FI62039B - FRAMEWORK FOR THE FRAMEWORK OF THE FRAMEWORK FOR THE IMPLEMENTATION OF THE FRAMEWORK - Google Patents

Description

f.l NOTICE OF PUBLICATION /, (110

Jua mm, UTi * eeNiN0ssKmFT 62 0 39 ¢ (45) Patent granted 10 11 1982 LraavO Patent meddelat (S1) K ».ik? /Intel.3 c 01 B 17/00, C 04- B 21/02 FINLAND —FINLAND (21) P »wnttlh« k * mii · —tamtamMcnlnf 257 * + / 73 (22) HakemlspUva — AiMaknlngid * 16.0Ö.73 "'(23) Alkupilvt — Glltl | h« t »d« j 16.08.73 (41) ) Tuthit lutkiMkil —Bllvlt offamHf ηο,

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Patent- och registaratyralMO V 1 An ^ kan utli | d oeh utl. * Krlft * n publlcmd 30.07.82 (32) (33) (31) Pyydtey • Tuoikeu.-enird »rioriMt 17.08.72 25.07.73 USA (US) 281587, 382598 (71) Chevron Research Company,. 200 Bush Street, San Francisco,

California 9 ^ 104, USA (72) John Mitchell Dale, San Antonio, Texas, Allen Clarence Ludwig,

San Antonio, Texas, USA (US) (7 * 0 Oy Kolster Ab (5 **) Method for the production of sulfur foam and equipment used in the method - Förfarande för framställning av svavelskum och anordning account användning vid förfarandet

The invention relates to a process for preparing sulfur foam by heating a sulfur-containing mixture containing at least 50 parts by weight of sulfur to a temperature above the melting point of the mixture by adding a gas-forming two-component blowing agent, foaming the mixture and settling the foamed sulfur mass to the desired location.

The invention also relates to a device for use in the method.

U.S. Patent 3,337,355 discloses a process for making sulfur foams, which generally involves heating elemental sulfur above its melting point, mixing the stabilizer and viscosity enhancer with the molten sulfur, and forming bubbles in the molten sulfur and cooling below the melting point. Bubble formation is accomplished by introducing a blowing agent such as a mixture of phosphoric acid and sodium carbonate or an organic substance such as N, N'-dinitrospentamethylenetetramine (Η, Ν'-dinitrosopentamethylene tetramethylene) into a sulfur containing a viscosity enhancer and a stabilizer. In a typical production method, the blowing agent is introduced into the modified molten sulfur in a vessel and the resulting foam is passed from the vessel through a line and placed in the desired location.

2 62039

Although this method of forming sulfur foam may be suitable for batch applications and applications where mobile equipment is not important, in certain applications where the process is desired and / or the equipment is movably mounted to accommodate a continuous layer of foam from, for example, a continuously moving vehicle, that the mixing of the sulfur and viscosity improver and the stabilizer is separated from the addition of the blowing agent.

It is also desirable to apply a continuous process to the preparation of other sulfur-based foams, such as those described in U.S. Patent Applications 253 1 H and 3 696, which use mixtures of sulfur and ring hydroxy- or ring-amino-substituted aromatic polysulfides as base foams. The mixtures are foamed and crosslinked (crosslinked) by the addition of an organic acid, preferably a carboxylic acid and a polyisocyanate or polyisothiocyanate. Because the aromatic polysulfide contains hydroxy or amino groups that react with isocyanates, prior addition of the acid to the molten sulfur-aromatic polysulfide di mixture is necessary. In addition, in many cases the acids used are linked to polysulfide chains and when polyisocyanate is added, the reaction produces CO polyisothiocyanates) causing foam formation, and the reaction of the carboxyl and isocyanate groups provides additional polymer crosslinks with amide formation (in addition to the formation of urethane or ureido with the hydroxyl and amino groups of the polysulfide).

The present invention provides a process for the continuous production of sulfur-based foams. The process according to the invention is characterized in that (a) the sulfur-containing mixture together with a small amount of the first blowing agent component is heated to 100-150 ° C in the first zone, (b) the mixture is passed under liquid at this temperature to the second zone, (o) the mixture is stirred in the second zone. with a second blowing agent component which, together with the first component, releases gas and foams the mixture, and (d) the foamed mixture is taken out of the second zone at a rate such that the average residence time of the mixture in the second zone is 0.1 to 3.0 seconds.

