JPH08239444A - Waterproof resin foam - Google Patents

Abstract

(57) [Abstract] [Purpose] A waterproof resin foam such as a waterproof polyurethane foam, in which the original properties of the foam are not impaired and the excellent waterproof property is stably maintained over a long period of time. provide. [Structure] 30 parts by weight (hereinafter referred to as “parts”) of TDI-based polyisocyanate, 80 parts of polyether polyol and 20 parts of liquid chloroprene-based hydrophobic polyol, 2 parts of water as a foaming agent, amine-based and tin-based. A total of 0.43 parts of the catalyst, 1 part of the silicone type foam stabilizer, and 12 parts of the flame retardant, and 5 parts of octadecylamine were mixed at a relatively low temperature of 10 ° C. After being prepared, it is then foamed and cured to obtain a waterproof polyurethane foam having a water absorption of 3.6%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof resin foam which is excellent in waterproofness and whose performance is stably maintained over a long period of time. The waterproof resin foam of the present invention can be used as a sealing material, a caulking material, or a hygienic cushioning material for a mattress having no hygroscopicity.

[0002]

2. Description of the Related Art A resin foam such as a polyurethane foam used as a sealing material, a caulking material or the like has been conventionally provided with a waterproof property.
(1) Reduce the cell diameter of the foam, increase the surface area even at the same density to reduce air permeability, and as a result, improve waterproofness, (2) waxes, coal tar, asphalt, decomposed naphtha Petroleum resin obtained by polymerizing a fraction having 4 to 9 carbon atoms, polybutene, dialkyl phthalate and the like are added to the foam to improve the waterproof property by making a contact angle with water of 75 degrees or more (Japanese Patent Laid-Open Publication No. Sho. 55-71777),

(3) By using a hydrophobic polyol and using a specific organosilicon compound as a foam stabilizer, the foam is made water repellent and waterproof is improved (JP-A-3-68677, etc.). ), (4) Commercially available water repellent (manufactured by Hodogaya Chemical Co., Ltd., trade name “Octex E”)
M "), silicone wax, or treating the foam with a perfluoroalkyl compound or the like.

However, the above (1) to (4) have their respective drawbacks as follows. In the method of (1) above, the foam tends to be closed-celled and has a large residual compression strain, so that it has poor durability when used as a sealing material or caulking material. Further, in the method (2) of adding waxes, coal tar, asphalt, etc. to the foam raw material, it becomes difficult for the raw material components to be compatible with each other, and the cell diameter, cell distribution, etc. become non-uniform. In addition to the above materials, including plasticizers, etc., the compatibility with foam is poor,
It leaches onto the foam surface in a relatively short period of time, the foam surface is soiled, and the waterproof effect is not stably maintained.

Further, in the method of using the specific polyol and the foam stabilizer of the above (3), the foam becomes heterogeneous and the water absorption varies, and a sufficient waterproof effect cannot be obtained.
In addition, the method (4) generally requires complicated heating and pressure processing at the time of treatment, and those not subjected to the treatment tend to reduce the waterproof effect.

[0006]

DISCLOSURE OF THE INVENTION The present invention provides a waterproof resin that has good characteristics such as residual compression strain originally required by a waterproof resin foam and that maintains stable waterproofness for a long period of time. An object is to provide a foam.

[0007]

The first invention is to foam and cure a foamable composition containing a polyisocyanate, a compound having at least two active hydrogen groups of 1 or 2 and a foam stabilizer. In the resin foam thus obtained, at least one of the above compounds has a main chain consisting essentially of carbon-carbon bonds, and the foamable composition contains carbon atoms at one end or in the middle. It has 6 or more hydrocarbon groups, and at the other end, one active group that reacts with the isocyanate group contained in the above polyisocyanate or one active group that reacts with the active hydrogen group contained in the above compound (these groups). The active group contains a terminal monofunctional compound having a terminal carbon atom or a carbon atom adjacent to the terminal carbon atom.) To impart waterproofness to the resin foam. .

In the present invention, each component constituting the above-mentioned "foamable composition" is conventionally "excluding the above-mentioned" compound having at least two active hydrogen groups "(hereinafter referred to as a polyfunctional compound). What is used for producing the "resin foam" can be used without particular limitation. As those components, polyisocyanate, a foaming agent, a foam stabilizer, a catalyst, and the like, and if necessary, a plasticizer, a flame retardant, a filler,
Antioxidants and other additives are used.

