JP2006206708A - Urethane primer composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a one pack type urethan primer composition capable of eliminating indoor environmental pollution accompanying with the use of toluene, xylene, etc., excellent in solubility with a urethan prepolymer, and also excellent in close adhesion with concrete, mortar, plywood and calcium silicate-underlying material, and durability. <P>SOLUTION: This one pot type urethane primer composition obtained by mixing 10-50 pts.wt. urethane prepolymer, 5-35 pts.wt. methylcyclohexane and 15-85 pts.wt. organic solvent as another solvent without containing a vaporizable organic compound such as an alcohol, formaldehyde, toluene, xylene, p-dichlorobenzene, ethylbezene and styrene is excellent in dissolution property, close adhesion to the concrete, mortar, plywood and calcium silicate-underlaying material, and durability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention provides adhesion, durability to concrete, mortar, plywood, and calcium base as a painted floor used in the field of construction, particularly waterproofing. In the urethane primer composition, toluene, xylene, formaldehyde, parachlorobenzene, The present invention relates to an environment-friendly urethane primer composition that does not use ethylbenzene or styrene.

Conventionally, urethane primers have been used to provide adhesion and durability to concrete floors, concrete, mortar, plywood, and calcium base as a coating floor used in the civil engineering / architecture field, especially for waterproofing.

However, toluene and xylene are used as solvents for conventional urethane primers because of their excellent compatibility and solubility (see Patent Documents 1 and 2). However, in recent years, the Ministry of Health, Labor and Welfare has established priority substances such as formaldehyde, toluene, and xylene as indoor pollutants for sick house syndrome, and is a first-class designated chemical substance under the PRTR Law (Chemical Emission Control Management Promotion Law) Formaldehyde, benzene, toluene, xylene, etc. are specified. In addition, the Ministry of Education, Culture, Sports, Science and Technology revised the school environmental hygiene standards to take measures against indoor air pollution at schools. Formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, Criteria for volatile organic compounds of styrene were applied. In such a background, development of a urethane primer that does not contain the chemical substance is desired from the market.
Patent No. 3027854 JP 2003-221426

The present invention eliminates indoor environmental pollution associated with the use of toluene, xylene, etc., has excellent solubility with urethane prepolymer, and has excellent adhesion to concrete, mortar, plywood, and calcium substrate, and has excellent durability. The purpose is to obtain.

In order to solve the above problems, urethane prepolymer 10-50 parts by weight, methylcyclohexane 5-35 parts by weight, and other organic solvents do not contain volatile organic compounds of formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene The urethane primer composition obtained by mixing 15 to 85 parts by weight of an organic solvent does not contain organic compounds of formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, and styrene, which are the cause of environmental pollution, and is soluble. The urethane primer composition is excellent in adhesion, adhesion to concrete, mortar, plywood and calcium base, and durability.

Hereinafter, the present invention will be described in detail.
The urethane prepolymer used in the present invention is obtained by reacting an equivalent ratio of NCO / OH of 1.2 to 2.0 on average in the reaction of polyols and organic diisocyanates. It is a curable urethane prepolymer, and the hardness and viscosity can be set by the polyol composition so as to be suitable for concrete, mortar, plywood and calcium base.

Examples of such polyols include polyhydric alcohols having 2 to 3 hydroxyl groups in one molecule, such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-butylene glycol, 1,4-butylene. Of a copolymer obtained by polymerizing glycol oxide, 1,6-hexanediol, neopentyl glycol, bisphenol A, trimethylol ethane, trimethylol propane, glycerin, or the like with an alkylene oxide such as propylene oxide, butylene oxide, or styrene oxide. A polyalkylene ether polyol having an average molecular weight of preferably 200 to 800 can be used.

Moreover, the diisocyanate used for normal urethane resin can be used for organic diisocyanate. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4 / 2,6 isomer ratio 65/35 (weight ratio) tolylene diisocyanate, 2,4 / 2,6 isomer ratio 80 / 20 (weight ratio) tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, metaxylylene diisocyanate, phenyl diisocyanate, 1,5-naphthalene diisocyanate, water-added tolylene diisocyanate, water-added 4,4'- Diphenylmethane diisocyanate, isophorone diisocyanate, etc., alone or as a mixture, preferably liquid at normal temperature and easy to handle are suitable.

Thus, the produced urethane primer is 10 to 50 parts by weight or less, preferably 30 to 40 parts by weight or less based on the total weight. When the amount of the urethane primer is less than 10 parts by weight, it is difficult to obtain sufficient adhesion and durability, and when it exceeds 50 parts by weight, it is difficult to obtain compatibility with the solvent, and the permeability to the substrate is poor and the adhesion is lowered. To do. The number average molecular weight of the urethane prepolymer thus produced is preferably 700 to 1400. When the number average molecular weight is less than 700, the curing time becomes long and workability is deteriorated. When the number average molecular weight exceeds 1400, the viscosity becomes high and the adhesion to the substrate is deteriorated.

The solvent used in the present invention does not contain organic compounds of formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, and styrene, which are substances causing environmental pollution, and is an organic solvent that does not react with isocyanate groups, For example, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, cyclohexanone, methyl cyclohexane, tetrahydrofuran, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, pentyl acetate, cellosolve, methyl cellosolve, butyl cellosolve, sorbite and the like can be mentioned. Of these, methylcyclohexane is an essential solvent, and a mixed solvent containing at least one of methyl ethyl ketone, ethyl acetate, and butyl acetate is compatible and soluble with the urethane prepolymer, and further, the drying property of the urethane prepolymer and the base. It is preferable because of its excellent permeability and adhesion.

The amount of solvent used varies depending on the type and viscosity of the mixture, but the amount of methylcyclohexane used is 5 to 35 parts by weight or less, preferably 10 to 20 parts by weight or less based on the total weight. Yes. If methylcyclohexane is less than 5 parts by weight, it is difficult to obtain sufficient solubility with the urethane prepolymer, and if it exceeds 35 parts by weight, drying of the urethane prepolymer is accelerated, which is not suitable. In addition, methyl ethyl ketone, ethyl acetate, and butyl acetate are used in an amount of 15 to 85 parts by weight, preferably 40 to 60 parts by weight, based on the total weight in a mixed state. If the amount of methyl ethyl ketone, ethyl acetate, or butyl acetate is less than 15 parts by weight, it is difficult to obtain sufficient solubility in the urethane prepolymer, and if it exceeds 85 parts by weight, the curing time is delayed.

The urethane primer composition of the present invention can contain an antifoaming agent, an anti-aging agent, a stabilizer, a reinforcing agent, and a crosslinking agent, which are generally used, in addition to the above components, as necessary.

Urethane primer composition obtained according to the present invention includes indoor contaminants of sick house syndrome, first-class designated chemical substances of the PRTR method, formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene designated by school environmental health standards. It was possible to obtain a urethane primer composition excellent in solubility with a urethane prepolymer, excellent in adhesion to concrete, mortar, plywood and calcium base, and excellent in durability.

Hereinafter, although an example and a comparative example explain concretely, the present invention is not limited to these examples.

