JP2010144066A - Water cut-off polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide water cut-off polyurethane foam excellent in lightness, causing no bleeding from the polyurethane foam and excellent in water cut-off property for long term. <P>SOLUTION: A water cut-off polyurethane foam having 15-40 kg/m<SP>3</SP>density is formed of a polyurethane foam raw material comprising a polyol ingredient, isocyanate, a foaming agent, a catalyst and a water repellent, wherein 80-100 pts.wt. hydroxy group-terminated prepolymer obtained by reacting polyetherpolyol with isocyanate is contained in 100 pts.wt. polyol ingredient, the water repellent is at least one selected from the group consisting of polybutadienepolyol, hydrogenated polyol of polybutadiene, polyisoprenepolyol and hydrogenated polyol of polyisoprene, and the isocyanate index is 100-150. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a water-stopping polyurethane foam that can be compressed with low stress, has no deformation at the time of compression, has excellent water-stopping performance even when used for a long period of time, and is excellent in lightness.

  Conventionally, as a water-stopping polyurethane foam composed of polyurethane foam, (1) at least one kind of polyol obtained by addition polymerization of 90% mol or more of polydiene polyol, dimer acid polyol and alkylene oxide having 3 or more carbon atoms as a polyol component of polyurethane foam And a combination of a hydroxyl group-containing organosilicone (see Patent Document 1) and (2) a foam stabilizer that uses an organosilicone compound based on a polydialkylsiloxane having a primary or secondary amino group (patent) (Ref. 2), (3) Polyolefin polyol is used as polyhydroxyl compound, and carboxy-modified organosilicone is used as a foam stabilizer (see Patent Document 3), (4) Specific polyol having 4 to 50 carbon atoms When 7 to 100 of an addition-type ester condensate composed of a monocarboxylic acid having a prime number of 12 or more or the monocarboxylic acid and a dicarboxylic acid having 8 or more carbon atoms with respect to 100 parts by weight of the compound having at least two active hydrogen groups. There is one including a weight part (see Patent Document 4).

  However, (1) to (4) have the following problems. That is, in the case of (1), when the density is low, void-like pinholes or cracks are generated in the foam, which makes it difficult to reduce the density. (2) has the problem that the water stop effect is not enough. (3) has a problem that the water-stopping property is not sufficient yet. (4) has the problem that there are many bleeds.

Japanese Patent Publication No. 2-55470 JP-B-1-38152 JP-A-7-109369 JP-A-8-333432

  The present invention has been made in view of the above points, and has a cell structure of open cells while having a very low air permeability, so that it can be easily compressed with low stress and can be compressed even at a high magnification. The polyurethane foam is less deformed when compressed, has excellent lightness, has very little bleeding from organic volatile substances (VOC) and fogging from the polyurethane foam, and is excellent in water-stopping polyurethane foam. For the purpose of provision.

The present invention is a polyol component, an isocyanate, a blowing agent, a catalyst, a water-blocking polyurethane foams of polyurethane foam density formed from polyurethane foam material 15kg ^/ m ³ ~40kg / m 3 comprising a water repellent agent, the The polyol component contains 80 to 100 parts by weight of a hydroxyl-terminated prepolymer obtained by reaction of polyether polyol and isocyanate in 100 parts by weight, and the water repellent is polybutadiene polyol, hydrogenated polyol of polybutadiene, polyisoprene polyol, poly It consists of at least one selected from the group of hydrogenated polyols of isoprene, and has an isocyanate index of 100 to 150.

  In the water-stopping polyurethane foam of the present invention, the polyol component consists of a hydroxyl group-terminated prepolymer obtained by the reaction of a polyether polyol and an isocyanate alone or a combination of polyols other than the hydroxyl-terminated prepolymer. Since 100 to 100 parts by weight of a polyol component contains 80 to 100 parts by weight of a hydroxyl group-terminated prepolymer obtained by the reaction of a polyether polyol and an isocyanate, the viscosity of the polyurethane foam raw material is increased, and the cell becomes finer during foam formation. By increasing the film (mirror) that covers the cell skeleton of the polyurethane foam, the air permeability is reduced, it becomes difficult for water to enter the cell, and the water stoppage is improved. When a polyether polyol is used as a hydroxyl group-terminated prepolymer constituting the polyol component and a polyol other than the hydroxyl group-terminated prepolymer, the hydrolysis resistance is improved because the polyol component is composed only of the polyether polyol.

