CA1037015A

CA1037015A - Process for improving the wettability of natural or synthetic zeolites

Info

Publication number: CA1037015A
Application number: CA212,804A
Authority: CA
Inventors: Heinz Haschke; Gerhard Morlock
Original assignee: Henkel AG and Co KGaA; Deutsche Gold und Silber Scheideanstalt
Current assignee: Henkel AG and Co KGaA; Evonik Operations GmbH
Priority date: 1973-10-31
Filing date: 1974-10-31
Publication date: 1978-08-22
Also published as: JPS5074600A; DE2354432C3; DE2354432A1; ATA877274A; GB1436077A; FR2249835A1; BE821708A; FR2249835B1; JPS5545487B2; AT339259B; DE2354432B2; IT1021985B; NL177304C; NL7412021A; US3962132A

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention provides a process for improving the wettability of natural or synthetic zeolites, which comprises treating said zeolites with thorough mixing with an aqueous sol-ution of at least one polycarboxylic compound selected from a polyelectrolyte polycarboxylic acid and a completely or partially neutralized polycarboxylate containing at least 40 primary mole percent of carboxyl or carboxylate groups and having an average degree of polymerization (numerical average) between 3 and 5000 at a temperature between 0 and 100°C for at least five minutes, the aqueous solution being used in a concentration between approximately 2 and approximately 800 g of polycarboxylic com-pound per litre and in an amount to provide approximately 0.01 to 10 parts by weight of polycarboxylic compound per part by weight of zeolite, the hydrophillic zeolite so obtained when required being either dried or separated from the aqueous phase.

Description

~lD37~
The present invention relates to a process for im-proving the wettability of natural or synthetic zeolites by water.
In an application which has an older priority but is not a prior publication it was proposed to use cation-exchanging sodium aluminium silicates oE the zeolite type as phosphate substitutes for washing and cleaning as well as in washing and cleaning agents. However, the replacement of the phosphates by zeolites results in poor wettability of these agents by water is against the use of zeolites in relatively large proportions of the total mixture. For example, if the condensed phosphates, such as particularly pentasodium triphosphate (="sodium tripolyphosphate") which serve as builders in conventional washing and cleaning agents, are completely replaced, this negative effect shows plainly upon sprinkling the agents on water or putting them into water where they remain unwetted for a relatively lengthy period of time and possibly float on the water surface ("sawdust effect"). This results in a delayed ~ -efficiency of these washing and cleaning agents i.e., particu-larly when using them in automatic washing machines the totaltime available for the washing cycle is not utilized, which causes an apparent decrease in the washing performance of the agents. Further, because of the "sawdust effect" certain components of the washing and cleaning agents based on zeolite may be lost in the washing process being deposited on the inter~
~;~; ; faces wash liquor-air wash liquor container walls. Therefore, ;
in order to be able to better utilize the known power of the zeolites to bond Ca2+ and Mg2+ ions for the building of washing .
and cleaning agents low in phosphate or free from phosphate, an improvement in their wettability by water, i.e., to render them hydrophilio is desirable.

- -. ,-.

~L~370il ~i A process for improviny the wettability of natural or synthetic zeolites has now been found T~hich comprises treating said zeolites with an aqueous solution of at least one polycar-boxylic compound selected from a polyelectrolytic polycarbox~lic acid and completely or partially neutralized polycarboxylate containing at least 40 primary mole percent of carboxyl or carboxylate groups and having an average degree of pol~nerization (nummerical average) between 3 and 5000 at temperatures between 0 and 100C for at least five minutes while mixing thoroughly and when required, separating or drying the hydrophilic zeolites from the aqueous phase, the aqueous solution being used in a concentration between approximately 2 and approximately 800 g of polycarboxylic acid or polycarboxylate per litre and in an amount to provide approximately 0.01 to lO parts by weight of polycarboxylic compound per part by weight of zeolite.
When the process the hydrophillic zeolites are dried ~
directly from the aqueous phase (without any previous separation), ~ i then the charging of the zeolites with the polycarboxylates can also be carried at values of the wieght ratio of polycar-:,, boxylate~ zeolite, i.e., at values which are substantially ~-above the adsorption/desorption equilibrium concerned. For this . :
purpose spray drying is particularly preferred as the drying process. ;
.~-An adsorption/desorption state in which the zeolite is charged with at least l part by weight, preferably at least 3 ~ -parts by weight, particularly 5 parts by weight of polycarboxy-.
late per lO0 parts of weight of zeolite can be regarded as ade- -~
:.. .:
quate in the process according to the invention. The charge fac*or of a zeolite thus rendered hydrophilic can be determined 30. by measuring the loss on ignition after drying the zeolite. ~--.. . . - ..;

- 2 - ;
~ . ' :~`' ' .

1~3~1L5 The charging of the zeolites with polycarbo~.ylates which is carried out by means o~ the process according to the invention in order to render the zeolites hydrophilic can be carried on suitably to max;imum charges of 200 parts by wei~ht, preferably 100 parts by weight, particularly 50 part~ by weight of polycarboxylate per 100 parts by weight of zeolite.
The process according to the invention can be applied to any natural or synthetic aluminosilicate of the zeolite type.
These compounds are described in greater detail in R.F. Gould "Molecular Sieve Zeolites-I", Advances in Chemistry Series 101, American Chemical Society, Washington, D.C., 1971. Particularly important representatives are the zeolites of the so~called A type, i.e., synthetic zeiolites of the Na-Al-silicate type having the formal chemical formula (idealized): Nal2 [(A102)~12 (sio2)~l2];x H20 or written in a different way: Na20 : A1203 :
SiO2 ~ 2 with A102 : SiO2 ratios of about 12:12, i.e., pre-cisely expressed between 1:0.5 and 1:2.5, particularly between 1:0.8 and 1:105 (see R.F. Gould, loc. cit., page 10 and 12 as well as 22 and 23). The Na20 : SiO2 ratios of these zeolites are ~ ~-approximately between 0.2 and 2.0 (see German Patent 1 038 017).
When subjecting the zeolites to the treatment according to the process of the invention they are suitably in the form of powder, i.e., with avexage particle diameters between approxi-mately 0.1 and 100, preferably between 1 and 20, particularly ~ ~
between 1 and lO~mO It is clear that the establishment of an - -adequate adsorption/desorption state, which can be extend to a ~ - :
complete adsorption/desorption equilibrium, is promoted by proper mixing. Therefore, the treatment is suitably carried out x ~ in a mixer while stirring vigorously or in a spray mixer.
The synthetic zeolites can be subjected to the treat-ment according to the process of the invention even without

