, the resin layer has a storage modulus G' at 23°C of 1.0 × 10 ⁴ Pa or more and 5.0 × 10 ⁴ Pa or less, and a storage modulus G' at -10°C. can be 3.0×10 ⁴ Pa or more and 7.0×10 ⁵ Pa or less. A resin layer having such properties is preferable because it has a good balance between adhesive strength and holding power in a room temperature range and tends to exhibit good adhesiveness even in a low temperature range.

In the following description, the storage elastic modulus G' at 23°C may be referred to as "storage elastic modulus G' (23°C)". Similarly, the storage elastic modulus G' at -10°C may be expressed as "storage elastic modulus G' (-10°C)".

In some aspects, the polymer gel fraction of the resin layer may range from 20% by weight to 95% by weight. A resin layer having a polymer gel fraction within the above range tends to favorably achieve both adhesion to rough surfaces (for example, adhesion at low temperatures) and cohesion.

According to this specification, there is provided a laminated sheet having any of the resin layers disclosed herein on at least one side of a support. Such a laminated sheet can be suitably used for bonding or fixing an adherend, for example, in a mode in which the resin layer is attached to the adherend. Non-limiting examples of the adherend include adherends having a rough surface as described above and various plastic materials. As the support, for example, a structure containing at least one of plastic film, paper, non-woven fabric, and bubble- or particle-containing sheet can be preferably used.

In some embodiments, the resin layer may have a 180° peel adhesive strength of 10 N/20 mm or more measured at a peel speed of 300 mm/min in an environment of 23°C. Hereinafter, the 180° peel adhesive strength at 23°C may be referred to as "room temperature adhesive strength". According to the technology disclosed herein, the room temperature adhesive strength can be suitably achieved by using a combination of the (meth)acrylic polymer and a specific amount of tackifying resin.

In some aspects, the resin layer may have a 180° peel adhesive strength of 5 N/20 mm or more measured at a peel speed of 300 mm/min in an environment of -10°C. Hereinafter, the 180° peel adhesive strength at −10° C. may be referred to as “low temperature adhesive strength”. The (meth)acrylic polymer is a polymer of monomer components containing monomers A1 and A2 in specific proportions, and therefore has excellent flexibility even in a low temperature range. Therefore, according to the technology disclosed herein, the low-temperature adhesion can be suitably achieved by using the (meth)acrylic polymer and a specific amount of tackifying resin in combination.

The resin composition, resin layer and laminated sheet disclosed herein can be used as, for example, an adhesive composition, an adhesive layer and an adhesive sheet.

It should be noted that an appropriate combination of the elements described above may also be included in the scope of the invention for which patent protection is sought by the present patent application.

It is a sectional view showing typically composition of a lamination sheet concerning one embodiment. FIG. 3 is a cross-sectional view schematically showing the configuration of a laminated sheet according to another embodiment; FIG. 6 is a cross-sectional view schematically showing the configuration of a laminated sheet according to still another embodiment;

Preferred embodiments of the present invention are described below. Matters other than those specifically referred to in this specification that are necessary for the implementation of the present invention are applicable based on the teaching of the implementation of the invention described in this specification and the common general knowledge at the time of filing. understandable to traders. The present invention can be implemented based on the contents disclosed in this specification and common general technical knowledge in the field.
In the drawings below, members and portions having the same function may be denoted by the same reference numerals, and redundant description may be omitted or simplified. In addition, the embodiments described in the drawings are schematics for the purpose of clearly explaining the present invention and do not necessarily represent the size or scale of the products actually provided.

Moreover, in this specification, "(meth)acrylate" is meant to comprehensively refer to acrylates and methacrylates. Similarly, in this specification, "(meth)acrylic acid" means acrylic acid and methacrylic acid, and "(meth)acryloyl group" means acryloyl group and methacryloyl group, respectively.

The resin composition disclosed herein is a polymer of monomer components containing 50 to 97% by weight of monomer A1 and 3 to 50% by weight of monomer A2, and has a Tg of −40° C. or less (meth)acrylic It contains a polymer and a tackifying resin of 5 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer.
The (meth)acrylic polymer contains a specific amount of an alkyl (meth)acrylate (monomer A1) having a branched alkyl group having 8 to 18 carbon atoms and a specific amount of a (meth)acrylate (monomer A2) having an ether bond. and obtained by polymerizing a monomer component containing Further, the homopolymers of the monomers A1 and A2 each have a low Tg, and the (meth)acrylic polymer obtained also has a low Tg. According to the resin composition containing such a (meth)acrylic polymer, due to the actions of the monomers A1 and A2, it is possible to exhibit high adhesion and high holding power to an adherend having a rough surface.

Monomer A1 has a low Tg and moderate cohesion and adhesiveness. Monomer A2 has a low Tg, moderate polarity, and favorable interaction with the adherend surface. As a result, the resin composition containing the (meth)acrylic polymer has moderate softness, cohesive force, and interaction with the interface, and has high adhesion and high adhesion to adherends having rough surfaces. It is presumed that the retention force can be exhibited.

In addition, the resin composition disclosed herein, by containing a tackifying resin, improves the wettability of a low-polar adherend and the interaction with the adherend interface, and also improves the adhesive bulk. By increasing the elastic modulus, the resin layer can be given an appropriate cohesive force. As a result, it can exhibit high adhesive strength to various adherends such as rough surfaces and plastics. The use of a tackifying resin is particularly effective for low-polar adherends such as polyolefin resins. Then, by using a specific amount of the tackifying resin in combination with the (meth)acrylic polymer, it is possible to suppress the decrease in adhesiveness at low temperatures while enjoying the effect of using the tackifying resin. It is estimated to be.

<Monomer A1>
As the monomer A1, an alkyl (meth)acrylate having a homopolymer Tg of −50° C. or lower and having a branched alkyl group having 8 to 18 carbon atoms at the end of an ester group is used. The Tg of the homopolymer of the monomer A1 is preferably −55° C. or less, more preferably −60° C. or less, from the viewpoint of increasing the adhesive strength to adherends having rough surfaces. The Tg of the homopolymer of the monomer A1 is preferably −80° C. or higher, more preferably −75° C. or higher, from the viewpoint of increasing the holding power. The number of carbon atoms in the alkyl group of the monomer A1 is preferably 8 to 16, more preferably 8 to 14, from the viewpoint of imparting appropriate softness to the resin layer and from the viewpoint of increasing the cohesive strength of the resin layer. preferable.

In the technology disclosed herein, the Tg of the homopolymer of each monomer is the numerical value described in "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989). If multiple values are listed in the above Polymer Handbook, the conventional value is used. For monomers not listed in the above Polymer Handbook, the catalog values of monomer manufacturers are used.

As the Tg of a homopolymer of a monomer that is not described in the Polymer Handbook and for which the catalog value of the monomer manufacturer is not provided, the value obtained by the following measurement method is used. That is, a reactor equipped with a thermometer, a stirrer, a nitrogen inlet tube and a reflux condenser was charged with 100 parts by weight of the monomer to be measured, 0.1 part by weight of 2,2'-azobisisobutyronitrile and acetic acid as a polymerization solvent. 200 parts by weight of ethyl is added and stirred for 1 hour while nitrogen gas is introduced. After oxygen is removed from the polymerization system in this way, the temperature is raised to 60° C. and the reaction is carried out for 12 hours. After cooling to room temperature, the homopolymer solution is cast-coated on a release liner and dried to prepare a test sample (sheet-like homopolymer) having a thickness of about 50 μm. A sample of 2 to 3 mg is taken from the obtained test sample, placed in an aluminum container, crimped and subjected to DSC measurement (Q-2000 manufactured by TA Instruments). The temperature program is −80° C. to 150° C. (measurement rate 10° C./min), and the measurement is performed under a nitrogen atmosphere (50 ml/min). The value of Tmg (midpoint glass transition temperature) is read from the obtained chart, and this value is defined as Tg of the homopolymer.

Examples of the monomer A1 include 2-ethylhexyl acrylate (8 carbon atoms, homopolymer Tg = -70°C), isooctyl acrylate (8 carbon atoms, homopolymer Tg = -58°C), isononyl acrylate (carbon atoms 9, Tg of homopolymer = -58°C), isodecyl acrylate (10 carbon atoms, Tg of homopolymer = -60°C), isomystyryl acrylate (14 carbon atoms, Tg = -56°C), isoundecyl acrylate, iso Dodecyl acrylate, isopentadecyl acrylate, isohexadecyl acrylate, isoheptadecyl acrylate, isooctadecyl acrylate, and the above-exemplified methacrylates can be exemplified. Monomer A1 can be used individually by 1 type or in combination of 2 or more types. From the standpoint of increasing the adhesive strength of the resin layer and from the standpoint of polymerization reactivity, alkyl acrylate is suitable as the monomer A1.

<Monomer A2>
As the monomer A2, a (meth)acrylate having a homopolymer Tg of −40° C. or less and having an ether bond in the molecular skeleton is used. The Tg of the homopolymer of the monomer A2 is preferably −45° C. or less, more preferably −50° C. or less, from the viewpoint of increasing the adhesive strength to adherends having rough surfaces. The Tg of the homopolymer of the monomer A2 is preferably −90° C. or higher, more preferably −80° C. or higher, from the viewpoint of enhancing adhesive strength and holding power to an adherend having a rough surface. The ether bond in the molecular skeleton of the monomer A2 means a chain ether bond and is distinguished from a cyclic ether bond such as an epoxy group or an oxetane group.

As the monomer A2, those having an unsaturated double bond of a (meth)acryloyl group and a chain ether bond can be used without particular limitation. Examples of the monomer A2 include monomers represented by the general formula (1): CH ₂ =CR ¹ --COO--(AO) _n --R ² ; Here, R ¹ in the above general formula (1) is a hydrogen atom or a methyl group. AO is an alkyleneoxy group having 2 to 3 carbon atoms. n is a number indicating the average number of added moles of the alkyleneoxy group. R ² is preferably a monovalent organic group containing no ether bond and is a hydrocarbon group. Monomer A2 can be used individually by 1 type or in combination of 2 or more types.

n in the general formula (1) can be, for example, 1-10. From the viewpoint of polarity level and polymerization reactivity, n in the general formula (1) is preferably 2 to 8, more preferably 2 to 5 in some embodiments.

R ² in the general formula (1) is preferably an unsubstituted aromatic ring or a linear, branched or alicyclic alkyl group. Examples of aromatic rings for R ² include a phenyl group and the like. Examples of straight-chain alkyl groups and branched-chain alkyl groups for R ² include isopropyl group, ethyl group, and methyl group. Examples of alicyclic alkyl groups for R ² include cyclohexyl groups and the like. R ² is preferably a straight-chain alkyl group or a branched-chain alkyl group, particularly preferably a straight-chain alkyl group, because it tends to be a homopolymer low Tg chain ether bond-containing (meth)acrylate. In addition, the number of carbon atoms in R ² is preferably 1 to 6, more preferably 1 to 5, and may be 1 to 4 or 1 to 3, since the monomer A2 tends to have an appropriate polarity.