Examples of the above-mentioned "polyisocyanate" include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), polymeric MDI, naphthalene diisocyanate, paraphenylene diisocyanate, xylene diisocyanate (XDI), tetramethyl xylene diisocyanate, dimethyl diphenyl diisocyanate and the like. Aromatic polyisocyanate, hexamethylene diisocyanate, hydrogenated MDI, isophorone diisocyanate, lysine diisocyanate, hydrogenated X
DI, polyisocyanates such as aliphatic polyisocyanates such as cyclohexyl diisocyanate, and modified products thereof can be used. Among these, especially TD
I, MDI and their modified forms are preferred.

As the polyfunctional compound, one kind or two or more kinds are used, and at least one of them is
"A main chain consisting essentially of carbon-carbon bonds"
(Hereinafter, referred to as a hydrophobic polyol). Examples of such polyfunctional compounds include “polydiene-based polyols, castor oil-based polyols, polyolefin-based polyols and liquid chloroprene-based polyols” as in the second invention, and these may be used alone. Good, or two or more kinds may be used in combination. The main chain consisting essentially of carbon-carbon bonds means that the main chain does not contain a repeating unit such as an ether bond or an ester bond.
For example, it means a saturated or unsaturated long-chain alkylene group and the like.

All of the polyfunctional compounds may be hydrophobic polyols, but in view of the compounding purpose of improving the compatibility with the terminal monofunctional compound, the proportion of the hydrophobic polyol used is the terminal monofunctional compound. To 1 part by weight of the volatile compound,
It may be 1 part by weight or more, preferably 3 parts by weight or more.
If the amount used is 10 parts by weight, the purpose of improving the compatibility can be sufficiently achieved, and it is not necessary to add a larger amount.
As in the sixth aspect, it is preferable to add 1 to 10 parts by weight. If the amount of the hydrophobic polyol used is less than 1 part by weight,
Especially at low temperatures such as winter, it is difficult to uniformly mix the both, and after mixing, a monofunctional terminal compound may be deposited over time, which may affect the foam production process and the quality of the resulting foam. Is also not preferable.

As the polyfunctional compound other than the above-mentioned hydrophobic polyol, polyols, polyamines and the like which have been conventionally used for producing polyurethane foams can be used.
Examples of the polyol include polyether polyol, polyester polyol, and modified products thereof, and examples of the polyamine include monomolecular diamine, triamine, aromatic diamine, and polyether polyamine in which the end of the polyether is an amino group. These polyfunctional compounds may be used alone or in combination of two or more such as polyol and polyamine.

The above-mentioned polyether polyol can be obtained by randomly and block-wise addition-polymerizing alkylene oxide with a starting material having two or more active hydrogen groups in the presence of a basic catalyst. For example, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol,
Sucrose, polyols such as saccharol, ethylenediamine, active hydrogen compounds such as polyamines such as tolylenediamine, ethylene oxide, propylene oxide,
Examples thereof include those obtained by addition-polymerizing alkylene oxides such as trimethylene oxide and 3,3-dimethyltri (methylene) oxide. Further, a so-called polymer polyol obtained by graft-polymerizing acrylonitrile, styrene or the like to these, or a polyether polyol obtained by ring-opening polymerization or copolymerization of a cyclic ether such as tetrahydrofuran or dioxane can be used.

Examples of the polyester polyols include ethylene glycol, diethylene glycol, propylene glycol, butanediol, 1,6-
Hexanediol, 2,5-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerin,
Obtained by condensing low molecular weight polyols such as sorbitol and sucrose with carboxylic acids such as succinic acid, adipic acid, maleic acid, fumaric acid, phthalic acid, isophthalic acid, succinic anhydride, maleic anhydride, and phthalic anhydride. Other than
Examples include lactone-based polyols such as ε-caprolactone ring-opening polymer and β-methyl-δ-valerolactone ring-opening polymer.

Examples of the above-mentioned "terminal monofunctional compound" include "monoisocyanate, monoalcohol and monoamine" as in the third invention, and the "hydrocarbon group" thereof.
May be a linear group or a branched group, and may be a saturated group or an unsaturated group. Further, it may be an aromatic group, an alicyclic group or a group containing these groups. The terminal monofunctional compound may have one of these various types of hydrocarbon groups, or may be a mixture of two or more types of hydrocarbon groups.

The number of carbon atoms in the hydrocarbon group is preferably from 6 to 48, particularly preferably from 8 to 22, and these are appropriately used in consideration of the required waterproof property and ease of handling. If the carbon number is less than 6, the waterproofness of the resin foam obtained will be insufficient, and if it exceeds 48, the viscosity will be high and the resin will easily solidify at a slightly low temperature, which is not preferable. Further, as the terminal monofunctional compound, one kind of the compound having the above-mentioned "one active group capable of reacting with an isocyanate group or an active hydrogen group" may be used, and various compounds according to claim 3 You may use 2 or more types together.

The term "terminal monofunctional compound" means that a compound having a plurality of molecular terminals has the active group bonded to only one of the plurality of molecular terminals. In the middle part other than, for example, -NH-, -O-,
A compound having a group such as -S-, -CO- and -N (R)-(R is alkyl) is also included. In addition, at least one of the hydrocarbon groups bonded to both sides of these groups may have 6 or more carbon atoms.

Examples of the above-mentioned "monoisocyanate" include octadecyl isocyanate and monoisocyanates derived from a mixture of hexadecylamine and octadecylamine. In addition, the above "monoalcohol"
The 1-octanol, 1-decanol, lauryl alcohol, oleyl alcohol, other branched higher alcohols and distally -O -, - mono-alcohols having S- or the like (e.g., ROCH ₂ -CH ₂ -OH, etc.) However, as the above-mentioned “monoamine”, octylamine, laurylamine, octadecylamine and —O on the terminal side are further included.
Examples thereof include monoamines having-, -S- and the like.

The terminal monofunctional compound is prepared by mixing the polyisocyanate as the main component with the polyfunctional compound such as polyol and polyamine, and the monoisocyanate is usually added to the polyisocyanate component in advance, and the monoalcohol and the monoamine are excluded. Usually in addition to polyfunctional compounds, then those 2
The components may be mixed and stirred to prepare a foamable composition, which may be foamed and cured to form a resin foam, or the foamable composition may be stirred or mixed, or after stirring, mixing, foaming and curing reaction. May be added during the process.

Since each of the terminal monofunctional compounds has a long-chain hydrocarbon group, it is usually less reactive than the main component polyisocyanate and the polyfunctional compound, and may be mixed before or immediately after mixing the main components. The monofunctional terminal compound does not react preferentially even when added to, but when a monofunctional compound with relatively high reactivity is used, the main components are mixed and stirred to form a foam. It is preferable to add it while the reaction of (1) is progressing because the main component reacts more reliably in advance.

The compounding amount of the terminal monofunctional compound is 0.1 to 35 parts by weight, preferably 0.1 to 25 parts by weight, when the polyfunctional compound is 100 parts by weight as in the fifth invention. The range of 0.3 to 10 parts by weight is particularly preferable. The amount of the compound, considering the number of carbon atoms of the hydrocarbon group of the terminal monofunctional compound to be added, the type of functional group, and the difference in reactivity with the main component polyisocyanate and the polyfunctional compound, the purpose, It may be determined in an appropriate amount depending on the required waterproof property and the like.

When the amount is less than 0.1 parts by weight, sufficient waterproofness cannot be obtained, and when the amount is more than 35 parts by weight, formation of the foam itself becomes difficult, and physical properties of the obtained foam are difficult. However, the characteristics originally possessed by the foam are impaired, which is not preferable. Even if a normal foam is obtained, the terminal monofunctional compound may be incorporated into the foam unreacted. In that case, a conventionally known waterproof foam physically containing a hydrophobic material is used. Similarly, the monofunctional terminal compound may be gradually leached from the foam surface over time, and the foam surface may be soiled, which is not preferable.

In the present invention, the use of the hydrophobic polyol greatly improves the compatibility between the monofunctional terminal compound and the main component such as polyisocyanate and polyol, or the flame retardant and the filler. Functional compounds, for example,
The compatibility may be further improved by preliminarily dissolving or dispersing in a plasticizer and / or a solvent such as methylene chloride or cellosolve acetate. In general, higher alcohols having a higher molecular weight have a higher melting point and are more difficult to handle, so plasticizers such as tricresyl phosphate and tris-β-chloropropyl phosphate should be mixed in the required amounts. Is preferred.

Further, in order to further improve the waterproofness of the resulting waterproof resin foam, the main components such as polyisocyanate and polyols other than the hydrophobic polyol are those which are slightly more hydrophobic than the hydrophilic ones. It is preferable that the foam surface area be as large as possible because the waterproof effect is large. Therefore, it is preferable that the foam has a smaller cell diameter.

As the above-mentioned "foam stabilizer", a silicone-based one is often used, and for example, a dialkylpolysiloxane copolymer (a), a polysiloxane / polyoxyalkylene block copolymer (b) and the like are used. It (B) is composed of a polysiloxane part and a polyoxyalkylene part, and the polysiloxane part is often composed of dimethylpolysiloxane. Such a copolymer stabilizes the waterproof resin foam. Can be molded. still,
A typical structure of the above (b) is as shown in Formula 1.

[0026]

Embedded image

In the above formula (1), a methyl group at the terminal or the middle of the molecule or hydrogen in R may be substituted with a hydroxyl group, an amino group or the like to give hydrophilicity. In the copolymer (b), in order to obtain an excellent foam-controlling effect, it is preferable that both the polysiloxane moiety and the polyoxyalkylene moiety have a high molecular weight, and m
When + n is 10 or less, the foam control effect is poor and usually m + n is 2
The thing of about 5-100 is used.

Further, the higher the silicon content of the copolymers (a) and (b) is, the more hydrophobic the copolymers are. Therefore, in the copolymer (b), the siloxane skeleton portion is longer than the oxyalkylene chain. More preferred, in other words,
If a foam stabilizer made of the copolymer (b) having a large (m + n) / (m + n + a + b) ratio is used, a resin foam having higher waterproofness can be obtained. More specifically, the fourth
As in the invention, when the silicon content obtained by the following measuring method is in the range of 5% or more, particularly 10 to 25%, a waterproof resin foam having a lower water absorption can be obtained.
In the present invention, it is preferable to use a hydroxyl group-terminated and / or amino group-terminated copolymer in the copolymers (a) and (b).

Silicon content of copolymer: The copolymer was dissolved in benzene and the infrared absorption spectrum was measured. on the other hand,
Dimethyl polysiloxane (Tore Silicon Co.,
For the grade name "SH200"), the infrared absorption spectrum of a solution of the same concentration and the same solvent was measured, and the wave number was 800c.
The absorption peak areas at m ⁻¹ were compared. Silicon content = (absorption peak area of foam stabilizer / absorption peak area of dimethylpolysiloxane “SH200”) × 3
7.8 (%)

[0030]

In the present invention, waterproofness is imparted by chemically bonding the terminal monofunctional compound to the resin foam being produced. The terminal monofunctional compound has a hydrocarbon group having 6 or more carbon atoms at one end or an intermediate portion, and one active group that reacts with an isocyanate group or an active hydrogen group bonded to a carbon atom on the other molecular end or adjacent to it. Since it has a structure, its reactivity is usually lower than that of polyisocyanate and polyol which are main components. Therefore, the reaction of the main component proceeds, and when the foam is being formed, or near the end of foam formation, it reacts with an isocyanate group or an active hydrogen group near the surface of the foam, and a urethane bond, a urea bond, an alohanate bond, Alternatively, it is chemically strongly bonded to the foam by a biuret bond or other bond, and the foam surface is covered with a long-chain hydrocarbon group having strong hydrophobicity.

Since the monofunctional terminal compound is bonded to the foam surface as described above, a sufficient waterproofing effect can be obtained even when the amount of the monofunctional compound used is very small. Once bonded to the active hydrogen groups such as isocyanate groups or hydroxyl groups or amino groups on the foam surface, the bond is extremely stable, and the foam surface has a long-chain hydrocarbon group or aromatic group with strong hydrophobicity. A large number of etc. will exist stably. Therefore, unlike a conventional technique in which a large amount of a hydrophobic material, a water repellent, or the like is physically incorporated into a foam, the waterproof resin foam of the present invention has no deterioration in physical properties, No change in waterproofness is observed even when exposed to sunlight, and excellent waterproofness is maintained extremely stable over a long period of time.

Further, in the present invention, since the polyol component contains a specific hydrophobic polyol which is excellent in compatibility with the terminal monofunctional compound, it is solidified at a low temperature such as in winter and the solubility is lowered. The monofunctional compound can be easily dissolved in the polyol component. for that reason,
The preparation of the foamable composition and the production of the foam are easy even at a low temperature, and the quality of the obtained product is further improved. Furthermore, since the range of usable terminal monofunctional compounds is expanded, a resin foam having a wide range of waterproof properties and physical properties can be easily obtained.

