JP2023145348A - Aqueous composition for adhesives, adhesive and method for producing the same, patch, and adhesive tape - Google Patents

Abstract

To provide an aqueous composition for adhesives capable of producing an adhesive with excellent water solubility of solid content, high initial transparency, and a small change of haze, an adhesive including a cured product of the aqueous composition for adhesives and a production method therefor, a patch with an adhesive layer including the adhesive, and an adhesive tape with an adhesive layer including the adhesive.SOLUTION: An aqueous composition for adhesives includes a predetermined hydroxy group-terminated urethane prepolymer (X) resulting from the urethanation of a predetermined oxyalkylene polymer (A) with a diisocyanate compound (B), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z).SELECTED DRAWING: None

Description

The present invention relates to an aqueous composition for an adhesive, an adhesive and a method for producing the same, an adhesive material, and an adhesive tape.

Conventionally, flat panel displays (liquid crystal displays, organic electroluminescent displays, etc.), which are widely used in electronic devices such as televisions, personal computers (PCs), mobile phones, and mobile terminals, and flat panel displays and touch panels have been widely used. In touch panel displays that combine these, a surface protection film in which an adhesive layer is formed on a base material is widely used to protect these surfaces.
In general, adhesive compositions used to produce surface protection films may contain a polymer component such as an acrylic polymer or a prepolymer type (see, for example, Patent Document 1), and an organic solvent. Are known.
Organic solvents contained in such adhesive compositions may cause adverse effects on the environment such as carbon dioxide emissions when incinerated, odor, health problems, etc. There is a growing desire to reduce usage.

Japanese Patent Application Publication No. 2018-131500

Therefore, it has been considered to obtain a cured product by coating a water-based urethane prepolymer type adhesive composition for a surface protection film, drying, laminating, and heat curing. However, during the preparation and application of the aqueous composition for adhesives, the reaction between the urethane prepolymer and the curing agent progresses, and the cured product (adhesive) tends to become cloudy and have a high haze. There was a problem in that sufficient time was not available for preparing and coating the aqueous composition.

In view of the above problems, the present invention provides an aqueous composition for an adhesive that can produce an adhesive with excellent water solubility in solid content, high initial transparency, and small change in haze, and a method for curing the aqueous composition for an adhesive. An object of the present invention is to provide an adhesive obtained by the above-mentioned method, a method for producing the same, a patch having an adhesive layer containing the adhesive, and an adhesive tape having an adhesive layer containing the adhesive.

As a result of intensive studies to solve the above problems, the present inventors have found that a polyurethane prepolymer containing a predetermined hydroxyl group-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z) The inventors have discovered that the above problems can be solved by using an aqueous composition for adhesives, and have completed the present invention. This is because the hydroxyl-terminated urethane prepolymer (X) and the polyisocyanate compound (Y) do not react until the temperature at which the temperature-sensitive catalyst (Z) is activated (exothermic peak temperature) is reached, and the temperature-sensitive catalyst (Z) is activated. This is presumed to be based on the fact that the hydroxyl-terminated urethane prepolymer (X) and the polyisocyanate compound (Y) react only after the catalyst (Z) reaches the activation temperature (exothermic peak temperature).
That is, the present invention is as follows.
[1] Obtained by urethanizing an oxyalkylene polymer (A) having an oxyethylene group and having an average number of hydroxyl groups per molecule of 1.6 or more and 8.0 or less and a diisocyanate compound (B). An aqueous composition for an adhesive comprising a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z), wherein the oxyalkylene of the hydroxyl-terminated urethane prepolymer (X) An aqueous composition for an adhesive, wherein the content ratio of oxyethylene groups to the total amount of groups is 15% by mass or more and 90% by mass or less.
[2] The adhesive according to [1] above, wherein the temperature-sensitive catalyst (Z) is at least one selected from the group consisting of a piperazine-based amine catalyst, a morpholine-based amine catalyst, and a diazabicyclo compound-based catalyst. Aqueous composition.
[3] The aqueous composition for an adhesive according to [1] or [2] above, wherein the polyisocyanate compound (Y) is a water-dispersible polyisocyanate compound.
[4] The water-based adhesive composition according to [3] above, wherein the water-dispersible polyisocyanate compound is at least one selected from the group consisting of aliphatic polyisocyanates and alicyclic polyisocyanates.
[5] The hydroxyl group-terminated urethane prepolymer (X) is obtained by subjecting the oxyalkylene polymer (A) and the diisocyanate compound (B) to a urethanization reaction in the presence of a hydrolyzable catalyst (C). The aqueous composition for an adhesive according to any one of [1] to [4] above.
[6] The hydrolyzable catalyst (C) is a group consisting of Sn(II), Ca(II), Mn(II), Zn(II), Co(II), Pb(II) and Bi(III). The aqueous composition for an adhesive according to the above [5], which is a catalyst having at least one metal selected from the following.
[7] The aqueous composition for an adhesive according to any one of [1] to [6] above, wherein the hydroxyl group-terminated urethane prepolymer (X) has a weight average molecular weight of 15,000 or more and 100,000 or less.
[8] The aqueous composition for an adhesive according to any one of [1] to [7] above, wherein the oxyalkylene polymer (A) has a molecular weight in terms of hydroxyl value of 1,000 or more and 50,000 or less.
[9] The aqueous pressure-sensitive adhesive according to any one of [1] to [8] above, wherein the ratio of oxyethylene groups to the total amount of oxyalkylene groups in the oxyalkylene polymer (A) is 15% by mass or more. Composition.
[10] The oxyalkylene polymer (A) includes an oxyalkylene polymer (A1) having an average number of hydroxyl groups per molecule of more than 2.0 and 8.0 or less, and an oxyalkylene polymer (A1) having an average number of hydroxyl groups per molecule of 1. The aqueous composition for an adhesive according to any one of [1] to [9] above, comprising an oxyalkylene polymer (A2) having a molecular weight of 6 or more and 2.0 or less.
[11] The mass ratio of the oxyalkylene polymer (A1) to the oxyalkylene polymer (A2) is such that oxyalkylene polymer (A1)/oxyalkylene polymer (A2) is more than 0.0 and 4.0. The aqueous composition for an adhesive as described in [10] above, which is as follows.
[12] An adhesive obtained by curing the aqueous composition for an adhesive according to any one of [1] to [11] above.
[13] A patch comprising a base material and an adhesive layer provided on at least one surface of the base material and containing the adhesive described in [12] above.
[14] An adhesive tape comprising a base material and an adhesive layer containing the adhesive according to [12] above, provided on at least one surface of the base material.
[15] A method for producing a pressure-sensitive adhesive using the aqueous composition for pressure-sensitive adhesive according to any one of [1] to [11] above, comprising: the hydroxyl-terminated urethane prepolymer (X); , prepare an aqueous composition for an adhesive containing the polyisocyanate compound (Y) and the temperature-sensitive catalyst (Z), coat the aqueous composition for an adhesive on a base material, and apply the aqueous composition for an adhesive on a substrate. The base material coated with the aqueous composition for use is heated, the aqueous composition for adhesive is prepared at a temperature lower than the exothermic peak temperature of the temperature-sensitive catalyst (Z), and the heating is carried out at a temperature lower than the exothermic peak temperature of the temperature-sensitive catalyst (Z). A method for producing an adhesive, which is carried out at a temperature higher than the exothermic peak temperature of the chemical catalyst (Z).

According to the present invention, there is provided an aqueous composition for an adhesive that can produce an adhesive having excellent water solubility in solid content, high initial transparency, and small change in haze, and an aqueous composition for an adhesive that can be obtained by curing the aqueous composition for an adhesive. The present invention can provide an adhesive, a method for producing the same, a patch having an adhesive layer containing the adhesive, and an adhesive tape having an adhesive layer containing the adhesive.

The definitions and meanings of terms used in this specification are as follows.
In this specification, any of the preferable ones can be adopted, and combinations of the preferable ones can be said to be more preferable.
Furthermore, in this specification, the expression "XX to YY" means "XX to YY".
Moreover, in this specification, the lower limit and upper limit described in stages for preferred numerical ranges (for example, ranges of content, etc.) may be independently combined. For example, from the description "preferably 10 to 90, more preferably 30 to 60", the "preferable lower limit (10)" and "more preferable upper limit (60)" are combined to become "10 to 60". You can also do that. Further, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with the value shown in the Examples.
Furthermore, in this specification, the term "unit" constituting a polymer means an atomic group formed by polymerization of monomers.
Furthermore, in this specification, the term "oxyalkylene polymer" refers to a polymer having a polyoxyalkylene chain. Furthermore, a repeating unit based on alkylene oxide is referred to as an "alkylene oxide unit."
In addition, in this specification, "hydroxyl group-terminated urethane prepolymer (X)" refers to at least a portion of the terminal end of a molecular chain obtained by subjecting an oxyalkylene polymer (A) and a diisocyanate compound (B) to a urethanization reaction. A compound that has a hydroxyl group and a urethane bond in its molecular chain.
In addition, in this specification, for example, in the Examples described later, an oxyalkylene polymer is produced using a polyol (initiator A) obtained by adding propylene oxide to glycerin using a KOH catalyst until the molecular weight becomes 3,000 in terms of hydroxyl value. (A1-1) is being prepared, but in this case, the initiator for the oxyalkylene polymer (A1-1) is not "polyol (initiator A)" but glycerin, which is a starting material.
In addition, in this specification, when purchasing a mixture of oxyalkylene polymers, the type and molar ratio of the initiator of the oxyalkylene polymer can be specified using ^13C -NMR to determine the average hydroxyl group of the oxyalkylene polymer. Able to calculate numbers. On the other hand, when each oxyalkylene polymer is produced from an initiator, the number of hydroxyl groups in the initiator used itself becomes the average number of hydroxyl groups in the oxyalkylene polymer, and the number of hydroxyl groups in the oxyalkylene polymer is calculated from the number of hydroxyl groups in the initiator used. Able to recognize numbers.
Further, in this specification, "molecular weight in terms of hydroxyl value" is a molecular weight measured or calculated by the method described in Examples described later.
In addition, in this specification, "temperature-sensitive catalyst" refers to 100 parts by mass of polypropylene glycol having a molecular weight of about 2,000 in terms of hydroxyl value and 4,4'-diphenylmethane diisocyanate (MDI) with an isocyanate index of 105. In a mixed solution containing 1.16 parts by mass of catalyst, differential scanning calorimetry (DSC) under the following measurement conditions shows that the exothermic peak with a maximum heat flow of 1 mcal/s or more is at a temperature of 30 to 90°C. It refers to a catalyst observed in the range.
[DSC measurement conditions]
Measuring equipment: Seiko Instruments DSC-6100
Amount of mixed liquid to be measured: 10mg
Measurement temperature range: 0~200℃
Temperature increase/temperature decrease rate: 10° C./min Measurement atmosphere: Nitrogen In this specification, the term “hydrolyzable catalyst” refers to a catalyst that is deactivated after water is added.
Furthermore, in this specification, "solid content" means the components excluding the solvent, including the oxyalkylene polymer (A), the diisocyanate compound (B), the urethanization catalyst as an optional component, and the oxidation catalyst as an optional component. inhibitor, hydrolysis inhibitor as an optional component, ultraviolet rays as an optional component, light stabilizer as an absorber optional component, antistatic agent as an optional component, leveling agent as an optional component, alkylene oxide as an optional component, It means raw materials used in preparing the hydroxyl-terminated urethane prepolymer (X), such as polyol (initiator) as an optional component and diisocyanate as an optional component. In addition, from the weight change before and after drying the aqueous adhesive composition containing the above solid content in an oven at 40°C, the calculation formula is "solid content (%) = weight after drying / weight before drying x 100". The "solid content" can be calculated using

(Aqueous composition for adhesive)
The aqueous composition for an adhesive of the present invention contains a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z), preferably contains water, and further contains water. Contains other ingredients as required.

The solid content of the aqueous composition for adhesives of the present invention is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 18% by mass or more, particularly preferably 20% by mass or more, and Preferably it is 60% by mass or less, more preferably 56% by mass or less, even more preferably 52% by mass or less.
When the solid content is within the above range, the water dispersibility of the solid content tends to be better.

