DE2031675C3 - Process for producing colored synthetic resin particles - Google Patents

Description

must possess (i.e. expand a cyanuric halide residue), known. The water-soluble dye is added to the monomer before the polymerization, dissolves non-toxic, water-soluble dye. io The final products are used to manufacture molded

2. The method according to claim I, characterized in formations or as color pigments for technical: -he marks, that you can use a polycondensate made of melamine twists.

and formaldehyde. British patent specification I 057 400 meets the

3. The method according to claim I, characterized by producing colorless Mclamin phenolic resins draws that one is a polycondepsate from melamine. 15 Control of the reaction pH using colorless metal urea and formaldehyde. \ bindings. These resins can, as they in contrast

4. The method according to claim!, Characterized in that the label for conventional melamine resins is not self-marked, that you have a polycondensate from urine paint, desired feet by adding and formaldehyde. Pigments in any process stage, exactly

5. The method according to claim!, Thereby marked 20 are colored.

draws that a polycondensate of phenol colored particles of thermosetting resin for

and formaldehyde. Use in coloring, thermosetting resin additives

6. The method according to claim I. Characterized compositions are in the USA patent draws that an aqueous solution from the 3 095 400 is described, but these particles are with Colored dye and a water-soluble reactive 25 water-insoluble dyes or pigments product made from melamine and formaldehyde, its

I ormaldehyde / melamine molar ratio between and 4: I and its weight ratio to

Water is between 1: 2.3 and i: 3.5, forms, and

and not suitable for use in toothpastes. The use of relatively colorless synthetic Resins as grinding, polishing and cleaning agents in. Dentifrices are also already known, e.g. B.

the resulting solution at 50 to 85 C under 30 from US patents 2 130 034 and 3 070 510,

Stir acidified with as much acid solution as just 3 251 S00 and 3 357 950.

is necessary in order to obtain a uniform mixture. The invention consists over the known

achieve and cause polycondensation. in the fact that in the manufacture of a water

7. The method according to claim 6, characterized in the impermeable thermosetting resin of the aqueous draws that instead of melamine urea in a 35 monomer solution a dye of any structure Amount used up to 80 percent by weight. or with any functional Gi lips added,

8. The method according to claim I, characterized in that only the requirement for missing toxicity (and draws that an aqueous solution of the course required for the process Urea, urea and formaldehyde forms, resistance) must meet. Surprising comes this solution with so much strong mineral acid does not turn into colourfast colored in this way acidified to catalyze the polycondensation,

the precipitated polycondensate wins and dries, and the dried polycondensate on a

Grinds particle size below about 500 microns.

bleeding particles, although according to Swiss patent specification 402 416 only reactive dyes seemed to come into question, which, however, do not respond to the requirement of a lack of toxicity.
45 The colored resinous material obtained according to the invention

Particles can be used to make toothpastes

to give an attractive and eye-catching appearance and in some cases the cleaning and polishing

The invention relates to a method of producing the effect of toothpastes to increase. It has long been recognized from colored synthetic resin particles using 50 that color plays an important role in that of non-toxic, water-soluble dyes. When assessing a product by the consumer, this process should consist of permanently colored, essentially In many cases, the task of color is to distinguish certain borrowed water-impermeable, cross-linked, high-polymer products from others and to give certain synthetic resin particles through polycondensation in water-specific properties These products point out, riger solution with dyes are obtained for 55 Colored products are usually obtained, the use in food, pharmaceuticals by releasing the desired dye to the other ingredients and cosmetics or as harmless parts, before the whole thing is mixed up the use in products apply that will be dated. Because the human bodies currently used in toothpastes can be absorbed. Dyes are all water-soluble and in which the inventive method is characterized marked ^6o toothpastes alternating large amounts entteiehnet of water, that are borne in perfect polycondensation spread the color and colors the fn the aqueous solution of a non-toxic, water entire product evenly . Another possible soluble dye dissolves. ness for uniform dyeing was a toothpaste be-From Swiss patent 402 416 is the fact Lichem in the pasta very small particles from unlösein method for producing colored aldehyde ^6. 5 colored material, /. B. the particles obtained according to the invention of the condensation products of nitrogen-containing compounds, which act as pigments, are the same as water-soluble dyes which distribute the C inip- moderately. Although such a material under pierung _c l _cm Vergröl.V-rungsg.as than from discrete, colored

