JPWO2017104267A1 - Polyurethane composition and sheet - Google Patents

Abstract

The problem to be solved by the present invention is to provide a polyurethane composition from which a sheet excellent in step following property, substrate adhesion, sheet holding property, and stain resistance can be obtained. The present invention provides a bifunctional polyol (a-1) and a compound (a-2) having three hydroxyl groups in an equivalent ratio [(a-1) / (a-2)] of 0.7 to 100. The present invention provides a polyurethane composition characterized by containing a polyol (a) contained as a raw material and containing a hydroxyl group-containing polyurethane (A), a crosslinking agent (B), and an organic solvent (C). Moreover, this invention provides the sheet | seat characterized by formed with the said polyurethane composition. A sheet formed from the polyurethane composition of the present invention is excellent in step following ability, substrate adhesion, sheet retention, and stain resistance.

Description

  The present invention relates to a polyurethane composition from which a sheet excellent in step following property, substrate adhesion, sheet holding property, and stain resistance can be obtained.

  Silicon films having excellent heat resistance are widely used in heat conductive sheets, surface protective films, and the like used in electronic devices and electronic parts such as displays, LED lighting, transistors, and capacitors.

  In the silicon film, not only heat resistance but also various properties such as flexibility, thermal conductivity, and slight adhesiveness are required depending on the application to be used, and diversification of required properties is progressing. . On the other hand, the alternative examination using the polyurethane composition which can respond to various request | requirements by resin design has begun (for example, refer patent document 1).

  Among these, in applications where electronic devices, electronic parts, and the like are coated, it is desired to develop a polyurethane composition that can form a sheet having excellent step followability that can follow fine steps on the surface. However, the actual situation is that the desired step following ability has not yet been obtained.

  Furthermore, when used for the manufacture of electronic equipment and electronic parts, good processability is also required. One example of processing in which a sheet formed of a polyurethane composition is used in a manufacturing process of an electronic component or the like is given. The sheet is first slitted from a wide roll to a desired width, then electronic parts are temporarily fixed on the sheet, and each part is cut into a shape, and the parts are separated from the sheet after completion of processing. The processing method to do is mentioned.

  In this case, the sheet processing suitability required for the sheet, for example, in the case of punching or slit processing, the cured product layer of the polyurethane composition is peeled off from the substrate by pressing of the processing blade, the paste powder of the cured product layer or Excellent base material adhesion that does not generate residue, and the cured product layer does not stick to the processing blade or the cured product layer protrudes from the end surface of the sheet, and the punched sheet and the sheet outer periphery remain bonded. It is required to have excellent sheet holding properties to prevent the above. Although improving the sheet processing suitability can reduce the number of cleanings of the processing blade and improve the yield and work efficiency, it is difficult to achieve both substrate adhesion and sheet retention. It was.

JP 2010-235734 A

  The problem to be solved by the present invention is to provide a polyurethane composition from which a sheet excellent in step following property, substrate adhesion, sheet holding property, and stain resistance can be obtained.

  The present invention provides a bifunctional polyol (a-1) and a compound (a-2) having three hydroxyl groups in an equivalent ratio [(a-1) / (a-2)] of 0.7 to 100. A polyurethane composition comprising a polyurethane (A) having a hydroxyl group, a crosslinking agent (B), and an organic solvent (C) using the contained polyol (a) as a raw material is provided. Moreover, this invention provides the sheet | seat characterized by formed with the said polyurethane composition.

  A sheet formed from the polyurethane composition of the present invention is excellent in step following ability, substrate adhesion, sheet retention, and stain resistance.

  The polyurethane composition of the present invention comprises a bifunctional polyol (a-1) and a compound (a-2) having three hydroxyl groups in an equivalent ratio [(a-1) / (a-2)] of 0.7 to A polyol (a) contained in a range of 100 is used as a raw material, and contains a polyurethane (A) having a hydroxyl group, a crosslinking agent (B), and an organic solvent (C).

  As said polyurethane (A), the bifunctional polyol (a-1) and the compound (a-2) which has three hydroxyl groups are used as a raw material, and those equivalent ratio [(a-1) / (a-2) )] Is in the range of 0.7-100. Thereby, since a softness | flexibility and cohesion force can be controlled in an appropriate range and a crosslinking density can be controlled, the sheet | seat excellent in level | step difference followability, base-material adhesiveness, sheet | seat retention, and stain resistance is obtained. If the equivalent ratio is less than 0.7, the cohesive strength of the polyurethane itself is too high and / or the distance between crosslinks is too short, so that the flexibility and elongation of the sheet is insufficient, and the desired step following property is achieved. If the substrate adhesion is not obtained, and if it exceeds 100, the distance between crosslinks becomes too large, the sheet holding property cannot be obtained, or the adhesive residue or transfer due to the increase in adhesive force during the durability test And the desired stain resistance cannot be obtained. The equivalence ratio is preferably in the range of 1 to 100, more preferably in the range of 1 to 80, since further excellent processability and stain resistance can be obtained.

