JPS6011058B2 - Thixotropic polyurethane composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a swingable polyurethane composition that flows and becomes a sol when an external force is applied during use, but does not have fluidity and becomes a gel when in a static layer state.

- When polyurethane compositions are applied to vertical surfaces or sloped surfaces as sealants, adhesives, coatings, wall materials, etc., they flow with an appropriate viscosity during construction and do not cause run-off or dripping after processing. It is important to have the property of maintaining a predetermined shape without forming, that is, bridge degeneration (thixotropic property).

Conventionally, methods for obtaining Sun-modified polyurethane compositions include a method using a combination of colloidal silica and a polyethylene glycol derivative as disclosed in Japanese Patent Publication No. 4111-P, Samurai Publication No. 7632-1977, General No. 99 of 1971, etc.;
Method of using a large amount of inorganic filler and polyalkylene compound with special structure in combination with silk and oxyethylene unit 1
A method is disclosed in which colloidal silica is used in combination with a random polyalkylene compound containing 0-7% weight units.

Also, REINHOLD PUBLISH dish GC
ORPORATIONI 967 edition “Sealant”
Pages 144 to 146 describe a method for preventing sagging of urethane compositions. However, the above-mentioned thixotropy improvers used in these methods show that the composition obtained by adding a small amount of these dispersion improvers shows a considerable increase in viscosity, which impairs workability, and There is a drawback that the viscosity of the composition increases or gels during storage due to adhesion of modifiers active against isocyanate groups such as moisture. In addition, these modifiers include diphenylmethane-4
, 4' diisocyanate-based prepolymers have drawbacks such as insufficient dispersion improvement effect or loss of the improvement effect during storage. The present invention was made in order to eliminate such drawbacks, and an object of the present invention is to provide a novel bridge-modified polyurethane composition having excellent storage stability and the like.

As a result of various studies to achieve this objective, the present inventor has found that a desired composition can be obtained by adding carbon black and a specified benzene cyclic carboxylic acid ester to an isocyanate group-terminated polyurethane polymer. The present invention was realized based on the knowledge that

Therefore, the bridge-modified polyurethane composition of the present invention prepared in this manner contains 10 to 150 parts by weight of 1-carbon black and 10 to 150 parts by weight of 1-carbon black and benzene having the following formula. It is characterized by adding 1 to 15 parts by weight of a cyclic carboxylic acid ester.

In the above formula, n is 0 to 3, R and R' are alkyl groups, R' has 1 to 8 carbon atoms, and when n=0, R has 4 to 8 carbon atoms, When n=1 to 3, R'
When the carbon number of is 1, 4-18 When the carbon number of R' is 2-4, 9-18 When the carbon number of R' is 5-8, 12-18
It is 18. Hereinafter, the configuration of the present invention will be explained in detail. The isocyanate group-terminated polyurethane polymer (hereinafter referred to as polyurethane prepolymer) used in the present invention is a known one obtained by reacting an organic compound having at least two active hydrogens with an organic polyisocyanate. Organic compounds having at least two active hydrogens (hydrogen atoms active with respect to isocyanate groups) include polyoxy(low) alkylene polyols (diols, triols, tetraols, bentols) with a molecular weight of 134 or more and which are liquid at room temperature. and mixtures thereof), polyester polyols made of low molecular weight polyols such as ethylene glycol and propylene glycol, and low molecular weight compounds such as polycarboxylic acids such as adipic acid, and other known polyols. In addition, examples of the organic polyisocyanate include diphenylmethane-4,4 diisocyanate, tolylene diisocyanate,
Known diisocyanates such as hexamethylene diisocyanate and xylylene diisocyanate, and polyisocyanates having two or more isocyanate groups in one molecule such as polymethylene polyphenylisocyanate are used alone or in combination. The mixing ratio of these two components and the method of producing a polyurethane prepolymer by reacting both components are not particularly limited, and methods well known to those skilled in the art may be used. Further, the carbon black used in the present invention may be any of channel black, furnace black, thermal black, and lamp black, but depending on the purpose of application of the final composition,
Those that have been tested to obtain desirable strength, workability, storage properties, etc. are used.

Generally, thermal black, furnace black, and channel black with a low volatile component content are used alone or in combination. Furthermore, in the present invention, a benzene cyclic carboxylic acid ester having the following formula is used.