Particles can be recognized, the pasta has a uniformly colored appearance to the naked eye. The prerequisite is, of course, that the particles that serve as pigments are colored with a dye are used for products for human consumption is harmless.

/ war the complete coloration of a product can be very attractive to the consumer, however Far greater effects are achieved with speckled products in which a lower mence is applied Particles has been incorporated. who are so big that they are in a composition of a different color with the naked eye! can be recognized. if If relatively large colored particles are evenly distributed, a product is obtained which is numerous Contains discrete, well-defined centers of contrasting color randomly but evenly distributed and has a striking and highly distinguishable appearance.

Granular detergent compositions. that are mottled by colored particles have been around for a long time Known time. In such products the desired The effect is achieved simply in that a small part of the detergent granulate is colored. A Such colored granules can be used from nearby circles for coloring or sprinkling a toothpaste Not used.

So that dye particles become uniform or, through agglomeration into visible particles, speckled coloring a toothpaste are suitable, the particles must not lose color and bleed and thereby making the entire toothpaste streaky. Because all the dyes approved for dentifrice are water soluble and toothpastes generally contain significant amounts of water not possible to produce suitable color-fast particles for this purpose.

It has been found that the un'.er use of non-toxic, water-soluble dyes according to the invention produced synthetic resin / particles excellent as a toothpaste pigment or, when the particles are agglomerated, for sprinkling toothpaste are suitable.

In carrying out the process of the present invention, a water-soluble monomer or resin is used polycondensed in an aqueous solution of a water-soluble, non-toxic dye under conditions, which are substantially water impermeable, crosslinked, thermosetting, highly polymerized Lead resin of the type further described. the resin particles thus obtained for use as a toothpaste pigment or, in agglomerated form, for use in speckled Toothpastes are suitable.

An essential feature of the process is that it is a non-toxic, water-soluble dye considerable time to complete the polycondensation is dissolved in the solution.

It has surprisingly been found that the resin particles formed by polycondensation in the presence of the dye solution take on the hue of the dye and in this way form colored resin particles which are extremely colorfast. When used for uniform dyeing of a toothpaste, a sufficient amount of the pigment-like acting I ^s larzpartikeln additionally serve as a grinding and polishing media, as long as the particle size is within a corresponding range.

The starting materials used for the process according to the invention are monomers and precursors, which are soluble in water and can be polycondensed and crosslinked in aqueous solution. A three-dimensional, polymeric network is required to achieve the desired color fastness of the process products.

An "essentially water-impermeable resin" is to be understood as meaning a resin that does not absorb any significant amount of water even after prolonged contact with water. The water absorption in 24 hours at 25 "C, measured according to ASTM D-57Ü-57T., Should preferably be less than 1%. The absorption of water leads to the swelling and softening of the resin particles and to the bleeding of the dye. Pasein resins are an example of thermosetting resins plastics that are ption ^r because of their relatively high Wasserabso unsuitable. It is believed that dye molecules "are trapped within the three-dimensionally cross-linked structure of thermosetting resin", and that as a result of water impermeability of these resins largely "waterproof the trapped molecules" are and selbs remain colourfast in the presence of water.