  In addition, the said equivalence ratio shows a normal equivalence ratio, for example, when manufacturing the polyurethane (A) by charging the said bifunctional polyol (a-1) and the compound (a-2) which has three hydroxyl groups collectively. Shows the equivalent ratio calculated from the functional group equivalent of the bifunctional polyol (a-1) / functional group equivalent of the compound (a-2) having three hydroxyl groups. When the bifunctional polyol (a-1) and the compound (a-2) having three hydroxyl groups are reacted stepwise, for example, first, the bifunctional polyol (a-1) and a polyisocyanate (a) described later are used. When the compound (a-2) having three hydroxyl groups is further reacted after reacting with -3), the equivalent ratio calculated from each [NCO / OH] described later is shown.

  Specifically, as the polyurethane (A), for example, a polyol (a) containing the bifunctional polyol (a-1) and a compound (a-2) having three hydroxyl groups and a polyisocyanate (a-3). ) And the reaction product can be used.

  Examples of the bifunctional polyol (a-1) include polyoxyethylene glycol, polyoxypropylene glycol, polyoxytetramethylene glycol, polyoxyethylene polyoxypropylene glycol, polyoxyethylene polyoxytetramethylene glycol, and polyoxypropylene. Polyether diols such as polyoxytetramethylene glycol; polycarbonate diol, polyester diol, acrylic diol, polybutadiene diol, hydrogenated polybutadiene diol, and the like can be used. These bifunctional polyols may be used alone or in combination of two or more. Among these, in applications where transparency is required for the sheet, in order to suppress haze generation derived from the crystallinity of the polyol, it is relatively versatile, and from the viewpoint of easy selection of a low glass transition temperature product, polyether diol, It is preferable to use one or more polyols selected from the group consisting of polycarbonate diols and polyester diols.

  The number average molecular weight of the bifunctional polyol (a-1) is preferably in the range of 100 to 20,000, more preferably in the range of 150 to 10,000, from the viewpoint of obtaining even better cohesion. preferable. In addition, the number average molecular weight of the said bifunctional polyol (a-1) shows the value measured on condition of the following by gel permeation chromatography (GPC) method.

Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series.
"TSKgel G5000" (7.8 mm ID x 30 cm) x 1 "TSKgel G4000" (7.8 mm ID x 30 cm) x 1 "TSKgel G3000" (7.8 mm ID x 30 cm) x 1 “TSKgel G2000” (7.8 mm ID × 30 cm) × 1 detector: RI (differential refractometer)
Column temperature: 40 ° C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL / min Injection amount: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%)
Standard sample: A calibration curve was prepared using the following standard polystyrene.

(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-1" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

  Examples of the compound (a-2) having three hydroxyl groups include propylene oxide adducts such as an adduct of glycerin and propylene oxide, an adduct of trimethylolpropane and propylene oxide; propylene using glycerin as an initiator. After adding oxide, further added ethyne oxide at its end, added glycerin as an initiator, added a mixture of propylene oxide and ethylene oxide, after adding propylene oxide using trimethylolpropane as an initiator, Propylene oxide and ethylene oxide adducts such as those obtained by further adding ethyne oxide to the end, or those obtained by adding a mixture of propylene oxide and ethylene oxide using trimethylolpropane as an initiator. Polyoxyethylene polyoxypropylene triol can be used. These compounds having three hydroxyl groups may be used alone or in combination of two or more. Among these, flexibility is imparted to the polyurethane composition, and even better wettability to the adherend, adhesion to the substrate, and sheet retention are obtained. From the viewpoint of further improvement, it is preferable to use the polyoxyethylene polyoxypropylene triol.

  The number average molecular weight of the compound (a-2) having three hydroxyl groups is in the range of 1,500 to 10,000 from the viewpoint of obtaining good flexibility, substrate adhesion, and sheet retention. It is preferable that it is in the range of 2,000 to 5,000. In addition, the number average molecular weight of the said compound (a-2) which has the said 3 hydroxyl group shows the value obtained by measuring similarly to the said bifunctional polyol (a-1).