Examples of the monomer represented by the above general formula (1) include alkyleneoxy groups in which AO has 2 carbon atoms, such as methoxypolyethyleneglycol (meth)acrylate, ethoxypolyethyleneglycol (meth)acrylate, and propoxypolyethyleneglycol (meth)acrylate. and monomers in which AO is an alkyleneoxy group having 3 carbon atoms, such as methoxypolypropyleneglycol (meth)acrylate, ethoxypolypropyleneglycol (meth)acrylate and propoxypolypropyleneglycol (meth)acrylate. From the viewpoint of polymerization reactivity, the monomer A2 in which R ¹ in the general formula (1) is a hydrogen atom is preferred. That is, monomer A2 is preferably an acrylate.

AO in the general formula (1) is preferably an alkyleneoxy group having 2 carbon atoms, that is, an oxyethylene group, from the viewpoint of having an appropriate polarity balance. Specific compounds include ethyl carbitol acrylate (ethoxyethoxyethyl acrylate) (Tg of homopolymer = -67°C), methoxytriethylene glycol acrylate (Tg of homopolymer = -57°C), and the like.

In the technology disclosed herein, the amount of monomer A1 used is suitably 50 to 97% by weight of the total monomer components forming the (meth)acrylic polymer. From the viewpoint of enhancing adhesive strength and holding power to rough surfaces, the amount of monomer A1 used is preferably 55% by weight or more, more preferably 58% by weight or more, and still more preferably 59% by weight or more of the above monomer components. be. In addition, from the viewpoint of increasing adhesive strength and holding power to rough surfaces, the amount of monomer A1 used is preferably 95% by weight or less, more preferably 93% by weight or less, and still more preferably 91% by weight of the above monomer components. It is below.

In the technology disclosed herein, the amount of monomer A2 used is suitably 3 to 50% by weight of the total monomer components forming the (meth)acrylic polymer. From the viewpoint of increasing the adhesive strength and holding power to rough surfaces, the amount of monomer A2 used is preferably 3.5% by weight or more, more preferably 4% by weight or more, based on the monomer component, and 4.5% by weight or more. % by weight or more is more preferable. In addition, from the viewpoint of increasing the adhesive strength and holding power to rough surfaces, the amount of monomer A2 used is preferably 48% by weight or less, more preferably 45% by weight or less, and still more preferably 40% by weight of the monomer component. It is below.

The total proportion of monomers A1 and A2 can be, for example, 75% by weight or more of the total monomer components. From the viewpoint of further increasing the adhesive strength and holding power to an adherend having a rough surface, the total proportion of the monomers A1 and A2 is preferably 80% by weight or more of the total monomer components, and is 85% by weight or more. is more preferable, and 90% by weight or more is even more preferable.

<Functional group-containing monomer>
The monomer component forming the (meth)acrylic polymer may contain at least one functional group-containing monomer selected from the group consisting of hydroxyl group-containing monomers, carboxyl group-containing monomers, and epoxy group-containing monomers. . By including such a functional group-containing monomer, it is possible to control the formation of a crosslinked network and intermolecular interactions while maintaining the softness of the resin layer, and it is possible to increase the cohesive force of the resin layer, resulting in higher holding power. can do. The monomer component may include, for example, a combination of a monomer having a hydroxyl group and a monomer having a carboxyl group.

As the monomer having a hydroxyl group (hydroxyl group-containing monomer), those having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and having a hydroxyl group are particularly preferred. Can be used without restrictions. Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl ( hydroxyalkyl (meth)acrylates such as meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate; (4-hydroxymethylcyclohexyl)methyl ( hydroxyalkylcycloalkane (meth)acrylate such as meth)acrylate; Other hydroxyl group-containing monomers include hydroxyethyl (meth)acrylamide, allyl alcohol, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, diethylene glycol monovinyl ether and the like. A hydroxyl group-containing monomer can be used individually by 1 type or in combination of 2 or more types. Among them, hydroxyalkyl (meth)acrylates are preferred, and 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are particularly preferred.

As the monomer having a carboxyl group (carboxyl group-containing monomer), those having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and having a carboxyl group are particularly limited. can be used without Examples of carboxyl group-containing monomers include (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid. A carboxyl group-containing monomer can be used individually by 1 type or in combination of 2 or more types. Among these, acrylic acid and methacrylic acid are preferred, and acrylic acid is particularly preferred.

As the monomer having an epoxy group (epoxy group-containing monomer), those having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group and having an epoxy group are particularly limited. can be used without Examples of epoxy group-containing monomers include glycidyl (meth)acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether, and the like. Epoxy group-containing monomers can be used singly or in combination of two or more.

In the case of using a hydroxyl group-containing monomer, the amount used is preferably 0.01% by weight or more, and 0.03% by weight or more, of the total monomer components forming the (meth)acrylic polymer, from the viewpoint of increasing the cohesive strength. is more preferable. From the viewpoint of suppressing excessive viscosity increase and gelation, the amount of the hydroxyl group-containing monomer used is suitably 20% by weight or less, preferably 15% by weight or less, and 10% by weight of the above monomer component. % or less, more preferably 5 wt % or less, even more preferably 3 wt % or less, and particularly preferably 2 wt % or less.

In the case of using a carboxyl group-containing monomer, the amount used is, from the viewpoint of increasing the cohesive strength and imparting interaction with the surface of the adherend at the molecular level, the amount of all monomer components forming the (meth)acrylic polymer. It is preferably 0.1% by weight or more, more preferably 0.2% by weight or more. The amount of the carboxyl group-containing monomer used is preferably 5% by weight or less of the monomer component, and 3% by weight or less, from the viewpoint of improving conformability to rough surfaces and maintaining high adhesive strength at low temperatures. It is more preferably 2.6% by weight or less, and particularly preferably 2.2% by weight or less.

In the case of using an epoxy group-containing monomer, the amount used is preferably 0.1% by weight or more of the total monomer components forming the (meth)acrylic polymer, and 0.2% by weight or more, from the viewpoint of increasing cohesive strength. is more preferable. The amount of the epoxy group-containing monomer used is preferably 1% by weight or less, more preferably 0.5% by weight or less, based on the above monomer component, from the viewpoint of suppressing gelation and increase in viscosity. However, this is not the case when the (meth)acrylic polymer is a graft polymer.

When a hydroxyl group-containing monomer and a carboxyl group-containing monomer are used together as the functional group-containing monomer, the weight ratio of the hydroxyl group-containing monomer to the carboxyl group-containing monomer (hydroxyl group-containing monomer/carboxyl group-containing monomer) is 0.01 or more is preferable, 0.02 or more is more preferable, and 1.0 or less is preferable, and 0.50 or less is more preferable from the viewpoint of increasing the adhesive strength to the adherend.

<Copolymerization monomer>
The monomer component forming the (meth)acrylic polymer is, in addition to the above-described monomer A1 and monomer A2, optionally a copolymerizable monomer other than the functional group-containing monomer (monomer A1 or monomer A2) ) may be included. The copolymerizable monomers can be used singly or in combination of two or more.

Examples of the copolymerizable monomer include monomers represented by general formula (2): CH ₂ =CR ³ --COO--R ⁴ ; Here, R ³ in the above general formula (2) is a hydrogen atom or a methyl group. R ⁴ is an unsubstituted or substituted alkyl group having 1 to 24 carbon atoms.

The unsubstituted alkyl group or substituted alkyl group having 1 to 24 carbon atoms (more preferably 1 to 18 carbon atoms) as R ⁴ in the general formula (2) is a linear or branched alkyl group. , or a cyclic cycloalkyl group. Specifically, R ⁴ can be a linear alkyl group having 1 to 18 carbon atoms, a branched alkyl group having 3 to 7 carbon atoms, a cyclic alkyl group, and the like. When R ⁴ is a substituted alkyl group, preferred examples of the substituent include an aryl group having 3 to 7 carbon atoms and an aryloxy group having 3 to 7 carbon atoms. The aryl group is not particularly limited, but is preferably a phenyl group, for example.

Examples of the monomer represented by the general formula (2) include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) Acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, isoamyl (meth)acrylate, n-octyl (meth)acrylate, n -nonyl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 3,3,5-trimethylcyclohexyl (meth)acrylate, isobornyl (meth)acrylate, terpene (meth)acrylate , dicyclopentanyl (meth)acrylate and the like.

Examples of the copolymerizable monomer include vinyl monomers such as vinyl acetate, vinyl propionate, styrene, α-methylstyrene, N-vinylcaprolactam, and N-vinylpyrrolidone; tetrahydrofurfuryl (meth)acrylate, fluorine (Meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate (meth) acrylic acid ester monomers; (meth) acrylonitrile and other cyano group-containing monomers; other amide group-containing monomers, amino group-containing monomers, Imido group-containing monomers, N-acryloylmorpholine, vinyl ether monomers and the like can also be used.

Other examples of the copolymerizable monomers include silane-based monomers containing silicon atoms. Examples of silane monomers include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane and the like.

The amount of the copolymerizable monomer used is preferably 20% by weight or less, more preferably 15% by weight or less, of the total monomer components forming the (meth)acrylic polymer. If the content of the copolymerizable monomer exceeds 20% by weight, for example, the adhesion to rough surfaces may decrease.

<Polyfunctional Monomer>
The monomer component forming the (meth)acrylic polymer may optionally contain a polyfunctional monomer for the purpose of adjusting the cohesive force. A polyfunctional monomer can be used individually by 1 type or in combination of 2 or more types.

The polyfunctional monomer is a monomer having at least two polymerizable functional groups ((meth)acryloyl group, vinyl group, etc.) having an unsaturated double bond, for example, (poly)ethylene glycol di(meth)acrylate , (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, 1,2- Ethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, tetramethylolmethane tri(meth)acrylate, etc. ester compound of polyhydric alcohol and (meth)acrylic acid; allyl (meth)acrylate, vinyl (meth)acrylate, divinylbenzene, epoxy acrylate, polyester acrylate, urethane acrylate, butyl di(meth)acrylate, hexyl di(meth)acrylate etc. Among these, trimethylolpropane tri(meth)acrylate, hexanediol di(meth)acrylate, and dipentaerythritol hexa(meth)acrylate are preferable.

The polyfunctional monomer can be used in an amount of 5% by weight or less with respect to all monomer components forming the (meth)acrylic polymer. Although the polyfunctional monomer varies depending on its molecular weight, the number of functional groups, etc., it is preferably 3% by weight or less, more preferably 2% by weight or less, based on the total monomer components forming the (meth)acrylic polymer. If the content of the polyfunctional monomer is too high, for example, the modulus of elasticity of the resin composition may become too high, and the adhesion to rough surfaces (especially the adhesion at low temperatures) may decrease.