  Further, the water-repellent polyurethane foam of the present invention uses at least one selected from the group of polybutadiene polyol, hydrogenated polyol of polybutadiene, polyisoprene polyol, and hydrogenated polyol of polyisoprene as the water repellent agent. The agent is taken into the resin skeleton of the foam, and the water repellent bleed does not occur, the foam is less likely to deteriorate with time and the water repellency is lowered, and good water stopping properties can be exhibited over a long period of time. Furthermore, by setting the isocyanate index to 100 to 150, the polyol component and the water repellent are completely resinated, and since the isocyanate is present in excess, secondary crosslinking reaction of the isocyanate (allophanate bond, burette bond, etc.) Occurs, the water repellency of the foam is further increased, and the water stoppage is further improved.

Furthermore, the water-blocking polyurethane foams of the present invention, since density of ^{15kg / m 3 ~40kg / m 3} , are excellent in lightweight properties as compared to conventional water-blocking polyurethane foam (density 40 kg / ^{m 3} or higher).

The water-stopping polyurethane foam in the present invention has a density of 15 kg / m ^{3 to} 40 kg / m ³ , more preferably 20 kg / m ³ formed from a polyurethane foam raw material containing a polyol component, an isocyanate, a foaming agent, a catalyst, and a water repellent. ~40kg / ^{m 3,} more ^preferably, a polyurethane foam of ^{25kg / m 3 ~35kg / m 3} (JIS K 7222).

  The polyol component contains 80 to 100 parts by weight of a hydroxyl group-terminated prepolymer obtained by a reaction between a polyether polyol and an isocyanate in 100 parts by weight of the polyol component. Since the hydroxy-terminated prepolymer is contained in an amount of 80 to 100 parts by weight, the viscosity of the polyurethane foam raw material is increased, the cells are refined during foam formation, and the number of mirrors covering the cell skeleton of the polyurethane foam is increased, thereby reducing air permeability. Water stoppage is improved. When the amount of the hydroxyl group-terminated prepolymer is less than the above range, it becomes difficult to make the polyurethane foam cells finer and reduce the air permeability, and the water stoppage is lowered.

  The polyether polyol used for the production of the hydroxyl group-terminated prepolymer in the present invention is bifunctional or higher, and trifunctional or higher is preferred to obtain a polyurethane foam with finer cells. The bifunctional or higher functional polyether polyol is not particularly limited, and examples thereof include ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, hydroquinone, water, resorcin, bisphenol A, hydrogenated bisphenol A, glycerin, trimethylolpropane, Starting from pentaerythritol, monoethanolamine, diethanolamine, triethanolamine, tripropanolamine, ethylenediamine, 1,6-hexanediamine, tolylenediamine, diphenylmethanediamine, triethylenetetraamine, sorbitol, mannitol, dulcitol, etc. Use polyether polyols obtained by adding alkylene oxides such as oxide and propylene oxide It is possible.

  In addition, the isocyanate used for the production of the hydroxyl-terminated prepolymer in the present invention is bifunctional or higher. Bifunctional or higher isocyanates are not particularly limited, and may be aromatic, alicyclic or aliphatic, and may be used alone or in combination.

  For example, as the bifunctional isocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'- Fragrances such as diphenylmethane diate, 2,2'-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3'-dimethyl-4,4'-biphenylene diisonate, 3,3'-dimethoxy-4,4'-biphenylene diisocyanate Alicyclic, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, methylcyclohexane diisocyanate, butane-1,4-diisocyanate, hexane Diisocyanate, isopropylene diisocyanate, methylene diisocyanate, can be mentioned aliphatic, such as lysine isocyanate.

  Trifunctional or higher isocyanates include tris (4-phenylisocyanate) thiophosphate, triphenylmethane triisocyanate, tolylene diisocyanate trimer, polymethylene polyphenyl isocyanate, diphenyl ether-2,4,4′-triisocyanate, Other examples include polyfunctional aromatic isocyanates, polyfunctional aliphatic isocyanates, and block type isocyanates.

  The hydroxyl-terminated prepolymer can be obtained from the polyether polyol and isocyanate by a known prepolymer production method. Specifically, a predetermined amount of the polyether polyol is charged into a tank heated to a predetermined temperature (for example, 80 ° C.), and a predetermined amount of the isocyanate or the catalyst is charged and reacted while stirring in a state filled with nitrogen. Thus, a hydroxyl group-terminated prepolymer can be obtained.

  The polyol used as the hydroxyl group-terminated prepolymer is a polyether polyol having a molecular weight of 300 to 10,000, more preferably a molecular weight of 1000 to 8000, and still more preferably a molecular weight of 2000 to 5000. The isocyanate is not particularly limited as long as the viscosity of the hydroxyl group-terminated prepolymer does not make the production difficult, but tolylene diisocyanate is effective. The viscosity of the hydroxyl group-terminated prepolymer is 2000 to 30000 mPa · s at 30 ° C., more preferably 4000 to 28000 mPa · s, and still more preferably 8000 to 25000 mPa · s.

  In the case where the amount of the hydroxyl group-terminated prepolymer contained in 100 parts by weight of the polyol component is less than 100 parts by weight, the polyol used in combination as the polyol component is not particularly limited. Polymer polyol, polyether ester polyol or polyester polyol obtained by graft polymerization of acrylonitrile or acrylonitrile may be used. In particular, polyether polyol is preferable, and it is more preferable to use together the polyether polyol used as a raw material for producing the hydroxyl-terminated prepolymer. Moreover, when using a polyester polyol as a polyol used together as the polyol component, in order to obtain a water-resistant polyurethane foam excellent in hydrolysis resistance, 3-methyl-1,5-pentanediol or 2-methyl- Bifunctional or more obtained by condensing branched diol such as 1,8-octanediol and dicarboxylic acid such as adipic acid (aliphatic), dimer acid (alicyclic), phthalic acid (aromatic) Polyester polyols obtained by ring-opening polymerization of various lactones such as polycarbonate diol, polycarbonate diol, caprolactone, and the like are preferable.

  As the isocyanate to be reacted with the polyol component, known aromatic, alicyclic and aliphatic isocyanates for polyurethane foam may be used alone or in combination. For example, aromatic isocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'- Diphenylmethane diate, 2,2′-diphenylmethane diisocyanate, xylylene diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisonate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, and the like Examples of cyclic isocyanates include cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, and methylcyclohexane diisocyanate. Cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, can be mentioned methyl cyclohexane diisocyanate.

  As the foaming agent, water is suitable. About 1.5 to 6 parts by weight is suitable for 100 parts by weight of the polyol component.

  As the catalyst, those known for polyurethane foam can be used. For example, amine catalysts such as triethylamine, triethylenediamine, diethanolamine, dimethylaminomorpholine, N-ethylmorpholine, tetramethylguanidine, stannous octoate, Examples thereof include tin catalysts such as dibutyltin dilaurate, and metal catalysts (also referred to as organometallic catalysts) such as phenylmercury propionate or lead octenoate. The general amount of the catalyst is about 0.2 to 5 parts by weight with respect to 100 parts by weight of the polyol.

  The water repellent is at least one selected from the group consisting of polybutadiene polyol, hydrogenated polyol of polybutadiene, polyisoprene polyol, and hydrogenated polyol of polyisoprene. The polyol used as the water repellent has a molecular weight of 500 to 6000, more preferably a molecular weight of 1000 to 5000, still more preferably a molecular weight of 1000 to 3500, and a hydroxyl value of 15 to 120 mgKOH / g, more preferably a hydroxyl value. It is 25-110 mgKOH / g, More preferably, it is 35-70 mgKOH / g. The number of functional groups is 1.6 or more, more preferably 2 or more. By using the polyol as a water repellent, the water repellent is incorporated into the resin skeleton, and there is little risk of deterioration of the foam over time or water repellency due to bleed of the water repellent. It becomes possible to exhibit aqueous properties. The polyol of the water repellent is separate from the polyol component, and is 3 to 30 parts by weight, more preferably 5 to 20 parts by weight, and still more preferably 10 to 15 parts by weight with respect to 100 parts by weight of the polyol component. Part addition amount is preferred. If the amount is less than 3 parts by weight, the effect of improving the water-stopping performance is reduced.

Generally, polyurethane foam used as a water-stopping material is compressed between a metal and a different material such as a thermoplastic resin or a thermosetting resin. Must adhere to each other.
In actual use, if the polyurethane foam contains a compound that can cause organic volatile substances (VOC), the metal surface or the resin surface may be adversely affected by chemical attack or bleed. In addition, when used after being compressed with a transparent material such as glass, a problem of fogging such as fogging occurs.

