JP7340110B2 - Polyurethane-urea resin solutions and articles - Google Patents

Description

The present invention relates to polyurethane-urea resin solutions and articles using the same.

As adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, and the like are generally used. These pressure-sensitive adhesives are used, for example, in high value-added products such as packaging materials for foods and cosmetics, vehicles, wrapping films, protective films for smartphones, and medical tapes. In particular, products such as wrapping films and protective films are required to have excellent design properties, transparency, optical properties, and the like. However, acrylic resins, polystyrene resins, polycarbonate resins, and the like, which are used as base materials for these products, are all poor in chemical resistance.

In addition, light-shielding adhesive tape, etc., which is composed of an adhesive in which pigments, fillers, etc. are dispersed, is used to attach the liquid crystal display and the housing and to prevent light leakage from the light source inside the housing. has been proposed (Patent Document 1).

While acrylic pressure-sensitive adhesives have excellent adhesive strength, there are concerns about odors and the like due to residual monomers. In addition, due to its strong adhesive strength, it cannot be said that the removability after adhering to the adherend is so good, and there are problems such as difficulty in removability when used for products such as wrapping films and protective films. was there. In addition, silicone-based pressure-sensitive adhesives have a wide range of application temperatures and good weather resistance and chemical resistance. However, there is a concern that the adherend is likely to be contaminated, and that the low-molecular-weight silicone resin volatilizes and is likely to adhere to the surfaces of equipment such as electronic devices, causing problems in electrical systems. For this reason, it has been difficult to apply silicone pressure-sensitive adhesives to protective films for electronic components such as smartphones.

On the other hand, the urethane-based pressure-sensitive adhesive has the advantage of being slightly sticky, relatively excellent in removability, and containing components that are less likely to volatilize. However, urethane-based pressure-sensitive adhesives are slightly inferior in terms of adhesive strength, and therefore fall short of acrylic-based pressure-sensitive adhesives and silicone-based pressure-sensitive adhesives in terms of market size.

Prior art related to urethane-based pressure-sensitive adhesives includes, for example, a polyurethane/urea pressure-sensitive adhesive composition having a urethane group and a urea group, which exhibits sufficient adhesion even to non-polar films, and coating using the same has been proposed (Patent Document 2). In addition, a polyurethane adhesive composition that has good removability, etc., has good conformability to irregularities on adherends, and has low peel speed dependence of adhesive strength, and a pressure-sensitive adhesive sheet using the same etc. have been proposed (Patent Document 3). Furthermore, a pressure-sensitive adhesive composition has been proposed that has good initial pressure-sensitive adhesiveness, can be reapplied without adhesive residue, and can be used repeatedly to produce a strong-adhesive pressure-sensitive adhesive body in an arbitrary shape ( Patent document 4). A two-liquid curing composition using a polyurethane polyurea resin obtained by reacting a urethane prepolymer with an amine compound containing monoamine and diamine has also been proposed (Patent Document 5).

JP 2016-175967 A JP-A-2000-328034 JP 2006-182795 A JP 2009-167272 A WO2017/163900

However, when trying to produce an article such as an adhesive film using the adhesive compositions proposed in Patent Documents 3 and 4, it was necessary to use a separator such as a release film during winding. In addition, since the adhesive composition proposed in Patent Document 4 has strong adhesiveness, it cannot be said that re-peeling is so easy. Furthermore, the adhesive sheets produced using the adhesive compositions proposed in Patent Documents 2 to 4 cannot be said to have very good adhesion to the surface of the metal substrate (metal surface). There was room. In addition, when the composition proposed in Patent Document 5 is used as an adhesive or the like, there is a problem that adhesive residue tends to occur when re-peeling.

The present invention has been made in view of the problems of the prior art, and an object of the present invention is to provide a pressure-sensitive adhesive sheet or the like that has excellent adhesion to the surface of a metal or the like and can be rolled up without a separator. The object of the present invention is to provide a polyurethane-urea resin solution capable of easily producing a product of the above, and selectively increasing the peel strength by heating. Another object of the present invention is to provide articles such as paints, inks, coating agents, films and sheets obtained using the polyurethane-urea resin solution.

That is, according to the present invention, the following polyurethane-urea resin solution is provided.
[1] Polyurethane containing structural units derived from polyol component (A), structural units derived from diisocyanate component (B), and structural units derived from polyamine component (C), and having active amino groups at its terminals- It contains a urea resin, an optionally used polyfunctional polyisocyanate component (D), and a compound (E) having an epoxy group, and the terminal amino group concentration of the polyurethane-urea resin is 20 to 200 μEQ/g. and the polyurethane-urea resin is composed of the polyol component (A) having a reactive OH group and the diisocyanate component (B) having a reactive NCO group at a ratio of NCO/OH = 1.6 to 2.2 (mol/mol ) and the polyamine component (C) having a reactive amino group, (C)/(PP) = 1.05 to 1.5 ( mol/mol) of the reactant (excluding the reactant reacted with monoamine), and the content of the polyfunctional polyisocyanate component (D) is 100 parts by mass of the polyurethane-urea resin. is the amount represented by the following formula (1), and the content of the compound (E) having an epoxy group is represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin Polyurethane-urea resin solution in an amount to be used.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
=(X×N)/( _CNCO ×100) (1)
X: 0.0 to 65.0
C _NCO : NCO group content of polyfunctional polyisocyanate component (D) (%)
N: non-volatile content of polyurethane-urea resin (parts by mass)
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO x N/100 (2)
Y: 0.001 to 0.1
C _EPO : epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass)
[2] The polyurethane-urea resin solution according to [1] above, wherein the compound (E) having an epoxy group is an epoxy-modified silane coupling agent (E-1).
[3] The polyurethane-urea resin solution according to [1] or [2], which further contains a resin having a hydroxyl group in its side chain.
[4] The resin having a hydroxyl group in the side chain is at least one selected from the group consisting of hydroxyl-containing poly(meth)acrylate, polyvinyl alcohol, and polyhydroxyurethane, and the resin having a hydroxyl group in the side chain is contained. The polyurethane-urea resin solution according to [3], whose amount is 10 parts by mass or less with respect to 100 parts by mass of the polyurethane-urea resin.
[5] The polyurethane-urea resin solution according to any one of [1] to [4], wherein the polyol component (A) has a hydroxyl value of 30.0 to 200.0 mgKOH/g.
[6] The polyurethane-urea resin solution according to any one of [1] to [5], wherein the diisocyanate component (B) is at least one of an aliphatic diisocyanate and an alicyclic diisocyanate.
[7] The polyurethane-urea resin solution according to any one of [1] to [6], wherein the polyamine component (C) is a diamine that is liquid at room temperature.
[8] The polyurethane-urea resin solution according to any one of [1] to [7], wherein the polyurethane-urea resin has a weight average molecular weight of 5,000 to 150,000.
[9] The composition according to any one of [1] to [8], which further contains an organic solvent containing an alcohol solvent, and the content of the alcohol solvent in the organic solvent is 10 to 90% by mass. Polyurethane-urea resin solution.
[10] The above [1] to [8] further containing an organic solvent containing an ester solvent and an alcohol solvent, wherein the mass ratio of the ester solvent and the alcohol solvent is 50/50 to 10/90. Polyurethane-urea resin solution according to any one of
[11] The peel strength from the metal surface of the non-heated dry film is 1 to 200 mN / mm ² , and the peel strength from the metal surface of the heat-dried film formed by heating to 100 ° C. or higher is the same as the non-heated dry film. The polyurethane-urea resin solution according to any one of the above [1] to [10], which is ten times or more the peel strength from the metal surface of the polyurethane-urea resin solution, or at least part of which is broken when the peel strength is measured.