In the above formula, n is 0 to 3, R and R are an alkyl group, R' has 1 to 8 carbon atoms, and R has 4 to 8 carbon atoms when n=0. , in the case of n=1 to 3, when the number of carbon atoms in R' is 1, the number of carbon atoms in R' is 2 to 18
9 to 18 when 4, 1 when R' has 5 to 8 carbon atoms
2 to 18. When the number of carbon atoms in the alkyl group of R' is 9 or more, thixotropy improvement efficiency cannot be obtained. Furthermore, if the number of carbon atoms in the alkyl group of R exceeds 18, the handling efficiency of the compound (benzene cyclic carboxylic acid ester) is poor, which is not preferred in practice. When the carbon numbers of R and R' become close, the effect of improving bridge modification cannot be obtained. Note that the carboxyl group may be located at any position. Examples of this compound include the following, but two or more of these may be used together. n-butyl benzoate, n-stearyl benzoate, methyl n-butyl phthalate, methyl n
-stearyl phthalate, ethyl isode, sil phthalate, ethyl n-stearyl phthalate, n-butyl n
-Stearyl phthalate, n-amyl lauryl phthalate, 2-ethylhexyl lauryl phthalate, 2-ethylhexyl n-stearyl phthalate, 1,2-n-butyl n-stearyl trimellitate, 1,2,4 tri-
n-Butyl n-stearyl pyromellitate, n-butyl n-stearyl isophthalate, 1,2 di-n-butyl n-stearyl hemimellitate, 1,3 di-n-butyl n-stearyl trimesate. In the present invention, based on 10 parts by weight of the polyurethane prepolymer, 10 to 15 parts by weight of carbon black and 1 to 15 parts by weight of the above-mentioned benzene cyclic carboxylic acid ester, preferably 4 to 15 parts by weight, are used.
Add 2 parts by weight and use it. A bridge-modified polyurethane composition is thereby obtained. Incidentally, in order to obtain the bridge-modified polyurethane composition of the present invention, the respective components may be combined in any manner. Cured physical properties of this composition,
Properties such as workability can be changed by adding suitable compounding agents that are inert towards isocyanate groups. The amounts and types of ingredients to be mixed will depend on the intended use of the composition, but useful ingredients include fillers that are inert to isocyanate groups, such as talc, calcium carbonate, silica powder, and titanium dioxide (usually polyurethane fillers). (50 to 30 parts by weight per 100 parts by weight of polymer), common inert plasticizers such as phthalates such as dioctyl phthalate and diisodecyl phthalate, and chlorinated paraffins (
Typically, 1 to 10 parts by weight of polyurethane prepolymer
5 parts by weight or less), aromatic solvents such as toluene and xylene,
General inert solvents such as esters and ketoso compounds (usually 15 parts by weight or less per 100 parts by weight of polyurethane prepolymer), and if necessary, trimethylene diamine, dibutyltin dilaurate, stannous diethyl Curing catalysts such as hexoate are also added. Organic and inorganic inert colorants can also be used. Although the present composition is cured by the action of moisture in the air, curing may be accelerated by adding a polyol or polyamine having two or more of the above-mentioned active hydrogens per molecule, water, or the like.

It is not clear why the above-mentioned cyclic carboxylic acid ester compound and carbon black exhibit a high dispersion improvement effect in polyurethane compositions without showing an extreme increase in viscosity, but the urethane prepolymer, carbon black, and the above-mentioned compounds This is presumed to be the result of intermolecular interactions.

Examples and reference examples are illustrated below.

Examples 1 to 1 & Reference Examples 1 to 5 After purging with dry nitrogen gas, about 5 pi
82 parts by weight of diphenylmethane-4,4
’-diisocyanate with an average molecular weight of about 60.
Adding 60 parts by weight of polyoxypropylene triol of 00 to 8000, the content of isocyanate groups was 2.9.
% by weight, and then 1 part by weight of a 0.25% solution of stannous di(2-ethylhexoate) (total tin content 28%) in dry toluene was added to give an isocyanate group content of 1.9% by weight. The reaction was continued until it reached %.