[0033]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. (1) Components used in Examples and Comparative Examples 1) Polyol: Polyether polyol obtained by addition-polymerizing propylene oxide with glycerin (hydroxyl value; 56) Dimer acid-based polyol, manufactured by Kao Corporation, trade name "EDIFORM E -408 "(hydroxyl value: 80)

Castor oil-based polyol, manufactured by Ito Oil Co., Ltd., trade name "URIC H-30" (hydroxyl value: 16
0) Polybutadiene-based polyol, manufactured by Idemitsu Petrochemical Co., Ltd., trade name "R-45HT" (hydroxyl value; 46.6) Liquid chloroprene-based polyol, manufactured by Denki Kagaku Kogyo Co., Ltd., trade name "LCR FH-050" (hydroxyl group Value; 2
4) Polyolefin polyol, manufactured by Mitsubishi Kasei Co.,
Product name "Polytail HA" (hydroxyl value: 48)

2) Blowing agent: water 3) Catalyst: 3 of triethylenediamine / dipropylene glycol
3/67 (weight ratio) mixture, DABCO, trade name "33LV" Amine-based, Union Carbide, trade name "NIA"
X A1 "tin-based, stannous octylate Kao Co., Ltd., trade name" Caolizer NO.3 "Wako Pure Chemical Industries, Ltd., N-methylmorpholine

4) Foam stabilizer: Polyalkyl siloxane copolymer, manufactured by Nippon Unicar Co., Ltd., trade name "Y6827", manufactured by Toray Dow Corning Co., Ltd., trade name "SH19"
4 ”Nippon Unicar Co., Ltd., trade name“ L532 ”5) Flame retardant: Daihachi Chemical Co., Ltd., trade name“ CRP ”

6) Terminal monofunctional compound: manufactured by Kao Corporation, octadecylamine, Hodogaya Chemical Co., Ltd., octadecyl isocyanate, Tokyo Kasei Co., Ltd., 1-octanol Sanyo Kasei Co., Ltd., trade name "Emulmine 40".
(Higher alcohol) Tokyo Kasei Co., Ltd., octylamine amine modified silicone, Toray Dow Corning Co., Ltd., trade name “SF8417” 7) Tolylene diisocyanate: Nippon Polyurethane Co., Ltd., trade name “T-80” [2 , 4-TDI / 2,6
-80/20 (weight ratio) mixture of TDI]

(2) Foamable Compositions of Examples and Comparative Examples Examples 1 to 5 are examples in which octadecylamine was compounded as a terminal monofunctional compound and the kind of the hydrophobic polyol was changed. Nos. 6 to 10 are examples in which a liquid chloroprene type was used as the hydrophobic polyol and the terminal monofunctional compound was changed. In addition, in Example 11, Example 4 is used.
In the example, the mixing temperature of the foam raw material was set to a low temperature of 10 ° C. (all other examples were mixed at 23 ° C.).

Furthermore, in Examples 12 to 20, in the formulation of Example 4, the foam stabilizer was a copolymer represented by the formula (1) (provided that R is hydrogen), and the hydroxyl value and silicon thereof were used. This is an example of changing the content rate. On the other hand, Comparative Examples 1 to 3 are examples in which polyurethane foams were produced without using any terminal monofunctional compound.

The respective formulations of Examples 1 to 5, Examples 6 to 10, Examples 12 to 16 and Examples 17 to 20 are shown in Table 1, Table 2, Table 3 and Table 4, respectively, and comparisons are made. An example formulation is shown in Table 5. The values in the table are all 10 for polyol.
Represents parts by weight when the amount is 0 parts by weight.

(3) Method of evaluating waterproofness The water absorption rate was determined as an index of waterproofness. Water absorption rate is 50 x
A 50 × 20 (thickness) mm test piece was compressed at a compression rate of 50% in the thickness direction (thus, the thickness is 10 mm),
The weight increase when immersed in water 10 cm below the water surface for 24 hours at a water temperature of 23 ° C. was measured.
It is expressed based on the volume of the test piece at the time of% compression. [Water absorption (%) = {weight change before and after immersion (g) / volume of test piece at 50% compression (cm ³ )} × 100]

The water absorption of the resin foam of Example 11 measured by the above method was 3.6%, and even if the raw materials were mixed at a low temperature, the waterproof property was hardly affected. There wasn't.