Further, according to the present invention, the following articles are provided.
[12] Any one of paints, inks, coating agents, hot-melt adhesives, films and sheets containing the polyurethane-urea resin solution according to any one of [1] to [11].

ADVANTAGE OF THE INVENTION According to the present invention, it is possible to easily produce a product such as a separator-less adhesive sheet that has excellent adhesion to the surface of a metal or the like and can be rolled up, and that the peel strength can be selectively increased by heating. It is possible to provide a polyurethane-urea resin solution that can also be used. Further, according to the present invention, articles such as paints, inks, coating agents, films and sheets obtained using the polyurethane-urea resin solution can be provided. The polyurethane-urea resin solution of the present invention can be developed for high-value-added and high-demand applications such as vehicle exterior materials.

<Polyurethane-urea resin solution>
Embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments. A polyurethane-urea resin solution, which is one embodiment of the present invention, contains a polyurethane-urea resin having an active amino group at its terminal and a compound (E) having an epoxy group. Further, the polyurethane-urea resin solution may further contain a polyfunctional polyisocyanate component (D) as an optional component. The polyurethane-urea resin has structural units derived from the polyol component (A), structural units derived from the diisocyanate component (B), and structural units derived from the polyamine component (C). The terminal amino group concentration of the polyurethane-urea resin is 20 to 200 μEQ/g. It is believed that a three-dimensional structure is formed by cross-linking at least a portion of the active amino groups (terminal amino groups) present at the ends of the polyurethane-urea resin, but the polyurethane-urea resin solution of the present embodiment does not form a coating. It is a possible composition and is useful as a paint, ink, coating agent, and the like. Details of the polyurethane-urea resin solution of the present embodiment will be described below.

(Polyol component (A))
Polyether polyols, polyester polyols, polycarbonate polyols, and the like can be used as the polyol component (A). Specific examples of the polyol component (A) include polyether polyols such as polypropylene glycol, polyethylene glycol, polytetramethylene glycol ether, polyoxytetramethylene polyoxyethylene glycol; polyethylene adipate, polybutylene adipate, polyhexamethylene adipate, poly Condensed polyester polyols such as 2-methyl-1,3-propanediol adipate, poly3-methyl-1,5-pentanediol adipate, and polyneopentyl glycol adipate; Lactone-based polyester polyols obtained by ring polymerization, such as polylactone diol, polycaprolactone diol, polymethylvalerolactone diol; polytetramethylene carbonate diol, polypentamethylene carbonate diol, polyneopentyl carbonate diol, polyhexamethylene carbonate diol , poly(1,4-cyclohexanedimethylene carbonate) diol, and polycarbonate polyols such as random/block copolymers thereof;

The polyol component (A) is preferably a propylene oxide-modified polyether polyol, and particularly preferably a polypropylene glycol containing a large amount of propylene oxide.
Such a polyol component (A) is particularly effective as a component that imparts tackiness because it is structurally excellent in flexibility and has collapsed crystallinity.

The hydroxyl value of the polyol component (A) is preferably 30.0 to 200.0 mgKOH/g, more preferably 35.0 to 160.0 mgKOH/g, and 50.0 to 115.0 mgKOH/g. is particularly preferred. If the hydroxyl value of the polyol component (A) is less than 30.0 mgKOH/g, it tends to be sticky. On the other hand, if the hydroxyl value exceeds 200.0 mgKOH/g, the tackiness tends to be insufficient.

(Diisocyanate component (B))
The diisocyanate component (B) is a compound having two isocyanate groups (NCO) in its molecular structure. Examples of the diisocyanate component (B) include aliphatic diisocyanates, alicyclic diisocyanates, and aromatic diisocyanates. However, the aromatic diisocyanate has high reactivity with the polyamine component (C), and it may be somewhat difficult to control the reaction. In addition, polyurethane-urea resins having aromatic groups may become less soluble in organic solvents and tend to gel. Furthermore, the diisocyanate component (B) is preferably at least one of an aliphatic diisocyanate and an alicyclic diisocyanate, since the tackiness may be slightly insufficient.

Examples of aliphatic diisocyanates include pentamethylene diisocyanate, hexamethylene diisocyanate, butane-1,4-diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, m- Tetramethylxylylene diisocyanate and the like can be mentioned. Alicyclic diisocyanates include isophorone diisocyanate, cyclohexane-1,4-diisocyanate, lysine diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, 4,4′ -dicyclohexylmethane diisocyanate, isopropylidene dicyclohexyl-4,4'-diisocyanate, norbornane diisocyanate and the like. These blocked isocyanates can also be used. Isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, hexamethylene diisocyanate, and pentamethylene diisocyanate are preferred from a comprehensive viewpoint of reactivity and physical properties.

Polyurethane-urea resins are typically reaction products of urethane prepolymers (PP) and polyamine components (C) having reactive amino groups. This urethane prepolymer (PP) is composed of a polyol component (A) having a reactive OH group and a diisocyanate component (B) having a reactive NCO group at an NCO/OH ratio of 1.6 to 2.2 (mol/mol). It is the reactants reacted in ratio. The ratio (NCO/OH) is the ratio of the amount (mol) of reactive NCO groups in the diisocyanate component (B) to the amount (mol) of reactive OH groups in the polyol component (A). be. If the value of the NCO/OH ratio is too small, the molecular weight of the urethane prepolymer (PP) and the polyurethane-urea resin will also increase, so the adhesive strength will become too strong and re-peeling may become difficult. be. From the viewpoint of reduction of residual monomers and productivity, it is preferable to set NCO/OH=1.8 to 2.0 (mol/mol).

(Polyamine component (C))
As the polyamine component (C), a liquid diamine or a solid diamine can be used at room temperature (25° C.). Among them, it is preferable to use a diamine that is liquid at room temperature (25°C). In order to form a polyurethane-urea resin having a diamine structure with active amino groups at its ends, a urethane prepolymer (PP) and diamine component (C) are generally reacted in excess of diamine component (C). When diamine, which is solid at room temperature, is allowed to react with urethane prepolymer (PP) at room temperature, the diamine dissolves as the reaction progresses, and the ratio of amino groups to isocyanate groups partially collapses, causing problems in the reaction. be. In addition, if diamine and urethane prepolymer (PP), which are solid at room temperature, are heated while reacting, the reaction speed becomes too fast and the reaction heat is generated, which may lead to an unexpected three-dimensional appearance. be. Therefore, it is preferable to use a diamine that is liquid at room temperature as the polyamine component (C).

The polyurethane-urea resin is composed of a urethane prepolymer (PP) and a polyamine component (C) having a reactive amino group at a ratio of (C)/(PP)=1.05 to 1.5 (mol/mol). is a reactant reacted with The ratio ((C)/(PP)) is the ratio of the amount (mol) of the polyamine component (C) to the amount (mol) of the urethane prepolymer (PP). However, the reactant (polyurethane-urea resin) does not include the reactant obtained by reacting not only the polyamine component (C) but also the monoamine with the urethane prepolymer (PP). When the urethane prepolymer (PP) is reacted not only with the polyamine component (C) but also with the monoamine, a polyurethane-urea resin having no active amino groups at both terminals is easily formed. Such a polyurethane-urea resin having no active amino groups at both ends does not have reaction points with the polyfunctional polyisocyanate component (D) or the epoxy group-containing compound (E). For this reason, when used as an adhesive or the like, adhesive residue is likely to occur upon re-peeling, and it becomes difficult to wind up a product such as an adhesive sheet without using a separator. Considering the adhesive strength due to heating, it is more preferable that (C)/(PP) = 1.05 to 1.25 (mol/mol), and (C)/(PP) = 1.10 to 1.25 (mol/mol). 20 (mol/mol) is particularly preferred.

Further, when the polyamine component (C) to be reacted with the urethane prepolymer (PP) contains a diamine having two amino groups in its molecular structure and a polyamine having three or more amino groups in its molecular structure, The molecular structure of the obtained reactant (polyurethane-urea resin) becomes easy to become three-dimensional. For this reason, when brought into contact with the polyfunctional polyisocyanate component (D) or the compound (E) having an epoxy group such as the epoxy-modified silane coupling agent (E-1), the viscosity may increase excessively and aggregation may occur. Things (so-called "butsu") may occur more easily. Therefore, it is preferable that the polyamine component (C) to be reacted with the urethane prepolymer (PP) is substantially only diamine.

As diamines that are liquid at room temperature, aliphatic diamines, alicyclic diamines, and aromatic diamines can be used. Such diamines include ethylenediamine, 1,5-pentanediamine, propylenediamine, trimethylhexamethylenediamine, isophoronediamine, 1,3-cyclohexyldiamine, dimerdiamine, polyetherdiamine, polyoxyalkylenediamine, poly(propylene glycol). ) diamines, hydrogenated products thereof, and the like. Among them, diamines having an alicyclic group such as isophoronediamine, 1,3-cyclohexyldiamine and dimer diamine are preferred.

As the diamine which is solid at room temperature, a diamine having a melting point of 35° C. or higher (preferably 50° C. or higher) can be used. Such diamines include 4,4'-diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 2,4 '-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, 2,3-tolylenediamine, 2,4-tri Aromatic diamines such as diamine, 2,5-tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine; 1,12-dodecanediamine, 1,10-decanediamine, 1,8- Aliphatic diamines such as octanediamine, 1,14-tetradecanediamine and 1,16-hexadecanediamine can be mentioned.

Since both ends of the polyurethane used in the pressure-sensitive adhesive composition described in Patent Document 3 are hydroxyl groups, aging is required when curing with isocyanate. On the other hand, in the case of the polyurethane-urea resin solution of the present embodiment, since a polyurethane-urea resin having a terminal amino group concentration of 20 to 200 μEQ/g is used, the polyfunctional polyisocyanate component (D) is contained as a curing agent. By doing so, aging can be made unnecessary. From the viewpoint of adhesiveness, it is more preferable that the terminal amino group concentration of the polyurethane-urea resin is 30 to 150 μEQ/g. In addition, the terminal amino group concentration of the polyurethane-urea resin is 100 to 150 μEQ/g in order to exhibit better metal adhesion due to the hydroxyl groups generated by the reaction with the epoxy groups of the compound (E) having an epoxy group. is particularly preferred. The "terminal amino group concentration" of the polyurethane-urea resin is a physical property value measured by potentiometric titration (neutralization titration) using 0.01 mol/L hydrochloric acid.

The weight average molecular weight (Mw) of the polyurethane-urea resin is preferably from 5,000 to 150,000. As described above, the polyurethane-urea resin is a reaction product obtained by reacting a urethane prepolymer with a polyamine component (C). If the weight-average molecular weight of the polyurethane-urea resin is less than 5,000, the polyamine component (C) may not react sufficiently, resulting in somewhat insufficient physical properties. On the other hand, if the weight-average molecular weight of the polyurethane-urea resin is more than 150,000, it tends to cause stringiness when used as a coating material, making it difficult to form a film. In order to further increase the adhesiveness, the weight average molecular weight of the polyurethane-urea resin is more preferably 10,000 to 150,000.

(Polyfunctional polyisocyanate component (D))
The polyurethane-urea resin solution of the present embodiment preferably further contains a polyfunctional polyisocyanate component (D). That is, the polyfunctional polyisocyanate component (D) is an optional component. Polyfunctional polyisocyanate component (D) is a component that can act as a curing agent. Therefore, by containing the polyfunctional polyisocyanate component (D), it is possible to obtain a polyurethane-urea resin solution that can produce products such as pressure-sensitive adhesive sheets without the need for curing by aging or heating.

Polyfunctional polyisocyanate component (D) is a polyisocyanate having more than two functional isocyanate groups. As the polyfunctional polyisocyanate component (D), diphenylmethane diisocyanate, toluene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate; these trimethylolpropane adducts, biuret modified, and nurate modified; polymeric MDI; isocyanate prepolymer; and the like. Polyisocyanates in the form of these blocks can also be used. Among them, hexamethylene diisocyanate-based or isophorone diisocyanate-based trimethylolpropane adducts, biuret modified products, and nurate modified products are preferable in terms of design and physical properties.

The polyfunctional polyisocyanate component (D) may react with, for example, an alcohol-based solvent in addition to the terminal amino groups of the polyurethane-urea resin. Furthermore, since the polyfunctional polyisocyanate component (D) may react with urethane bonds and urea bonds, the desired physical properties may not be obtained. Therefore, it is preferable to appropriately design the content of the polyfunctional polyisocyanate component (D) in the polyurethane-urea resin solution. Specifically, the content of the polyfunctional polyisocyanate component (D) is preferably an amount represented by the following formula (1) with respect to 100 parts by mass of the polyurethane-urea resin. That is, it is preferable to set the content of the polyfunctional polyisocyanate component (D) such that the value of X in the following formula (1) is from 0.0 to 65.0.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
=(X×N)/( _CNCO ×100) (1)
X: 0.0 to 65.0
C _NCO : NCO group content of polyfunctional polyisocyanate component (D) (%)
N: non-volatile content of polyurethane-urea resin (parts by mass)

Further, in order to improve adhesiveness by heat, it is preferable to set the content of the polyfunctional polyisocyanate component (D) such that the value of X in the above formula (1) is 0.0 to 50.0. . Furthermore, considering the balance of reaction with the compound (E) having an epoxy group, the polyfunctional polyisocyanate component (D) such that the value of X in the above formula (1) is 1.0 to 45.0 Content is preferred. Furthermore, in order to improve the initial adhesiveness, the content of the polyfunctional polyisocyanate component (D) may be such that the value of X in the above formula (1) is 5.0 to 30.0. preferable. If the value of X is more than 65.0, the reaction points with the compound (E) having an epoxy group, which will be described later, are reduced, so it may be difficult to improve the adhesion to the metal surface. Furthermore, when the value of X exceeds 80.0, the reaction of the excess polyfunctional polyisocyanate component (D) may not be completed, and the molecular structure becomes excessively three-dimensional, making coating difficult. Sometimes.

(Compound (E) having an epoxy group)
The polyurethane-urea resin solution of this embodiment contains the compound (E) having an epoxy group. The epoxy group-containing compound (E) reacts with the terminal amino group of the polyurethane-urea resin to generate a hydroxyl group (--OH group). For this reason, it is presumed that an article such as a pressure-sensitive adhesive sheet having excellent adhesion to a metal surface or the like can be obtained due to the generated hydroxyl groups.

Examples of the epoxy group-containing compound (E) include bisphenol A type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol F type epoxy resin, brominated bisphenol A type epoxy resin, phenol novolak type epoxy resin, and o-cresol novolak type epoxy resin. Epoxy resin, flexible epoxy resin, epoxidized polybutadiene, amine type epoxy resin, heterocyclic epoxy resin, alicyclic epoxy resin, bisphenol S type epoxy resin, dicyclopentadiene type epoxy resin, triglycidyl isocyanurate, bixylenol type epoxy resins, epoxy-modified silane coupling agents, and the like. Among them, using the epoxy-modified silane coupling agent (E-1) as the compound (E) having an epoxy group makes it possible to produce an article such as a pressure-sensitive adhesive sheet having particularly excellent adhesion to the glass surface. preferred.

The amount of the compound (E) having an epoxy group to be contained in the polyurethane-urea resin solution is determined in consideration of the competitive reaction with the polyfunctional polyisocyanate component (D), and from the viewpoint of improving adhesion to various substrates. need to be properly controlled. Specifically, the content of the epoxy group-containing compound (E) is preferably an amount represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin. That is, it is preferable to set the content of the compound (E) having an epoxy group such that the value of Y in the following formula (2) is from 0.001 to 0.1.
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO x N (2)
Y: 0.001 to 0.1
C _EPO : epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass)

In addition, from the viewpoint of further improving the adhesion to the metal surface, the content of the compound (E) having an epoxy group is such that the value of Y in the above formula (2) is 0.005 to 0.1. is preferred, and it is more preferred that the content of the compound (E) having an epoxy group is 0.005 to 0.05. If the value of Y is less than 0.001, it becomes difficult to improve the adhesion to the metal surface. On the other hand, when the value of Y is more than 0.1, the compound (E) having an unreacted epoxy group tends to remain, resulting in excessively high adhesiveness and difficulty in re-peeling.

(other ingredients)
The polyurethane-urea resin solution may contain other components, if desired. Other components include silane coupling agents (except for the above-mentioned "epoxy-modified silane coupling agent (E-1)") and the like. Among them, it is preferable to use a silane coupling agent having an isocyanate group or an acryloyl group because it can be reacted with the terminal amino group of the polyurethane-urea resin. The content of the silane coupling agent in the polyurethane-urea resin solution is preferably 1 part by mass or less with respect to 100 parts by mass of the polyurethane-urea resin, in order to improve adhesion to metal or glass. . If the content of the silane coupling agent exceeds 1 part by mass with respect to 100 parts by mass of the polyurethane-urea resin, the initial peel strength may become too high depending on the member.