The mixture was then cooled to room temperature to obtain a polyurethane prepolymer. 100 parts by weight of this polyurethane prepolymer were put into a rice bran mixer purged with dry nitrogen gas, and parts by weight of furnace thermal plaque 9, which had been previously dried under reduced pressure to a water content of 0.0% by weight or less, and calcium carbonate. 1
and 1 part by weight of diisodecyl phthalate were added and kneaded in a sealed container. Next, 5 parts by weight of the thixotropy improver shown in Table 1 was added and kneaded under reduced pressure to obtain a composition of the present invention. Next, this polyurethane composition was sealed in a sealed container, and
qo, the viscosity before and after storage for 10 days was measured using a Mac Michael Viscosimeter.
It was measured by In addition, the dripping properties before and after storage at 40 qo for 10 hours were tested. These results are shown in Table-2. Note that these measurement methods are shown below. Measuring method for MacMichael viscosity: A composition whose temperature was adjusted to 20 qo was placed in a large cup attached to a MacMichael viscosimeter to prevent air bubbles from entering, and then a 1-diameter plunger connected to a spindle was poured into the composition. ．． Insert it up to 4 notches, rotate the cup with 2 plates PM, and take the reading after 1 sieve as the viscosity (OM).

The first wire belonging to the spindle is No. Assume that 18 wires are one. Measuring method for dripping property: A composition adjusted to a temperature of 20° is applied in the form of a right triangular bead with a base of 6 ribs and a height of 9 ribs on a glass plate set at an angle of 60° to the horizontal surface. Layer for a while and measure the distance traveled by the apex of the triangular bead.

At this time, the bead is applied in the horizontal direction at a rate of 7.6 seconds per second, with the vertical surface of the bead facing upward. Ryoryaku groove statement carp whip! Table 1 2 Viscosity and dripping examples of each blended composition 21
~24 Place 10 parts by weight of the polyurethane prepolymer obtained in the above example into a mixer purged with dry nitrogen gas, and mix with furnace thermal black, calcium carbonate, and diiso, which have been previously dried to a moisture content of 0.06% by weight or less. Decyl phthalate was added in the amounts shown in Taiichi 3 below, and the mixture was hermetically kneaded under reduced pressure.

Next, 1,2-di-n-butyl-stearyl trimellitate was added in the amounts shown in Table 3, and the mixture was hermetically kneaded under reduced pressure.
A composition of the present invention was obtained. This urethane composite was sealed in a closed container, and tested for McMichael viscosity and dripping properties before and after storage at 40° C. for 10 days in the same manner as in the previous example. The results are shown in Table 3. Table 3 As is clear from the above explanation, the polyurethane composition of the present invention can be produced by using a benzene cyclic carboxylic acid ester having an alkyl group having a specific number of carbon atoms and carbon black as a thixotropy improver. The disadvantages of performance modifiers are that the thickening effect is too large, the improving effect is essentially small, the effect wears off during storage, and the polyurethane prepolymer component thickens and gels. This has the advantage of improving points.

For reference, among the benzene cyclic carboxylic acid esters having the formula, the number of carbon atoms in R, the number of n,
The relationship between the carbon numbers of R' is shown in the attached drawing.

In addition, in the figure, the numbers on the right side of 0, △, ▲, mouth, etc. indicate the example numbers, and the numerals indicate reference examples, respectively.

[Brief explanation of the drawing]

The figure is an explanatory diagram showing in a graph the relationship between the number of carbon atoms in R, the number of n, and the number of carbon atoms in R' for the compounds shown in Examples among the benzene cyclic carboxylic acid esters used in the present invention. The number of carbon atoms in R' in the case of n21, (2,3).

Claims (1)

[Scope of Claims] 1. For 100 parts by weight of an isocyanate group-terminated polyurethane polymer, (1) 10 to 150 parts by weight of carbon black and (2) the following formula ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (In the formula, n is 0 to 3, R and R' are alkyl groups, R' has 1 to 8 carbon atoms, and R has carbon atoms of n
= 4 to 8 when n = 1 to 3, 4 to 18 when the number of carbon atoms in R' is 1, 9 to 18 when the number of carbon atoms in R' is 2 to 4, R 12 to 1 when the number of carbon atoms in ' is 5 to 8
A thixotropic polyurethane composition prepared by adding 1 to 150 parts by weight of a benzene cyclic carboxylic acid ester having the following formula: