Earth alkali carbonate, surface modified by at least one polyhydrogensiloxane

Abstract

The present invention relates to an earth alkali carbonate-containing filler material having a volatile onset temperature of ≧350° C., which is at least partially surface modified by using at least one polyhydrogensiloxane for increasing the hydrophobicity and/or decreasing the moisture pick up, a process for preparing such a surface modified earth alkali carbonate-containing filler material, a fibre and/or filament and/or film and/or thread and/or breathable film comprising the surface modified earth alkali carbonate-containing filler material as well as an article comprising the surface modified earth alkali carbonate-containing filler material and/or the fibre and/or filament and/or film and/or thread and/or breathable film, preferably its use in polyester products.

Claims

1. A surface modified earth alkali carbonate-containing filler material having a volatile onset temperature of ≧350° C., the surface modified earth alkali carbonate-containing filler comprising: a) at least one earth alkali carbonate-containing filler material, and b) a treatment layer located on at least a part of the surface of the at least one earth alkali carbonate-containing filler material, wherein i) the treatment layer comprises at least one polyhydrogensiloxane and reaction products thereof, and ii) the surface modified earth alkali carbonate-containing filler material comprises the treatment layer in a total amount of from 0.7 to 6.0 mg/m.sup.2, based on the surface modified earth alkali carbonate-containing filler material, wherein the at least one polyhydrogensiloxane is at least one compound of the following Formula I: ##STR00003## wherein x>y>0, and x+y is in the range from 5 to 200; R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are independently from each other hydrogen or a saturated linear or branched alkyl group having 1 to 6 carbon atoms, and R.sup.7 is a methyl group.

2. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material is precipitated calcium carbonate (PCC) and/or natural ground calcium carbonate (NGCC).

3. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material is precipitated calcium carbonate (PCC) in one or more of aragonitic, vateritic and calcitic mineralogical crystal forms.

4. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material is natural ground calcium carbonate (NGCC) from one or more of marble, limestone, or chalk, and/or dolomite.

5. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material has a) a weight median particle size diameter d.sub.50 in the range from 0.3 μm to 10.0μm, and/or b) a specific surface area (BET) in the range from 1.0 m.sup.2/g to 10.0 m.sup.2/g, as measured by the BET nitrogen method.

6. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material has a) a weight median particle size diameter d.sub.50 in the range from 0.5μm to 5.0μm, and/or b) a specific surface area (BET) in the range from 3.0 m.sup.2/g to 8.0 m.sup.2/g, as measured by the BET nitrogen method.

7. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material has a weight median particle size diameter d.sub.50 in the range from 1.0μm to 3.0μm.

8. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the at least one earth alkali carbonate-containing filler material has a weight median particle size diameter d.sub.50 in the range from 1.5μm to 1.8μm.

9. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material features a volatile onset temperature of ≧400° C.

10. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material features a volatile onset temperature of >450 ° C.

11. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material features a volatile onset temperature of ≧500° C.

12. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material features a higher volatile onset temperature than the same filler material comprising a treatment layer consisting only of at least one saturated aliphatic linear or branched carboxylic acid and salty reaction products thereof and/or at least one mono-substituted succinic anhydride and salty reaction products thereof and/or at least one alkyl phosphoric acid ester and salty reaction products.

13. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material has a moisture pick up susceptibility of from 1.2 to 0.1 mg/g.

14. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material has a moisture pick up susceptibility of from 1.1 to 0.2 mg/g.

15. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein the surface modified earth alkali carbonate-containing filler material has a moisture pick up susceptibility of from 1.0 to 0.3 mg/g.

16. The surface modified earth alkali carbonate-containing filler material according to claim 1, wherein R.sup.1, R.sup.2, R.sup.3, R.sup.4, R.sup.5 and R.sup.6 are methyl.

Description

EXAMPLES

(1) Measurement Methods

(2) The following measurement methods are used to evaluate the parameters given in the examples and claims.

