JPH0138152B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a sealing material with excellent waterproof properties, and more particularly to a soft to semi-rigid open-cell polyurethane foam sealing material with excellent waterproof properties. Conventionally, as a waterproof foam sealing material, one in which polyurethane foam is impregnated with a waterproofing agent such as asphalt is known. The polyurethane foam sealing material can be produced by (1) cutting open-cell polyurethane foam to an appropriate thickness, impregnating it with a volatile solution of asphalt, and then drying it; (2) the method described in (1) above. It was manufactured by using asphalt suspension water instead of the volatile asphalt solution. Both methods (1) and (2) above involve impregnation and drying steps, which are not only cumbersome to operate and have poor productivity, but also require the foam cell size and air permeability of the open-cell polyurethane foam to be sufficiently large. Otherwise, asphalt cannot be uniformly impregnated into the inside, and if the foam itself is large, it is difficult to impregnate the inside with asphalt. Furthermore, method (1) requires a large amount of volatile solvent to dissolve asphalt, which poses a risk of air pollution, harm to the human body, and fire, and also reduces productivity as it takes a long time to dry the solvent. On the downside, there are many problems such as staining the mating material when using it, being sticky when handling it, being highly sensitive to temperature, decreasing its hardness in the summer, and slowing down the recovery speed after compression. Ta. In addition, although method (2) above can overcome the disadvantages of method (1) due to the use of volatile solvents, it requires a long time for drying, has poor productivity, and impregnates asphalt. Therefore, it is necessary to use a surfactant, which remains in the sealant even after drying and is activated when it comes into contact with water, which has the drawback of reducing waterproof properties. The present invention has been made to provide a sealing material having excellent waterproof properties without the above-mentioned drawbacks. The inventors of the present invention previously conducted research to eliminate the drawbacks of conventional methods, and found that (1) the boiling point at normal pressure is 200°C or higher;
(2) When a substance consisting essentially of hydrocarbons with a melting point or softening point of 150°C or below is mixed into a polyurethane raw material and the air permeability is below a certain level, it can be used as a waterproof sealing material; (2) Especially as a polyol. It has been found that waterproof properties can be improved when polydiene polyols, dimer acid polyols, and castor oil polyols are used alone or as a mixture thereof. As a result, it was possible to eliminate the disadvantage of impregnation with fillers such as asphalt through post-treatment, and also succeeded in obtaining an excellent waterproof sealing material. Furthermore, as a result of research, it was found that the foam stabilizer used in the production of polyurethane foam has a significant effect on the waterproofness (water leakage resistance) of polyurethane foam. It has been known that organosilicon compounds are effective as foam stabilizers for polyurethane foams. In the production of polyurethane foams for cushions, suitable organosilicon compounds are used, such as polydimethylsiloxane-polyalkylene glycol block copolymers whose terminal ends are capped with acetyl, methoxy, ethoxy, or bitoxy groups. compounds are widely used. However, when using an organosilicon compound whose terminal end is capped with the above-mentioned group, the resulting polyurethane foam has a good foam regulating effect and a good cushion foam can be obtained, but the degree of hydrophobicity of the polymer It was found that the contact angle with water decreased and the material became so hydrophilic that it absorbed water by itself, making it unable to prevent water leakage at all even under low water pressure. On the other hand, it has been found that when an organosilicon compound based on polydialkylsiloxane containing primary or secondary amino groups is used, it becomes water repellent and prevents water leakage under constant water pressure. Although the reason for having these characteristics is not clear, it is thought to be as follows. Polyurethane foam contains polar groups such as urethane bonds, ester bonds, and urea bonds, and is itself hydrophilic. For example, polyurethanes of tolylene diisocyanate and ethyl alcohol are water-soluble, and polyether polyols such as polyethylene polypropylene ether are also hydrophilic. When producing polyurethane foam, when using an organosilicon compound whose terminal end is capped with an acetyl group, methoxy group, ethoxy group, butoxy group, etc., the surfactant effect it has during foam regulation remains unchanged even after the foam is produced. Because it has an interfacial effect, it has a high affinity for water, and its hydrophilicity is even greater than that of foams produced without the addition of these compounds. On the other hand, when using an organosilicon compound based on polydialkylsiloxane having primary or secondary amino groups, it reacts with polyisocyanate during foam production and copolymerizes into the polyurethane polymer chain. It is thought that this improves hydrophobicity. However, the amount of amino groups or acetyl groups in this silicon is small compared to the number of hydroxyl groups in the raw materials used, and considering that the amount added is about 1 part by weight per 100 parts by weight of polyol, there is a difference in waterproofness. It is extremely surprising that it has grown this large. An example of a comparison of waterproof properties as a sealing material when the organosilicon compound used in the present invention and other organosilicon compounds are used as a foam stabilizer is as follows.

