JPS6112780A - Urethane mastic composition and sealing method of building joint using same - Google Patents

Abstract

PURPOSE:The titled composition, which is a desired viscous material consisting of a specific active-isocyanate group-containing urethane prepolymer and an excess amount of a specific polyol component, suitable for sealing compounds of building joints without deteriorating finishing paints. CONSTITUTION:A composition which is a two-pack type mastic composition, consisting of (A) a urethane prepolymer having 2-4 isocyanate groups in one molecule and 2.0-7.0wt% isocyanate group content and (B) a polyoxyalkylene polyol having >=2 hydroxyl groups in one molecule at >=1.0:1 molar ratio between the isocyanate groups in the component (A) and hydroxyl groups in the component (B), and obtained by incorporating a filler with the components (A) and/or component (B).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a two-component urethane mastic composition and a sealing method for building joints using the same.

Prior Art and Problems to be Solved Usually, various sealing materials and caulking materials are injected and filled into the joints of buildings for the purpose of waterproofing. Special number: Urethane resin, polysulfide, silicone and modified silicone, acrylic resin, as sealing materials.
Butylcomb is desirable as a joint waterproofing material because of its rubber elasticity after curing and drying, and its durability against expansion/contraction and vibration of building joints, but due to its high cost, it is mainly used in mid-to-high-rise buildings. On the other hand, oil-based caulking materials, which fall under the category of caulking materials, have a poor ability to respond to external stress due to the above-mentioned expansion/contraction or vibration, and also discolor the finishing paint applied to the surface from yellow to brown, which can cause problems in the appearance of buildings. Makeup” Second undesirable. Therefore, there is a growing demand for the practical use of mastic sealing materials that are similar to activated caulking materials and are inexpensive, have some ability to follow the expansion and contraction of architectural joints, or vibrations, and do not discolor or stain surface finishing paints. The mastic composition used here is a composition consisting of liquid resin or liquid rubber, fillers, other additives, etc. with a volatile component of 5% or less (by weight, the same applies hereinafter), and remains in an incompletely cured state even after curing and drying. A viscous substance.

In order to satisfy the above-mentioned needs, the present inventors conducted intensive studies on various materials and found a urethane mastic composition consisting of a specific active isonoatom group-containing urethane prepolymer and an excess amount of a specific polyol component. The inventors have discovered that when used as a sealant, it becomes a desired viscous substance and does not discolor or stain the finishing paint applied to its surface, leading to the completion of the present invention.

That is, the present invention has (1) 2 to 4 active isocyanate groups in one molecule, and isocyanate groups (hereinafter referred to as NGO
content 2.0 to 7. A two-part urethane mastic composition comprising a urethane prepolymer ofofo and a polyoxyalkylene ether polyol having two or more hydroxyl groups in one molecule, wherein the polyoxyalkylene ether is The molar ratio of hydroxyl groups in the polyol is 1.0 or more,
and (2) a two-component urethane mastic composition characterized in that a filler is blended into at least one of the urethane prepolymer and polyoxyalkylene ether polyol; The present invention provides a construction method for sealing architectural joints, which is characterized by filling and coating.

The urethane prepolymer used in the present invention is obtained by reacting an excess amount of an organic diisocyanate compound with a polyol having two or more hydroxyl groups in one molecule, and contains two to four active NGOs in one molecule. NGO content with 2
．． 0 to 7.0fo. NGO content is 2.0
If it is less than %, the viscosity of the prepolymer will be high, workability will be poor, weather resistance will be poor, and the cost of the sealing material of the present invention will be high, which poses practical problems. Also, 70
%, the increase in urethane bonds tends to cause yellowing due to heat or light, which poses a problem in terms of design.

Examples of the above-mentioned organic diisocyanate compounds include trilene diisocyanate, diphenylmethane-4,4'
- Aromatic diisocyanates such as phthalene diisocyanate, 1,5-naphthalene diisocyanate, -t, and xylylene diisocyanate; Diisocyanates are preferred.

Examples of the above-mentioned polyols include polyoxyalkylene ether polyols, polyester polyols,
Examples include butadiene polyols, acrylic polyols, castor oil derivatives, tall oil derivatives, etc. In particular, polyoxyalkylene ether polyols, diols with a hydroxyl equivalent of 200 to 1,500 or diols with a hydroxyl equivalent of 500 to 1,500.
Preferably, each of the 2500 triols is used alone or in combination.