(3) Measurement of the Total Volatiles

(4) For the purpose of the present application, the “total volatiles” associated with filler materials and evolved over a temperature range of 25 to 350° C. is characterized according to % mass loss of the filler material sample over a temperature range as read on a thermogravimetric (TGA) curve.

(5) TGA analytical methods provide information regarding losses of mass and volatile onset temperatures with great accuracy, and is common knowledge; it is, for example, described in “Principles of Instrumental analysis”, fifth edition, Skoog, Holler, Nieman, 1998 (first edition 1992) in Chapter 31 pages 798 to 800, and in many other commonly known reference works. In the present invention, thermogravimetric analysis (TGA) is performed using a Mettler Toledo TGA 851 based on a sample of 500+/−50 mg and scanning temperatures from 25 to 980° C. at a rate of 20° C./minute under an air flow of 80 ml/min.

(6) The skilled man will be able to determine the “volatile onset temperature” by analysis of the TGA curve as follows: the first derivative of the TGA curve is obtained and the inflection points thereon between 150 and 600° C. are identified. Of the inflection points having a tangential slope value of greater than 45° relative to a horizontal line, the one having the lowest associated temperature above 200° C. is identified. The temperature value associated with this lowest temperature inflection point of the first derivative curve is the “volatile onset temperature”.

(7) The “total volatiles” evolved on the TGA curve is determined using Stare SW 9.01 software. Using this software, the curve is first normalised relative to the original sample weight in order to obtain mass losses in % values relative to the original sample. Thereafter, the temperature range of 25 to 350° C. is selected and the step horizontal (in German: “Stufe horizontal”) option selected in order to obtain the % mass loss over the selected temperature range.

(8) Particle Size Distribution (Mass % Particles with a Diameter<X) and Weight Median Diameter (d.sub.50) of a Particulate Material

(9) As used herein and as generally defined in the art, the “d.sub.50” value is determined based on measurements made by using a Sedigraph™ 5100 of Micromeritics Instrument Corporation (operating instrument software version 1.04) and is defined as the size at which 50% (the median point) of the particle volume or mass is accounted for by particles having a diameter equal to the specified value.

(10) The method and the instrument are known to the skilled person and are commonly used to determine the particle size distribution of fillers and pigments. The measurement is carried out in an aqueous solution of 0.1 wt.-% Na.sub.4P.sub.2O.sub.7 and 0.05 wt-% of a low molecular weight sodium polyacrylate dispersant. The samples are dispersed using a high speed stirrer and supersonics.

(11) BET Specific Surface Area of a Material

(12) Throughout the present document, the specific surface area (in m.sup.2/g) of the filler material is determined using the BET method (using nitrogen as adsorbing gas), which is well known to the skilled man (ISO 9277:1995). The total surface area (in m.sup.2) of the filler material is then obtained by multiplication of the specific surface area and the mass (in g) of the filler material prior to treatment.

(13) Moisture Pick-up

(14) The term “moisture pick-up susceptibility” in the meaning of the present invention refers to the amount of moisture absorbed on the surface of the filler material and is determined in mg moisture/g of the dry treated filler material product after exposure to an atmosphere of 10 and 85% of relative humidity, resp., for 2.5 hours at a temperature of +23° C. (±2° C.). The treated filler material product is first held at an atmosphere of 10% of relative humidity for 2.5 hours, then the atmosphere is changed to 85% of relative humidity, where the sample is held for another 2.5 hours. The weight increase between 10% and 85% relative humidity is then used to calculate the moisture pick-up in mg moisture/g of dry treated filler material product.

(15) Hydrophobicity

(16) The “hydrophobicity” of a filler material product is evaluated at +23° C. by determining the minimum water to ethanol ratio in a volume/volume based water/ethanol-mixture needed for the settling of the majority of said filler material product, where said filler material product is deposited on the surface of said water/ethanol-mixture by passage through a house hold tea sieve. The volume/volume base is related to the volumes of both separate liquids before blending them together and do not include the volume contraction of the blend. The evaluation at +23° C. refers to a temperature of +23° C.±1° C.

