JPH10176028A - Room temperature-curing resin composition and sealing material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition useful as a sealing material excellent in anti-tack properties and curing abilities by using a resin having a hydrolyzable silicone group derived from a specific polyisocyanate. SOLUTION: This room temperature-curing resin composition is obtained by the following procedures. A hydrolyzable silicon-containing compound is added in 5-100wt.% based on isocyanate groups to a polyisocyanate obtained by reacting an aliphatic and/or an alicyclic diisocyanate monomer with a polyol having 6,000-30,000 molecular weight and 2-3 average hydroxyl functional groups in an equivalent ratio of isocyanate group/hydroxyl group of 5/1-100/1, and essentially removing the unreacted diisocyanate monomers and a solvent, where the polyisocyanate has such characteristics that contains 0-5wt.% diisocyanate monomer, 0.5-10wt.% isocyanate group, 1,000-30,000mPa.s viscosity at 25 deg.C and 1.1-10 dispersivity (weight average molecular weight/number average molecular weight).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel room-temperature-curable resin composition derived from a polyisocyanate and having a hydrolyzable silicon-containing compound added thereto, and a sealing material using the same.

[0002]

2. Description of the Related Art Polymers having a functional group at the end and exhibiting rubber elasticity after curing are used as sealing materials for construction and automobiles.
Used as an adhesive. In particular, high molecular weight polymers such as polyoxyalkylene polyethers having hydrolyzable silicon as a terminal functional group are widely used because they have excellent physical properties such as adhesion and weather resistance. It is being studied for even higher physical properties.

For example, in Japanese Patent Application Laid-Open No. 5-65400, a photocurable compound is added to improve the surface contamination of a cured product. In JP-A-7-258534 and JP-A-7-300555, a specific silicon compound is added in order to improve tack resistance and the like. The polyoxyalkylene polyether having a hydrolyzable silicon terminal at the terminal used in these compounds is a polyoxyalkylene polyether having an unsaturated group such as a terminal olefin group, an acryloyl group, a methacryloyl group or the like which is directly bonded to a silicon atom. Hydrosilane having a decomposable group is added.

The high molecular weight product obtained by such a method basically has problems in tack resistance, curability and the like. That is, the introduction of the hydrolyzable silicon to the terminal by the method described above has not been completely performed. The reason is that when a double-bonded polyoxyalkylene polyether is synthesized,
This is because the transfer of a heavy bond occurs and a branched unsaturated group such as an isopropenyl group is not formed. Therefore, the addition of the hydrosilane having a hydrolyzable group is hindered by steric hindrance, and the addition to the polyoxyalkylene polyether is not completely performed.

In Japanese Patent Publication No. 46-30711, isocyanate is added to a terminal hydroxyl group of a polyoxyalkylene polyale to form an isocyanate-terminated polyoxyalkylene polyether, and then the active hydrogen-containing hydrolyzable silicon reacts with the isocyanate group. Methods for adding compounds have been proposed. JP-B-46-12154 proposes a method of adding an active hydrogen-containing olefinic unsaturated compound to an isocyanate-terminated polyoxyalkylene polyether and then adding a hydrosilane having a hydrolyzable group. In JP-A-51-73561, an active hydrogen-containing hydrolyzable silicon compound is added to an isocyanate-terminated polyoxyalkylene polyether having a urethane bond.

However, in order to increase the molecular weight of these isocyanate-terminated polyoxyalkylene polyethers, the equivalent ratio between isocyanate groups and hydroxyl groups is set low as a condition for the production. Although the molecular weight of the thus obtained isocyanate-terminated polyoxyalkylene polyether increases, the degree of dispersion of the molecular weight distribution also increases, and the urethane bond concentration increases. as a result,
It had high viscosity and had problems in physical properties after curing.

