US3600312A - Heat insulation material for insulated containers - Google Patents

Abstract

A HEAT INSULATING MATERIAL FOR THE WALLS OF FIRE-RESISTIVE SAFES, INSUALTED VAULT DOORS, AND INSUALTED RECORD CONTAINERS, INCLUDING WATER-IN-WAX CAPSULES IN CEMENT AND VERMICULITE CONTAINING COMPOSITIONS WHICH FORM THAT HEAT INSULATING FILLING MATERIAL FOR THE WALLS OF SUCH SAFES, VAULT DOORS OR CONTAINERS. THE ENCAPSULATED WATER PROVIDES AN INCREASED WATER CONTENT FOR THE INSULATING FILLING, WITHOUT INCREASING THE "FREE WATER" IN THE FILLING WHICH CAN LEAK FROM THE INSULATION AN INITIATE MOLD, ODOR AND RUST PROBLEMS, THEREBY INCREASING FIRE PROTECTION WHILE RETAINING FAVORABLE WEIGHT CHARACTERISTICS.

Description

United States Patent 3,600,312 HEAT INSULATION MATERIAL FOR INSULATED CONTAINERS Robert J. Bohland, North Canton, Ohio, assignor to Diebold, Incorporated, Canton, Ohio No Drawing. Filed May 26, 1969, Ser. No. 827,980 Int. Cl. C041) 43/00; C091: 3/28; A62c 3/00 U.S. Cl. 252-62 6 Claims ABSTRACT OF THE DISCLOSURE A heat insulating material for the walls of fire-resistive safes, insulated vault doors, and insulated record containers, including water-in-wax capsules in cement and vermiculite containing compositions which form the heat insulating filling material for the walls of such safes, vault doors or containers. The encapsulated water provides an increased water content for the insulating filling, without increasing the free water in the filling which can leak from the insulation and initiate mold, odor and rust problems, thereby increasing fire protection while retaining favorable weight characteristics.

BACKGROUND OF THE INVENTION Field of the invention The invention relates to heat insulating filling material for the walls of safes, vault doors, insulated files, and the like, and more particularly to improved insulation compositions having the favorable characteristics of prior cement and vermiculite containing compositions, and incorporate additional water mechanically bound to the compositions, which provide increased fire resistance as Well as Weight or thickness reduction for the insulated walls, or both.

Description of the prior art Prior insulating filling compositions for safes are described in Pats. Nos. 1,715,977 and 1,812,306. The amount of water available in such compositions which must be vaporized before the interior temperature can reach an unfavorable level determines the length of time that effective fireresistive properties are imparted to the insulated product. Unfortunately, when Water is increased to give additional fire protection, this increases the free water that can leak from the insulated product and can increase corrosion, mold, dampness and odor problems. Thus, an increase in the free water content of the filling to increase fire resistance increases these problems; and a decrease in the free water content as by using dry refractories has resulted in less satisfactory fire resistance.

Accordingly, increased fire resistance using prior insulation filling compositions requires increased insulated wall thickness, increasing the cost thereof and increasing the corrosion, mold, odor and dampness problems.

SUMMARY OF THE INVENTION Objectives of the invention include providing new heat insulating compositions for the walls of safes and the like which provide an additional water content for increasing the fire-resistive properties, with the additional water mechanically bound to the compositions so as to avoid any increase in corrosion, odor, mold and dampness problems; providing a new heat insulating composition which increases fire resistance without increasing wall thickness, or which enables fire resistance to be maintained at a desired level with reduced wall thickness, thus providing a lighter weight insulated product for any level of fire resistance characteristics; providing new heat ice insulation compositions eliminating an increase in free water; providing a new heat insulating composition which is relatively light in weight; and providing new heat insulating compositions for safes and the like which eliminate difiiculties heretofore encountered, achieve the stated objectives simply, elfectively and inexpensively, and solve problems and satisfy existing needs.

These objectives and advantages are obtained by the new insulation material compositions, the general nature of which may be stated as including in cement and vermiculite containing insulation materials, the inclusion 'of from 9% to 33% by weight of water contained in waterin-wax capsules in addition to Water otherwise present in the insulation material compositions.

DESCRIPTION OF PREFERRED EMBODIMENTS Percent Vermiculite 10.4 Portland cement 69.6 Water 20.0

Total 100.0

and may have a density of 0.49 gram per cubic centimeter.

