JP2012111786A - Adhesive material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an adhesive material which has excellent removability and good heat resistance, and of which the removability is less likely to be reduced over time at higher temperatures.SOLUTION: The adhesive material is obtained by curing a curable composition containing a silyl-group-containing polymer (S) which has a constituent unit derived from an initiator (a) that has at least two active hydrogen groups per molecule, a constituent unit derived from an anhydrous dicarboxylic acid (b), and a constituent unit derived from an alkylene oxide (c), and which also has a hydrolyzable silyl group at the terminal of the molecule thereof.

Description

  The present invention relates to a pressure-sensitive adhesive body, a silyl group-containing polymer used for the pressure-sensitive adhesive body, and a method for producing a pressure-sensitive adhesive sheet.

  The adhesive is required to be difficult to peel off the adherend and the adhesive layer bonded through the adhesive layer. On the other hand, the pressure-sensitive adhesive is used as a curable composition for forming a tape-like pressure-sensitive adhesive body cured on the base material, and has good adhesion between the base material and the pressure-sensitive adhesive body, and at the same time, the pressure-sensitive adhesive body after curing. After adhering the adherend to the substrate, re-peelability is required so that the adhesive can be peeled off from the adherend so that there is no adhesive residue. That is, the adhesive is required to be permanently bonded by the adhesive layer, whereas the pressure-sensitive adhesive is required to exhibit both adhesiveness at the time of curing and removability of the pressure-sensitive adhesive after curing. Therefore, the adhesive and the pressure-sensitive adhesive are similar but have different required characteristics.

In recent years, when manufacturing electrical parts, electronic materials, and the like, protective sheets and protective tapes are frequently used. This is to protect these parts and materials from scratches and dust in processes such as storage and transportation. Particularly in the manufacture of electronic parts and optical members, it is necessary to thoroughly eliminate the attachment of minute dust to products being manufactured. This is because dust causes contamination and causes product defects. As this protective sheet or protective tape, an adhesive sheet or adhesive tape having an adhesive layer having low adhesive strength is employed.
As conventional adhesives, acrylic adhesives, rubber adhesives, silicone adhesives, urethane adhesives (for example, Patent Document 1), and oxyalkylene adhesives (for example, Patent Documents 2 and 3) are known. Yes.

JP 2003-12751 A International Publication No. 2005/73333 Pamphlet International Publication No. 2005/73334 Pamphlet

A conventional pressure-sensitive adhesive such as an acrylic type has a problem that the adhesive strength increases with time and re-peelability tends to decrease. In particular, the adhesive strength tends to increase at high temperatures.
Also, when trying to produce an adhesive with low adhesive strength, even if the composition of the adhesive is adjusted so that the initial adhesive strength is low, the adhesive strength increases if the sticking time is long. was there. If the adhesive force increases, the adherend may be deformed or damaged. Conversely, when the composition of the pressure-sensitive adhesive is adjusted so that the pressure-sensitive adhesive strength is lowered after a certain time, there has been a problem that sufficient pressure-sensitive adhesive strength cannot be obtained in the first place. If sufficient adhesive strength is not obtained, it peels off unintentionally from the adherend and cannot fulfill a predetermined role such as a protective sheet. In addition, the thickness of the pressure-sensitive adhesive layer may be reduced to suppress an increase in adhesive force. However, in this case, the original function of the pressure-sensitive adhesive, i.e., adhesion to the adherend with light pressure, tends to be impaired.

  The present invention has been made in view of the above circumstances, has a removability, has good heat resistance, and does not easily deteriorate even after a long time at high temperatures, and has a low adhesive strength. An object of the present invention is to provide a silyl group-containing polymer used for the pressure-sensitive adhesive body and a method for producing a pressure-sensitive adhesive sheet.

  In order to solve the above-mentioned problems, the pressure-sensitive adhesive body of the present invention is composed of a structural unit derived from an initiator (a) having two or more active hydrogen groups per molecule and a structure derived from a dicarboxylic acid anhydride (b). It is obtained by curing a curable composition containing a silyl group-containing polymer (S) having a unit and a structural unit derived from an alkylene oxide (c) and having a hydrolyzable silyl group at the molecular end. And

The silyl group-containing polymer (S) is obtained by subjecting an initiator (a) having two or more active hydrogen groups per molecule to ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c). A silyl group-containing polymer (S1) obtained by introducing a hydrolyzable silyl group into the molecular terminal of the polyester ether polyol (Z);
A polyester ether polyol (Z) is obtained by ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c) to an initiator (a) having two or more active hydrogen groups per molecule, and the polyester ether polyol A polyol (A) containing (Z) and a polyisocyanate compound (B) are reacted to obtain a prepolymer (P), which is obtained by introducing a hydrolyzable silyl group into the molecular terminal of the prepolymer (P). A silyl group-containing polymer (S2); or a polyester ether obtained by subjecting an initiator (a) having two or more active hydrogen groups per molecule to ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c). A polyol (Z) is obtained, and a polyol (A) containing the polyester ether polyol (Z) is reacted with a polyisocyanate compound (B) to form a polyol. It is obtained by obtaining a repolymer (P), reacting the prepolymer (P) with a chain extender (C) to obtain a chain-extended polyurethane, and introducing a hydrolyzable silyl group into the molecular end of the chain-extended polyurethane. A silyl group-containing polymer (S3) is preferred.

  The present invention is also derived from a structural unit derived from an initiator (a) having two or more active hydrogen groups per molecule, a structural unit derived from a dicarboxylic acid anhydride (b), and an alkylene oxide (c). And a silyl group-containing polymer (S) having a hydrolyzable silyl group at the molecular end.

  The present invention also includes a step of forming an uncured layer comprising a curable composition containing the silyl group-containing polymer (S) of the present invention on a substrate, and the opposite side of the uncured layer from the substrate. There is provided a method for producing a pressure-sensitive adhesive sheet comprising a step of curing the uncured layer in a state where the surface is exposed or a state where a release sheet is laminated on the surface.

According to the present invention, it is possible to realize a pressure-sensitive adhesive body having removability, having good heat resistance and being less likely to be re-removable even when time passes at high temperatures, and having low adhesive strength.
According to the present invention, it is possible to realize a pressure-sensitive adhesive sheet that has removability, has good heat resistance, and does not easily decrease removability even when time passes at high temperatures, and has low adhesive strength.
Moreover, the silyl group containing polymer (S) of this invention is suitable as a hardening component of the curable composition used as the adhesive body of this invention after hardening.

It is a graph which shows the temperature dependence of the vibrational absorption characteristic of the adhesive body obtained in the Example of this invention.

The number average molecular weight (Mn) and the mass average molecular weight (Mw) in this specification are polystyrene-converted molecular weights obtained by measuring with gel permeation chromatography using a standard curve prepared using a standard polystyrene sample with a known molecular weight. It is. The molecular weight distribution (Mw / Mn) is a value obtained by dividing the mass average molecular weight (Mw) by the number average molecular weight (Mn).
The average hydroxyl value (OHV) in this specification is a measured value based on JIS-K-1557-6.4.
In this specification, the polyester ether polyol is a polyol having an ester bond and an ether bond.

In the present specification, the adhesion property is a property that adheres to an adherend with light pressure and can be re-peeled arbitrarily. An adhesive substance is an adhesive compact.
In the present specification, the adhesiveness may be classified according to the peeling adhesive strength (peeling strength from the adherend). Slight adhesion when peel adhesion exceeds 0 N / 25 mm and less than 1 N / 25 mm, low adhesion when peel adhesion exceeds 1 N / 25 mm and less than 8 N / 25 mm, and peel adhesion exceeds 8 N / 25 mm and 15 N / 25 mm The following cases are referred to as medium adhesion, and the case where the peel adhesive strength exceeds 15 N / 25 mm and is 50 N / 25 mm or less is called strong adhesion.
Unless otherwise specified, the peel adhesive strength conforms to the 180-degree peeling method specified in JIS-Z-0237 (1999) -8.3.1 and follows the following test method.
That is, in a 23 ° C. environment, a 1.5 mm thick bright annealed stainless steel plate (SUS304 (JIS)) was attached to a pressure sensitive adhesive sheet test piece (width: 25 mm), and a rubber roll having a mass of 2 kg. Crimp. After 30 minutes, the peel strength (180 degree peel, tensile speed 300 mm / min) is measured using a tensile tester specified in JIS-B-7721. The value of the peel strength after 30 minutes of sticking obtained in this way is defined as “peel adhesive strength” in the present invention.

The pressure-sensitive adhesive body of the present invention is obtained by curing a curable composition containing a silyl group-containing polymer (S).
<Silyl group-containing polymer (S)>
The silyl group-containing polymer (S) includes a structural unit derived from an initiator (a) having two or more active hydrogen groups per molecule, a structural unit derived from a dicarboxylic acid anhydride (b), and an alkylene oxide. It has a structural unit derived from (c) and has a hydrolyzable silyl group at the molecular end.
The silyl group-containing polymer (S) is cured by reacting with moisture, and the cured product has removability. Therefore, the silyl group-containing polymer (S) is suitable for use as an adhesive.
(1) The silyl group-containing polymer (S1) of the first embodiment is prepared by adding a dicarboxylic acid anhydride (b) and an alkylene oxide (c) to an initiator (a) having two or more active hydrogen groups per molecule. It is obtained by introducing a hydrolyzable silyl group into the molecular terminal of the polyester ether polyol (Z) obtained by ring-opening polymerization.
(2) The silyl group-containing polymer (S2) of the second embodiment is prepared by reacting the polyol (A) containing the polyester ether polyol (Z) with the polyisocyanate compound (B) to produce a prepolymer (P). And a hydrolyzable silyl group is introduced at the molecular end of the prepolymer.
(3) The silyl group-containing polymer (S3) of the third embodiment is obtained by reacting the prepolymer (P) with a chain extender (C) to obtain a chain extended polyurethane, and a molecular end of the chain extended polyurethane. It is obtained by introducing a hydrolyzable silyl group.
The silyl group-containing polymer (S) in the present specification is a concept including the silyl group-containing polymers (S1) to (S3) of the first to third embodiments.

<First Embodiment>
[Initiator (a)]
The initiator (a) is a compound having two or more active hydrogen groups per molecule, and examples thereof include polyether polyols and polyhydric alcohols. The number of active hydrogen groups per molecule of the initiator (a) is preferably 2 to 4, more preferably 2 or 3. That is, as the initiator (a), polyhydric alcohols may be used as they are, and further, alkylene oxide may be added and used as a polyether polyol. The active hydrogen group in the initiator (a) is particularly preferably a hydroxyl group.
In the present invention, the structural unit derived from the initiator (a) means the remaining group obtained by removing all active hydrogen groups from the initiator (a).

The polyether polyol is a compound having a molecular weight of 300 to 4000 per hydroxyl group, which is obtained by adding an alkylene oxide to a polyhydric alcohol. When a double metal cyanide complex catalyst is used as a catalyst during the production of the polyester ether polyol (Z) described later, it is preferable to use a polyether diol as the initiator (a).
Examples of the polyhydric alcohols include ethylene glycol, diethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, and glycerin.
The alkylene oxide is preferably an alkylene oxide having 2 to 4 carbon atoms, and examples thereof include propylene oxide, 1,2-butylene oxide, 2,3-butylene oxide, and ethylene oxide. Alkylene oxide may use only 1 type, or may use 2 or more types together. The alkylene oxide is preferably ethylene oxide or propylene oxide, and more preferably only propylene oxide.

  The molecular weight of the initiator (a) is preferably 62 to 4000, and more preferably 400 to 2000. If the molecular weight is 62 or more, good flexibility can be obtained in the resulting adhesive. Moreover, if the said molecular weight is 4000 or less, it is preferable when improving the cohesion force of the adhesive body obtained.

  In the polyester ether polyol (Z), the constituent unit derived from the initiator (a) is preferably contained in an amount of 1 to 60% by mass, more preferably 10 to 60% by mass. If the content of the structural unit derived from the initiator (a) is 1% by mass or more, the polyester ether polyol (Z) is easily obtained efficiently. Moreover, if content of the structural unit derived from an initiator (a) is 60 mass% or less, since content of dicarboxylic acid anhydride (b) in polyester ether polyol (Z) can be increased, the adhesive which is obtained The cohesive strength of is improved.

[Dicarboxylic anhydride (b)]
Examples of the dicarboxylic acid anhydride (b) include phthalic anhydride, maleic anhydride, and succinic anhydride. In particular, aromatic dicarboxylic acid anhydrides are preferable in that they have a high cohesion and polarity, and thus contribute greatly to the adhesion to the substrate and the adhesion to the adherend. Specifically, phthalic anhydride is more preferable.
In the polyester ether polyol (Z), the structural unit derived from the dicarboxylic acid anhydride (b) is preferably contained in an amount of 10 to 50% by mass, and more preferably 15 to 40% by mass. When the content of the structural unit derived from the dicarboxylic acid anhydride (b) is 10% by mass or more, an adhesive body excellent in adhesiveness is obtained. Moreover, if content of the structural unit derived from dicarboxylic acid anhydride (b) is 50 mass% or less, the adhesive body excellent in the softness | flexibility will be obtained.

[Alkylene oxide (c)]
Examples of the alkylene oxide (c) include the same alkylene oxides used for the synthesis of the polyether polyol as the initiator (a). Among these, it is more preferable to use propylene oxide or ethylene oxide.

  The molar ratio of the alkylene oxide (c) and the dicarboxylic acid anhydride (b) used for the synthesis of the polyester ether polyol (Z) is [the amount of the alkylene oxide (c) (mol)] / [dicarboxylic acid anhydride (b). ) Of the substance (mol)] = 50/50 to 95/5, more preferably 50/50 to 80/20. When the molar ratio of the alkylene oxide (c) to the dicarboxylic acid anhydride (b) is 50/50 or more, the alkylene oxide (c) becomes excessive with respect to the dicarboxylic acid anhydride (b), and the alkylene oxide is terminated at the terminal. While (c) is added in blocks, the amount of unreacted dicarboxylic acid anhydride (b) in the polyester ether polyol (Z) can be suppressed, so that the acid value of the polyester ether polyol (Z) can be lowered. Moreover, if this molar ratio is below the said upper limit, the cohesion force of the adhesive body obtained will improve.

In the copolymer chain of polyester ether polyol (Z) (part where dicarboxylic acid anhydride (b) and alkylene oxide (c) are copolymerized), dicarboxylic acid anhydride (b) and alkylene oxide (c) alternate. Or an alkylene oxide (c) undergoes a block addition reaction. However, in dicarboxylic acid anhydride (b) and alkylene oxide (c), dicarboxylic acid anhydride (b) is more reactive and dicarboxylic acid anhydride (c) does not undergo an addition reaction continuously. The number of alkylene oxides (c) constituting the block chain in the polymer chain is as short as several. Therefore, the entire structure of the polyester ether polyol (Z) can be designed by adjusting the molecular weight of the initiator (a) and the addition amount of the alkylene oxide (c) at the terminal portion.
In particular, when polyhydric alcohols are used as the initiator (a), when the polyester ether polyol (Z) is produced, the alkylene oxide (c) is used in excess of the dicarboxylic acid anhydride (b), and the dicarboxylic acid is used. It is preferable to reduce the remaining amount of the unreacted acid anhydride (b) from the viewpoint of improving the reactivity between the molecular terminal of the polyester ether polyol (Z) and the isocyanate group.

[catalyst]
In the production of the polyester ether polyol (Z), it is preferable to use a catalyst from the viewpoint of a high polymerization reaction rate.
As the catalyst, a ring-opening addition polymerization catalyst is suitably used, and examples thereof include alkali catalysts such as potassium hydroxide and cesium hydroxide; double metal cyanide complex catalysts; phosphazene catalysts. Especially, since the polyester ether polyol (Z) with a smaller value of Mw / Mn is obtained, a double metal cyanide complex catalyst is more preferable.
As the double metal cyanide complex catalyst, a zinc hexacyanocobaltate complex coordinated with an organic ligand is preferable. As the organic ligand, ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, and alcohols such as tert-butyl alcohol are preferable.

[Polyester ether polyol (Z)]
The polyester ether polyol (Z) preferably has a hydroxyl value converted molecular weight per hydroxyl group of 250 to 20,000, more preferably 1000 to 10,000, and even more preferably 1,000 to 5,000. When the molecular weight in terms of hydroxyl value is 250 or more, the flexibility of the obtained pressure-sensitive adhesive is improved. If the molecular weight in terms of hydroxyl value is 20,000 or less, the cohesive force of the resulting pressure-sensitive adhesive is improved, and the viscosity of the solution tends to be low when the silyl group-containing polymer (S) is dissolved in a solvent.
The molecular weight in terms of hydroxyl value of the polyester ether polyol (Z) can be easily adjusted by appropriately adjusting the number of moles of the dicarboxylic acid anhydride (b) and the alkylene oxide (c) copolymerized with the initiator (a).

The polyester ether polyol (Z) preferably has an average molecular weight (M ′) per copolymer chain of 100 to 3000, more preferably 200 to 2000. The average molecular weight (M ′) per copolymer chain means the average molecular weight per copolymer chain formed by copolymerization of dicarboxylic anhydride (b) and alkylene oxide (c). This is a value obtained by removing the molecular weight of the initiator (a) from the molecular weight in terms of hydroxyl value and dividing the molecular weight by the number of functional groups (number of active hydrogen groups) of the initiator (a).
When the average molecular weight (M ′) per copolymer chain is 100 or more, the flexibility of the obtained pressure-sensitive adhesive is easily improved. Further, when the average molecular weight (M ′) per copolymer chain is 3000 or less, the viscosity of the resulting polyester ether polyol (Z) does not become too high. The average molecular weight (M ′) per copolymer chain is appropriately determined by the number of moles of the dicarboxylic acid anhydride (b) and alkylene oxide (c) copolymerized with the initiator (a) as in the case of the hydroxyl value converted molecular weight. It can be easily adjusted by adjusting.

  The acid value of the polyester ether polyol (Z) is preferably 2.0 mgKOH / g or less, more preferably 1.0 mgKOH / g or less, and may be zero. If the acid value of the polyester ether polyol (Z) is 2.0 mgKOH / g or less, the reactivity between the molecular terminal of the polyester ether polyol (Z) and the isocyanate group is improved, and the storage stability of the resulting pressure-sensitive adhesive is improved. improves.

[Silyl group-containing polymer (S1)]
The silyl group-containing polymer (S1) of this embodiment is obtained by introducing a hydrolyzable silyl group into the molecular terminal of the polyester ether polyol (Z) by the method described later.

<Second Embodiment>
In this embodiment, a polyol (A) containing a polyester ether polyol (Z) and a polyisocyanate compound (B) are reacted to obtain a prepolymer (P), and hydrolysis is performed at the molecular terminals of the prepolymer (P). A functional silyl group is introduced.
The polyester ether polyol (Z) is the same as that of the first embodiment including the preferred mode.

[Polyol (A)]
The ratio of the polyester ether polyol (Z) in the polyol (A) is preferably 10% by mass or more and more preferably 50% by mass or more in order to increase the flexibility of the pressure-sensitive adhesive and prevent the removability from being lowered. Preferably, all of the polyol (A) is most preferably a polyester ether polyol (Z).
The polyester ether polyol (Z) may be one type or a combination of two or more types.

  When a part of the polyol (A) is a polyester ether polyol (Z), any one of polyoxytetramethylene polyol, polyoxyalkylene polyol, polyester polyol, and polycarbonate polyol is used as the balance of the polyol (A) or Two or more kinds of polyols (other polyols) are preferably used.

[Polyisocyanate compound (B)]
Examples of the polyisocyanate compound (B) include naphthalene-1,5-diisocyanate, polyphenylene polymethylene polyisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate (hereinafter referred to as 2,4-TDI). And aromatic polyisocyanates such as 2,6-tolylene diisocyanate (hereinafter sometimes referred to as 2,6-TDI); aralkyls such as xylylene diisocyanate and tetramethylxylylene diisocyanate Polyisocyanate; aliphatic polyisocyanate such as hexamethylene diisocyanate (hereinafter referred to as HDI); isophorone diisocyanate (hereinafter referred to as IPDI) and 4,4′-methylenebis (cyclohexyl isocyanate) Alicyclic polyisocyanates over G) or the like; and urethane modified product obtained from the polyisocyanate, biuret modified compounds, allophanate modified body, carbodiimide modified body, and isocyanurate-modified products thereof.
Among these, as the polyisocyanate compound (B), those having two isocyanate groups are preferable, and 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate are particularly preferable.

  Moreover, when using the adhesive body of this invention for an optical use, it is preferable to use a non-yellowing polyisocyanate as a polyisocyanate compound (B). For example, aliphatic polyisocyanates such as hexamethylene diisocyanate, 2,2,4-trimethyl-hexamethylene diisocyanate, 2,4,4-trimethyl-hexamethylene diisocyanate; alicyclic rings such as isophorone diisocyanate and methylenebis (4-cyclohexylisocyanate) Formula polyisocyanate; non-yellowing aromatic diisocyanate such as xylylene diisocyanate.

[Prepolymer (P)]
In this embodiment, the prepolymer (P) may be an isocyanate group-terminated prepolymer (PI) having an isocyanate group at the end of the molecular chain, or a hydroxyl-terminated prepolymer (PH) having a hydroxyl group at the end of the molecular chain.

[Isocyanate group-terminated prepolymer (PI)]
The isocyanate group-terminated prepolymer (PI) is obtained by reacting the polyol (A) with the polyisocyanate compound (B) in an excess ratio of isocyanate groups (hereinafter, this reaction is referred to as prepolymer formation reaction).
Specific examples of the prepolymer formation reaction include a reaction in which the polyol (A) and the polyisocyanate compound (B) are heated at 60 to 100 ° C. for 1 to 20 hours in a dry nitrogen stream. In the prepolymer forming reaction, a urethanization reaction catalyst can be used.
Examples of the urethanization reaction catalyst include organic tin compounds such as dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin dioctoate, and tin 2-ethylhexanoate; iron compounds such as iron acetylacetonate and ferric chloride; And tertiary amine catalysts such as triethylamine and triethylenediamine. Of the urethanization reaction catalysts, organotin compounds are preferred.

  Further, in the prepolymer forming reaction, it may be diluted with a solvent. Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, esters such as ethyl acetate and butyl acetate, ketones such as methyl ethyl ketone (hereinafter referred to as MEK), and dimethylformamide. And cyclohexanone. These may be used alone or in combination of two or more.

The ratio of the polyol (A) and the polyisocyanate compound (B) in the prepolymer formation reaction is defined as a value 100 times the molar ratio of “isocyanate group of the polyisocyanate compound (B) / hydroxyl group of the polyol (A)”. The isocyanate index is preferably more than 100 to 200, more preferably 105 to 170. The isocyanate group-terminated prepolymer (PI) obtained by the prepolymer formation reaction has an isocyanate group content of 1.5 to 10.0 mass. % Is preferred.
The molecular weight of the isocyanate group-terminated prepolymer (PI) is preferably a number average molecular weight (Mn) of 2000 to 150,000, and more preferably 3000 to 80,000.

[Hydroxyl-terminated prepolymer (PH)]
The hydroxyl group-terminated prepolymer (PH) is obtained by reacting the polyol (A) with the polyisocyanate compound (B) at a ratio of excess hydroxyl group.
The reaction between the polyol (A) and the polyisocyanate compound (B) can be carried out in the same manner as the prepolymer formation reaction for obtaining the isocyanate group-terminated prepolymer (PI).
That is, in the step of performing the prepolymer formation reaction, the ratio of the polyol (A) and the isocyanate compound (B) is preferably 50 to less than 100 and more preferably 50 to 98.

In the step of producing the hydroxyl group-terminated prepolymer (PH), a urethanization reaction catalyst similar to the prepolymer formation reaction for obtaining the isocyanate group-terminated prepolymer (PI) may be used. Moreover, you may dilute with the solvent similar to the prepolymer formation reaction for obtaining isocyanate group terminal prepolymer (PI).
The hydroxyl group content in the hydroxyl group-terminated prepolymer (PH) thus obtained is 0.03 to 1.00% by mass. It is preferable that
The molecular weight of the hydroxyl group-terminated prepolymer (PH) is preferably 2000 to 100,000, more preferably 3000 to 80,000 in terms of number average molecular weight (Mn).

[Silyl group-containing polymer (S2)]
The silyl group-containing polymer (S2) of this embodiment is obtained by introducing a hydrolyzable silyl group into the molecular terminal of the isocyanate group-terminated prepolymer (PI) or the hydroxyl group-terminated prepolymer (PH) by the method described later. It is done.

<Third Embodiment>
In this embodiment, the polyol (A) containing the polyester ether polyol (Z) and the polyisocyanate compound (B) are reacted to obtain a prepolymer (P), and a chain extender is added to the isocyanate group-terminated prepolymer (P). (C) is reacted to obtain a chain-extended polyurethane, and a hydrolyzable silyl group is introduced into the molecular end of the chain-extended polyurethane.
The polyester ether polyol (Z), polyol (A), polyisocyanate compound (B), and prepolymer (P) are the same as in the second embodiment, including preferred aspects.

[Chain extender (C)]
When the isocyanate group-terminated prepolymer (PI) is used as the prepolymer (P), low-molecular diols and low-molecular diamines are preferable as the chain extender.
Preferred examples of the low molecular diols include ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like.
Low molecular diamines include aliphatic diamines such as ethylenediamine, propylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, 2,2,4-trimethylhexamethylenediamine; piperazine, isophoronediamine, dicyclohexyl And alicyclic diamines such as methane-4,4′-diamine; and aromatic diamines such as tolylenediamine, phenylenediamine, and xylylenediamine.

  When using a hydroxyl-terminated prepolymer (PH) as the prepolymer (P), a diisocyanate compound is preferred as the chain extender. A preferred diisocyanate compound is the same as the polyisocyanate compound (B) having two isocyanate groups.

[Chain extension reaction]
The chain extension polyurethane according to the present invention is obtained by subjecting the prepolymer (P) to a chain extension reaction. The end of the chain extended polyurethane may be any of an isocyanate group, a hydroxyl group, or an amino group. The method for introducing a hydrolyzable silyl group differs depending on the terminal group.

The method of chain extension reaction is not particularly limited. For example, 1) A method in which a prepolymer (P) solution is charged into a reaction vessel and a chain extender (C) is dropped into the reaction vessel to cause a reaction, and 2) a chain extender. A method in which (C) is charged into a reaction vessel and the prepolymer (P) solution is dropped and reacted. 3) After diluting the prepolymer (P) solution with a solvent, a chain extender (C) is placed in the reaction vessel. There is a method in which a fixed amount is added and reacted. The method 1) or 3) is preferable because it is easy to obtain a uniform chain-extended polyurethane.
As the solvent, the same solvents as those exemplified in the prepolymer formation reaction can be used.

When the isocyanate group-terminated prepolymer (PI) is reacted with a low molecular diamine as a chain extender, the ratio of the prepolymer (PI) and the low molecular diamine is “NCO group / low molecule of the prepolymer (PI)”. preferably the isocyanate index defined by 100 times the molar ratio of NH ₂ groups "of diamines is less than 50 to 100, 50 to 98 is more preferable. Within this range, an amino group-terminated chain-extended polyurethane can be obtained.
When a hydroxyl group-terminated prepolymer (PH) is reacted with a diisocyanate compound as a chain extender to obtain an isocyanate group-terminated chain-extended polyurethane, the ratio of the prepolymer (PH) and the diisocyanate compound is expressed as “NCO of chain extender”. The isocyanate index defined by a value 100 times the molar ratio of “group / OH group of prepolymer (PH)” is preferably more than 100 to 200, more preferably 101 to 150.
When the hydroxyl-terminated prepolymer (PH) is reacted with a diisocyanate compound to obtain a chain-extended polyurethane having a hydroxyl terminal, the isocyanate index is preferably 50 to less than 100, more preferably 50 to 98.

The reaction temperature in the chain extension reaction is preferably 80 ° C. or lower. When the reaction temperature exceeds 80 ° C., the reaction rate becomes too fast and it becomes difficult to control the reaction, so that it tends to be difficult to obtain a chain-extended polyurethane having a desired molecular weight and a desired structure. When the chain extension reaction is performed in the presence of a solvent, the reaction temperature is preferably set to be equal to or lower than the boiling point of the solvent. In particular, 40-60 ° C. is preferred in the presence of MEK and / or ethyl acetate.
The molecular weight of the chain extended polyurethane is preferably 4,000 to 500,000 in terms of number average molecular weight. More preferably, it is 8,000-250,000.

[Silyl group-containing polymer (S3)]
The silyl group-containing polymer (S3) of the present embodiment is obtained by introducing a hydrolyzable silyl group into the molecular end of the chain-extended polyurethane by the method described later.

<Hydrolyzable silyl group>
In the present invention, the hydrolyzable silyl group is a silyl group having a hydrolyzable group. Specifically, a silyl group represented by -SiX _a R ³ _(3-a) is preferable. Here, a represents an integer of 1 to 3. a is preferably 2 to 3, and 3 is most preferable.
R ³ is a monovalent organic group having 1 to 20 carbon atoms, preferably a monovalent organic group having 1 to 6 carbon atoms. Specific examples include methyl group, ethyl group, propyl group, butyl group, pentyl group and the like. R ³ may have a substituent. Examples of the substituent include a methyl group and a phenyl group.
If the hydrolyzable silyl group has a plurality of R ^3, R ³ of the plurality of it may be the same or different from each other. That is, when a is 1, two R ³ bonded to one silicon atom (Si) are each independently a monovalent monovalent group having 1 to 20 carbon atoms that may have a substituent. An organic group is shown.

X represents a hydroxyl group (—OH) or a hydrolyzable group. Examples of the hydrolyzable group include -OR group (R is a hydrocarbon group having 4 or less carbon atoms). Such —OR group is preferably an alkoxy group or an alkenyloxy group, and particularly preferably an alkoxy group. The alkoxy group or alkenyloxy group has 4 or less carbon atoms. Specific examples include a methoxy group, an ethoxy group, a propoxy group, and a propenyloxy group. Among these, a methoxy group or an ethoxy group is more preferable in that the curing rate of the curable composition can be further increased.
When a plurality of X are present in the hydrolyzable silyl group, the plurality of X may be the same as or different from each other. That is, when a is 2 or 3, each X independently represents a hydroxyl group or a hydrolyzable group.
As the hydrolyzable silyl group, a trialkoxysilyl group is preferable, a trimethoxysilyl group or a triethoxysilyl group is more preferable, and a trimethoxysilyl group is particularly preferable. This is because the storage stability of the silyl group-containing polymer (S) is good and the curing rate of the curable composition is fast.

<Introduction of hydrolyzable silyl group>
As a method for introducing a hydrolyzable silyl group, a method using an isocyanate silane (Q1), a method using an aminosilane (Q2), a method using a mercaptosilane (Q3), a method using an epoxysilane (Q4), And a method (Q5) using hydrosilanes.
The ratio of introducing a hydrolyzable silyl group (hereinafter sometimes referred to as a hydrolyzable silyl group introduction ratio) is 50 to 100 mol%, assuming that all the terminals capable of reacting theoretically are 100 mol%. It is preferable to introduce, more preferably 80 to 100 mol%.

<Method (Q1) using isocyanate silanes>
When the terminal functional group of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with the hydrolyzable silyl group is a group capable of reacting with an isocyanate group, the terminal functional group A hydrolyzable silyl group can be introduced by reacting silane with isocyanate silanes.
The group capable of reacting with an isocyanate group is, for example, a hydroxyl group or an amino group.

Isocyanate silanes include isocyanate methyltrimethoxysilane, 2-isocyanatoethyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, 4-isocyanatobutyltrimethoxysilane, 5-isocyanatepentyltrimethoxysilane, isocyanatemethyltriethoxysilane, 2-isocyanatoethyltriethoxysilane, 3-isocyanatopropyltriethoxysilane, 4-isocyanatobutyltriethoxysilane, 5-isocyanatepentyltriethoxysilane, isocyanatemethylmethyldimethoxysilane, 2-isocyanatoethylethyldimethoxysilane, 3-isocyanatopropyl Examples include trimethoxysilane or 3-isocyanatopropyltriethoxysilane. That.
Among these, isocyanate methyltrimethoxysilane, 3-isocyanatopropyltrimethoxysilane, or 3-isocyanatopropyltriethoxysilane is preferable.

  A catalyst may be used for this reaction. A known urethanization reaction catalyst is used as the catalyst. Examples thereof include organic acid salts / organometallic compounds, tertiary amines and the like. Specific examples of organic acid salts and organometallic compounds include tin catalysts such as dibutyltin dilaurate (DBTDL), bismuth catalysts such as bismuth 2-ethylhexanoate [bismuth tris (2-ethylhexanoate)], zinc naphthenate Examples thereof include zinc catalysts such as cobalt catalysts such as cobalt naphthenate and copper catalysts such as copper 2-ethylhexanoate. Tertiary amines include triethylamine, triethylenediamine, N-methylmorpholine and the like.

<Method (Q2) using aminosilanes>
When the terminal functional group of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with a hydrolyzable silyl group is a group capable of reacting with an amino group, the terminal functional group A hydrolyzable silyl group can be introduced by reacting silane with aminosilanes.

Examples of the group capable of reacting with an amino group are an isocyanate group, an acryloyl group, and a methacryloyl group. If necessary, these groups may be introduced at the terminal before introducing the hydrolyzable silyl group.
For example, when the functional group at the end of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with a hydrolyzable silyl group is a hydroxyl group, by reacting the hydroxyl group with acrylic acid or methacrylic acid In addition, an acryloyl group or a methacryloyl group can be introduced at the molecular end.
Alternatively, when the functional group at the terminal of the prepolymer (P) or the chain-extended polyurethane is an isocyanate group, an acryloyl group or a methacryloyl group can be introduced at the molecular terminal by reacting with hydroxyalkyl acrylates or hydroxyalkyl methacrylates.
Examples of hydroxyalkyl acrylates include hydroxyethyl acrylate and hydroxybutyl acrylate. Examples of hydroxyalkyl methacrylates include hydroxyethyl methacrylate and hydroxybutyl methacrylate.

Examples of aminosilanes include 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-aminopropyltriisopropoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3- ( 2-aminoethyl) aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropylmethyldimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropylmethyl Diethoxysilane, 3- (2-aminoethyl) aminopropyltriisopropoxysilane, 3- (2- (2-aminoethyl) aminoethyl) aminopropyltrimethoxysilane, 3- (6-aminohexyl) aminopropyltri Methoxysila 3- (N-ethylamino) -2-methylpropyltrimethoxysilane, N- (2-aminoethyl) aminomethyltrimethoxysilane, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxymethylsilane Ureidopropyltrimethoxysilane, ureidopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenylaminomethyltrimethoxysilane, N-benzyl-3-aminopropyltrimethoxysilane, N-vinylbenzyl -3-aminopropyltriethoxysilane, N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole, N-cyclohexylaminomethyltriethoxysilane, N-cyclohexylaminomethyldiethoxy Chirushiran, N- phenylaminomethyltrimethoxysilane, (2-aminoethyl) aminomethyl trimethoxy silane, N, N'-bis [3- (trimethoxysilyl) propyl] ethylenediamine, and the like.
Among these, 3-aminopropyltrimethoxysilane or 3-aminopropyltriethoxysilane is preferable.

  The reaction between an amino group and an isocyanate group is a urea bond formation reaction. In this reaction, the above-mentioned urethanization catalyst may be used. The reaction between an amino group and an acryloyl group is a Michael addition reaction.

<Method using mercaptosilanes (Q3)>
When the terminal functional group of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with a hydrolyzable silyl group is a group capable of reacting with a mercapto group, the terminal functional group A hydrolyzable silyl group can be introduced by reacting mer with mercaptosilanes.

Examples of the group capable of reacting with a mercapto group are an isocyanate group, an acryloyl group, and an allyl group. If necessary, these groups may be introduced at the terminal before introducing the hydrolyzable silyl group.
The isocyanate group and acryloyl group are the same as in the method (Q2) using aminosilanes.
For example, when the functional group at the end of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with a hydrolyzable silyl group is an isocyanate group, an allyl group is formed at the molecular end by reacting with allyl alcohol. Can be introduced.

  Mercaptosilanes include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, mercaptomethyltrimethoxysilane, mercaptomethyltriethoxysilane. Etc. Among these, 3-mercaptopropyltrimethoxysilane or 3-mercaptopropyltriethoxysilane is preferable.

  The reaction between the mercapto group and the isocyanate group is the same as the urethanization reaction, and a urethanization reaction catalyst may be used. The reaction between the mercapto group and the acryloyl group or allyl group is preferably performed using a radical initiator. Examples of the radical initiator include azobisisobutyronitrile (AIBN).

<Method (Q4) using epoxy silanes>
When the functional group at the end of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with the hydrolyzable silyl group is a group capable of reacting with an epoxy group, A hydrolyzable silyl group can be introduced by reacting a functional group with epoxy silanes.
Examples of the group capable of reacting with an epoxy group are a hydroxyl group and an amino group.

  As epoxy silanes, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane 2- (3,4-epoxycyclohexyl) ethyltriethoxysilane and the like are preferable. Among these, 3-glycidoxypropyltrimethoxysilane or 3-glycidoxypropyltriethoxysilane is preferable.

  As the catalyst in the reaction with the epoxy group, known ones such as amines and acid anhydrides are used. Examples include chain aliphatic polyamines, alicyclic polyamines, aromatic polyamines, modified aliphatic polyamines, imidazole compounds, and the like. In particular, tertiary amines such as N, N-dimethylpiperazine, triethylenediamine, 2,4,6-tris (dimethylaminomethyl) phenol (DMP-30) and benzyldimethylamine (BDMA) are preferable.

<Method (Q5) using hydrosilanes>
When the terminal functional group of the polyol (Z), prepolymer (P) or chain-extended polyurethane to be introduced with a hydrolyzable silyl group is a group capable of hydrosilylation reaction, the terminal functional group and the hydrosilane A hydrolyzable silyl group can be introduced by reacting with a group.
The group capable of hydrosilylation reaction is, for example, an acryloyl group or an allyl group, and these groups are introduced into the terminal of the polyol (Z), prepolymer (P) or chain-extended polyurethane. The method for introducing an acryloyl group or an allyl group is the same as the method (Q3) using mercaptosilanes.

Examples of hydrosilanes include trimethoxysilane, triethoxysilane, methyldiethoxysilane, methyldimethoxysilane, phenyldimethoxysilane, 1- [2- (trimethoxysilyl) ethyl] -1,1,3,3-tetramethyldi Examples thereof include siloxane.
It is preferable to use a hydrosilylation catalyst for this reaction. Examples of the hydrosilylation catalyst include chloroplatinic acid.

<Curable composition>
The curable composition concerning this invention contains a silyl group containing polymer (S). The curable composition may contain another polymer having a hydrolyzable silyl group other than the silyl group-containing polymer (S). 30 mass% or less of the whole curable composition is preferable, and, as for the content rate of the other polymer which has a hydrolyzable silyl group, 10 mass% or less is more preferable.

<Additives>
The curable composition according to the present invention may contain an additive. In the curable composition, it is preferable not to use a plasticizer. In particular, it is preferable not to use an ester plasticizer such as dioctyl phthalate. When ester plasticizers are used, the adhesive strength between the adhesive (cured body) and the substrate decreases, and adhesive deposits occur on the adherend when the adhesive is peeled off from the adherend. Because there is.
[Curing agent]
The curable composition according to the present invention is cured by contact with water. Therefore, it reacts with water in the atmosphere and is cured by moisture. Also, just prior to curing, water (H 2 _O) may be added as a curing agent. In this case, the amount of water added is 0.01 to 5 parts by mass with respect to 100 parts by mass of the total amount of the silyl group-containing polymer (S) and the other polymer having hydrolyzable silyl groups. Preferably, 0.01-1 mass part is more preferable, and 0.05-0.5 mass part is especially preferable. Curing can be effectively accelerated by setting the addition amount of the curing agent to 0.01 parts by mass or more, and the pot life at the time of use can be secured by setting the addition amount of the curing agent to 5 parts by mass or less.

[Curing catalyst]
The curable composition preferably contains a curing catalyst (curing accelerator) for accelerating the hydrolysis and / or crosslinking reaction of the hydrolyzable silyl group.
As such a curing catalyst, a known catalyst can be appropriately used as a component for promoting the reaction of the hydrolyzable silyl group. Specific examples include dibutyltin diacetate, dibutyltin dilaurate, dioctyltin _{dilaurate, (n-C 4 H 9} ) 2 Sn (OCOCH = CHCOOCH 3) 2, (n-C 4 H 9) 2 Sn (OCOCH = CHCOO (n _{-C 4 H 9)) 2,} (n-C 8 H 17) 2 Sn (OCOCH = CHCOOCH 3) 2, (n-C 8 H 17) 2 Sn (OCOCH = CHCOO (n-C 4 H 9)) ₂ , (n-C ₈ H ₁₇ ) ₂ Sn (OCOCH═CHCOO (iso-C ₈ H ₁₇ )) ₂ Organotin carboxylates such as ₂ ; (nC ₄ H ₉ ) ₂ Sn (SCH ₂ COO), ( _{n-C 8 H 17) 2} Sn (SCH 2 COO), (n-C 8 H 17) 2 Sn (SCH 2 CH 2 COO), (n-C 8 H 17) 2 _{n (SCH 2 COOCH 2 CH 2} OCOCH 2 S), (n-C 4 H 9) 2 Sn (SCH 2 COO (iso-C 8 H 17)) 2, (n-C 8 H 17) 2Sn (SCH 2 _{COO (iso-C 8 H 17} )) 2, (n-C 8 H 17) 2 Sn (SCH 2 COO (n-C 8 H 17)) 2, (n-C 4 H 9) such as 2 SnS including Sulfur organotin compounds; organotin oxides such as (nC ₄ H ₉ ) ₂ SnO, (nC ₈ H ₁₇ ) ₂ SnO; ethyl silicate, dimethyl maleate, diethyl maleate, dioctyl maleate, dimethyl phthalate, an ester compound selected from the group consisting of diethyl phthalate and dioctyl phthalate, reaction products of the organic tin _{oxide; (n-C 4 H 9} ) 2 Sn (acac) _{, (N-C 8 H 17} ) 2 Sn (acac) 2, (n-C 4 H 9) 2 Sn (OC 8 H 17) (acac), (n-C 4 H 9) 2 Sn (OC (CH _{3) CHCO 2 C 2 H 5} ) 2, (n-C 8 H 17) 2 Sn (OC (CH 3) CHCO 2 C 2 H 5) 2, (n-C 4 H 9) 2 Sn (OC 8 H ₁₇ ) (OC (CH ₃ ) CHCO ₂ C ₂ H ₅ ), chelating tin compounds such as bisacetylacetonatotin (wherein acac means an acetylacetonato ligand, OC (CH ₃ ) CHCO ₂ C ₂ H ₅ means an ethyl acetoacetate ligand. ); Reaction product of alkoxysilane selected from the group consisting of tetramethoxysilane, tetraethoxysilane, and tetrapropoxysilane and the above-mentioned chelated tin compound; (nC ₄ H ₉ ) ₂ (CH ₃ COO) SnOSn (OCO)
_{CH 3) (n-C 4} H 9) 2, (n-C 4 H 9) 2 (CH 3 O) SnOSn (OCH 3) (n-C 4 H 9) 2 , etc. -SnOSn--containing organic tin And tin compounds such as compounds.

  As further specific examples of the curing catalyst, divalent tin carboxylates such as tin 2-ethylhexanoate, tin n-octylate, tin naphthenate or tin stearate; octyl acid, oleic acid, naphthenic acid or stearin Metal salts other than tin of organic carboxylic acids such as acids; bismuth carboxylates such as calcium carboxylate, zirconium carboxylate, iron carboxylate, vanadium carboxylate, bismuth tris-2-ethylhexanoate, lead carboxylate, carboxylic acid Titanium or nickel carboxylate; titanium alkoxides such as tetraisopropyl titanate, tetrabutyl titanate, tetramethyl titanate, tetra (2-ethylhexyl titanate); aluminum isopropylate, mono-sec-butoxyaluminum diisopropylate Aluminum alkoxides; zirconium alkoxides such as zirconium-n-propylate and zirconium-n-butyrate; titanium chelates such as titanium tetraacetylacetonate, titanium ethylacetoacetate, titanium octylene glycolate and titanium lactate; aluminum trisacetyl Aluminum chelates such as acetonate, aluminum trisethyl acetoacetate, diisopropoxyaluminum ethyl acetoacetate; zirconium compounds such as zirconium tetraacetylacetonate, zirconium bisacetylacetonate, zirconium acetylacetonate bisethylacetoacetate, zirconium acetate Acidic compounds such as phosphoric acid, p-toluenesulfonic acid or phthalic acid; Aliphatic monoamines such as amine, hexylamine, octylamine, decylamine and laurylamine; Aliphatic diamines such as ethylenediamine and hexanediamine; Aliphatic polyamines such as diethylenetriamine, triethylenetetramine and tetraethylenepentamine; Piperidine and piperazine Heterocyclic amines such as 1,8-diazabicyclo (5.4.0) undecene-7; aromatic amines such as metaphenylenediamine; alkanolamines such as monoethanolamine, diethanolamine or triethanolamine; triethylamine Trialkylamines such as: the above amines and aliphatic monocarboxylic acids (formic acid, acetic acid, octylic acid, 2-ethylhexanoic acid, etc.), aliphatic polycarboxylic acids (succinic acid, malonic acid, succinic acid, glutaric acid, adipine) Acid), aromatic monocarboxylic acids (benzoic acid, toluic acid, ethylbenzoic acid, etc.), aromatic polycarboxylic acids (phthalic acid, isophthalic acid, terephthalic acid, nitrophthalic acid, trimellitic acid, etc.), phenolic compounds (phenol) , Resorcinol, etc.), sulfonic acid compounds (alkylbenzenesulfonic acid, toluenesulfonic acid, benzenesulfonic acid, etc.), organic acids such as phosphoric acid compounds, and acids such as inorganic acids such as hydrochloric acid, bromic acid, sulfuric acid, etc. ~ Tertiary ammonium-acid salts; triethylmethylammonium hydroxide, trimethylbenzylammonium hydroxide, hexyltrimethylammonium hydroxide, octyltrimethylammonium hydroxide, decyltrimethylammonium hydroxide, dodecyltrimethylammonium Droxide, octyldimethylethylammonium hydroxide, decyldimethylethylammonium hydroxide, dodecyldimethylethylammonium hydroxide, dihexyldimethylammonium hydroxide, dioctyldimethylammonium hydroxide, didecyldimethylammonium hydroxide, didodecyldimethylammonium hydroxide, etc. And ammonium compounds such as various modified amines used as curing agents for epoxy resins.

These curing catalysts may be used alone or in combination of two or more. When two or more types are combined, for example, the above-mentioned metal-containing compound such as a reaction product of the divalent tin carboxylate, organotin carboxylate or organotin oxide and an ester compound, an aliphatic monoamine or other amine compound It is preferable to combine these because excellent curability can be obtained.
When the curing catalyst is added, the addition amount is preferably 0.001 to 10 parts by mass with respect to 100 parts by mass of the total amount of the silyl group-containing polymer (S) and other polymers. 01-5 mass parts is more preferable. By making the addition amount of the curing catalyst 0.001 part by mass or more, the curing rate can be effectively accelerated, and by making the addition amount of the curing catalyst 10 parts by mass or less, the pot life during use can be secured.

[solvent]
The curable composition concerning this invention may contain a solvent as needed.
The solvent is not particularly limited. For example, aliphatic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, alcohols, ketones, esters, ethers, ester alcohols, ketone alcohols, ether alcohols , Ketone ethers, ketone esters or ester ethers.
Among these, it is preferable to use alcohols as the solvent because the storage stability of the curable composition can be improved. The alcohol is preferably an alkyl alcohol having 1 to 10 carbon atoms, more preferably methanol, ethanol, isopropyl alcohol, isopentyl alcohol or hexyl alcohol, and further preferably methanol or ethanol. In particular, when methanol is used, the curing time of the curable composition can be increased by increasing the amount of addition. This is an effective technique for prolonging the so-called pot life of the curable composition until it reaches a predetermined viscosity after preparation.
When adding a solvent to a curable composition, it is preferable that the addition amount is 500 mass parts or less with respect to 100 mass parts of total amounts of a silyl group containing polymer (S) and another polymer, 1 More preferably, it is -100 mass parts. When the addition amount exceeds 500 parts by mass, the cured product (adhesive) may shrink as the solvent volatilizes.

[Dehydrating agent]
In order to improve the storage stability, the curable composition according to the present invention may contain a small amount of a dehydrating agent as long as the effects of the present invention are not impaired.
Specific examples of such dehydrating agents include alkyl orthoformate such as methyl orthoformate and ethyl orthoformate; alkyl orthoacetate such as methyl orthoacetate and ethyl orthoacetate; methyltrimethoxysilane, vinyltrimethoxysilane, tetramethoxysilane or tetra Examples include hydrolyzable organic silicone compounds such as ethoxysilane; hydrolyzable organic titanium compounds and the like. Among these, vinyltrimethoxysilane or tetraethoxysilane is preferable from the viewpoints of cost and dehydration ability.
When adding a dehydrating agent to a curable composition, the addition amount shall be 0.001-30 mass parts with respect to 100 mass parts of the total amount of a silyl group containing polymer (S) and another polymer. Is preferable, and it is more preferable that it is 0.01-10 mass parts.

[Other additives]
You may mix | blend the following filler, reinforcing agent, stabilizer, flame retardant, antistatic agent, mold release agent, antifungal agent, etc. with a curable composition.
Examples of the filler or reinforcing agent include carbon black, aluminum hydroxide, calcium carbonate, titanium oxide, silica, glass, bone powder, wood powder, or fiber flake.
Examples of the stabilizer include an antioxidant, an ultraviolet absorber, and a light stabilizer.
Examples of the flame retardant include chloroalkyl phosphate, dimethylmethylphosphonate, ammonium polyphosphate, or an organic bromine compound.
Examples of the mold release agent include wax, soaps, or silicone oil. Examples of the antifungal agent include pentachlorophenol, pentachlorophenol laurate, bis (tri-n-butyltin) oxide, and the like.
Moreover, you may add an adhesiveness imparting agent to the curable composition for the purpose of improving adhesiveness with a base material.