【table】

[Table] However, Polyol A: Polyether polyol with a molecular weight of 3000, made by adding propylene oxide to glycerin Polyol B: Polyester polyol with a hydroxyl value of 60.6 and an acid value of 1.2 synthesized from trimethylolpropane, diethylene glycol, and adipic acid Blending recipe: 100 parts of polyol , 3 parts of water, tolylene diisocyanate NCO/OH equivalent ratio 1.02 In other words, the sealing material of the present invention is different from conventionally known sealing materials in that it does not easily deteriorate in waterproofness even though it has high air permeability. be. As mentioned above, this is not clear, but the hydrophobicity of the polyurethane foam is sufficiently increased because the amino groups in the silicone foam stabilizer and polyisocyanate react strongly and without any unreacted components. it is conceivable that. Next, as representative compounds of the primary and secondary amino group-containing organosilicon compounds used in the present invention, the following compounds can be mentioned. (However, R represents a divalent organic group, x represents an integer of 0 to 100 or more, and R' represents H or a monovalent organic group) (However, R is a divalent organic group, R' is H or a monovalent organic group, X is an integer of 0 to 100 or more,
Y represents an integer from 1 to 100 or more. ) (However, R is a divalent organic group, R' is H or a monovalent organic group, X is an integer of 0 to 100 or more,
Y represents an integer from 1 to 100 or more. ) (However, R, R', R are H or a monovalent alkyl group, R'' is a divalent organic group, n is an integer from 2 to 4,
p, q, r, z represent integers. ) (However, R and R are H or a monovalent alkyl group.
R', R'' are divalent organic groups, n is an integer of 2 to 4, X,
Y and Z represent integers. ) In the above formulas (1) to (5), a part of the methyl group or alkyl group may be substituted with an aryl group. The amount of primary and secondary amino group-containing organosilicon compounds used in the present invention is preferably 0.1 to 10% by weight of the total reaction mixture, and these are reacted in advance with excess polyisocyanate and polyol before use. Alternatively, it may be added at the time of foaming using the so-called one-shot method. Polyols used in producing the sealant of the present invention include polyether polyols, polyester polyols, polydiene polyols,
Examples include castor oil polyol. However, when polydiene polyol, dimer acid polyol, or castor oil polyol is used as the polyol, it is not necessarily necessary to add a filler consisting essentially of hydrocarbons such as asphalt, and an excellent leak-resistant sealing material can be obtained. It is particularly preferred because it can be produced easily. These polyols may be used alone or in combination, and other general purpose polyethers or polyesters may be added. It is necessary to use the general-purpose polyol in an amount of 20 parts by weight or more per 100 parts by weight of the total polyol. However, if a foam is manufactured by mixing a filler, particularly a substance consisting essentially of hydrocarbons with a boiling point of 200°C or higher and a melting point or softening point of 150°C or lower at normal pressure, into the reaction raw materials, the waterproof property will be reduced. Therefore, it is preferable to mix this in order to obtain a sealant with excellent waterproof properties. When using polyether polyols and polyester polyols other than the above polyols,
In order to obtain a sealing material with excellent waterproof properties, a filler such as a substance that is essentially a hydrocarbon with a boiling point of 200°C or more and a melting point or a softening point of 150°C or less at normal pressure is mixed in advance into the reaction raw material. It is preferable to carry out the reaction. Polyether polyols include polyhydric alcohols such as ethylene glycol, glycerin, and trimethylolpropane, and addition polymerization of alkylene oxides or allyl oxides such as ethylene oxide, propylene oxide, butylene oxide, and styrene oxide to these polyhydric alcohols. Can be mentioned. However, the present invention is not limited thereto, and these can be used alone or as a mixture, and when ethylene oxide is addition-polymerized, the amount added is preferably less than 10 mol %. Examples of polyester polyols include compounds synthesized from polyhydric carboxylic acids such as adipic acid, phthalic acid, and succinic acid and polyhydric alcohols such as ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, and trimethylolpropane. However, it is not limited to these, and these can be used alone