The short time at ambient temperature causes the foam to solidify into a rigid, stable building material. Thus, it can be placed in building molds or, for example, directly on the roofs of dwellings or other similar structures to form insulation or on the hulls of boats (ships) to provide buoyancy or for other similar uses.

In one embodiment of the invention, the molten sulfur composition is passed from the first zone through an outlet line to a second zone (dynamic mixer) in which the blowing agent is rapidly treated by dynamic means such as mechanical power stirring, shaking, vibration with an inert gas such as nitrogen, etc. and the resulting foam is removed for placement at the desired location.

In another embodiment, the molten sulfur composition is passed from the first zone to a second zone comprising a static mixer into which the blowing agent is introduced and in which the permeable substance is completely mixed for foaming by the action of stationary turntables.

The gas generating components used with the types of materials described in U.S. Patent 3,337,355 »are inorganic sulfides, usually metal sulfides. These include alkali metal sulfides (group Ia) such as lithium sulfide, sodium sulfide, potassium sulfide, alkaline earth metal sulfides (group Ha) such as magnesium sulfide, calcium sulfide, strontium sulfide, barium sulfide. Group Hb sulfides include zinc sulfide, group lila sulfides include borosulfide, aluminum sulfide, scandium sulfide, etc., transition metal sulfides include mangarese sulfide, iron sulfides, cobalt sulfide, etc., and Group Vb sulfides include phosphorus sulfides, arsenic sulfides, and arsenic sulfides, arsenic sulfides, Phosphorus sulfides can be produced in situ by introducing elemental phosphorus into the molten composition. Various other sulfides can be produced in this way. Sulfides are included in the composition at about 0.1-2.0 moles per 100 moles of sulfur.

The blowing agents used in the process of U.S. Patent No. 5,337,355 are proton donors, which include those capable of donating a proton or protons under second zone reaction conditions, i. at 100-150 ° C to react with sulfides to form HgS. Examples of suitable proton donors include conventional inorganic protic acids such as phosphoric acid, phosphoric acid, hydrochloric acid, sulfuric acid, nitric acid, etc. Organic protic acids such as formic acid, acetic acid, propionic acid, benzoic acid, etc., etc. , phenol and alcohols, etc. For many gas-producing sulfides, the acid potency of the proton donor should be at least equal to that of water and usually such that the pH of a 1 molar aqueous solution is 3 or less.

For other sulfides such as boron sulfide, aluminum sulfide, phosphorus sulfide, etc., water, preferably introduced in vapor form, is the preferred blowing agent due to its low cost and efficiency.

The amount of blowing agent used is sufficient to produce protons in an amount that allows the sulfur of the gas-producing sulfide component to be converted to hydrogen sulfide, preferably at least a stoichiometric amount relative to the sulfide. Steam is a preferred blowing agent. I steam especially with P „S, -

2 D

62039 4 The hydrogen sulfide that produces it produces a particularly smooth, fine-grained foam.

The blowing agents used in the production of foams from mixtures of sulfur and aromatic polysulphides are polyisocyanates or polyisothiocyanates of the formula R (NCX) n, where R is an unvalent organic radical, X is chalcogen with a molecular weight of less than 33 and n is integer, at least 2. The gas formed in the case of these blowing agents is COg or COS. These substances are used in an amount (i.e., added to the molten composition in the second zone) that a sufficient number of isocyanate groups (or isothiocyanate groups) are present to react with at least $ 10, and preferably $ 50 and · preferably about $ 100 sn. acid groups present.

In addition, it is preferred that sufficient isocyanate groups be provided to react with other functional groups that may be present, including amino and hydroxyl groups.