<Hydroxy group-terminated urethane prepolymer (X)>
The hydroxyl group-terminated urethane prepolymer (X) undergoes a urethanization reaction between the oxyalkylene polymer (A), the diisocyanate compound (B), and other polyols as optional components (polyols other than the oxyalkylene polymer (A)). This is what I did. A urethane bond is formed between the oxyalkylene polymer (A) and the diisocyanate compound (B) by the reaction between the hydroxyl group of the oxyalkylene polymer (A) and the isocyanate group of the diisocyanate compound (B). Among the hydroxyl groups possessed by the oxyalkylene polymer (A), the hydroxyl groups remaining unreacted with the isocyanate groups of the diisocyanate compound (B) become the terminal hydroxyl groups of the molecular chain of the urethane prepolymer.
The content of other polyols is not particularly limited as long as it does not inhibit the function of the hydroxyl-terminated urethane prepolymer (X) of the present invention, and is preferably 30% by mass or less based on the oxyalkylene polymer (A). More preferably, it is 10% by mass or less.

The content of the hydroxyl-terminated urethane prepolymer (X) in the aqueous composition for adhesives of the present invention is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 18% by mass or more, and , preferably 60% by mass or less, more preferably 56% by mass or less, still more preferably 52% by mass or less.
When the content is within the above range, the water dispersibility of the hydroxyl-terminated urethane prepolymer (X) tends to be better, and a cleaner coating film can be obtained during coating.

-Oxyalkylene polymer (A)-
The oxyalkylene polymer (A) (hereinafter also referred to as polymer (A)) is an oxyalkylene polymer having an oxyethylene group and having an average number of hydroxyl groups per molecule of 1.6 or more and 8.0 or less. be. Polymer (A) may include multiple oxyalkylene polymers.
The average number of hydroxyl groups per molecule of the polymer (A) is not particularly limited as long as it is 1.6 or more and 8.0 or less, but preferably 1.7 or more and 5.0 or less, more preferably 1.8. It is 4.0 or less, more preferably 1.9 or more and 3.0 or less.
When the average number of hydroxyl groups in the polymer (A) is within the above range, the adhesive force of the resulting pressure-sensitive adhesive to the base material can be within a suitable range.

The average number of hydroxyl groups per molecule of the polymer (A) can be calculated by specifying the type and molar ratio of the initiator using ¹³ C-NMR. In ¹³ C-NMR analysis, characteristic peaks of the initiator are observed, so the type and molar ratio of the initiator can be identified from the peak position and peak area.
Usually, the number of hydroxyl groups per molecule of the oxyalkylene polymer corresponds to the number of hydroxyl groups per molecule of the initiator used when synthesizing the oxyalkylene polymer. When an oxyalkylene polymer is synthesized using, for example, glycerin as an initiator, an oxyalkylene polymer having three hydroxyl groups per molecule is usually obtained. Further, when an oxyalkylene polymer is synthesized using, for example, pentaerythritol as an initiator, an oxyalkylene polymer having 4 hydroxyl groups per molecule is usually obtained. Further, when an oxyalkylene polymer is synthesized using, for example, dipropylene glycol as an initiator, an oxyalkylene polymer having two hydroxyl groups per molecule is usually obtained.
Further, the average number of hydroxyl groups per molecule of the polymer (A) can also be calculated from the number of hydroxyl groups per molecule based on the type of initiator and the mass fraction of the initiator. For example, when glycerin is 30% by mass and dipropylene glycol is 70% by mass, the average number of hydroxyl groups is 3×0.3+2×0.7=2.3.

The polymer (A) may include an oxyalkylene polymer (A1) described below and an oxyalkylene polymer (A2) described below.
The average number of hydroxyl groups per molecule of the oxyalkylene polymer (A1) is not particularly limited, but it is preferably more than 2.0, from the viewpoint of easily lowering the viscosity of the polymer (A) and making it easier to handle. .0 or less, more preferably 2.2 or more and 5.0 or less, still more preferably 2.4 or more and 4.0 or less, particularly preferably 2.6 or more and 3.0 or less.
The molecular weight in terms of hydroxyl value of the oxyalkylene polymer (A1) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, particularly preferably 8,000. or more, and is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, particularly preferably 15,000 or less. When the hydroxyl value equivalent molecular weight of the oxyalkylene polymer (A1) is within the above-mentioned preferred range, the resulting adhesive will have better flexibility.
There is no particular limit to the average number of hydroxyl groups per molecule of the oxyalkylene polymer (A2), but it tends to lower the viscosity of the polymer (A), making it easier to handle and improving the strength of the adhesive. From a simple standpoint, preferably 1.6 or more and 2.0 or less, more preferably 1.7 or more and 2.0 or less, even more preferably 1.8 or more and 2.0 or less, particularly preferably 1.9 or more and 2.0 or less. It is.
The molecular weight in terms of hydroxyl value of the oxyalkylene polymer (A2) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, particularly preferably 8,000. or more, and is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, particularly preferably 15,000 or less. When the hydroxyl value equivalent molecular weight of the oxyalkylene polymer (A2) is within the above-mentioned preferred range, the resulting adhesive will have better flexibility.
There is no particular restriction on the mass ratio of the oxyalkylene polymer (A1) and the oxyalkylene polymer (A2) (oxyalkylene polymer (A1)/oxyalkylene polymer (A2)), but the hydroxyl group-terminated urethane polymer From the viewpoint of suppressing gelation and high viscosity during production of polymer (X), preferably more than 0.0 (=0/100) and 4.0 (=80/20) or less, more preferably 0 It is more than 0.0 (=0/100) and less than 2.3 (=70/30), more preferably more than 0.0 (=0/100) and less than 1.5 (=60/40).

The alkylene oxide used when synthesizing the polymer (A) includes ethylene oxide (EO). The content ratio of oxyethylene groups (hereinafter also referred to as "EO unit content") with respect to the total amount of oxyalkylene groups in the polymer (A) is preferably 15% by mass or more. The alkylene oxide used when synthesizing the polymer (A) may be EO alone, but a combination of EO and an alkylene oxide having 3 to 5 carbon atoms is preferred, and a combination of EO and propylene oxide (PO) is preferable. is more preferable.
When two or more alkylene oxides are subjected to ring-opening addition, the arrangement of units derived from each alkylene oxide may be random, block, or tapered. Here, when the arrangement of the EO units and PO units is random, the polymer (A) may usually have a block body of PO units and a random body of EO units and PO units, and It may have a block body of EO units and a random body of EO units and PO units. Further, when the arrangement of EO units and PO units is a block, the polymer (A) may have a block of PO units, a block of EO units, and a block of PO units in this order. (The structure is "PO block - EO block - PO block"), and may have a block body in EO units, a block body in PO units, and a block body in EO units in this order (the structure is "PO block - EO block - PO block"). block - PO block - EO block" structure). Furthermore, when the arrangement of EO units and PO units is tapered, the oxyalkylene polymer (A) usually has a block body of PO units, a random body of EO units and PO units, and a block body of EO units. have
When EO and alkylene oxide other than EO are used together as alkylene oxide, the molar ratio of the content of EO units and alkylene oxide units other than EO units is the EO unit content relative to the total amount of oxyalkylene groups in the polymer (A). is selected so that it is 15% by mass or more. As the EO unit content increases, the hydrophilicity of the polymer (A) tends to improve, and as the EO unit content decreases, the crystallinity of the polymer (A) tends to decrease.
In addition, when the polymer (A) has an EO unit at the end, the end becomes a primary hydroxyl group, so the reactivity with the diisocyanate compound (B) tends to be higher than when the end is a PO unit. .

The content of EO units based on the total amount of oxyalkylene groups in the polymer (A) may be 100% by mass, but is preferably 15% by mass or more, more preferably 16% by mass or more, and even more preferably 18% by mass or more. , particularly preferably 20% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, particularly preferably 60% by mass or less, and most preferably 50% by mass. It is as follows.
When the content of EO units based on the total amount of oxyalkylene groups in the polymer (A) is within the above-mentioned preferred range, the polymer (A) tends to become amorphous, making it easier to handle, and the resulting hydroxyl-terminated urethane prepolymer is less soluble in water. properties are better.
The reaction system for obtaining the hydroxyl group-terminated urethane prepolymer (X) may contain an oxyalkylene polymer (A0) in which the content of EO units is less than 15% by mass with respect to the total amount of oxyalkylene groups. When the oxyalkylene polymer (A0) is included, the content of the oxyalkylene polymer (A0) relative to the mass of the polymer (A) is preferably 40% by mass or less.

The EO unit content relative to the total amount of oxyalkylene groups in the polymer (A) was calculated by determining the monomer unit composition of the oxyalkylene chain using ¹³ C-NMR. For example, when the polymer (A) is a polyol consisting of PO units and EO units, the EO unit content is determined from the area ratio of the methyl group signal in the PO unit and the methylene group signal in the PO unit and EO unit. can be found.

The molecular weight in terms of hydroxyl value of the polymer (A) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, particularly preferably 6,000 or more. It is also preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, particularly preferably 15,000 or less. When the molecular weight in terms of hydroxyl value of the polymer (A) is within the above-mentioned preferred range, the resulting adhesive will have better flexibility.
When two or more types of polymers (A) are included, it is preferable that the number average molecular weight of each polymer (A) is within the above-mentioned preferred range.

The number average molecular weight (Mn) of the polymer (A) is not particularly limited, but is preferably 1,000 or more, more preferably 3,000 or more, even more preferably 5,000 or more, particularly preferably 7,000 or more. It is also preferably 50,000 or less, more preferably 30,000 or less, even more preferably 20,000 or less, particularly preferably 15,000 or less. When the Mn of the polymer (A) is within the above preferred range, the resulting adhesive will have better flexibility.
When two or more types of polymers (A) are included, it is preferable that Mn of each polymer (A) is within the above-mentioned preferred range.

The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight (Mw/Mn)) of the polymer (A) is not particularly limited, but is preferably less than 1.40, more preferably less than 1.20. be. By setting the Mw/Mn of the polymer (A) to less than 1.20, the reactivity tends to be good, the hydroxyl-terminated urethane prepolymer (X) can be produced more efficiently, and the obtained hydroxyl-terminated urethane prepolymer ( The viscosity of X) is more likely to decrease.
When two or more types of polymers (A) are included, it is preferable that the Mw/Mn of each polymer (A) is within the above-mentioned preferred range.

Mn and Mw/Mn of the polymer (A) are values obtained by measurement by the method described below.
As a standard sample for molecular weight measurement, several types of monodispersed polystyrene with different degrees of polymerization were measured using a commercially available GPC measurement device (HLC-8320GPC, manufactured by Tosoh Corporation), and the relationship between the molecular weight of polystyrene and retention time was determined. A calibration curve was created, and the measurement sample, polymer (A), was diluted to 0.5% by mass with tetrahydrofuran and passed through a filter with a pore size of 0.5 μm. Measure using Mn and Mw of the measurement sample are determined by computer analysis of the GPC spectrum of the measurement sample using the above calibration curve.
The molecular weight distribution (Mw/Mn) is a value calculated from the above Mw and Mn.

The degree of unsaturation of the polymer (A) is not particularly limited, but is preferably 0.015 meq/g or less, more preferably 0.014 meq/g or less, even more preferably 0.013 meq/g or less. The degree of unsaturation of the polymer (A) may be zero. If the degree of unsaturation of the polymer (A) is below the above upper limit, the curability of the resulting hydroxyl group-terminated urethane prepolymer (X) will be better.
The degree of unsaturation of the polymer (A) is a value measured according to the method of JIS K 1557-3:2007.

The hydroxyl value of the polymer (A) is not particularly limited, but is preferably 2 mgKOH/g or more, more preferably 5 mgKOH/g or more, even more preferably 8 mgKOH/g or more, and preferably 50 mgKOH/g or less, More preferably it is 45 mgKOH/g or less, still more preferably 40 mgKOH/g or less. If the hydroxyl value of the polymer (A) is below the above upper limit, the resulting adhesive will have better flexibility.
The hydroxyl value of the polymer (A) is a value measured and calculated according to method B of JIS K 1557-1:2007.

As one aspect of the present invention, the polymer (A) is an oxyalkylene polymer a (hereinafter referred to as "polymer a") having 3 hydroxyl groups per molecule and 2 polymers having 2 hydroxyl groups per molecule. It may be made of a certain oxyalkylene polymer b (hereinafter referred to as "polymer b"). When the polymer (A) contains polymer a and polymer b, the viscosity of the polymer (A) tends to be low, making it easier to handle, and also making it easier to adjust the adhesive force to the base material to a more appropriate range.

The mass ratio of polymer a in polymer (A) is not particularly limited and may be 0 mass%, but preferably 10 to 90 mass%, more preferably 20 to 80 mass%, and even more preferably It is 30 to 70% by mass.