or as a mixture. Polydiene polyols include homopolymers or copolymers of diene compounds such as butadiene, isoprene, and chloroprene, or radical or anionic copolymers of these monomers and copolymerizable vinyl compounds such as styrene and acrylonitrile. Examples include hydroxyl group compounds, decomposition products of solid rubber containing diene components, and the like. However, the invention is not limited thereto, and these can be used alone or as a mixture. Dimer acid is a dibasic acid, in which two monobasic fatty chains (usually with 18 carbon atoms) are bonded bimolecularly through a carbon-carbon donor bond, resulting in a dibasic acid with twice the molecular weight. refers to acid. Typical compounds thereof are obtained by heating linoleic acid and oleic acid, and their structural formulas are as follows. Industrial methods for producing dimer acids include monomer acids, tribasic acids, and polymeric acids in addition to dimer acids. Mixtures of these may also be used in the present invention. Dimer acid derivative polyols include dimer acid polyesters, which are reaction products of dimer acids and short chain diols, triols, or polyols; dimer acids and polyalkylene glycols;
Reaction products with polyalkylene triols or long-chain polyols; reaction products obtained by reacting a mixture of dimer acid with other polycarboxylic acids such as adipic acid with the various diols, triols, or polyols; dimer acid and alkylene Mention may be made of reaction products with oxides or mixtures thereof. However, it is not limited to this. Examples of castor oil derivative polyols include:
Castor oil polyester; polyester obtained from mixed polycarboxylic acid of castor oil and other acids such as adipic acid; castor oil and ethylene glycol,
Reaction products of short-chain polyol mixtures such as 1,4-butanediol and glycerin with polycarboxylic acids; reaction products of castor oil and alkylene oxides, such as propylene oxide, ethylene oxide, butylene oxide, etc.; alkylene oxides of castor oil polyesters Mention may be made of addition polymers or mixtures thereof. However, it is not limited to this. The number average molecular weight of these dimer acids or castor oil derivative polyols or castor oil is approximately 600~
10,000, preferably 700-5,000. If it is a reaction product of dimer acid and short chain diol or triol, the number average molecular weight is 600 to 5000,
In particular, it is preferably 800 to 5000. Further, in the case of a reaction product of dimer acid or castor oil and alkylene oxide, the number average molecular weight is preferably 1000 to 5000. And, these average functional groups are 1.6 to 4.5, preferably 1.8 to 3.0. Examples of polyisocyanate compounds include:
Examples include tolylene diisocyanate, polyethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate, and hydrogenated polyethylene polyphenylene diisocyanate. These may be used alone or in mixtures. However, it is not limited to this. Among these, the waterproof property is particularly improved when polymethylene polyphenylene polyisocyanate is used. Boiling point at normal pressure added as filler is 200
Substances consisting essentially of hydrocarbons with a melting point of 150°C or higher or a softening point of 150°C or lower include, for example:
Paraffin, waxes, coal tar, asphalt, naphtha C ₄ ~ produced as a by-product during cracking
What is called petroleum resin, which is made by polymerizing _C11 distillate,
Examples include petroleum oils such as polybutene extension oil. However, it is not limited to this. Examples of fillers other than those mentioned above include plasticizers such as dibasic carboxylic acid esters, and animal and vegetable oils. Examples of the blowing agent include water; halogenated alkanes such as monofluorinated trichlormethane and dichlorinated methane; low boiling point alkanes such as butane and pentane; azobisisobutyronitrile that generates decomposed nitrogen gas, etc. It will be done. These may be used alone or in mixtures. However, it is not limited to this. Examples of the catalyst include tertiary amines and organic tin compounds, and typical examples thereof include triethylenediamine, triethylamine, n-methylmorpholine, n-ethylmorpholine, N,N,
