15  US 6,500,796 Bl  16  Other  useful  CGI  include  the  ether  hydroxypolycarboxylates, polyacrylate polymers, copoly› mers of maleic anhydride with ethylene or vinyl methyl  ether, or acrylic acid, 1,3,5-trihydroxy benzene-2,4,6- Included among the polycarboxylate CGis are a variety of  categories of useful materials. One important category of  polycarboxylate CGis encompasses the ether  polycarboxylates, including oxydisuccinate, as disclosed in  U.S. Pat. Nos. 3,128,287 and 3,635,830. See also "TMS/  TDS" CGis of U.S. Pat. No. 4,663,071. Suitable ether  polycarboxylates also include cyclic compounds, particu› larly alicyclic compounds, such as those described in U.S.  Pat. Nos. 3,923,679; 3,835,163; 4,158,635; 4,120,874 and  4,102,903.  The plot shown above is obtained by recording the  amount of base added over time to maintain the pH of the  reaction medium. T-lag for a particular crystal growth 65  inhibitor is determined graphically as described in the figure  above.  The hydroxyapatite slurry is prepared as follows:  Organic detergent CGis suitable for the purposes of the  present invention include, but are not restricted to, a wide  variety of polycarboxylate compounds.  As  used herein,  "polycarboxylate" refers to compounds having a plurality of  carboxylate groups, preferably at least 3 carboxylates. Poly- carboxylate CGI can generally be added to the composition  in acid form, but can also be added in the form of a  neutralised salt. When utilized in salt form, alkali metals,  such as sodium, potassium, and lithium, or alkanolammo› nium salts are preferred.  When utilised in salt form, alkali metals, such as sodium,  potassium and lithium, or alkanolammonium salts are pre› ferred.  Place 350 mL of distilled water ( distilled twice), 35 mL of  KCl 2.lM, 50 mL of CaC1$_{2 }$ 0.0175M and 50 mL of KH$_{2}$PO  4  0.01M in a reaction vessel. Insert a glass pH electrode and  a standard calomel reference electrode connected to an  auto-titrator. Bubble nitrogen gas and stabilize the tempera- ture of the reaction mixture to 37°  C. When temperature and  pH are stabilized, add the CGI candidate at the concentration  to be tested (e.g. 1.10- $^{6}$M). Titrate to pH 7.4 with KOH  0.05M. Then seed the reaction mixture with 5 mL of  hydroxyapatite slurry [Cas(PO$_{4}$)OH].  The following procedure can be used to build the plot  given above experimentally:  The observed t-lag value defines the efficiency of a  compound to inhibit the growth of calcium phosphate crys› tals; wherein the higher the t-lag, the better the CGI.  Typical of carboxylic compound for use herein are the  carboxylic compounds selected from glycolic acid, phytic  acid, monomeric polycarboxylic acids, homo or copoly› meric polycarboxylic acids or their salts in which the  polycarboxylic acid comprises at least two carboxylic radi› cals separated from each other by not more than two carbon  atoms.  Carboxylic Compounds  Preferably, the CGI for use in the present invention are  selected from carboxylic compounds, organic monophos› phonic acids, organic diphosphonic acids, and mixtures  thereof.  In addition, the crystal growth inhibitors, differentiate  themselves from the chelating agents by their low binding  affinity for copper defined by its Log  K,  i.e the  ML/M.L  Log  Kat 25 C., 0.1 ionic strength, of the CGI is of less than 15,  preferably less than 12.  A multicycle laundry test is performed over several (e.g.  10) cycles of repeated washing and tumble drying. The  conditions used are representative for the desired geographi› cal region (e.g. domestic washing machine used, detergent  used, rinse added product use, water hardness, clothing  articles washed etc.). At least two test legs are run in parallel,  including the composition of the invention and a separate  reference leg. After the required number of washing cycles  have been performed the test garments (articles of clothing)  are taken for comparison by expert graders under controlled  lighting conditions. The visual grading is a better/worse  comparison of the visible crystalline residue on the surface  of the test garments, comparing the test leg to the reference  leg. Dark coloured, knitted cotton articles are most suitable  for this comparison.  Still another suitable method for determining the crystal  growth inhibition property of the selected component which  is comparable to the T-lag method is by a visual grading. The  method is as follows:  The crystal growth inhibitors to be used for the purpose of  this invention have a t-lag of at least 10 minutes at a  concentration of 1.10- $^{6}$M, preferably at least 20 minutes,  most preferably at least 50 minutes.  developed by G. H. Nancollas in 1964, described in  Nancollas, G. Hand Koutsoukos, P. G. "Calcium Phosphate  Nucleation and Growth in solution."  Prag. Crystal Growth  Charact.  3, 77-102 (1980) can be used. This system consists  of measuring the growth rate of calcium phosphate crystals  seeded with hydroxyapatite ([Cas(PO$_{4}$ ) $_{3}$OH] or  HAP)  in the  presence of CaC1$_{2 }$ and NaH$_{2}$PO$_{4}$ .  Calcium phosphate  growth liberates protons that can be titrated with a strong  base. The amount of base needed to keep the pH constant  over the crystal growth enables persons skilled in the art to  measure the crystal growth rate directly as well as to  determine the effects of potential crystal growth rate inhibi› tors. A typical plot of such an experiment is given below:  Volume of  base added  (mL)  /:  t-lag  TIME  100 gr of Bio-Gelfi HTP hydroxyapatite powder is dis› persed in 1 L of distilled water. The pH of the resulting  slurry is lowered to 2.5 by dropwise addition of HCl  6N. This is then heated to boiling and refluxed while  stirring for seven days in a 2 L round-bottom flask  connected to a condenser. After cooling, to room  temperature, pH is adjusted to 12.0 by dropwise addi› tion of 50% Na OH and the slurry is refluxed for another  seven days as before. The slurry is allowed to settle for  to days and the supernatant is suctioned off. The flask  is refilled with 1.5 L of distilled water, stirred  vigorously, an allowed to settle again for two days. A  total of seven rinses as described above are performed.  The pH is adjusted to 7.0 by dropwise addition of HCl  2N while stirring vigorously. The resulting slurry is  stored at 37°  C. for eleven months. 