JPH07268051A - Thermally curable urethane composition - Google Patents

Abstract

PURPOSE:To obtain the subject compsn. which is useful for an adhesive, a sealant, and a coating material and meets the quality specifications esp. for a jointing material for clay pipes. CONSTITUTION:This urethane compsn. is prepd. by compounding a base component with an at least difunctional epoxy resin. The base component comprises at least either a polyisocyanate compd. or an active-isocyanate-terminated urethane prepolymer (obtd. by reacting a polyol with an excess of a polyisocyanate compd.) and a liq. dispersion comprising a solid amine and a liq. paraffin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-curable urethane composition, more specifically, an amine-dispersed heat-curable urethane composition containing a bifunctional or higher functional epoxy resin. It is useful as a coating material, and by mixing the epoxy resin, it imparts elastic and tough physical properties to improve the compression set, etc., and is a one-component solventless heat-curing type that can meet the quality standards of joint materials for ceramic pipes. -Related urethane composition.

[0002]

2. Description of the Related Art Conventionally, as a heat-curable composition of amine dispersion type in which a polyamine compound is dispersed in a so-called isocyanate component,
For example, an adhesive or sealing material prepared by mixing a dispersion liquid of solid amine and liquid paraffin at 40 ° C. or lower with a urethane prepolymer containing an end-active isocyanate group obtained by reacting a polyol component with an excess amount of a polyisocyanate compound. There is known a heat-curable urethane composition applicable to (see JP-A-5-32948).
This known composition is excellent in low-temperature curability because it cures at a temperature of the melting point of solid amine + 20 ° C. (for example, 80 ° C.), but it lacks particularly compression set as a cured physical property and is industrially practical (for example, It did not reach the quality standard of the joint material for pottery tubes, JIS-R-1201).

[0003]

Therefore, the present inventors have
As a result of intensive research to improve such compression set, the known composition of the amine dispersion type was used as a base component,
If a bifunctional or higher functional epoxy resin is blended with this, in addition to the reaction between the isocyanate component and the solid amine, the reaction between the epoxy resin and the solid amine occurs, and a network structure is formed based on this three-dimensional reaction, which results in elasticity. It was found that the polyisocyanate compound itself can be used as an isocyanate component instead of or in combination with the urethane prepolymer containing an end-active isocyanate group, and has completed the present invention. .

That is, the present invention relates to (A) a polyisocyanate compound and a urethane prepolymer having a terminal active isocyanate group obtained by reacting an excess amount of a polyisocyanate compound with a polyol component, respectively, or a mixture thereof; and ( B) A heat-curable urethane composition comprising a base component composed of a dispersion liquid of solid amine and liquid paraffin, and a bifunctional or higher functional epoxy resin blended therein.

As the above-mentioned polyisocyanate compound in the present invention, any one belonging to aromatic, aliphatic or alicyclic may be used, for example, tolylene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate, 3 , 3'-Dimethyl-4,4'-biphenylene diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethyl xylylene diisocyanate, naphthylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, crude TDI, polymethylene Polyphenyl isocyanate, isophorone diisocyanate, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, their isocyanurates, carbodiimides, bures Products and the like, may be subjected to one kind of them or a mixture of two or more in use. Aromatic polyisocyanate compounds are particularly preferable.

The above-mentioned urethane prepolymer containing a terminal active isocyanate group (NCO) in the present invention (hereinafter referred to as a terminal NCO prepolymer) contains an excessive amount of polyisocyanate compound in an ordinary polyol component, for example, OH /.
It can be produced by reacting so that the equivalent ratio of NCO is 1 / 1.2-3.5. The reaction is carried out if necessary with a suitable reaction solvent (eg ethyl acetate, toluene, xylene) and a reaction catalyst (eg dibutyltin dilaurate or other organotin catalyst, bismuth octylate or other bismuth catalyst, 1,4-diaza [2] [2.2.2] In the presence of a tertiary amine-based catalyst such as bicyclooctane, usually at room temperature to 60.
It can be carried out under the conditions of ~ 90 ° C for 1 to 7 hours. The terminal NCO-containing prepolymer obtained usually has a terminal NCO content of 0.5 to 5% (% by weight, hereinafter the same) and a viscosity of 5000.
It suffices if it is set to -500000 cps / 20 ° C.

Examples of the polyol component include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol and sucrose, and propylene oxide or propylene oxide and alkylene oxide such as ethylene oxide. Addition-polymerized polyether polyols; ethylene glycol,
Propylene glycol and these oligoglycols; butylene glycol, hexylene glycol, polytetramethylene ether glycols; polycaprolactone polyols; polyester polyols such as polyethylene adipate; polybutadiene polyols; having hydroxyl groups such as castor oil Higher fatty acid esters; polymer polyols obtained by grafting vinyl monomers onto polyether polyols or polyester polyols, and the like.