Examples include N',N'-tetramethylbutanediamine, stannous octoate, and stannous dibutyllaurate. However, it is not limited to this. In addition to the above, crosslinking agents used in general polyurethane foams; fillers such as carbon black and calcium carbonate; ultraviolet absorbers; antioxidants, etc. can of course be mixed and used as appropriate. Furthermore, bituminous substances and tackifiers may be added for the purpose of improving softness, increasing adhesion to contact surfaces, reducing costs, etc. The polyurethane foam of the sealant of the present invention is formed using the above-mentioned raw materials, catalysts, blowing agents, etc. It can be produced by any of the conventionally known methods such as (1) prepolymer method, (2) one shot method, and (3) partial prepolymer method. As mentioned above, the water leakage resistance of polyurethane foam is influenced by the type of polyurethane raw material, whether or not a waterproofing agent is added, and the type of foam stabilizer, but is also influenced by the degree of air permeability. Its air permeability is
The air permeability (hereinafter referred to as air permeability) at a thickness of 10 mm is approximately 100 c.c./cm ² /sec or less, preferably approximately 30 c.c./cm ^{2 /} sec.
It must be less than sec. Adjustment of this air permeability depends on the amount and type of catalyst (for example, using a tin-based catalyst,
When the amount used is increased, the air permeability decreases. ), stirring conditions (varies significantly depending on blade shape and rotation speed), amount of dissolved air (less air permeability will be lower, higher air permeability will be higher), type and amount of blowing agent, etc.
Since it changes depending on the reaction temperature, etc., it is carried out by adjusting these. The waterproof property of a polyurethane foam can be determined by measuring the contact angle with water, and it is preferable that the contact angle is at least 75 degrees or more, preferably about 90 degrees or more. The air permeability referred to in the present invention is based on the Frangier type method of woven fabric air permeability test, and is based on the JIS-L-
1004, the thickness of the foam was 10 mm. The device used was air permeability tester No. 869 manufactured by Toyo Seiki Co., Ltd. The above contact angle means that a foam of approximately 10 mm thickness is sandwiched between aluminum foil at a temperature of 180 to 200°C and a pressure of 40°C.
This is the value measured using a contact angle meter after pressing at ~50 kg/cm ² into a film. As a contact angle meter, a Kyowa contact angle meter CA-A type (manufactured by Kyowa Kagaku Co., Ltd.) was used. The waterproof test was conducted using an outer diameter of 98 mm (vertical and horizontal) and an inner diameter of 68 mm (vertical and horizontal) as shown in Figures 1 and 2.
A rectangular sample 1 with a diameter of 10 mm and a thickness of 10 mm is sandwiched between two acrylic resin plates 2 and 3, and water is injected from the water injection pipe 5 provided in the center to change the water pressure (height of the water column). In addition, when sample 1 was sandwiched between two acrylic plates 2 and 3, the thickness of spacer 4 was changed and the compression ratio was changed to measure how many minutes after water started to leak after water was injected. . When using the sealing material obtained by the method of the present invention, it is preferable that the compression ratio is 20% or more. The reason for this is that, especially in the case of foam, the state of the compressed surface on the compressed surface is greatly affected and it is difficult to compress the foam uniformly. When compressed by 20%, water leakage due to the influence of the condition of the compressed surface can be prevented. As described above, conventional general-purpose polyurethane foam could not prevent water leakage no matter how much it was compressed, no matter how much the air permeability approached 0, or even when the water pressure was reduced, but with the method of the present invention, water leakage could not be prevented. The sealing material thus obtained has an excellent effect of preventing water leakage while having air permeability. Therefore, sealing materials such as automobile fender sealer, front pillar sealer, pentilator sealer, etc.
It can be effectively used as a sealing material for ships, refrigerators, etc. In the following examples, parts represent polymerized parts. Examples 1 to 3 Polyether polyol 100 with a molecular weight of about 3000 obtained by addition polymerizing propylene oxide to glycerin
1 part, 2.5 parts water, triethylenediamine (Dabco-
33LV Sankyo Air Products Co., Ltd.) 0.4 parts, stanas octate 0.5 parts, tolylene diisocyanate (mixing ratio of 2.4 and 2.6 isomers 80:20,
A polyurethane foam was produced by rapidly mixing 33.5 parts of T-80 (abbreviated as T-80) and 1 part of the following amino group-containing organosilicon compound as a foam stabilizer. The physical properties and waterproof properties of the obtained foam are shown in Table 1.