  In the water-stopping polyurethane foam of the present invention, by selecting a water repellent, the amount of eluate is very small at 5% or less in the Soxhlet extraction method with acetone (extraction time: 8 hours), and the above problems do not occur. At present, the amount of eluate of the water-stopping polyurethane foam that is generally used is about 15%, and that the amount of eluate of the present invention is 5% or less is substantially different from general-purpose polyurethane foam that does not contain a water repellent. The performance is equivalent to

  Isocyanate index is 100-150, More preferably, it is 105-140, More preferably, it is 110-130. By setting the isocyanate index to 100 to 150, the polyol component and the water repellent are completely resinated, and since the isocyanate is excessive, secondary crosslinking reaction of the isocyanate (allophanate bond, burette bond, etc.) occurs. The water repellency of the foam is further increased, and the water stoppage is further improved. When the isocyanate index is less than 100, the water stopping performance is lowered. The upper limit of the isocyanate index need not be particularly limited, but if it exceeds 150, the internal heat generation temperature in the polyurethane foam becomes high when foam is foamed (particularly when foamed into a soft slab foam), and scorch is generated and natural. Risk of ignition. The range of a preferable isocyanate index is 100 to 150, more preferably 105 to 140, and still more preferably 110 to 130. The isocyanate index is an index used in the field of polyurethane, and is a poly- mer with active hydrogen groups in raw materials (for example, active hydrogen groups contained in hydroxyl groups of polyols and active hydrogen groups such as water as a blowing agent). It is a numerical value [equivalent of NCO group / equivalent of active hydrogen group × 100] representing the equivalent ratio of isocyanate groups of isocyanate as a percentage.

  In addition, additives such as foam stabilizers and pigments can be appropriately blended. Any foam stabilizer may be used as long as it is used for polyurethane foams, and examples thereof include silicone foam stabilizers, fluorine-containing compound foam stabilizers, and known surfactants. As the pigment, those according to the required color are used.

  The polyurethane foam is prepared by a known foaming method in which a polyurethane foam raw material comprising the polyol component, isocyanate, foaming agent, catalyst, water repellent, and appropriate additives is stirred and mixed to react the polyol component with isocyanate to foam. Manufactured.

  In addition, the water-stopping polyurethane foam of the present invention has a 100 mmAq water pressure holding time of 9 hours or more, more preferably 24 hours or more, and exhibits extremely excellent water-stopping properties. As shown in FIG. 1, the holding time is determined by punching a 10 mm-thick water-resistant polyurethane foam 50 into a U shape and sandwiching the two acrylic resin plates 71 and 71 in a compressed state of 50%. Water was injected into the font so as to obtain a 100 mAq water pressure, and the time during which the 100 mmAq water pressure was maintained was measured as a water stop time.

Using the polyurethane raw material which consists of a mixing | blending shown in Table 1 and Table 2, the water stop polyurethane foam which consists of the polyurethane foam of an Example and a comparative example was created. Each component of Table 1 and Table 2 is as follows.
Polyol component A1: synthesized by reacting a mixture of polyether polyol (polyol component A2 described later) / isocyanate (isocyanate described later) = 2 mol / 1 mol in the presence of a metal catalyst at 80 ° C. for about 2 hours. Hydroxyl-terminated prepolymer, hydroxyl value 33 mgKOH / g, viscosity 17000 mPa · s (30 ° C.).
Polyol component A2: polyether polyol, molecular weight 3000, functional group number 3, hydroxyl value 56 mgKOH / g, product number: GP-3000, manufactured by Sanyo Chemical Industries, Ltd. Polyol component A3: polyester polyol, molecular weight 2000, functional group number 3, hydroxyl group Value: 84 mg KOH / g, product number: F-2010 (condensation polymerization of trimethylolpropane with 3-methyl-1,5-pentanediol and adipic acid), manufactured by Kuraray Co., Ltd. Water repellent C1: polybutadiene polyol, molecular weight 2100, functional group number 2, product number: LBH-P2000, manufactured by Sartomer ・ Water repellent C2: hydrogenated polybutadiene polyol, molecular weight 3,100, functional group number 2, product number: HLBH-P3000, manufactured by Sartomer ・ Water repellent C3: polybutadiene polyol , Molecular weight 12 00, functional group number 2.3, product number: R-15HT, manufactured by Idemitsu Kosan Co., Ltd. ・ Water repellent C4: isoprene polyol, molecular weight 2500, functional group number 2.1, product number: Very ip, manufactured by Idemitsu Kosan Co., Ltd. Agent C5: Hydrogenated isoprene polyol, molecular weight 2500, functional group number 2.3, product number: Epaul, Idemitsu Kosan Co., Ltd. Water repellent C6: petroleum liquid resin, product number: SAS-LH, Shin Nippon Oil Co., Ltd. Foaming agent: water Foam stabilizer: silicone type, product number: SZ-1919, manufactured by Toray Dow Corning Co., Ltd. Catalyst F1: Triethylenediamine, product number: DABCO-33LV, manufactured by Air Products Japan Co., Ltd. Catalyst C2: Octylic acid Stannous, product number: MRH-110, manufactured by Johoku Chemical Industry Co., Ltd. ・ Isocyanate: 2,4-TDI / 2,6-TD1 = 80/20 Part number: T-80, manufactured by Nippon Polyurethane Industry Co., Ltd.