The mass proportion of polymer a contained in polymer (A) can be determined by, for example, identifying the type of initiator contained in polymer (A) and its molar ratio using ¹³ C-NMR, and determining its peak area. It can be calculated as the ratio of

In order to synthesize polymer a, an initiator having three hydroxyl groups in one molecule is used. Glycerin is preferred as an initiator for synthesizing polymer a. Glycerin is available at low cost and can reduce the cost of synthesizing polymer a.

The alkylene oxide used in the synthesis of polymer a is the same as the alkylene oxide used in synthesizing the polymer (A) described above.
When water is contained in the raw materials used to synthesize the polymer (A), the alkylene oxide is addition-polymerized using water as an initiator to form a polymer having two hydroxyl groups per molecule (polymer b). ) may be produced as a by-product. The by-product may be contained in the polymer (A) as long as the average number of hydroxyl groups in the resulting polymer (A) is 1.6 or more and 8.0 or less.

The mass ratio of polymer b in polymer (A) is not particularly limited and may be 100% by mass, but is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass. % or more.

The mass ratio of polymer b contained in polymer (A) can be calculated in the same manner as when calculating the mass ratio of polymer a contained in polymer (A) described above.

In order to synthesize polymer b, water or an initiator having two hydroxyl groups in one molecule is used. The initiator having two hydroxyl groups in one molecule for synthesizing polymer b is preferably one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; One or more types selected from dipropylene glycol are more preferred, and propylene glycol is particularly preferred. Propylene glycol is available at low cost and can reduce the cost of synthesizing polymer b.

The alkylene oxide used in the synthesis of the polymer b is the same as the alkylene oxide used in synthesizing the polymer (A) described above, and the preferred embodiments are also the same.

The polymer (A) may contain oxyalkylene polymers other than the above polymers a and b. Oxyalkylene polymers other than polymer a and polymer b include oxyalkylene polymer c having a number of hydroxyl groups per molecule of 4 or more (hereinafter referred to as "polymer c"), and oxyalkylene polymer c having a number of hydroxyl groups per molecule of 4 or more (hereinafter referred to as "polymer c"). Oxyalkylene polymer d (hereinafter referred to as "polymer d"), which is No. 1, can be mentioned.

In order to synthesize polymer c, an initiator having four or more hydroxyl groups in one molecule is used. Examples of initiators having four or more hydroxyl groups in one molecule include polyhydric alcohols of four or more valences such as diglycerin, pentaerythritol, dipentaerythritol, and tripentaerythritol, as well as glucose, sorbitol, dextrose, fructose, and sucrose. and saccharides such as methyl glucoside or derivatives thereof.

In order to synthesize the polymer d, an initiator having one hydroxyl group in one molecule is used. As the initiator having one hydroxyl group in one molecule, monohydric alcohols having 2 to 4 carbon atoms are preferred because they are available at low cost, and propanol (n-propyl alcohol), 2-propanol ( isopropanol), 1-butanol (n-butyl alcohol), 2-butanol (sec-butyl alcohol), 2-methyl-1-propanol (isobutyl alcohol), and 2-methyl-2-propanol (tert-butyl alcohol). More preferred are 1-butanol (n-butyl alcohol), 2-butanol (sec-butyl alcohol), 2-methyl-1-propanol (isobutyl alcohol), and 2-methyl-2-propanol (tert-butyl alcohol). preferable.

The alkylene oxide used in the synthesis of the polymer c or the polymer d is the same as the alkylene oxide used in synthesizing the polymer (A) described above, and the preferred embodiments are also the same.

The ratio of the total mass of polymer c and polymer d to the total mass of polymer a and polymer b in the polymer (A) is preferably 20% by mass or less, more preferably 10% by mass or less, and It is preferably 3% by mass or less, and may not be included.

As a catalyst for ring-opening addition polymerization of an alkylene oxide to an initiator, a conventionally known catalyst can be used. For example, an alkali catalyst such as KOH, a transition metal compound-porphyrin complex catalyst such as a complex obtained by reacting an organoaluminum compound and a porphyrin, a multimetal cyanide complex catalyst (DMC catalyst), and a catalyst consisting of a phosphazene compound are used. Can be mentioned. The amount of catalyst to be used can be a conventionally known amount. For example, when using a DMC catalyst, the amount used is preferably such that the metal concentration of the DMC catalyst in the reaction solution is 1 to 500 ppm by mass.
When obtaining the oxyalkylene polymer (A) using a DMC catalyst, it is preferable because the Mw/Mn of the obtained oxyalkylene polymer (A) can be narrowed and an oxyalkylene polymer (A) with low viscosity can be easily obtained. .
A conventionally known compound can be used as the DMC catalyst, and a known method can also be adopted as a method for producing a polymer using a DMC catalyst. For example, WO 2003/062301, WO 2004/067633, JP 2004-269776, JP 2005-015786, WO 2013/065802, JP 2015-010162 The compounds and manufacturing methods disclosed in, et al. can be used.
A conventionally known method can be employed to obtain the polymer (A) by ring-opening addition polymerization of alkylene oxide to an initiator. For example, manufacturing methods disclosed in International Publication No. 2011/125951, Japanese Patent No. 5648797, etc. can be used.

-Diisocyanate compound (B)-
The diisocyanate compound (B) used to react with the above polymer (A) to obtain the hydroxyl group-terminated urethane prepolymer (X) is particularly suitable as long as it is an organic compound having two isocyanate groups in one molecule. There is no limitation, and examples thereof include aliphatic diisocyanate compounds, alicyclic diisocyanate compounds, aromatic diisocyanate compounds, and araliphatic diisocyanate compounds.

Examples of aliphatic diisocyanate compounds include linear aliphatic diisocyanates such as tetramethylene diisocyanate, dodecamethylene diisocyanate, and hexamethylene diisocyanate (HDI); 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexocyanate Branched aliphatic diisocyanates such as methylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate; The aliphatic diisocyanate compounds may be used alone or in combination of two or more.
Among these, straight-chain aliphatic diisocyanates are preferable because they are less prone to discoloration (yellowing) of the adhesive and have better physical properties such as tensile strength and elongation at break. Linear aliphatic diisocyanates of No. 8 are more preferred, and hexamethylene diisocyanate (HDI) is particularly preferred. Physical properties such as tensile strength and elongation at break are assumed to be due to the good symmetry of the molecular structure of these isocyanate compounds.

Examples of the alicyclic diisocyanate compound include isophorone diisocyanate (IPDI), hydrogenated xylylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, and 1,3-bis(isocyanate). Methyl) cyclohexane and the like. The alicyclic diisocyanate compounds may be used alone or in combination of two or more.
Among these, isophorone diisocyanate (IPDI) and 4,4'-dicyclohexylmethane diisocyanate are preferred, and isophorone diisocyanate (IPDI) is preferred because the adhesive is less prone to discoloration (yellowing) and isocyanate compounds are easily available. More preferred.

Examples of aromatic diisocyanate compounds include tolylene diisocyanate (TDI), 2,2'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), and 4,4'-dibenzyl. Examples include diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, and 1,4-phenylene diisocyanate. The aromatic diisocyanate compounds may be used alone or in combination of two or more.
Among these, diphenylmethane diisocyanate is preferred because it has good reactivity and good symmetry of the molecular structure of the isocyanate compound, resulting in better physical properties such as tensile strength and elongation at break of the adhesive. , 4,4'-diphenylmethane diisocyanate (MDI) is more preferred.

Examples of the aromatic aliphatic diisocyanate compound include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α,α,α',α'-tetramethylxylylene diisocyanate, and the like. The aromatic aliphatic diisocyanate compounds may be used alone or in combination of two or more.
Among these, α, α, α', α'-tetra is used because the isocyanate compound has good molecular structure symmetry, and the adhesive has better physical properties such as tensile strength and elongation at break. Methyl xylylene diisocyanate is preferred.

The diisocyanate compound (B) used in the production of the hydroxyl-terminated urethane prepolymer (X) is difficult to cause discoloration (yellowing) of the adhesive and has good molecular structure symmetry in the isocyanate compound, so the tensile strength of the adhesive is From the viewpoint of better physical properties such as strength and elongation at break, aliphatic diisocyanate compounds and alicyclic diisocyanate compounds are preferred, aliphatic diisocyanate compounds are more preferred, and aliphatic diisocyanate compounds having 4 to 6 carbon atoms are further preferred. Preferably, HDI and modified HDI are particularly preferred, and HDI and isocyanurate modified products of HDI are most preferred.

As the diisocyanate compound (B) for producing the hydroxyl group-terminated urethane prepolymer (X), the above-mentioned aliphatic diisocyanate compound, cycloaliphatic diisocyanate compound, aromatic diisocyanate compound, or araliphatic diisocyanate compound is prepolymerized with diol. A bifunctional isocyanate group-terminated urethane prepolymer (B1) may also be used.
Examples of diols for producing the isocyanate group-terminated urethane prepolymer (B1) include ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 3-methyl-1,5-pentanediol. , 1,6-hexanediol and the like. One type of diol may be used alone or two or more types may be used in combination.
Among these, ethylene glycol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5- Pentanediol and 1,6-hexanediol are preferred, and propylene glycol is more preferred.
The isocyanate index when producing the isocyanate group-terminated urethane prepolymer (B1) is greater than 100. The isocyanate index is a value obtained by multiplying by 100 the ratio of the number of moles of the isocyanate group of the diisocyanate compound (B) to the number of moles of the hydroxyl group of the diol.
Examples of commercially available bifunctional isocyanate group-terminated urethane prepolymers include Duranate D101, Duranate D201, and Duranate A201H (all manufactured by Asahi Kasei Corporation).

The molar ratio (isocyanate index) of the isocyanate groups possessed by the diisocyanate compound (B) to the hydroxyl groups possessed by the polymer (A) is not particularly limited, but is preferably 20 or more, more preferably 30 or more, and still more preferably 40 or more. It is also preferably 90 or less, more preferably 70 or less, and still more preferably 50 or less. When the molar ratio is within the preferable range, a hydroxyl-terminated urethane prepolymer (X) having an appropriate molecular chain length can be produced, which further improves productivity. The isocyanate index is a value obtained by multiplying by 100 the ratio of the number of moles of isocyanate groups in the diisocyanate compound (B) to the number of moles of hydroxyl groups in the polymer (A).

The diisocyanate compound (B) content is not particularly limited, but is preferably 0.1 parts by mass or more, more preferably 0.4 parts by mass or more, and even more preferably 0. .7 parts by mass or more, and preferably 8 parts by mass or less, more preferably 4 parts by mass or less, still more preferably 2 parts by mass or less.

-Production method of hydroxyl group-terminated urethane prepolymer (X)-
The method for producing the hydroxyl-terminated urethane prepolymer (X) is not particularly limited, but includes a method of reacting the polymer (A) with the diisocyanate compound (B).
The average number of hydroxyl groups in the hydroxyl-terminated urethane prepolymer (X) is not particularly limited, but is preferably 1.7 or more, more preferably 1.8 or more, still more preferably 1.9 or more, and preferably 7 It is .0 or less, more preferably 5.0 or less, still more preferably 3.0 or less. When the average number of hydroxyl groups in the hydroxyl-terminated urethane prepolymer (X) is within the above-mentioned preferred range, the resulting adhesive can maintain better transparency and adhesion to the substrate.
The "average hydroxyl group number f" of the hydroxyl group-terminated urethane prepolymer (X) is the average of the polymer (A) unless the hydroxyl group-terminated urethane prepolymer (X) has an oxyalkylene group-containing component other than the polymer (A). It is the number of hydroxyl groups.

The hydroxyl-terminated urethane prepolymer (X) can also contain a polyol other than the polymer (A) as an optional component.
Examples of polyols other than the polymer (A) include polyester polyols, poly(meth)acrylic polyols, polycarbonate polyols, polyolefin polyols, and castor oil polyols, and [0016] to [ of JP 2020-37689 A] [0028] can be used without particular limitation. It is also possible to use polymer polyols in which a polymer having units based on (meth)acrylate monomers is dispersed in a polyether polyol. The polymer polyol may be a commercially available product, such as the "Ultiflow (registered trademark)" series, the "Sharpflow (registered trademark)" series (manufactured by Sanyo Chemical Industries, Ltd.), and the "Excenol (registered trademark)". series (manufactured by AGC), etc.