A three inch thick wall filled with this insulation material composition when subjected to a typical fire test on one or the hot side, did not have a temperature change on the other or cold side until fifteen minutes had elapsed. The cold side temperature did not reach F. until forty minutes had elapsed. The cold side did not become heated beyond 212 F. (water boiling temperature) until a total time of two hours and fifteen minutes had elapsed; and it was some two hours and fifty-five minutes before all water in the insulation material had been vaporized and the maximum cold side temperature reached, which always must be below 350 F. in order to be given a fire test rating.

In accordance with the invention, encapsulated water, that is water-in-wax capsules, is added to this old or normal composition as the wet mix is being mixed in a mixer. This wet mix, as with prior insulations, is then poured into the wall cavity to be insulated. After setting, drying and curing for thirty days, the improved composition containing encapsulated water may comprise by weight:

Percent vermiculite 8.6 Porltand cement 57.6 Water 16.5 Water-in-wax capsules 17.3

3 identified as its 3M Bitem Brand water-inwax capsules, such as made in accordance with Pat. No. 3,423,489 dated Jan. 21, 1969.

The benefits derived from the added water mechanically bound in the form of water-in-wax capsules are many. A lower peak temperature results during the fire test, and the time required to reach approximately the boiling point of water is considerably extended, as is the time to reach peak temperature. The benefits of the added water contained in the capsules occur early in the fire test since the wax shells of the capsules rupture and melt as the temperature of 140 F. is approached. Some additional benefits are gained above 140 F. because of the requirements of heat of vaporization for the wax.

By the time that the 212 F. temperature is reached, little or no water is available from capsule for cooling the wall but the further available water after the encapsulated Water has been vaporized comes from that contained in the cement.

The amount of additional water mechanically bound in the composition added thereto as encapsulated water in accordance with the invention depends upon the degree of increased fire protection desired. It has been determined that from 5% to 30% by Weight of added water in the form of water-in-wax capsules may be added to the wet mix while being mixed without encountering any difficulties and while obtaining the added fire protection benefits sought.

Fire tests have shown that with the addition of about 30% water in the form of encapsulated water to the normal composition described, the time at ambient temperature is twenty-five minutes, the time interval to reach 190 F. is ninety-five minutes rather than forty minutes, the time of retaining a cold side temperature not beyond 212 F. is two hours and forty minutes, and the time to reach peak temperature (somewhat lower than the peak temperature reached by a composition not containing encapsulated water) is four hours and fifteen minutes.

This represents a gain in peak temperature time of one hour and twenty minutes. This outstanding and remarkable new result may be utilized in several different ways in the manufacture of safes and the like. The new composition may be used as in the last example (the one hour and twenty minute gain in peak temperature time) to obtain a diiferent and better fire rating for a given safe product without change in the structure of the safe; or its insulated wall thickness may be reduced (with a decrease in cost and weight) while retaining the same fire rating.

Furthermore, the increase in fire-resistive properties is achieved without any increase in free water in the insulation material present in the safe product, and thus problems of mold, odor, corrosion, etc., arising from the presence of free water are not increased even though substantial additional amounts of water are present in the composition for fire resistance.

An example of a heavy weight insulation compositon of the same general type comprises a mixture of an aggregate of vermiculite and diatomaceous earth, with portland cement and water which when mixed has a density of about 1.35 grams per cubic centimeter and after pouring, setting, curing and drying has a density of 1.041 g./cc. and has the following composition, by weight:

Percent Aggregate 18.2 Portland cement 54.5

Water 27. 8

In accordance with the invention, encapsulated water is added to this prior type heavyweight insulation and after mixing, pouring, setting, drying and curing for the required time has a composition by weight of:

Percent Aggregate 13.3 Portland cement 40.0 Water 20.0 Water-in-wax capsules 26.7

The cured composition has a density of 1.041 g./cc.

The 26.7% encapsulated water comprises 20% water and 6.7% wax so that the combined content of free and mechanically bound water available for fire-resistive prop erties in the cured heavy-weight insulation formula just given is 40%.

The heavyweight insulation material experiences benefits in fire-resistive characteristics similar to those described in respect of the lightweight insulation. A preferred range of addition of encapsulated water to the heavyweight composition is from 10% to 25% by weight of water in encapsulated form, added to the normal prior composition, as related to the material as cured.

The water-in-wax capsules have a nominal 3000 mi cron size which have a variation in capsule size of from 1.7 to 2.8 millimeters in diameter with a major portion of the capsules having a 1.8 to 2.4 millimeter diameter. It is preferred that the capsules have the range or variation in size for more efficient distribution in the insulation composition both as mixed and when setting, particularly in the lightweight insulation formula. The capsules range from to by weight of water and the balance wax shells in which the water is encapsulated.

