JPH02160890A - Urethane sealant composition - Google Patents

Abstract

PURPOSE:To obtain the title composition free from bleeding of a plasticizer and excellent in adhesiveness, elasticity, low-temperature resistance, stain resis tance, etc., by incorporating a polyester plasticizer into a urethane prepolymer. CONSTITUTION:A urethane prepolymer (e.g. a urethane prepolymer based on polypropylene glycol) is mixed with a polyester plasticizer obtained by reacting a polyether polyol preferably of the formula (wherein R is 2-4C alkylene; n is 1 to 20) (e.g. diethylene glycol) with a dibasic acid (e.g. adipic acid).

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to urethane sealant compositions. More specifically, the present invention relates to a urethane sealant composition with excellent migration resistance.

It is essential to use a plasticizer in combination with a urethane sealant in order to give it flexibility, and the urethane sealant obtained by blending a plasticizer with a urethane prepolymer has the same properties as its properties, namely good elasticity, adhesion, and cold resistance. It is widely used in civil engineering and construction as a joint material, adhesive, caulking agent, etc. due to its properties such as hardness, wear resistance, and chemical resistance. However, when conventional urethane sealants are used for a long time, the plasticizer bleeds out, and although various efforts have been made to solve this problem, no satisfactory solution has yet been found. do not have.

After curing, urethane sealants tend to cause the so-called bleed phenomenon in which the mixed plasticizer dissolves onto the coating surface over time, which may prevent the above-mentioned excellent performance from being maintained over a long period of time or cause stains on the sealing area. However, there are disadvantages such as adhesion of particles, and a sufficient solution has not yet been found.

However, the inventors of the present invention have conducted extensive research to solve the above-mentioned problems. In other words, the present invention provides a ureta sealant that does not cause any plasticizer bleed phenomenon and permanently maintains the excellent properties inherent in ureta sealants such as adhesiveness, elasticity, cold resistance, and stain resistance. The purpose is to provide.

The urethane sealant composition of the present invention is a composition in which a polyester plasticizer is blended with a urethane prepolymer.

The urethane prepolymer used in the present invention has 2
It is a polymer obtained by reacting polyols, polyether polyols, and polyester polyols having two or more hydroxyl groups with polyisocyanates having two or more incyanate groups, and is a polymer obtained by reacting polyols, polyether polyols, and polyester polyols having two or more hydroxyl groups with a polyisocyanate having two or more incyanate groups.
, is a prepolymer with CO base. Furthermore, isocyanate group-containing prepolymers containing about 1 to 6% of terminal NCO groups, which are obtained by reacting polyols, polyether polyols, and polyester polyols with organic polyisocyanates, are preferred.

This prepolymer may be further added with a crosslinking agent, but even if no crosslinking agent is added, the reaction proceeds with moisture in the air and becomes a polymer.

Polyols include polyethylene glycol and poly10.
Examples include pyrene glycol. .

Ethylene glycol as polyether polyol,
diethylene glycol, triethylene glycol,
1,2-propylene glycol, dipropylene glycol, trimethylene glycol, 14 or 1,3-
Butylene glycol, tetramethylene glycol, neopentyl glycol, 22-diethyl-1,3-propanediol, 2-n-butyl-2-ethyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2.2.4-trimethyl-1,3-bentanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, sucrose, aconitic acid,
Trimellitic acid, hemimellitic acid, ethylene diamine, propylene diamine, diethylene triamine, triethanolamine, pyrogallol, dihydrobenzoic acid, hydroxyphthalic acid, resorcinol, hydroquinone,
One or more compounds having at least two or more active hydrogen atoms in the molecule such as bisphenol A and suphenol F, 1,2-propanedithiol, etc., and ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, styrene oxide, etc. An addition polymer obtained by adding one type or two or more types is used.