The reaction between the organic diisocyanate compound and the polyol may be carried out according to conventional conditions, for example, by mixing the organic diisocyanate compound with a previously dehydrated polyol,
What is necessary is just to make it react under heating of 70-110 degreeC for 4-8 hours. In addition, a catalyst such as dibutyltin dilaurate, dibutyltin maleate, lead octenoate, or lead octenoate may be used in the reaction. The reaction ratio of both components is usually 1 mole of hydroxyl group of polyol to NCO of organic diisocyanate.
The molar ratio of
React until the concentration is ~5.0%. In addition, by using the above diol and triol in combination, the N of urethane prepolymer
Preferably, the number of CO functional groups is 2.3 to 3.0.

The polyoxyalkylene ether polyol used in the present invention refers to a random or block copolymer polyoxyalkylene ether polyol or polyol obtained by ring-opening polymerization of a polyhydric alcohol and an alkylene oxide (ethylene oxide, propylene oxide, etc.) or tetrahydropran. Quintetramenalene glycol. Particularly preferred are polypropylene-ethylene ether polyols, and diols or triols having a hydroxyl group of -1200 to 2500. Also, the molecular weight is 400
~4000 diol or molecular weight 1500-7000
triols are preferred.

The two-component urethane mastic composition according to the present invention consists of a main ingredient made of the above-mentioned urethane prepolymer and a curing agent made of polyoxyalkylene ether polyol, and in addition, at least one of the main ingredient and the curing agent is filled. It is a two-component mixture type in which the base agent and curing agent are mixed before use. In the two-component mixing ratio, the molar ratio of the hydroxyl groups of the polyoxyalkylene ether polyol to 1 mole of NC0 of the urethane prepolymer is 1.
．． The number should be in the range of 0 or more, preferably 1.02 to 30. If the polyoxyalkylene ether polyol is used in an excessive amount, it may be unreacted or plasticized, resulting in a mastic-like viscous material. It becomes 9/♂ or less and 1. ■The consistency of the urethane prepolymer is 10 to 100° as measured by the penetration of a penetrometer according to 15K2530, and in particular, a diol with a molecular weight of 3000 to 5000 is used as the polyoxyalkylene ether polyol, and the NC01 of the urethane prepolymer is It is preferable that the molar ratio of hydroxyl groups to moles is in excess of 1.02 to 2.5. The ratio of the base resin to the curing agent (including the filler and additives described below if they are included on both sides) is usually designed so that the weight ratio of the curing agent is 300 to 500 parts per 100 parts of the base resin. This makes mixing work easier during use, reduces mixing errors, and is economically desirable.

The filler used in the present invention can be blended into either or both of the base agent and the curing agent as described above, but when blended with the base agent, it is necessary to dry the water that reacts with NGO contained in the filler. Therefore, its management is troublesome, and the manufacturing cost is high.
Drying is necessary (desirable). Specific examples of such fillers include precipitated calcium carbonate, slightly surface-treated calcium carbonate, clay, talc, silica, carphone, and barium sulfate. It is preferable to use fibrous pulp fibers, polyolefin fibers, asbestos, etc. in combination with fibrous pulp fibers, polyolefin fibers, asbestos, etc., since this can suppress the expansion and contraction of the urethane mastic composition of the present invention, cracking, cutting, etc. due to external stress due to vibration.Polyoxyalkylene ether polyol In a hardening agent containing a filler and a filler,
The blending ratio of the filler is usually 40 to 60fo. In particular, when a fibrous filler is blended in a proportion of 2 to 7%, the surface finish becomes more uniform, and it is also advantageous in terms of the physical properties listed in "2".

In the composition of the present invention, in addition to the above-mentioned essential components, an ultraviolet curable resin and/or a drying oil may be added, preferably in an amount of 5 to 15% based on the curing agent. After the composition of the present invention is injected, filled, or applied to the joints of a building, a thin film is formed on the surface by sunlight, which reduces the adhesion of dust such as dirt and suppresses plastic flow.

Examples of the ultraviolet curable resin include polyester acrylate, polyether acrylate, epoxy acrylate, urethane acrylate, vinyl compound, and unsaturated polyester, with acrylic resins being particularly preferred. The drying oil also contributes to the film formation, since it is oxidized and solidified by oxygen absorption in the air. Specific examples of drying oils include vegetable oils such as J Maniura, tung oil, hemp oil, and walnut oil. When using an ultraviolet curable resin, adding a photopolymerization initiator such as a benzoin compound, an azo compound, a diphenyl disulfide compound, or an organic peroxide at a rate of 1.0% or less will prevent film formation. is preferable because it promotes

Further, in the composition of the present invention, conventional additives such as the catalysts for promoting the urethane reaction, anti-aging agents, pigments, moisture absorbers, adhesion agents, viscosity-adjusting solvents, etc. can also be appropriately incorporated.