Density (kg / m ³ , JIS K 7222), air permeability: (cc / cm ² / sec, JIS K 6400-7B method), number of cells (pieces / piece) 25 mm, JIS K 6400-1), compressive strain (%, JIS K 6400-4), water stoppage (time), and acetone extract amount (%) were measured.

  The measurement results are shown at the bottom of Tables 1 and 2. The water-stopping measurement was performed according to the method shown in FIG. Note that “1>” in the results of the water stoppage time in the table indicates that water leaks within one hour after water is injected from above the waterstop polyurethane foam 50 so as to have a water pressure of 100 mmAq, and between the acrylic resin plates 71 and 71. Means that the water could not be retained, that is, the water stoppage time was less than 1 hour, while “24 <” means longer than 24 hours. The measurement results were evaluated as “評 価” when the measurement time was 24 hours or more, “◯” when less than 8-24 hours, and “x” when less than 8 hours. The amount of acetone extract was measured by the Soxhlet extraction method. As measurement conditions, 1 g of polyurethane foam was extracted in 100 g of acetone for 8 hours, and the weight of the amount of the extract was measured. Less than 3% was “◎”, less than 5% was “◯”, and 5% or more was “x”.

As understood from the measurement results shown in Table 1, the water-stopping polyurethane foams of the examples have a density of 22 to 40 kg / m ³ , a water-stopping time of 100 mmAq water pressure of 9 hours or more, and light weight and water-stopping properties are good. It was something. In particular, Example 12 having an isocyanate index of 100 had a water stoppage time of 9 hours, while other Examples 1 to 11 and 13 to 20 having an isocyanate index of 110 or more had a waterstop time of 13 hours or more. In Examples 14 to 16 having an isocyanate index of 130 or more, although the water stoppage time was excellent as 24 hours or more, the number of cells tended to decrease. This is thought to be due to the fact that the viscosity of the entire polyurethane foam raw material has decreased due to an increase in the amount of isocyanate used. From this, it can be seen that a more preferable isocyanate index is 110 to 130.

  On the other hand, as shown in Table 2, Comparative Example 1 containing no water repellent was extremely inferior in water stopping time with a water stopping time of 1 hour. Moreover, the comparative example 2 which does not contain a prepolymer in a polyol component and a polyol component consists of 100% of polyether polyols had a water stop time of less than 1 hour, and there was no water stop. Further, Comparative Example 3 containing 75 parts by weight of the prepolymer in 100 parts by weight of the polyol component has a water stop time of 5 hours, which is much inferior to the water stop time of 13 hours of Example 9 containing 80 parts by weight of the prepolymer. It was. Moreover, the comparative example 4 of the isocyanate index 95 has a water stop time of less than 1 hour, Example 10 of the isocyanate index 100 has a water stop time of 9 hours, and Example 1 of the isocyanate index 120 has a water stop time of 24 hours or more. It can be seen that the water-stopping property is extremely inferior to that of the existing one. Moreover, the comparative example 5 which used petroleum-type liquid resin as a water repellent has a water stop time of 4 hours, and was inferior to the water stop from Examples 1-20.

  Regarding the measurement results of the amount of acetone extract of Example 1 and Comparative Example 5 (Soxhlet extraction method, extraction time 8 hours), Example 1 is 1.1%: “◎”, and Example 5 is 13.9. %: “×”. The amount of extract of ECS (manufactured by Inoac Corporation, ether polyurethane foam), which is a general-purpose polyurethane foam, was 0.8%: “◎”. It can be seen that the water-stopping polyurethane foam of the present invention has a very small amount of eluate.

It is a figure which shows the water stop measuring method.

Explanation of symbols

50 Water-resistant polyurethane foam 71 Acrylic resin board

Claims (2)

The polyol component, isocyanate, blowing agent, catalyst, a water-blocking polyurethane foams of polyurethane foam density formed from polyurethane foam material 15kg ^{/ m 3} ~40kg ^/ m 3 comprising a water repellent,
The polyol component contains 80 to 100 parts by weight of a hydroxyl group-terminated prepolymer obtained by reaction of polyether polyol and isocyanate in 100 parts by weight,
The water repellent comprises at least one selected from the group consisting of polybutadiene polyol, hydrogenated polyol of polybutadiene, polyisoprene polyol, and hydrogenated polyol of polyisoprene,
A water-stopping polyurethane foam characterized by having an isocyanate index of 100 to 150.   The water-repellent polyurethane foam according to claim 1, wherein the water repellent is 3 to 30 parts by weight with respect to 100 parts by weight of the polyol component.

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