As polyester polyol, ethylene glycol,
diethylene glycol, triethylene glycol,
1,2-propylene glycol, dipropylene glycol, trimethylene glycol, 1.4 or 1.3-butylene glycol, tetramethylene glycol, neopentyl glycol, 2,2-diethyl-1,3-propanediol, 2-n -Butyl-2-ethyl-13-propanediol, 2-ethyl-1,3-hexanediol, 2.2.4-trimethyl-1,3-bentanediol, hexamethylene glycol, decamethylene glycol, glycerin, trimethylol At least 2 in molecules such as propane, pentaerythritol, sorbitol, etc.
malonic acid, maleic acid, succinic acid, adipic acid, tartaric acid, pimelic acid, sebacic acid, oxalic acid, phthalic acid,
Terephthalic acid, hexahydrophthalic acid, aconitic acid,
A heavy metal compound condensed with one or more compounds having at least two carboxyl groups in the molecule, such as trimellitic acid and hemitrimellitic acid, is used.

Examples of polyisocyanates include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,
4 and 2.6-tolylene diisocyanate mixture, 4.
4'-diphenylmethane diisocyanate, m-phenylene diisocyanate, xylylene diisocyanate,
Tetramethylene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate ester, 1
4-cyclohexylene diisocyanate, 4,4 dicyclohexylmethane diisocyanate, 33'-dimethyl-4,4'-biphenylene diisocyanate 3.3'
-dichloro-4,4'biphenylene diisocyanate,
1,5-naphthalene diisocyanate, 1,5-tetrahydronaphthalene diisocyanate, etc. are used.

Crude products of tolylene diisocyanate and 4,4'-diphenylmethane diisocyanate, and modified products such as carbondiimide-modified 4,4'-diphenylmethane diisocyanate can also be used. The above organic polyisocyanates may be used alone or as a mixture of two or more.

Next, the plasticizer used in the present invention is a polyester plasticizer, which is obtained by reacting a dibasic acid, a glycol, and a terminal capping agent. The molecular weight of this polyester plasticizer is often 600 to 8,000.

This glycol component includes ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, and polyethylene glycol.
Propylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol and polypropylene glycol, butylene glycol, diethylene glycol, tributylene glycol,
Examples include tetrabutylene glycol and polybutylene glycol. Furthermore, 1.4 or 1.3-butylene glycol, tetramethylene glycol, neopentyl glycol, 2,2-diethyl-13-propanediol, 2-n-butyl-2-ethyl-1,3-70panediol, 2 -ethyl 13-hexanediol, 2.
Examples include 2.4-)-dimethyl-1,3-bentanediol, hexamethylene glycol, decamethylene glycol, and the like. Of course, these glycols can be used not only alone but also as a mixture of two or more.

As this glycol component, compound (1) represented by the following tR structure is preferable because it has a more pronounced bleed prevention effect.

A polyester plasticizer containing 1-10(R-〇)nH(1) (R is an alkylene group consisting of 2 to 4 carbon atoms, and the number of rl is 1 to 20) ideally has the following one-powder formula ( ■) or (Ilr).

T-G (A-G) Re T
([1>T-A (G-A) n T (m), where G is the residue of compound (1), A is the residue of dibasic acid, and T is the residue of monoalcohol or dibasic acid. Each represents a group.

Glycol components that have a remarkable bleed prevention effect include ethylene glycol, diethylene glycol,
triethylene glycol, tetraethylene glycol and polyethylene glycol, propylene glycol,
dipropylene glycol, tripropylene glycol,
Tetrapropylene glycol and polypropylene glycol, butylene glycol, diethylene glycol,
Includes tributylene glycol, tetrabutylene glycol, and polybutylene glycol.

As the dibasic acid related to A in the above general formula, for example,
Examples include saturated aliphatic dibasic acids such as adipic acid, azelaic acid, and sebacic acid, and aromatic dibasic acids such as phthalic acid, isophthalic acid, and terephthalic acid, or their anhydrides.

Of course, these dibasic acids can be used not only alone but also in a mixture of two or more. In addition, the monoalcohol or dibasic acid related to T is a terminal capping agent for polyester, and specifically, a saturated aliphatic alcohol and benzyl alcohol having 2 to 22 carbon atoms, preferably 6 to 18 carbon atoms, or a saturated fatty acid or alcohol having the same number of carbon atoms. It is agaric acid. Typical examples of such monoalcohols include inheptatool, n-octatool 52-ethylhexanol, innonanol, indecanol, stearyl alcohol, instearyl alcohol, epal 610,
E-pal 810 (Ethyl company product name), Lineball 79,
There are Lineball 911 (product name of Shell Co., Ltd.) and the like. Similarly, typical examples of -basic acids include 2-ethylhexanoic acid, lauric acid, myristic acid, stearic acid, and coconut oil fatty acid. Above - at maximum (II)
(m) is the case when a monobasic acid is used for T, and (m) is a monoalcohol for T, respectively.