The water absorption rates of Examples and Comparative Examples other than Example 11 are also shown in Tables 1, 2, 3, 4 and 5, respectively. For Example 4, the water absorption rate after heating for 72 hours and 168 hours in a constant temperature bath set at 70 ° C. was also measured. The results are also shown in Table 1. In addition, in order to confirm the influence of the addition of the terminal monofunctional compound on the original properties of the polyurethane foam, Example 4 was used.
And 6 and the physical properties of Comparative Example 1 were measured. Table 6 shows the results. In addition, the measuring method of each physical property is as follows.

Density, impact resilience and hardness: JIS K
6401 Tensile Strength, Tensile Elongation and Tear Strength: JIS K63
01 Compressive residual strain: JIS K6401

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

[Table 3]

[0048]

[Table 4]

[0049]

[Table 5]

[0050]

[Table 6]

According to the results shown in Table 1, in Example 1 in which the total amount of polyol was a dimer acid type polyol, and in Examples 2 to 5 in which 20 parts by weight of various hydrophobic polyols were used in combination with a general-purpose polyether polyol, water absorption was observed. The maximum rate is 4.
It is 3%, which shows that the foam is extremely excellent in waterproofness. Further, according to the results of Table 2, Examples 6 to 10 in which 20 parts by weight of liquid chloroprene-based hydrophobic polyol were used and various terminal monofunctional compounds were blended
However, the maximum water absorption is 4.8%, which is also a foam having very excellent waterproofness.

Further, according to the results of Tables 3 to 4, when the silicon content of the foam stabilizer is changed, the water absorption tends to increase as the content decreases, but the lowest content Even in Example 20, it is slightly less than 20%, which is remarkably excellent as compared with each comparative example, and when the silicon content is 5% or more, the water absorption rate is 10% or less, and when the content rate exceeds 10%. The water absorption rate is about 5% or less, which shows that the water absorption property is very excellent.

On the other hand, according to the results shown in Table 5, in Comparative Examples 1 to 3 in which the monofunctional terminal compound was not blended at all, the water absorption rate was slightly over 100%, which was higher than that in each Example. It turns out that the sex is extremely poor. Further, in the present invention, even when the obtained foam is exposed to a high temperature (70 ° C.) for a long time, the water absorption rate is increased, but it is far more than the absolute value of the water absorption rate in each of the above Comparative Examples. It can be seen that it is excellent and has high durability in waterproof performance. Further, Table 6
According to the results of 1, the deterioration of the physical properties was hardly seen by blending the terminal monofunctional compound, and in the present invention, the excellent properties of the foam were realized without impairing the properties of the foam in practical use. I understand.

The present invention is not limited to the specific examples described above, and various modifications may be made within the scope of the present invention depending on the purpose and application. For example, if the active group is attached to the carbon atom next to the end of the terminal monofunctional compound, the end will be not only a methyl group,
It may be a long-chain hydrocarbon group having 6 or more carbon atoms as long as it reacts, and, for example, -NH-, -O may be present in the middle portion thereof.
It may have a group such as-, -S-, -CO- and -N (R)-, and these have low reactivity and are considered to bind to the foam surface, and are more preferable for improving waterproofness. .

Further, cellosolve acetates, naphtha,
Organic solvents such as xylene and toluene, ketones such as methyl ethyl ketone and acetone, monoalcohols such as methanol and butanol, and esters with organic carboxylic acids,
Polybasic acid esters such as DBP, fatty acids having 8 or more carbon atoms such as stearin and / or salts thereof, and individual products or mixtures such as essential oils, etc., within a range that does not impair the inherent properties of the foam, usually 100 parts by weight of the foam. 0 for the department.
The waterproof performance can be further enhanced by blending in an amount of about 5 to 5 parts by weight.

[0056]

EFFECT OF THE INVENTION In the waterproof resin foam of the first invention, since the terminal monofunctional compound having a very strong hydrophobic long-chain hydrocarbon group is chemically bonded to the foam surface,
As described in the seventh aspect, excellent waterproof performance is realized, and it is stably maintained for a long period of time. Further, even when the foam is exposed to a high temperature environment, a much higher waterproof effect is maintained as compared with the waterproof performance of the conventional technique. Furthermore, since a hydrophobic polyol having excellent compatibility with the terminal monofunctional compound described in the third invention such as the polyol described in the second invention is used as the polyol, even when the foam raw material is prepared at a low temperature, The foam can be obtained without any problem, and the excellent waterproofness is maintained as it is.