- 3 -' 31037(~L5 previous isolation, i.e., in the form of a suspension in the mother liquor of their procluction.
, The treatment is carried o~ ~Lth the aqueous isolution of at leaist one member selected from a polyelectric polyc æboxylic acid and a campletely or partially neutralized polycarboxylate. The content of carboxyl or carbo~yl-ate groups m the polycarboxylic acid or polycarboxylate must be at least 40, preferably at least 50, particularly at least 60 primary mole percent. 'L~e average degree of polymerization (numerical average) of the polyelectrolyte must be between 3 and 5000, preferably between 3 and 300, particularly between 3 and 100.
In general the treatment can be successfully carried out at temp-eratures between 0 and 100, preferably between 15 and 95, particularly between 20 and 50C.
An adequate adsorption/desorption state between the zeolites and the aqueous polyelectrolyte solution is obtained within a relatively short period. ~lerefore, the treatment accorcling to the process of the invention usually requires a munimum of time, i.e., from approximately 5 to approximately 30 minutes, until the aqueous phase can be separated or until the entire ~ ;
suspension can be dried.
~le aqueous polyelectrolyte solution is appliecl in concentrations - -between 2 and approximately 800, preferably between 5 and 500, particularly betweeen 15 and 400 g per litre and is used in such amounts that the poly-electrolyte content is approximately 0.01 to 10, preferably 0.03 to 2, par-ticularly 0.05 to 1 part by weight per part by weight of zeolite.
The amount of polyelectrolyte adsorbed by the zeolite in the treatment according to the process of the invention depends of course to ; ~`
some extent on its composition, particularly on its content of carboxyl or car~oxylate groups, that is to say, the higher the content of carboxyl or carkoxylate groups the greater will be the amount of polyelectolyte adsorbed. `~
The zeolite usually adsorbs a maximum of approximately 5 to approximately 25 parts by weight of polyelectrolyte Fer 100 parts by weight of zeolite, the .~ , .

- 4 -~37~ S
concentration of the polyelectrolyte solution being only of minor importance.
All the polycarboxylic acids and their complete and partial salts with an alkali metal or with ammonia are suitable as polyelectrolytes for the process accordi.ncJ to the invention inasmuch as -they satisfy the above requirements concerniny the content of carboxyl or carboxylate groups and the avera~e degree of polymerization. Examples are polyarylic acids, polymethacrylic acids, polymaleic acids, polyitaconic acids, polycitraconic acid~, polyglutaconic acids, polymesaconic acids, poly-~-hydroxy acrylic acids, copolymers of 50 to 99 primary mole percent of maleic acid units and 50 to 1 primary mole percent of styrene, alkylene (for example, ethylene or propylene), vinyl alkyl ether (alkyl = CH3 to C4Hg), vinyl acetate or vinyl alcohol unlts. Further suitable copolymers are those of 50 to 99 mole percent of maleic acid and 50 to 1 mole percent of carbon monoxide, acrylic acid or metha-crylic acid.
However, the poly(aldehydo carboxylates) and/or poly (hydroxy aldehydro carboxylates) and/or poly(hydroxy carboxylates) described in our German specifications DT-OS 1 904 940, published August 6, 1970, DT-OS 1 904 941, published August 6, 1970 and DT-OS 1 942 556 published August 11, 1971 are preferably used and particularly those having an average degree of polymerization -(average viscosity) between 3 and 600, preferably between 3 and 300 and a minimum carboxyl content of 60 primary mole percent.-.
The preferred carboxylates are polymers which contain ~ ; pr1marlly C-C bonds in the principal chain and are built exclusive-:~ ly~of Y + W/2 primary mole percent of units having the general formula R

- CH - C
COOA

~ 5 ~ :

~ , , ,: .

lQ37~5 U - W primary mole percent of units ha~in~ the ~eneral formula 2 Cl (II) C~IO

.~:

,"~ '', ' ' ' " ' '-.

' ,' ' ": .

: 30 '... . ....

. ~ . ; '.
. : '. -. ~':

37~
z primary mole percent of units having the general forrr~la ~R3 IR5 f f (III~
COOA COOA

W/2 primary mole percent of units having the general formula C~12 - f (IV) CH2OH ;