  In addition to the bifunctional polyol (a-1) and the compound (a-2) having three hydroxyl groups, the polyol (a) may be a compound having four or more hydroxyl groups or a so-called chain extension, if necessary. An agent or the like may be used in combination.

  Examples of the polyisocyanate (a-3) include aromatic polyisocyanates such as xylylene diisocyanate, phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate; hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, 4 Aliphatic or alicyclic polyisocyanates such as 4,4'-dicyclohexylmethane diisocyanate and tetramethylxylylene diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more.

  As a manufacturing method of the said polyurethane (A), both are made to react so that the molar ratio of the hydroxyl group which a polyol (a) has may be excess with respect to the molar ratio of the isocyanate group which polyisocyanate (a-3) has, for example. A method is mentioned. In addition, you may perform the said reaction in the organic solvent (C) mentioned later. The polyol (a) may be charged all at once, or may be charged in two or more times while controlling the reaction. Further, for example, the bifunctional polyol (a-1) and the polyisocyanate (a-3) are previously prepared. And the like, and then a method of reacting the compound (a-2) having three hydroxyl groups may be used. In any case, the molar ratio (NCO / OH) between the hydroxyl group of the polyol (a) and the isocyanate group of the polyisocyanate (a-3) is as follows: From the viewpoint of mechanical strength, it is preferably in the range of 0.3 to 0.99, more preferably in the range of 0.5 to 0.99.

  The weight average molecular weight of the polyurethane (A) is preferably in the range of 10,000 to 700,000, and preferably in the range of 30,000 to 500,000 from the viewpoint that both flexibility and mechanical strength can be achieved at a high level. A range is more preferable. In addition, the weight average molecular weight of the said polyurethane (A) shows the value measured similarly to the number average molecular weight of the said bifunctional polyol (a-1).

  As the content of the hydroxyl group in the polyurethane (A), the crosslink density with the crosslinking agent (B) described later and the distance between crosslinks can be optimized, so that even better substrate adhesion and sheet retention can be obtained. From the viewpoint, the range is preferably 0.005 to 0.3 mol / kg, more preferably 0.01 to 0.28 mol / kg, and particularly preferably 0.04 to 0.25 mol / kg. In addition, content of the hydroxyl group in the said polyurethane (A) shows content of the hydroxyl group which occupies in the said raw material with respect to the total mass of each raw material which comprises the said polyurethane (A).

  As the content of the urethane bond in the polyurethane (A), the cohesive force can be controlled, and more excellent substrate adhesion, sheet retention, and stain resistance can be obtained. The range of 0.2 to 10 mol / kg is more preferable, the range of 0.4 to 5 mol / kg is still more preferable, and the range of 0.5 to 5 mol / kg is particularly preferable. In addition, content of the urethane bond in the said polyurethane (A) shows content of the urethane bond structure which occupies in the said raw material with respect to the total mass of each raw material which comprises the said polyurethane (A).

  As said crosslinking agent (B), a polyisocyanate crosslinking agent, an epoxy crosslinking agent, a melamine crosslinking agent etc. can be used, for example. These crosslinking agents may be used alone or in combination of two or more. Among these, by reacting with the hydroxyl group of the polyurethane (A) to form a three-dimensional crosslink, good mechanical strength, step following ability, substrate adhesion, sheet retention, and stain resistance can be obtained. From the viewpoint, it is preferable to use a polyisocyanate crosslinking agent.

  Examples of the polyisocyanate crosslinking agent include tolylene diisocyanate, chlorophenylene diisocyanate, hexamethylene diisocyanate, tetramethylene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and xylylene diisocyanate; hexamethylene diisocyanate trimethylolpropane Adduct, trimethylolpropane adduct of tolylene diisocyanate, trimethylolpropane adduct of isophorone diisocyanate, trimethylolpropane adduct of xylylene diisocyanate, isocyanurate of hexamethylene diisocyanate, nurate of tolylene diisocyanate, isophorone dii Isocyanurate cyanate, or the like can be used isocyanurate of xylylene diisocyanate. These crosslinking agents may be used alone or in combination of two or more.

  The amount of the crosslinking agent (B) used is 0. 0 parts by mass with respect to 100 parts by mass of the polyurethane (A) (solid content) from the viewpoint that the step following ability, the substrate adhesion and the sheet retention can be achieved at a high level. The range is preferably from 01 to 20 parts by mass, more preferably from 0.05 to 15 parts by mass, and still more preferably from 0.1 to 10 parts by mass.