Ranges of mechanically bound water in encapsulated form contained in the lightweight insulation have been indicated as being from 5% to 30% by weight Water and in the heavyweight insulation from 10% to 25% by weight water. Within these ranges it is preferred that the encapsulated water in the lightweight composition be between 20% and 30% by weight and in the heavyweight composition, between 15% and 20% by weight.

The new lightweight insulation composition of the invention with the same water content as in prior lightweight compositions not containing encapsulated water, results in a 43% reduction in thickness of the insulated wall and a 31% reduction in weight to obtain the same fireresistive properties. To achieve the same water content in the improved heavyweight insulation, a 32% reduction in thickness and a similar 32% reduction in weight is involved with the same fire-resistive properties.

However, where increased fire-resistive properties are desired, for instance to obtain an increased fire rating for a standard product Without structural change of the prod uct, such results may be obtained by using the improved compositions of the present invention wherein the additional encapsulated water provides the increased fire-resistive properties.

It is recognized that the inclusion of encapsulated water as a material in prior insulation compositions involves an added cost. However, the benefits achieved in increased fire-resistive properties, or reduction in weight or thickness of the insulated product, or avoidance of any increase in mold, corrosion, etc. problems where increased fire protection is achieved, will more than compensate for the added cost.

Accordingly, the new insulation compositions of the present invention provide increased fire-resistive properties for products in which the improved insulation is used, provide compositions which are easy to manufacture, and solve problems and satisfy the objectives described.

In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art because such terms are used for descriptive purposes and are intended to be broadly construed.

Moreover, the description of the invention is by way of example and the scope of the invention is not limited to the exact details described since the amount of encapsulated water present in any insulation composition may be varied in accordance with the degree of additional fire protection desired.

Having now described the features, discoveries and principles of the invention, the manner in which the improved compositions are made and used, the characteristics of the new compositions and of products insulated thereby, and the advantageous, new and useful results obtained; the new and useful compositions are set forth in the appended claims.

I claim:

1. In a heat insulation material cement and vermiculite containing composition for insulated containers, the combination of additional water mechanically bound to the composition in the form of water-in-wax capsules, foam concentrate in the composition in initial wet mix form before curing, and the mechanically bound water in the form of water-in-wax capsules comprising 5% to 30% by weight of the cured composition.

2. In a heat insulation material cement and vermiculite containing composition for insulated containers, the combination of additional water mechanically bound to the composition in the form of water-in-wax capsules, foam concentrate in the composition in initial wet mix form before curing, and the mechanically bound water in the form of water-in-wax capsules comprising 20% to 30% by weight of the cured composition.

3. In a heat insulation material cement and vermiculite containing composition for insulated containers, the combination of additional water mechanically bound to the composition in the form of water-in-wax capsules, the vermiculite being contained in an aggregate of vermiculite and diatomaceous earth, and the mechanically bound water in the form of water-in-Wax capsules comprising to 25% by weight of the cured composition.

4. In a heat insulation material cement and vermiculite containing composition for insulated containers, the combination of additional water mechanically 'bound to the composition in the form of water-in-wax capsules, the ver- 6 miculite being contained in an aggregate of vermiculite and diatomaceous earth, and the mechanically bound water in the form of water-in-Wax capsules comprising 15% to 20% by weight of the cured composition.

5. A heat insulation material composition for insulated containers comprising by weight as cured:

Percent Vermiculite 8.6 Portland cement 57.6 Water 16.5 Water-in-wax capsules 17.3

and having a dry density of 0.59 gram per cubic centimeter.

6. A heat insulation material composition for insulated containers comprising by weight as cured:

Percent Aggregate of vermiculite and diatomaceous earth 13.3 Portland cement 40.0 Water 20.0 Water-in-wax capsules 26.7

and having a dry density of 1.041 g./cc.

References Cited UNITED STATES PATENTS 2,448,280 8/ 1948 Sargent et al. 25262 2,449,253 9/ 1948 Sargent 25262X 3,016,308 l/1962 Macaulay 252316X 3,103,254 9/1963 Stedman 25262X 3,212,896 10/1965 Yudelson et al. 252316X 3,336,155 8/1967 Rowe 252316X 3,372,040 3/1968 Ware 2528.1X 1,715,977 6/1929 Bates 106-86 1,812,306 6/1931 Russ 106-86 3,317,433 5/ 1967 Eichel 2527X HAROLD ANSHER, Primary Examiner U.S. Cl. X.R.