V primary mole percent of units having the general formula - o - CH -(V) CH = CH2 wherein U is equal to 12 to 47, V is equll to 0 to 25, W is equal to Q to U, Y is equal to 100 - (U + V + Z) and Z is!equal to O to 20, A represents an alkali metal ion~ hydrogen ion or ammonium ion, Rl represents hydrogen, methyl, hydroxy methyl, ethyl, chlorine or brcmine, R2 and R4 are identical or dif-ferent and represent hydrogen or hydroxy-methyl, R3 and R5 are identical or different and represent hydrogen, methyl or ethyl and the boundary condi- -tion~that for W greater then 0.3 U the quotient of primary mole percent of ~car~xyl or carboxylate groups and primary mole per oe nt of hydroxyl groups is betw~en 1 and 10 must be satisfied. -The average degree of polymerization of the polymers is between 3 and 600, preferably between 3 and 300, particularly between 5 and 100. m e data on the average degree of polymerization must be so understood that their 30~ v ~ s of 3,~ 5, 100, 300 and 600 correspond to values of the re3uoed viscosity measured on 1~ solutions of free poly(aldehyde carboxylic acids) or for the poly(hydroxy cer}oxylates) and poly(h~dr3ry aldehydo carboxylates) measured on their inteYn~Y3iate products, i.e., the poly(aldehydo carboxylic acids) ~370~5 of 0.023, 0.033, 0.095, 0.200 and 0.350 decilitres per yram. For the production of the 1% poly(aldehydo carboxylic acid) solutions whichare required for the measurement the free poly(aldehydo carboxylic acids) are first covered with corresponding amounts of 5% aqueous SO2 solutions and upon completed dissolving, the same volume of 10% aqueous NaCl solutions is used for filliny up, The viscosimetric measurement is carried out at 20C.
The proportions of the units having the general for-mula (I) and (V) in the polymers to be used in the process according to the invention are given in primary mole percent ' according to E. Trommstorff, i.e., as the average number of the formula units concerned per 100 formula units (I) to (V) in the polymer molecules.
For the parameters (U, V, W, Y and Z) by which the proportions of the units having the general formulae (I) to (V) in the polymers to be used are limited, it holds true that U -is equal to 12 to 47, preferably 20 to 47, particularly 22 to 47, V is equal to 0 to 25, preferably 1 to 20, particularly 5 to -15, W is equal to 0 to U, preferably 0.3 U to U, particularly 0.5 U to U, Y is equal to 100 - (U-~V+Z) and Z is equal to 0 to 20, preferably 0 to 10, particularly 0.
For polymers in which W is greater than 0.3 U, i.e., -which contain an appreciable number of units having the general formuLa (IV) the boundary condition that the quotient of primary mole percent of carboxyl or carboxylate groups and primary mole : . .
percent of hydroxyl groups is between 2 and lO, preferably between 3 and 9, particularly between 5 and ~ must be satisfied.
Among the polymers to be used the poly(hydroxy car-boxylates), i.e., polymers for which W is practically equal to U, which thus have no or at best only a very small proportion ~
of units having the general formula (II), are particularly ~ ~-'- .

-: , pre~erred- lO 3~0 1 ~
The polymers used;~ he process according to the :invention are conventionally produced. Thus, the poly(aldehydo carboxylates) can be produced in a particularly favourahle manner by oxidative polymerization of acrolein or by~oxidativ~
co-polymerization of acrolein, i~ required, in the presence of mercaptans, particularly n-dodecyl mercaptans and/or thioethylene glycol in order to control the molecular weiyht distribution, with acrylic acid, methacrylic acid, ethacrylic acid, a-chloro acrylic acid or ~ bromo acrylic acid or by oxidative ter-polymerization with said ~, ~-unsaturated monocarboxylic acids and with an ~, ~-unsaturated dicarboxylic acid, which, if re-quired, is substituted by methyl groups or ethyl groups. The polymerization conditions must however be so chosen that the proportions of units having the general formulae (I), (II), (III) and (V) in the polymers are within the ranges mentioned herein-before and that the required degree of polymerization is main-tained. For this purpose peroxides or per acids are preferably ~;
used as oxidizing agents and simultaneously as polymerization initiators. H2O2 is pre~erably used. In the oxidative poly-merization the COOH and CO content of the polymers can be ad-justed by means of the amount of e.g. acrolein, acrylic acid and oxidizing agent used. Since the peroxidic compound acts simultaneously as a regulator, the degree of polymerization can also be influenced by its concentration and its proportion relative to the monomer. Apart from hydroxyl groups carboxyl, carbonyl, CH2OH and hemiacetal groups of the type o~ (VI a) 2 C ~ O_ as well as vinyl groups or even hydrogen atoms, for example, in ", ' ''.'' ~ID370~5 in the form of groups of the type CH3 - flI CH3 - CH
CHO (VI b) or COOH (VI c) as well as radicals of the catalyst usecl can also occur as ter-minal groups. The homo- or co-polymerization of the acrolein can be carried out as a function of the desired content o~ carboxyl groups in the polymer and also as a solution or precipitation polymerization, preferably in an aqueous medium. When using per-oxidic compounds as oxidizing agents it is advisable to apply them and, if required, the co-monomer or a portion thereof in an aqueous solution or suspension and to add the acrolein, if re-quired in mixture with the residual co-monomer, at elevated :
temperatures ranging, for example, from 50 to 100C. In case of a solution polymerization the polymers can be used directly for further reactions, if required upon concentrating the solu-tion. It is often favourable to destroy amounts of oxidizing ~ ;
.
agent still present in the solution, for example, by adding small amounts of Mn02 or active carbon. However, it is also possible to precipitate these solution polymers from the reaction mixture with the aid of a dilute acid, for example, hydrochloric acid.
Residual monomers can be recovered directly fro~ the reaction ~ ~ `
,: . ,: ., mixture, for example, by distillation. In this case the residue , -~from distillation is a highly concentrated aqueous solution of the ;; ~ polymer which , if required, can be used for further reactions.
, However, the distillation can be carried on to dryness and the pure~polymer :lS then obtained in a solid form. When carrying out a precipitation polymerization the polymers can be easily separated by filtration. The residual monomers are then contained n~the filtrate and can be further used in this form. The : ' ' ~ 9 ~
: ~ . :
' ~037~5 precipitation polymers can be further puriEied with water and, if required, while passing air therethrough.
In the poly(aldehydo carboxylates) the units of the type (II) can also be present in a completely or partially hy-drated form or, as the result of reactions with neighboring groups, in the form of cyclic structures so that cyclic, acetal and even acylal structuxes are formed:

12 (II a) ~ CH2 ¦ (II b) - CH2 - C - - CH - C C ~

\ OH HO / \ O / \ O~~' - CH2 _ f C 2- C - (II c) ~ ;

HO~ \ O ~ ~ O

5ince these structures are related to the single open ;
carbonyl structures (II3 by way easily reversible equilibria, 20 they are not particularly important.
By neutralizing the poly(aldehydo carboxylic acids) obtained by the above process, with an alkali metal hydroxide or with ammonia the corresponding poly(aldehydro carboxylates), wherein A can have the meanings mentioned hereinbefore with the exception of H, are obtained. ~

The production of the poly(hydroxy aldehydo carboxy- - -lates) and poly(hydroxy carboxylates) is also conventionally carried out. However, polymers which are produced by oxidative polymerization of acrolein or by oxidative co-polymerization of -~
acrolein to the poly(aldehydo carboxylates) and subsequent treat-ment of the polymer with a strong base, according to Cannizzaro, particularly an alkali metal hydroxide, are particularly preferred.

- :
'~ -- 1 0 -- ~ " :, : :., ~q~3~ 5 The treatment with a strony base can also be carried out simul-taneously with a condensation with formaldehyde. The polymers thus obtained contain additionally units having a yeneral formulae.

~ OEl2 - f - and 2 These units correspond to the general formulae (I) and (IV) if Rl and R4 represent hydroxymethyl. If the treatment of the poly (aldehydo carboxylates) with the strong base accordiny to Canniz-zaro is continued to the complete reaction of all the units having the general formula (II), i.e., the units originally present, then poly(hydroxy carboxylates) are formed. However, if the treatment ;
is continued only as far as a partial reaction, then poly (hydroxy aldehydo carboxylates) are formed. The poly(aldehydo carboxylic acids) obtained can be reacted in aqueous solution or suspension with the strong base, if required in the presence of formaldehyde.
The procedure is such that the formaldehyde is added in amounts -which are approximately stoichiometric with respect to the alde-hydic groups contained in the polymer. This is followed by stir-ring for a lengthy time at room temperature or at elevated temp-eratures of up to approximately 100C, preferably at 20 to 60C
while gradually adding alkali. After two hours the reaction rate can be, for example, 60 to 70~ of the theoretically complete re- -action and within 4 to 24 hours it can increase to 90 to lOOgo of ~ -the theoretically complete reaction. If the reaction is carried out in solution, then solutions containing an excess of liquor in addition to the salts of the poly~hydroxy aldehydo carboxylic acids) or poly(hydroxy carboxylic acids) are obtained. Upon neutralization they can be evaporated to dryness. By precipita-ting from the reaction mixture, for example, with methanol, the ,- ' .. - 11 -~'' .

~037~
salts are obtained in a particularly pure form. However, prior to the evaporation, it is also possible to neutralize the solution with a dilute acid, for example, hydrochloric acid or preferably formic acid, sulphuric acid, or phosphoric acid or to precipitate the free acids.
The excess liyuor should suitably be neutralized only with acids the salts of T~hich do not adversely affect the later use of the polymers. For example, carbon dioxide, hydrochloric acid, sulphuric acid, phosphoric acid, formic acid, acetic acid, fatty acids or aliphatic or aromatic sulphonic acids are suitable for this purpose. However, it is favourable to use the poly (hydroxy aldehydo carboxylic acids) or poly(hydroxy carboxylic acids) themselves in a pure solid form or in solution or, according to a particularly preferred modification, to use the poly(aldehydo carboxylic acids) obtained as an intermediate pro-duct in the production reaction mentioned hereinbefore, and there-of the readily water-soluble types, in aqueous solution or in the solid form or citric acid or fatty acids or aliphatic or aromatic sulphonic acids. In this manner neutral solutions of the salts of the poly(hydroxy aldehydo carboxylic acids) or poly(hydroxy carboxylic acids) are obtained. These solutions can be used directly. They have primarily C-C bonds in the principal chain and can be linear as well as slightly cross-linked. The poly-mers are built of at least two of the units (I) to (V) mentioned hereinbefore. These units are formed, to some extent~ in the treatment of the poly(aldehydro carboxylic acids) according to the Cannizzaro reaction. However, in this treatment inter- -molecular aldol condensations can also occur between the active CH groups, which are in the ~ position with respect to the alde-hydic groups in the poly(aldehydo carboxylic acid), and carbonyl groups of one or several neighboring chains. Cross-l ~ ~s results ~ ~

~, ' 12 - ~
. ~ .

~37al~5 When concomitantly using further co-monomers in addition to acrolein and e g. acrylic acid, as for example, ma-leic acid, the polymer also contains units (III) in the princi-pal chain in minor numbers. Their amount can be up to 20 pri-mary mole percent. The water-solubility and/or the acidity and thus the general applicability of the polymers can be controlled by them.
If the reaction of the poly(aldehydo carboxylates) is carried out with strong bases according to Cannizzaro in the pre-sence of formaldehyde, then units having the general Pormulae(I) and (IV), wherein Rl and R4 represent hydroxy-methyl groups, are formed. The degree of cross-linking can be controlled by the amount o~ aldehyde applied.
Although the oxidative polymerization or co-polymeri-zation of acrolein is a radical polymerization, the principal chains of the poly (aldehydo carboxylates) and also of the poly -(hydroxy aldehydo carboxylates) or poly(hydroxy carboxylates) -produced therefrom by Cannizzaro reaction can still contain units -having the general formula (V) in minor amounts of up to 25 pri-mary mole percent. They are formed by polymerization while opening the carbonyl double bond of the acrolein. However, they are unimportant with respect to the use according to the invention.
The terminal groups in the polymers are formed as a function o~ the reaction conditions and the reaction medium also are practically without importance. If acrolein and H2O2 are the starting material, then practically at least one of the two ter-minal groups of the poly(hydroxy carboxylates) or of the poly (hydroxy aldehydo carboxylates) always is a hydroxyl group. In all the other cases said terminal groups can be COH, CH2OH, COOH
3~ or CH2 = CH groups or hydrogen atoms as well as radicals of the catalysts used.

