JP2022022973A5 - - Google Patents

Description

(Synthesis Example Z-2)
In an autoclave equipped with a stirrer and a temperature control device, 100 parts of terephthalic acid (TPA) as the first component, 27 parts of trimethylolpropane (TMP) as the second component, and 1,9- as the third component. 74 parts of nonanediol (ND) was charged. The esterification reaction was carried out by heating to 200 ° C. under a normal pressure nitrogen atmosphere and distilling the generated water out of the system. When the amount of distillate of the produced water decreased, 0.01 part of tetraisopropyl titanate was added, and the reaction was continued while reducing the pressure with a vacuum pump. A polyester polyol (HX-2) having a branching degree α of 0.35 was obtained.

(Synthesis Example Z-8)
1854 g of polycarbonate diol (trade name CD220, molecular weight 2011, hydroxyl value 55.8), trimethylolpropane 21 g, in a round bottom flask equipped with a stirrer, a thermometer, a nitrogen introduction tube, and a condenser. 126 g of pentaerythritol and 0.08 g of tetrabutyl titanate as a catalyst were charged. The mixture was heated under normal pressure with stirring. The reaction temperature was gradually increased, and after reaching 220 ° C., this temperature was maintained for 8 hours to carry out the reaction.
Sampling is performed at any time during the reaction, and the residual diol component (here, 1,6-hexanediol) and triol component (here, trimethylolpropane) are quantified by gas chromatography analysis, and the transesterification reaction is in an equilibrium state. After confirming that it became, the reaction was terminated.
As described above, a polycarbonate polyol (HX-S-6) having a number average molecular weight (Mn) of 1000, an average functional group series of primary , and a branching degree α of 0.05 was obtained. The raw material composition and the types and characteristics of the obtained polyols are shown in Table 1-1 and Table 1-2.

[Synthesis example of a solution of hydroxyl group-terminated urethane prepolymer (UPH)]
(Synthesis Example 1) One-stage dropping method (Method 1)
In a four-necked flask equipped with a stirrer, a reflux cooling tube, a nitrogen introduction tube, a thermometer, and a dropping funnel, 80.0 parts by mass of the active hydrogen group-containing compound (HX-S-1) and the active hydrogen group-containing compound ( HY-L-5) 20.0 parts by mass, 42.8 parts by mass of toluene, 0.020 parts by mass of dioctyl tin dilaurate and 0.008 parts by mass of tin 2-ethylhexanoate were charged and mixed as catalysts. Then, the content liquid was gradually heated to 80 ° C.
25.0 parts by mass of polyisocyanate (N-1) and 24.5 parts by mass of toluene were charged and mixed in the dropping funnel, and this mixed solution was added dropwise to a 4-necked flask over 1 hour. After the completion of the dropping, the reaction was carried out for 1 hour.
The ratio of the number of moles of isocyanate groups (NCO / H ratio) of the polyisocyanate (N) used in the reaction to the total number of moles of active hydrogen groups of all the active hydrogen group-containing compounds (H) used in the reaction is. It was 0.78.
After confirming the disappearance of the residual isocyanate group by infrared spectroscopic analysis (IR analysis), the content liquid was cooled to 40 ° C. to terminate the reaction. Finally, 0.56 parts by mass of acetylacetone was added.
As described above, a solution of a colorless and transparent hydroxyl-terminated urethane prepolymer (UPH-1) having a non-volatile content of 65% and a viscosity of 3200 cps was obtained. Table 2-1 shows the main compounding composition, NCO / H ratio, and Mw and Mn of the obtained hydroxyl group-terminated urethane prepolymer and the degree of branching α. In each example of Table 2-1 and Table 2-2, Table 3-1 and Table 3-2, and Table 4, the conditions not shown in the table were set as common conditions.

(Removability (60 ° C-90% RH, 24 hours))
A test piece having a width of 25 mm and a length of 100 mm was cut out from the obtained adhesive sheet. Then, in an atmosphere of 23 ° C.-50% RH, the release sheet was peeled off from the test piece, the exposed adhesive layer was attached to a caustic soda glass plate, and a 2 kg roll was reciprocated once from the top of the test piece for pressure bonding. Then, it was left for 24 hours in an atmosphere of 60 ° C. −90% RH, and air-cooled in an atmosphere of 23 ° C. −50% RH for 30 minutes. Then, in accordance with JIS Z 0237, the adhesive strength was measured using a tensile tester (Tensilon: manufactured by Orientec) under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. The lower the adhesive strength, the easier it is to peel off again. The evaluation criteria are as follows.
⊚: Less than 50 mN / 25 mm, excellent.
◯: 50 mN / 25 mm or more and less than 100 mN / 25 mm, good.
Δ: 100 mN / 25 mm or more and less than 300 mN / 25 mm, practically possible.
×: Over 300 mN / 25 mm, not practical.