[Table] Comparative Example 1 Polydimethylsiloxane-oxyalkylene copolymer having an acetyl group at the end as a foam stabilizer
Foams were manufactured in the same manner as in Examples 1 to 3 except that one part of SH190 (manufactured by Toray Silicon Co., Ltd.) was used. Table 1 shows the physical properties and waterproof properties of the obtained foam.

[Table] As is clear from the results in Table 1, the waterproof properties of the foam obtained by the method of the present invention are significantly superior. Examples 4-5 Dimer acid polyester polyol obtained from dimer acid and diethylene glycol trimethylol propane (hydroxyl value 62.2, acid value 0.73 100
1 part, 2.0 parts water, triethylenediamine (Dabco-
33LV) 0.2 part, appropriate amount of stannous octate, 29.1 parts of tolylene diisocyanate (T-80), 1 part of SH3531 as a foam stabilizer, (Example 4) 0.5 part of FZ319,
A foam was manufactured using (Example 5). Table 2 shows the physical properties of the obtained foam. Comparative Examples 2 to 3 1 part of polydimethylsiloxane-oxyalkylene block copolymer (SH190, manufactured by Toray Industries, Inc.) having an acetyl group at the end as a foam stabilizer (Comparative Example 2), polydimethylsiloxane-oxy having a butoxy group at the end Alkylene block copolymer (F258,
A foam was produced in the same manner as in Examples 4 and 5 except for using 1 part of (Comparative Example 3) (manufactured by Shin-Etsu Chemical Co., Ltd.). Table 2 shows the physical properties of the obtained foam.

[Table] As is clear from the results in Table 2, the foam density,
Even if the air permeability is the same, the waterproofness of the foam obtained by the method of the present invention is significantly higher than that of the comparative example. Example 6 The hydroxyl group content with a hydroxyl group at the end is
Polybutadiene homopolymer (manufactured by Alco Chemical Co., Ltd., Poly
BDR-45HT) 100 parts, water 2.0 parts, triethylenediamine (Dabco-33LV) 0.2 parts, stannath octate 2.0 parts, tolylene diisocyanate (T-80)
A foam was prepared from 27.5 parts and 1 part of DC536 as a foam stabilizer. Foam density 0.0432, air permeability 1.5
It was cc/cm ² /sec. Comparative Example 4 Example 6 except that SH190 was used as a foam stabilizer
A foam was manufactured in the same manner as above. The foam density is 0.041 g/cm ³ and the air permeability is 2.3 cc/cm ² /sec. Table 3 shows the results of testing the waterproof properties of the foams manufactured in Example 6 and Comparative Example 4 by changing the compression ratio and water pressure.
Shown below.