<(Meth)acrylic polymer and method for producing the same>
The (meth)acrylic polymer has a Tg of -40°C or lower. The Tg of the (meth)acrylic polymer is preferably −45° C. or less, more preferably −50° C. or less, from the viewpoint of increasing the adhesive strength to adherends having rough surfaces. From the viewpoint of enhancing adhesion at low temperatures, in some embodiments, the (meth)acrylic polymer preferably has a Tg of -55°C or lower, more preferably -57°C or lower, and even more preferably -60°C or lower. In addition, the Tg of the (meth)acrylic polymer is preferably −85° C. or higher, more preferably −80° C. or higher, from the viewpoint of increasing the adhesive strength and holding power to an adherend having a rough surface. preferable.

Here, the Tg of the (meth)acrylic polymer is a theoretical value calculated from the following Fox formula based on the composition of the monomer components constituting the (meth)acrylic polymer.
Fox formula: 1/Tg= _W1 /Tg1+ _W2 / _Tg2 + _... + _Wn / _Tgn
[In the formula, Tg is the glass transition temperature (unit: K) of the (meth)acrylic polymer, and Tg _i (i = 1, 2, ... n) is the temperature at which the monomer i forms a homopolymer. It is the glass transition temperature (unit: K), and W _i (i=1, 2, . . . n) represents the mass fraction of monomer i in all monomer components. ]

The method for producing the (meth)acrylic polymer is not particularly limited, and a known production method can be appropriately selected. For example, various radical polymerization methods such as solution polymerization, radiation polymerization by irradiation with electron beams or ultraviolet rays (UV), bulk polymerization, and emulsion polymerization can be used. The (meth)acrylic polymer to be obtained may be any of random copolymers, block copolymers, graft copolymers, and the like.

For the radical polymerization, known polymerization initiators, chain transfer agents, emulsifiers, polymerization solvents, and the like can be used as necessary, depending on the mode of polymerization. The Mw of the (meth)acrylic polymer can be controlled by the polymerization initiator, the chain transfer agent, the reaction conditions, etc., and the amount used is appropriately adjusted according to these types.

In solution polymerization, for example, ethyl acetate, toluene, a mixed solvent thereof, and the like can be used as a polymerization solvent. The above-mentioned solution polymerization is carried out, for example, under an inert gas stream such as nitrogen, adding a polymerization initiator, and generally performing the reaction at a temperature of about 50 to 70° C. for about 5 to 30 hours.

Examples of the polymerization initiator include 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis(2-amidinopropane) dihydrochloride, 2,2′-azobis[2-(5 -methyl-2-imidazolin-2-yl)propane]dihydrochloride, 2,2'-azobis(2-methylpropionamidine) disulfate, 2,2'-azobis(N,N'-dimethyleneisobutyramidine) , 2,2′-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (manufactured by Wako Pure Chemical Industries, Ltd., VA-057) and other azo initiators; potassium persulfate, ammonium persulfate, etc. persulfate of; di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butyl peroxyneodecanoate, t-hexyl peroxypivalate, t-butyl peroxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate , di(4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, etc. Peroxide-based initiators; Redox-based initiators combining peroxides and reducing agents, such as combinations of persulfate and sodium hydrogen sulfite, and combinations of peroxides and sodium ascorbate; , but not limited to these. In some embodiments, AIBN may preferably be used as the polymerization initiator.

A polymerization initiator can be used individually by 1 type or in combination of 2 or more types. The amount of the polymerization initiator to be used is preferably about 0.005 to 1 part by weight, more preferably about 0.01 to 0.5 part by weight, based on 100 parts by weight of the monomer component. preferable.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol and the like. A chain transfer agent can be used individually by 1 type or in combination of 2 or more types. The amount of the chain transfer agent to be used is usually about 0.1 part by weight or less per 100 parts by weight of the total amount of the monomer components. Alternatively, no chain transfer agent may be used.

Emulsion polymerizations are typically carried out using known emulsifiers. Examples of emulsifiers include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, and sodium polyoxyethylene alkylphenyl ether sulfate; Nonionic emulsifiers such as phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block polymer;

As the emulsifier, an emulsifier into which a radically polymerizable functional group such as a propenyl group or an allyl ether group has been introduced may be used. An emulsifier into which such a polymerizable functional group has been introduced is generally called a reactive emulsifier. Specific examples of reactive emulsifiers include Aqualon HS-10, HS-20, KH-10, BC-05, BC-10, and BC-20 (all manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), Adekaria Soap SE10N. (manufactured by ADEKA) and the like. Reactive emulsifiers are preferred because they are incorporated into the polymer chain after polymerization, resulting in improved water resistance.

An emulsifier can be used individually by 1 type or in combination of 2 or more types. The amount of the emulsifier to be used is usually about 0.3 to 5 parts by weight per 100 parts by weight of the monomer component. It is preferable to

When the (meth)acrylic polymer is produced by radiation polymerization, it can be produced by polymerizing the above monomer components by irradiating them with radiation such as electron beams and UV rays. When the radiation polymerization is carried out with an electron beam, it is not particularly necessary to include a photopolymerization initiator in the monomer component. When the radiation polymerization is performed by UV polymerization, it is preferable to incorporate a photopolymerization initiator into the monomer component from the viewpoint of shortening the polymerization time. A photoinitiator can be used individually by 1 type or in combination of 2 or more types.

The photopolymerization initiator is not particularly limited as long as it can initiate photopolymerization, and can be appropriately selected from various known photopolymerization initiators and used. For example, benzoin ether-based, acetophenone-based, α-ketol-based, photoactive oxime-based, benzoin-based, benzyl-based, benzophenone-based, ketal-based, and thioxanthone-based photopolymerization initiators can be used. The amount of the photopolymerization initiator used is 0.05 to 1.5 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the monomer component.

In some embodiments, the (meth)acrylic polymer preferably has a weight average molecular weight (Mw) of 350,000 or more. Mw of the (meth)acrylic polymer is more preferably 400,000 or more, more preferably 500,000 or more, from the viewpoint of enhancing the durability and cohesion of the resin layer. The Mw of the (meth)acrylic polymer is preferably 3,000,000 or less, more preferably 2,500,000 or less, from the viewpoint of enhancing the adhesiveness at low temperatures and suppressing the viscosity increase of the resin composition. , is more preferably 2,000,000 or less, even more preferably 1,500,000 or less, and even more preferably 1,200,000 or less.

The Mw of the (meth)acrylic polymer can be measured by GPC (gel permeation chromatography) under the following conditions and calculated by polystyrene conversion. A sample for GPC is obtained by dissolving the sample in tetrahydrofuran (THF) to obtain a 0.1% by weight solution, allowing the solution to stand overnight, and then filtering through a 0.45 μm membrane filter. A similar method is used in the examples described later.
・ Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
・Column: GM7000HXL+GMHXL+GMHXL manufactured by Tosoh Corporation
・Column size: each 7.8 mmφ×30 cm (total 90 cm)
・ Sample concentration: 0.1% by weight (THF solution)
・ Eluent: THF
・Flow rate: 0.8 ml/min
・Inlet pressure: 1.6 MPa
・Detector: Differential refractometer (RI)
・Column temperature: 40°C
・Injection volume: 100 μl
・Standard sample: Polystyrene

<Crosslinking agent>
The resin composition disclosed herein may optionally contain a cross-linking agent. Examples of cross-linking agents include isocyanate cross-linking agents, epoxy cross-linking agents, silicone cross-linking agents, oxazoline cross-linking agents, aziridine cross-linking agents, silane cross-linking agents, alkyl etherified melamine cross-linking agents, and metal chelate cross-linking agents. cross-linking agents such as, but not limited to, peroxides. Suitable examples of the cross-linking agent include isocyanate-based cross-linking agents and epoxy-based cross-linking agents. An isocyanate-based cross-linking agent and an epoxy-based cross-linking agent may be used in combination.

The above-mentioned cross-linking agents can be used singly or in combination of two or more. The amount of the cross-linking agent used is preferably in the range of 0.005 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer. The content of the cross-linking agent with respect to 100 parts by weight of the (meth)acrylic polymer is preferably 0.01 parts by weight or more and 4 parts by weight or less, more preferably 0.02 parts by weight or more and 3 parts by weight or less, More preferably, it is 0.05 parts by weight or more and 2 parts by weight or less. Moreover, you may use the said polyfunctional monomer as a crosslinking agent. In this case, the amount of the polyfunctional monomer used is preferably in the range of 0.001 parts by weight or more and 2 parts by weight or less relative to 100 parts by weight of the (meth)acrylic polymer, and is preferably 0.003 parts by weight or more. The range of 1 part by weight or less is more preferable.

As the isocyanate-based cross-linking agent, a compound having two or more isocyanate groups in one molecule (which may be an isocyanate regenerative functional group in which the isocyanate group is temporarily protected by a blocking agent or a quantization, etc.) is used. can be done. Examples of isocyanate-based cross-linking agents include aromatic isocyanates such as tolylene diisocyanate and xylene diisocyanate, alicyclic isocyanates such as isophorone diisocyanate, and aliphatic isocyanates such as hexamethylene diisocyanate.

More specifically, the isocyanate-based cross-linking agent includes, for example, lower aliphatic polyisocyanates such as butylene diisocyanate and hexamethylene diisocyanate; alicyclic isocyanates such as cyclopentylene diisocyanate, cyclohexylene diisocyanate and isophorone diisocyanate; 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate, aromatic diisocyanates such as polymethylene polyphenyl isocyanate, trimethylolpropane/tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, product name: Coronate L), trimethylolpropane/hexamethylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name: Coronate HL), isocyanurate of hexamethylene diisocyanate (manufactured by Tosoh Corporation, trade name: Coronate HX), etc. Isocyanate adduct, trimethylolpropane adduct of xylylene diisocyanate (manufactured by Mitsui Chemicals, trade name: Takenate D110N), trimethylolpropane adduct of xylylene diisocyanate (manufactured by Mitsui Chemicals, trade name: Takenate D120N), isophorone diisocyanate Trimethylolpropane adduct of (manufactured by Mitsui Chemicals, trade name: Takenate D140N), trimethylolpropane adduct of hexamethylene diisocyanate (manufactured by Mitsui Chemicals, trade name: Takenate D160N), polyether polyisocyanate, polyester polyisocyanate, and adducts of these with various polyols, and polyisocyanates multifunctionalized with isocyanurate bonds, biuret bonds, allophanate bonds, and the like. Among these, aromatic isocyanates and alicyclic isocyanates are preferably used in order to develop properties relating to adhesive strength and holding power in a well-balanced manner.

The isocyanate-based cross-linking agents may be used singly or in combination of two or more. The amount of the isocyanate cross-linking agent used can be, for example, 0.01 parts by weight or more and 10 parts by weight or less, usually 0.03 parts by weight or more and 8 parts by weight or less, relative to 100 parts by weight of the (meth)acrylic polymer. and more preferably 0.05 to 6 parts by weight or 0.08 to 5 parts by weight. The amount of the isocyanate cross-linking agent to be used can be appropriately set in consideration of cohesive strength, prevention of peeling in a durability test, and the like.

