JP2002097248A - Urethane resin, civil engineering and building material, and curable composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a urethane resin whose compatibility is improved which increases the rate of curing reaction of the urethane modified by a polysufidepolythiol. SOLUTION: The urethane resin which an isocyanateprepolymer, a polysulfidepolythiol, and a cyclic thioetheramine having a designated structure copolymerize at least is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a urethane resin and a curable composition.

[0002]

2. Description of the Related Art The urethane resin referred to here is one in which an isocyanate group is contained as a polymerizable reactive group in a prepolymer or the like, and may contain other polymerized units. Various urethane resins are used depending on the application. In particular, polyurethanes have many uses and are often used.

[0003] Polyurethane is obtained by the reaction of an isocyanate and a compound having an active hydrogen (curing agent). Even if the same isocyanate is used, various types are obtained depending on the type of the curing agent.

[0004]

It is known that isocyanate causes poor curing when water is present, and it has been considered that the isocyanate cannot be usually applied to a surface or a place where water is present. However, in practice, there is naturally a desire to apply the coating even on such a surface or place. For example, in the case of waterproofing work on a rooftop or various floors, the fact that coating can be performed only after the surface to be coated is completely dried significantly delays the construction period.

[0005] To overcome these disadvantages, the present inventors have recalled the introduction of polysulfide polythiols into polymers. When this polysulfide polythiol was introduced, poor curing did not occur even in the presence of moisture, and both curability and adhesiveness were good. But,
In the two-component system of the urethane prepolymer and the polysulfide polythiol, the polysulfide polythiol works as a curing agent, but the reaction speed is low and the practicality is poor.
In addition, this two-component system had a problem in compatibility with no solvent and was difficult to use.

Therefore, it is conceivable to improve the above two-component system by using a general urethane curing agent. However, since the curing agent mainly contains a chlorine atom, there is a problem of environmental pollution. there were. Further, the three-component system with polysulfide polythiol also has a disadvantage that the curing speed is slow.

Further, the polysulfide polythiol has poor compatibility with isocyanates, and improvement in this respect has been demanded.

[0008]

In view of the above situation, the present inventor has completed the urethane resin of the present invention as a result of intensive studies, and is characterized by at least an isocyanate prepolymer and a polysulfide. The point is that polythiol and a cyclic thioetheramine having a structure represented by the following chemical formula I are copolymerized. [However, 0 ≦ x ≦ 3, 1 ≦ m ≦ 3, 1 <n ≦ 3. R ¹ and R ² are a methyl group, an ethyl group or a propyl group. ]

The isocyanate prepolymer is formed by the reaction of a monomer having an NCO group at a terminal with a polyol or the like, and is formed of MDI (diphenylmethane-
4,4'-diisocyanate) prepolymer and TDI
(Tolylene diisocyanate) prepolymer and other isocyanate prepolymers can be used.

[0010] The polysulfide polythiol referred to herein is one containing one or more units containing S and having an SH group at a terminal. More specifically,
The groups ^{_{-X- (R 3 -S a) b}} -R 4 -Y- ( polysulfide linkage) is one contained in the main chain or side chain. Here, R ³ and R ⁴ are divalent methylene groups (—C
H ₂ —), a divalent dimethyl ether group (—CH ₂ OCH
_2- ) divalent isopropanol group (-CH ₂ CH (O
H) CH ₂ —), divalent ethanol group (—CH ₂ CH)
(OH) -), _{also, (- CH 2 CH 2 OCH} 2 OCH
₂ CH ₂ —), (—CH ₂ CH ₂ O—), etc., which may be one or more or a combination thereof.
R ³ and R ⁴ may be the same or different. X and Y is a group selected -SH, -OH, from -NH _2. a is an integer of 0 to 5 for each repeating unit;
Is an integer of 1 to 50. However, when a is 0 for all the repeating units, one of X and Y is a -SH group. a is preferably 1 to 2.5.

The polysulfide polythiol may be itself or may be an isocyanate monomer or prepolymer in which it is contained somewhere in the structure.

Next, the cyclic thioetheramine referred to in the present invention is a compound represented by the formula I, but may be a mixture of the compounds represented by the formula I. Since there may be a mixture, l, m, and n are not necessarily integers. Examples of these include the following compounds. 3,5-
Bis (methylthio) -2,6-diaminotoluene, 3,5
-Bis (methylthio) -2,4-diaminotoluene and the like.