(Heat resistance (150 ° C, 1 hour))
A test piece having a width of 25 mm and a length of 100 mm was cut out from the obtained adhesive sheet. Then, in an atmosphere of 23 ° C.-50% RH, the release sheet was peeled off from the test piece, the exposed adhesive layer was attached to a caustic soda glass plate, and a 2 kg roll was reciprocated once from the top of the test piece for pressure bonding. Then, it was left in an atmosphere of 150 ° C. for 1 hour, and air-cooled in an atmosphere of 23 ° C.-50% RH for 30 minutes. Then, in accordance with JIS Z 0237, the adhesive strength was measured using a tensile tester (Tensilon: manufactured by Orientec) under the conditions of a peeling speed of 300 mm / min and a peeling angle of 180 °. The lower the adhesive strength, the easier it is to peel off again. The evaluation criteria are as follows.
⊚: Less than 500 mN / 25 mm, excellent.
◯: 500 mN / 25 mm or more and less than 1000 mN / 25 mm, good.
Δ: 1000 mN / 25 mm or more and less than 3000 mN / 25 mm, practically possible.
×: Over 3000 mN / 25 mm, not practical.

In Synthesis Example 41, a comparative hydroxyl group terminal having a branching degree α of less than 0.2 is used by using an active hydrogen group-containing compound (HX) having a branching degree α of 0.5 or less and a polyisocyanate (N). Urethane prepolymer (UPC-1) was obtained.
In Synthesis Example 42, a comparative hydroxyl group terminal having a branching degree α of more than 0.8 using an active hydrogen group-containing compound (HY) having a branching degree α of more than 0.5 and a polyisocyanate (N). Urethane prepolymer (UPC-2) was obtained.
In Comparative Examples 1 and 2 using the hydroxyl group-terminated urethane prepolymer (UPC-1) or (UPC-2) for comparison, the obtained adhesive sheet had initial curability and removability (60 ° C.-90% RH). ) Was poor. The evaluation results were also poor for many other evaluation items.

Claims (8)

A hydroxyl group-terminated urethane prepolymer (UPH) which is a reaction product of one or more active hydrogen group-containing compounds (H) having a plurality of active hydrogen groups in one molecule and one or more polyisocyanates (N).
A pressure-sensitive adhesive containing the polyfunctional isocyanate compound (I).
The active hydrogen group-containing compound (H) of one or more kinds contains 50% by mass or more of the active hydrogen group-containing compound (HY) having a branching degree of more than 0.5 as measured by the GPC-MALS method.
The hydroxyl group-terminated urethane prepolymer (UPH) is a pressure-sensitive adhesive having a branching degree of more than 0.6 and 0.8 or less as measured by the GPC-MALS method. The active hydrogen group-containing compound (H) of one or more kinds contains 50% by mass or more of the active hydrogen group-containing compound (HY) having a branching degree of more than 0.5 as measured by the GPC-MALS method.
The pressure-sensitive adhesive according to claim 1, wherein the hydroxyl group-terminated urethane prepolymer (UPH) has a branching degree of 0.7 to 0.8 as measured by the GPC-MALS method. Claimed that one or more active hydrogen group-containing compounds (H) contain 50% by mass or more of an active hydrogen group-containing compound (HY-L) having a branching degree of more than 0.6 as measured by the GPC - MALS method. The pressure-sensitive adhesive according to 1 or 2 . One or more active hydrogen group-containing compounds (H) contain 50% by mass or more and less than 100% by mass of the active hydrogen group-containing compound (HY) having a branching degree of more than 0.5 as measured by the GPC-MALS method. The adhesion according to any one of claims 1 to 3, wherein the active hydrogen group-containing compound (HX) having a branching degree of 0.5 or less as measured by the GPC-MALS method is contained in an amount of more than 0% by mass and less than 50% by mass. Agent. The pressure-sensitive adhesive according to any one of claims 1 to 4 , further comprising a plasticizer. The pressure-sensitive adhesive according to any one of claims 1 to 5 , further comprising an antistatic agent. The adhesion according to any one of claims 1 to 6 , further comprising one or more antioxidants selected from the group consisting of antioxidants, hydrolysis resistant agents, ultraviolet absorbers, and light stabilizers. Agent. A pressure-sensitive adhesive sheet comprising a base material sheet and a pressure-sensitive adhesive layer made of a cured product of the pressure-sensitive adhesive according to any one of claims 1 to 7 .