JP-A-57-164123, WO9
In the specification of 1/15536, an isocyanate group-containing hydrolyzable silicon compound is added to a polyalkylene glycol having a terminal hydroxyl group. This method can reduce the urethane bond concentration as compared to the above method, but when a high molecular weight polyalkylene glycol produced using a potassium hydroxide catalyst or the like is used, the monoalcohol contained therein is an isocyanate group-containing hydrolyzable silicon. Even when it reacts with the compound, it is still monofunctional, and adversely affects the physical properties of the cured resin. In addition, isocyanate group-containing hydrolyzable silicon compounds are expensive and have problems in industrial production.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a room temperature-curable resin composition useful for a sealing material excellent in tack resistance and curability, a bonding agent and the like, and a sealing material containing the same. And

[0009]

Means for Solving the Problems The present inventors have found that the above problems can be solved by using a resin having a hydrolyzable silicon group derived from a specific polyisocyanate. Was. That is, the present invention is as follows. [1] An aliphatic and / or alicyclic diisocyanate monomer and a polyol having a molecular weight of 6,000 to 30,000 and an average number of hydroxyl functional groups of 2 to 3 are mixed at an isocyanate group / hydroxyl equivalent ratio of 5/1 to 100/1. After the reaction, the unreacted diisocyanate monomer and solvent are substantially removed, and the polyisocyanate having the following characteristics (1) to (4) has a polyisocyanate content of 5 to 100
% Of the composition containing a hydrolyzable silicon-containing compound. (1) Diisocyanate monomer concentration; 0 to 5% by weight (2) Isocyanate group concentration; 0.5 to 10% by weight (3) Viscosity at 25 ° C; 1,000 to 30,000 mP
a · s (4) Dispersion degree (weight average molecular weight / number average molecular weight);
1 to 10 [2] The room-temperature-curable resin composition according to the above 1, wherein the polyisocyanate contains an allophanate bond. [3] The room temperature curable resin composition according to the above [1] or [2], wherein the polyol is a propylene oxide adduct polyether polyol. [4] A sealing material containing at least one of the room temperature-curable resin compositions according to the above item 1 or 2 or 3.

Hereinafter, the present invention will be described in detail. The diisocyanate used in the present invention is aliphatic and / or alicyclic. In fields where weather resistance and the like are not particularly required, aromatic isocyanates can also be used. The aliphatic diisocyanate monomer preferably has 4 to 30 carbon atoms, and the alicyclic diisocyanate monomer preferably has 8 to 30 carbon atoms.
1,4-diisocyanate, pentamethylene-1,5-
Diisocyanate, hexamethylene diisocyanate,
2,2,4-trimethyl-hexamethylene-1,6-diisocyanate, lysine diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) -cyclohexane, 4,4′-dicyclohexylmethane diisocyanate, and the like can be given. . Among them, hexamethylene diisocyanate (hereinafter, referred to as HMDI) and isophorone diisocyanate (hereinafter, referred to as IPDI) are preferable from the viewpoint of weather resistance and industrial availability, and they may be used alone or in combination.

The average number of hydroxyl functional groups of the polyol used in the present invention is preferably 2-3. If it is less than 2, the curability is poor,
If it exceeds 3, physical properties of the cured resin are reduced. Polyols include acryl, polyester, polybutadiene, polyether and the like, and polyether polyol is preferable. For the production of polyether polyols, polyhydric alcohols, polyhydric phenols, polyamines, alkanolamines, etc., specifically, for example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol , 1,6-hexanediol, dihydric alcohols such as bisphenol A, glycerin, trihydric alcohols such as trimethylolpropane, and diamines such as ethylenediamine, alone or in mixture, for example, hydroxides such as lithium, sodium, and potassium; Strong base catalysts such as alcoholates and alkylamines, metal porphyrins,
Using a complex metal complex such as a complex metal cyanide complex, a complex of a metal and a chelating agent having a tridentate or higher coordinate, and a zinc hexacyanocobaltate complex, ethylene oxide, propylene oxide, butylene oxide, cyclohexene oxide, styrene oxide Or a mixture of such alkylene oxides alone or in combination.

The preferred alkylene oxide is propylene oxide. The molecular weight of the polyol is 6,000
~ 30,000, more preferably 6,000
~ 20,000, particularly preferably 6,000 ~ 1
5,000. When the molecular weight is less than 6,000, physical properties of the cured resin such as elongation are reduced, and when it is more than 30,000, the curability is deteriorated.

The diisocyanate and the polyol are reacted at an isocyanate / hydroxyl equivalent ratio of 5/1 to 100/1. Preferably it is 10/1 to 100/1. When the equivalent ratio is less than 5/1, the viscosity of the reaction solution increases,
If it exceeds 100/1, the yield decreases, which is not preferable in terms of productivity. In the reaction, a solvent may be used, but in that case, a solvent inert to the isocyanate should be used.

[0014] The reaction temperature is preferably from 60 to 200 ° C, more preferably from 120 to 180 ° C. Reaction temperature 60
If the temperature is lower than ℃, the reaction rate is low and the productivity is poor, and it is difficult to generate allophanate bonds. If the temperature is higher than 200 ° C, side reactions such as coloring may occur. During the reaction,
A catalyst can also be used. As the catalyst, those having basicity are generally preferable. For example, quaternary amine compounds such as tetraalkylammonium hydroxide and organic weak acid salts such as acetic acid and capric acid, for example, trioctylamine, 1,4-diazabicyclo Tertiary amine compounds such as (2,2,2) octane, 1,8-diazabicyclo (5,4,0) undecene-7 and 1,5-diazabicyclo (4,3,0) nonene-5, for example, A catalyst that promotes the allophanation reaction, such as a metal salt of acetylacetone such as zinc, or a weak organic salt of metal such as zinc, tin, lead, or iron is also effective.

The catalyst concentration is usually selected from the range of 10 ppm to 1.0% based on the isocyanate compound.
It is preferable that at least a part of the urethane bond present in the reaction solution is converted to an allophanate bond. Allophanate bond / (urethane bond + allophanate bond) is 10% or more, preferably 20% or more. The value is 1
If it is less than 0%, good physical properties such as curability may not be obtained.

After the reaction, unreacted diisocyanate and solvent are removed by a method such as thin film distillation or extraction. The concentration of the diisocyanate monomer contained in the obtained polyisocyanate is 0 to 5% by weight or less, preferably 0 to 2% by weight. Further, the degree of dispersion calculated from the weight average molecular weight / number average molecular weight of molecular weight 700 or more is 1.1 to 10,
Preferably it is 1.1-5. The isocyanate group concentration is 0.5 to 10% by weight, preferably 0.5 to 5% by weight. If it is less than 0.5% by weight, the curability, tack resistance, storage stability, mechanical properties of the cured resin are poor,
If the content exceeds 10% by weight, foaming occurs during curing, and the cured resin has an adverse effect on elongation. The viscosity at 25 ° C. is 1,000 to 30,000 mPa · s.

The yield calculated using the charged amounts of the diisocyanate monomer and the polyol as the denominator and the obtained polyisocyanate as a molecule is about 20 to 70% by weight. Thus, the polyisocyanate in which the diisocyanate monomer and the specific polyol are reacted with a high equivalent ratio of isocyanate / hydroxyl group, and the polyisocyanate from which the unreacted diisocyanate monomer is removed has a low equivalent ratio of isocyanate group / hydroxyl group, which has been performed so far. In addition, it was surprising that a remarkable difference in physical properties was exhibited as compared with polyisocyanate from which unreacted diisocyanate was not removed.

The polyisocyanate obtained by reacting at a high equivalent ratio of isocyanate group / hydroxyl group is different from the polyisocyanate obtained by reacting at a low equivalent ratio in that, for example, the monool contained in the polyol is a diisocyanate. Naturally, the amount of inactive low molecular compounds produced by reaction addition to both ends of the polyisocyanate is significantly reduced, and the monool has an isocyanate group in the molecule. There is almost no bleed-out.

The hydrolyzable silicon-containing compound used in the present invention is preferably a compound shown below containing an active hydrogen capable of reacting with an isocyanate group.

[0020]

Embedded image

The hydrolyzable group of the hydrolyzable silicon-containing compound includes an alkoxysilyl group, an acyloxysilyl group,
Examples include an aminoxysilyl group, an acetoxysilyl group, a phenoxysilyl group, a thioalkoxysilyl group, and a ketoximesilyl group. Examples of the specific compounds are shown below. Compounds wherein Z is a primary amine include, for example, 3-
Aminopropylmethoxydimethylsilane, 3-aminopropyldimethoxymethylsilane, 3-aminopropyltrimethoxysilane, 3-aminopropylethoxydimethylsilane, 3-aminopropyldiethoxymethylsilane, 3-aminopropyltriethoxysilane, 3-amino Propylmethoxydiethylsilane, 3-aminopropyldimethoxyethylsilane, 3-aminopropylethoxydiethylsilane, 3-aminopropyldiethoxyethylsilane, 3-aminopropyldiphenoxymethylsilane, N- (triethoxysilylpropyl) urea, 2 −
(2-aminoethylthioethyl) diethoxymethylsilane, 2- (2-aminoethylthioethyl) triethoxysilane, N, N-bis [3-methyldimethoxysilyl)
Propyl] ethylenediamine, N, N-bis [3- (trimethoxysilyl) propyl] ethylenediamine,
Compounds that are secondary amines include, for example, N-methylaminopropyldimethoxymethylsilane, N-ethylaminopropyldimethoxymethylsilane, dimethoxymethyl-3-piperazinopropylsilane, 3-piperazinopropyltrimethoxy For compounds having a hydroxyl group, such as silane, 3-benzylaminopropyltrimethoxysilane, N, N-bis [(methyldimethoxysilyl) propyl] amine, N-phenylaminomethyltrimethoxysilane, and N-phenylaminopropyltrimethoxysilane Examples of the compound having a mercapto group such as 3-hydroxypropyltrimethoxysilane include 3-mercaptopropyldimethoxymethylsilane and 3-mercaptopropyltrimethoxysilane.

By reacting the polyisocyanate with a hydrolyzable silicon-containing compound having active hydrogen,
The room temperature curable resin composition of the present invention is obtained. In the above reaction, the equivalent ratio of active hydrogen to isocyanate groups of polyisocyanate (active hydrogen / isocyanate group) is 5 to 1
It is preferably 10%, more preferably 50 to 105%. Excess active hydrogen in excess of 100% is used as a means to produce a resin composition in which all isocyanate groups have reacted with active hydrogen.

In the reaction, a solvent and a reaction accelerator may be used. As the solvent, a solvent which is inert to the isocyanate group should be used, but can be used if the reactivity of the isocyanate group is lower than the active hydrogen. Examples of the reaction accelerator include organic metal compounds such as dibutyltin dilaurate and basic compounds such as amines. The reaction temperature and reaction time are determined according to the reactivity between the isocyanate group and active hydrogen.

The reaction between the isocyanate group and the active hydrogen is completed, and the room temperature curable resin composition of the present invention is obtained. The room temperature curable resin composition of the present invention, a solvent, a plasticizer, a filler, a thixotropic agent, a curing accelerator, an ultraviolet absorber, a dye, a pigment,
It contains a flame retardant and becomes a sealing material.

Examples of the solvent include aromatic hydrocarbons such as toluene and xylene, aliphatic hydrocarbons such as hexane, peptane and octane, and petroleum solvents such as gasoline and kerosene. As a plasticizer, dibutyl phthalate, phthalic acid derivatives such as dioctyl phthalate, benzoic acid, trimellitic acid, pyromellitic acid, adipic acid, sebacic acid, fumaric acid, maleic acid, itaconic acid, derivatives such as citric acid, polyester, Examples include polyether and epoxy type.

As the filler, silicic acid derivatives, talc,
Examples include metal powder, calcium carbonate, clay, and carbon black. Examples of the thixotropic agent include bentone, silicic anhydride, silicic acid derivatives, urea derivatives and the like. As a curing accelerator, organic tin compounds such as dibutyltin dilaurate and dioctyltin dilaurate, organic zinc compounds such as zinc octylate, triethyleneamine, triethylenediamine, laurylamine, morpholine, diazabicyclocycloundecene, and diazatin Examples thereof include amine compounds such as bicyclooctane and aminosilane compounds such as 3-aminopropyltrimethoxysilane, and these may be used in combination.

If necessary, for example, a bisphenol type epoxy resin may be mixed. The room-temperature-curable resin composition of the present invention can be used as a sealing material, an adhesive, a sealing material, a potting material, and the like, for buildings, automobiles, electric appliances, and the like.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples. In addition, the measuring method etc. are as follows. (Measurement of number average molecular weight and weight average molecular weight) The number average molecular weight is a number average molecular weight based on polystyrene measured by gel permeation chromatography (hereinafter, referred to as GPC) using the following apparatus. Apparatus: Tosoh Corporation HLC-8120GPC Column: Tosoh Corporation TSKgel SuperH 1000 × 1 Tosoh Corporation TSKgel SuperH 2000 × 1 Tosoh Corporation TSKgel SuperH 3000 × 1 Carrier: Tetrahydrofuran Detection method: Differential Refractometer (Quantification of diisocyanate monomer concentration) It was determined from a calibration curve of diisocyanate monomer prepared by using the GPC. (Viscosity) The viscosity at a temperature of 25 ° C. was measured by an Emira type viscometer. (Allophanate bond concentration) FT-NMR of JEOL
Using "FX90Q", acetone-d6 was used as a solvent, and as a result of H-NMR measurement, the peak integrated value of allophanate bond and urethane bond was expressed as allophanate bond / (allophanate bond + urethane bond).
0% or more was A, 10% or more and less than 20% was B, and less than 10% was C. (Measurement of breaking strength and breaking elongation) Polyisocyanate was poured into a mold so as to have a thickness of 1 mm, and the temperature was 20 ° C and the humidity was 65.
RH%, after leaving for 3 weeks, at 20 ° C, pulling speed 60m
The breaking strength at m / min and the breaking elongation were measured.

[0029]

[Production Example 1] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing pipe, and a dropping funnel was set to a nitrogen atmosphere, 300 parts of HMDI, and a divalent polyether polyol (trade name of Asahi Glass) 365 parts of Preminol 4010 (number average molecular weight 10,000) (equivalent ratio of isocyanate group / hydroxyl group 50/1) was charged, and the temperature inside the reactor was maintained at 160 ° C. for 3 hours with stirring in a nitrogen atmosphere.
Reduce the temperature of the reaction solution and use a thin-film evaporator to remove unreacted HMD.
I was removed. Table 1 shows the number average molecular weight, allophanate concentration, isocyanate concentration, viscosity, dispersity, and diisocyanate monomer concentration of the obtained polyisocyanate.

[0030]

Production Example 2 The same procedure as in Example 1 was carried out except that the polyols shown in Table 1 were used. Table 1 shows the results.

[0031]

Production Comparative Examples 1 to 3 The same procedures as in Example 1 were carried out except that the polyols shown in Table 1 were used. Table 1 shows the results.

[0032]

Example 1 A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel was set to a nitrogen atmosphere, and 100 parts of the polyisocyanate obtained in Production Example 1 was charged. 5.0 parts of aminopropyldiethoxysilane (equivalent ratio of isocyanate group / amine group is 1 /
1.1) was added dropwise. No isocyanate group characteristic absorption of this polymer was detected by infrared spectrum measurement. Further, dibutyltin dilaurate is added to the resin in an amount of 3%.
% By weight and mixed.

Table 2 shows the measurement results of the breaking strength and the breaking elongation.

[0034]

Example 2, Comparative Examples 1 to 3 The same procedure as in Example 1 was carried out except that the polyisocyanate and 3-aminopropyldiethoxysilane shown in Table 2 were used. Table 2 shows the results of the breaking strength and the breaking elongation.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

The novel room-temperature-curable resin composition having a hydrolyzable silicon group of the present invention is useful as a sealing material for buildings and automobiles, and has a low viscosity and a low surface tack.
Excellent physical properties such as stain resistance are obtained.

Claims (4)

[Claims] 1. An aliphatic and / or alicyclic diisocyanate monomer and a polyol having a molecular weight of 6,000 to 30,000 and an average number of hydroxyl functional groups of 2 to 3 are mixed at an isocyanate group / hydroxyl equivalent ratio of 5/1 to 100. / 1 after the reaction, the unreacted diisocyanate monomer and the solvent are substantially removed, and the polyisocyanate having the following characteristics (1) to (4) has 5 isocyanate groups.
A room-temperature curable resin composition in which a hydrolyzable silicon-containing compound is added to about 100%. (1) Diisocyanate monomer concentration; 0 to 5% by weight (2) Isocyanate group concentration; 0.5 to 10% by weight (3) Viscosity at 25 ° C; 1,000 to 30,000 mP
a · s (4) Dispersion degree (weight average molecular weight / number average molecular weight);
1 to 10 2. The room temperature curable resin composition according to claim 1, wherein the polyisocyanate contains an allophanate bond. 3. The room temperature curable resin composition according to claim 1, wherein the polyol is a propylene oxide adduct polyether polyol. 4. A sealing material containing at least one of the room temperature-curable resin compositions according to claim 1.