From the viewpoint of making it easier to exhibit good adhesion even at low temperatures in a composition containing a tackifying resin, in some embodiments, the amount of the isocyanate cross-linking agent used relative to 100 parts by weight of the (meth)acrylic polymer is 5.0 parts by weight. may be less than, preferably less than 4.0 parts by weight, more preferably less than 3.0 parts by weight, even more preferably less than 2.0 parts by weight, less than 1.5 parts by weight More preferably, it is less than 1.0 parts by weight. Further, from the viewpoint of facilitating good holding power in a composition containing a tackifying resin, in some embodiments, the amount of the isocyanate cross-linking agent used is preferably, for example, 0.10 parts by weight or more. .20 parts by weight or more is more preferable.

In the case of containing an isocyanate-based cross-linking agent in an aqueous resin composition (for example, a resin composition containing an aqueous dispersion of a (meth)acrylic polymer prepared by emulsion polymerization), the isocyanate-based cross-linking agent and water From the viewpoint of suppressing the reaction with and enhancing the storage stability of the resin composition, it is possible to use an isocyanate cross-linking agent whose isocyanate group is temporarily protected by a blocking agent, quantization, or the like. Alternatively, an isocyanate-based cross-linking agent may not be used.

As the epoxy-based cross-linking agent, a polyfunctional epoxy compound having two or more epoxy groups in one molecule can be used. Examples of epoxy-based cross-linking agents include N,N,N',N'-tetraglycidyl-m-xylenediamine, diglycidylaniline, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1, 6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, glycerol polyglycidyl ether, penta erythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipate diglycidyl ester, o-phthalate diglycidyl ester, triglycidyl-tris(2-hydroxyethyl)isocyanurate, In addition to resorcinol diglycidyl ether and bisphenol-S-diglycidyl ether, epoxy-based resins having two or more epoxy groups in the molecule can be used. Examples of commercially available epoxy-based cross-linking agents include trade names "Tetrad C" and "Tetrad X" manufactured by Mitsubishi Gas Chemical Company, Inc.

Epoxy-based cross-linking agents may be used alone or in combination of two or more. The amount of the epoxy-based cross-linking agent used can be, for example, about 0.005 parts by weight or more and 1 part by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer, and 0.01 parts by weight or more and 0.5 parts by weight. It may be about 0.015 parts by weight or more and 0.3 parts by weight or less. The amount of the epoxy-based cross-linking agent to be used can be appropriately set in consideration of cohesive strength, durability, and the like.

Any peroxide can be used as appropriate as long as it can generate radical active species by heating to promote cross-linking of the (meth)acrylic polymer of the resin composition. In view of this, it is preferable to use a peroxide with a 1-minute half-life temperature of 80°C to 160°C, more preferably 90°C to 140°C.

Examples of the peroxide include di(2-ethylhexyl) peroxydicarbonate (1 minute half-life temperature: 90.6° C.), di(4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 ° C. ), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C.), t-butyl peroxypivalate (1 minute half-life temperature: 110.3 ° C.), dilauroyl peroxide (1 minute half-life life temperature: 116.4 ° C.), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C.), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1-minute half-life temperature: 124.3°C), di(4-methylbenzoyl) peroxide (1-minute half-life temperature: 128.2°C), dibenzoyl peroxide (1-minute half-life temperature: 130.0°C) , t-butyl peroxyisobutyrate (1 minute half-life temperature: 136.1 ° C.), 1,1-di (t-hexylperoxy) cyclohexane (1 minute half-life temperature: 149.2 ° C.), etc. be done. Among them, di(4-t-butylcyclohexyl)peroxydicarbonate (1-minute half-life temperature: 92.1° C.) and dilauroyl peroxide (1-minute half-life temperature: 116.0° C.) are particularly effective in cross-linking reaction efficiency. 4° C.), dibenzoyl peroxide (1-minute half-life temperature: 130.0° C.) and the like are preferably used.

The half-life of the peroxide is an index representing the rate of decomposition of the peroxide, and refers to the time required for the residual amount of the peroxide to be halved. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in manufacturer catalogs. (May 2003)”, etc.

The above peroxides may be used singly or in combination of two or more. The amount of the peroxide used is usually about 0.02 to 2 parts by weight, preferably about 0.05 to 1 part by weight, per 100 parts by weight of the (meth)acrylic polymer. preferably. The amount of peroxide to be used is appropriately selected within this range in order to adjust workability, reworkability, crosslink stability, peelability, and the like.

The amount of peroxide remaining after the reaction treatment can be determined, for example, by measuring the amount of peroxide decomposition by HPLC (high performance liquid chromatography). Specifically, for example, about 0.2 g of a sample is collected from the resin layer after the reaction treatment, immersed in 10 ml of ethyl acetate, shaken and extracted with a shaker at 25° C. and 120 rpm for 3 hours, then room temperature. for 3 days. Then, 10 ml of acetonitrile was added, shaken at 120 rpm at 25° C. for 30 minutes, filtered through a membrane filter (0.45 μm), and about 10 μl of the extract obtained was injected into HPLC for analysis. can be the amount of peroxide.

As the metal chelate-based cross-linking agent, a polyfunctional metal chelate in which a polyvalent metal is covalently or coordinately bonded to an atom in an organic compound can be used. Examples of polyvalent metals include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, and Ti. is mentioned. An oxygen atom etc. are mentioned as an atom in such an organic compound which covalently bonds or coordinate-bonds with a polyvalent metal. Examples of the organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

<Tackifying resin>
The tackifying resin used in the resin composition disclosed herein is not particularly limited, and can be appropriately selected from known tackifying resins. For example, rosin-based tackifying resin, terpene-based tackifying resin, phenol-based tackifying resin, hydrocarbon-based tackifying resin, ketone-based tackifying resin, polyamide-based tackifying resin, epoxy-based tackifying resin, elastomer-based tackifying resin etc. The tackifying resin can be used singly or in combination of two or more.

Examples of rosin-based tackifying resins include unmodified rosins (fresh rosins) such as gum rosin, wood rosin, tall oil rosin, and modified rosins obtained by modifying these unmodified rosins by polymerization, disproportionation, hydrogenation, etc. polymerized rosin, stabilized rosin, disproportionated rosin, completely hydrogenated rosin, partially hydrogenated rosin, and other chemically modified rosins), and various rosin derivatives.
Examples of the rosin derivatives include rosin phenolic resins obtained by adding phenol to rosins (unmodified rosin, modified rosin, various rosin derivatives, etc.) with an acid catalyst and thermally polymerizing;
Ester compounds of rosin (undenatured rosin ester) obtained by esterifying undenatured rosin with alcohols, denatured rosin such as polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc. rosin ester resins such as ester compounds of modified rosin esterified by (polymerized rosin ester, stabilized rosin ester, disproportionated rosin ester, fully hydrogenated rosin ester, partially hydrogenated rosin ester, etc.);
Unsaturated fatty acid modified rosin resin obtained by modifying unmodified rosin or modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.) with unsaturated fatty acid;
Unsaturated fatty acid-modified rosin ester-based resin obtained by modifying rosin ester-based resin with unsaturated fatty acid;
Carboxyl groups in unmodified rosin, modified rosin (polymerized rosin, stabilized rosin, disproportionated rosin, fully hydrogenated rosin, partially hydrogenated rosin, etc.), unsaturated fatty acid modified rosin resin and unsaturated fatty acid modified rosin ester resin A rosin alcohol resin obtained by reducing the
Unmodified rosin, modified rosin, and metal salts of rosin-based resins such as various rosin derivatives (especially rosin ester-based resins);

Terpene-based tackifying resins include, for example, terpene-based resins such as α-pinene polymer, β-pinene polymer, and dipentene polymer, and modifications of these terpene-based resins (phenol modification, aromatic modification, hydrogenation modification modified terpene-based resins (for example, terpene-phenolic resins, styrene-modified terpene-based resins, aromatic modified terpene-based resins, hydrogenated terpene-based resins, etc.).

Examples of phenol-based tackifying resins include condensation products of various phenols (e.g., phenol, m-cresol, 3,5-xylenol, p-alkylphenol, resorcinol) and formaldehyde (e.g., alkylphenol-based resins, xylene formaldehyde resins, etc.), resoles obtained by the addition reaction of the above phenols and formaldehyde with an alkali catalyst, and novolaks obtained by the condensation reaction of the above phenols and formaldehyde with an acid catalyst.

Examples of hydrocarbon-based tackifying resins include petroleum-based tackifying resins and styrene-based tackifying resins. More specifically, aliphatic hydrocarbon resins, aromatic hydrocarbon resins, aliphatic cyclic hydrocarbon resins, aliphatic/aromatic petroleum resins (styrene-olefin copolymers, etc.), aliphatic/ Alicyclic petroleum resins, hydrogenated hydrocarbon resins, coumarone-based resins, coumarone-indene-based resins, and the like.

Examples of commercially available rosin-based tackifying resins that can be preferably used include Pencel series, which are rosin ester-based tackifying resins manufactured by Arakawa Chemical Industries, Ltd., such as "Pencel AZ", "Pencel D-125", and "Pencel D- 135”, “Pensel D-160”, “Pensel KK”, “Pensel C” and the like, but are not limited to these.

Commercially available terpene-based tackifying resins that can be preferably used include trade names "YS Polyster T130", "YS Polyster T115", "YS Polyster S145", "YS Polyster G125", and "YS Polyster N125" manufactured by Yasuhara Chemical Co., Ltd. , "YS Polyster U115", trade names "Tamanol 803L" and "Tamanol 901" manufactured by Arakawa Chemical Industries, Ltd., trade names manufactured by Sumitomo Bakelite Co., Ltd. "Sumilite Resin PR-12603", Harima Chemicals Co., Ltd. Haritak series, etc. are exemplified, but not limited to these.

It is appropriate to use the tackifying resin in an amount of 5 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer. By setting the amount of the tackifier resin used to 5 parts by weight or more, the advantageous effects of using the tackifier resin can be suitably exhibited. In some embodiments, the amount of the tackifying resin used relative to 100 parts by weight of the (meth)acrylic polymer is, for example, preferably 7 parts by weight or more, more preferably 10 parts by weight or more. Further, by setting the amount of the tackifying resin to 40 parts by weight or less, it is possible to obtain the advantageous effects of using the tackifying resin while suppressing the decrease in adhesiveness at low temperatures. In some embodiments, the amount of the tackifying resin used is, for example, preferably 38 parts by weight or less, more preferably 35 parts by weight or less, relative to 100 parts by weight of the (meth)acrylic polymer.

