Polyurethane foam and its manufacturing method

Abstract

To provide a polyurethane foam which is free from fear of silicone contamination.MEANS FOR SOLVING THE PROBLEM: In a polyurethane foam obtained from a polyurethane reaction composition and a gas for foaming, the polyurethane reaction composition comprises a polyol component and an isocyanate component. The polyol component is a 2 or 3 component systems comprising polyol A which comprises a block copolymer of ethylene oxide and propylene oxide and at least one of polyol B which comprises a polyether having a terminal primary OH and polyol C which comprises an ester polyol. A density of the polyurethane foam according to JIS K6401 is 200 to 330 kg / m3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a polyurethane foam free from silicone contamination and a method for producing the same. [Background technology]

[0002] Polyurethane foams formed from a polyurethane reaction composition and a foam-forming gas have low hardness and low breathability, and are therefore suitable for use as sealing materials, packing materials, cushioning materials, etc. Polyurethane foams formed from a polyurethane reaction composition and a foam-forming gas are produced by the mechanical froth method.

[0003] The mechanical froth method is a method of forming polyurethane foam by supplying a mixed raw material, in which a foam-forming gas is compressed and mixed into a polyurethane reaction composition, to an oaks mixer or a nozzle with a narrowed tip, and then discharging it from the oaks mixer or nozzle.

[0004] In the conventional mechanical froth method, a foam stabilizer made of a silicone compound is contained in the polyurethane reaction composition in order to form bubbles well (Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-179705 Summary of the Invention [Problem to be solved by the invention]

[0006] However, conventional polyurethane foams formed from a polyurethane reaction composition and a foam-forming gas use a foam stabilizer made of a silicone compound, and therefore, when used in proximity to electronic components, for example, as sealing materials, packing materials, and cushioning materials for electronic storage devices such as hard disk drives (HDDs), smartphones, and other electronic devices and components, there is a risk of silicone contamination that adversely affects their functionality, making them undesirable.

[0007] The present invention has been made in consideration of the above-mentioned points, and an object of the present invention is to provide a polyurethane foam formed from a polyurethane reaction composition and a foam-forming gas, which is free from the risk of silicone contamination of electronic devices, electronic components, etc. [Means for solving the problem]

[0008] The invention of claim 1 relates to a polyurethane foam obtained from a polyurethane reaction composition and a foaming gas, wherein the polyurethane reaction composition comprises a polyol component, a catalyst, and an isocyanate component, and the polyol component comprises a two-component or three-component system including polyol A consisting of a block copolymer of ethylene oxide and propylene oxide, and at least one of polyol B consisting of an ether polyol with a terminal primary OH group or polyol C consisting of an ester polyol, and in the case of a two-component system consisting of polyol A and polyol B, In the case of a two-component system of the polyol A and the polyol C, the polyol A is 13 to 75 parts by weight and the polyol C is 25 to 87 parts by weight in 100 parts by weight of the polyol component; in the case of a three-component system of the polyol A, the polyol B and the polyol C, the polyol A is 13 to 80 parts by weight, the polyol B is 10 to 65 parts by weight and the polyol C is 10 to 70 parts by weight in 100 parts by weight of the polyol component; and the density according to JIS K6401 is 200 to 330 kg / m 3 It is characterized in that:

[0009] The invention of claim 2 is a polyurethane foam described in claim 1, characterized in that the polyol C is at least one of polyol C1 consisting of an ester polyol having two functional groups and polyol C2 consisting of an ester polyol having three functional groups.

[0010] The invention of claim 3 is a method for producing polyurethane foam by a mechanical froth method in which a mixed raw material obtained by mixing a polyurethane reaction composition with a foaming gas is discharged into a molding die, the polyurethane reaction composition comprising a polyol component, a catalyst, and an isocyanate component, the polyol component comprising polyol A comprising a block copolymer of ethylene oxide and propylene oxide, and a two-component or three-component system including at least one of polyol B comprising an ether polyol having a terminal primary OH group or polyol C comprising an ester polyol, the polyol A and the polyol B comprising a block copolymer of ethylene oxide and propylene oxide, In the case of a two-component system of the above, the polyol A is 35 to 75 parts by weight and the polyol B is 25 to 65 parts by weight per 100 parts by weight of the polyol component; in the case of a two-component system of the above polyol A and the above polyol C, the polyol A is 13 to 75 parts by weight and the polyol C is 25 to 87 parts by weight per 100 parts by weight of the polyol component; and in the case of a three-component system of the above polyol A, the polyol B and the polyol C, the polyol A is 13 to 80 parts by weight, the polyol B is 10 to 65 parts by weight and the polyol C is 10 to 70 parts by weight per 100 parts by weight of the polyol component; and the polyurethane foam has a density according to JIS K6401 of 200 to 330 kg / m 3 It is characterized in that:

[0011] The invention of claim 4 is characterized in that, in claim 3, the ester polyol C comprises at least one of an ester polyol C1 having two functional groups and an ester polyol C2 having three functional groups. [Effects of the Invention]

[0012] According to the present invention, the polyol component is a two-component or three-component system containing polyol A, which is a block copolymer of ethylene oxide and propylene oxide, and at least one of polyol B, which is an ether polyol having a terminal primary OH group, and polyol C, which is an ester polyol. In the two-component system of polyol A and polyol B, the polyol A is 35 to 75 parts by weight and the polyol B is 25 to 65 parts by weight per 100 parts by weight of the polyol component. In the two-component system of polyol A and polyol C, the polyol A is 13 to 75 parts by weight and the polyol C is 25 to 87 parts by weight per 100 parts by weight of the polyol component. In the three-component system of polyol A, polyol B, and polyol C, the polyol A is 13 to 80 parts by weight, the polyol B is 10 to 65 parts by weight, and the polyol C is 10 to 70 parts by weight per 100 parts by weight of the polyol component. Therefore, a good polyurethane foam can be obtained without the use of a foam stabilizer made of a silicone compound, and the risk of silicone contamination can be eliminated.

[0013] Furthermore, when the polyol component is a two-component system of polyol A and polyol B, all of the polyols (A, B) are polyester polyols, and therefore excellent hydrolysis resistance can be achieved. Furthermore, when the polyol component is a two-component system of polyol A and polyol C, the addition of ester polyol provides the effect of improving strength and elongation. Furthermore, when the polyol component is a three-component system of polyol A, polyol B, and polyol C, the effect of improving strength and elongation as well as flexibility can be achieved. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a table showing the formulations and evaluation results for examples and comparative examples in which the polyol component is a two-component system. [Figure 2] 1 is a table showing the formulations and evaluation results for examples and comparative examples in which the polyol component is a three-component system. DETAILED DESCRIPTION OF THE INVENTION

[0015] An embodiment of the polyurethane foam of the present invention will be described below: The polyurethane foam of the present invention can be obtained from a polyurethane reaction composition and a foam-forming gas by a mechanical froth method. The mechanical froth method is a method of forming polyurethane foam by feeding a mixed raw material, in which a foam-forming gas is compressed and mixed into a polyurethane reaction composition, into an O-X mixer or a nozzle with a narrowed tip, and discharging it from the O-X mixer or nozzle. In the mechanical froth method, the foam-forming gas, which had been compressed until then, expands when the mixed raw material is discharged to form bubbles, and in this state, the polyol component and the isocyanate component react and harden to form polyurethane foam. Therefore, this polyurethane foam uses a foam-forming gas as a foaming function agent (foaming agent) for the polyurethane reaction composition, and the foam-forming gas is contained within the cells of the polyurethane foam.

[0016] The polyurethane reaction composition contains a polyol component, a catalyst, and an isocyanate component. In the present invention, the polyurethane reaction composition does not contain a silicone compound used as a foam stabilizer or the like. The polyol component is a two-component or three-component system containing polyol A, which is a block copolymer of ethylene oxide and propylene oxide, as the essential polyol, and at least one of polyol B, which is an ether polyol with a terminal primary OH, or polyol C, which is an ester polyol.

[0017] Polyol A, which is a block copolymer of ethylene oxide and propylene oxide, is a polyether polyol having 2 to 3 functional groups and a number-average molecular weight of 1500 to 5000, preferably 1800 to 4000. The content of structural units derived from ethylene oxide (EO content) in polyol A is not particularly limited, but because handling is easier when the block copolymer is in a liquid state, the EO content is preferably 50% by weight or less, more preferably 5 to 50% by weight, and more preferably 10 to 45% by weight.