The foam stabilizing additive combinations used vary depending on the basic type of foam thus produced. In the case of foams disclosed in U.S. Pat. No. 3,337,355, foam stabilizers are those described in the patent as viscosity enhancers or stabilizers. Viscosity enhancers are added, which are explained as substances which, when added to molten sulfur, increase the viscosity of the sulfur below the transition temperature. These substances include phosphorus, arsenic, antimony and phosphorus sulfides. It should be noted that these agents operate in two ways in the process of this invention, providing foam stabilization as well as gas formation for foaming when contacted with the proton donor. Another group of substances can be used that tend to increase the viscosity of sulfur below its normal transition temperature, but eliminate most of the increase in viscosity above the normal transition temperature. These materials include styrene monomer, ethylene disulfide, polysulfide rubbers such as "Thiokols". Another substance which is mixed with sulfur to produce a foam precursor is described in said patent as a "stabilizer". These substances are finely divided inert substances with private particles having a plate-like shape. Examples of these substances are ground mica, aluminum pigment, grades with plate-like particles such as kaolin or porcelain clay, talc with plate-shaped particles, etc. These substances are called plate-like stabilizers. These substances may optionally be included in aromatic polysulfide-based foams.

In the production of foams based on a mixture of sulfur and aromatic polysulfide, the foaming agents are those described in U.S. Patent Application 344,694, the contents of which are incorporated herein by reference. They include compounds represented by the following types of acid compounds: 5 62039 (1) acids of the formula

/ RIY

B

Xb2y 0 0 0

tl ^ M

wherein Y is -C-OJ, -S-OJ; -P-OJ

«F

0 OH

wherein J is H or alkyl of 1 to 6 carbon atoms; 0

If

-POOF

t

L

wherein L is H, a hydrocarbon having 1 to 18 carbon atoms (Hydrocarbyl) or the same as the second group attached directly to the phosphorus atom by a carbon-phosphorus bond; -B-OH where J is as defined above, or -B-OH where Q is H, 1-18 carbon atoms 1

OJ Q

hydrocarbon or is the same as another group attached directly to the boron atom by a carbon-boron bond; R 1 and R 8 are divalent hydrocarbon radicals having 1 to 18 carbon atoms which may be replaced by up to two halohydroxyl or mercapto groups per radical and may contain 1 to 5 vinylene or ethylene groups per radical, M is O, Sf or (CH 2) f , f is an integer from 1 to 10 and the sum of carbon atoms in R 1 and R 8 is 2 to 18.

(2) acids of the formula

r5_Ch —fCH2> m-Y

z wherein Y is as described above, R 1 is a hydrocarbon radical of 1 to 18 carbon atoms, up to two of which may be replaced by halogen, hydroxyl or mercapto groups and may contain 1 to 3 vinylene or ethylene groups, Z is hydroxy, halogen. the dainercapto group or H, when m is greater than 0, is an integer from 0 to 18 and the sum of the carbon atoms in Rz and (CH0) is 1 to 19 · (3) 2-3 units of the addition oligomers of the unsaturated acids of (2) .

(4) unsaturated acids of formula

R, -CH = C-Y

'I

B3 wherein Rj and Y are as defined above.

(5) 2-5 units of the acid addition oligomers of (4).

(6) heterocyclic acids of the formula? 4 R, -CH-CH- (CHO) -CH-R.

4, 2'p, 4

S-S

6 62039 wherein R 1 is H, Y is an aliphatic hydrocarbon radical having 1 to 10 carbon atoms as defined above or an aliphatic hydrocarbon radical having 1 to 10 carbon atoms substituted with an acidic group Y as defined above, wherein at least one R 1 is a carboxy radical or a substituted aliphatic hydrocarbon radical. radical and where p is 1 or 2.

(7) partially esterified polybasic acids which may contain a hydroxy, mercapto, carboxy, vinylene or ethylene group and which have an acid equivalent weight (molecular weight divided by the number of free acid groups) in the range of about 100 to 1,000.

(θ) acids of formula Y

f

A

y-D-C-Z

f

B

•

Y

where Y is as defined above, A, B and D are independent C H (R ..) (R, J,

il Q1 XX P Xc Q

n is an integer 0T5, p is an integer 0-2, q is an integer 0-1, R 1 is alkyl of 1-4 carbon atoms, Z is H, OH or SH, m is an integer equal to or less than 2n-pq, R 2 is OS or SH and in at least 2 of A, B and D n is equal to or greater than 1.