Among the preferred types of thermosetting. Crosslinked synthetic resins which can be colored in accordance with the invention include the highly polymerized urea-formaldehyde, melamine-formaldehyde, melamine-urea-formaldehyde, and phenol-formaldehyde resins. These resins can either be prepared from these monomers by polycondensation of the corresponding monomers or water-soluble, low molecular weight resins. The low molecular weight, water-soluble resins which can be used to prepare the final insoluble resin particles are conventionally prepared by thermally accelerated polymerization in the presence or absence of a catalyst. In the practice of polycondensation, pressure is used in addition to heat in some cases, e.g. B. in molding processes. The finished resin is formed by an acid-catalyzed polycondensation in which the water-soluble monomer or the low-molecular resin is converted in an aqueous solution. The type of acid catalyst is not critical, but strong acids such as H ₂ SO _{1 are} preferred. The polymer precipitate formed is dried and ground and / or sieved to an appropriate particle size. The precipitated resin is preferably subjected to a further heat treatment in order to achieve an even higher degree of condensation and crosslinking, either before or after the comminution to an appropriate particle size. This latter heat treatment makes the resin extremely hard and brittle, and these properties make the resin suitable for use as a cleaning and polishing ingredient in dentifrices.

For various applications it is important that the polymeric material is in finely divided form. The resin can precipitate in the acid-catalyzed polymerization in finely divided form, in which Trap particles of the desired size, as mentioned, can be separated by sieving, and the remaining particles can be cut to the desired size by conventional milling methods, e.g. H. in impact, Ball or tube mills, are crushed. If that

Resin precipitates as a block, the entire mass can

milled and sieved to achieve the desired particle size. Will be a final Heat treatment applied to give the resin abrasive effect, grinding can be done to the desired Particle size can be done before or after the heat treatment, however it will preferably done before the heat treatment, because it allows for the time required for the heat treatment is shortened.

The exact composition of the shark / .it only has little effect on its effectiveness as a coloring component for toothpastes, as long as the resin is the the above conditions are met, d. Ii. as long as the monomer or the low molecular weight, polymeric precursor is water-soluble and the finished product Resin is impermeable to water, crosslinked and thermosetting.

Particles obtained according to the invention for use in dentifrices consist of particles which are in the essentially all have a diameter below 500 μ and, if the resin is used as a cleaning and polishing component should be used, preferably have a diameter below 50 μ. Effect larger particles have a grainy taste in the mouth and stick between the teeth. The middle one The diameter of the particles is 5 to 40 microns and preferably 5 to 20 microns for optimal abrasion effects. Larger particles can be used to make speckle agglomerates. The ones listed here Particle diameters are determined microscopically using a calibrated eyepiece.

Any non-toxic, water-soluble dye can be used for coloring resin particles according to the invention. Suitable dyes are about the FD&C dyes, such as B .:

FD&C Blue No. 1: Brilliant Blue; Disodium salt. des 4 - {[4- (N-ethyl-p-sulfobenzylamino) phenyl] (2-sulfonium phenyl) methylene} [1- (N-ethyl-Np-sulfobenzyl) -A ² ' ⁵ -cyclohexadienimine];

FD&C Blue # 2: indigotine; Disodium salt of 5,5'-indigotine disulfonic acid;

FD&C Green No. 1: Guinea Green B; Monosodium salt of 4- [4- (N-p-sulfobenzylamino Äihyl-) diphenylmethylene] - [l- (N-ethyl-Np-sulfoniumbcnzyl) -A ² - ⁵ -cyclohexadienimin];

FD&C Red No. 2: Amaranth, trisodium salt of 1- (4-suifo-1-naphthylazo) -2-naphthol-3,6-disulfonic acid;

FD&C Red # 3: erythrosine; Disodium salt of 9-o-carboxyphenyl-6-hydroxy-2,4,5,7-tetraiodo -3-isoxanthone);

FD&C Red # 4: Ponceau-SX; Disodium salt of 2- (5-Su! Fo-2,4-xylylazo) -1-naphthol-4-sulfonic acid;

FD&C Yellow No. 5: tartrazine; Trisodium salt of 3-carboxy-5-hydroxy-1-sulfophenyl-4-p-sulfophenylazopyrazole;