[Table] As is clear from the results in Table 5, the foam produced by the method of the present invention exhibits excellent waterproof properties even when the compression ratio and water pressure are changed, but the foam produced by the method of the present invention exhibits excellent waterproof properties regardless of the compression ratio. When the temperature rises, water leaks rapidly. Example 7 100 parts of refined castor oil (hydroxyl value 162), 2.0 parts of water,
2 parts of trichloromonofluoromethane, 0.5 part of N-ethylmorpholine, 0.1 part of triethylenediamine (Dabco-33LV), 44.5 parts of tolylene diisocyanate (T-80), 1 part of SH3531 as a foam stabilizer.
A urethane foam was manufactured from the above. After the foam was cured, it was lightly crushed. The density of the obtained foam was 0.0419 g/cm ³ Air permeability 15.1 cc/cm ² /sec Table 4 shows the water leakage start time when the water pressure was changed as the waterproof property at 75% compression. Example 8 69.27 parts of polymethylene polyphenylene polyisocyanate MDI-CR (Mitsui Nisso Urethane Co., Ltd.) was used as the isocyanate, an appropriate amount of catalyst was used, and 1 part of the foam stabilizer of Example 7 was used. A foam was manufactured in the same manner as in Example 7. The obtained foam density was 0.0487g/cm ³ and the air permeability was 17.6cc/cm 3 .
Table 4 shows the waterproof properties in cm ² /sec.

[Table] From the results in Table 4, it is clear that the foam produced by the method of the present invention has excellent waterproof properties.
Moreover, when the polymethylene polyphenylene polyisocyanate of Example 8 is used, the waterproof property is further improved. Example 9 In addition to the formulation of Example 4, 15 parts of petroleum resin, Neopolymer S (manufactured by Nippon Petrochemical Co., Ltd.),
A foam was obtained by adding 15 parts of straight asphalt (penetration 80-100) and changing the amount of catalyst to an appropriate level. The obtained foam has a density of 0.0582g/
cm ³ , air permeability 2.0cc/cm ² /sec, 75% compression, water pressure 10
When a water leakage test was conducted at 15cm and 15cm, no water leakage was observed even after 24 hours. Example 10 Foams with different air permeability were obtained by adjusting the amount of catalyst and crushing the obtained foams according to the formulation of Example 4, and their waterproof properties were measured. Table 5 shows the results.
Shown below.

[Table] As a result, the waterproofness of the foam is approximately
It can be seen that it is good below 100 c.c./cm ² /sec and deteriorates above that. (Effects) As described above, the sealing material according to the present invention has the following effects because even if it is a highly air permeable foam, there is little decrease in waterproofness. 1 When using the sealing material according to the present invention as a backup material for construction, the liquid sealing material that is the primary sealing material has good filling properties and is difficult to form pinholes or voids, and there is no risk of water leakage due to insufficient filling. . 2 Even if the sealing material according to the present invention is used under higher compression, it hardly protrudes from the joints. For example, when a low air permeability sealing material with an air permeability of 0.1 cc/cm ² /sec is compressed by 90%, the protrusion will be about 20% or more of the material width. On the other hand, in the case of the sealing material according to the present invention (for example, about 30 c.c./cm ² sec), the protrusion is about 2 to 5%. This is an advantage for applications where appearance is important.

[Brief explanation of drawings]

The drawings are explanatory diagrams of the waterproof test, and FIG. 1 is a plan view of the test sample, and FIG. 2 is a perspective view of the test sample. 1: Test sample, 2, 3: Acrylic resin plate, 4:
Spencer, 5: Water injection pipe.

Claims (1)

[Claims] 1 Polyol, polyisocyanate (NCO/
OH=0.9~1.3) in the presence of a foam stabilizer and a foaming agent, and the air permeability of 10mm thickness is 100c.c./cm ² /sec.
The following method for producing an open-cell polyurethane foam sealant, characterized in that an organosilicon compound based on a polydialkylsiloxane having a primary or secondary amino group is used as the foam stabilizer. or a method for producing a semi-rigid open-cell polyurethane foam sealant.