(17) A 8:2 volumetric ratio of a water/ethanol-mixture has typically a surface tension of 41 mN/m and a 6:4 volumetric ratio of a water/ethanol-mixture has typically a surface tension of 26 mN/m measured at +23° C. as described in the “Handbook of Chemistry and Physics”, 84th edition, David R. Lide, 2003 (first edition 1913).

(18) Residual Total Moisture Content Measurement of Calcium Carbonate-containing Filler Material

(19) The residual total moisture content of the earth alkali carbonate-containing filler material is measured according to the Karl Fischer coulometric titration method, desorbing the moisture in an oven at 220° C. and passing it continuously into the KF coulometer (Mettler Toledo coulometric KF Titrator C30, combined with Mettler oven DO 0337) using dry N.sub.2 at 100 ml/min for 10 min. A calibration curve using water has to be made and a blind of 10 min gas flow without a sample has to be taken in account.

Example 1

(20) This example relates to the preparation of a surface modified calcium carbonate-containing filler material in accordance with the process of the present invention.

(21) For the preparation of the surface modified calcium carbonate-containing filler material product, marble from Carrara, Italy was wet ground at 25 wt.-% in tap water in a horizontal ball mill (Dynomill) and spray dried. The obtained calcium carbonate-containing filler material features a d.sub.50 of approximately 1.7 microns, a top cut (d.sub.98) of 5.0 μm and a specific surface area of 4.1 m.sup.2/g and a residual moisture content of 0.06 wt.-%.

(22) The obtained spray dried calcium carbonate-containing filler material was further treated as outlined in the following tests:

(23) The aqueous emulsion of polyhydrogensiloxane as described in the examples below was prepared immediately before use. Prior addition to the carbonate the emulsion was intensively mixed by shaking.

(24) Test 1 (Prior Art; PA1)

(25) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3 000 rpm. Thereafter, a 1:1 mixture (by weight) of dry stearic acid and dry palmitic acid powder was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(26) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(27) Test 2 (Prior Art; PA2)

(28) 500 g of the spray dried calcium carbonate-containing filler material was heated overnight in an oven at 150° C. and directly added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3 000 rpm. Thereafter, a blend of alkenyl succinic anhydrides having a purity of ≧96.5% (Cas number 68784-12-3; Hydrores AS 1000 of Kemira Oyj, Finland) was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(29) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(30) Test 3 (Prior Art; PA3)

(31) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3 000 rpm. Thereafter, a mixture of 2-octyl-1-dodecan phosphoric acid mono ester and 2-octyl-1-dodecan phosphoric acid di ester (the ratio between mono-ester and di-ester is 45 mol-%:55 mol-%) was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(32) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(33) Test 4 (Prior Art; PA4)

(34) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH). Thereafter, octanoic acid (SIGMA-Aldrich order N°. O3907) was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(35) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(36) Tests 5, 6 and 10 (Invention; IE1, IE2, IE6)

(37) For each test, 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3 000 rpm. Thereafter, an aqueous emulsion of 80 wt.-% of polymethylhydrogensiloxane (CAS #63148-57-2 or 9004-73-3, available as SILRES BS-94 from Wacker Chemie AG, Germany), based on the total weight of the emulsion, was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(38) The obtained surface modified calcium carbonate-containing filler materials were stored in a closed plastic bag. For analysis purposes the samples were taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(39) Test 7 (Invention; IE3)

(40) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH). Thereafter, a 50 wt.-% aqueous emulsion of polymethylhydrogensiloxane (available as SILRES BS-94 from Wacker Chemie AG, Germany), based on the total weight of the emulsion, was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 100° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(41) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analysed immediately. The results are presented in table 2.