  The organic solvent (C) is used for improving the production stability of the polyurethane (A) and the coating property of the polyurethane composition, and examples thereof include esters such as ethyl acetate, methyl acetate, and butyl acetate. Solvent; Ketone solvent such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Aliphatic hydrocarbon solvent such as heptane, hexane, cyclohexane and methylcyclohexane; Aromatic hydrocarbon solvent such as toluene, o-xylene, m-xylene and p-xylene Alcohol solvents such as methanol, ethanol, isopropyl alcohol, isobutanol, sec-butanol, and tertiary butanol can be used. These organic solvents may be used alone or in combination of two or more.

  As the usage-amount of the said organic solvent (C), it is preferable that it is the range of 20-200 mass parts with respect to 100 mass parts of said polyurethanes (A) from the point of coating property, The range of 40-180 mass parts is preferable. Is more preferable.

  The polyurethane composition of the present invention contains the polyurethane (A), the crosslinking agent (B), and the organic solvent (C) as essential components, and further contains other additives as necessary. Also good.

  Examples of other additives include carbodiimide compounds, antioxidants, plasticizers, rust inhibitors, thixotropic agents, dispersants, sensitizers, urethanization catalysts, polymerization inhibitors, leveling agents, tackifiers, A foam stabilizer or the like can be used. These additives may be used alone or in combination of two or more. Among these, it is preferable to contain a carbodiimide compound from the viewpoint that much more excellent stain resistance can be obtained.

  Examples of the carbodiimide compound include N, N′-dicyclohexylcarbodiimide, N, N′-diisopropylcarbodiimide, 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide, and N- [3- (dimethylamino) propyl]. -N'-ethylcarbodiimide, N- [3- (dimethylamino) propyl] -N'-ethylcarbodiimide methiodide, N-tert-butyl-N'-ethylcarbodiimide, N-cyclohexyl-N '-(2- Carbodiimide compounds such as morpholinoethyl) carbodiimide meso-p-toluenesulfonate, N, N′-di-tert-butylcarbodiimide, N, N′-di-p-tolylcarbodiimide; polyisocyanates in the presence of carbodiimidization catalysts Obtained by the condensation reaction of Recarbodiimide or the like can be used. These carbodiimide compounds may be used alone or in combination of two or more. Among these, it is preferable to use a carbodiimide compound having an isocyanate group because it reacts with the hydroxyl group of the polyurethane (A) to obtain further excellent stain resistance.

  Examples of the carbodiimide compound include “carbodilite V-02”, “carbodilite V-02-L2”, “carbodilite V-04”, “carbodilite V-05”, “carbodilite V-07”, “carbodilite V-09”. ”,“ Carbodilite E-01 ”,“ Carbodilite E-02 ”,“ Carbodilite E-03A ”,“ Carbodilite E-04 ”(manufactured by Nisshinbo Chemical Co., Ltd.) and the like are commercially available.

  The amount used in the case of using the carbodiimide compound is preferably in the range of 0.1 to 7 parts by mass with respect to 100 parts by mass of the polyurethane (A) from the viewpoint of obtaining further excellent stain resistance. The range of 0.5 to 5 parts by mass is more preferable.

  As a method for producing the polyurethane composition used in the present invention, for example, the crosslinking agent (B) is added to the mixture in which the polyurethane (A) is dissolved in the organic solvent (C). The method of adding an agent and mixing is mentioned.

  Examples of a method for forming a sheet from the polyurethane composition of the present invention include a method in which the polyurethane composition is coated on a plastic substrate, and dried and cured.

  Examples of the plastic substrate include polyester such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, polyolefin, polyacrylate, polyvinyl chloride, polyethylene, polypropylene ethylene vinyl alcohol, polyurethane, polyamide, and polyimide. Sheet or film can be used. The surface of these plastic substrates may be subjected to mold release treatment, antistatic treatment, corona treatment and the like. Moreover, as thickness of these said plastic base materials, it is the range of 10-200 micrometers, for example.

  Examples of the method for applying the polyurethane composition to the plastic substrate include a coating method using a roll coater, a gravure coater, a reverse coater, a spray coater, an air knife coater, a die coater and the like.

  The thickness of the sheet after drying the organic solvent (C) is, for example, in the range of 5 to 100 μm.

  Examples of the method for drying the polyurethane composition after coating the polyurethane composition on the plastic substrate include a method of drying at 50 to 120 ° C. for 30 seconds to 30 minutes. Moreover, you may age at the temperature of 30 degreeC-50 degreeC, for example from the point which accelerates | stimulates hardening reaction after drying.