The composition of the present invention having the above structure is usually used as a waterproofing material for preventing rainwater from entering through joints of panels, concrete, etc. of buildings such as apartment houses.

The sealing method for building joints according to the present invention is comprised of injecting, filling, and applying the composition of the present invention into joints of buildings. Specifically, the main ingredient and curing agent of the composition of the present invention are mixed in a predetermined ratio, and this is injected, filled, and applied to a predetermined area using a caulking gun.

After application, a rubber spatula is used to make the coating surface uniform, and then regular exterior wall finishing paints, so-called lysine spray paint, and tile spray paint are applied to improve the appearance of the building. Recently, it has been finished by painting with elastic spray paint. In this construction method, the composition of the present invention does not use large amounts of plasticizers (particularly aromatic plasticizers that tend to cause yellowing) that migrate through the finishing paint and separate on the surface, so the finishing To provide a good aesthetic effect without staining or discoloring the paint. Furthermore, unlike conventional oil-based caulking materials, the composition of the present invention is a urethane material, so it provides excellent durability and is considerably cheaper than elastic sealants, so it is advantageous in terms of cost.

Next, the present invention will be explained in more detail with reference to Production Examples, Examples, and Comparative Examples.

Production Examples 1 to 4 (Production of urethane prepolymer) The ingredients in the proportions shown in Table 1 were accurately weighed in a sealed container, heated to 80°C while refluxing nitrogen gas, and reacted for 4 hours to produce urethane prepolymer. Obtain the polymer.

Table 1 Examples 1 to 4 and Comparative Example 1 A urethane mastic composition is prepared by mixing the main ingredient and curing agent in the proportions shown in Table 2. These were evaluated according to the JIS A3751 standard for oil-based caulking materials, and the results are shown in Table 2.

The urethane mastic composition of Sealing Method Examples 1 to 4 or Comparative Example 1 was formed using an aluminum plate,
After injecting, filling, and coating a virtual joint with a depth of 15 m + and a length of 20 cm, smooth it with a rubber spatula to make the surface uniform.
Next, paint the exterior wall white paint (Beta All '3000, manufactured by Sunstar Giken Co., Ltd.).

Evaluation of contamination and discoloration of the painted surface was performed using a Sunshine Weather-Ometer after 200 hours of irradiation, and the results are also listed in Table 2.

Table 2 Note (f)) According to JIS K 2530. Fill a pudding cup with a diameter of 50 mφ and a depth of 30 mm, make the surface uniform, and then leave it outdoors for 3 days before measuring.

0 The skin tension condition was determined by touch using the same sample as in Note ■.

00: Almost no discoloration by visual observation.

×: Discolored to yellow

Claims (1)

[Claims] 1. A urethane prepolymer having 2 to 4 active isocyanate groups in one molecule and having an isocyanate group content of 2.0 to 7.0% by weight, and two or more active isocyanate groups in one molecule. A two-component urethane mastic composition comprising a polyoxyalkylene ether polyol having a hydroxyl group of A two-component urethane mastic composition characterized in that a filler is blended into at least one of the urethane prepolymer and the polyoxyalkylene ether polyol. 2. The composition according to item 1 above, wherein the polyoxyalkylene ether polyol has a hydroxyl equivalent of 200 to 2,500. 3. The first above, wherein the molar ratio of the hydroxyl groups of the polyoxyalkylene ether polyol to 1 mole of isocyanate groups of the urethane prepolymer is in the range of 1.02 to 3.0.
Compositions as described in Section. 4. The composition according to item 1 above, wherein the total amount of the urethane prepolymer and polyoxyalkylene ether polyol in the urethane mastic composition is in the range of 30 to 60% by weight. 5. The composition according to item 1 above, which further contains an ultraviolet curable resin and/or a drying oil. 6. Urethane prepolymer having 2 to 4 active isocyanate groups in one molecule and having an isocyanate group content of 2.0 to 7.0% by weight, and polyoxy having two or more hydroxyl groups in one molecule a two-component urethane mastic composition comprising an alkylene ether polyol, wherein the molar ratio of hydroxyl groups in the polyoxyalkylene ether polyol to 1 mole of isocyanate groups in the urethane prepolymer is 1.0 or more, and A method for sealing building joints, which comprises filling and applying a two-component urethane mastic composition comprising a filler mixed with at least one of a polymer and a polyoxyalkylene ether polyol into the joints of a building. 7. The sealing method according to item 6 above, wherein after filling and applying the two-component urethane mastic composition, the coated surface is leveled uniformly with a spatula, and then a final coat is applied.