[0018] Polyol B, which is an ether polyol having a terminal primary OH group, is for example, It is a polyether polyol obtained by adding ethylene oxide to a polyhydric alcohol using an alkali hydroxide as a catalyst. The terminal primary OH ether polyol preferably has 2 to 4 functional groups and a number average molecular weight of 400 to 8000, more preferably 1000 to 5000. Polyol B, which is made from a terminal primary OH ether polyol, has a fast resinification reaction and good moldability for polyurethane foam. In the present invention, since terminal secondary OH ether polyols have poor moldability, they are preferably used in an amount of 0 to 10 parts by weight, and more preferably not used at all (0 part by weight), per 100 parts by weight of the polyol component. The terminal secondary OH ether polyol is a polyether polyol obtained by adding propylene oxide to a low-molecular-weight polyhydric alcohol using an alkali hydroxide as a catalyst.

[0019] The polyol C made from an ester polyol is preferably composed of at least one of polyol C1 made from an ester polyol having a functionality of 2 and polyol C2 made from an ester polyol having a functionality of 3. The polyol C1 having a functionality of 2 and the polyol C3 having a functionality of 3 preferably have a number average molecular weight of 300 to 3000, more preferably 400 to 2500. If a large amount of polyol C made from an ester polyol is contained in the polyol component, the flexibility of the polyurethane foam is impaired. Therefore, when a large amount of polyol C is contained, it is preferable to use polyol B made from an ether polyol having a terminal primary OH group in combination with polyol C.

[0020] When the polyol component is a two-component system of polyol A and polyol B, the amount of each polyol is 35 to 75 parts by weight of polyol A and 25 to 65 parts by weight of polyol B in 100 parts by weight of the polyol component.

[0021] When the polyol component is a two-component system of polyol A and polyol C, the amount of each polyol is 13 to 75 parts by weight of polyol A and 25 to 87 parts by weight of polyol C per 100 parts by weight of the polyol component.

[0022] Furthermore, when the polyol component is a three-component system of polyol A, polyol B, and polyol C, the amount of each polyol is 13 to 80 parts by weight of polyol A, 10 to 65 parts by weight of polyol B, and 10 to 70 parts by weight of polyol C, per 100 parts by weight of the polyol component.

[0023] When the polyol component is a two-component or three-component system, by adjusting the amounts of polyol A, polyol B, and polyol C within the above-mentioned ranges, a good polyurethane foam can be obtained without containing a foam stabilizer made of a silicone compound. In addition to this effect, when the polyol component is a two-component system of polyol A and polyol B, it has superior hydrolysis resistance compared to other two-component and three-component systems. Furthermore, when the polyol component is a two-component system of polyol A and polyol C, the strength and elongation are superior to other two-component and three-component systems. Furthermore, when the polyol component is a three-component system of polyol A, polyol B, and polyol C, the balance of strength, elongation, and flexibility is superior compared to other two-component systems.

[0024] The catalyst may be an amine catalyst or an organometallic catalyst for polyurethane foam, either alone or in combination. Examples of the amine catalyst include monoamine compounds, diamine compounds, triamine compounds, polyamine compounds, cyclic amine compounds, alcohol amine compounds, and ether amine compounds. These may be used alone or in combination. Examples of the organometallic catalyst include organotin compounds, organoiron compounds, organobismuth compounds, organolead compounds, and organozinc compounds. These may be used alone or in combination. The amount of catalyst is determined as appropriate, but is typically 0.1 to 8 parts by weight per 100 parts by weight of the polyol component.

[0025] Optional additives may also be added to the polyurethane reaction composition, such as chain extenders, crosslinkers, fillers, dyes, pigments, antioxidants, and flame retardants. Examples of the chain extender include polyethylene glycol (PEG), dipropylene glycol (DPG), etc. When a chain extender is added, the amount of the chain extender is preferably 0.5 to 10 parts by weight per 100 parts by weight of the polyol component. Examples of crosslinking agents include polyhydric alcohols such as glycerin, butanetetraol, and polyoxypropylene glycol, diethanolamine, and polyamine. When a crosslinking agent is added, the amount of the crosslinking agent is preferably 0.5 to 10 parts by weight per 100 parts by weight of the polyol component. Examples of fillers include alumina trihydrate, silica, talc, calcium carbonate, clay, etc. When a filler is added, the amount of the filler is preferably 5 to 50 parts by weight per 100 parts by weight of the polyol component.

[0026] The isocyanate component may be any of aromatic, alicyclic, and aliphatic isocyanates, and may also be a bifunctional isocyanate having two isocyanate groups in one molecule, or a trifunctional or higher isocyanate having three or more isocyanate groups in one molecule, and these may be used alone or in combination.