  As described above, the polyurethane composition of the present invention has excellent step following ability, substrate adhesion, sheet retention, and stain resistance. Therefore, the sheet | seat obtained from the said polyurethane composition can be used conveniently as a heat conductive sheet, a surface protection sheet, a rough surface adhesive sheet, etc.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, polyoxypropylene glycol (number average molecular weight; 2,000, hereinafter abbreviated as “PPG2000”) 1,550 parts by mass, hexamethylene diisocyanate ( (Hereinafter abbreviated as “HDI”) is 165 parts by mass, dioctyltin dilaurate is 0.03 parts by mass, polyoxyethylene polyoxypropylene triol (number average molecular weight; 3,000, hereinafter abbreviated as “EOPO3000”). 800 parts by mass and 1,540 parts by mass of ethyl acetate were charged into a separable flask and heated to 75 ° C. After confirming that the isocyanate group content became the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, the content was cooled and nonvolatile content: 62 mass%, hydroxyl group content: 0.16 mol / kg, Weight average molecular weight: 112,700, polyoxyalkylene content: 15.4 mol / kg, molar ratio of oxyethylene structure to oxypropylene structure; 9/102, urethane bond content: 0.78 mol / kg polyurethane (A-1) A solution was obtained. To 100 parts by mass of this polyurethane (A-1) solution, 3.6 parts by mass of an isocyanurate body of hexamethylene diisocyanate (hereinafter abbreviated as “HDI nurate”) is added as a crosslinking agent immediately before producing the sheet. A polyurethane composition was obtained. [(A-1) / (a-2)] is 1.9.

[Example 2]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 990 parts by mass of polyoxypropylene glycol (number average molecular weight; 2,000, hereinafter abbreviated as “PPG2000”), hexamethylene diisocyanate (hereinafter, , Abbreviated as “HDI”), 150 parts by mass of polyoxyethylene polyoxypropylene triol (number average molecular weight; 3,000, hereinafter abbreviated as “EOPO3000”), 1,460 parts by mass of dioctyltin dilaurate. 0.2 parts by mass and 1,730 parts by mass of ethyl acetate were charged into a separable flask and heated to 70 ° C. for reaction. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid. Nonvolatile content: 60% by mass, viscosity: 4,100 mPa · s, hydroxyl group content 0.23 mol / kg, weight average molecular weight; 84,000, polyoxyalkylene content; 16.6 mol / kg, molar ratio of oxyethylene structure to oxypropylene structure; 15/85, content of urethane bond : A polyurethane (A-2) solution of 0.69 mol / kg was obtained. 5 parts by mass of hexamethylene diisocyanate nurate (hereinafter abbreviated as “HDI nurate”) as a crosslinking agent with respect to 100 parts by mass of the polyurethane (A-2) solution based on the solid content of the polyurethane (A-2). Partly blended to obtain a polyurethane composition. In addition, [(a-1) / (a-2)] is 0.7.

[Example 3]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 1760 parts by mass of polyoxypropylene glycol (number average molecular weight: 10,000, hereinafter abbreviated as “PPG10000”) and 40 parts by mass of HDI. Parts, 230 parts by mass of EOPO3000, 0.2 parts by mass of dioctyltin dilaurate and 1,095 parts by mass of ethyl acetate were charged into a separable flask and reacted by heating to 70 ° C. The completion of the reaction was confirmed when the isocyanate group content was calculated from the charged amount by titration with dibutylamine and hydrochloric acid. The nonvolatile content: 65% by mass, viscosity: 12,000 mPa · s, hydroxyl group content Amount: 0.08 mol / kg, weight average molecular weight; 120,000, polyoxyalkylene content; 16.6 mol / kg, molar ratio of oxyethylene structure to oxypropylene structure; 5/95, content of urethane bond : A polyurethane (A-3) solution of 0.23 mol / kg was obtained. With respect to 100 parts by mass of the polyurethane (A-3) solution, 10 parts by mass of HDI nurate as a crosslinking agent with respect to the solid content of the polyurethane (A-3) was blended to obtain a polyurethane composition. [(A-1) / (a-2)] is 1.5.

[Example 4]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 1,560 parts by mass of PPG 3000, 110 parts by mass of isophorone diisocyanate (hereinafter abbreviated as “IPDI”), 680 parts by mass of EOPO 3000, 0.03 parts by mass of dioctyltin dilaurate and 995 parts by mass of ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by a titration method with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 72% by mass, viscosity: 6,800 mPa · s. , Hydroxyl content; 0.14 mol / kg, weight average molecular weight; 46,000, polyoxyalkylene content; 15.4 mol / kg, molar ratio of oxyethylene structure to oxypropylene structure; 1/15, urethane Content of bond: A polyurethane (A-4) solution having a mol content of 0.56 mol / kg was obtained. Immediately before producing the sheet, 3.3 parts by mass of HDI nurate was added to 100 parts by mass of this polyurethane (A-4) solution to obtain a polyurethane composition. [(A-1) / (a-2)] is 1.5.