In the above - maximum (■) (■), n represents an integer of 1 or more.

The present polyester plasticizer is produced by an esterification reaction or other various methods known to those skilled in the art.

For example, the molar ratio of glycol, dibasic acid, and end-stopper is important to obtain a polyester with a desired n value, but this molar ratio is not uniform; It is necessary to select an appropriate molar ratio depending on the type of agent (particularly the relative relationship of their vapor pressures). In addition, at the initial stage of the reaction, only the glycol and the dibasic acid are reacted in the presence or absence of a solvent such as toluene or xylene that can be azeotroped with water but is not compatible, and the appropriate fI! Once the value or hydroxyl value is obtained, a terminal capper can be added to continue the reaction. In this case, a monoalcohol as a terminal capping agent can also be used as the solvent.

The polyester production reaction is carried out using acid catalysts such as sulfuric acid, phosphoric acid, hydrochloric acid, zinc chloride, and sodium bisulfite, and metal compound catalysts such as dibutyl pot oxide, tetraisopropyl titanate, tin oxalate, antimony dioxide, and tin oxide. Typically, in the presence of these catalysts, the temperature at which water can be distilled off at atmospheric pressure is started by heating, and once water distillation is complete or essentially complete, the pressure is reduced; The pressure is usually between 1 and 15 mtlg at the end of the reaction to continue removing excess glycol and end capper.

The polyester plasticizer used in the present invention is usually 5 to 1 oott per 100 parts by weight of the urethane prepolymer.
Part t Particularly preferably, 5 to 80 parts by weight of the polyester plasticizer is incorporated. If the amount of the polyester plasticizer is less than 5 parts by weight, a sufficient plasticizing effect cannot be obtained, whereas if it is more than 10,111 parts by weight, sufficient adhesive strength and elasticity of the sealant can be obtained. I can't get it.

In practical use, an insoluble solvent and a catalyst for accelerating curing are usually added to the polyurethane sealant of the present invention.

The inert solvent may be any of the commonly used inert solvents, such as aromatic solvents such as toluene and xylene, esters, ketones, and ethers. It is preferable to distribute the amount at a ratio of less than 50%.

Examples of curing accelerating catalysts include N-alkylbenzylamine, N-alkylmorpholine, N-alkyl aliphatic polyamine, N-alkylpiperazine, triethylenediamine, 1,8-biazacyclo[5,4,O]Launsen-
7 and its derivatives, naphthenic acids or octenoates of heavy metals such as tin, lead, blue lead, cobalt, manganese, iron, mercury, dibutyl silk dilaurate, dibutyl tin malate,
Examples include heavy metal organic compounds such as di(phenylmercury) dodecenyl succinate, and these are usually preferably blended in a ratio of 101 parts or less to 1 part by weight of the urethane prepolymer IHt.

Furthermore, if necessary, it is also possible to mix and use fillers such as crosslinking agents such as polyalkylene glycol, various fillers, thixotropic agents, bituminous substances, and fillers such as t1.

Examples of such fillers include calcium carbonate, perlite, silicon oxide, talc, vermiculite, wollastonite, glass, carbon black, vinyl chloride resin, and the like.

Examples of thixotropic agents include bentonite, resin-coated bentonite metal soap, hydrogenated castor oil, and asbestos powder.

Examples of bituminous materials include coal tar, shale tar, real tar, oil gas tar, petroleum tar, petroleum asphalt, and pitches.

In the polyurethane sealant of the present invention, the amount of filler is preferably 2 to 1 part by weight, more preferably 10 to 1 part by weight, based on 100 parts by weight of the incyanate group-containing polymer.
The composition can contain 70 parts by weight.

Methods for using the polyurethane sealant of the present invention include, for example, an injection method in which the sealant is injected in liquid form into the gaps and joints of the target materials and hardened, and a spray method in which the undiluted solution is sprayed onto the joints of the materials and hardened. There are methods such as a brush coating method in which an undiluted solution is applied to the material with a brush and hardened, and an installation method in which a pre-cured sealant is attached as it is or a processed sealant is attached to fill the gap.