FD&C Yellow No. 6: Sunset Yellow FCF; Disodium salt the l-p-sulfophenylazo ^ -naphthol-ö-sulfonic acid;

FD&C VioleU No. 1: Acid Violet 6B; Monosodium salt of 4 - ([4- (N-ethyl-p-sulfobenzylamino) -phenyl] - [4- (N-ethyl-p-sulfoniumbenzylamino) phenyl] -methylene) - (N, N-dimcthy! -A- ^{: l} -cyclohexadienimine);

The amount of dye used in the process of the invention depends on that desired relative color effect and the color properties of the selected dye. In general, the Concentration of the dye from 0.001 "to 0.30". based on the weight of the reaction mixture. The primary color characteristics are a) hue, bj luminosity or brilliance and c) saturation. Purity 5 or depth The hue can be chosen from the at will full range of available, non-toxic, water-soluble dyes can be selected. According to the Munsell color system (Munsell Hook of Color. Munsell Color Co., Inc., Baltimore,

ίο Maryland. 1429) the finished resin preferably has a Munsell-Werl of about 4 to 7 and a Muns.cH-Farhtiefe \ on over 4.

According to another colorimetric system (J. Opt. Soc. Am. 1940) is the apparent reflectivity of the resin preferably from about 0.20 to about 0.45. and the purity of excitation, albeit of Color shade to color shade fluctuates somewhat, should be over 20 ",,. The concentration of the dye used should preferably be so high that the specified color values are achieved.

Although there are numerous processes for the manufacture of essentially colorless resins by polymerization of monomers or water-soluble resins from aqueous solution are known below several examples of the production of colored resins are described in which the new process step the dissolution of a water-soluble dye in an aqueous solution of the reaction partners before the polymerization is carried out according to the invention;

Example I.

Green urea-formaldehyde resin particles were prepared according to the present invention by the following procedure manufactured:

56,065 parts of distilled water were placed in a reaction vessel equipped with a steam-hot jacket, Stirrer and thermopile was equipped. The guide was hired and the water was heated to 69C.

13.235 parts of urea were dissolved in the water, the temperature of the solution fell to 49 ° C. The urinary portal solution was 0.025 parts powdered FD&C Blue No. 1 and 0.025 parts FD&C Yellow No. 5 was added and mixing continued until the dyes had completely dissolved. To the dyed Urea solution was 30.615 parts of a 37 ″ strength stabilized formaldehyde solution and then slowly added 0.031 part of concentrated sulfuric acid. The reaction mixture was then heated to 49''C heated, and the reaction began, like a sudden lightening of the color of the reaction mixture became recognizable. As the reaction proceeded, the temperature of the mixture rose to 66 to 71 "C during the first 10 minutes.

After the reaction temperature had reached a constant value, the mixture was ^{cooled to 49 °} C. and allowed to react at this temperature for 2 hours with constant stirring. The mixture was then placed in a filter centrifuge, the resulting cake of solids was washed with water and placed in a dryer. The solids cake was dried to a moisture content of less than 10 "', at 104 ° C. The dry resin was pulverized to break up any lumps and the

⁶ S mass was sieved through a sieve with a mesh size of 420 μ. The colored resin particles were further crushed to a chemical particle size of 10 microns by ball milling. the

resulting particles are green in color (Munsell-Wcrt 4 to 7. Munsell-color depth > 4) and have been shown to be colourfast in the presence of water.

In the process described above, the critical components are in the reaction mixture the dye, the urea, the formaldehyde and the acid. So that the reaction can take place, all reactants must be absent from the mixture. The order of addition of the reactants is therefore practically irrelevant. Preferably, however, the dye is added to the mixture added before the let / th of the reactants.

In this example the dye was in powder form / ugcsct / t. but it can also be dissolved in water before the addition / to the reaction mixture and as a concentrated one aqueous solution can be added. The total amount of water used in the reaction mixture when adding the dye in this manner should take into account the amount of water in the dye solution. The dyes used in this example can be represented by any one or more of the Above listed dyes are replaced, with colorfast resin particles are obtained with those of the above example are identical except for the color.