The softening point (softening temperature) of the tackifying resin is not particularly limited. From the viewpoint of easily exhibiting good adhesiveness even at low temperatures, in some embodiments, the softening point of the tackifier resin is preferably 180° C. or lower, more preferably 160° C. or lower, 150° C. or lower, and 140° C. or lower. , or 135° C. or lower. In addition, from the viewpoint of suppressing a decrease in cohesive strength in a temperature range of room temperature or higher, in some embodiments, the softening point of the tackifying resin is suitably 60° C. or higher, and is 80° C. or higher. is preferred, and 90° C. or higher is more preferred. The technology disclosed herein can be suitably practiced with a tackifying resin having a softening point in the range of 90°C to 160°C, 90°C to 150°C, or 90°C to 140°C. When using a plurality of types of tackifying resins with different softening points, at least one type of tackifying resin preferably has the above softening point. For example, it is preferable that 50% by weight or more, 70% by weight or more, 90% by weight or more, or 100% by weight of the total amount of the tackifying resin has the softening point. For the softening point of the tackifying resin, the value described in the manufacturer's catalog can be adopted, or it can be measured based on the softening point test method (ring and ball method) specified in JIS K2207.

<(Meth) acrylic oligomer>
The resin composition disclosed herein may contain a (meth)acrylic oligomer. Here, the (meth)acrylic oligomer refers to a polymer containing monomer units derived from a monomer having a (meth)acryloyl group (i.e., (meth)acrylic monomer) in the polymer structure, typically It refers to a polymer containing the monomer units in a proportion of more than 50% by weight. As the (meth)acrylic oligomer, a polymer having a higher Tg and a lower Mw than the (meth)acrylic polymer can be preferably used. The (meth)acrylic oligomer can help improve adhesion to adherends such as rough surfaces and plastics.

The (meth)acrylic oligomer preferably has a Tg of about 0°C to 300°C, preferably about 20°C to 300°C, more preferably about 40°C to 300°C. If the Tg is less than about 0° C., the cohesive force of the resin layer may be lowered in the temperature range of room temperature or higher, and the retention properties and adhesiveness at high temperatures may be lowered. Incidentally, the Tg of the (meth)acrylic oligomer is a theoretical value calculated based on the Fox formula, like the Tg of the (meth)acrylic polymer.

Mw of the (meth)acrylic oligomer may be, for example, 1,000 or more and less than 30,000, preferably 1,500 or more and less than 20,000, and more preferably 2,000 or more and less than 10,000. If Mw is 30,000 or more, the effect of improving adhesive strength may not be sufficiently obtained. Moreover, when Mw is less than 1000, the molecular weight becomes low, which may cause a decrease in adhesive strength and holding properties.
The Mw of the (meth)acrylic oligomer can be obtained as a polystyrene-equivalent value based on GPC. Specifically, measurement can be performed using HPLC8020 manufactured by Tosoh Corporation, using two columns of TSKgelGMH-H (20), and using THF solvent at a flow rate of about 0.5 ml/min.

Examples of monomers constituting the (meth)acrylic oligomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, isobutyl (meth) acrylates, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, Such as octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate Alkyl (meth)acrylates; esters of (meth)acrylic acid and alicyclic alcohols such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate; phenyl (meth)acrylate, benzyl Aryl (meth)acrylates such as (meth)acrylates; (meth)acrylates obtained from terpene compound derivative alcohols; and other (meth)acrylates can be mentioned. Such (meth)acrylates can be used alone or in combination of two or more.

The (meth)acrylic oligomer is an alkyl (meth)acrylate having a branched alkyl group such as isobutyl (meth)acrylate or t-butyl (meth)acrylate; cyclohexyl (meth)acrylate or isobornyl (meth)acrylate. Cyclic structures such as esters of (meth)acrylic acid and alicyclic alcohols such as acrylate dicyclopentanyl (meth)acrylate, and aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate. It is preferable that the monomer unit contains an acrylic monomer having a relatively bulky structure, such as a (meth)acrylate having By imparting such a bulky structure to the (meth)acrylic oligomer, the adhesiveness of the resin layer can be further improved. In particular, in terms of bulkiness, those having a cyclic structure are highly effective, and those containing a plurality of rings are even more effective. In addition, when UV is used for the synthesis of (meth)acrylic oligomers or the preparation of resin layers, an ester of alcohol and (meth)acrylic acid that does not contain unsaturated bonds is used because it is less likely to cause polymerization inhibition. Certain (meth)acrylates are preferred. For example, an alkyl (meth)acrylate in which an alkyl group has a branched structure, or an ester of an alicyclic alcohol and (meth)acrylic acid can be suitably used as a monomer constituting the (meth)acrylic oligomer.

From this point of view, suitable (meth)acrylic oligomers include, for example, cyclohexyl methacrylate (CHMA), dicyclopentanyl acrylate (DCPA), dicyclopentanyl methacrylate (DCPMA), and isobornyl acrylate (IBXA). , isobornyl methacrylate (IBXMA) 1-adamantyl acrylate (ADA), 1-adamantyl methacrylate (ADMA) homopolymers; copolymers of CHMA and isobutyl methacrylate (IBMA), copolymers of CHMA and IBXMA Polymers, copolymers of CHMA and acryloylmorpholine (ACMO), copolymers of CHMA and diethylacrylamide (DEAA), copolymers of ADA and methyl methacrylate (MMA), copolymers of DCPMA and IBXMA , a copolymer of DCPMA and MMA; and the like. In particular, a (meth)acrylic oligomer containing CHMA as a main component is preferred.

When the (meth)acrylic oligomer is used in the resin composition disclosed herein, the amount used is not particularly limited. In some embodiments, the amount of the (meth)acrylic oligomer used is preferably 70 parts by weight or less, for example 1 to 70 parts by weight, more preferably 100 parts by weight of the (meth)acrylic polymer. is 2 to 50 parts by weight, more preferably 3 to 40 parts by weight. If the amount of the (meth)acrylic oligomer added is too large, the elastic modulus may become too high and the adhesion to rough surfaces at low temperatures may decrease. Further, by blending 1 part by weight or more of the (meth)acrylic oligomer with respect to 100 parts by weight of the (meth)acrylic polymer, the effect of improving the adhesive strength can be favorably exhibited. The technology disclosed herein can also be preferably practiced in a form that does not use a (meth)acrylic oligomer.

<Silane coupling agent>
The resin composition disclosed herein may contain a silane coupling agent for the purpose of improving adhesion reliability at the interface with the adherend. Silane coupling agents include, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3,4 epoxycyclohexyl)ethyl Epoxy group-containing silane coupling agents such as trimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N-(1,3 -Dimethylbutylidene)propylamine, amino group-containing silane coupling agents such as N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane and other (meth) ) acrylic group-containing silane coupling agents, isocyanate group-containing silane coupling agents such as 3-isocyanatopropyltriethoxysilane, and the like.

When the silane coupling agent is used, the amount used is preferably 1 part by weight or less, for example 0.01 to 1 part by weight, more preferably 0.02 to 0.6, per 100 parts by weight of the (meth)acrylic polymer. weight part. If the amount of the silane coupling agent used is too large, there is a possibility that cross-linking will be inhibited or adhesive properties will be impaired. The technology disclosed herein can also be preferably practiced without using a silane coupling agent.

In addition, the resin composition disclosed herein may optionally contain other known additives. For example, powders such as colorants and pigments, dyes, surfactants, plasticizers, surface lubricants, leveling agents, softeners, antioxidants, anti-aging agents, light stabilizers, ultraviolet absorbers, polymerization inhibitors, Inorganic or organic fillers, metal powders, particles, foils, and the like can be appropriately added depending on the application.

<Resin Layer and Laminated Sheet>
According to this specification, a resin layer formed from any one of the resin compositions disclosed herein is provided. The thickness of the resin layer is not particularly limited. The thickness of the resin layer may be, for example, about 1 μm to 1000 μm, preferably about 2 μm to 500 μm, more preferably 2 μm to 300 μm. From the viewpoint of improving adhesive strength and improving adhesion to rough surface irregularities, in some embodiments, the thickness of the resin layer may be, for example, 5 μm or more, 10 μm or more, 25 μm or more, or 35 μm or more. 50 μm or more, or 70 μm or more. Moreover, from the viewpoint of economy, in some embodiments, the thickness of the resin layer may be, for example, 200 μm or less, 150 μm or less, or 100 μm or less. Further, the resin layer disclosed herein may have a single layer structure or a multilayer structure of two or more layers.

The polymer gel fraction of the resin layer is not particularly limited. From the viewpoint of adhesion to rough surfaces, it is usually suitable to be 20 to 98% by weight. In some embodiments, the polymer gel fraction of the resin layer can be, for example, 20-95% by weight. When the polymer gel fraction of the resin layer is within the above range, high adhesive strength and high holding power tend to be favorably exhibited. It is presumed that this is because when the polymer gel fraction of the resin layer is within the above range, the softness of the resin layer can be maintained, and cohesive force can be imparted by forming an appropriate crosslinked network. .

From the viewpoint of further increasing the cohesive strength and holding power of the resin layer, the polymer gel fraction of the resin layer is, for example, preferably 22% by weight or more, more preferably 25% by weight or more, and 30% by weight or more. It is even more preferable to have In addition, from the viewpoint of improving rough surface adhesion at low temperatures, the polymer gel fraction of the resin layer is, for example, preferably 90% by weight or less, more preferably 85% by weight or less, and 80% by weight or less. is more preferably 75% by weight or less, and particularly preferably 70% by weight or less. In addition, when the resin composition contains a cross-linking agent, it is possible to control the gel fraction by adjusting the amount of the cross-linking agent added as a whole and considering the effects of the cross-linking treatment temperature and the cross-linking treatment time. can. The polymer gel fraction of the resin layer is measured by the method described in Examples below.

The resin layer disclosed herein preferably has a storage modulus G′ (23° C.) of 1.0×10 ⁴ Pa or more and 5.0×10 ⁴ Pa or less. When the storage elastic modulus G′ (23° C.) of the resin layer decreases, the adhesion of the resin layer to the unevenness of the rough surface (followability to the uneven shape) tends to increase. As the adhesion becomes higher, the contact area between the resin layer and the roughened surface becomes larger, and the adhesion becomes easier to improve. From this point of view, in some aspects, the resin layer preferably has a storage modulus G′ (23° C.) of, for example, 4.8×10 ⁴ Pa or less, and 4.6×10 ⁴ Pa or less. is more preferred. In addition, from the viewpoint of imparting an appropriate cohesive force to the resin layer to increase adhesive strength and holding power, the storage elastic modulus G′ (23° C.) of the resin layer may be, for example, 1.2×10 ⁴ Pa or more. , 1.5×10 ⁴ Pa or more.

The storage elastic modulus G' (23°C) of the resin layer can be measured using a commercially available dynamic viscoelasticity measuring device, and more specifically, it is measured by the method described in Examples below. The storage modulus G' (23°C) of the resin layer can be adjusted by the composition of the monomer components constituting the acrylic polymer, the use of a cross-linking agent, the use of a tackifying resin, and the like. For example, by increasing the weight fraction of monomer A2 in the monomer component, or by decreasing the weight ratio of monomer A1 to monomer A2 (that is, by using more monomer A2 to monomer A1) ), which can reduce the storage modulus G′ (23° C.) of the resin layer. An example of the monomer A2 highly effective in lowering the storage modulus G′ (23° C.) is a chain ether bond-containing (meth)acrylate represented by the above general formula (1), the homopolymer of which has a Tg of −40. °C or lower (more preferably -45°C or lower, more preferably -50°C or lower, for example -55°C or lower).

The resin layer disclosed herein preferably has a storage modulus G′ (−10° C.) of 3.0×10 ⁴ Pa or more and 7.0×10 ⁵ Pa or less. A low storage elastic modulus G′ (−10° C.) of the resin layer is advantageous from the viewpoint of making it easier for the resin layer to adhere well to the irregularities of the rough surface even at low temperatures, and increasing adhesion to the rough surface at low temperatures. is. From this point of view, in some aspects, the resin layer preferably has a storage modulus G′ (−10° C.) of, for example, 6.5×10 ⁵ Pa or less, and 6.0×10 ⁵ Pa or less. is more preferable. In addition, from the viewpoint of avoiding insufficient cohesion in the temperature range of room temperature or higher, the storage elastic modulus G′ (−10° C.) of the resin layer may be, for example, 5.0×10 ⁴ Pa or more, It may be 7.0×10 ⁴ Pa or more. The storage elastic modulus G′ (−10° C.) of the resin layer can be measured using a commercially available dynamic viscoelasticity measuring device, as with the storage elastic modulus G′ (23° C.), more specifically described later. It is measured by the method described in the working example. The storage modulus G' (-10°C) of the resin layer can be adjusted by adjusting the composition of the monomer components constituting the acrylic polymer, the use of a cross-linking agent, the use of a tackifying resin, and the like.

The haze value of the resin layer disclosed herein is not particularly limited. For example, when the thickness of the resin layer is 85 μm, the haze value of the resin layer can be 10% or less. In a preferred embodiment, the haze value of the resin layer with a thickness of 85 μm is 1.9% or less. Such a laminated sheet having a resin layer with high transparency is used in applications where high light transmittance is required in a structure with or without a support, and performance that allows good visibility of the adherend through the laminated sheet. is suitable for applications that require In addition, in a structure having a support, it is suitable for applications that require the property that the appearance of the support can be visually recognized well through the resin layer. The haze value of the resin layer with a thickness of 85 μm is more preferably 1.5% or less, still more preferably 1% or less, and still more preferably 0.7% or less. The lower limit of the haze value of the resin layer is not particularly limited. For example, the haze value of the resin layer at a thickness of 85 μm can be 0% or more (for example, 0.05% or more).

When the technology disclosed herein is implemented in the form of a laminated sheet with a substrate (support), the haze value of the laminated sheet is not particularly limited. For example, it can be implemented in a mode in which the haze value of the laminated sheet with a substrate is 15% or less. Such a highly transparent substrate-attached laminate sheet is suitable for applications that require high light transmittance and applications that require performance that enables good visibility of an adherend through the laminate sheet. In a preferred embodiment, the haze value of the laminated sheet with a substrate is 5% or less, more preferably 1.9% or less, still more preferably 1.5% or less (for example, 1% or less). The lower limit of the haze value of the laminated sheet with a substrate is not particularly limited. For example, the haze value of the laminated sheet with a substrate can be 0% or more (for example, 0.05% or more).

Here, the term "haze value" refers to the ratio of diffuse transmitted light to total transmitted light when an object to be measured is irradiated with visible light. Also called cloudiness value. A haze value can be represented by the following formula.
Th (%) = Td/Tt x 100
In the above formula, Th is the haze value (%), Td is the scattered light transmittance, and Tt is the total light transmittance. The haze value can be measured according to the method described in Examples below.

The resin layer can be formed as a laminated sheet by, for example, coating the resin composition on one or both sides of a support and removing the polymerization solvent and the like by heat drying or the like. The support constituting the laminated sheet may be a peelable support (that is, the resin layer constituting the laminated sheet can be peeled off) or a non-releasable support. Alternatively, a laminated sheet may be constructed by forming a resin layer from a resin composition coated on a releasable support and then laminating the resin layer on one side or both sides of a non-releasable support. In coating the resin composition, one or more solvents other than the polymerization solvent may be added as appropriate for the purpose of improving coatability and adjusting thickness.

Various methods can be used as a method for applying the resin composition. Specifically, for example, roll coating, kiss roll coating, gravure coating, reverse coating, roll brushing, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, die coater, etc. A method such as an extrusion coating method can be used.

The temperature for drying by heating is preferably 40 to 200°C, more preferably 50 to 180°C, and particularly preferably 70 to 170°C. By setting the heating temperature within the above range, a resin layer having excellent adhesive properties can be obtained. The heat drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 15 minutes, particularly preferably 10 seconds to 10 minutes.

In the embodiment in which the (meth)acrylic polymer is produced by polymerizing the monomer component by irradiating it with ultraviolet rays, the (meth)acrylic polymer can be produced from the monomer component and the resin layer can be formed. Materials that can be incorporated into the above resin composition, such as a cross-linking agent, can be appropriately incorporated into the monomer component. The above-mentioned monomer component can be used as a syrup by partially polymerizing it in advance before irradiating with ultraviolet rays. A high-pressure mercury lamp, a low-pressure mercury lamp, a metal halide lamp, or the like can be used for ultraviolet irradiation.

Examples of the support include polyolefin films mainly composed of polyolefins such as polyethylene (PE), polypropylene (PP), and ethylene-propylene copolymers, and polyesters mainly composed of polyethylene terephthalate (PET) and polybutylene terephthalate. Polyester film, polyvinyl chloride film mainly composed of polyvinyl chloride, polyethersulfone film, polystyrene film, polyacrylic film, polyurethane film, polyimide film, polyamide film, polyamideimide film, cycloolefin film, ethylene- Plastic films such as vinyl alcohol copolymer films; porous materials such as paper, cloth, and non-woven fabric; nets; foamed sheets such as polyethylene foams and acrylic foams; metal foils; Mention may be made of films. Examples of the composite include, but are not limited to, a laminate of metal foil and plastic film, and a plastic film reinforced with inorganic fibers such as glass fiber and carbon fiber. The concept of air bubbles in the air bubble-containing sheet includes air bubbles that do not have a solid outer shell and air bubbles that have a solid outer shell (for example, those containing hollow particles or the like). Therefore, in this application, the bubble-containing sheet is sometimes referred to as "a bubble- or particle-containing sheet". The air bubble or particle-containing sheet may include one or both of air bubbles without a solid shell and air cells with a solid shell.
The thickness of the support film is usually about 5 μm to 3000 μm, preferably about 10 μm to 2500 μm, more preferably about 20 μm to 2000 μm. In some embodiments, the thickness of the support film may be, for example, 1000 μm or less, 500 μm or less, 300 μm or less, 100 μm or less, or 50 μm or less.

If necessary, the support film may be subjected to mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, or the like. The support film may be subjected to antistatic treatment by coating, kneading, vapor deposition, or the like with an antistatic agent.

A structural example of a laminated sheet according to one embodiment is schematically shown in FIG. This laminated sheet 1 includes a support film 10 having a first surface 10A and a second surface 10B, and an adhesive layer 21 which is a resin layer provided on the first surface 10A side. The first surface 10A is non-releasable, whereby the laminate sheet 1 is configured as a single-sided pressure-sensitive adhesive sheet with a substrate. The laminated sheet 1 before use (that is, before being attached to an adherend) may further include a release liner 31 that protects the surface (adhesive surface) 21A of the adhesive layer 21, as shown in FIG. . The release liner 31 has a release surface (release surface) at least on the side in contact with the adhesive surface 21A. In practical use, the release liner 31 is peeled off from the adhesive surface 21A.

FIG. 2 schematically shows a structural example of a laminated sheet according to another embodiment. This laminated sheet 2 includes a support film 10 having a first surface 10A and a second surface 10B, an adhesive layer 21 which is a resin layer provided on the first surface 10A side, and a pressure-sensitive adhesive layer 21 provided on the second surface 10B side. and an adhesive layer 22 which is a resin layer. Both the first surface 10A and the second surface 10B are non-releasable, whereby the laminated sheet 2 is configured as a double-sided pressure-sensitive adhesive sheet with a substrate. The pressure-sensitive adhesive sheet 2 before use, as shown in FIG. may further include The release liners 31 and 32 have release surfaces at least on the sides that contact the adhesive surfaces 21A and 22A, and are peeled off from the adhesive surfaces 21A and 22A in practical use.

FIG. 3 schematically shows a structural example of a laminated sheet according to still another embodiment. This laminated sheet 3 includes an adhesive layer 21 that is a resin layer, a release liner 31 that protects one surface (first adhesive surface) 21A of the adhesive layer 21, and the other surface (second adhesive surface) 21A of the adhesive layer 21. and a release liner 32 that protects the adhesive surface 21B. In practical use, the release liners 31, 32 are peeled off from the adhesive surfaces 21A, 21B. The pressure-sensitive adhesive layer 21 of this embodiment can also be grasped as a pressure-sensitive adhesive sheet having no non-releasable support, that is, a substrate-less pressure-sensitive adhesive sheet.

Materials constituting the release liner include, for example, plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films; porous materials such as paper, cloth, and nonwoven fabric; nets; Suitable thin leaf bodies and the like can be exemplified. A plastic film can be preferably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the resin layer, and examples thereof include polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, vinyl chloride copolymer. Examples include coalesced films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate copolymer films and the like.

The thickness of the release liner is usually about 5 to 300 μm, preferably about 5 to 200 μm. If necessary, the release liner may be treated with a silicone, fluorine, long-chain alkyl or fatty acid amide release agent, silica powder, etc. for release and antifouling treatment, coating type, kneading type, vapor deposition type. An antistatic treatment can also be applied to the mold or the like. In particular, by subjecting the surface of the release liner to a release treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, the releasability from the resin layer can be further enhanced.

The resin layer disclosed herein (which may be a resin layer constituting a substrate-less pressure-sensitive adhesive sheet, a single-sided pressure-sensitive adhesive sheet with a substrate, or a double-sided pressure-sensitive adhesive sheet with a substrate; the same shall apply hereinafter) is a polypropylene (PP) plate. is preferably 10 N/20 mm or more, more preferably 11 N/20 mm or more. The adhesive strength of the resin layer to PP at room temperature may be, for example, 12 N/20 mm or more, or may be 13 N/20 mm or more. The upper limit of the room temperature adhesive strength to PP is not particularly limited, and may be, for example, about 30 N/20 mm or less.

The resin layer disclosed herein preferably has a room-temperature 180° peel adhesive strength (hereinafter also referred to as room-temperature adhesive strength to plywood) of 8 N/20 mm or more, measured using a softwood plywood as an adherend. The plywood room temperature adhesive strength is more preferably 10 N/20 mm or more, still more preferably 15 N/20 mm or more, and may be 18 N/20 mm or more or 20 N/20 mm or more. The upper limit of the adhesive strength to plywood at room temperature is not particularly limited, and may be, for example, about 50 N/20 mm or less, or about 40 N/20 mm or less.