<Method for producing adhesive sheet>
The pressure-sensitive adhesive body of the present invention is suitably used as a pressure-sensitive adhesive layer for pressure-sensitive adhesive sheets. The pressure-sensitive adhesive sheet is provided with a pressure-sensitive adhesive layer on a base material, and the surface of the pressure-sensitive adhesive layer opposite to the base material is used as a pressure-sensitive adhesive surface having removability. Moreover, the peeling sheet is laminated | stacked on the surface on the opposite side to the base material of this adhesive body layer, and the structure which peels a peeling sheet at the time of use and exposes an adhesive surface may be sufficient. Or the base material consists of a peeling sheet, and the double-sided adhesive sheet by which the peeling sheet was laminated | stacked on one or both of the front and back both surfaces of an adhesive body layer may be sufficient. If the release sheet is peeled off when the double-sided pressure-sensitive adhesive sheet is used, both front and back surfaces become pressure-sensitive adhesive surfaces having removability. In addition, in this specification, the thickness of an adhesive sheet is not ask | required, and a sheet | seat and a film are not distinguished.

The method for producing a pressure-sensitive adhesive sheet of the present invention comprises a step of forming an uncured layer comprising a curable composition containing a silyl group-containing polymer (S) on a substrate, and the opposite side of the substrate of the uncured layer. A step of curing the uncured layer in a state where the surface is exposed or in a state where a release sheet is laminated on the surface.
The curable composition containing the silyl group-containing polymer (S) has excellent curability, and when it comes into contact with moisture, it cures rapidly and firmly (moisture curing) to obtain a cured product. A hydrolyzable silyl group (—SiX _a R ³ _(3-a) ) contributes to the moisture curing.
It can also be formed by cutting, die cutting or the like after curing of the curable composition.

  The curing conditions for the curable composition are set as necessary. For example, a curable composition to which a curing catalyst is added is prepared. A predetermined amount of water is added to this as a curing agent and mixed well. This is coated on a base material to form an uncured layer. Then, it can be cured by heating in an oven or the like and curing at room temperature with the surface of the uncured layer exposed or with a release sheet laminated on the surface. It is also effective to leave it in a humidified environment when curing at room temperature or after curing. The heating by the oven or the like is appropriately set depending on the heat resistance temperature of the base material and the release sheet. For example, it is preferable to leave in an environment of 60 to 120 ° C. for about 1 to 30 minutes. In particular, when a solvent is used, it is preferable to set a certain drying time. However, rapid drying is not preferable because it causes foaming. Steam may also be applied in or after removal from the oven.

  When the uncured layer is cured, good adhesion between the cured body (adhesive body) and the substrate is obtained, and the exposed surface of the uncured layer or the surface in close contact with the release sheet is removable. It becomes the adhesive surface which has.

<Base material>
The material of the substrate is not particularly limited. Preferred examples include polyesters such as polyethylene terephthalate (PET); polyolefins such as polyethylene, polypropylene, and polyethylene-polypropylene copolymers (block copolymers and random copolymers); halogenated polyolefins such as polyvinyl chloride; Examples include paper such as cardboard; cloth such as woven fabric and nonwoven fabric; metal foil such as aluminum foil. These base materials may be used in combination. For example, you may use the laminated body which laminated | stacked the PET layer, the metal foil layer, and the polyethylene layer.
The surface of the substrate may not be processed in advance. In particular, the joint surface with the pressure-sensitive adhesive layer of polyesters and papers is difficult to peel off due to the adhesive effect accompanying the curing of the curable composition without prior processing. You may coat a primer etc. as needed.
On the other hand, when using polyolefin for a base material, it is preferable to process beforehand the surface which coats a curable composition. This is because the peel adhesive strength may be lowered on an untreated surface. That is, examples of the prior treatment for the surface of the substrate on which the curable composition of the substrate using polyolefins is applied include corona treatment (corona discharge treatment) and primer treatment. In particular, the corona treatment is preferable because the treatment is simple and the process can be simplified.

<Peeling sheet>
As the release sheet, papers that have been surface-treated with a general release agent; the above-mentioned untreated polyolefins: such as those obtained by laminating polyolefins on a base material such as papers, etc., have weak adhesion to the pressure-sensitive adhesive layer. Anything is acceptable.
When a release sheet is used as the substrate, a pressure-sensitive adhesive body having removability on both front and back surfaces is obtained.

<Adhesive>
The pressure-sensitive adhesive body of the present invention has a low peel strength after curing and good re-peelability as shown in the examples described later.
Specifically, the peel adhesive strength exceeds 0 N / 25 mm and is 8 N / 25 mm or less, preferably exceeds 0 N / 25 mm and is 1 N / 25 mm or less, more preferably 0.005 to 0.8 N / 25 mm. A pressure sensitive adhesive body is obtained. It is preferable that the curable composition concerning this invention does not contain the additive which increases adhesiveness.

Further, in the temperature characteristic of loss tangent (tan δ) expressed by the ratio of loss elastic modulus to storage elastic modulus (loss elastic modulus / storage elastic modulus), tan δ is 0.1 or more in the temperature range of 0 to 40 ° C. , Have preferable physical properties as a damping material.
Damping material converts vibration energy into thermal energy and absorbs vibration. The vibration absorbing capacity of the damping material is generally the ratio of loss elastic modulus to storage elastic modulus (loss elastic modulus / storage elastic modulus). The loss tangent (tan δ) expressed is an index. As tan δ is larger, vibration energy is more easily converted into heat energy and consumed, and vibration damping by vibration absorption is more likely to be exhibited.
When tan δ is large in a wide temperature range as described above, good vibration damping properties are easily obtained stably even when the vibration damping material is used in various indoor or outdoor temperature conditions.
The value of loss tangent (tan δ) in this specification is obtained by cutting each cured film (thickness: 100 μm) into a rectangular shape having a length of 20 mm and a width of 10 mm to prepare an evaluation sample, and measuring dynamic viscoelasticity Tan δ was measured in a tensile mode with an apparatus (manufactured by SII, product name: EXSTAR DMS6100). Tan δ was measured at a frequency of 10 Hz in the range of −100 to 150 ° C., and the temperature dependency was evaluated.

Although the reason why the cured product obtained by curing the curable composition containing the silyl group-containing polymer (S) exhibits slight adhesion or low adhesion is not clear, a hydrolyzable silyl group (-SiX _a R ³ _{(3 -A)} ), the structural unit derived from the dicarboxylic anhydride (b), the urethane bond, and the urea bond are considered to contribute.
The urethane bond is formed by the reaction of an isocyanate group and a hydroxyl group, and the urea bond is formed by the reaction of an isocyanate group and an amino group.

That is, the polyol (Z) has a structural unit derived from the dicarboxylic acid anhydride (b), and the prepolymer (P) and the chain extended polyurethane further have a urethane bond. Further, when a hydrolyzable silyl group is introduced into the polyol (Z), the prepolymer (P) or the chain extended polyurethane, a urethane bond or a urea bond can be introduced into the silyl group-containing polymer (S).
Since the ester bond, urethane bond, and urea bond of the structural unit derived from the dicarboxylic acid anhydride (b) are polar bonds, these are cohesive forces in the silyl group-containing polymer (S), It is considered to act in the direction of increasing the adhesiveness and the adhesion to the adherend. On the other hand, the hydrolyzable silyl group is considered to act in the direction of lowering the adhesiveness of the adhesive to the adherend. And it is thought that slight adhesiveness or low adhesiveness is expressed by these interactions. Further, since the position at which the hydrolyzable silyl group is introduced is the molecular end, the cohesive force can be increased without hindering the molecular motion, and the adhesive force can be stably exhibited.
Therefore, in the silyl group-containing polymer (S), the ratio (MEU / MS molar ratio) of the total amount (MEU) of ester bond, urethane bond and urea bond and the amount of hydrolyzable silyl group (MS) is controlled. By doing so, it is possible to control the adhesive force of the adhesive body. In order to obtain an adhesive having a peel adhesive strength of 8 N / 25 mm or less, the MEU / MS molar ratio is preferably in the range of 2/1 to 100/1, and is preferably 2/1 to 90/1. It is more preferable. The MEU / MS molar ratio can be controlled, for example, by adjusting the molecular weight of the polyol (Z), prepolymer (P), or chain extended polyurethane.

  The reason why the cured product (adhesive) obtained by curing the curable composition containing the silyl group-containing polymer (S) exhibits high tan δ is not clear, but has a bent chain derived from dicarboxylic anhydride. It is considered that vibration absorption due to heat generation is expressed due to the influence of the substituent derived from the dicarboxylic acid compound.

  The thickness of the pressure-sensitive adhesive body of the present invention is not particularly limited, but is preferably 10 μm or more, more preferably 20 μm or more, and more preferably 30 μm or more for obtaining good vibration damping properties. Further, from the viewpoint of stability of adhesive strength and economical efficiency, it is preferably 200 μm or less, more preferably 100 μm or less, and further preferably 80 μm or less.

<Applications of adhesives>
The pressure-sensitive adhesive body of the present invention has good heat resistance and removability, has good vibration damping properties, and provides impact resistance. Thus, for example, protective sheets for electronic materials such as electronic substrates and IC chips; protective sheets for optical members such as polarizing plates, light diffusing plates, light diffusing sheets, prism sheets; protective sheets for various displays; protective sheets for automobiles; Surface protective film for plate material; decorative sheet for wall covering; suitably used as pressure-sensitive adhesive layer for surface protective material of products such as metal plate, coated steel plate, synthetic resin plate, decorative plywood, heat reflection glass.
According to the present invention, since the vibration damping property can be imparted to these protective sheet, protective tape, and surface protective material, impact resistance can be obtained.

  Hereinafter, the present invention will be described in more detail using examples, but the present invention is not limited to these examples.