[0027] For example, bifunctional isocyanates include 2,4-toluene diisocyanate (TDI), 2,6-toluene diisocyanate (TDI), m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), 2,4'-diphenylmethane diisocyanate (MDI), 2,2'-diphenylmethane diisocyanate (MDI), xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisocyanate, 3 Examples of the isocyanate include aromatic isocyanates such as 1,3'-dimethoxy-4,4'-biphenylene diisocyanate, alicyclic isocyanates such as cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, and methylcyclohexane diisocyanate, and aliphatic isocyanates such as butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, and lysine isocyanate.

[0028] Furthermore, examples of difunctional or higher isocyanates include polymethylene polyphenylisocyanate (polymeric MDI). Examples of trifunctional or higher isocyanates include 1-methylbenzene-2,4,6-triisocyanate, 1,3,5-trimethylbenzene-2,4,6-triisocyanate, biphenyl-2,4,4'-triisocyanate, diphenylmethane-2,4,4'-triisocyanate, methyldiphenylmethane-4,6,4'-triisocyanate, 4,4'-dimethyldiphenylmethane-2,2',5,5'tetraisocyanate, and triphenylmethane-4,4',4"-triisocyanate. The isocyanate is not limited to one type, and may be one or more types. For example, one type of aliphatic isocyanate and two types of aromatic isocyanate may be used in combination. The isocyanate index is preferably 90 to 110. The isocyanate index is the value obtained by multiplying the number of moles of isocyanate groups per mole of active hydrogen groups contained in the foaming raw material (polyurethane reaction composition) by 100, and is calculated by [(isocyanate equivalent in the foaming raw material / active hydrogen equivalent in the foaming raw material) × 100].

[0029] The foam-forming gas is preferably a gas that does not adversely affect the reaction between the polyol and the isocyanate, such as dry air or nitrogen. The foam-forming gas is preferably mixed in an amount of 31 to 91% by volume in the polyurethane reaction composition. The foam-forming gas mixing ratio refers to the volume % of the foam-forming gas relative to 100 parts by volume of the polyurethane reaction composition excluding the foam-forming gas.

[0030] The polyurethane foam of the present invention is produced by the mechanical froth method, in which a mixed raw material obtained by compressing and mixing a foam-forming gas into a polyurethane reaction composition is fed into an O-X mixer or a nozzle with a tapered tip and discharged from the O-X mixer or nozzle. The mixed raw material may be discharged continuously onto a release paper or by a molding method into a mold.

[0031] The polyurethane foam of the present invention has a density of 200 to 330 kg / m according to JIS K6401. 3 If the density of polyurethane foam is too low or too high, when it is used as a sealant and compressed between two objects, it will not adhere well to both objects, resulting in poor sealing performance. [Example]

[0032] Using the following raw materials, a polyurethane reaction composition having the formulation shown in Figures 1 and 2 was mixed with 85% by volume of foam-forming gas (air), and the mixture was mixed and stirred in a mechanical froth foaming machine. The mixture was continuously discharged onto release paper moving at 2 m / min and heated to 120 to 200°C to produce a 5 mm thick sheet-like polyurethane foam. Polyol A (A1): Polyether polyol composed of a block copolymer of ethylene oxide and propylene oxide, ethylene oxide content 40% by weight, number average molecular weight 2900, number of functional groups 2, product name: L-64, manufactured by ADEKA Corporation Polyol A (A2): Polyether polyol composed of a block copolymer of ethylene oxide and propylene oxide, ethylene oxide content 25% by weight, number average molecular weight 2500, number of functional groups 2, product name: L-62, manufactured by ADEKA Corporation Polyol A (A3): Polyether polyol composed of a block copolymer of ethylene oxide and propylene oxide, ethylene oxide content 14% by weight, number average molecular weight 2000, number of functional groups 2, product name: L-61, manufactured by ADEKA Corporation Polyol B (B1): Terminal primary OH ether polyol, polypropylene glycol, number average molecular weight 3000, functional group number 3, trade name; Prime Pole FF3320, manufactured by Sanyo Chemical Industries, Ltd. Polyol C (C1): Ester polyol having 2 functional groups, polycaprolactone diol, number average molecular weight 550, functionality 2, trade name: Placcel 205, manufactured by Daicel Corporation Polyol C (C2): Ester polyol having 3 functional groups, polycaprolactone triol, number average molecular weight 550, functionality 3, trade name: Placcel 305, manufactured by Daicel Corporation Polyol D: Terminal secondary OH ether polyol, number average molecular weight 3000, functionality 3, manufactured by Sanyo Chemical Industries, Ltd., trade name: Sannicstriol GP-3000 Chain extender: Dipropylene glycol; Product name: Dipropylene glycol, manufactured by AGC Corporation Catalyst: Tin catalyst, product name: MRH-110, manufactured by Johoku Chemical Industry Co., Ltd. Filler: Aluminum hydroxide, product name: CW-325LV, manufactured by Sumitomo Chemical Co., Ltd. Isocyanate: 2,4-TDI / 2,6-TDI = 80 / 20, product name: Coronate T-80, manufactured by Toso Corporation The amount of isocyanate in each of the comparative examples and examples was adjusted so that the isocyanate index was 103.