In the present invention, as the component (A) which is an isocyanate component, the above-mentioned polyisocyanate compound itself, the prepolymer containing terminal NCO or a mixture thereof is used.

The above-mentioned solid amine in the present invention includes
Any of aromatic, aliphatic or alicyclic compounds having a melting point of 50 ° C. or higher may be used, for example, 4,4′-
Diaminodiphenylmethane, 2,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane,
3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 2,4'-diaminobiphenyl, 3,
3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o-phenylenediamine, m-phenylenediamine, 2,3-tolylenediamine, 2,4-tolylenediamine, 2,5- Aromatic such as tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine, 1,12-dodecanediamine,
Aliphatic compounds such as 1,10-decanediamine, 1,8-octanediamine, 1,14-tetradecanediamine, and 1,16-hexadecanediamine may be mentioned, and one or a mixture of two or more thereof may be used. Good. Such solid amine is preferably used with an average particle size of, for example, 5 to 30 μ.

The solid amine and liquid paraffin are usually mixed in a weight ratio of 1/5 to 1/1 to form a dispersion, which is used as the component (B) in the present invention. The amount used is usually such that the equivalent ratio (NCO / NH ₂ ) of NCO of the isocyanate component (A) and amino group (NH ₂ ) of the solid amine is 1 /.
It may be selected so as to be 0.7 to 1.5, preferably 1 / 0.9 to 1.3. When the ratio of NH ₂ is less than 0.7, desired cured physical properties cannot be obtained, and when it exceeds 1.5, the cured product tends to be colored.

Examples of the epoxy resin in the present invention include bisphenol A type, F type, AD type, phenol type, cresol type, cycloaliphatic type, glycidyl ester type, glycidyl amine type and the like, and particularly liquid type preferable. When the compounding amount of the epoxy resin is set to 3% (% by weight, the same applies hereinafter) or more in the total amount of the system, the effect of physical properties of the epoxy resin is exhibited. In addition, as a cured physical property, J
20 to pass the IS-R-1201 quality standard
% Or less. If it exceeds 20%, the elasticity of the urethane cured product tends to be impaired. However, when the cured physical properties of the epoxy resin are desired, the amount of the epoxy resin can be increased. In particular, the one-component low temperature curing type epoxy resin composition can be prepared by blending a dispersion liquid of solid amine as the component (B) and liquid paraffin in the epoxy resin.
In this case, the amino group is blended so as to have an approximately equivalent ratio to the epoxy group.

The heat-curable urethane composition according to the present invention is composed of a solvent-free system in which the above-mentioned epoxy resin is blended with a base component consisting of the above-mentioned isocyanate component (A) and solid amine dispersion (B). It In such a composition constitution, the solid amine starts to react with the isocyanate component (A) and also with the epoxy resin by heating and melting. Therefore, under the conditions below the melting point of the solid amine, even if the epoxy resin is added to the base component,
No reaction occurs and the fluidity of the entire system is maintained. On the other hand, when heat is applied to a temperature higher than the melting point of the solid amine, two reactions simultaneously proceed, resulting in a network structure due to three-dimensionalization (increased crosslink density), and the elastic and tough physical properties of the initial purpose (especially A cured product having an effective compression set) is formed.

For the purpose of stabilizing the storage of the system or adjusting the physical properties, a plasticizer and / or a filler may be added in an appropriate amount, if necessary. Examples of the plasticizer include phthalic acid derivatives (for example, dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl benzyl phthalate), isophthalic acid derivatives, tetrahydrophthalic acid derivatives, adipic acid derivatives ( Adipic acid ester), azelaic acid derivative, sebacic acid derivative, maleic acid derivative, fumaric acid derivative, trimellitic acid derivative, pyromellitic acid derivative,
Examples thereof include an oleic acid derivative, a stearic acid derivative, a paraffin derivative (for example, chloroparaffin), trioctyl phosphate, an epoxy plasticizer, toluene-sulfoamide, castor oil and the like. The addition amount is usually selected in the range of 10 to 30% in the total amount of the system.