The 37 ", ', formaldehyde solution used in this example was stabilized with 6 to 8% methanol. Formaldehyde is commercially available in the form of methanol-stabilized, aqueous solutions (1 to 12% methanol) with concentrations of 37 to 50', ' , ',, and available in the form of a white crystalline powder (paraformaldehyde). Any of these forms can be used in the present invention. However, if paraformaldehyde is used, it must be dissolved in water with the aid of a strong base and then larger concentrations of H. ₂ SO _{4 is} required to catalyze the polymerization of urea and formaldehyde.

The catalytic effect of the acid depends on the hydrogen ion concentration in the reaction mixture, and this in turn depends on the degree of dissociation of the acid and its concentration in the reaction mixture. Thus, any other acid can be used in place of H ₂ SO in this process, but larger amounts are required if weaker acids such as acetic acid are used. The strong mineral acids are preferably used.

In the example the water was added before the urea addition heated to 69 ° C, but this is not critical. The urea addition falls without preheating the water temperature below 49 C. the preferred temperature for initiating the reaction. However, as the reaction proceeds, the temperature of the mixture rises to 66 to 7 Γ C.

The reaction time can be varied within a wide range. It should be long enough to ensure a sufficient yield, e.g. B. at least about 30 minutes, but increase reaction times of more than 3 hours, the pure yields are insignificant, and the reaction should take place within this Time to be canceled.

Colored mclamin-formaldehyde resin can be used according to the process of the invention can be prepared by that described in U.S. Patent 3,251,800 The method is modified in that a dye is dissolved in the first reaction stage. Colored resins of this type are obtained by following the procedure of the following example.

Example 2

30 (X) parts of a water-soluble Mclamin-formaldehyde llar / cs 6 parts ID and C Red Nos. 2 and 150 parts of sodium chloride are dissolved in 7000 parts of water and heated to 60 C. A solution of 240 parts of concentrated nitric acid in 6500 parts of water at 60 ° C. is quickly poured into the dye / resin solution. The resulting mixture is stirred by 2 revolutions of a spatula and the movement of the mixture is quickly stopped by lowering a jet array of baffles into the mixture. After 10 minutes, the resulting resin gel is cut into sectors and removed from the rcak-

> 5 tion vessel taken. Water is pressed out of the gel, whereupon the gel spreads out in a thin layer and is dried in an oven at 100 ° C; the dried resin is then at 16 hours 100'C hardened. The hardened resin that consists of agglomerates Consists of small, red particles, is placed in a ball mill and sized to a particle size Grind from 5 to 15 microns mean diameter. The resulting, highly cross-linked, water-impermeable, thermosetting red resin particles are color-fast and do not lose color when put in water. This resin has one Munscll value of 4 to 7 and a Munsell color depth of over 4. Similar results are obtained when the FD&C Red # 2 is replaced by an equivalent amount of any of the dyes listed above is replaced.

CJ colored melamine-formaldehyde-urea resins can also be produced according to the invention as follows:

Example 3

100 parts of a commercially available, water-soluble melamine-urea-formaldehyde resin with a Melamine to urea to formaldehyde ratio of

* ° 1: 1: 4.5. as well as 2.5 parts of FD&C Violet No. 1 dissolved in 250 parts of water at 60.degree. 20 parts of concentrated hydrochloric acid (38 ", ',) are poured in and mixed with the dye / resin solution.

The movement of the mixture is interrupted, and

⁴ S this solidifies to form a gel. After the gel has set (generally after a few minutes), it is removed from the reaction vessel and heat-set at 150 ° C. for 16 hours. The hardened resin is placed in a ball mill and ground into particles with a mean diameter of about 10 microns. The resulting water-impermeable, highly cross-linked, thermosetting resin particles have a purple color, and this color does not bleed out when the particles are placed in water. This resin: has a Munsell value of 4 to 7 and a Munsell color depth of over 4.