(9) acids having the formula R 1 Y, wherein Y is as defined above and R 1 is a hydrocarbon group having 3 to 24 carbon atoms, wherein Y is attached to R 2 with an alicyclic group having 3 to 12 carbon atoms.

(10) acids of the formula wherein Y is as defined above, R 1 is SH, an aliphatic hydrocarbon radical of 2 to 24 carbon atoms or a cycloaliphatic hydrocarbon radical of 5 to 20 carbon atoms and v is an integer of 1 to 5 *

The acids are used in an amount of about 0.002 to 0.50 acid equivalents per 100 g of sulfur composition.

Examples of preferred acids are the various types of carboxyl-containing substances described above, including dicarboxylic acids such as glutarazeline, etc., thiodipropion, thiobutane, etc., and dithioic acids, such as dithiodiglycolic, dithiopropionic acids, etc.

Examples of unsaturated acids are alkanoic acids such as acrylic, propatgyl crotonic acid, etc. Type 2 acids include chloroacetic, α-chloropropionic, glycolic, lactic, α-mercaptoacetic, mercaptovaleric acid, etc.

7 620 o 9

Examples of type 4 acids having a cyclic dithio structure include 1,2-dithiolane-4-carboxylic acid, 6,8-thionic acid (thioctic aoid), and the like.

Aromatic precursors such as phenol or aniline can be mixed and reacted directly with elemental sulfur to form an aromatic polysulfide. The reaction time is generally about 1 to 24 hours, preferably about 4 to 12 hours. The reaction temperature is above about 120 ° C, generally in the range of about 120-200 ° C, with at least 2 moles of sulfur being used for each mole of the substituted aromatic compound in the leaf. However, although in situ preparation is possible, it is generally preferred that the polysulfide be prepared separately and simply mixed with molten elemental sulfur either in the first (molten) zone or prior to introduction into the first zone.

In summary, foam stabilizers, viscosity enhancers, polysulfide or organic acid stabilizers, etc. in sulfur are introduced into the first (molten) zone, which may be a cauldron or the like, equipped with stirring and heating means. As already mentioned above, the substances can either be melted in this zone or they can be introduced in a premixed molten state. This vessel may be pressurized or open and the molten mixture is then passed by pressure, gravity or mechanical means such as a pump, etc. through a suitable line, either heated or insulated or both, to another (mixing) zone, which may be a static mixer or a power mixer. with used wings. The blowing agent is preferably introduced into the line before the mixture enters the mixing zone. Since the mixture is normally fed to the second (mixing) zone under pressure, it is necessary to introduce the blowing agent into the line at least as high a pressure and preferably under a higher pressure than the molten sulfur. A preferred means of ensuring that the molten mixture enters the mixing zone under the correct pressure is to introduce an inert gas, i. a substantially inert gas for molten sulfur (e.g., air, nitrogen, etc.) under a pressure equal to or greater than the pressure of the mixture at a point prior to the point where the mixture enters the second mixing zone. After the foam has passed through the second mixing zone, it is placed on the desired surface, usually without delay, to maintain fluidity.

Although not necessary to understand the invention, the accompanying Figure 1 illustrates a typical embodiment of the process of the present invention. The sulfur-containing composition is introduced into the first (molten) zone 1. The composition is heated until a temperature of 100-150 ° C is reached. This temperature should be sufficient to ensure that the composition is in liquid form. The mixture is then passed through line 2, where the composition is kept in liquid form, to the second (mixing) zone 3 · The blowing agent is introduced into the second zone 3 via line 4. The gas-containing effluent 8 62035 is discharged from the second (mixing) zone 3 after the correct residence time and allowed to cool.

A preferred embodiment of the apparatus for making the sulfur foams of the present invention is illustrated in Figure 2. The first vessel 10 is provided with heating means 11 which may have a temperature adjustable electric heating arrangement controllable to melt the sulfur-containing composition introduced into the vessel via line 12 and to keep the composition in a liquid molten form. The purpose of the guide means 13 is to allow the transfer of the liquid composition from the first vessel 10 to the second vessel 1.