Examples and Comparative Examples Urethane primer compositions of Examples and Comparative Examples were prepared according to the formulations shown in Table 1.
Example 1
It is an isocyanate group-containing compound obtained by urethanization reaction of TDI (2, 4, or 2, 6-tolylene diisocyanate) and PPG (polypropylene glycol) having an average molecular weight of about 300 to 400, and its average molecular weight is about 700 Mixing 40 parts of urethane prepolymer (L-1150: manufactured by Mitsui Takeda Chemical Co., Ltd.), 20 parts of methylcyclohexane, 20 parts of methyl ethyl ketone, 10 parts of ethyl acetate, 10 parts of butyl acetate, and having a base of concrete. Then, 0.2 kg / m ² was applied with a roller and cured under conditions of 23 ° C. × 50% RH × 7 days, and the physical properties of the coating film thereafter were evaluated.
Comparative Example 1
40 parts of urethane prepolymer (L-1150: manufactured by Mitsui Takeda Chemical Co., Ltd.) obtained by the same reaction as in Example 1, 30 parts of toluene, 20 parts of methyl ethyl ketone, and 10 parts of ethyl acetate were mixed to form a concrete base. 0.2 kg / m ² was applied with a roller and cured under conditions of 23 ° C. × 50% RH × 7 days, and the physical properties of the coating film thereafter were evaluated.
Comparative Example 2
40 parts of urethane prepolymer (L-1150: manufactured by Mitsui Takeda Chemical Co., Ltd.), 20 parts of isohexane, 15 parts of methylcyclohexane, 15 parts of methyl ethyl ketone, 5 parts of ethyl acetate, 5 parts of ethyl acetate, obtained by the same reaction as in Example 1. 5 parts were mixed, 0.2 kg / m ² was applied to the concrete base with a roller and cured under the conditions of 23 ° C. × 50% RH × 7 days, and the physical properties of the coating film thereafter were evaluated.
Comparative Example 3
60 parts of urethane prepolymer (L-1150: manufactured by Mitsui Takeda Chemical Co., Ltd.) obtained by the same reaction as in Example 1, 15 parts of methylcyclohexane, 15 parts of methyl ethyl ketone, 5 parts of ethyl acetate and 5 parts of butyl acetate were mixed. Then, 0.2 kg / m ² was applied to the concrete base with a roller and cured under conditions of 23 ° C. × 50% RH × 7 days, and the physical properties of the coating film thereafter were evaluated.

Table 1





The viscosity was measured with a Brookfield rotary viscometer under the conditions of BM type, No. 1, 60 rpm.

In the Examples and Comparative Examples, the adhesion test was measured and evaluated by the following methods. The results are shown in Table 1. In Example 1, a clear cured coating film was obtained that did not contain toluene, and was excellent in adhesion to the concrete base and water resistance. In the comparative example 1, although quality is good, it contains toluene and does not consider the environment. In Comparative Example 2, due to the influence of solvents other than the claims, the cured coating film became cloudy and poor in water resistance due to poor compatibility with the urethane prepolymer. In Comparative Example 3, the viscosity of the mixture was significantly increased at parts by weight of the urethane prepolymer other than that in the claims, and the mixture did not penetrate into the concrete base and adhesion was significantly inferior.

Adhesion test
Adhesion with a cured coating film using 0.2 kg / m2 applied to a concrete plate of JIS A 5371 in the composition of Example and Comparative Example and cured for 7 days at 23 ° C and 50% RH. As a property test, in accordance with JIS A 5536, a vertical and horizontal 40 mm square adhesive surface and a steel jig with a thickness of 20 mm were bonded to the surface of the specimen, and a tensile test was conducted with a Kenken tensile tester. Checked the condition.
Water resistance test
0.2 kg / m 2 was applied on a JIS A 5371 concrete flat plate in the composition of Examples and Comparative Examples, and 2 ml of water droplets were dropped after 8 hours at 23 ° C. and 50% RH. After 24 hours, the degree of whitening of the coating film surface was visually confirmed.
○: No whitening, Δ: Partial whitening, ×: Total whitening.

Claims (3)

In the total weight composition, urethane prepolymer 10-50 parts by weight, methylcyclohexane 5-35 parts by weight, and other solvents not containing volatile organic compounds of formaldehyde, toluene, xylene, paradichlorobenzene, ethylbenzene, styrene 15 to 85 parts by weight of a urethane primer composition, 2. The urethane primer composition according to claim 1, which is a moisture curable urethane prepolymer having a number average molecular weight of 700 to 1400 as the urethane prepolymer. 3. The urethane primer composition according to claim 1, wherein the other solvent is at least one selected from methyl ethyl ketone, ethyl acetate, and butyl acetate.