In addition, the kind of the terminal monofunctional compound is not limited by using a suitable amount of the hydrophobic polyol having excellent compatibility with the terminal monofunctional compound as described above, as in the sixth invention. It is possible to easily control the types of long-chain hydrocarbon groups bonded to the foam surface, the amount of bonding, etc., and it is possible to obtain a waterproof foam having appropriate waterproofness depending on the application and purpose. This waterproof property can also be adjusted by using a foam stabilizer containing a specific amount of silicon as in the fourth invention.

Further, in the present invention, as can be seen from the fifth invention and each of the examples, a sufficient waterproofing effect can be obtained even if the compounding amount of the terminal monofunctional compound is small. Therefore, unlike conventional products, a large amount of hydrophobic material, etc. physically incorporated into the foam will not seep out to the surface of the foam over time and the surface of the foam will be contaminated. It can also be used as a packing material for disliked parts, and can also be used without problems as a material such as a sealing material that is attached and fixed with a double-sided adhesive tape. Further, unlike the prior art, there is no problem that foaming is difficult due to the use of a large amount of oily material, in other words, foam is difficult to manufacture.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area C08G 101: 00)

Claims (7)

[Claims] 1. A resin foam obtained by foaming and curing a foaming composition containing a polyisocyanate, a compound having at least two active hydrogen groups of 1 or 2 and a foam stabilizer, wherein: At least one of the compounds has a main chain consisting essentially of carbon-carbon bonds, and the foamable composition has a hydrocarbon group having 6 or more carbon atoms at one end or in the middle thereof. , At the other end, one active group that reacts with an isocyanate group contained in the above polyisocyanate, or one active group that reacts with an active hydrogen group contained in the above compound (these active groups are the terminal carbon atoms or the A waterproof resin foam, comprising a terminal monofunctional compound having a carbon atom adjacent to a terminal carbon atom), to impart waterproofness to the resin foam. 2. The compound having at least two active hydrogen groups is one or more selected from polydiene-based polyols, castor oil-based polyols, polyolefin-based polyols and liquid chloroprene-based polyols. Waterproof resin foam. 3. The waterproof resin foam according to claim 1, wherein the terminal monofunctional compound is one kind or two or more kinds selected from monoisocyanate, monoalcohol and monoamine. 4. The foam stabilizer according to claim 1, wherein the foam stabilizer is a polysiloxane / polyoxyalkylene block copolymer, and the silicon content of the copolymer measured by the following method is 5% or more. Waterproof resin foam. Silicon content of copolymer: 0.5 g of the copolymer is dissolved in 10 cc of benzene, and the infrared absorption spectrum is measured. Dimethyl polysiloxane prepared to the same concentration as the above copolymer (made by Toray Silicon Co., Ltd., grade name "S
The infrared absorption spectrum of the benzene solution of "H200") is measured. Wavenumber of infrared absorption spectrum of above and 800 cm
The absorption peak area at ^-1 is calculated, and the silicon content of the copolymer is calculated by the following formula. Silicon content rate (%) = (absorption peak area of copolymer /
SH200 absorption peak area) × 37.8 The coefficient 37.8 is the silicon content (%) of dimethylpolysiloxane determined from the atomic weight based on the chemical formula. However, the degree of polymerization of the siloxane skeleton is at least 100. 5. The terminal monofunctional compound is blended in an amount of 0.1 to 35 parts by weight based on 100 parts by weight of the compound having at least two active hydrogen groups. The waterproof resin foam according to item 1. 6. 1 to 10 parts by weight of the compound having at least two active hydrogen groups, whose main chain consists essentially of carbon-carbon bonds, relative to 1 part by weight of the terminal monofunctional compound. The waterproof resin foam according to any one of claims 1 to 5, which is mixed in parts. 7. The water absorption of the waterproof resin foam measured by the following method is 1.5 to 20%.
7. The waterproof resin foam according to any one of 6 to 6. Water absorption rate: A test piece of 50 × 50 × 20 (thickness) mm was compressed at a compression rate of 50% in the thickness direction (thus, the thickness is 10 m).
m. ), The weight increase when immersed in water 10 cm below the water surface for 24 hours at a water temperature of 23 ° C., and the rate of this weight increase is expressed based on the volume of the test piece at 50% compression. [Water absorption (%) = {weight change before and after immersion (g) / 5
Volume of test piece at 0% compression (cm ³ )} × 100]