(Reference Production Example 1: Production of double metal cyanide complex catalyst)
Zinc hexacyanocobaltate (hereinafter referred to as TBA-DMC catalyst) having tert-butyl alcohol as an organic ligand was produced by the following method. The polyol X in this example is a polyol having a number average molecular weight (Mn) of 1000 obtained by addition polymerization of propylene oxide to dipropylene glycol.
First, an aqueous solution consisting of 10.2 g of zinc chloride and 10 g of water was placed in a 500 ml flask, and while maintaining the aqueous solution at 40 ° C., stirring at 300 rpm (300 rpm), 4.2 g An aqueous solution composed of potassium hexacyanocobaltate (K ₃ [Co (CN)] ₆ ) and 75 g of water was added dropwise over 30 minutes. After completion of the dropwise addition, the mixture was further stirred for 30 minutes. Thereafter, a mixture of 40 g of ethylene glycol mono-tert-butyl ether (hereinafter abbreviated as EGMTBE), 40 g of tert-butyl alcohol (hereinafter abbreviated as TBA), 80 g of water, and 0.6 g of polyol X was obtained. The mixture was added to the mixture and stirred at 40 ° C. for 30 minutes and further at 60 ° C. for 60 minutes. The obtained reaction mixture was filtered for 50 minutes under pressure (0.25 MPa) using a circular filter plate having a diameter of 125 mm and a quantitative filter paper for fine particles (No. 5C manufactured by ADVANTEC Co.) to obtain a solid. separated.
Next, a mixture comprising 18 g of EGMTBE, 18 g of TBA, and 84 g of water was added to the cake containing the double metal cyanide complex and stirred for 30 minutes, followed by pressure filtration (filtration time: 15 minutes). It was. To the cake containing the double metal cyanide complex obtained by filtration, a mixture of 54 g EGMTBE, 54 g TBA, and 12 g water was added and stirred for 30 minutes, and the double metal cyanide having an organic ligand was stirred. A slurry of EGMTBE / TBA containing the complex was obtained. This slurry was used as a TBA-DMC catalyst.
About 5 g of this slurry was weighed into a flask, dried roughly with a nitrogen stream, and then dried under reduced pressure at 80 ° C. for 4 hours. As a result of weighing the obtained solid, it was found that the concentration of the double metal cyanide complex contained in the slurry was 4.70% by mass.

Example 1
Under the production conditions shown in Table 1, a silyl group-containing polymer (S3-1) of the third embodiment was prepared.
[Production of isocyanate group-terminated prepolymer (PI-1)]
The initiator (a1) is a polyoxypropylene having a hydroxyl value of 160.3 mgKOH / g and a molecular weight of 700 produced by reacting propylene glycol with propylene oxide (hereinafter sometimes referred to as PO) using a KOH catalyst. Diol was used.
First, a mixture of propylene oxide and phthalic anhydride in a molar ratio (PO / phthalic anhydride) of 75/25 is used as an initiator (a1) in the presence of the TBA-DMC catalyst obtained in Reference Production Example 1 in the ring-opening polymerization. A hydroxyl value of 57.9 mg KOH / g (hydroxyl value converted molecular weight 1937), an average molecular weight per copolymer chain (M ′) 618.5, an acid value of 0.14 mg KOH / g, and a constituent unit derived from the initiator (a1). A polyester ether polyol (Z1) having a content of 36% by mass and a content of structural units derived from phthalic anhydride of 30% by mass was obtained.

Next, 645.9 g of the polyester ether polyol (Z1) obtained above in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, and 2,4 as the polyisocyanate (B). Along with 87.1 g of tolylene diisocyanate (hereinafter referred to as TDI-100, manufactured by Nippon Polyurethane Industry Co., Ltd., trade name: Coronate T-100), dibutyltin dilaurate (DBTDL) as a urethanization catalyst, polyester ether polyol (Z1) And an amount corresponding to 25 ppm with respect to the total amount of TDI-100. The isocyanate index in the charged amount was 150.
Next, the temperature was gradually raised to 85 ° C., and a prepolymer generation reaction was performed for 3 hours to obtain an isocyanate group-terminated prepolymer (PI-1). In the obtained isocyanate group-terminated prepolymer (PI-1), the isocyanate group content (hereinafter referred to as NCO%) was 1.76% by mass.
[Chain extension reaction]
Then, after cooling to room temperature, 157.1 g of ethyl acetate and 157.1 g of methyl ethyl ketone (MEK) were added, and 1,4-butanediol as a chain extender was added to the isocyanate group-terminated prepolymer (PI-1). It added so that an isocyanate index might be set to 130 with respect to an isocyanate group (NCO group), and it was made to react at 60 degreeC, and the chain extension polyurethane of the isocyanate group terminal was obtained. NCO% of the obtained chain extension polyurethane was 0.28 mass%.

[Introduction of hydrolyzable silyl group]
1.05 equivalent of aminopropyltrimethoxysilane was added to the NCO group of the obtained chain-extended polyurethane resin and reacted to obtain a silyl group-containing polymer (S3-1) having a trimethoxysilyl group. The hydrolyzable silyl group introduction ratio was 100 mol%.
Mw of the silyl group-containing polymer (S3-1) was 81000, Mn was 26000, Mw / Mn was 3.1, and the molar ratio of MEU / MS was 79.
Moreover, a solvent can be added as needed. In this example, 209.4 g of ethyl acetate and 209.4 g of methyl ethyl ketone (MEK) are further added as a solvent to prepare a solution having a solid content concentration of 50% by mass containing the silyl group-containing polymer (S3-1). Was measured with an E-type viscometer to obtain a pressure-sensitive adhesive composition having a viscosity of 6500 mPa · s.

<Evaluation>
To 100 parts by mass of the silyl group-containing polymer (S3-1) obtained in Example 1, 0.03 part by mass of water (H ₂ O) as a curing agent and 1 part by mass of dibutyltin dilaurate as a curing catalyst It added and mixed and the curable composition was obtained.
The obtained curable composition was applied onto a PET film (base material) having a thickness of 100 μm so that the film thickness after drying was 5 μm, 15 μm, 25 μm, and 50 μm, respectively, and 100 ° C. in a circulation oven. For 3 minutes. Then, the pressure-sensitive adhesive layer was formed by curing for one week at 23 ° C. and 50% relative humidity. Thus, four types of pressure-sensitive adhesive sheets having different thicknesses of the pressure-sensitive adhesive layer were obtained.

[Peel strength]
The obtained pressure-sensitive adhesive sheet (width 25 mm) was stuck on a bright steel annealed stainless steel plate having a thickness of 1.5 mm at room temperature (23 ° C.) and pressure-bonded with a 2 kg rubber roll. After 30 minutes at room temperature, 24 hours at room temperature, 1 week at 60 ° C., 2 weeks at 60 ° C., 3 weeks at 60 ° C., and 4 weeks at 60 ° C., tensile testers (Orientec) specified in JIS B 7721, respectively. Peel strength (180 degree peel, tensile speed 300 mm / min) was measured using RTE-1210 manufactured by the company. The results are shown in Table 2. Table 1 also shows the measurement results of peel strength when the thickness of the pressure-sensitive adhesive layer is 15 μm.
The smaller this value, the lower the adhesive strength, the easier it is to peel off, and the better the removability. The value of the peel strength after 30 minutes at room temperature corresponds to the “peel strength” in the present invention.
Table 2 also shows the ratio of the peel strength after 3 weeks at 60 ° C. (after 3 weeks / 30 minutes), based on the peel strength after 30 minutes. A larger value indicates a greater increase in adhesive strength with time.

[Vibration control]
The same curable composition used for the measurement of the said peeling strength was used. The curable composition was applied to an OPP (biaxially oriented polypropylene) film (thickness: 100 μm) and cured for one week under conditions of 23 ° C. and humidity of 50%. This was cut into a rectangular shape having a length of 20 mm and a width of 10 mm, and peeled off from the OPP film to prepare an evaluation sample having a thickness of 100 μm. Tan δ was measured in a tensile mode using a dynamic viscoelasticity measuring apparatus (manufactured by SII, product name: EXSTAR DMS6100). Tan δ was measured at a frequency of 10 Hz in the range of −100 to 150 ° C., and the temperature dependency was evaluated. The result is shown in FIG. In the graph of FIG. 1, the left vertical axis represents storage elastic modulus (E ′, unit: Pa) and loss elastic modulus (E ″, unit: Pa), the right vertical axis represents loss tangent (tan δ), and the horizontal axis. Represents the measured temperature (unit: ° C).
As shown in the graph of FIG. 1, the pressure-sensitive adhesive obtained by curing the silyl group-containing polymer (S3-1) of Example 1 has a large tan δ value around room temperature, and is good around room temperature. It can be seen that it has excellent damping properties. The peak temperature and peak value of tan δ are shown in Table 1.

(Example 2)
In Example 1, the production conditions were changed as shown in Table 1 to synthesize a silyl group-containing polymer, and a curable composition and a pressure-sensitive adhesive were produced using the same (hereinafter the same). In this example, the silyl group-containing polymer (S2-1) of the second embodiment is used.

[Production of isocyanate group-terminated prepolymer (PI-2)]
In this example, the other polyol used in combination with the polyester ether polyol (Z1) was produced by reacting propylene oxide with propylene glycol as an initiator and using a KOH catalyst, having a hydroxyl value of 56.2 mgKOH / g, a molecular weight of 2, 000 polyoxypropylene diol is used.
That is, 530.0 g of the same polyester ether polyol (Z1) as in Example 1 in a four-necked flask equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, a thermometer, and a dropping funnel, and the above polyoxypropylene diol as another polyol Of DBTDL as a urethanization catalyst to 25 ppm based on the total amount of polyester ether polyol (Z1), other polyols and TDI-100, together with 537.5 g of TDI-100 as polyisocyanate (B) Prepared in a corresponding amount. In the charged amount, the isocyanate index was 133.
Subsequently, the temperature was gradually raised to 85 ° C., and a prepolymer generation reaction was performed for 3 hours to obtain an isocyanate group-terminated prepolymer (PI-2). In the obtained isocyanate group-terminated prepolymer (PI-2), the NCO% was 1.14% by mass.

[Introduction of hydrolyzable silyl group]
A silyl group-containing polymer (S2) having a trimethoxysilyl group is reacted by adding 1.05 equivalents of aminopropyltrimethoxysilane to the NCO group of the resulting isocyanate group-terminated prepolymer (PI-2). -1) was obtained. The hydrolyzable silyl group introduction ratio was 100 mol%.
Table 1 shows the Mw, Mn, Mw / Mn, MEU / MS molar ratio, and solution viscosity of the silyl group-containing polymer (S2-1).