;~ ' , ' ~ 13 -7~5 The corresponding partial salts of the poly(aldehydo carboxylic acid), poly(hydroxy aldehydo carbo~ylic acids) or poly(hydroxy carboxylic acids), i.e., compounds constitutiny the so-called "hydrogen salts" can be used in the process ac-cording to the invention.
The zeolites rendered hydrophilic by the treatment according to the process of the invention can be processed along with the excess polyelectrolyte solution unless the presence of the zeolite is detrimental. Since, on account oE their capability of bon~ing Ca2+ and Mg2+ ions (i.e., the typical hard water salts) as complexes, the zeolites are suitable as water softeners or as builders for washing and cleaning agents, they can be mixed, for example, directly along with the excess polyelectrolyte solution, with components of conventional washing and cleaning agents. The slurry thus obtained is subsequently converted into a dry product by means oX known processes.
However, the hydrophilic zeolites can also be separated from the excess polyelectrolyte solution in a known manner, for example, by decanting, filtering or centrifuging. Depending on -the requirements to be satisfied they can then be further used eihter in the moist state or upon drying by means of known pro-cesses and devices.
Surprisingly, the wettability of the zeolites by water is very substantially improved by the treatment according to the process of the invention. Therefore, only this hydrophilic treatment enables zeolites to be used as an addition for washing and cleaning agents in relatively large proportions of the total mixture without interfering with the washing procedure.
This applies particularly to their use as builders. Thus, the condensed phosphates usually serving as builders can be entirely or partially replaced by substances which are more beneficial to ;~
' - ' - 14 ~

- . ~ .. ~ . ,.. ; ~. ;, , ., . . , . , .. ,,, ., , ., . . .. .. ,, , : , .

s the environment.
In the examples and comparison tests hereafter the improvement of the wettability of zeolites hy water ~Ihich results from the treatment according to the process o~ the invention is made clear.
Production of the Zeolites Used in the Exam~les Zeolite A - No. 1 _ _ , . . .
500 g of a solution containing 0.325 mole o~ ~la2O and 0.24 mole of Al~O3 were put into a l~litre round-bottomed flas~
having a mechanical blade agitator. While stirring vigorously, the sodium-aluminium silicate was precipitated from this receiver in an exothermic reaction by adding 270 g of a solution co~ntaining 0.34 mole ofiNa20 and 1.7 moles SiO2. After the precipitation the product was subjected to crystallization for 6 hours at 80C.
A partially crystalline zeolite A was obtained. It had the fol-lowing specification:
Na20:SiO2 = 0.2 A102 SiO2 = 1:2.5 Zeolite A - No. 2 .
620 g of a solution containing 0.67 mole of Na20 and ~-0.16 mole of A1203 were put into a l-litre round-bottomed flask having a mechanical blade agitator. While stirring vigorously, the sodium aluminium silicate was precipitated from this receiver in an exothermic reaction by adding 135 g of a solution containing 0.08 mole of Na20 and 0.49 mole of SiO2. After the precipitation the product was subjected to crystallization for 24 hours at 80C.
A crystalline zeolite A was obtained. It had the following ~;
specification:
Na20:SiO2 = 0.3 Al02:0iO2 = 1:1-325 Zeolite A - No. 3 650 g of a solution containing 0.33 mole of sodium aluminate (NaA102) were put into a l-litre round-bottomed flask ' -' - ~.: , 1(~3~ 5 having a mechanical blade agi-tator. ~Jhile stirring vigorously, the sodium~aluminum sllicate was precipitated from this receiver by aclding 0.36 mole of Na20 (as NaOH) followed by 65 ml of solu-tion containing 0.078 mole of Na20 and 0.28 mole of Si02. After the precipitation the product was subjected to crystallization for 66 hours at 100C (reflux condenser)`.
A crystalline zeolite A was obtained. It had the following specification:
Na20:Si02 = 2.0 A102:Si02 = 1:1 Zeolite A - No. 4 650 g of a solution containing 0.33 mole of sodium aluminate (NaA102) were put into a l-litre round-bottomed flask having a mechanical blade agitator. While stirring vigorously, the sodium-aluminium silioate was precipitated therefrom by adding a silica-gel suspension containing 0.41 mole of Si02 and by diluting with distilled water until the mixture had a pH of 13.5. The product was subjected to crystallization for 92 hours at 100C (reflux condenser). A crystalline zeolite A was obtained.
It had the following specification: ~ -Na20:Si02 = 0.50 A102:Si02 = 1:1 This zeolite corresponds to a zeolite A having an ideal composi-tion.
Zeolite A - No. 5 30 g of silica gel and 41 g of sodium aluminate ~ -(NaA102) in dilute aqueous solution (or suspension) were reacted in a round-bottomed flask having a mechanical blade agitator.
The amount of water for the dilution was so chosen that a pH '~
of the mixture of 13.5 could be measured electrometrically. The sodium-aluminium silicate precipitated during the reaction was subjected to crystallization for 92 hours at 100C. A crystalline zeolite A was obtained. It had the following specification:

, 3701~
Na20:SiO2 = 0.56 A102:SiO2 = 1:0.9 Zeolite A - No. 6 -430 g of a solution containiny 0.66 mole of sodium aluminate (NaA102) were put into a l-litre round bottomed flask having a mechanical blade agitator. While stirring vigourously, the sodium-aluminium silicate was precipitated there~rom by ad~
ding 120 g of a solution containing 0.14 mole of Na20 and 0.51 mole of SiO2. The product was subjectecl to crystallization for 62 hours at 100C. A crystalline zeolite ~ was obtained. It had the following specification:
Na20:SiO = 0.95 A12 Si2 = 1 0-84 Comparison Test 1 The "wettability of a non-hydrophilic standard zeo-lite (type A)" was determined as the average valua of the results of wettability tests on the zeolite samples zeolite A - No.l to zeolite A - No.6.
For thls purpose a method of testing the wettability was used. It can be characterized as follows: -Each of seven crystallizing dishes of glass (diameter 18.5 cm, height 8.5 cm) was filled with 500 ml of distilled water. ;~
A magnetic stirring rod of 42 mm length was then put into the dishes. The water in the dishes was then heated to a temperature ~ ;~
of 40C. Each of these dishes, which contained 500 ml of water having the temperature of 40C, was then placed on a magnetic stirring device in succession in order to measure the powder wettability. The magnetic stirring of said device was set at exactly 100 r.p.m. (with the dish placed thereon). From a rig-idly mounted aluminium vibrating chute (driven by an electric vibrator) exactly 2.5 g of powder were then sprinkled into the water recei~er, which was constantly stirred at 100 r.p.m. Tha -vibrator and the inclination of the vibrating chute were so ~
, .

1~370~5 adjusted that the powder (which had always been sprinkled at the same point from the upper end of the vibrating chute) ~as sprink-led within 15 to 17 seconds into the water receiver practically exactly at the centre of the assumed axis of rotation of the may-netic stirring rod so that a small heap of powder was formed at the point sprinkling. Said heap of powder rotated with the mo-tion of the water caused by the motion of the maynetic stirring rod and floated on the water surface and depending on its wet-tability it was formed due to the angle of contact bekween pow-der particles and water surface and more or less "depressed"the water surface and also depending on its wettability it "broke up" into individual powder particles at a more or less fast rate.
These powder particles were really suspended in the water. The time until the powder heaps "broke up" was then used as a crit-erion of the powder wettability. -In this test it is of course immaterial how long the absolute time lags between the start of the sprinkling and the break-up of the powder heaps actually are since they differ ~ -greatly, depending on the manner in which the test is carried :: : ' -out (i.e., depending on the speed of rotation of the agitator, the rate of sprinkling, etc.). It is merely important that the - `
test permits a well-defined, reproducible differentiation be- ~-~
~, tween powder having different degrees of good wettability. - ~-Therefore, the results of the measurements are shown in a re- -, lative scale in order to estimate the effect of increase in , , ,~, ,, wettability:
., relative wettability = Z Aufl = xtAufl 100 Z-tA fl ~A fl : , :,, :
wherein -ZtAufl represents the average powder-heap "break-up ~ -time" of non-hydrophilic zeolites, . ;"
: : , . ~'~, .'.:.
~, .

ptAufl represents the powder-heap "break-up time" of the pentasodium triphosphate (sodium polyphos-phate = STP) which is used as the reference substance and can be considered a classical washing-agent builder, xtAufl represent the powder-heap "break-up time" of the hydrophilic zeolite.

In the present case the following powder-heap "break--up times"
were measured with the zeolite A samples No. 1 to 6 mentioned hereinbefore.
Zeolite A ZtAufl Remarks No. 1 more than 2 min. rejected*
No. 2 ~5 seconds No. 3 45 seconds No. 4 more than 5 min. rejected*
No. 5 50 seconds No. 6 60 seconds Z~Aufl = 55 seconds * Although it seems that some zeolites are so poorly wettable -that even after a very long testing time unwetted powder parti~
cles are floating on the water surface, only the relatively favourable powder-heaps "break-up times" were used to determine Z~Aufl, particularly with a view to obtaining a precise criter- -ion for evalutating the effect of increase in wettability.
Prior to their use all the zeolite samples were dried over night in a drying cabinet at 120C. -Comparison Test 2 , ~ Pure pentasodium triphosphate was tested by means of the wettability test described in the comparison test 1. After

5 tests an average value of 29 seconds was obtained for the powder-heap "break-up time".
; Test ptAufl.
1 27 seconds 2 30 seconds 3 30 seconds 4 28 seconds 3 a 5 30 seconds ptAufl = 29 seconds Example l 1037015 In a 5% (by weight~ aqueous solution of a poly (aldehydo hydroxy carboxylate), produced by oxidative co-polymerization of 20 mole ~ of acrylic acid and 80 mole ~
of acrolein in aqueous hydrogen peroxide, followed hy a re-action with sodium hydroxide according to Cannizzaro, charac-terized by the parameters U = 17.1, V = 13, W = 15.4, Y = 69.9 and Z = O corresponding to a ratio of carboxyl or carboxylate to hydroxyl (including the terminal groups) of approximately 5.1 and a degree of neutralization ~N = COO- = 0.88, COO- + COOH
with p = 20 (average viscosity) 20 g of zeolite A were sus-pended per 100 g of solution at 23C. The suspension was thoroughly m.ixed for 30 minutes ,~ . .. . ~ . ,, . ~

',:
, ' , ' ' " ,;, "

~: : ~ "''' ' ',' ,: :
~ -: .:,,: : ' ': ~",'..i ' :;.: .