[Example 5]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 200 parts by mass of polyoxypropylene glycol (number average molecular weight; 400, hereinafter abbreviated as “PPG400”), 85 parts by mass of HDI, and EOPO 3000 308 parts by mass, dioctyltin dilaurate 0.03 parts by mass and ethyl acetate in a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 53% by mass; hydroxyl group content; A polyurethane (A-5) solution having 029 mol / kg, weight average molecular weight; 109,000, urethane bond content: 3.3 mol / kg was obtained. Immediately before producing the sheet, 2.8 parts by mass of HDI nurate was added to 100 parts by mass of this polyurethane (A-5) solution to obtain a polyurethane composition. [(A-1) / (a-2)] is 3.3.

[Example 6]
1,015 mass parts of polyester diol (“MX2420” manufactured by DIC Corporation, number average molecular weight; 2000, hereinafter abbreviated as “PEs”) in a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer. In addition, 105 parts by mass of HDI, 450 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, and ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 44% by mass, hydroxyl group content; A polyurethane (A-6) solution having 12 mol / kg, weight average molecular weight; 86,900, urethane bond content: 0.8 mol / kg was obtained. Immediately before producing the sheet, 1.6 parts by mass of HDI nurate was added to 100 parts by mass of this polyurethane (A-6) solution to obtain a polyurethane composition. [(A-1) / (a-2)] is 2.3.

[Example 7]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 1,202 parts by mass of polyoxypropylene glycol (number average molecular weight; 200, hereinafter abbreviated as “PPG200”), and HDI of 1,017. Part by mass, 163 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, and ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by a titration method with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 64% by mass, hydroxyl group content; A polyurethane (A-7) solution having 029 mol / kg, weight average molecular weight; 210,700, urethane bond content: 5.1 mol / kg was obtained. To 100 parts by mass of this polyurethane (A-7) solution, 0.7 part by mass of HDI nurate was added as a crosslinking agent immediately before producing the sheet to obtain a polyurethane composition. [(A-1) / (a-2)] is 73.7.

[Example 8]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 1,002 parts by mass of PPG2000, 85 parts by mass of HDI, 18 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, ethyl acetate Was charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 71% by mass; hydroxyl group content: 0. A polyurethane (A-8) solution having 007 mol / kg, weight average molecular weight; 451,500, and urethane bond content: 0.9 mol / kg was obtained. To 100 parts by mass of this polyurethane (A-8) solution, 0.7 part by mass of HDI nurate was added as a crosslinking agent immediately before producing the sheet to obtain a polyurethane composition. [(A-1) / (a-2)] is 55.7.

[Example 9]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, polycarbonate diol (“Duranate T5652” manufactured by Asahi Kasei Chemicals Corporation, number average molecular weight; 2000, hereinafter abbreviated as “PC”) is 1,015. Part by mass, 105 parts by mass of HDI, 450 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, and ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 49% by mass; hydroxyl group content; A polyurethane (A-9) solution having 12 mol / kg, weight average molecular weight; 90,500, urethane bond content: 0.8 mol / kg was obtained. Immediately before producing the sheet, 1.6 parts by mass of HDI nurate was added to 100 parts by mass of this polyurethane (A-9) solution to obtain a polyurethane composition. [(A-1) / (a-2)] is 2.3.

[Example 10]
In Example 1, it replaced with 3.6 mass parts of HDI nurate, and implemented except having changed the trimethylol propane adduct body (henceforth "HDI-TMP") of hexamethylene diisocyanate to 4.7 mass parts. A polyurethane composition was obtained in the same manner as in Example 1.

[Example 11]
In Example 6, instead of 3.6 parts by mass of HDI nurate, the trimethylolpropane adduct of toluene diisocyanate (hereinafter abbreviated as “TDI-TMP”) was changed to 4.7 parts by mass. 4 to obtain a polyurethane composition.