Pressure generating means, such as a pump 15, are used to cause the liquefied composition to pass through the conduit means 13 and flow control means, exemplified by the metering valve 16, are used to monitor the flow of the heated liquefied composition through the line 13 to the second vessel li. The apparatus is provided with means for keeping the composition in a molten state in a vessel li. Such means may be, for example, a thermal insulation coating 17. The second vessel is provided with mixing means, which may be, for example, an electric impeller 18, for thoroughly mixing the composition with the blowing agent. The apparatus is provided with a tank 19 for storing the blowing agent and the tank is connected to the container il by a second line 20.

Connected to the line 20 are means 21 for monitoring the flow of foaming agent from the container to the second vessel li.

Removal means, such as line 22, is provided in the apparatus for removing the mixture of heated and liquefied composition and blowing agent from the second vessel to an environment where the temperature is below the melting point of the mixture, allowing the mixture to cure into a solid cellular hazardous material.

The following examples illustrate the invention.

Example 1

Preparation of sulfur foam with a blender H „P0, 15 kg portion of elemental sulfur, 1.5 kg of talc (Mistron Vapor AJ, 0.1 kg and 113 g of tricresyl phosphate) were placed in a vessel equipped with a power stirrer and a pressure-tight lid. The mixture was heated with stirring 155 C, 2.5 kg / cm pressure was introduced into the vessel, forcing the molten mixture through the outlet line to the blender. Phosphoric acid (foam) was forced into the inlet line of the rotary flowmeter at 3.9 kg / cm at a rate measured with a flowmeter such that about 3- 5% by weight of acid was mixed into the molten mixture, the foam was removed from the blender nozzle and cooled to form a rigid substance with smooth small cells, and the amount of acid addition caused the foam density to vary between 199 and 336 kg / m 3.

9,6203;

Example 2

Preparation of sulfur foam with a static mixer.

Using the general procedure and apparatus mentioned in Example 1, with the exception that a 2.54 cm diameter static mixer was used as the second zone mixer, 227 kg of sulfur, 25 kg of talc, 11 kg of PS, 2 5 7 kg of 1.5 cyclooctadiene and 0.6 kg tricresyl phosphate was mixed and at a vessel pressure of 2.8 kg / cm the mixture was forced through a static mixer together with phosphoric acid. The flotation unit was mounted on wheels and moved and a uniform layer of foam was placed on the ground with a nozzle, where it had a density and a solidification of about 240 kg / m 2.

Example 5

Preparation of foam using water as a blowing agent.

The general procedure of Example 1 was followed by replacing phosphoric acid with water as a blowing agent. A foam with uniformly small cells and a density of 117 kg / m 5 was obtained.

Example 4

Preparation of foam using steam as a blowing agent.

However, the general procedure of Example 2 for preparing the foam was followed using steam as the blowing agent. The steam was sprayed at such a rate that optimal foaming was observed, i. steady flow and small cell size. The density of the foam produced was 192 kg / m 2.

Example 5

Preparation of foam from a mixture of aromatic polysulphide and sulfur. 1 part by weight of phenol and 4 parts of sulfur were placed in a reaction vessel equipped with a heater and a mechanical stirrer. The mixture was heated to 150-160 ° C for about 12 hours. The product was removed from the vessel and allowed to cool to form an amorphous solid.

B. 12.7 kg of the product of A and 25 kg of sulfur were placed in the reaction vessel described in Example 1 and then heated to about 145 ° C. To the mixture was added 0.50 g PS. and the temperature was allowed to rise to 160 ° C for about 2 hours. 1.7 kg of dithiodipropionic acid were added to the mixture, which was allowed to stir for another 1.5 hours at 150-160 ° C. 2 kg of talc (Mistron Vapor Λ) was added to the mixture and the temperature was dropped to about 145 ° C. 0.2 kg of Dow-Coming PC-193 silicone surfactant was added to the mixture and the as-Tian pressure was raised to about 2.5 kg / cm. The apparatus was equipped as in Example 1. When the molten mixture arrived in the blender, it was mixed with diphenyl methane diisocyanate, which was forced into the mixer from the tank under pressure through a rotary flow meter. The diisocyanate addition was adjusted with a flow meter to produce approximately equimolar amounts of isocyanate groups relative to the carboxyl groups present in the sulfur mixture in a single mixer. The foaming effluent from the mixer was placed on the ground and allowed to cool, yielding a rigid substance with a density of about 160 kg / m 2 10 620 39

Example 6

Preparation of foam from a mixture of aromatic polysulphide and sulfur with a static mixer.