These cyclic thioetheramine compounds are low-viscosity liquids at room temperature and have low volatility. This cyclic thioetheramine reacts with the isocyanate. That is, it becomes a urethane curing agent. When a three-component system comprising the isocyanate compound and the polysulfide polythiol of the present invention is used, the curing speed can be increased and can be controlled appropriately. Moreover, since it is non-toxic, it is also environmentally friendly. If necessary, other curing agents may be used in addition to the thioetheramine compound. A two-component system of an isocyanate compound and a thioetheramine compound tends to cure too quickly.

The mixing ratio of the three components of isocyanate, polysulfide polythiol and cyclic thioetheramine varies depending on the required curing speed, hardness and strength of the cured product. Assuming that the isocyanate is 100 parts by weight, the polysulfide polythiol is 5 to 900 parts (assuming a molecular weight of about 1,000 to 7,500) and the cyclic thioetheramine is about 5 to 50 parts.

If the amount of the polysulfide polythiol is too small, the inhibition of curing by water or the like increases, and if the amount is too large, there is a problem in strength. If the amount of the cyclic thioetheramine is smaller than the above, the effect peculiar to the curing speed or the like is not exerted. Although the polymerization mechanism of these three components is not clear, it is considered that all are copolymerized. Since the cyclic thioetheramine has S in the molecule, it is considered that the cyclic thioetheramine also has an effect of enhancing the compatibility of the composition.

The urethane resin of the present invention is a cured product of the above mixture, and is a mixture of an isocyanate prepolymer and another liquid.
Use in liquid or three-part systems. The use, place and method of use of this resin are also free. Of course, a solvent may be used. Colorants, weathering agents, antioxidants, pigments, aggregates, etc. may be added, or a hydrophilic agent (surfactant, PVA, etc.) or a hydrophobizing agent (organic silane compound, etc.) may be added or copolymerized. . Anything may be mixed or added without departing from the spirit of the present invention.

The polysulfide-modified urethane resin produced by the present invention contains sulfur and nitrogen and is superior in mechanical and physicochemical properties as compared with a conventional urethane resin containing no polysulfide chain. Other similar resins and urethane resins can be analyzed and identified by elemental analysis, pyrolysis gas chromatography, X-ray microanalysis, infrared absorption spectrum and the like.

Since the urethane resin of the present invention contains polysulfide polythiol and cyclic thioetheramine as essential components as a curing agent component, it is compared with a conventional urethane resin using a curing agent having a terminal hydroxyl group or an amino group. Has excellent physical properties. That is, in addition to physicochemical properties such as adhesiveness (wet surface), water resistance and chemical resistance, mechanical properties such as tensile strength and elongation, shear adhesive strength, and tear strength are exemplified. The resin of the present invention is considered to be widely applicable to conventional urethane resin applications due to its excellent physical properties. However, even if water is present on the surface to be coated, it is unlikely to cause poor curing or poor adhesion, has the advantage of good water resistance and is hardly foamed.
It can be widely applied to civil engineering and building materials that cause various problems due to rainy weather, wetness of water, wetness, seepage of water, submergence, and the like. Typical examples used outdoors include road pavement, marine, coastal, river, lake, and dam related applications. For indoor and underground, painted floor,
Rooftop waterproofing, sewerage, water supply, tunnels, etc. As it can be applied to ready-mixed concrete, it can be used in the production or construction of interlocking blocks (particularly rubber chip aggregates), sidewalk boards, concrete fume pipes, seawall blocks, retaining walls, sabo dams, and the like. Also, it can be applied to uncured concrete surface similarly on concrete pavement, concrete floor, and rooftop waterproofing. It is also suitable as a building exterior material. In such a case, the surface to be applied is a cement-based solidifying material (concrete or the like), and there is an advantage of shortening the construction period such that the application can be performed at a time when the surface is not yet completely cured.

Still another embodiment of the present invention is a mixture before curing. It contains at least the three components of the cyclic thioetheramine described in Formula I above, polysulfide polythiol, and isocyanate prepolymer (which may be modified with polysulfide polythiol).

[0020]

Next, the present invention will be described in more detail with reference to examples. Example 1 of the mixture before curing of the resin of the present invention Components of the mixture Urethane prepolymer (NCO content 9% by weight) 100 parts by weight Polysulfide polythiol 20 parts by weight Cyclic thioetheramine 10 parts by weight Here, TDI prepolymer was used as the urethane prepolymer. As the polysulfide polythiol, "Thiokol LP-3" manufactured by Toray Thiokol Co., Ltd. was used. As the cyclic thioetheramine, 3,5
-Bis (methylthio) -2,6-diaminotoluene, 3,
A mixture of 5-bis (methylthio) -2,4-diaminotoluene (which may also contain other by-products with different side chain positions) was used.