However, since the composition of the present invention does not cause any plasticizer bleed phenomenon, the excellent properties originally possessed by urethane sealants such as adhesiveness, elasticity, cold resistance, and stain resistance are permanently maintained. The present invention was completed by discovering the novel fact that

The polyurethane sealant of the present invention can be used, for example, at each joint of various buildings or structures such as corrugated boards, slates, plastic boards, aluminum boards, galvanized iron, joints in concrete, ceramic pipes, glass, etc., joints in roads and floor coverings, automobiles, etc. It can be used as a joint material, adhesive, caulking material, etc. for the joints and joints of vehicles such as ships and aircraft, and the joints of pipes and prefabricated buildings, and the bleeding phenomenon of plasticizer is noticeable as in the present invention. It is extremely useful industrially to be able to prevent this.

Next, the present invention will be explained in more detail with reference to Examples.
"%J" Part J is based on weight unless otherwise specified.

Example 1 12312 parts of adipine a, 245 parts of diethylene glycol
A reaction vessel was charged with 104 parts of 2-ethylhexanol and 0.15 parts of tetraisopropyl titanium as a reaction catalyst, and the mixture was stirred and heated in a nitrogen gas stream for 7 hours while continuously distilling off the produced water. The temperature was raised to 220°C and further maintained at that temperature until the acid value became 20 or less.Then, the pressure was reduced at that temperature to lower the acid value and the R height was 1.
After reducing the pressure to ~2 llmHg to remove excess alcohol and low-boiling seafood, the mixture was cooled to 100°C and filtered to obtain polyester plasticizer 3.

A polyurethane sealant having the following composition was prepared using this polyester plasticizer.

Polypropylene glycol urethane prepolymer (NC○ content 25%) 100 parts The above polyester plasticizer 30 parts Titanium oxide
20 parts calcium carbonate
50 parts methylhexahydrophthalic anhydride (M
Medium) 5 parts polypropylene glycol (Crosslinking agent) 15 parts toluene
A bleed test was conducted on 20 parts of the sealant.

(1. Silica sand adhesion) A 15c+s square slate board is made with a gap of 5c@ in the center, and a slate board of 7.5c x 15 parts is glued on both sides.

Apply a stopper sponge to both ends of the groove, pour polyurethane of the above composition into it, and after curing, apply acrylic emulsion paint to the entire surface. Thereafter, it is left in a constant temperature bath at 50°C, and after a certain period of time, it is sprinkled with silica sand to check the degree of bleeding.

Items with little silica sand adhesion are good.

(29-page paper permeability) 5 sheets of paper are stacked on top of each other, and at the top, a width of 2 cm and a thickness of ICff are placed.
1. Form a sealant coating film with a length of 10 cm, and after one week observe how many sheets of paper the plasticizer has bled into.

(3. Contamination) Contamination due to bleeding on the surface of the sealant was also measured based on JIS^5758.

(4 Adhesive Strength) The adhesive strength of the sealant was tested by applying a wave film of alkyd resin on the sealant coating film, and after drying, cellophane tape was adhered and then peeled off.

Example 2 The same experiment as in Example 1 was conducted except that 245 parts of diethylene glycol was replaced with 924 parts of polypropylene glycol (average molecular weight Ji 400).

Example 3 The same experiment as in Example 1 was conducted except that 245 parts of diethylene glycol was replaced with 370 parts of 2-n-butyl-2-ethyl-1,3-propanediol.

Comparative fIAl Di-2-ethylhexyl phthalate (DOP) was used in place of the polyester plasticizer in the composition of the polyurethane sealant.

Table 1: No or almost no silica sand adheres.A slight amount of silica sand adheres.A considerable amount of silica sand adheres.Silica sand adheres and the entire surface is pitch black.

Claims (2)

[Claims] (1) A urethane sealant composition containing a urethane prepolymer and a polyester plasticizer. (2) The above plasticizer is a compound represented by the following structure (
Claim 1 using a polyester plasticizer synthesized from the polyether polyol and dibasic acid of I)
The urethane sealant composition described in . HO(R-O)_nH(I) (R is an alkylene group consisting of 2 to 4 carbon atoms, the number of n is 1
~20)