~03q~
with a blade agitator, whereupon the aqueous phase Ylas separated by filtration. The solid filtration residue was taken up in dis-tilled water, thoroughly mixed and after this washing process said residue was once more separated from the aqueous phase by filtration. Drying was carried out at 120C in a vacuum dryer (12 mm Hg). The dry zeolite was then yround .in a pinned di~c mill whereupon it was subjected to the wettability test. The loss on ignition was determined on the zeolite charged with poly(hydroxy carboxylate) and re.sulted in a polyelectrolyte con-tent of p % :
Zeolite A pRelative Wettability No. 1 5~ 96%
No. 2 3% 89%
No. 3 7~ 96~
No. 4 6% 97%
No. 5 2% 75% -:
No. 6 2% 77%
Example 2 In a 10% (by weight) aqueous solution of a poly(hy- -droxy carboxylate), produced by oxidative co-polymerization of .~
20 mole % of acrylic acid and 80 mole % of acrolein in aqueous ~ .
hydrogen peroxide, followed by a reaction with sodium hydroxide according to Cannizzaro, characterized by the parameters U =
17, V = 13, W = 17, Y = 70 and Z = 0 corresponding to a ratio of carboxyl or carboxylate to hydroxyl (including the terminal ~
groups) of approximately 4.9 and a degree of neutralization of ~ .
approximately 0.88 with p = 20 (average viscosity) 30 g of zeo-lite A were suspended per 100 g of solution at 25C. The sus-pension was thoroughly mixed for 30 minutes with a blade agi~
tator, whereupon the aqueous phase was separated by filtration, washed twice with distilled water and finally dried over night in a vacuum dryer at 120C. The loss on ignition was determined on a ground zeolite charged with poly(hydroxy carboxylate) and resulted in a polyelectrolyte content of p - . .. : . ... : . -. .. . . .

-~L~37al~5 Zeolite A p Relative Wettability No. l 15% 98%
No. 2 12% 96%
No. 3 10% 97%
No. 4 17% 95~
No. 5 9% 97%
No. 6 14% 95 Example 3 In a 40% (by weight) aqueous solution of a poly(hy-droxy carboxylate), produced by oxidative co-polymerization of 50% mole of acryic acid and 50% of acrolein in aqueous hydrogen peroxide, followed by a reaction with sodium hydroxide according to Cannizzaro, characterized by the parameters U - 16, V = 6, W = lS, Y = 78, Z = 0 corresponding to a ratio of carbo~yl or carboxylate to hydroxyl( including the terminal. groups) of 8.55 and a degree of neutralization of 0.87 with an average degree of polymerization of 60 (average viscosity) 25 g of zeolite A were suspended per 100 g of solution at 40C. The suspension was ::~
thoroughly mi~ed for 15 minutes with blade agitator and then ~;
zentrifuged off. The pasty zeolite phase was immediately dried in vacuo (15 mm Hg) at 120C. Upon grinding in a pinned disc .
mill the product was subjected to both the determination of the loss on ignition and the wettability test. The determination of ~ ..
loss on ignition resulted in a polyelectrolyte charge of the ~ .
: : -:;, :..
zeolite of p % :
Zeolite A p Relative Wettability -~

No. l 43% 77%
No. 2 40% 78%
No. 3 45% 79%
No. 4 57% 66~ :
No. 5 54% 81%
No. 6 47% 80%

Example 4 .

A 30% (by weight) poly(aldehydo carboxylic acid) solution was poured into a 30% (by weight) of zeolite suspen- .

sion (pH = 13.7) while stirring well, that is to say, - ~ -., :,,-.
22- ~
; '. ,'`. ': . ' ~103~0~
corresponding to 3.7% by weight of poly (aldehydo carboxylic acid) in the polyelectrolyte-zeolite mixture. The poly(aldehydo car-boxylic acid) had been produced by oxidative co-polymerization of 50 mole % of acrylic acid and 50 mole % of acrolein in a~ueous hydrogen peroxide and was characterized by the parameters U - 18, V = l, W = O, Y = 81, Z = O with an average degree of polymeriza-tion of 75 (average viscosity). After the a~dition o~ the poly (aldehydo carboxylic acid) the zeolite suspension (as such the mother liquor was used after the production of the zeolite) had a pH of 11.5. While stirring was continued a 40% (by weight) poly(hydroxy carboxylic acid) Na salt solution was then added at ~ : -27C, the amount being such that the total amount of polycarboxy-late in the mixture corresponded to 5% of polycarboxylate in mix- :-ture with 95% of zeolite. The poly(hydroxy carboxylate) used had been produced from the above poly(aldehydo carboxylic acid) by reaction with a solution of caustic soda in the presence of formaldehyde and thus was characterized by the parameters U = 18, B = 1, W = 15, Y = 81, Z = O corresponding to a ratio of carboxyl ;. ~: :
or carboxylate to hydroxyl (including the terminal groups) of 3.6 and a degree of neutralization of 0.95 (R4 = CH20H; in the - ..
units having the formula I whlch are present in an amount of 88.5 . -primary mole percent Rl = H for 81 primary mole percent and R
= CH20H for the remaining 7.5 primary mole percent). The zeolite .~
suspension thus obtained had a pH of 10.8~ It was immediately ~ .
subjected to spray drying and (according to the method of deter~
mining the loss on ignition) it had a polycarboxylate content of p %: `- ' ~ ,"' Zeolite A p Relative Wettability ~:~

No. 1 5.2% 98%
No. 2 7.3% 95%
No. 3 5.5% 96%
No. 4 6.1% 96% ~.
No. 5 7.2% 98% :: .
No. 6 5.8% 96% .