Examples of the filler include heavy calcium carbonate, calcium carbonate surface-treated with fatty acid, carbon black, silicic acid anhydride, clay, talc, mica,
Examples include fibrous materials and metal powders, and the use of clay is particularly advantageous for stabilizing storage. The addition amount may be usually selected in the range of 5 to 20% in the total amount of the system. Furthermore, as other additives, a urethane catalyst, a thixotropic agent, an ultraviolet absorber, an antiaging agent, a dye / pigment, an adhesive agent, a dehydrating agent and the like may be added in appropriate amounts. As the urethane catalyst, DBU
[1,8-diazabicyclo (5.4.0) undecene-
7], DBU phenol salt, DBU octylate, DB
U formates such as DBU; monoamines (triethylamine, etc.), diamines (N, N, N ', N'-tetramethylethylenediamine, etc.), triamines (tetramethylguanidine, etc.), cyclic amines (triethylenediamine, etc.), alcohol amines (Dimethylaminomethanol, etc.), ether amines [bis (2-dimethylaminoethyl) ether, etc.], amines; Sn (dibutyltin dilaurate, tin octylate, etc.), Pb (lead octylate, etc.), Zn
Organic carboxylic acid metal salts such as a system (zinc octylate, etc.);
Examples thereof include imidazole compounds such as 2-methylimidazole and 1,2-dimethylimidazole.

[0015]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the example sentence, "part" means "part by weight". Examples 1 to 4 and Comparative Example 1 (1) Production of Prepolymer Containing Terminal NCO: 100 g of polyoxypropylene diol having a hydroxyl value of 29.0 mg KOH / g and hydrogenated 1,4-butadiene-based polyol having a hydroxyl value of 51.8 mg KOH / g. 176g, 4,
170 g of 4'-diphenylmethane diisocyanate was added (OH / NCO = 1 / 2.0) and reacted at 80 ° C. for 10 hours to give a terminal NCO content of 2.12% and a viscosity of 20000 c.
A terminal NCO containing prepolymer with ps / 20 ° C. is obtained.

(2) Preparation of solid amine dispersion liquid 1,12-dodecanediamine / liquid paraffin (weight ratio = 25/75) was sufficiently mixed with a high speed mixer to prepare a slurry liquid in which fine particle diamine was dispersed. obtain.

(3) Preparation of heat-curable urethane composition The weight ratio of the terminal NCO-containing prepolymer of (1) above and the diamine-dispersed slurry solution of (2) above is 83.2 /
A ratio of 16.8 (ie NCO / NH ₂ = 1/1.
0) were mixed to form a base component, and epoxy resin [Epicoat 807 and Epicoat 604 manufactured by Yuka Shell Co., Ltd.] and a plasticizer [dioctyl phthalate (DOP)] were added in the proportions (parts) shown in Table 1 below. A filler (calcium carbonate, clay) and the terminal NCO-containing prepolymer of (1) above are blended to prepare a heat-curable urethane composition.

Performance Test (1) Curability at 100 ° C. and Measurement of Physical Properties Each composition was coated on a release paper at a dry film thickness of 2.0 mm and
After heat-curing at 00 ° C. for 10 minutes, physical properties, hardness (Shore A) and compression set (JIS K6301) of the cured film to be formed were measured, and the results are shown in Table 1. (2) Storage stability Each composition was sealed and stored at 40 ° C., and the increased viscosity after 7 days was measured (however, the viscosity immediately before storage is 100), and the results are shown in Table 1.

[0019]

[Table 1]

[0020]

EFFECTS OF THE INVENTION According to the composition of the present invention, while maintaining good storage stability and low temperature curing property, for example, 100
By heat-curing at ℃ × 10 minutes, a tough cured film with less compression set can be formed, and in particular, it can meet the quality standard JIS-R-1201 of the joint material for ceramic pipes. In addition, it can be applied to septic tank sealing materials, anti-slip materials, etc., and can also be used for one-component low-temperature thermosetting epoxy resin compositions, while no harmful gas is generated during the curing reaction. Since it is solvent-free, it is also advantageous in terms of safety and hygiene.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location C09J 175/04 JFA JFF (72) Inventor Lockoshi Goto 7-1 Akita-cho, Takatsuki-shi, Osaka Sunstar Giken Co. In the company

Claims (3)

[Claims] 1. A polyisocyanate compound (A) and a urethane prepolymer containing a terminal active isocyanate group obtained by reacting a polyol component with an excess amount of a polyisocyanate compound, respectively, or a mixture thereof.
And (B) a dispersion liquid of solid amine and liquid paraffin; and a bifunctional or higher functional epoxy resin mixed with a base component. 2. The heat-curable urethane composition according to claim 1, further comprising a plasticizer and / or a filler. 3. The heat-curable urethane composition according to claim 2, wherein at least clay is used as a filler.