[Example 12]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, polyoxymethylene glycol (number average molecular weight; 1000, hereinafter abbreviated as “PTMG1000”) is 1,032 parts by mass, and HDI is 260 parts by mass. Then, 1820 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, and ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content: 44% by mass, hydroxyl group content; A polyurethane (A-10) solution having 11 mol / kg, weight average molecular weight; 75,080, urethane bond content: 1.4 mol / kg was obtained. Immediately before producing the sheet, 1.5 parts by mass of HDI nurate was added to 100 parts by mass of this polyurethane (A-10) solution to obtain a polyurethane composition. [(A-1) / (a-2)] is 1.1.

[Example 13]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, polyoxyethylene glycol (number average molecular weight; 200, hereinafter abbreviated as “PEG200”) is 1,025 parts by mass, and HDI is 194 parts by mass. Then, 449 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, and ethyl acetate were charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content; 52% by mass; hydroxyl group content; A polyurethane (A-11) solution having 24 mol / kg, weight average molecular weight; 36,200, urethane bond content: 1.0 mol / kg was obtained. To 100 parts by mass of this polyurethane (A-11) solution, 3.3 parts by mass of HDI nurate as a cross-linking agent was added immediately before manufacturing the sheet to obtain a polyurethane composition. In addition, [(a-1) / (a-2)] is 22.8.

[Example 14]
In Example 6, 1 part by mass of Nisshinbo Carbodiimide Compound “Carbodilite V-05” (hereinafter abbreviated as “V-05”) is added to 100 parts by mass of the nonvolatile content of polyurethane (A-6). A polyurethane composition was obtained in the same manner as in Example 6 except that.

[Comparative Example 1]
In a reaction vessel equipped with a stirrer, a reflux condenser, a nitrogen inlet tube, and a thermometer, 1,558 parts by mass of PPG3000, 152 parts by mass of HDI, 1,641 parts by mass of EOPO3000, 0.03 parts by mass of dioctyltin dilaurate, Ethyl acetate was charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by a titration method with dibutylamine and hydrochloric acid, and the reaction was cooled to a non-volatile content; 76% by mass; hydroxyl group content; A polyurethane (A′-1) solution having 23 mol / kg, weight average molecular weight; 51,160, urethane bond content: 0.54 mol / kg was obtained. To 100 parts by mass of this polyurethane (A′-1) solution, 5.6 parts by mass of HDI nurate as a cross-linking agent was added immediately before manufacturing the sheet to obtain a polyurethane composition. [(A-1) / (a-2)] is 0.6.

[Comparative Example 2]
In a reaction vessel equipped with a stirrer, reflux condenser, nitrogen inlet tube and thermometer, PPG2000 is 1,023 parts by mass, HDI is 84 parts by mass, EOPO3000 is 10 parts by mass, dioctyltin dilaurate is 0.03 parts by mass, ethyl acetate Was charged into a separable flask and heated to 75 ° C. The completion of the reaction was confirmed when the isocyanate group content reached the content calculated from the charged amount by titration with dibutylamine and hydrochloric acid, and the mixture was cooled and cooled to nonvolatile content; 55% by mass; hydroxyl group content; Polyurethane (A′-2) solution having 004 mol / kg, weight average molecular weight; 207,220, urethane bond content: 0.92 mol / kg was obtained. To 100 parts by mass of this polyurethane (A′-2) solution, 8.1 parts by mass of HDI nurate as a cross-linking agent was added immediately before manufacturing the sheet to obtain a polyurethane composition. [(A-1) / (a-2)] is 102.3.

[Sheet Processing Method 1]
The polyurethane obtained in Examples and Comparative Examples was applied to the surface of a polyethylene terephthalate film having a thickness of 50 μm which had been subjected to a release treatment so that the film thickness after drying would be 100 μm and dried at 80 ° C. for 3 minutes. It was. A 38 μm-thick polyethylene terephthalate film whose surface was subjected to a release treatment was bonded to this, and was cured at 40 ° C. for 3 days to obtain a sheet.

[Sheet processing method 2]
The polyurethane obtained in Examples and Comparative Examples was applied to the surface of a 50 μm thick polyethylene terephthalate film so that the film thickness after drying was 100 μm, and dried at 80 ° C. for 3 minutes. A 38 μm-thick polyethylene terephthalate film whose surface was subjected to a release treatment was bonded to this, and was cured at 40 ° C. for 3 days to obtain a sheet.