- 23-- ~
:' i .
", :' ' ', ' Æxample 5 ~37~
A 20% (by weight) poly(hydroxycarboxylate) solu~ion containing the same poly(hydroxy carboxylate) as in example 4 was sprayed on a zeolite powder at 25C. Said zeolite powder had been mixed in a paddle mixer. The amount sprayed on corres-ponded to a charge of 10% of polycarboxylate for the zeolite.
The sprayed zeolite was dried in front of a hot-air blower and subsequently ground in a pinned disc mill like the other products (with the exception of the spray-dried product) in order to avoid distortion of the results due to effects of the granular sizes in the wettability test. The method of determining the loss on ignition showed a polyelectrolyte content of the charged zeolite of p % :
Zeolite A p Relative Wettability No. l 11.5% 98%
No. 2 10.7% 97%
No. 3 12.2% 95%
No. 4 10.5% 97%
No. 5 10.2% 95%
No. 6 10.5% 92 Example 6 Analogously to the process in example 5 a zeolite-A
powder was produced by spraying with a 20% (by weight) aqueous ~
solution of a poly (aldehydo carboxylate), produced by oxidative ~ ~-co-polymerization of 50 mole % of acrycic acid and 50 mole % of ~
acrolein, followed by neutralization with sodium hydroxyde sol- -ution and characterized by the following parameters U = 14, V =

6, W = 2, Y -- ~0, Z = 0 with an average degree of polymerization -~
of 60 and a degree of neutralization of 0.75. The amount of -~
solution sprayed on was such that a 5% charge (5% of polyelec- -~
trolyte on 95~ of zeolite) was obtained. The determination of the loss on ignition showed p % of polyelectrolyte in mixture with the zeolite in the charged, dried and ground ~inal product:

, ~, :
,,:, - 24 - ;
' ~, ', ~03q~1S
Zeolite A p Relative Wettability No. 1 5.3% 79%
No. 2 5.8% 68 No. 3 5.9% 71~
No. 4 6.2% 74%
No. 5 4.7% 76%
No. 6 5.4% 71%.

,~
" ' ' " '. ' .
~" - -. - ~' . -.~ ,. ' , .~ ' . "

:' :
. .
-: .:
' ~',- ' : ~ '; ',': ,' ;:~''',''''"
:: . '. ~,'- .
''"' '~
: 30 -~ :
i , '',':.':

. :: . . . :
.: .
- 25~

; ;.: - .
~ : ~'.':'~,, ; .: . , ,::

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A process for improving the wettability of natural or synthetic zeolites, which comprises treating said zeolites with thorough mixing with an aqueous solution of at least one polycarboxylic compound selected from a polyelectrolyte poly-carboxylic acid and a completely or partially neutralized poly-carboxylate containing at least 40 primary mole percent of car-boxyl or carboxylate groups and having an average degree of polymerization (numerical average) between 3 and 5000 at a temperature between 0 and 100°C for at least five minutes, the aqueous solution being used in a concentration between approxi-mately 2 and approximately 800 g of polycarboxylic compound per litre and in an amount to provide approximately 0.01 to 10 parts by weight of polycarboxylic compound per part by weight of zeolite, the hydrophillic zeolite so obtained when required being either dried or separated from the aqueous phase.

2. A process according to claim 1, in which the zeolite is treated with the aqueous solution in a vessel with stirrer.

3. A process according to claim 1, in which the zeolite is treated with the aqueous solution in a spray mixer.

4. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic acid compound is present in an amount from 0.03 to 2 parts by weight per part by weight of zeolite.

5. A process as claimed in claim 1, 2 or 3, in which the polycarhoxylic acid compound is present in an amount from 0.05 to 1 part by weight per part by weight of zeolite.

6. A process as claimed in claim 1, 2 or 3, in which the zeolite is a powder having an average particle diameter of 0.1 to 100µm.

7. A process as claimed in claim 1, 2 or 3, in which the zeolite is in the form of a powder having an average particle diameter of 1 to 20µm.

8. A process as claimed in claim 1, 2 or 3, in which the zeolite is in the form of a powder having an average particle diameter of 1 to 10µm.

9. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic compound contains at least 50 primary mole percent of carboxyl or carboxylate groups.

10. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic compound contains at least 60 primary mole percent of carboxyl or carboxylate groups.

11. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic compound has an average degree of polymerization between 3 and 300.

12. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic compound has an average degree of polymerization between 3 and 100.

13. A process as claimed in claim 1, 2 or 3, in which the reaction temperature is from 15 to 95°C.

14. A process as claimed in claim 1, 2 or 3, in which the reaction temperature is from 20 to 50°C.

15. A process as claimed in claim 1, 2 or 3, in which the concentration of the aqueous solution is from about 5 to 500 g of polycarboxylic compound per litre.

16. A process as claimed in claim 1, 2 or 3, in which the concentration of the aqueous solution is from 15 to 400 g per litre.

17. A process as claimed in claim 1, 2 or 3, in which the polycarboxylic acid is selected from polyacrylic acids, polymethacrylic acids, polymaleic acids, polyitaconic acids, polycitraconic acids, polyglutaconic acids, polymesaconic acids, poly-.alpha.-hydroxy acrylic acids, copolymers of 50 to 99 prirnary mole percent of maleic acid units and 50 to 1 primary mole percent of styrene, ethylene, propylene, vinyl methyl ether, vinyl butyl ether, vinyl acetate or vinyl alcohol units where copolymers of 50 to 99 mole percent of maleic acid and 50 to 1 mole percent of carbon monoxide, acrylic acid or methacrylic acid.

18. A process as claimed in claim 1, 2 or 3, in which the carboxylate are selected from polymers which contain primarily C-C bonds in the principal chain and are built exclusively of Y + W/2 primary mole percent of units haviny the general formula (I), U - W primary mole percent of units having the general formula (II), Z primary mole percent of units having the general formula (III), W/2 primary mole percent of units having the general formula (IV), V primary mole percent of units having the general formula (V) wherein U is equal to 12 to 47, V is equal to 0 to 25, W is equal to 0 to U, Y is equal to 100 - (U+V+Z) and Z is equal to 0 to 20, A is an alkali metal ion, a hydrogen ion or an ammonium ion, R1 is hydrogen methyl, hydroxy methyl, ethyl, chlorine or bromine, R2 and R4 which may be the same or different are hydrogen or hydroxymethyl, R3 and R5 which may be the same or different are hydrogen, methyl or ethyl and the boundary condition that for W greater than 0.3 U the quotient of primary mole per-cent of carboxyl or carboxylate groups and the primary mole per-cent of hydroxyl groups is between 1 and 10 percent.