(Example 3)
[Production of isocyanate group-terminated prepolymer (P2-2)]
In this example, the other polyol used in combination with the polyester ether polyol (Z1) was produced by reacting propylene oxide using propylene glycol as an initiator and a KOH catalyst, and having a hydroxyl value of 16.3 mgKOH / g and a molecular weight of 7000. Polyoxypropylene diol is used.
That is, 121.3 g of the same polyester ether polyol (Z1) as in Example 1 in a four-necked flask equipped with a stirrer, reflux condenser, nitrogen inlet tube, thermometer, and dropping funnel, and the above polyoxypropylene diol as another polyol Of DBDIL as a urethanization catalyst to 25 ppm based on the total amount of polyester ether polyol (Z1), other polyols and TDI-100, together with 836.1 g of TDI-100 as polyisocyanate (B) Prepared in a corresponding amount. In the charged amount, the isocyanate index was 133.
Subsequently, the temperature was gradually raised to 85 ° C., and a prepolymer generation reaction was performed for 3 hours to obtain an isocyanate group-terminated prepolymer (PI-2). In the obtained isocyanate group-terminated prepolymer (P2-2), the NCO% was 0.46% by mass.

[Introduction of hydrolyzable silyl group]
A silyl group-containing polymer (S2) having a trimethoxysilyl group is reacted by adding 1.05 equivalents of aminopropyltrimethoxysilane to the NCO group of the resulting isocyanate group-terminated prepolymer (PI-2). -2) was obtained. The hydrolyzable silyl group introduction ratio was 100 mol%.
Table 1 shows the Mw, Mn, Mw / Mn, MEU / MS molar ratio, and solution viscosity of the silyl group-containing polymer (S2-2).

(Example 4)
In this example, the silyl group-containing polymer (S1-1) of the first embodiment is used.
As the initiator (a2), polyoxypropylene diol having a hydroxyl value of 112 mgKOH / g and a molecular weight of 1000, produced by reacting propylene glycol with PO using a KOH catalyst, was used.
First, a mixture of propylene oxide and phthalic anhydride molar ratio (PO / phthalic anhydride) 79/21 was used as an initiator (a2) in the presence of the TBA-DMC catalyst obtained in Reference Production Example 1 in the ring-opening polymerization. Hydroxyl value 58.3 mgKOH / g, (hydroxyl value conversion molecular weight 1930), average molecular weight per copolymer chain (M ′) 464, acid value 0.11 mgKOH / g, content of structural unit derived from phthalic anhydride 20 A mass% polyester ether polyol (initiator: a3) was obtained. A mixture of a molar ratio of propylene oxide and phthalic anhydride (PO / phthalic anhydride) 91/9 was subjected to ring-opening polymerization in a3 in the presence of the TBA-DMC catalyst obtained in Reference Production Example 1, and a hydroxyl value of 17.3 mgKOH / G, (hydroxyl value converted molecular weight 6474), average molecular weight per copolymer chain (M ′) 2737, acid value 0.11 mg KOH / g, polyester ether polyol having a structural unit content of 20% by mass derived from phthalic anhydride ( Z2) was obtained.
[Introduction of hydrolyzable silyl group]
The reaction is carried out by adding 0.97 equivalents of isocyanate methyltrimethoxysilane to the hydroxyl group of the obtained polyester ether polyol (Z2) to obtain a silyl group-containing polymer (S1-1) having a trimethoxysilyl group. It was. The hydrolyzable silyl group introduction ratio was 97 mol%.
Table 1 shows the Mw, Mn, Mw / Mn, MEU / MS molar ratio and solution viscosity of the silyl group-containing polymer (S1-1).

<Evaluation>
About the silyl group containing polymer obtained in Examples 2-4, the curable composition was prepared like Example 1 and the adhesive sheet was produced. However, the thickness of the pressure-sensitive adhesive layer was 15 μm.
The peel strength of the obtained pressure-sensitive adhesive sheet was measured in the same manner as in Example 1. The results are shown in Table 1.
Further, the loss tangent (tan δ) was determined in the same manner as in Example 1. The peak temperature and peak value of tan δ are shown in Table 1.

As shown in the results of Tables 1 and 2, all of the pressure-sensitive adhesives obtained by curing the silyl group-containing polymers of Examples 1 to 4 have small peel strength after 30 minutes and good removability. Have. Moreover, the heat resistance is also good, and even at a high temperature of 60 ° C., it exhibits good fine-medium to medium-adhesiveness after 4 weeks, and has a high tan δ value at room temperature and good vibration damping properties.
From the results in Table 2, the ratio of peel strength after 3 weeks at 60 ° C. (after 3 weeks / after 30 minutes) based on the peel strength after 30 minutes is smaller as the thickness of the pressure-sensitive adhesive is thicker. I understand that.

(Comparative Example 1)
In this example, a silyl group-containing polymer having no ester bond, urethane bond, or urea bond was used.
120 g of polyoxypropylene diol (hereinafter referred to as diol A) of Mn = 3000 obtained by ring-opening polymerization of propylene oxide (PO) with dipropylene glycol, and Mn = obtained by ring-opening polymerization of PO with glycerin A mixture of 200 g of 5000 polyoxypropylene triol (hereinafter referred to as triol B) was used as an initiator, and 2480 g of PO was gradually added to the reaction vessel in the presence of 1.2 g of zinc hexacyanocobaltate-glyme complex catalyst. The polymerization reaction was carried out under the condition of 120 ° C., and after the total amount of PO was added, the reaction was continued until the internal pressure of the reaction vessel was not lowered. The zinc hexacyanocobaltate-glyme complex catalyst can be produced using glyme instead of EGMTBE and TBA in Reference Production Example 1.
Subsequently, 120 g of diol A and 200 g of triol B were charged into the reaction vessel, and after 1680 g of PO was added little by little in the same manner as described above, the reaction was continued until the internal pressure of the reaction vessel did not decrease. Further, 120 g of diol A and 200 g of triol B were put into the reaction vessel, and after 1280 g of PO was added little by little in the same manner as described above, the reaction was continued until the internal pressure of the reaction vessel was not lowered. Further, 80 g of diol A and 130 g of triol B were put into the reaction vessel, and 590 g of PO was added little by little in the same manner as described above, and the reaction was continued until the internal pressure of the reaction vessel could not be lowered.
Further, 60 g of diol A and 100 g of triol B were added, and after 240 g of PO was added little by little in the same manner as described above, the reaction was continued until the internal pressure of the reaction vessel was not lowered.
Finally, 75 g of diol A and 125 g of triol B were added, 200 g of PO was added little by little in the same manner as described above, and the reaction was continued until the internal pressure of the reaction vessel was not lowered.
By this operation, polyoxypropylene polyol F having Mn of 17,000 and Mw / Mn of 1.76 was obtained.

To the obtained polyoxypropylene polyol F, a methanol solution of 1.05 equivalent of sodium methoxide of the hydroxyl group was added, and methanol was distilled off under reduced pressure by heating to convert the terminal hydroxyl group of the polyoxypropylene polyol to sodium alkoxide. Converted. Next, this was reacted with allyl chloride, then unreacted allyl chloride was removed, and the salt formed as a by-product was purified and removed to obtain polyoxypropylene having a terminal allyl group. In contrast, methyldimethoxysilane was reacted in the presence of a platinum catalyst to obtain an oxypropylene polymer having a methyldimethoxysilyl group at the terminal.
Mn of the obtained polymer was 20,000, Mw / Mn was 1.35, and the viscosity (solid content concentration 100% by mass) was 19,500 mPa · s / 25 ° C.

[Evaluation]
The oxypropylene polymer obtained in Comparative Example 1 was applied on a PET film (base material) having a thickness of 100 μm so that the film thickness after drying was 50 μm, and the resultant was circulated in an oven at 100 ° C. for 5 minutes. Dried. And it cured at 23 degreeC and relative humidity 65% for one week, the adhesion layer was formed, and the adhesive sheet was obtained.
The peel strength after 30 minutes of the pressure-sensitive adhesive sheet was 0.23 N / 25 mm. “Generating” means that the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet is not in close contact with the base material and is in a state of being thrown and destroyed.

Claims (6)

  It has a structural unit derived from an initiator (a) having two or more active hydrogen groups per molecule, a structural unit derived from a dicarboxylic acid anhydride (b), and a structural unit derived from an alkylene oxide (c). And a pressure-sensitive adhesive obtained by curing a curable composition containing a silyl group-containing polymer (S) having a hydrolyzable silyl group at the molecular end.   The silyl group-containing polymer (S) is obtained by subjecting an initiator (a) having two or more active hydrogen groups per molecule to ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c). The pressure-sensitive adhesive according to claim 1, which is a silyl group-containing polymer (S1) obtained by introducing a hydrolyzable silyl group into a molecular terminal of the polyester ether polyol (Z).   The silyl group-containing polymer (S) is obtained by subjecting an initiator (a) having two or more active hydrogen groups per molecule to ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c). A polyol (Z) is obtained, and a polyol (A) containing the polyester ether polyol (Z) is reacted with a polyisocyanate compound (B) to obtain a prepolymer (P). The pressure-sensitive adhesive according to claim 1, which is a silyl group-containing polymer (S2) obtained by introducing a hydrolyzable silyl group.   The silyl group-containing polymer (S) is obtained by subjecting an initiator (a) having two or more active hydrogen groups per molecule to ring-opening polymerization of a dicarboxylic acid anhydride (b) and an alkylene oxide (c). A polyol (Z) is obtained, and a polyol (A) containing the polyester ether polyol (Z) and a polyisocyanate compound (B) are reacted to obtain a prepolymer (P), and a chain extender is added to the prepolymer (P). The pressure-sensitive adhesive according to claim 1, which is a silyl group-containing polymer (S3) obtained by reacting (C) to obtain a chain-extended polyurethane and introducing a hydrolyzable silyl group into the molecular terminal of the chain-extended polyurethane. body.   It has a structural unit derived from an initiator (a) having two or more active hydrogen groups per molecule, a structural unit derived from a dicarboxylic acid anhydride (b), and a structural unit derived from an alkylene oxide (c). And a silyl group-containing polymer (S) having a hydrolyzable silyl group at the molecular end. Forming a non-cured layer comprising a curable composition containing the silyl group-containing polymer (S) according to claim 5 on a substrate;
A pressure-sensitive adhesive comprising a step of curing the uncured layer in a state where the surface of the uncured layer opposite to the substrate is exposed or a release sheet is laminated on the surface. Sheet manufacturing method.

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