The polyurethane-urea resin solution preferably further contains a resin having a hydroxyl group in its side chain. By containing a resin having a hydroxyl group in the side chain, it is possible to obtain a polyurethane-urea resin solution capable of producing an article such as a pressure-sensitive adhesive sheet with further improved adhesion to the base material to be coated. Examples of resins having hydroxyl groups in side chains include hydroxyl group-containing poly(meth)acrylates, polyvinyl alcohols, and polyhydroxyurethanes. Among these, polyhydroxyurethane is preferable because it is relatively compatible with the polyurethane-urea resin solution. In the polyurethane-urea resin solution, the content of the resin having a hydroxyl group in the side chain is preferably 10 parts by mass or less, preferably 7 parts by mass or less per 100 parts by mass of the polyurethane-urea resin, from the viewpoint of compatibility. It is more preferably 5 parts by mass or less, particularly preferably 1 part by mass or less, and most preferably 1 part by mass or less.

(Organic solvent)
The polyurethane-urea resin solution of this embodiment usually contains an organic solvent. That is, the polyurethane-urea resin is dissolved in an organic solvent. The polyurethane-urea resin solution preferably contains an organic solvent including an alcoholic solvent. Also, the content of the alcohol solvent in the organic solvent is preferably 10 to 90% by mass, more preferably 50 to 80% by mass, in order to easily adjust the coating viscosity. If the content of the alcohol-based solvent in the organic solvent is less than 10% by mass, the polyurethane-urea resin may become difficult to dissolve, making coating difficult at the stage of adding the polyfunctional polyisocyanate component (D). Sometimes. If the content of the alcohol-based solvent in the organic solvent exceeds 90% by mass, the reaction with the polyfunctional polyisocyanate component (D) is likely to occur, and the polyurethane-urea resin becomes difficult to dissolve, resulting in turbidity. .

Further, the polyurethane-urea resin solution preferably contains an organic solvent including an ester solvent and an alcohol solvent. The mass ratio of the ester solvent and the alcohol solvent in the organic solvent is preferably 50/50 to 10/90, more preferably 50/50 to 20/80. By containing organic solvents including ester-based solvents and alcohol-based solvents, even when coated on substrates with poor chemical resistance such as acrylic resins and polystyrene resins, these substrates do not whiten or dissolve. become difficult. If a ketone-based solvent or an amide-based solvent is used instead of an ester-based solvent, substrates having poor chemical resistance such as acrylic resins and polystyrene resins may whiten or dissolve. When an aliphatic hydrocarbon solvent is used, the polyurethane-urea resin may become difficult to dissolve, and may become turbid.

Examples of alcohol solvents include methyl alcohol, ethyl alcohol, isopropyl alcohol, n-butyl alcohol, tertiary butyl alcohol, etc.; ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, Examples include glycol ether ester solvents such as ethyl-3-ethoxypropionate. Among them, isopropyl alcohol is preferable as the alcohol-based solvent. Ester-based solvents include ethyl acetate, methyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, and isobutyl acetate. Among them, ethyl acetate is preferable as the ester solvent.

The organic solvent may contain organic solvents other than alcohol solvents and ester solvents. Other organic solvents include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; aromatic hydrocarbon solvents such as toluene and xylene; aliphatic hydrocarbon solvents such as n-hexane; dioxane, tetrahydrofuran and the like. amide solvents such as dimethylformamide and dimethylacetamide; lactam solvents such as N-methyl-2-pyrrolidone; and the like.

The peel strength from the metal surface of the unheated dry film formed by drying the polyurethane-urea resin solution of the present embodiment without heating is usually 1 to 200 mN/mm ² . The peel strength from the metal surface of the heat-dried film formed by heating the polyurethane-urea resin solution to 120° C. or higher is preferably at least 10 times the peel strength from the metal surface of the non-heated dry film. Alternatively, at least a portion of the material breaks (breaks without being able to be peeled off) when measuring the peel strength. That is, when the polyurethane-urea resin solution of the present embodiment is dried without heating, it can be wound up without a separator and has a slightly sticky property that can be peeled off again. By doing so, it is also possible to selectively increase the peel strength.

(Method for producing polyurethane-urea resin solution)
The polyurethane-urea resin solution of this embodiment can be produced by the following procedure. A polyol component (A) and a diisocyanate component (B) are reacted to obtain a urethane prepolymer having isocyanate groups at both ends. The resulting urethane prepolymer is subjected to a chain extension reaction in which the polyamine component (C) is reacted to obtain a polyurethane-urea resin having active amino groups at its terminals. The obtained polyurethane-urea resin, epoxy group-containing compound (E), and optionally used polyfunctional polyisocyanate component (D) are mixed. Further, if necessary, a silane coupling agent having a reactive group such as an isocyanate group and an acryloyl group may be added to obtain the desired polyurethane-urea resin solution. In addition, when manufacturing a urethane prepolymer, reaction catalysts, such as a metal catalyst and an amine salt, can be used as needed.

A catalyst may be used as necessary when producing the polyurethane-urea resin solution. Examples of catalysts include salts of metals such as dibutyltin laurate, dioctyltin laurate, stannus octoate, zinc octylate, and tetra-n-butyl titanate with organic or inorganic acids; organometallic derivatives; organic amines such as triethylamine; diazabicycloundecene-based catalysts; and the like.

It is also possible to adjust the physical properties of the polyurethane-urea resin solution and to impart durability by incorporating fillers and additives. As the filler, organic fillers and inorganic fillers can be used. More specifically, silica, fine particles of silicone resin, fine particles of fluorine resin, fine particles of acrylic resin, fine particles of urethane resin, fine particles of silicone-modified urethane resin, fine particles of polyethylene, fine particles of polycarbonate resin, and the like can be used as fillers. Examples of additives include antioxidants, light stabilizers, ultraviolet absorbers, gas discoloration stabilizers, metal deactivators, colorants, antifungal agents, flame retardants, matting agents, antifoaming agents, and lubricants. be able to.

<Goods>
An article that is one embodiment of the present invention is any of paints, inks, coating agents, hot-melt adhesives, films and sheets containing the polyurethane-urea resin solution described above. That is, the article of this embodiment contains the aforementioned polyurethane-urea resin solution. As described above, the polyurethane-urea resin solution of the present embodiment is an economical and environmentally friendly resin solution that can be wound up without a separator without curing or aging by heating during coating. . In addition, while exhibiting a slight adhesiveness to the extent that it can be reapplied in the initial stage, it is possible to selectively exhibit strong adhesiveness particularly to the surface of a metal substrate, etc., by heating. Furthermore, by selecting the organic solvent to be blended as necessary, the design and transparency are not impaired even when the coating is applied to a substrate having poor chemical resistance.

For this reason, the article of the present embodiment constituted by this polyurethane-urea resin solution is suitable as a paint, ink, coating agent, hot-melt adhesive, film, sheet, and the like. As for the film or sheet, the tackiness can be appropriately adjusted depending on the presence or absence of heating, and in particular, the film or sheet can be adhered more strongly to the metal substrate. Therefore, films and sheets are suitable as materials for high-value-added and high-demand applications such as electronic members, exterior applications, sanitary products, medical applications, and vehicle exterior materials. Hot-melt adhesives are also suitable as, for example, decorative films, wrapping films, apparel products, and adhesives and heat-sensitive adhesives for electronic members.

EXAMPLES The present invention will be specifically described below based on Examples, but the present invention is not limited to these Examples. "Parts" and "%" in Examples and Comparative Examples are based on mass unless otherwise specified.

<Materials used>
Various materials represented by the abbreviations shown in Tables 1 and 2 were prepared.

<Synthesis of urethane prepolymer>
(Synthesis example 1)
A reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blower, and manhole was provided. 100 parts of polyether polyol 1 (POL1) and 22.2 parts of isophorone diisocyanate (IPDI) were charged while purging the inside of the reaction vessel with nitrogen gas. A reaction was carried out at 100° C. for 5 hours under a nitrogen stream to obtain a urethane prepolymer (PP1) having an NCO group content of 3.437%. The obtained PP1 was dissolved in 40.7 parts of ethyl acetate (EtAc) to finally obtain a solution of PP1 having a non-volatile content of 75% and an NCO group content of 2.578%.

(Synthesis Examples 2-12)
A urethane prepolymer solution having a non-volatile content of 75% was obtained in the same manner as in Synthesis Example 1 described above, except that the types and amounts (unit: parts) of each component shown in the middle of Table 3 were used.

<Production of polyurethane-urea resin>
(Production example 1)
A diamine solution was obtained by mixing 9.9 parts of isophoronediamine (IPDA), 113.4 parts of EtAc, and 154.2 parts of isopropyl alcohol (IPA). 162.9 parts of the PP1 solution was added dropwise to the resulting diamine solution and allowed to react at 25° C. ^for 1 hour. It was confirmed. The reaction ratio ((C)/(PP)) between IPD A (polyamine component (C)) and PP1 (urethane prepolymer (PP)) was 1.17 (mol/mol). As a result, a solution of polyurethane-urea resin (PUA (A)) having a terminal amino group concentration (terminal amino group concentration per 1 g of resin solid content) of 128.6 μEQ/g (non-volatile content (solid content): 30% ). The terminal amino group concentration of the polyurethane-urea resin was measured by potentiometric titration (neutralization titration) using 0.01 mol/L hydrochloric acid using a sample prepared by dissolving the obtained resin in IPA.

(Production Examples 2 to 19)
A polyurethane-urea resin solution was obtained in the same manner as in Production Example 1 described above, except that the types and amounts (unit: part) of each component shown in the middle of Tables 4-1 and 4-2 were used. It should be noted that in Production Examples 11, 12, 14, 15, and 17, gelation did not occur.

<Preparation of polyurethane-urea resin solution (1)>
(Example 1)
A reaction vessel equipped with a stirrer, reflux condenser, thermometer, nitrogen blower, and manhole was provided. While replacing the interior of the reactor with nitrogen gas, 440.5 parts of a PUA (A) solution and 6.9 parts of a bisphenol A liquid epoxy resin (PEPO1), which is a compound having an epoxy group (Y = 0). .02763) was charged. EtAc and IPA were added to adjust the viscosity and non-volatile content to obtain a polyurethane-urea resin solution (PU1).

(Examples 2 to 21, Comparative Examples 1 to 10)
A polyurethane-urea resin solution was obtained in the same manner as in Example 1 above, except that the types and amounts (unit: parts) of each component shown in the middle of Tables 5-1, 5-2, and 6 were used. Ta.

<Production of adhesive film>
An A4 size OP film having a corona-treated coated surface was prepared. Each of the prepared polyurethane-urea resin solutions was coated on the coating surface of the OP film so that the dry film thickness was 5 μm. Immediately after drying at 80° C. for 2 minutes, an adhesive film was produced by winding the OP film on a 300 g iron bar with the back side (solution coated side facing out).

<Evaluation (1)>
(Windability without a separator)
The adhesive film wound around an iron rod without a separator was allowed to stand at room temperature (25°C) for one week, then lifted vertically to spread the adhesive film, and the winding property was evaluated according to the evaluation criteria shown below. . The same evaluation was also made after the adhesive film wound around an iron bar was left at 40° C. for one week. Results are shown in Tables 7 and 8.
A: It was possible to spread easily without using a separator.
○: It was possible to spread by applying force.
Δ: The coated surface was removed on the back side, or there was an adhesive residue on the back side.
x: Could not be spread, or peeling was difficult.

(Peel strength from metal surface)
The pressure-sensitive adhesive film evaluated for winding property (after 1 week at 25° C.) was attached to an iron plate of 75 mm×25 mm width to obtain a sample piece for peel strength measurement. Using a tensile tester (type name "Autograph AGS-100A", manufactured by Shimadzu Corporation), the peel strength (180° peel, tensile speed: 300 mm/min) of the adhesive film was measured. Results are shown in Tables 7 and 8.