(42) Test 8 (Invention; IE4)

(43) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 5 minutes at 120° C. and 3 000 rpm. Thereafter, a 98 wt.-% aqueous emulsion of polymethylhydrogensiloxane (available as SILRES BS-94 from Wacker Chemie AG, Germany), based on the total weight of the emulsion, was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes. Thereafter, 500 ppm of a polydimethylsiloxane (Dow Corning 200 Fluid 1000 CS) was added and the content was further mixed for 5 minutes at 120° C. and 3 000 rpm.

(44) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analysed immediately. The results are presented in table 2.

(45) Test 9 (Invention; IE5)

(46) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3 000 rpm. Thereafter, a 80 wt.-% aqueous emulsion of polymethylhydrogensiloxane (available from Sigma Aldrich as order N° 81330; CAS N° 63148-57-2; Viscosity 15-40 mPa.Math.s at 20° C.), based on the total weight of the emulsion, was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(47) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(48) Test 11 (Invention; IE7)

(49) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH). Thereafter, a 80 wt.-% aqueous emulsion of polymethylhydrogensiloxane (available as SILRES BS-94 from Wacker Chemie AG, Germany), based on the total weight of the emulsion, was introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 150° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(50) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analysed immediately. The results are presented in table 2.

(51) Test 12 (Invention; IE8)

(52) 500 g of the spray dried calcium carbonate-containing filler material was added to an MTI Mixer (available from MTI Mischtechnik International GmbH) and the sample was activated for 10 minutes at 120° C. and 3000 rpm. Thereafter, an aqueous emulsion of 80 wt.-% of polymethylhydrogensiloxane (CAS #63148-57-2 or 9004-73-3, available as SILRES BS-94 from Wacker Chemie AG, Germany) and octanoic acid (available from SIGMA-Aldrich under order N°. O3907) were introduced to the mixer in a quantity such as indicated in Table 1. The contents of the mixer were mixed at 120° C. under a stirring speed of 3 000 rpm for a period of 10 minutes.

(53) The obtained surface modified calcium carbonate-containing filler material was stored in a closed plastic bag. For analysis purposes the sample was taken out of the closed plastic bag and analyzed immediately. The results are presented in table 2.

(54) TABLE-US-00001 TABLE 1 PA1 PA2 PA3 PA4 IE1 IE2 IE3 IE4 IE5 IE6 IE7 IE8 Test 1 2 3 4 5 6 7 8 9 10 11 12 treatment 1.0 0.5 0.8 1.0 0.5 0.6 1.5 1.2 1.1 3.0 1.2 0.5* level [wt.-%] 0.1.sup.# treatment 10/ 10/ 10/ 10/ 10/ 10/ 10/ 15/ 10/ 10/ 10/ 10/ time.sup.+/ 120 120 120 120 120 120 100 120 120 120 150 120 temperature ([min]/[° C.]) .sup.+refers to the total treatment time of the calcium carbonate-containing filler material with the polyhydrogensiloxane *refers to the amount of polyhydrogensiloxane. .sup.#refers to the amount of and octanoic acid.

(55) The results for the analysis of the surface modified calcium carbonate-containing filler material as described above are outlined in table 2.

(56) TABLE-US-00002 TABLE 2 PA1 PA2 PA3 PA4 IE1 IE2 IE3 IE4 IE5 IE6 IE7 IE8 Test 1 2 3 4 5 6 7 8 9 10 11 12 Moisture pick-up 0.4 0.4 0.6 0.3 1.0 1.0 0.8 0.6 0.9 0.8 0.9 0.9 [mg/g] Volatile onset 293 302 278 278 >500 >500 >500 >500 >500 >500 >500 >500 temperature [° C.] Hydrophobicity 50 75 65 — 75 60 70 — 55 50 50 50 [vol/vol-%]

(57) From the data given in Table 2, it can be gathered that the surface modified calcium carbonate-containing filler material of the present invention shows excellent properties. In particular, it is shown that the surface modified calcium carbonate-containing filler material of the present invention has a volatile onset temperature of ≧350° C. and a low moisture pick up susceptibility of less than 1.2 mg/g at high hydrophobicity.