It is preferable to use a hydrolyzable catalyst (C) in the production of the hydroxyl group-terminated urethane prepolymer (X).
The hydrolyzable catalyst (C) is selected from the group consisting of Sn(II), Ca(II), Mn(II), Zn(II), Co(II), Pb(II) and Bi(III). Catalysts containing at least one metal are preferred. The hydrolyzable catalyst (C) can be used alone or in combination of two or more.
As a catalyst having at least one metal selected from the group consisting of Sn(II), Ca(II), Mn(II), Zn(II), Co(II), Pb(II) and Bi(III) For example, a hydrolyzable tin-based catalyst such as tin (II) 2-ethylhexanoate (Neostan U-28, product name of Nitto Kasei Co., Ltd.), dibutyltin-based catalyst (Neostan U-100, product name of Nitto Kasei Co., Ltd.) ; Hydrolyzable calcium-based catalysts such as calcium 2-ethylhexanoate; Hydrolyzable manganese-based catalysts such as manganese acetylacetonate; Hydrolyzable zinc-based catalysts such as zinc diacetylacetonate; Hydrolysis of cobalt acetylacetonate, etc. Hydrolyzable lead-based catalysts; Hydrolyzable bismuth-based catalysts such as tris(2-ethylhexanoate) bismuth (III) (Neostan U-600, Nitto Kasei Co., Ltd. product name).
The amount of the hydrolyzable catalyst (C) used is not particularly limited, but is preferably at least 0.001 parts by mass, more preferably 0.001 parts by mass or more, based on 100 parts by mass of the polymer (A). 0.002 parts by mass or more, more preferably 0.003 parts by mass or more, and preferably 1.0 parts by mass or less, more preferably 0.2 parts by mass or less, and even more preferably 0.05 parts by mass or less.

Suitable chelate ligands for the hydrolyzable catalyst (C) are not particularly limited, and include, for example, acetylacetonate (2,4-pentanedionate), 2,2,6,6-tetramethyl-3, 1,3 such as 5-heptanedioate, 1,3-diphenyl-1,3-propanedionate (dibenzoyl methanate), 1-phenyl-1,3-butananedionate, 2-acetylcyclohexanoate, etc. -Diketonate; Methyl acetoacetate, ethylacetoacetate, ethyl-2-methylacetoacetate, ethyl-2-ethylacetoacetate, ethyl-2-hexylacetoacetate, ethyl-2-phenylacetoacetate, propylacetoacetate, isopropylacetoacetate , butylacetoacetate, tert-butylacetoacetate, ethyl-3-oxovalerate, ethyl-3-oxohexanoate, 2-oxocyclohexanecarboxylic acid ethyl esterate, and other 1,3-ketoesterates; N,N -diethyl-3-oxobutaneamidate, N,N-dibutyl-3-oxobutaneamidate, N,N-bis(2-ethylhexyl)-3-oxobutaneamidate, N,N-bis(2 -methoxyethyl)-3-oxobutane amidate, N,N-dibutyl-3-oxoheptane amidate, N,N-bis(2-methoxyethyl)-3-oxoheptane amidate, N,N-bis( 2-ethylhexyl)-2-oxocyclopentanecarboxyamidate, N,N-dibutyl-3-oxo-3-phenylpropanamidate, N,N-bis(2-methoxyethyl)-3-oxo-3 - 1,3-ketoamidates such as phenylpropanamidate; Oxyalkylene-1,3-ketoamidate;

In addition to at least one of the chelating ligands for the hydrolyzable catalyst (C) mentioned above, the metal chelate complex contains further non-chelating ligands, in particular methanolates, ethanolates, propanolates, isopropanolates, butanolates, Alcoholates such as tert-butanolate, isobutanolate, pentanolate, neopentanolate, hexanolate, octanolate or 2-ethylhexanolate; formate, acetate, propionate, butanoate, isobutanoate, pentanoate, hexanoate, cyclohexanoate, heptanoate, octanoate, Carboxylates such as 2-ethylhexanoate, nonanoate, decanoate, neodecanoate, undecanoate, dodecanoate, lactate, oleate, citrate, benzoate, salicylate, and phenylacetate.

Furthermore, the hydrolyzable catalyst (C) may be, for example, an alkylmercaptoester such as a dialkyltindialkylmercaptoacetate catalyst.

A solvent may be used in the production of the hydroxyl-terminated urethane prepolymer (X), if necessary.
Examples of the solvent include ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; and aromatic hydrocarbons such as toluene and xylene. One type of solvent can be used alone or two or more types can be used in combination.
When using a solvent, the amount of the solvent to be used is not particularly limited, but is preferably 30 parts by mass or more, more preferably 40 parts by mass, based on a total of 100 parts by mass of the polymer (A) and the diisocyanate compound (B). The amount is at least 50 parts by mass, more preferably at least 50 parts by mass, and is preferably at most 500 parts by mass, more preferably at most 450 parts by mass, even more preferably at most 400 parts by mass.

Examples of the method for producing the hydroxyl group-terminated urethane prepolymer (X) include the following methods.
Production method 1: Method of charging diisocyanate compound (B), polymer (A), optional hydrolyzable catalyst (C), and arbitrary solvent all at once Production method 2: Polymer (A), optional hydrolysis In the case of production method 2, the low molecular weight components in the raw materials are preferentially reacted, and the molecular weight distribution can be made narrower. , it becomes easier to control the reaction.

The reaction temperature is preferably 50°C or higher, more preferably 60°C or higher, even more preferably 65°C or higher, and lower than 100°C, more preferably 95°C or lower, even more preferably 80°C or lower. When the reaction temperature is within the above range, side reactions other than the urethanization reaction can be easily suppressed, making it easier to obtain the desired prepolymer.

After the reaction is completed, a reaction terminator may be added to inactivate the hydrolyzable catalyst (C). Examples of the reaction terminator include acetylacetone. Two or more types of reaction terminators may be used in combination.

The weight average molecular weight (Mw) of the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited, but is preferably 15,000 or more, more preferably 18,000 or more, even more preferably 21,000 or more, and Preferably it is 100,000 or less, more preferably 80,000 or less, still more preferably 60,000 or less. When the weight average molecular weight is within the above preferred range, an aqueous pressure-sensitive adhesive composition with excellent coating properties can be obtained, and the viscosity during synthesis can be adjusted.
The weight average molecular weight (Mw) of the hydroxyl group-terminated urethane prepolymer (X) can be determined by GPC measurement in the same manner as for the above polymer (A).

The content of EO units based on the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is not particularly limited as long as it is 15% by mass or more and 90% by mass or less, but is preferably 23% by mass or more, more preferably 26% by mass or more. The content is at least 29% by mass, more preferably at least 29% by mass, and is preferably at most 65% by mass, more preferably at most 60% by mass, even more preferably at most 55% by mass. When the EO unit content with respect to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X) is at least the lower limit, the water solubility of the hydroxyl group-terminated urethane prepolymer (X) is improved, and the oxypropylene groups in the prepolymer ( The presence of the polar group (polar group) increases the affinity with the mold release agent (silicone), improves the coatability of the aqueous adhesive composition containing the hydroxyl group-terminated urethane prepolymer (X), and further improves the resulting adhesive. further improve transparency. When the EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl-terminated urethane prepolymer (X) is less than or equal to the upper limit, haze of the resulting pressure-sensitive adhesive is easily suppressed and transparency is easily improved.
The EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl-terminated urethane prepolymer (X) was calculated by determining the monomer composition of the oxyalkylene chain using ¹ H-NMR.
When the raw materials and the amount used during synthesis are known, the EO unit content relative to the total amount of oxyalkylene groups in the hydroxyl-terminated urethane prepolymer (X) is determined by It can be calculated as "the content ratio of ethylene groups".

<Polyisocyanate compound (Y)>
The polyisocyanate compound (Y) is a compound having two or more isocyanate groups in one molecule. Further, the polyisocyanate compound (Y) may be a blocked isocyanate that becomes a polyisocyanate compound by deblocking or the like.

The viscosity of the polyisocyanate compound (Y) at 25° C. is preferably 10,000 mPa·s or less, more preferably 7,000 mPa·s or less, from the viewpoint of easy mixing with the hydroxyl-terminated urethane prepolymer (X) and the temperature-sensitive catalyst (Z). 000 mPa·s or less, more preferably 5,000 mPa·s or less, further preferably 20 mPa·s or more, more preferably 100 mPa·s or more, still more preferably 200 mPa·s or more.
The viscosity of the polyisocyanate compound (Y) at 25°C can be measured with an E-type viscometer.

The polyisocyanate compound (Y) is preferably a water-dispersible polyisocyanate compound, and from the viewpoint of suppressing yellowing of the adhesive, aliphatic polyisocyanates and alicyclic polyisocyanates are preferred. At least one selected from the group consisting of is more preferred, and aliphatic polyisocyanate is even more preferred. Examples of water-dispersible polyisocyanate compounds include polyisocyanate compounds modified with hydrophilic groups such as polyethylene oxide, carboxyl groups, and sulfonic acid groups to make them self-emulsifying (self-emulsifying polyisocyanate compounds); surfactants, etc. Compounds that are emulsified and made water-dispersible (forced emulsification type polyisocyanate compounds);
Specific examples of the polyisocyanate compound (Y) include tetramethylene diisocyanate, pentamethylene diisocyanate, hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, dodeca Linear or branched aliphatic polyisocyanates such as methylene diisocyanate, lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate; toluene diisocyanate (TDI), 2,2'- Diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), α Aromatic polyisocyanates such as , α, α', α'-tetramethylxylylene diisocyanate, 4,4'-dibenzyl diisocyanate, toridine diisocyanate, 1,5-naphthalene diisocyanate; isophorone diisocyanate (IPDI), 4,4' -Dicyclohexylmethane diisocyanate (HMDI), norbornane diisocyanate (NBDI), hydrogenated xylylene diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, dicyclohexylmethane diisocyanate (H12MDI), etc. Alicyclic polyisocyanate; isocyanurate modified products of the various diisocyanate compounds mentioned above; biuret modified products of the various diisocyanate compounds mentioned above; allophanate modified products of the various diisocyanate compounds mentioned above; Examples thereof include a bifunctional or more isocyanate group-terminated urethane prepolymer (adduct modified product) obtained by reacting with a polyol having a hydroxyl group as described above; an unblocked product of blocked isocyanate; and the like. These may be used alone or in combination of two or more.

Examples of commercially available modified isocyanurate products include Duranate TPA-100, Duranate TKA-100 (manufactured by Asahi Kasei Corporation), and Coronate HX (manufactured by Tosoh Corporation).
Examples of commercially available biuret modified products include Duranate 24A-100 and Duranate 22A-75P (manufactured by Asahi Kasei Corporation).
Commercially available trifunctional or higher isocyanate group-terminated urethane prepolymers include, for example, Coronate L, Coronate L-55E, Coronate L-45E (all manufactured by Tosoh Corporation), and the like.
Commercially available water-dispersible polyisocyanates include, for example, Duranate WB40-100, Duranate WB40-80D, Duranate WT20-100, Duranate WT30-100, Duranate WL70-100, Duranate WE50-100, Duranate WR80-70P (all Asahi Kasei Corporation), Aquanate 105, Aquanate 130, Aquanate 140 (AQ-140), Aquanate 200, Aquanate 210 (all manufactured by Tosoh Corporation), Takenate WD series (Takenate WD-720, Takenate WD-725) , Takenate WD-220, Takenate XWD-HS7, Takenate XWD-HS30, etc.) (all manufactured by Mitsui Chemicals), Bayhydur3100, Bayhydur ASF company ), etc.
Commercially available blocked isocyanates include, for example, SU-268A, NBP-211, Meikanate CX, Meikanate TP-10, DM-6400 (all manufactured by Meisei Kagaku Kogyo Co., Ltd.); WM44-L70G (manufactured by Asahi Kasei Corporation); Aqua Examples include BI200, Aqua BI220 (all manufactured by Baxenden Chemicals); Takelac W, Takelac WPB (all manufactured by Mitsui Chemicals); Burnock (manufactured by DIC); Elastron (manufactured by Daiichi Kogyo); and the like.

The isocyanate index when producing the aqueous adhesive composition of the present invention by reacting the hydroxyl-terminated urethane prepolymer (X) with the polyisocyanate compound (Y) is preferably over 100, more preferably 105 or more. , more preferably 150 or more, and preferably 2,000 or less, more preferably 1,750 or less, still more preferably 1,500 or less. The isocyanate index is a value obtained by multiplying by 100 the ratio of the number of moles of isocyanate groups in the polyisocyanate compound (Y) to the number of moles of hydroxyl groups in the hydroxyl group-terminated urethane prepolymer (X).