(Thermal adhesion)
A heat-sealed sample was obtained by heating a sample piece for peel strength measurement prepared when measuring the above "peel strength" at 120° C. for 1 minute. Using a tensile tester, the peel strength (180° peel, tensile speed: 300 mm/min) of the adhesive film from the heat-sealable sample was measured, and the heat-sealability was evaluated according to the evaluation criteria shown below. Results are shown in Tables 7 and 8.
A: The adhesive film was broken.
◯: The adhesive film was partially broken.
Δ: Peeled off without breaking.
x: No change in peel strength.

(Effect on base material)
Each of the prepared polyurethane-urea resin solutions was coated on an A4 size transparent polystyrene film so that the dry film thickness was 5 μm. The film was observed immediately after drying at 80° C. for 2 minutes, and the influence on the substrate (film) was evaluated according to the evaluation criteria shown below. Results are shown in Tables 7 and 8.
A: No change was observed in film appearance.
◯: Slight change (turbidity) was observed in film appearance.
Δ: Clear change (whitening) was observed in film appearance.
x: An adhesive film could not be formed due to dissolution or the like.

<Evaluation (2)>
(Peel strength from glass surface)
Adhesive films produced using PU 5 and PU 18 to 21, respectively, were attached to glass plates of 75 mm×25 mm width to obtain sample pieces for peel strength measurement. Using a tensile tester, the peel strength of the adhesive film (180° peel, tensile speed: 300 mm/min) was measured. Table 9 shows the results.

(Thermal adhesion)
The sample pieces for peel strength measurement prepared when measuring the above "peel strength" were heated "at 100° C. for 1 minute" and "at 40° C. for 1 night" to obtain heat-sealed samples. Using a tensile tester, the peel strength (180° peel, tensile speed: 300 mm/min) of the adhesive film from the heat-sealable sample was measured, and the heat-sealability was evaluated according to the evaluation criteria shown below. Table 9 shows the results.
A: The adhesive film was broken.
◯: The adhesive film was partially broken.
Δ: Peeled off without breaking.
x: No change in peel strength.

<Preparation of polyurethane-urea resin solution (2)>
(Examples 22-24)
To 100 parts each of PU6, PU18, and PU19, HPU1, which is a resin having hydroxyl groups in side chains, was added to obtain polyurethane-urea resin solutions (PU6H, PU18H, and PU19H). Table 10 shows the formulation (unit: parts).

<Production of adhesive PET film>
An A4 size PET film having a corona-treated coated surface was prepared. Each of the prepared polyurethane-urea resin solutions was coated on the coating surface of the PET film so that the dry film thickness was 5 μm. Immediately after drying at 80° C. for 2 minutes, it was rolled up on a 300 g iron bar to produce an adhesive PET film.

<Evaluation (3)>
(Glass surface, peel strength with PET film)
The produced adhesive PET film was attached to a glass plate having a width of 75 mm×25 mm to obtain a sample piece for peel strength measurement. Using a tensile tester, the peel strength of the adhesive PET film (180° peel, tensile speed: 300 mm/min) was measured. Table 10 shows the results.

(Thermal adhesion)
The sample pieces for peel strength measurement prepared when measuring the above "peel strength" were heated "at 100° C. for 1 minute" and "at 40° C. for 1 night" to obtain heat-sealed samples. Using a tensile tester, the peel strength (180° peel, tensile speed: 300 mm/min) of the adhesive film from the heat-sealable sample was measured, and the heat-sealability was evaluated according to the evaluation criteria shown below. Table 10 shows the results.
A: The adhesive PET film was broken or partially broken.
○: The adhesive PET film did not break, but the peel strength was 10 times or more.
x: No change in peel strength.

The polyurethane-urea resin solution of the present invention is useful as a material constituting articles such as paints, inks, coating agents, hot-melt adhesives, films and sheets. Furthermore, the pressure-sensitive adhesive sheet produced using the polyurethane-urea resin solution of the present invention does not require a separator such as a release paper or a release film when wound, so it is extremely economical and ecological.

Claims (17)