The resin layer disclosed herein preferably has a room-temperature 180° peel adhesive strength (hereinafter also referred to as room-temperature adhesive strength to a calcium silicate plate) of 10 N/20 mm or more, measured using a calcium silicate plate as an adherend. . The room-temperature adhesive strength of the calcium silicate board is more preferably 15 N/20 mm or more, and may be 20 N/20 mm or more. The upper limit of the room-temperature adhesive strength to a silica glass plate is not particularly limited, and may be, for example, about 50 N/20 mm or less, or about 40 N/20 mm or less.

In the resin layer disclosed herein, the low-temperature 180° peel adhesive strength (hereinafter also referred to as low-temperature adhesive strength to plywood) measured with a softwood plywood as an adherend is, for example, 1 N/20 mm or more or 3 N/20 mm or more. It may be, and is preferably 5 N/20 mm or more. In some embodiments, the low-temperature adhesion to plywood may be, for example, 7 N/20 mm or more, or 9 N/20 mm or more. The (meth)acrylic polymer is a polymer of monomer components containing monomers A1 and A2 in specific proportions, and therefore has excellent flexibility even in a low temperature range. Therefore, even if a specific amount of tackifying resin is blended with the (meth)acrylic polymer, it is possible to exhibit good adhesion to rough surfaces such as softwood plywood in a low temperature range. Low temperature adhesion can be achieved favorably. The upper limit of the low-temperature adhesive strength to plywood is not particularly limited, and may be, for example, about 50 N/20 mm or less, or about 40 N/20 mm or less.

The room temperature 180° peel adhesive strength and the low temperature 180° peel adhesive strength of the resin layer are measured by the method described in Examples below. In the resin layer constituting the substrate-less pressure-sensitive adhesive layer (that is, the resin layer without a non-releasable support), in measuring the 180° peel adhesive strength, an appropriate backing material (for example, , a PET film having a thickness of about 25 μm) can be attached for reinforcement. The same applies to the holding force test described later. Also, the resin layer constituting the single-sided pressure-sensitive adhesive sheet with a substrate or the double-sided pressure-sensitive adhesive sheet with a substrate can be reinforced in the same manner, if necessary.

The resin layer disclosed herein preferably has a displacement distance of less than 1.0 mm, more preferably 0.8 mm or less, in a holding force test measured by the method described in Examples below. In such a laminated sheet, the resin layer has a moderately high cohesive force. With such a resin layer, the adherend can be firmly bonded or fixed.

<Application>
The resin layer disclosed herein can be preferably used for applications where it is attached to an adherend having a rough surface or plastic. Examples of the adherend having a rough surface include, but are not limited to, concrete, mortar, gypsum board, softwood plywood, woody cement board, calcium silicate board, tile, and fiber-reinforced cement board. The arithmetic mean roughness Ra of the rough surface can be, for example, about 1 μm to 800 μm. The laminated sheet can be preferably used particularly for an adherend having a rough surface with an arithmetic mean roughness Ra of 1 μm to 500 μm. The arithmetic mean roughness Ra of the rough surface may be, for example, about 3 μm to 300 μm, or about 5 μm to 150 μm. In addition, the resin layer and laminated sheet disclosed herein can be strongly adhered to smooth adherends, and can be preferably applied to such adherends.

The resin layer disclosed herein utilizes the feature that it can adhere well to both rough surfaces and plastics, and is used for applications where it is attached to both rough surfaces and plastics (for example, adherends with rough surfaces). It can be preferably used for joining plastic members). The plastic may be a low-polarity plastic such as polyolefin resin such as PP, PE.

Matters disclosed by this specification include the following.
[1] a (meth)acrylic polymer having a glass transition temperature of −40° C. or lower;
A tackifier resin of 5 parts by weight or more and 40 parts by weight or less with respect to 100 parts by weight of the (meth)acrylic polymer;
A resin composition containing
The (meth)acrylic polymer is
50 to 97% by weight of an alkyl (meth)acrylate (A1) having a homopolymer glass transition temperature of −50° C. or lower and having a branched alkyl group having 8 to 18 carbon atoms at the end of an ester group (A1), and
3 to 50% by weight of (meth)acrylate (A2) having a homopolymer glass transition temperature of −40° C. or less and having an ether bond in the molecular skeleton;
A resin composition that is a polymer of a monomer component containing
[2] The total proportion of the alkyl (meth)acrylate (A1) and the ether bond-containing (meth)acrylate (A2) is 75% by weight with respect to all monomer components forming the (meth)acrylic polymer. % or more, the resin composition according to the above [1].
[3] The ether bond-containing (meth)acrylate (A2) has the general formula (1):
_CH2 = ^CR1 -COO-(AO) _n - ^R2
(In the above general formula (1), R ¹ is a hydrogen atom or a methyl group, AO is an alkyleneoxy group having 2 to 3 carbon atoms, and n is a number indicating the average number of added moles of the alkyleneoxy group. is 1 to 10, and R ² is an aromatic ring or a linear, branched or alicyclic alkyl group);
The resin composition according to the above [1] or [2], which is a monomer represented by
[4] The resin composition according to [3] above, wherein AO in the general formula (1) is an oxyethylene group.
[5] The resin composition as described in [3] or [4] above, wherein n in the general formula (1) is 2 to 8.
[6] The resin composition according to any one of [3] to [5] above, wherein R ² in general formula (1) has 1 to 6 carbon atoms.
[7] The tackifying resin includes at least one selected from the group consisting of rosin-based tackifying resins, terpene-based tackifying resins, petroleum-based tackifying resins, and styrene-based tackifying resins. 6] The resin composition according to any one of the above items.
[8] The resin composition according to any one of [1] to [7] above, which contains, as the tackifying resin, at least one tackifying resin having a softening point of 90° C. or higher and 160° C. or lower.
[9] The above [1] to [8], wherein the monomer component contains at least one functional group-containing monomer selected from the group consisting of a monomer having a hydroxyl group, a monomer having a carboxyl group, and a monomer having an epoxy group. The resin composition according to any one of.
[10] The above [1] to [9], wherein the monomer component further contains a polyfunctional monomer in an amount of 5% by weight or less or 3% by weight or less with respect to the total monomer components forming the (meth)acrylic polymer. ] The resin composition according to any one of the above.
[11] The resin composition as described in any one of [1] to [10] above, wherein the (meth)acrylic polymer has a weight average molecular weight of 350,000 or more.
[12] The resin according to any one of [1] to [11] above, further containing 0.01 parts by weight or more and 5 parts by weight or less of a cross-linking agent with respect to 100 parts by weight of the (meth)acrylic polymer. Composition.
[13] The resin composition according to [12] above, wherein the cross-linking agent contains one or both of an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent.
[14] A resin layer formed from the resin composition according to any one of [1] to [13] above.
[15] The resin layer as described in [14] above, which has a storage modulus G' (23°C) of 1.0 x ¹⁰⁴ Pa or more and 5.0 x ¹⁰⁴ Pa or less.
[16] The resin layer according to [14] or [15] above, which has a storage modulus G' (-10°C) of 3.0 x ¹⁰⁴ Pa or more and 7.0 x ¹⁰⁵ Pa or less.
[17] The resin layer as described in any one of [14] to [16] above, which has a polymer gel fraction of 20% by weight or more and 98% by weight or less.
[18] The resin layer as described in any one of [14] to [16] above, which has a polymer gel fraction of 20% by weight or more and 95% by weight or less.
[19] The resin layer as described in any one of [14] to [18] above, wherein the resin layer has a haze value of 1.9% or less when the thickness is 85 μm.
[20] a support;
the resin layer according to any one of [14] to [19] provided on at least one side of the support;
A laminated sheet comprising:
[21] The laminated sheet of [20] above, wherein the resin layer has a 180° peel adhesive strength of 10 N/20 mm or more measured at a peel speed of 300 mm/min in an environment of 23°C.
[22] The laminate according to [20] or [21] above, wherein the resin layer has a 180° peel adhesive strength of 5 N/20 mm or more measured at a peel speed of 300 mm/min in an environment of -10°C. sheet.
[23] The laminated sheet according to any one of [20] to [22] above, wherein the support includes at least one of a plastic film, paper, nonwoven fabric, and a bubble- or particle-containing sheet.
[24] Used by being attached to an adherend having a rough surface, the adherend being selected from concrete, mortar, gypsum board, softwood plywood, woody cement board, calcium silicate board, tile and fiber-reinforced cement board. The laminated sheet according to any one of [20] to [23] above.
[25] The laminated sheet of [24] above, which is used for bonding an adherend having a rough surface and a plastic member.
[26] An adherend having a rough surface and the resin layer according to any one of [14] to [19] above, wherein the adherend and the above A laminated structure integrated with a resin layer.
[27] An adherend having a rough surface and the laminated sheet according to any one of [20] to [23] above, wherein the resin layer adheres to the rough surface to bond the adherend and the A laminated structure integrated with a laminated sheet.
[28] The adherend having a rough surface is selected from concrete, mortar, gypsum board, softwood plywood, wood cement board, calcium silicate board, tile and fiber reinforced cement board, above [26] or [ 27].

Several examples relating to the present invention will be described below, but the present invention is not intended to be limited to those shown in such specific examples. "Parts" and "%" in the following description are by weight unless otherwise specified.

Example 1
(Preparation of (meth)acrylic polymer)
90 parts of 2-ethylhexyl acrylate (2EHA), 10 parts of ethyl carbitol acrylate (CBA), 4-hydroxybutyl acrylate (4HBA) are placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas inlet tube, and a condenser. 0.25 parts, 1 part of acrylic acid (AA), 0.1 part of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator and 160 parts of ethyl acetate were charged together with gentle stirring. After introducing nitrogen gas and replacing with nitrogen for 1 hour, a polymerization reaction was carried out for 10 hours while maintaining the liquid temperature in the flask at about 60 to 65° C. to prepare a (meth)acrylic polymer solution. The (meth)acrylic polymer had an Mw of 850,000 as determined by GPC. The Tg calculated from the monomer composition of the (meth)acrylic polymer is -68.7°C.

Then, in the (meth)acrylic polymer solution obtained above, polymerized rosin ester (manufactured by Arakawa Chemical Industries, trade name: Pencel D125, softening point 120 to 130, ° C.) 20.0 parts, and 0.55 parts of a trimethylolpropane adduct of 2,4-tolylene diisocyanate (manufactured by Tosoh Corporation, trade name: Coronate L) as a cross-linking agent were blended to form a resin composition solution. prepared.

This resin composition solution was applied to the release surface of the release liner so that the thickness of the resin layer after drying was 85 μm, and dried at 130° C. for 3 minutes to form a resin layer. As a result, a laminated sheet having a resin layer on one side of the release liner (that is, a release support) was obtained. As the release liner, a PET film (Diafoil MRF, manufactured by Mitsubishi Plastics, Inc.) having a thickness of 38 μm and having a silicone-treated release surface on one side was used. The resin layer can also be understood as a substrate-less pressure-sensitive adhesive layer.

Examples 2-16 and Comparative Examples 1-3
In Example 1, the types and composition ratios of the monomers used in the preparation of the (meth)acrylic polymer, the types and amounts of the tackifying resins, and the types and amounts of the cross-linking agents are shown in Table 1. A laminated sheet was obtained by forming a resin layer having a thickness of 85 μm on the release surface of the release liner in the same manner as in Example 1 except for the above. Table 1 shows the Mw and Tg of the (meth)acrylic polymer according to each example.

The resin layers constituting the laminated sheets obtained in the above examples and comparative examples were evaluated as follows. Evaluation results are shown in Tables 1 and 2.

<Measurement of polymer gel fraction>
A predetermined amount (initial weight W1) of a sample is collected from the resin layer, immersed in an ethyl acetate solution and allowed to stand at room temperature for 1 week. , the gel fraction of the resin layer was calculated.
Resin layer gel fraction (%) = (W2/W1) x 100
From the obtained resin layer gel fraction, the polymer gel fraction was calculated by the following formula. The number of tackifying resin parts in the following formula means the number of parts of the tackifying resin contained in the resin layer with respect to 100 parts of the polymer contained in the resin layer.
Polymer gel fraction (%) = resin layer gel fraction (%) x (100 + number of tackifying resin parts)/100

<Measurement of storage modulus G'>
A laminate having a thickness of about 2 mm was produced by laminating the resin layers. A disk-shaped sample with a diameter of 7.9 mm was punched out of the laminate and sandwiched between parallel plates, and a temperature dispersion measurement was performed using a viscoelasticity tester under the following conditions. From the results, the storage elastic modulus G' (unit: Pa) at 23°C and -10°C was read.
[Test conditions]
Device: ARES manufactured by TA Instruments
Deformation mode: Torsion Measurement frequency: Constant frequency of 1 Hz (distortion: 0.1%)
Heating rate: 5°C/min Measurement temperature: Measurement from -70°C to 100°C Shape: Parallel plate with a diameter of 8.0 mm

<Room temperature adhesion measurement>
A PET film (Lumirror S10, manufactured by Toray Industries, Inc.) having a thickness of 25 μm was adhered to one side of the resin layer according to each example for backing, and a sample for evaluation was prepared. A test piece was prepared by cutting the evaluation sample into a width of 20 mm and a length of about 100 mm. Then, under a standard environment of 23 ° C. and 50% RH, the adhesive surface of the test piece (that is, the other surface of the resin layer) was attached to a softwood plywood (obtained from Shimachu Homes, thickness 12 mm) as an adherend. Calcium silicate plate (calcium plate, stained #400 manufactured by A&A Material Co., Ltd., thickness 6 mm) or polypropylene plate (cove poly sheet manufactured by Shin-Kobe Electric Machinery Co., Ltd., thickness 2 mm), 1 2 kg roller I pasted it back and forth. After allowing this to stand under the standard environment for 30 minutes, the peel adhesive strength (N/20 mm) was measured under the same environment under the conditions of a peel angle of 180° and a peel speed of 300 mm/min.

In addition, under a standard environment of 23 ° C. and 50% RH, the adhesive surface of the test piece (that is, the other surface of the resin layer) was attached to a glass plate (manufactured by Matsunami Glass Industry Co., Ltd., thickness 1 .2 mm) was pasted by reciprocating a 2 kg roller once. After allowing this to stand under the standard environment for 30 minutes, the peel adhesive strength (N/20 mm) was measured under the same environment under the conditions of a peel angle of 180° and a peel speed of 300 mm/min.

<Low temperature adhesion measurement>
A sample for evaluation prepared in the same manner as in the room temperature adhesive strength measurement was cut into a width of 20 mm and a length of about 100 mm to prepare a test piece. Next, after storing the adherend and the evaluation sample in an environment of -10 ° C. for 1 hour or more, under the same environment, the adhesive surface of the test piece is a softwood plywood as an adherend (obtained from Shimachu Homes, thickness 12 mm) was pasted by reciprocating a 2 kg roller once. After allowing this to stand in an environment of −10° C. for 30 minutes, the peel adhesive strength (N/20 mm) was measured under the same environment under the conditions of a peel angle of 180° and a peel speed of 300 mm/min.

<Holding force measurement>
A sample for evaluation prepared in the same manner as in the room temperature adhesive strength measurement was cut into a width of 10 mm and a length of about 100 mm to prepare a test piece. Then, the adhesive surface of the test piece was crimped to a bakelite plate (manufactured by Sumitomo Bakelite Co., Ltd., thickness 2 mm) as an adherend by reciprocating a 2 kg roller once over a bonding area of 10 mm in width and 20 mm in length. . The adherend to which the test piece was attached in this way was allowed to stand at room temperature (23 ° C.) for 30 minutes, and then hung so that the length direction of the test piece was in the vertical direction. A load of 500 g was applied to the free end, and the test piece was allowed to stand in an environment of 40° C. for 1 hour.

<Haze value measurement>
A resin layer according to each example was attached to one side of non-alkali glass having a total light transmittance of 93.3% and a haze value of 0.1% to obtain a test piece, and the haze value of the test piece was measured using a haze meter (MR-100 , Murakami Color Research Laboratory). In the measurement, the test piece was arranged so that the resin layer was on the light source side. Since the haze value of alkali-free glass is 0.1%, the haze value of the resin layer was obtained by subtracting 0.1% from the measured value.

The meaning of each abbreviation used in Table 1 is as follows.
2EHA: 2-ethylhexyl acrylate (manufactured by Toagosei Co., Ltd., homopolymer Tg = -70°C).
CBA: Ethyl carbitol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., homopolymer Tg = -67°C).
MTG: Methoxytriethylene glycol acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., homopolymer Tg = -57°C).
4HBA: 4-hydroxybutyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., homopolymer Tg = -32°C).
AA: acrylic acid (manufactured by Toagosei Co., Ltd., homopolymer Tg=106° C.).
BA: Butyl acrylate (manufactured by Toagosei Co., Ltd., homopolymer Tg = -55°C).
C: Trimethylolpropane/2,4-tolylene diisocyanate trimer adduct (manufactured by Tosoh Corporation, trade name: Coronate L).
DN: Trimethylolpropane adduct of xylylene diisocyanate (manufactured by Mitsui Chemicals, trade name: Takenate D110N)
D: Polymerized rosin ester having a softening point of 120 to 130°C (manufactured by Arakawa Chemical Industries, trade name: Pencel D125).
A: Rosin ester having a softening point of 95 to 105°C (manufactured by Arakawa Chemical Industries, trade name: Pencel AZ).
T: Terpene phenolic resin with a softening point of 125 to 135°C (manufactured by Yasuhara Chemical Co., Ltd., trade name: YS Polystar T130)
ND: not evaluated.

As shown in Table 2, the resin layers formed from the resin compositions of Examples 1 to 16 exhibited high room-temperature adhesive strength to both rough surfaces and plastics, and even at low temperatures showed good adhesion to These resin layers also had excellent holding power.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

1, 2, 3 laminated sheet 10 support film (support)
10A First surface 10B Second surface 21 Adhesive layer (resin layer)
21A adhesive surface (first adhesive surface)
21B adhesive surface (second adhesive surface)
22 Adhesive layer (resin layer)
22A adhesive surface (second adhesive surface)
31, 32 release liner

Claims (15)

a (meth)acrylic polymer having a glass transition temperature of −40° C. or lower;
5 parts by weight or more and 40 parts by weight or less of a tackifier resin with respect to 100 parts by weight of the (meth)acrylic polymer;
A resin composition containing
The (meth)acrylic polymer is
50 to 97% by weight of an alkyl (meth)acrylate (A1) having a homopolymer glass transition temperature of −50° C. or lower and having a branched alkyl group having 8 to 18 carbon atoms at the end of an ester group (A1), and
3 to 50% by weight of (meth)acrylate (A2) having a homopolymer glass transition temperature of −40° C. or less and having an ether bond in the molecular skeleton;
It is a polymer of a monomer component containing
The (meth)acrylate (A2) having an ether bond has the general formula (1):
CH2 =CR1 ^- COO-(AO _{) n} - ^R2
(In the general formula (1), R ¹ is a hydrogen atom or a methyl group, AO is an alkyleneoxy group having 2 to 3 carbon atoms, and n is a number indicating the average number of added moles of the alkyleneoxy group. is 1 to 10, and R ² is an aromatic ring or a linear, branched or alicyclic alkyl group.);
The resin composition , wherein the (meth)acrylic polymer has a weight average molecular weight of 500,000 or more . The total ratio of the alkyl (meth)acrylate (A1) and the (meth)acrylate (A2) having an ether bond is 75% by weight or more with respect to all monomer components forming the (meth)acrylic polymer. The resin composition of claim 1, wherein The resin according to claim 1 or 2 , wherein the tackifying resin comprises at least one selected from the group consisting of rosin-based tackifying resins, terpene-based tackifying resins, petroleum-based tackifying resins and styrene-based tackifying resins. Composition. The resin composition according to any one of claims 1 to 3 , comprising at least one tackifying resin having a softening point of 90°C or higher and 160°C or lower as the tackifying resin. 5. The monomer component according to any one of claims 1 to 4 , wherein the monomer component contains at least one functional group-containing monomer selected from the group consisting of a monomer having a hydroxyl group, a monomer having a carboxyl group, and a monomer having an epoxy group. The described resin composition. 6. The resin composition according to any one of claims 1 to 5, further comprising 0.01 parts by weight or more and 5 parts by weight or less of a cross-linking agent with respect to 100 parts by weight of the (meth)acrylic polymer. 7. The resin composition according to claim 6 , wherein the cross-linking agent includes one or both of an isocyanate-based cross-linking agent and an epoxy-based cross-linking agent. A resin layer formed from the resin composition according to claim 1 . Storage elastic modulus G′ at 23° C. is 1.0×10 ⁴ Pa or more and 5.0×10 ⁴ Pa or less, and
9. The resin layer according to claim 8 , wherein the storage elastic modulus G' at -10°C is 3.0 x ¹⁰⁴ Pa or more and 7.0 x ¹⁰⁵ Pa or less. 10. The resin layer according to claim 9 , wherein the polymer gel fraction is 20% by weight or more and 95% by weight or less. The resin layer according to any one of claims 8 to 10 , wherein the resin layer has a haze value of 1.9% or less when the thickness of the resin layer is 85 µm. a support;
a resin layer according to any one of claims 8 to 11 provided on at least one side of the support;
A laminated sheet comprising: 13. The laminated sheet according to claim 12 , wherein the resin layer has a 180[deg.] peel adhesive strength of 10 N/20 mm or more measured at a peel rate of 300 mm/min in an environment of 23[deg.]C. 14. The laminated sheet according to claim 12 , wherein the resin layer has a 180° peel adhesive strength of 5 N/20 mm or more measured at a peel rate of 300 mm/min in an environment of -10°C. 15. The laminated sheet according to any one of claims 12 to 14 , wherein the support comprises at least one of plastic film, paper, non-woven fabric and foam- or particle-containing sheet.

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