Similar results are obtained when the violet dye of this example is replaced by an equiva lent amount of another, non-toxic, water-soluble

borrowed dye is replaced.

Colored particles from a phenol-formaldehyde resin are produced by adding a water-soluble! Dye is dissolved in the aqueous solution of formaldehyde before the formaldehyde reacts with phenol

is set. The production of essentially coloring Loose resins by reacting formaldehyde with phenol are described in US Pat. No. 3,357,950 wrote.

509620/13:

The following example illustrates the production of colored hairs by modifying thick ones known procedure in the sense of the message

Example 4

400 parts of formaldehyde (37 "ige. Mn II", methanol steelized. Aqueous solution) are placed in a reaction vessel. 4 parts of H) & C. 'Blue No. i are dissolved in the formaldehyde solution. 200 parts of phenol and 20 parts of sodium hydroxide are added to this solution. The solution is mixed and heated to 94 to 97 C for 45 minutes.

5 parts maleic anhydride. 63 parts of citric acid and 100 parts of deionized water are slowly demineralized Reaction mixture added while maintaining the temperature is kept at about v5 C. Then heat is applied to dehydrate the mixture at 105 C 40 minutes / u. The solid residue is removed from the reaction vessel taken and placed in boiling water for 2 hours. After this boiling-point hardening, the Solid in 10000 parts of water done \ on 25 C, which 50 parts of sulfuric acid were added. The water is then removed and the solid is dried and dried Cured at 85 C in an air circulation oven for 16 hours.

The blue phenol-formaldehyde resin formed is reduced to a particle size in a ball mill Crushed 5 to 40 microns, and these particles become put in boiling water for 1 hour and then air-dried at room temperature. The end product is a color-fast, blue, highly polarized. network / tes. heat-curing, finely divided phenol-formaldehyde resin. The Munsell value of this resin is 4 to 7, and the Munsell color depth is over 4.

Toothpastes generally contain a cleansing and polishing agent, a foaming agent and a humectant. a thickening or binding agent. Flavors and sweeteners and water. In the absence of a dye or other coloring substance, these components result in a product. which is generally white in color. Most commercial toothpastes are indeed white. Other colored toothpastes are also available and manufactured. by dissolving a dye in the water component of the paste during the mixing process. If the colored articles of the above examples are used as cleaning and polishing agents! are used, the colored particles act as a pigment that the toothpaste in the; gc colors the desired shade evenly. The total amount of resin particles in toothpastes for germination and polishing purposes is 10 to ^c > () ,, and preferably 20 to W) percent by weight. The depth of color achieved depends on the color of the particles themselves and their concentration in the finished paste.

Application example

F. a toothpaste that is a representative colored Contains resin, which is used both as a pigment and as a cleaning and polishing agent, according to de prepared according to the following recipe.

Weight percent

Green urine formaldehyde resin 25.0 (Example I)

Glvcerin 30.0

H \ dro \\ ethyl cellulose 1.5

Sodium Lauryl Sulphal 1.5

Flavors 0.s>

Saccharin 0.2

TinndD fluoride 0.4

Water rest

This toothpaste is an even green color and is free of stripes of color. She is an effective one Means for cleaning teeth with a minimum of abrasion.

Will the resin used in this toothpaste replaced by the resins prepared according to Examples 2, 3 and 4, then uniformly colored Items received.

Agglomerates of the resins in this example can and these for the production of gcsprenkeacn Toothpastes are used

The information on percentages and parts relate looked at the weight, unless otherwise stated is.

Claims (1)

'' patent claims: 1. Process for the production of colored, essentially water-impermeable, crosslinked, 5 Resin particles polish up through polycondensation in aqueous solution, dad u I marked that one before completed Polycondensation in the aqueous solution a halogen