The content of the polyisocyanate compound (Y) is not particularly limited, but is preferably 1 part by mass or more, more preferably 1.5 parts by mass or more, and more preferably 1 part by mass or more, based on 100 parts by mass of the hydroxyl-terminated urethane prepolymer (X). The amount is preferably 2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 6 parts by mass or less, and even more preferably 4 parts by mass or less.

<Temperature-sensitive catalyst (Z)>
As long as the temperature-sensitive catalyst (Z) is a catalyst that observes an exothermic peak with a maximum heat flow of 1 mcal/s or more in the temperature range of 30 to 90°C in the above-mentioned predetermined differential scanning calorimetry (DSC) There is no particular restriction, and at least one selected from the group consisting of piperazine-based amine catalysts, morpholine-based amine catalysts, and diazabicyclo compound-based catalysts is preferred, and diazabicyclo compound-based catalysts have better reactivity. More preferred.

Examples of the piperazine-based amine catalyst include dimethylpiperazine, N-methyl-N'-(2-dimethylamino)ethylpiperazine, and N-methyl-N'-(2-hydroxyethyl)piperazine.

Examples of the morpholine amine catalyst include N-methylmorpholine, N-ethylmorpholine, and the like.

The diazabicyclo compound catalyst means a bicyclo compound having strong basicity derived from an amidine moiety. For example, 1,8-diazabicyclo-[5,4,0]-undecene-7 (abbreviated as DBU), 1,5-diazabicyclo-[4,3,0]-nonene-5 (abbreviated as DBN), 1,8- Examples include diazabicyclo-[5,3,0]-decene-7 (abbreviated as DBD) and 1,4-diazabicyclo-[3,3,0]-octene-4 (abbreviated as DBO). Further, organic salts such as triazole salts, phenol salts, formates, octylates, and oleates may also be mentioned.

As the temperature-sensitive catalyst (Z), triazole salts, phenol salts, formates, octylates, and oleates of DBU; triazole salts, phenol salts, and formic acid salts of DBN are used because of their better reactivity. Triazole salts of DBD; triazole salts of DBO are preferred; triazole salts, octylates of DBU; triazole salts, octylates of DBN; triazole salts of DBD; triazoles of DBO Salts are more preferred, and triazole salts and octylate salts of DBU; octylate salts of DBN are even more preferred.

The content of the temperature-sensitive catalyst (Z) is not particularly limited, but is preferably 0.001 parts by mass or more, more preferably 0.005 parts by mass, based on 100 parts by mass of the hydroxyl-terminated urethane prepolymer (X). Above, the amount is more preferably 0.008 parts by mass or more, preferably 3 parts by mass or less, more preferably 1 part by mass or less, and still more preferably 0.1 parts by mass or less.

<Water>
The content of water in the aqueous composition for adhesives of the present invention is preferably 40% by mass or more, more preferably 44% by mass or more, even more preferably 48% by mass or more, and preferably 90% by mass or less. , more preferably 85% by mass or less, still more preferably 80% by mass or less.
When the content is within the above range, coating properties can be further improved.

<Other ingredients>
The aqueous composition for adhesives of the present invention contains, as other components, an antioxidant; a solvent such as alcohol; a hydrolysis inhibitor; an ultraviolet absorber; a light stabilizer; an antistatic agent; a leveling agent; an alkylene oxide, a polyol ( (initiator), a catalyst for ring-opening addition polymerization of alkylene oxide, raw materials used in preparing the hydroxyl-terminated urethane prepolymer (X) such as diisocyanate; and other optional components.
The content of other components in the aqueous adhesive composition of the present invention is usually 20% by mass or less.

-Antioxidant-
Examples of the antioxidant include radical scavengers such as phenolic compounds and amine compounds; peroxide decomposers such as sulfur compounds and phosphorus compounds; and the like. The antioxidants may be used alone or in combination of two or more.

Examples of phenolic compounds include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-methylphenol, 2,6-di-t- Butyl-4-ethylphenol, stearin-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2 '-Methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol) , 2,2'-dihydroxy-3,3'-di(α-methylcyclohexyl)-5,5'-dimethyldiphenylmethane (Seiko Chemical Co., Ltd. product name: CBP) 3,9-bis[1,1-dimethyl-2- [β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, benzenepropanoic acid, 3,5- Bis(1,1-dimethylethyl)-4-hydroxy-, C7-C9 side chain alkyl ester (BASF product name Irganox 1135), 2,6-di-t-butyl-4-(4,6-bis(octylthio) )-1,3,5-triazin-2-ylamino)phenol (BASF product name Irganox565), 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1, 3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl) -4'-hydroxyphenyl)propionate] methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid] glycol ester, 1,3,5-tris(3 ',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H, 3H, 5H) trione, tocopherol, and the like.

Examples of the amine compound include a reaction product of N-phenylbenzenamine and 2,4,4-trimethylpentene (trade name: IRGANOX® 5057 (manufactured by BASF Japan)), tris(2-[ (2,4,8,10-tetrakisbutyldibenzo[d,f][1,3,2]dioxaphosphepin-6-yl)oxy]ethyl)amine, and the like.

Examples of sulfur-based compounds include didodecyl-3,3'-thiopropionate, dilauryl-3,3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, dimyristyl-3,3' -thiodipropionate, distearyl-3,3'-thiodipropionate, tetrakis-methylene-3-laurylthiopropionate methane, distearyl-3,3'-methyl-3,3'-thiodipropio nate, laurylstearyl-3,3'-thiodipropionate, bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl] sulfide, β-laurylthiopropionate, Examples include 2-mercaptobenzimidazole, 2-mercapto-5-methylbenzimidazole, distearyl-3,3'-thiodiprothionate, and the like.

Examples of phosphorus compounds include triphenyl phosphite, diphenylisodecyl phosphite, 4,4'-butylidene-bis(3-methyl-6-tert-butylphenylditridecyl) phosphite, and cyclic neopentanetetrayl. Bis(octadecyl phosphite), tris(nonylphenyl) phosphite, tris(monononylphenyl) phosphite, tris(dinonylphenyl) phosphite, diisodecylpentaerythritol diphosphite, 9,10-dihydro-9-oxa- 10-phosphaphenanthrene-10-oxide, 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10 -Desyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene, tris(2,4-di-tert-butylphenyl)phosphite, cyclic neopentanetetrayl bis(2,4-di-tert -butylphenyl) phosphite, cyclic neopentanetetrylbis(2,6-di-tert-butyl-4-methylphenyl) phosphite, 2,2-methylenebis(4,6-di-tert-butylphenyl) Examples include octyl phosphite.

By using an antioxidant, thermal deterioration of the hydroxyl group-terminated urethane prepolymer (X) can be prevented.
The amount of antioxidant added is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably is 0.2 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less.

As the antioxidant, from the viewpoint of stability and antioxidant effect, it is preferable to use one or more phenolic compounds which are radical scavengers. One or more phenolic compounds that are radical scavengers and one or more phosphorus compounds that are peroxide decomposers can also be used together. Further, as the antioxidant, a phenol compound which is a radical scavenger and a phosphorus compound which is a peroxide decomposer can be used in combination, and these antioxidants and a hydrolysis inhibitor described below can also be used in combination.

-solvent-
The aqueous composition for adhesives of the present invention may contain a solvent, if necessary.
As for the type of solvent, the above-mentioned solvents that can be used for producing the hydroxyl group-terminated urethane prepolymer (X) are preferable. One type of solvent can be used alone or two or more types can be used in combination.
The amount of the solvent to be used is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably It is 5 parts by mass or less.

-Hydrolysis inhibitor-
Examples of hydrolysis inhibitors include carbodiimide-based, oxazoline-based, epoxy-based, and the like. The hydrolysis inhibitors may be used alone or in combination of two or more.
Among these, carbodiimide type is preferred from the viewpoint of hydrolysis inhibiting effect.

--Carbodiimide--
A carbodiimide-based hydrolysis inhibitor is a compound having one or more carbodiimide groups in one molecule.
Examples of the monocarbodiimide compound include dicyclohexylcarbodiimide, diisopropylcarbodiimide, dimethylcarbodiimide, diisobutylcarbodiimide, dioctylcarbodiimide, diphenylcarbodiimide, naphthylcarbodiimide, and the like.
A polycarbodiimide compound can be produced by subjecting a diisocyanate to a decarboxylation condensation reaction in the presence of a carbodiimidation catalyst.
Examples of the diisocyanate include 4,4'-diphenylmethane diisocyanate (MDI), 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, 3,3'-dimethyl-4,4'-diphenylmethane diisocyanate, 4,4 '-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4-diisocyanate, isophorone diisocyanate, Examples include 4,4'-dicyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate.
Examples of the carbodiimidation catalyst include 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, 1-ethyl-3-methyl-2-phospholene-1-oxide, 1- Examples include phosphorene oxides such as ethyl-2-phospholene-1-oxide and 3-phosphorene isomers thereof.

Examples of oxazoline hydrolysis inhibitors include 2,2'-o-phenylenebis(2-oxazoline), 2,2'-m-phenylenebis(2-oxazoline), and 2,2'-p-phenylenebis(2-oxazoline). (2-oxazoline), 2,2'-p-phenylenebis(4-methyl-2-oxazoline), 2,2'-m-phenylenebis(4-methyl-2-oxazoline), 2,2'-p -phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-m-phenylenebis(4,4'-dimethyl-2-oxazoline), 2,2'-ethylenebis(2-oxazoline) , 2,2'-tetramethylenebis(2-oxazoline), 2,2'-hexamethylenebis(2-oxazoline), 2,2'-octamethylenebis(2-oxazoline), 2,2'-ethylenebis (4-methyl-2-oxazoline), 2,2'-diphenylenebis(2-oxazoline), and the like.

Examples of epoxy hydrolysis inhibitors include diglycidyl ethers of aliphatic diols such as 1,6-hexanediol, neopentyl glycol, and polyalkylene glycol; sorbitol, sorbitan, polyglycerol, pentaerythritol, diglycerol, glycerol, Polyglycidyl ethers of aliphatic polyols such as trimethylolpropane; polyglycidyl ethers of alicyclic polyols such as cyclohexanedimethanol; aliphatic acids such as terephthalic acid, isophthalic acid, naphthalene dicarboxylic acid, trimellitic acid, adipic acid, and sebacic acid or diglycidyl ester or polyglycidyl ester of aromatic polyhydric carboxylic acid; resorcinol, bis-(p-hydroxyphenyl)methane, 2,2-bis-(p-hydroxyphenyl)propane, tris-(p-hydroxyphenyl) ) Diglycidyl ether or polyglycidyl ether of polyhydric phenols such as methane, 1,1,2,2-tetrakis(p-hydroxyphenyl)ethane; N,N-diglycidylaniline, N,N-diglycidyltoluidine, N , N,N',N'-tetraglycidyl-bis-(p-aminophenyl)methane; triglycidyl derivatives of aminopher; triglycidyl tris(2-hydroxyethyl)isocyanurate; Examples include glycidyl isocyanurate; epoxy resins such as orthocresol type epoxy resins and phenol novolac type epoxy resins; and the like.

The amount of the hydrolysis inhibitor added is not particularly limited, but is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and more preferably 0.1 parts by mass or more, based on 100 parts by mass of the hydroxyl-terminated urethane prepolymer (X). The amount is preferably 0.5 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and still more preferably 3 parts by mass or less.

-UV absorber-
Examples of the ultraviolet absorber include benzophenone compounds, benzotriazole compounds, salicylic acid compounds, oxalic acid anilide compounds, cyanoacrylate compounds, and triazine compounds. One type of ultraviolet absorber may be used alone, or two or more types may be used in combination.
The amount of the ultraviolet absorber added is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably is 0.2 parts by mass or more, and preferably 3 parts by mass or less, more preferably 2.5 parts by mass or less, still more preferably 2 parts by mass or less.

-Light stabilizer-
Examples of the light stabilizer include hindered amine compounds and hindered piperidine compounds. One kind of light stabilizer can be used alone or two or more kinds can be used in combination.

The amount of light stabilizer added is not particularly limited, but hydroxyl group-terminated urethane prepolymer (X) 10
The amount is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.2 parts by mass or more, and preferably 2 parts by mass or less, more preferably 0 parts by mass. It is 1.5 parts by mass or less, more preferably 1 part by mass or less.

-Antistatic agent-
Examples of the antistatic agent include inorganic salts, polyhydric alcohol compounds, ionic liquids, surfactants, and the like. The antistatic agents may be used alone or in combination of two or more.
Among these, ionic liquids are preferred. Note that the "ionic liquid" is also referred to as a salt molten at room temperature, and is a salt that is fluid at 25°C.

The amount of the antistatic agent added is not particularly limited, but is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, and even more preferably is 0.05 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less.

Examples of inorganic salts include sodium chloride, potassium chloride, lithium chloride, lithium perchlorate, ammonium chloride, potassium chlorate, aluminum chloride, copper chloride, ferrous chloride, ferric chloride, ammonium sulfate, potassium nitrate, and sodium nitrate. , sodium carbonate, sodium thiocyanate, and the like.

Examples of the polyhydric alcohol compound include propanediol, butanediol, hexanediol, polyethylene glycol, trimethylolpropane, pentaerythritol, and the like.

Examples of the ionic liquid include 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1,3-dimethylimidazoliumbis(trifluoromethylsulfonyl)imide, 1-butyl-3-methylimidazo Ionic liquids containing imidazolium ions such as bis(trifluoromethylsulfonyl)imide; 1-methylpyridiniumbis(trifluoromethylsulfonyl)imide, 1-butylpyridiniumbis(trifluoromethylsulfonyl)imide, 1-hexylpyridinium Bis(trifluoromethylsulfonyl)imide, 1-octylpyridiniumbis(trifluoromethylsulfonyl)imide, 1-hexyl-4-methylpyridiniumbis(trifluoromethylsulfonyl)imide, 1-hexyl-4-methylpyridinium hexafluoroline Acid acid, 1-octyl-4-methylpyridiniumbis(trifluoromethylsulfonyl)imide, 1-octyl-4-methylpyridiniumbis(fluorosulfonyl)imide, 1-methylpyridiniumbis(perfluoroethylsulfonyl)imide, 1- Ionic liquids containing pyridinium ions such as methylpyridinium bis(perfluorobutylsulfonyl)imide; trimethylheptylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-propylammonium bis(trifluoromethanesulfonyl) ) imide, N,N-diethyl-N-methyl-N-pentylammonium bis(trifluoromethanesulfonyl)imide, N,N-diethyl-N-methyl-N-heptylammonium bis(trifluoromethanesulfonyl)imide, tri-n - Ionic liquids containing ammonium ions such as butylmethylammonium bistrifluoromethanesulfonimide; other ionic liquids such as pyrrolidinium salts, phosphonium salts, and sulfonium salts; and the like.

Examples of surfactants include nonionic low molecules such as glycerin fatty acid ester, polyoxyalkylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene alkylamine, polyoxyethylene alkylamine fatty acid ester, and fatty acid diethanolamide. Surfactant: Anionic low molecular surfactant such as alkyl sulfonate, alkylbenzene sulfonate, alkyl phosphate; Cationic low molecular surfactant such as tetraalkylammonium salt, trialkylbenzylammonium salt; Alkyl betaine , amphoteric low-molecular surfactants such as alkylimidazolium betaine; nonionic polymeric surfactants such as polyether ester amide type, ethylene oxide-epichlorohydrin type, and polyether ester type; anionic such as polystyrene sulfonic acid type. Cationic polymer surfactants such as acrylate polymer type containing quaternary ammonium base; Amino acid type amphoteric surfactants such as higher alkylaminopropionates, higher alkyl dimethyl betaines, higher alkyl dihydroxy Examples include amphoteric polymer surfactants such as betaine-type amphoteric surfactants such as ethyl betaine.

-Leveling agent-
Examples of the leveling agent include acrylic leveling agents, fluorine leveling agents, silicone leveling agents, and the like. One type of leveling agent may be used alone, or two or more types may be used in combination.
Among these, acrylic leveling agents are preferred.
The amount of the leveling agent added is not particularly limited, but is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably The amount is 0.1 parts by mass or more, and preferably 2 parts by mass or less, more preferably 1.5 parts by mass or less, and even more preferably 1 part by mass or less.

-Other optional ingredients-
Other optional components include, for example, resins other than the hydroxyl-terminated urethane prepolymer (X), fillers (talc, calcium carbonate, titanium oxide, etc.), metal powder, coloring agents (pigments, etc.), and foil-like materials. , a softener, a conductive agent, a silane coupling agent, a lubricant, a corrosion inhibitor, a heat stabilizer, a polymerization inhibitor, an antifoaming agent, and the like.

<Method for producing aqueous composition for adhesive>
A method for producing the aqueous composition for an adhesive of the present invention, which includes a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z), will be described.

The aqueous composition for an adhesive of the present invention may be a one-part type containing a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z). The aqueous pressure-sensitive adhesive composition of the present invention may be a two-part composition containing a first part containing a hydroxyl-terminated urethane prepolymer (X) and a second part containing a polyisocyanate compound (Y). Note that here, the temperature-sensitive catalyst (Z) may be contained in either the first part or the second part, or may be contained in both the first part and the second part.
By heating the aqueous adhesive composition containing the hydroxyl-terminated urethane prepolymer (X), the polyisocyanate compound (Y), and the temperature-sensitive catalyst (Z), the formation of urethane bonds progresses, resulting in adhesive agent is obtained.
The aqueous composition for adhesives of the present invention may further contain catalysts other than the temperature-sensitive catalyst (Z), solvents, and optional components that can be blended into the aqueous composition for adhesives.
In the case of a two-component type, the first agent and the second agent are each housed in separate containers. Various containers such as tubes and bottles can be used.

The reaction temperature when curing the aqueous composition for adhesives of the present invention is preferably 30°C or higher, more preferably 35°C or higher, even more preferably 40°C or higher, and 140°C or lower, more preferably 130°C or higher. The temperature is preferably 120°C or lower, more preferably 120°C or lower. When the reaction temperature is within the above range, side reactions other than the urethanization reaction can be easily suppressed, making it easier to obtain the desired polymer.

(adhesive)
The adhesive of the present invention is obtained by curing the aqueous composition for adhesives of the present invention.
The content of EO units based on the total amount of oxyalkylene groups in the adhesive of the present invention is not particularly limited, but is preferably 10% by mass or more, more preferably 12% by mass or more, and even more preferably 15% by mass or more, Even more preferably 20% by mass or more, particularly preferably 25% by mass or more, and preferably 70% by mass or less, more preferably 60% by mass or less, even more preferably 50% by mass or less, particularly preferably 40% by mass or less. mass% or less. When the EO unit content relative to the total amount of oxyalkylene groups in the adhesive of the present invention is at least the lower limit, haze of the adhesive is easily suppressed and transparency is easily improved. When the EO unit content relative to the total amount of oxyalkylene groups in the adhesive of the present invention is below the upper limit, the adhesiveness of the adhesive to the base material is more likely to be improved.
The EO unit content relative to the total amount of oxyalkylene groups in the adhesive was calculated by determining the monomer composition of the oxyalkylene chain using ¹³ C-NMR.

<Method for manufacturing adhesive>
A method for producing the adhesive of the present invention by reacting a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z) will be described.
In the method for producing an adhesive, an aqueous composition for an adhesive is prepared by mixing a hydroxyl-terminated urethane prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z). The substance is coated onto a base material, and the base coated with the aqueous adhesive composition is heated.

<<Mixing>>
The mixing of the hydroxyl group-terminated urethane prepolymer (X), the polyisocyanate compound (Y), and the temperature-sensitive catalyst (Z) (preparation of an aqueous composition for adhesive) is performed at a temperature lower than the exothermic peak temperature of the temperature-sensitive catalyst (Z). It is also carried out at low temperatures.
There are no particular restrictions on the mixing method for mixing the hydroxyl-terminated urethane prepolymer (X), the polyisocyanate compound (Y), and the temperature-sensitive catalyst (Z), and conventionally known methods such as dispersion mixing using a roll mill can be used. , mixing using a rotary blade, mixing using a planetary stirring mixer, mixing using a homogenizer, mixing using a kneader, and the like.

＜＜Coating＞＞
The coating method for coating the aqueous adhesive composition on the substrate is not particularly limited, and conventionally known methods such as spray coating, bar coating, knife coating, roll coating, Examples include a blade coating method, a die coating method, and the like.

<<Heating>>
The substrate coated with the aqueous adhesive composition is heated at a temperature higher than the exothermic peak temperature of the temperature-sensitive catalyst (Z).

(Packing material)
The adhesive patch of the present invention includes a base material and an adhesive layer containing the adhesive of the present invention provided on at least one surface of the base material.
The patch of the present invention preferably has an adhesive layer on one side of the base film, and a release liner or carrier film that is removably laminated to cover the adhesive surface of the adhesive layer.
The patch of the present invention can be applied, for example, by applying an aqueous adhesive composition in which the adhesive of the present invention is dissolved (dispersed) in water onto a carrier film using a coating applicator. It is produced by drying the aqueous composition for an adhesive to form an adhesive layer, laminating a base film on the surface of the formed adhesive layer opposite to the carrier film, and curing.
In addition, the patch of the present invention can be produced by, for example, applying the aqueous composition for an adhesive of the present invention onto a carrier film using a coating applicator, and drying the applied aqueous composition for an adhesive. It is produced by forming a resin layer, laminating a base film on the surface of the formed resin layer opposite to the support film, and curing to form an adhesive layer.
Here, in the above method for producing a patch, an adhesive layer (resin layer) is formed on a carrier film, and a base film is placed on the surface of the formed adhesive layer (resin layer) opposite to the carrier film. Instead of laminating, an adhesive layer (resin layer) may be formed on the base film, and a support film may be laminated on the surface of the formed adhesive layer (resin layer) opposite to the base film. .

The thickness of the base film is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, and even more preferably It is 50 μm or less. When the thickness of the base film is within the above-mentioned preferred range, the possibility that the patch will break can be reduced.

Materials for the base film include, for example, urethane polymers such as polyether urethane and polyester urethane; amide polymers such as polyether polyamide block polymer; acrylic polymers such as polyacrylate; polyethylene, polypropylene, and ethylene/vinyl acetate. Examples include olefin polymers such as polymers; ester polymers such as polyether polyester; and the like. Ester polymers are preferred as the material for the base film.
The materials for the base film may be used alone or in combination of two or more. Furthermore, a laminated film in which base films manufactured from different materials are laminated may be used. The base film can be laminated with fabrics such as woven fabrics, nonwoven fabrics, knitted fabrics, or nets.

The thickness of the adhesive layer is not particularly limited, but is preferably 5 μm or more, more preferably 10 μm or more, even more preferably 20 μm or more, and preferably 100 μm or less, more preferably 50 μm or less, and even more preferably 30 μm. It is as follows. When the thickness of the adhesive layer is within this range, better adhesiveness can be obtained.

In order to prevent contamination of the surface of the adhesive layer of the adhesive material of the present invention, it is preferable that the surface of the adhesive layer is covered with a release liner or a carrier film until use.
Specifically, the release liner is one in which the surface of high-quality paper, glassine paper, parchment paper, etc. is coated with a release agent having release properties such as silicone resin or fluororesin; or one in which high-quality paper is anchor-coated with a resin. Alternatively, it is possible to use a material obtained by laminating high-quality paper with polyethylene, the surface of which is coated with a release agent having release properties such as silicone resin or fluororesin.
Although there are no particular limitations on the material of the carrier film, plastic films such as polyester films are preferred. A support film can be releasably laminated on the surface of the base film opposite to the surface on which the adhesive layer is formed.
In order to releasably bond the carrier film to the back surface of the base film, a method such as inflation molding, extrusion lamination, lamination molding, or casting can be used.
The thickness of the supporting film varies depending on the material, but is preferably 15 μm or more, more preferably 20 μm or more, even more preferably 30 μm or more, and preferably 200 μm or less, more preferably 100 μm or less, and still more preferably 50 μm or less. It is.

(Adhesive tape)
The adhesive tape of the present invention has a base material and an adhesive layer containing the adhesive of the present invention provided on at least one surface of the base material.
In the adhesive tape of the present invention, the adhesive layer may be provided only on one surface of the base material, or may be provided on both surfaces of the base material.

One form of the adhesive tape of the present invention preferably has an adhesive layer provided on one side of a base film, and a release liner or a carrier film that is releasably laminated to cover the adhesive surface of the adhesive layer. . This form is particularly referred to as a single-sided adhesive tape.
The base film, release liner, and carrier film are the same as in the patch of the present invention. Further, the thickness of the adhesive layer is the same as the thickness of the adhesive layer in the patch of the present invention.
Further, the adhesive tape of the present invention can be manufactured in the same manner as the adhesive material of the present invention.

Another form of the adhesive tape of the present invention may include an adhesive layer provided on both sides of the base film, and a release liner or a carrier film releasably laminated to cover the adhesive surface of the adhesive layer. preferable. This form is especially called double-sided adhesive tape.
The base film, release liner, and carrier film are the same as in the patch of the present invention. Further, the thickness of the adhesive layer is the same as the thickness of the adhesive layer in the patch of the present invention.

Still another form of the adhesive tape of the present invention is that an adhesive layer is provided on one side of a releasable base film, and a release liner or a carrier film is releasably laminated to cover the adhesive surface of the adhesive layer. It is preferable to have. This form is particularly referred to as an adhesive transfer tape.
The peelable base film is preferably a base film that can be used in the adhesive patch of the present invention, and the surface of the base film is coated with a release agent having peelability such as a silicone resin or a fluororesin. The release liner and carrier film are the same as in the patch of the present invention. Further, the thickness of the adhesive layer is the same as the thickness of the adhesive layer in the patch of the present invention.

Hereinafter, the present invention will be explained in detail by way of examples. However, the present invention is not limited to the following examples.
Examples 1 to 7 and 10 to 13 are examples, and Examples 8 to 9 are comparative examples.

<Method for measuring physical properties>
[Hydroxyl value]
The hydroxyl value of the oxyalkylene polymer was calculated in accordance with Method B of JIS K 1557:2007 using a phthalating reagent.
[Molecular weight converted to hydroxyl value]
The molecular weight in terms of hydroxyl value of the oxyalkylene polymer is a value calculated from the formula: 56100/(hydroxyl value)×(number of hydroxyl groups in one molecule). In addition, "the number of hydroxyl groups in one molecule" is the number of hydroxyl groups or the average number of hydroxyl groups of the oxyalkylene polymer.

[Mn, Mw, Mw/Mn]
The number average molecular weight Mn, weight average molecular weight Mw, and molecular weight distribution Mw/Mn of the oxyalkylene polymer and the hydroxyl group-terminated urethane prepolymer are values obtained by measurement by the method described below.
As a standard sample for molecular weight measurement, several types of monodispersed polystyrene with different degrees of polymerization were measured using a commercially available GPC measurement device (HLC-8320GPC, manufactured by Tosoh Corporation), and the relationship between the molecular weight of polystyrene and retention time was determined. After creating a calibration curve and diluting the oxyalkylene polymer as the measurement sample to 0.5% by mass with tetrahydrofuran and passing it through a filter with a pore size of 0.5 μm, the measurement sample was measured using the above GPC measuring device. It was measured using Mn and Mw of the measurement sample were determined by computer analysis of the GPC spectrum of the measurement sample using the above calibration curve. Mw/Mn was calculated from the above Mw and Mn.

[Unsaturation degree]
The degree of unsaturation of the oxyalkylene polymer is a value measured according to the method of JIS K 1557-3:2007.

[Content ratio of oxyethylene group (ethylene oxide unit (EO unit) content)]
The content ratio of oxyethylene groups (EO unit content) with respect to the total amount of oxyalkylene groups in the oxyalkylene polymer, hydroxyl-terminated urethane prepolymer, and cured product (adhesive) can be determined using ¹ H-NMR as the monomer of the oxyalkylene chain. This value is calculated by determining the composition.
For example, when the oxyalkylene polymer is a polyol consisting of PO units and EO units, the EO unit content can be determined from the area ratio of the methyl group signal in the PO unit and the methylene group signal in the PO unit and EO unit. You can ask for it.

<Synthesis of oxyalkylene polymer>
[Synthesis example 1: Synthesis of polymer (A1-1)]
(Step a)
As an initiator, a polyol (initiator A) obtained by adding propylene oxide to glycerin using a KOH catalyst until the molecular weight in terms of hydroxyl value reached 3,000 was used.
First, 1,970 g of initiator A and a hexacyanocobaltate complex (hereinafter also referred to as TBA-DMC catalyst) slurry whose ligand is t-butanol were added to a pressure-resistant reaction vessel to prepare a reaction solution. The amount of the TBA-DMC catalyst slurry was such that the metal concentration of the TBA-DMC catalyst in the reaction solution was 50 mass ppm.
Next, after purging the inside of the pressure-resistant reaction vessel with nitrogen, the reaction solution was heated while stirring, and when it reached 140°C, heating was stopped, and while stirring was continued, 98 g of propylene oxide (5.0 g per 100 parts by mass of initiator) was added. (parts by mass) was fed into a pressure-resistant reaction vessel and reacted.
(Step b)
After the temperature of the reaction solution stopped rising, it was cooled to 140° C., and while stirring the reaction solution, a mixture of 2,043 g of propylene oxide and 703 g of ethylene oxide was fed into the pressure-resistant reaction vessel. After confirming that there was no change in internal pressure, the catalyst was neutralized and removed using a synthetic adsorbent (Kyoward 600S, manufactured by Kyowa Chemical Industry Co., Ltd.) to obtain a polymer (A1-1). .
Table 1 shows the number of hydroxyl groups, hydroxyl value, molecular weight in terms of hydroxyl value, Mn, Mw/Mn, degree of unsaturation, and EO unit content of the polymer (A1-1) thus obtained. Note that these values are values measured by the method described above. Table 1 also applies to oxyalkylene polymers (A1-2), (A2-1), (A2-2), (C1-1), and (C1-2) obtained in Synthesis Examples 2 to 6 below. Shown below.
In addition, the "number of hydroxyl groups" in Table 1 is the number of hydroxyl groups in the initiator used during synthesis (the number of hydroxyl groups in glycerin is 3, and the number of hydroxyl groups in propylene glycol is 2), and these numbers are This is the number of hydroxyl groups in each oxyalkylene polymer.

[Synthesis example 2: Synthesis of polymer (A1-2)]
Initiator A in (step a) was changed to a polyol (initiator B) prepared by addition-reacting propylene oxide using glycerin as an initiator and a KOH catalyst until the molecular weight in terms of hydroxyl value reached 1,000, and the mass of initiator B was changed to 1,002 g, the mass of propylene oxide in (step a) is 100 g (10.0 parts by mass for 100 parts by mass of initiator), the mass of propylene oxide in (step b) is 3,149 g, the mass of ethylene oxide is Polymer (A1-2) was synthesized in the same manner as Synthesis Example 1 except that the amount was changed to 2,845 g.

[Synthesis example 3: Polymer (A2-1) synthesis]
The initiator A in (step a) was changed to a polyol (initiator C) in which propylene glycol was used as an initiator and propylene oxide was subjected to an addition reaction using a TBA-DMC catalyst until the molecular weight in terms of hydroxyl value reached 2,000. The mass of C is 1,310 g, the mass of propylene oxide in (step a) is 130 g (10.0 parts by mass relative to 100 parts by mass of initiator), the mass of propylene oxide in (step b) is 3,554 g, ethylene oxide Polymer (A2-1) was synthesized in the same manner as Synthesis Example 1 except that the mass of was changed to 2,079 g.

[Synthesis example 4: Synthesis of polymer (A2-2)]
Initiator A in (step a) was changed to a polyol (initiator D) in which propylene glycol was used as an initiator and propylene oxide was subjected to an addition reaction with a KOH catalyst until the molecular weight in terms of hydroxyl value reached 1,000. The mass of propylene oxide in (step a) is 80 g (10.0 parts by mass per 100 parts by mass of initiator), the mass of propylene oxide in (step b) is 2,659 g, the mass of ethylene oxide is 2 Polymer (A2-2) was synthesized in the same manner as in Synthesis Example 1, except that the amount was changed to , 336 g.

[Synthesis Example 5: Synthesis of polymer (C1-1)]
(Step a)
As an initiator, a polyol (initiator E) obtained by subjecting glycerin to an addition reaction of propylene oxide with a KOH catalyst until the molecular weight in terms of hydroxyl value reached 1,500 was used.
First, 1.4 g of zinc hexacyanocobaltate-glyme complex, which is a DMC catalyst, and 1,050 g of initiator E were added to a pressure-resistant reactor to prepare a reaction solution. After purging the inside of the pressure-resistant reaction vessel with nitrogen, heat the reaction solution while stirring, stop heating when it reaches 140°C, and add 105 g of propylene oxide (10.0 parts by mass per 100 parts by mass of initiator) while continuing to stir. ) was fed into a pressure-resistant reaction vessel and reacted.
(Step b)
Under a nitrogen atmosphere at 130° C., 5,110 g of propylene oxide was reacted for 5 hours to deactivate the catalyst. After that, 22.1g of KOH catalyst was added, dehydration treatment was performed at 120℃ for 2 hours, and after alcoholation, 840g of ethylene oxide was reacted, and then a synthetic adsorbent (Kyowado 600S, manufactured by Kyowa Chemical Industry Co., Ltd.) was used to absorb the catalyst. A polymer (C1-1) in which ethylene oxide was added to the terminal was obtained by performing a removal operation.

[Synthesis Example 6: Synthesis of polymer (C1-2)]
Initiator E in (step a) was changed to a polyol (initiator F) prepared by addition-reacting propylene glycol with propylene oxide using a KOH catalyst until the molecular weight in terms of hydroxyl value reached 700, and the mass of initiator F was changed to 350 g, the mass of zinc hexacyanocobaltate-glyme complex which is the DMC catalyst in (step a) is 0.37 g, the mass of propylene oxide in (step a) is 35 g (10.0 g for 100 parts by mass of initiator) Mass part), the mass of the KOH catalyst in (step b) was changed to 6.3 g, the mass of propylene oxide in (step b) was changed to 1,490 g, and the mass of ethylene oxide was changed to 160 g. A polymer (C1-2) was synthesized.

<Manufacture example 1>
[Production of hydroxyl-terminated urethane prepolymer (X)]
As shown in Table 2, 40 parts by mass of polymer A (1-2) and 60 parts by mass of polymer A (2-2) were added to a reaction vessel equipped with a thermometer, a stirrer, and a cooling tube. Next, 0.005 parts by mass of a urethanization catalyst (Neostane U-28, manufactured by Nitto Kasei Co., Ltd.) and 1 part by mass of Irganox 1135 (manufactured by BASF Corporation) as an antioxidant were added, and after mixing at 40°C, a diisocyanate compound was added. Then, 1.28 parts by mass of hexamethylene diisocyanate (Duranate 50M, manufactured by Asahi Kasei Co., Ltd., indicated as "HDI" in Table 2) was added, and the mixture was reacted at 70°C. The isocyanate index was 45. The reaction generated heat, and the internal temperature reached approximately 70°C, and the viscosity also increased with time. The mixture was stirred at 70°C for 3 hours, and after confirming by FT-IR that the isocyanate groups had disappeared, it was cooled to room temperature. After cooling, 405 parts by mass of water was added and stirred for 3 hours while diluting to obtain a uniform transparent solution containing an aqueous composition containing hydroxyl-terminated urethane prepolymer (X) with an average number of hydroxyl groups of 2.4 and a solid content of 20% by mass. (also referred to as "urethane prepolymer X1") was obtained. Table 2 shows the content (% by mass) of EO units in the obtained urethane prepolymer X1, the average number of hydroxyl groups, Mw, water solubility, and the solid content (% by mass) of the obtained aqueous composition. The following production examples are also shown in Table 2.
In addition, in Table 2, the "average number of hydroxyl groups" in the oxyalkylene polymer is the mass average of the number of hydroxyl groups of the oxyalkylene polymers used when two or more types of oxyalkylene polymers are used. In addition, the "index" is the value obtained by multiplying by 100 the ratio of the number of moles of isocyanate groups of the diisocyanate compound to the total number of moles of hydroxyl groups of the oxyalkylene polymer used when producing the hydroxyl group-terminated urethane prepolymer (X) (isocyanate The "EO unit content" in the hydroxyl group-terminated urethane prepolymer (X) is the EO unit content (unit: mass %) with respect to the total amount of oxyalkylene groups in the hydroxyl group-terminated urethane prepolymer (X). . The "average number of hydroxyl groups" in the hydroxyl group-terminated urethane prepolymer (X) is the same value as the "average number of hydroxyl groups" in the oxyalkylene polymer. In Table 2, "-" indicates that the component is not blended.

[Evaluation of water solubility of urethane prepolymer]
The water solubility of the urethane prepolymer (solid content) obtained in Production Example 1 was evaluated. The water solubility of the urethane prepolymer (solid content) was evaluated based on the following criteria.
A: Dissolves in water and becomes transparent at 25°C.
D: Does not dissolve in water at 25°C, causing haze, cloudiness, or undissolved residue.

<Production Examples 2 to 9>
Aqueous compositions containing hydroxyl-terminated urethane prepolymers (X) (also referred to as "urethane prepolymers X2 to X9") were prepared in the same manner as in Production Example 1, except for changing the blending amounts (parts by mass) shown in Table 2. was manufactured. Regarding the content of EO units in the oxyalkylene polymer (mass%), the average number of hydroxyl groups in the oxyalkylene polymer, the molecular weight in terms of hydroxyl value of the oxyalkylene polymer, Mn of the oxyalkylene polymer, and the produced urethane prepolymers X2 to X9 index, content of EO units in the hydroxyl group-terminated urethane prepolymer (X) (mass%), average number of hydroxyl groups in the hydroxyl group-terminated urethane prepolymer (X), Mw of the hydroxyl group-terminated urethane prepolymer (X), hydroxyl group-terminated urethane prepolymer (X), The water solubility of the polymer (X) and the solid content (% by mass) of the obtained aqueous composition containing the hydroxyl-terminated urethane prepolymer (X) were measured, calculated, and evaluated in the same manner as in Production Example 1. However, in Table 2, "U-600" indicates "Neostan U-600 (manufactured by Nitto Kasei Co., Ltd.)" and "U-100" indicates "Neostan U-100 (manufactured by Nitto Kasei Co., Ltd.)."

<Example 1>
100 parts by mass of urethane prepolymer ), manufactured by Tosoh Corporation, isocyanate group content 18.2% by mass) 3.70 parts by mass, and temperature-sensitive catalyst (Z) (DB30, manufactured by Tosoh Corporation, diazabicycloundecene (DBU) triazole salt as a curing catalyst) , amine value 490 to 520 mgKOH/g, 25° C. viscosity 2,720 mPa·s) were uniformly mixed, and left to stand for 4 hours to defoam to obtain an aqueous adhesive composition. The resulting aqueous adhesive composition was applied onto a 38 μm thick polyester film (base film) using a knife coater to give a dry film thickness of 20 μm, and then dried at 110° C. for 10 minutes (curing). The mixture was cured to obtain an adhesive. The EO unit content with respect to the total amount of oxyalkylene groups in the obtained adhesive was 34% by mass.

<Example 2 to Example 13>
An adhesive was obtained in the same manner as in Example 1 using the amounts (parts by mass) shown in Table 3.

Table 3 shows the measurement and evaluation results of the EO unit content relative to the total amount of oxyalkylene groups in the adhesive obtained by curing the aqueous composition for an adhesive, and the pot life of the obtained adhesive.
In Table 3, "WR80-70P" indicates "Duranate WR80-70P (manufactured by Asahi Kasei Corporation, water-dispersible hexamethylene diisocyanate)". "Kat24" indicates "Borchi Kat24 (manufactured by Borchers, bismuth-based urethane curing catalyst).""U-CATSA102" is "U-CAT SA102 (manufactured by Sun-Apro, DBU 2-ethylhexanoate (octylate)"), "U-CAT 1102" is "U-CAT 1102 (manufactured by Sun-Apro, DBU)" 2-Ethylhexanoate (octylate)), manufactured by DBN. "-" indicates that the component is not included.

When measuring the maximum heat flow for each of DB30, Kat24, U-CAT SA102 and U-CAT 1102 according to the following method, DB30, U-CAT SA102 and U-CAT 1102 have a maximum heat flow in the temperature range of 30 to 90 degrees Celsius. An exothermic peak with a maximum heat flow of 1 mcal/s or more was observed in Kat24, and no exothermic peak with a maximum heat flow of 1 mcal/s or more was observed in the temperature range of 30 to 90°C.
[Measurement of maximum heat flow]
Add 100 parts by mass of polypropylene glycol with a molecular weight of about 2,000 in terms of hydroxyl value and 4,4'-diphenylmethane diisocyanate (MDI) in an amount that gives an isocyanate index of 105, and prepare DB30, Kat24, U-CAT SA102 or U-CAT. 1.16 parts by mass of 1102 are mixed to obtain a mixed solution. Regarding this liquid mixture, the maximum heat flow of DB30, Kat24, U-CAT SA102, or U-CAT 1102 was measured by differential scanning calorimetry (DSC) under the following measurement conditions.
(Measurement conditions for differential scanning calorimetry (DSC))
Measuring equipment: Seiko Instruments DSC-6100
Amount of mixed liquid to be measured: 10mg
Measurement temperature range: 0~200℃
Temperature rising/cooling rate: 10℃/min Measurement atmosphere: Nitrogen

[Evaluation of coatability]
In Examples 1 to 13, the adhesive (layer) formed on the base film was visually observed to confirm the presence of foreign matter and repellency.
The evaluation was made as A (smooth) when a uniform adhesive layer was obtained without any foreign matter or repellency, and as B (unevenness) when foreign matter or repellency was observed. The evaluation results are shown in Table 3.

[Haze evaluation]
(1) In Examples 1 to 13, a release-treated polyester film (supporting film, thickness 38 μm) was laminated onto the adhesive (layer) formed on the base film, and then placed in a hot air dryer. The adhesive layer was stored in an atmosphere at 60° C. for 5 days to complete the crosslinking reaction of the adhesive layer, thereby producing a patch (adhesive tape) having an adhesive layer. The haze (H _t ) of the adhesive layer obtained by peeling off the carrier film from the obtained patch was measured using a simultaneous color and turbidity meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., COH400).
(2) In Examples 1 to 13, the haze (H ₀ was measured.
The change in haze over time (%) was calculated according to the following formula (a). A value of haze _H0 of less than 8% indicates that the adhesive material has high transparency, and a change in haze of less than 3% indicates that there is little change over time. It shows that the quality is maintained at a high level. Table 3 shows the value of H ₀ (%) and the change in haze (%).
(H _t −H ₀ )...(a)

[Potlife]
The above coating properties and haze change values were combined and determined as follows. The determination results are shown in Table 3.
A: When the change in haze is less than 3% and the coating property is A. B: When the change in haze is less than 3% and the coating property is B. C: The variation in haze is 3%. or more and the coating property is A. D...If the change in haze is 3% or more and the coating property is B.

[Adhesive force]
The adhesive tape (adhesive tape) obtained in the same manner as in (1) in the haze evaluation above was cut into pieces of 25 mm in width and 150 mm in length, and used as samples for evaluation.
In an atmosphere with a temperature of 23°C and a humidity of 50% RH, the adhesive layer of the evaluation sample and a glass plate (float glass) were bonded together, and the evaluation sample was placed on a horizontal surface with the base film side facing up. Then, a 2.0 kg roller was moved back and forth once from the base film side to press the adhesive layer and the glass plate together. After curing for 30 minutes in an atmosphere with a temperature of 23°C and a humidity of 50% RH, it was tested using a universal tensile tester (manufactured by A&D, product name: Tensilon RTG-1310) at a peel angle of 180° and a tensile speed of 300 mm. /min, the interface between the adhesive layer and the glass plate of the test sample was peeled off, and the adhesive force of the adhesive layer was measured. Table 3 shows the actual measured values and the evaluation results based on the following criteria.
A: When the adhesive force is 0.10N/25mm or less D: When the adhesive force exceeds 0.10N/25mm

As shown in Table 2, in Production Examples 1 to 7 and 9, excellent results were obtained in the water solubility of the solid content of the aqueous composition for adhesives.
As shown in Table 3, in Examples 1 to 7 and 10 to 13, the aqueous adhesive compositions had excellent coating properties, the initial transparency of the adhesive was high, the haze change was small, and the adhesive composition The results showed that the pot life was good. Moreover, the adhesive strength was also good.
On the other hand, in Examples 8 and 9, excellent results were not obtained in the coating properties of the water-based adhesive compositions, and although the adhesive strength of the adhesive was good, the initial transparency was low and the haze was low. The results showed that the change was large and the pot life was poor.

The adhesive obtained by the present invention can be used in flat panel displays (liquid crystal displays, organic electroluminescent displays, etc.) and touch panel displays, which are widely used in electronic devices such as televisions, personal computers (PCs), mobile phones, and mobile terminals; , for surface protection films that protect the surfaces of substrates manufactured or used in these manufacturing processes (glass substrates, ITO/glass substrates with an ITO (indium tin oxide) film formed on the glass substrate, etc.) and optical components. It is suitably used as a pressure-sensitive adhesive.

Claims (15)

A hydroxyl-terminated urethane obtained by subjecting an oxyalkylene polymer (A) having an oxyethylene group and an average number of hydroxyl groups per molecule of 1.6 or more and 8.0 or less and a diisocyanate compound (B) to form a urethane. An aqueous composition for an adhesive comprising a prepolymer (X), a polyisocyanate compound (Y), and a temperature-sensitive catalyst (Z),
An aqueous composition for an adhesive, wherein the content of oxyethylene groups based on the total amount of oxyalkylene groups in the hydroxyl-terminated urethane prepolymer (X) is 15% by mass or more and 90% by mass or less. The aqueous composition for pressure-sensitive adhesives according to claim 1, wherein the temperature-sensitive catalyst (Z) is at least one selected from the group consisting of a piperazine-based amine catalyst, a morpholine-based amine catalyst, and a diazabicyclo compound-based catalyst. . The aqueous composition for an adhesive according to claim 1, wherein the polyisocyanate compound (Y) is a water-dispersible polyisocyanate compound. The aqueous composition for an adhesive according to claim 3, wherein the water-dispersible polyisocyanate compound is at least one selected from the group consisting of aliphatic polyisocyanates and alicyclic polyisocyanates. The hydroxyl group-terminated urethane prepolymer (X) is obtained by subjecting the oxyalkylene polymer (A) and the diisocyanate compound (B) to a urethanization reaction in the presence of a hydrolyzable catalyst (C). The aqueous composition for adhesives according to claim 1. The hydrolyzable catalyst (C) is selected from the group consisting of Sn(II), Ca(II), Mn(II), Zn(II), Co(II), Pb(II) and Bi(III). The aqueous composition for an adhesive according to claim 5, which is a catalyst containing at least one metal. The aqueous composition for an adhesive according to claim 1, wherein the weight average molecular weight of the hydroxyl-terminated urethane prepolymer (X) is 15,000 or more and 100,000 or less. The aqueous composition for an adhesive according to claim 1, wherein the oxyalkylene polymer (A) has a molecular weight in terms of hydroxyl value of 1,000 or more and 50,000 or less. The aqueous composition for an adhesive according to claim 1, wherein the ratio of oxyethylene groups to the total amount of oxyalkylene groups in the oxyalkylene polymer (A) is 15% by mass or more. The oxyalkylene polymer (A) is an oxyalkylene polymer (A1) having an average number of hydroxyl groups per molecule of more than 2.0 and 8.0 or less, and an oxyalkylene polymer (A1) having an average number of hydroxyl groups per molecule of 1.6 or more and 2 or more. The aqueous composition for an adhesive according to claim 1, comprising an oxyalkylene polymer (A2) having a molecular weight of . The mass ratio of the oxyalkylene polymer (A1) to the oxyalkylene polymer (A2) is such that oxyalkylene polymer (A1)/oxyalkylene polymer (A2) is more than 0.0 and not more than 4.0. , the aqueous composition for adhesives according to claim 10. An adhesive obtained by curing the aqueous adhesive composition according to any one of claims 1 to 11. An adhesive patch comprising a base material and an adhesive layer comprising the adhesive according to claim 12 provided on at least one surface of the base material. An adhesive tape comprising a base material and an adhesive layer comprising the adhesive according to claim 12 provided on at least one surface of the base material. A method for producing an adhesive, comprising producing an adhesive using the aqueous composition for an adhesive according to any one of claims 1 to 11,
An aqueous composition for an adhesive containing the hydroxyl-terminated urethane prepolymer (X), the polyisocyanate compound (Y), and the temperature-sensitive catalyst (Z) is prepared, and the aqueous composition for an adhesive is used as a base. heating the base material coated with the aqueous adhesive composition;
Preparing the aqueous adhesive composition at a temperature lower than the exothermic peak temperature of the temperature-sensitive catalyst (Z),
A method for producing an adhesive, wherein the heating is performed at a temperature higher than the exothermic peak temperature of the temperature-sensitive catalyst (Z).