The procedure of Example 1 was followed in detail with the exception that the static mixer used in Example 2 2 was used instead of the power mixer. Compressed air at a pressure of 4> 2 kg / cm was introduced into the transmission line at a point just “upstream” from the point where the diisocyanate addition line was attached.The cooled foam produced, when cooled, was a strong, rigid material with a density of about 160 kg / m 2.

The process of this invention can be advantageously used in many applications where the portability of the production unit is important. Thus, the production equipment can be mounted on legs or on the chassis of a truck (truck) and moved to the construction site. Hoses »tubes or other means for transferring the mixture from the first reaction zone to the second mixing zone may be of the desired quality» so that maximum comfort and portability can be achieved. If the length of the means of transport (pipe hoses, etc.) is large, it may be necessary to use insulating or heating means, or in some cases both, in the means of transport to keep the sulfur-based mixture hand in molten form. Thus, the only limiting factors for distance are insulation and thermal requirements and power requirements for pumping the substance to another zone.

The process can thus be easily used to form foam insulation for rack constructions, whereby the first zone (i.e. the mixing tank) can be mounted on the vehicle at street level and the mixture can be pumped through a tank and pipes of correct strength to the top of large buildings where the user can place insulation.

Although the process and apparatus of the invention have been described as enabling continuous foam formation as opposed to single zone processes, interruptions in foam formation often occur as necessary or desirable. These cases occur, for example, when molds need to be filled with foam and when one mold is filled, it is desired to transfer the foam discharge to another mold. It will be appreciated that this can easily be accomplished by using valves and recirculation lines for both sulfur compositions and foaming agents. Such arrangements allow for easy interruption in foam production while maintaining the necessary temperature control and the ratio of blowing agent to sulfur preference. Returning the recirculation to the mixer immediately begins foam production.

Although the nature of the present invention has been explained in detail by several examples, this has been done for illustrative purposes only without limiting the invention. It will be apparent to those skilled in the art that modifications and changes may be made in the practice of the invention within the scope of the invention as defined in the appended claims.

Claims (4)

A process for preparing sulfur foam by heating a sulfur-containing mixture containing at least 50% by weight of sulfur to a temperature above the melting point of the mixture by adding a gaseous two-component blowing agent, foaming the mixture and settling the foamed sulfur mass to the desired location, characterized in that (a) together with a small amount of the first blowing agent component is heated to 100-150 ° C in the first zone, (h) the mixture is passed in a fluid state at this temperature to the second zone, (c) the mixture is mixed in the second zone with the second blowing agent component, which together with the first with releasing gas and foaming the mixture, and (d) taking the foamed mixture out of the second zone at a rate such that the average residence time of the mixture in the second zone is 0.1 to 3.0 seconds; Process according to Claim 1, characterized in that an inorganic sulphide, preferably phosphorus pentasulphide, is used as the maximum blowing agent component and a proton donor, preferably water vapor, is used as the second blowing agent component. >. Process according to Claim 1, characterized in that an organic acid, preferably acrylic acid, is used as the first blowing agent component and a polyisocyanate or polyisothiocyanate, preferably diphenylmethane diisocyanate, is used as the second blowing agent component. Apparatus for carrying out the method according to claims 1 to 3, characterized in that it comprises a first vessel (10) provided with a heating device (Li) into which the sulfur-containing mixture is fed, the heating device (Li) being adjusted so that the mixture remains in the first vessel (10). ) means (lj) for maintaining the molten state in the pipeline (13), a means (20) for maintaining the molten state in the pipeline (13), a second vessel (13) with a stirrer (18), a connecting pipeline (13) between the first and second vessels, ) for introducing a second blowing agent component into the second vessel (li) and a device (21) for controlling the rate of inlet flow to the second vessel (il) of the second blowing agent component. Device according to claim 1, characterized in that the first vessel (10) is provided with a stirrer.