[0033] For each example and comparative example, the tensile strength (MPa), elongation (%), foamability (g), froth state, and molding density (kg / m 3 ) and 5mm thickness, moldability, cellulability, and amount of silicone detected were measured and evaluated, and an overall evaluation was made based on these results.

[0034] The tensile strength (MPa) was measured in accordance with JIS K 6251. The elongation (%) was measured based on JIS K 6251. The foamability (g) was measured by mixing the polyurethane reaction composition, stirring it for 2 minutes at room temperature and atmospheric pressure using a hand mixer, filling it into a 220 ml plastic container, and measuring its weight. The lighter the weight measured, the better the foamability (foaming). The froth state was judged by visual inspection based on the number of voids in the foamed material, with a rating of "◎" if there were almost no voids, "〇" if there were only a few, "△" if there were a fair number of voids, and "×" if there were a large number of voids or the foam had broken down and coalesced. Molding density (kg / m 3) was measured based on JIS K6401. The moldability at a thickness of 5 mm was judged based on the surface condition of the molded product, with a rating of "◎" if there were no crater-like depressions, "〇" if there were only a few depressions, and "×" if there were many depressions. The cellularity was judged by visually observing the cells in the cross section of the molded product, and was given a rating of "A" if the cells were fine and uniform, "O" if the cells were uniform, and "X" if the cells were coarse and non-uniform. The amount of silicone detected was determined by subjecting the sample to a thermal desorption apparatus (90°C x 30 minutes) and measuring the generated gas with GC-MS. "ND" indicates that no silicone was detected. The overall evaluation was "Good" if the amount of silicone detected was "ND" and all other evaluations were "Good" or higher. If silicone was detected or even one of the evaluations was "Good" or "Poor", the overall evaluation was "Poor".

[0035] <Example of two-component polyol (Polyol A + Polyol B)> Comparison Example 1 Comparative Example 1 is an example in which the amounts of polyol A (A1) and polyol B (B1) were 80 parts by weight and 20 parts by weight, respectively, per 100 parts by weight of the polyol component, respectively, and the amounts of polyol A and polyol B were outside the range of the present invention. The results of Comparative Example 1 were that the tensile strength, elongation, and molding density could not be measured. The foamability was 80.6 g, the froth state was "Good", the moldability at a thickness of 5 mm was "Poor", the cellularity was "Poor", the amount of silicone detected was "ND", and the overall evaluation was "Good".

[0036] Example 1 Example 1 is an example in which the polyol A (A1) was 75 parts by weight and the polyol B (B1) was 25 parts by weight based on 100 parts by weight of the polyol component. The results of Example 1 were: tensile strength 0.46 MPa, elongation 152%, foamability 76.3 g, froth condition "◎", molding density 285 kg / m 3 The moldability at a thickness of 5 mm was "○", the cellulability was "○", the amount of silicone detected was "ND", and the overall evaluation was "○".

[0037] Example 2 Example 2 is an example in which the polyol A (A2) was 75 parts by weight and the polyol B (B1) was 25 parts by weight based on 100 parts by weight of the polyol component. The results of Example 2 were: tensile strength 0.49 MPa, elongation 146%, foamability 81.8 g, froth condition "◎", molding density 282 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0038] Example 3 Example 3 is an example in which the polyol A (A3) was 75 parts by weight and the polyol B (B1) was 25 parts by weight based on 100 parts by weight of the polyol component. The results of Example 3 were: tensile strength 0.45 MPa, elongation 149%, foamability 82.4 g, froth condition "◎", molding density 292 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0039] Example 4 Example 4 is an example in which 50 parts by weight of polyol A (A1) and 50 parts by weight of polyol B (B1) were used in 100 parts by weight of the polyol component. The results of Example 4 were: tensile strength 0.50 MPa, elongation 156%, foamability 78.1 g, froth condition "◎", molding density 288 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0040] Example 5 Example 5 is an example in which 50 parts by weight of polyol A (A1) and 50 parts by weight of polyol B (B2) were used in 100 parts by weight of the polyol component. The results of Example 5 were: tensile strength 0.48 MPa, elongation 148%, foamability 77.6 g, froth condition "◎", molding density 290 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0041] Example 6 Example 6 is an example in which the polyol A (A1) was 35 parts by weight and the polyol B (B1) was 65 parts by weight based on 100 parts by weight of the polyol component. The results of Example 6 were: tensile strength 0.57 MPa, elongation 150%, foamability 82.3 g, froth condition "◎", molding density 266 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0042] Comparison Example 2 Comparative Example 2 is an example in which the amounts of polyol A (A1) and polyol B (B1) were 25 parts by weight and 75 parts by weight, respectively, per 100 parts by weight of the polyol component, respectively, and the amounts of polyol A and polyol B were outside the range of the present invention. For Comparative Example 2, it was not possible to prepare a sample, and therefore it was not possible to measure the tensile strength, elongation, molding density, moldability, and cellularity. The foaming was 98.8 g, the froth state was "x", the amount of silicone detected was "ND", and the overall evaluation was "x".

[0043] <Example of two-component polyol (Polyol A + Polyol C)> Comparative Example 3 Comparative Example 3 is an example in which the amounts of polyol A (A1) and polyol C (C2) were 80 parts by weight and 20 parts by weight, respectively, per 100 parts by weight of the polyol component, respectively, and the amounts of polyol A and polyol C were outside the range of the present invention. In Comparative Example 3, the tensile strength and elongation could not be measured, the foaming ability was 75.1 g, the froth state was "Excellent", and the molding density was 294 kg / m 3 The moldability at a thickness of 5 mm was "○", the cellulability was "×", the amount of silicone detected was "ND", and the overall evaluation was "×".

[0044] Example 7 Example 7 is an example in which the polyol A (A1) was 75 parts by weight and the polyol C (C2) was 25 parts by weight based on 100 parts by weight of the polyol component. The results of Example 7 were: tensile strength 1.48 MPa, elongation 179%, foamability 76.2 g, froth condition "◎", molding density 266 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0045] Example 8 Example 8 is an example in which 50 parts by weight of polyol A (A1) and 50 parts by weight of polyol C (C1) were used in 100 parts by weight of the polyol component. The results of Example 8 were: tensile strength 2.14 MPa, elongation 216%, foamability 77.5 g, froth condition "◎", molding density 277 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0046] Example 9 Example 9 is an example in which 25 parts by weight of polyol A (A1) and 75 parts by weight of polyol C (C2) were used in 100 parts by weight of the polyol component. The results of Example 9 were: tensile strength 8.26 MPa, elongation 52%, foamability 73.5 g, froth condition "◎", molding density 270 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0047] Example 10 Example 10 is an example in which 25 parts by weight of polyol A (A2) and 75 parts by weight of polyol C (C2) were used in 100 parts by weight of the polyol component. The results of Example 10 were: tensile strength 8.44 MPa, elongation 57%, foamability 79.6 g, froth condition "◎", molding density 299 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0048] Example 11 Example 11 is an example in which 25 parts by weight of polyol A (A3) and 75 parts by weight of polyol C (C2) were used in 100 parts by weight of the polyol component. The results of Example 11 were: tensile strength 8.59 MPa, elongation 54%, foamability 82.7 g, froth condition "◎", molding density 325 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0049] Example 12 Example 12 is an example in which the polyol A (A1) was 13 parts by weight and the polyol C (C2) was 87 parts by weight based on 100 parts by weight of the polyol component. The results of Example 12 were: tensile strength 6.44 MPa, elongation 50%, foamability 74.8 g, froth condition "◎", molding density 289 kg / m 3 The moldability at a thickness of 5 mm was "○", the cellulability was "○", the amount of silicone detected was "ND", and the overall evaluation was "○".

[0050] Comparative Example 4 Comparative Example 4 is an example in which the amounts of polyol A (A1) and polyol C (C2) were 10 parts by weight and 90 parts by weight, respectively, per 100 parts by weight of the polyol component, respectively, and the amounts of polyol A and polyol C were outside the range of the present invention. In Comparative Example 4, it was not possible to prepare a sample, and therefore it was not possible to measure the tensile strength, elongation, molding density, moldability, and cellulosity. The foamability was 108.8 g, the froth state was "x", the amount of silicone detected was "ND", and the overall evaluation was "x".

[0051] <Example of a three-component polyol (Polyol A + Polyol B + Polyol C)> Comparative Example 5 Comparative Example 5 is an example in which, per 100 parts by weight of the polyol component, the amounts of polyol A (A1) were 90 parts by weight, polyol B (B1) were 5 parts by weight, and polyol C (C2) were 5 parts by weight, and the amounts of polyol A, polyol B, and polyol C were outside the range of the present invention. In Comparative Example 5, it was not possible to prepare a sample, and therefore it was not possible to measure the tensile strength, elongation, molding density, moldability, and cellulosity. The foamability was 105.2 g, the froth state was "x", the amount of silicone detected was "ND", and the overall evaluation was "x".

[0052] Example 13 Example 13 is an example in which 80 parts by weight of polyol A (A1), 10 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 13 were: tensile strength 0.68 MPa, elongation 101%, foamability 79.2 g, froth condition "good", molding density 288 kg / m 3 The moldability at a thickness of 5 mm was "Good", the cellulability was "Good", the amount of silicone detected was "ND", and the overall evaluation was "Good".

[0053] Example 14 Example 14 is an example in which 65 parts by weight of polyol A (A1), 25 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 14 were: tensile strength 1.57 MPa, elongation 146%, foamability 75.8 g, froth condition "◎", molding density 269 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0054] Example 15 Example 15 is an example in which 65 parts by weight of polyol A (A2), 25 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 15 were: tensile strength 1.76 MPa, elongation 145%, foamability 77.7 g, froth condition "◎", molding density 289 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0055] Example 16 Example 16 is an example in which 65 parts by weight of polyol A (A3), 25 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 16 were: tensile strength 1.76 MPa, elongation 158%, foamability 78.8 g, froth condition "◎", molding density 301 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0056] Example 17 Example 17 is an example in which 35 parts by weight of polyol A (A1), 55 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 17 were: tensile strength 0.57 MPa, elongation 150%, foamability 82.3 g, froth condition "◎", molding density 266 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0057] Example 18 Example 18 is an example in which 25 parts by weight of polyol A (A1), 65 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 18 were: tensile strength 0.90 MPa, elongation 140%, foamability 74.4 g, froth condition "◎", molding density 271 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0058] Example 19 Example 19 is an example in which 25 parts by weight of polyol A (A2), 65 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 19 were: tensile strength 1.04 MPa, elongation 150%, foamability 76.6 g, froth condition "◎", molding density 285 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0059] Example 20 Example 20 is an example in which 25 parts by weight of polyol A (A3), 65 parts by weight of polyol B (B1), and 10 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 20 were: tensile strength 1.29 MPa, elongation 165%, foamability 81.2 g, froth condition "◎", molding density 293 kg / m 3The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0060] Example 21 Example 21 is an example in which 25 parts by weight of polyol A (A1), 10 parts by weight of polyol B (B1), and 65 parts by weight of polyol C (C2) were used per 100 parts by weight of the polyol component. The results of Example 21 were: tensile strength 8.87 MPa, elongation 61%, foamability 70.7 g, froth condition "◎", molding density 267 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0061] Example 22 Example 22 is an example in which 100 parts by weight of the polyol component contained 13 parts by weight of polyol A (A1), 17 parts by weight of polyol B (B1), and 70 parts by weight of polyol C (C2). The results of Example 22 were: tensile strength 8.22 MPa, elongation 57%, foamability 75.9 g, froth condition "◎", molding density 306 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0062] Example 23 Example 23 is an example in which, per 100 parts by weight of the polyol component, polyol A (A1) was 13 parts by weight, polyol B (B1) was 17 parts by weight, polyol C (C1) was 30 parts by weight, and polyol C (C2) was 40 parts by weight. The results of Example 23 were: tensile strength 9.67 MPa, elongation 120%, foamability 77.5 g, froth condition "◎", molding density 259 kg / m 3 The moldability at a thickness of 5 mm was "◎", the cell property was "◎", the amount of silicone detected was "ND", and the overall evaluation was "◯".

[0063] Comparative Example 6 Comparative Example 6 is an example in which, per 100 parts by weight of the polyol component, polyol A (A1) was 10 parts by weight, polyol B (B1) was 60 parts by weight, and polyol C (C2) was 30 parts by weight, and the amounts of polyol A, polyol B, and polyol C were outside the range of the present invention. In Comparative Example 6, the tensile strength and elongation could not be measured, the foaming ability was 82.5 g, the froth state was "△", and the molding density was 303 kg / m 3 The moldability at a thickness of 5 mm was "Good", the cellulability was "Poor", the amount of silicone detected was "ND", and the overall evaluation was "Poor".

[0064] Comparative Example 7 Comparative Example 7 is an example in which, per 100 parts by weight of the polyol component, polyol A (A1) was 10 parts by weight, polyol B (B1) was 20 parts by weight, polyol C (C1) was 30 parts by weight, and polyol C (C2) was 40 parts by weight, and the amounts of polyol A, polyol B, and polyol C were outside the range of the present invention. In Comparative Example 7, the tensile strength and elongation could not be measured, the foaming ability was 78.3 g, the froth state was "△", and the molding density was 275 kg / m 3 The moldability at a thickness of 5 mm was "Good", the cellulability was "Poor", the amount of silicone detected was "ND", and the overall evaluation was "Poor".

[0065] Comparative Example 8 Comparative Example 8 is an example in which, per 100 parts by weight of the polyol component, 25 parts by weight of polyol A (A1), 50 parts by weight of polyol D, and 25 parts by weight of polyol C (C2) were used, and the amounts of polyol A, polyol B, and polyol C were outside the range of the present invention. In Comparative Example 8, the tensile strength, elongation, and molding density could not be measured, and the foamability was 87.4 g, the froth state was "△", the moldability at a thickness of 5 mm was "×", the cellularity was "×", the amount of silicone detected was "ND", and the overall evaluation was "×".

[0066] Comparative Example 9 Comparative Example 9 is an example in which, per 100 parts by weight of the polyol component, 25 parts by weight of polyol A (A1), 25 parts by weight of polyol D, and 25 parts by weight of polyol C (C2) were used, and the amounts of polyol A, polyol B, and polyol C were outside the range of the present invention. In Comparative Example 9, the tensile strength, elongation, and molding density could not be measured, and the foamability was 83.2 g, the froth state was "△", the moldability at a thickness of 5 mm was "×", the cellulosity was "×", the amount of silicone detected was "ND", and the overall evaluation was "×".

[0067] As described above, the present invention can provide a good polyurethane foam without using a foam stabilizer made of a silicone compound. Therefore, the polyurethane foam of the present invention can eliminate the risk of silicone contamination of electronic devices and electronic components, and is suitable for applications where silicone contamination is a problem.

Claims

1. A polyurethane foam obtained from a polyurethane reaction composition and a foaming gas, The polyurethane reaction composition includes a polyol component and an isocyanate component, The polyol component is The composition is a two-component system including polyol A made of a block copolymer of ethylene oxide and propylene oxide, and polyol C made of an ester polyol, In 100 parts by weight of the polyol component, the polyol A is 13 to 75 parts by weight and the polyol C is 25 to 87 parts by weight, Density according to JIS K6401 is 200 to 330 kg / m ３ A polyurethane foam characterized by:

2. 2. The polyurethane foam according to claim 1, wherein the polyol C comprises at least one of polyol C1 consisting of an ester polyol having two functional groups and polyol C2 consisting of an ester polyol having three functional groups.

3. A method for producing a polyurethane foam by a mechanical froth method in which a polyurethane reaction composition and a foam-forming gas are mixed to obtain a mixed raw material, and the mixed raw material is discharged into a mold, comprising: The polyurethane reaction composition includes a polyol component and an isocyanate component, The polyol component is The composition is a two-component system including polyol A made of a block copolymer of ethylene oxide and propylene oxide, and polyol C made of an ester polyol, In 100 parts by weight of the polyol component, the polyol A is 13 to 75 parts by weight and the polyol C is 25 to 87 parts by weight, The polyurethane foam has a density of 200 to 330 kg / m according to JIS K6401. ３ 1. A method for producing a polyurethane foam, comprising:

4. 4. The method for producing a polyurethane foam according to claim 3, wherein the polyol C comprises at least one of an ester polyol C1 having two functional groups and an ester polyol C2 having three functional groups.

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