The compatibility and film formability of this mixture were greatly improved as compared with the case where no cyclic thioetheramine was used.

After adding 20 parts of an inorganic pigment to this resin solution, it was applied to the concrete surface. The inorganic pigment is obtained by mixing a coloring pigment with a fine extender pigment. The inorganic pigment is first used as a mixture of thiochol LP-3 and a cyclic thioetheramine, and then mixed with a urethane prepolymer. At this time, the concrete has been cast for about 8 hours, and the surface is still in a state of high moisture content (uncured). The applied amount was 250 g per m ² (as the amount of resin). The curing of the resin after mixing the main agent / curing agent and coating is performed with a gelation time of 30 minutes (25 minutes).
° C) and found to cure rapidly. On the other hand, when the cyclic thioetheramine as the curing agent was replaced with polysulfide polythiol having an equivalent amine amount, the gelation time required was 20 hours or more. The cured coating of the composition of Example 1 showed good adhesion to concrete. The Kenken-type adhesive strength was 13.3 kg / cm ² . No foaming was seen at the concrete / urethane interface. The resin (3 components) of Example 1 was mixed and cured to a thickness of 2 m.
m was prepared and physical properties were measured. As a comparative example, a commercial product (Company A, for floor) was similarly adjusted, and physical properties were measured. Table 1 shows the results.

[0023] As can be seen from Table 1, the sample of Example 1 was at 20 ° C.
After one week, the hardness and the tear strength show higher values than the commercial product (Company A), but after salt spraying, show higher values with a larger difference. The same applies to the tensile strength and elongation, but Example 1 shows a value exceeding 300 kg / cm ² even at an elongation of 360% due to the salt spray treatment. This value is specific.

[0024]

The present invention described above has the following effects. (1) Since the resin of the present invention contains polysulfide polythiol, the presence of a small amount of water hardly inhibits curing and adhesion. (2) Cyclic thioetheramine is environmentally friendly because it is less toxic than conventional curing agents. (3) The cyclic thioetheramine has a high curing speed even as a curing agent, and the speed can be easily adjusted. (4) Compatibility with polysulfide polythiol is better than other curing agents, thereby improving film forming characteristics and speeding up curing.

 ──────────────────────────────────────────────────続 き Continued on the front page (71) Applicant 592189376 Osada Giken Co., Ltd. 9-17, Higashitakatsu-cho, Tennoji-ku, Osaka-shi, Osaka (72) Inventor Tadami Kamaishi 1-1-1, Sonoyama, Otsu-shi, Shiga Toray Co., Ltd. (72) Inventor Toshihiro Maekawa 2-3-7, 18-Jojo, Yodogawa-ku, Osaka-shi Inside the Osaka Plant of Chugai Shoko Co., Ltd. (72) Inventor Kiyoki Ishii 1-81-1, Mihama, Urayasu-shi, Chiba No. Torayville Toraythio Co., Ltd. (72) Inventor Hideharu Nagata 9-17, Higashitakatsu-cho, Tennoji-ku, Osaka City F-term (reference) 4J034 CA14 CB02 CC12 CC61 CD08 DB03 DC50 DD03 DN03 JA01 JA42 RA08

Claims (6)

[Claims] 1. An isocyanate prepolymer, a polysulfide polythiol, and a compound represented by the following formula I:
A urethane resin characterized by being copolymerized with a cyclic thioetheramine having a structure represented by the following formula: [However, 0 ≦ x ≦ 3, 1 ≦ m ≦ 3, 1 <n ≦ 3. R ¹ and R ² are a methyl group, an ethyl group or a propyl group. ] 2. The urethane resin according to claim 1, wherein the isocyanate prepolymer is modified with polysulfide polythiol, and the curing agent is cyclic thioetheramine or cyclic thioetheramine and polysulfide polythiol. 3. A civil engineering / building material comprising the urethane resin according to claim 1 as an essential component. 4. A mixture obtained by further mixing an aggregate.
Civil engineering and building materials as described. 5. A curable composition comprising at least an isocyanate prepolymer modified with an isocyanate prepolymer and / or a polysulfide polythiol, a polysulfide polythiol, and a cyclic thioetheramine having a structure represented by the following chemical formula I. . [However, 0 ≦ x ≦ 3, 1 ≦ m ≦ 3, 1 <n ≦ 3. R ¹ and R ² are a methyl group, an ethyl group or a propyl group. ] 6. The curable composition according to claim 5, further comprising an aggregate.