[Evaluation method of step following ability]
A sheet obtained by cutting the sheet obtained in [Sheet Processing Method 1] into a size of 30 mm × 30 mm was used as a test piece. The test piece was cut to a size of 20 mm × 20 mm and attached to a glass plate on which a polyethylene terephthalate (PET) film having a thickness of 25 μm was placed, and the gap between the PET film and the test piece was visually observed. Evaluation was performed as follows.
“◎”: No gap between the PET film and the test piece (complete tracking)
“◯”: A part of air enters between the PET film and the test piece, and the float is generated (partly following)
"X": Air exists around the PET film, and the test piece is floating (complete peeling)

[Evaluation method of substrate adhesion]
A sheet obtained by cutting the sheet obtained in [Sheet Processing Method 2] into a size of 30 mm × 30 mm was used as a test piece. The release PET film was peeled from the test piece, this was cut with a cross cutter from the polyurethane layer side, and the generation of powder of the polyurethane layer when it was rubbed 10 times with a finger and the presence or absence of dropping were visually observed. It was evaluated as follows.
“◎”: There is no generation or loss of powder in the polyurethane layer.
“◯”: The polyurethane layer is slightly fuzzy, but there is no skipping of the glue powder.
“Δ”: A small amount of powder in the polyurethane layer was generated, but there was no dropout.
“×”: A large amount of powder of the polyurethane layer can be confirmed, and dropping is also confirmed.

[Evaluation method of sheet retention]
A sheet obtained by cutting the sheet obtained in [Sheet Processing Method 2] into a size of 100 mm × 150 mm was used as a test piece. From the PET film side, without cutting the release PET film, only PET film and polyurethane layer are punched by 40 pieces of 4 pieces at 5mm intervals with a width of 10mm and a length of 100mm. It was confirmed whether the polyurethane layer adhered. Then, it peeled from the PET film side for every sheet | seat, and visually observed whether it was able to cut | disconnect neatly and the polyurethane layer did not protrude, and evaluated as follows.
“◎”: No polyurethane adhered to the punching blade, and the polyurethane layer was separated without protruding.
“◯”: Since polyurethane adheres to the punching blade, it is necessary to wipe the blade once or twice. The polyurethane layer can be separated without protruding.
“△”: Since polyurethane adheres to the cutting blade, it is necessary to wipe the blade 3 to 5 times. The polyurethane layer shows a slight amount of paste.
“×”: Since polyurethane adheres widely to the blade of the punching blade, it is necessary to wipe the blade six times or more. The overhang of the polyurethane layer is confirmed, or the sheet cannot be separated.

[Contamination resistance evaluation method]
A sheet obtained by cutting the sheet obtained in [Sheet Processing Method 2] into a size of 30 mm × 30 mm was used as a test piece, from which release PET was peeled off and attached to a glass plate. At that time, air bubbles were introduced between the sheet and the glass plate. The test piece was left for 72 hours at 60 ° C. and 90% humidity. Then, after leaving for 24 hours in an environment of 23 ° C., the sheet was peeled off from the glass plate by hand, irradiated with LED light from the lower part of the glass plate, and the contamination status was observed visually and with a microscope and evaluated as follows. did.
“◎”: There is no contamination on the glass plate.
“O”: Contamination is confirmed on a part of the glass plate with a microscope. (Not visible)
“Δ”: Contamination is visually confirmed on a part of the glass plate.
“X”: Contamination on the entire surface of the glass plate or falling off of the cured product of the polyurethane composition is confirmed.

  It was found that the sheet formed from the polyurethane composition of the present invention has excellent step following ability, substrate adhesion, sheet retention, and stain resistance.

  On the other hand, Comparative Example 1 is an aspect in which the equivalent ratio of the bifunctional polyol (a-1) and the compound (a-2) having three hydroxyl groups is lower than the range defined in the present invention, The stain resistance was poor.

  Comparative Example 2 is an embodiment in which the equivalent ratio of the bifunctional polyol (a-1) and the compound (a-2) having three hydroxyl groups exceeds the range specified in the present invention. Adhesion was poor.

Claims (5)

A polyol containing a bifunctional polyol (a-1) and a compound (a-2) having three hydroxyl groups in an equivalent ratio [(a-1) / (a-2)] in the range of 0.7 to 100 ( A polyurethane composition comprising a) a raw material, a hydroxyl group-containing polyurethane (A), a crosslinking agent (B), and an organic solvent (C). The polyurethane composition according to claim 1, wherein the content of the hydroxyl group in the polyurethane (A) is in the range of 0.005 to 0.3 mol / kg. The polyurethane composition according to claim 1 or 2, wherein the content of urethane bonds in the polyurethane (A) is 0.2 mol / kg or more. The polyurethane composition according to any one of claims 1 to 3, wherein the compound (a-2) having three hydroxyl groups is polyoxyethylene polyoxypropylene triol. A sheet formed from the polyurethane composition according to any one of claims 1 to 4.