A polyurethane-urea resin having a structural unit derived from the polyol component (A), a structural unit derived from the diisocyanate component (B), and a structural unit derived from the polyamine component (C), and having an active amino group at its end. ,
an optionally used polyfunctional polyisocyanate component (D);
and a compound (E) having an epoxy group,
The polyurethane-urea resin has a terminal amino group concentration of 20 to 200 μEQ/g,
The polyurethane-urea resin is composed of the polyol component (A) having a reactive OH group and the diisocyanate component (B) having a reactive NCO group at an NCO/OH ratio of 1.6 to 2.2 (mol/mol). Urethane prepolymer (PP), which is a reaction product reacted at a ratio, and the polyamine component (C) having a reactive amino group, (C)/(PP) = 1.05 to 1.5 (mol/ mol) of reactants (excluding reactants reacted with monoamines),
The content of the polyfunctional polyisocyanate component (D) is an amount represented by the following formula (1) with respect to 100 parts by mass of the polyurethane-urea resin,
A polyurethane-urea resin solution in which the content of the compound (E) having an epoxy group is represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
=(X×N)/( _CNCO ×100) (1)
X: 1.0 to 65.0
C _NCO : NCO group content of polyfunctional polyisocyanate component (D) (%)
N: non-volatile content of polyurethane-urea resin (parts by mass)
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO x N/100 (2)
Y: 0.001 to 0.1
C _EPO : epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass) A polyurethane-urea resin having a structural unit derived from the polyol component (A), a structural unit derived from the diisocyanate component (B), and a structural unit derived from the polyamine component (C), and having an active amino group at its end. ,
an optionally used polyfunctional polyisocyanate component (D);
and a compound (E) having an epoxy group,
The polyurethane-urea resin has a terminal amino group concentration of 100 to 150 μEQ/g,
The polyurethane-urea resin is composed of the polyol component (A) having a reactive OH group and the diisocyanate component (B) having a reactive NCO group at an NCO/OH ratio of 1.6 to 2.2 (mol/mol). Urethane prepolymer (PP), which is a reaction product reacted at a ratio, and the polyamine component (C) having a reactive amino group, (C)/(PP) = 1.05 to 1.5 (mol/ mol) of reactants (excluding reactants reacted with monoamines),
The content of the polyfunctional polyisocyanate component (D) is an amount represented by the following formula (1) with respect to 100 parts by mass of the polyurethane-urea resin,
A polyurethane-urea resin solution in which the content of the compound (E) having an epoxy group is represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
=(X×N)/(CNCO _× 100) (1)
X: 0.0 to 65.0
C _NCO : NCO group content of polyfunctional polyisocyanate component (D) (%)
N: non-volatile content of polyurethane-urea resin (parts by mass)
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO x N/100 (2)
Y: 0.001 to 0.1
C _EPO : epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass) A polyurethane-urea resin having a structural unit derived from the polyol component (A), a structural unit derived from the diisocyanate component (B), and a structural unit derived from the polyamine component (C), and having an active amino group at its end. ,
an optionally used polyfunctional polyisocyanate component (D);
and a compound (E) having an epoxy group,
The polyurethane-urea resin has a terminal amino group concentration of 20 to 200 μEQ/g,
The polyurethane-urea resin is composed of the polyol component (A) having a reactive OH group and the diisocyanate component (B) having a reactive NCO group at an NCO/OH ratio of 1.6 to 2.2 (mol/mol). Urethane prepolymer (PP), which is a reaction product reacted at a ratio, and the polyamine component (C) having a reactive amino group, (C)/(PP) = 1.05 to 1.5 (mol/ mol) of reactants (excluding reactants reacted with monoamines),
The content of the polyfunctional polyisocyanate component (D) is an amount represented by the following formula (1) with respect to 100 parts by mass of the polyurethane-urea resin,
The content of the epoxy group-containing compound (E) is an amount represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin.
Polyurethane-urea resin solution used for producing a separatorless, rollable pressure-sensitive adhesive sheet.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
= (X x N)/(C _NCOs × 100) (1)
X: 0.0 to 65.0
C. _NCOs : NCO group content (%) of polyfunctional polyisocyanate component (D)
N: non-volatile content of polyurethane-urea resin (parts by mass)
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO ×N÷100 (2)
Y: 0.001 to 0.1
C. _EPO : Epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass) 4. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the compound (E) having an epoxy group is an epoxy-modified silane coupling agent (E-1). 4. The polyurethane-urea resin solution according to any one of claims 1 to 3, further comprising a resin having a hydroxyl group in its side chain. The resin having a hydroxyl group in the side chain is at least one selected from the group consisting of hydroxyl-containing poly(meth)acrylate, polyvinyl alcohol, and polyhydroxyurethane,
6. The polyurethane-urea resin solution according to claim 5, wherein the content of the resin having a hydroxyl group in the side chain is 10 parts by mass or less with respect to 100 parts by mass of the polyurethane-urea resin. 4. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the polyol component (A) has a hydroxyl value of 30.0 to 200.0 mgKOH/g. 4. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the diisocyanate component (B) is at least one of an aliphatic diisocyanate and an alicyclic diisocyanate. 4. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the polyamine component (C) is a diamine that is liquid at room temperature. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the polyurethane-urea resin has a weight average molecular weight of 5,000 to 150,000. further containing an organic solvent including an alcohol-based solvent,
4. The polyurethane-urea resin solution according to any one of claims 1 to 3, wherein the content of said alcohol solvent in said organic solvent is 10 to 90% by mass. 12. The polyurethane-urea resin solution according to claim 11, wherein said alcoholic solvent is isopropyl alcohol. Further containing an organic solvent including an ester solvent and an alcohol solvent,
The polyurethane-urea resin solution according to any one of claims 1 to 3 , wherein the mass ratio of the ester solvent and the alcohol solvent is 50/50 to 10/90. 14. The polyurethane-urea resin solution according to claim 13, wherein the alcoholic solvent is isopropyl alcohol. The peel strength from the metal surface of the non-heated dry film is 1 to 200 mN / mm ² ,
The peel strength from the metal surface of the heat-dried film formed by heating to 100 ° C. or higher is 10 times or more the peel strength from the metal surface of the non-heated dry film, or at least a portion of the peel strength is measured. The polyurethane-urea resin solution according to any one of claims 1 to 3, which is broken. An article of any one of paints, inks, coating agents, hot-melt adhesives, films and sheets, comprising the polyurethane-urea resin solution according to any one of claims 1 to 3 . A method for producing a separator-less rollable pressure-sensitive adhesive sheet, comprising:
A polyurethane-urea resin having a structural unit derived from the polyol component (A), a structural unit derived from the diisocyanate component (B), and a structural unit derived from the polyamine component (C), and having an active amino group at its end. ,
an optionally used polyfunctional polyisocyanate component (D);
and a compound (E) having an epoxy group,
The polyurethane-urea resin has a terminal amino group concentration of 20 to 200 μEQ/g,
The polyurethane-urea resin is composed of the polyol component (A) having a reactive OH group and the diisocyanate component (B) having a reactive NCO group at an NCO/OH ratio of 1.6 to 2.2 (mol/mol). Urethane prepolymer (PP), which is a reaction product reacted at a ratio, and the polyamine component (C) having a reactive amino group, (C)/(PP) = 1.05 to 1.5 (mol/ mol) of reactants (excluding reactants reacted with monoamines),
The content of the polyfunctional polyisocyanate component (D) is an amount represented by the following formula (1) with respect to 100 parts by mass of the polyurethane-urea resin,
After drying the polyurethane-urea resin solution in which the content of the epoxy group-containing compound (E) is represented by the following formula (2) with respect to 100 parts by mass of the polyurethane-urea resin, a separator is formed. A method for producing a pressure-sensitive adhesive sheet, including winding with a less.
"Content (parts by mass) of polyfunctional polyisocyanate component (D)"
=(X×N)/(CNCO _× 100) (1)
X: 0.0 to 65.0
C _NCO : NCO group content of polyfunctional polyisocyanate component (D) (%)
N: non-volatile content of polyurethane-urea resin (parts by mass)
"Content (parts by mass) of compound (E) having an epoxy group"
= Y x C _EPO x N/100 (2)
Y: 0.001 to 0.1
C _EPO : epoxy equivalent weight (g/EQ) of the compound (E) having an epoxy group
N: non-volatile content of polyurethane-urea resin (parts by mass)