Blocked polyisocyanate-containing curable silicone composition and textile treatment using the same

Abstract

A blocked polyisocyanate-containing curable silicone composition includes an amino group-containing organopolysiloxane, a blocked polyisocyanate and a catalyst which is an organic base compound and/or a metal compound. The composition has a high curability even under low-temperature conditions and, when used as a textile treatment, imparts textile fibers and products with good softness and water absorbency, and also has an excellent durability to washing.

Claims

1. A blocked polyisocyanate-containing curable silicone composition comprising: (A) 70 to 98 parts by weight of an organopolysiloxane having a terminal or pendant group of general formula (1) below ##STR00016## wherein R.sup.5 is a divalent hydrocarbon group of 1 to 8 carbon atoms, the letter “a” is an integer from 0 to 4, and each R.sup.6 is independently a hydrogen atom, a monovalent hydrocarbon group or acyl group of 1 to 10 carbon atoms, or a polyoxyalkylene-containing organic group of the formula
—CH.sub.2—CH(OH)CH.sub.2O—(C.sub.2H.sub.4O).sub.b—(C.sub.3H.sub.6O).sub.c—Z, wherein Z is a hydrogen atom, a substituted or unsubstituted monovalent hydrocarbon group or acyl group of 1 to 20 carbon atoms, b is an integer from 2 to 30, c is an integer from 0 to 20, and the oxyethylene units and oxypropylene units may form a block polymer or may form a random polymer; (B) 2 to 30 parts by weight of a blocked polyisocyanate which has at least two isocyanate groups per molecule, at least 50 mol % of the isocyanate groups being blocked with a thermally labile blocking agent, with the proviso that the combined amount of components (A) and (B) is 100 parts by weight; and (C) 0.01 to 10 parts by weight of a catalyst which is an organic base compound or a metal compound or both; wherein component (A) is at least one of the organopolysiloxanes of the following formulas ##STR00017## wherein n is an integer from 10 to 2,000; m is an integer from 1 to 10; and b, c and Z are as defined above.

2. The silicone composition of claim 1, wherein component (B) is a blocked polyisocyanate that includes a polyisocyanate compound consisting of aliphatic and/or alicyclic diisocyanate monomers.

3. The silicone composition of claim 2, wherein the polyisocyanate compound has an isocyanurate structure.

4. The silicone composition of claim 1, wherein the thermally labile blocking agent serving as component (B) is at least one compound selected from the group consisting of oxime compounds, pyrazole compounds and active ethylene compounds.

5. The silicone composition of claim 1, wherein the organopolysiloxane serving as component (A) includes groups selected from among hydroxyl, alkoxy, acyloxy and amino groups, at least one of the groups being in a reacted state with an isocyanate group on component (B).

6. The silicone composition of claim 1, wherein the catalyst serving as component (C) is a compound containing at least one metal selected from the group consisting of zinc, titanium, iron, tin, lead, copper, bismuth, aluminum and zirconium.

7. A silicone emulsion composition containing the silicone composition of claim 1.

8. A textile treatment containing the composition of claim 1.

Description

EXAMPLES

(1) Synthesis Examples, Working Examples of the invention and Comparative Examples are given below by way of illustration and not by way of limitation. In these Examples, all parts are indicated by weight.

(2) In the following Examples, the number-average molecular weights are polystyrene-equivalent number-average molecular weights measured by gel permeation chromatography (GPC) using the following apparatus. Instrument: HLC-802A, from Tosoh Corporation Columns: (from Tosoh Corporation) G1000HXL column (1) G2000HXL column (1) G3000HXL column (1) Carrier: Tetrahydrofuran Method of detection: Differential refractometer

(3) The viscosities were values measured at 25° C. using a Brookfield (BM-type) viscometer (from Tokyo Keiki, Inc.). .sup.1H-NMR measurements were taken in heavy chloroform using a 400 MHz FT-NMR spectrometer (JEOL Ltd.).

Synthesis Example 1

(4) A separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet was charged with 100 g of aminoalkyl group-containing organopolysiloxane of formula (A) below (molecular weight, 4,066; amine equivalent weight, 1,010 g/mol), the polyethylene glycol monobutyl monoglycidyl ether shown in formula (B) below (molecular weight, 349) in an amount of 52 g (this being the amount such that the ratio of the number of glycidyl groups on the polyethylene glycol monobutyl monoglycidyl ether to the total number of nitrogen-bonded hydrogen atoms (—NH) on the aminoalkyl group-containing organopolysiloxane becomes 1.0), and 7.4 g of isopropyl alcohol. Nitrogen gas was introduced into the system, after which the system was tightly sealed and an addition reaction was carried out for 4 hours at 80° C. Following reaction completion, removal of the low-boiling fraction was carried out for 1 hour at 80° C. and under a reduced pressure of 10 mmHg, yielding 145 g of the oily compound shown in formula (C) below. The compound had an appearance that was light-yellow and translucent, a viscosity of 490 mPa.Math.s, and an amine equivalent weight of 2,940 g/mol. Upon .sup.1H-NMR measurement of the compound, the ratio between methylene groups directly bonded to silicon atoms on the organopolysiloxane and terminal methyl groups on the butyl group of the polyethylene glycol monobutyl monoglycidyl ether that reacted with nitrogen atoms on the aminoalkyl group-containing organopolysiloxane was found to be 1:3.01, confirming that all the nitrogen atoms on the aminoalkyl group-containing organopolysiloxane had reacted with glycidyl groups on the polyethylene glycol monobutyl monoglycidyl ether. Unreacted glycidyl groups were not detected.

(5) ##STR00015##

Synthesis Example 2

(6) The interior of a separable flask fitted with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube and a dropping funnel was placed under a nitrogen atmosphere, charged with 600 parts of hexamethylene diisocyanate, and the temperature within the reactor was held at 70° C. under stirring. The isocyanurate-forming catalyst tetramethylammonium caprate was added and, when the rate of conversion reached 40%, the reaction was stepped by adding phosphoric acid. The reaction mixture was filtered, following which unreacted hexamethylene diisocyanate was removed using a thin-film evaporator. The resulting polyisocyanate had a viscosity at 25° C. of 2,500 mPa.Math.s and a number-average molecular weight of 680.

(7) The rate of conversion for isocyanurate formation was obtained by determining the surface area of the peak at the molecular weight corresponding to the isocyanurate as a proportion of the sum of the surface area of the peak at the molecular weight corresponding to the unreacted hexamethylene diisocyanate and the surface area of the peak at the molecular weight corresponding to the isocyanurate.

Synthesis Example 3

(8) A reactor like that in Synthesis Example 2 was charged with 100 parts of the isocyanurate obtained in Synthesis Example 2, 13 parts of polypropylene diol, and butyl acetate as the solvent in an amount such that the final blocked polyisocyanate ingredient concentration becomes 90 wt %, and the system was held under a nitrogen atmosphere for 3 hours at 70° C. Next, 50 parts of 3,5-dimethylpyrazole was added, and the characteristic absorption of isocyanate groups in the infrared spectrum was confirmed to have vanished. The resulting blocked polyisocyanate had an average molecular weight of 1,200.

Example 1

(9) A separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet was charged with 87.5 parts of the organopolysiloxane of formula (A) above and 12.5 parts of the blocked polyisocyanate obtained in Synthesis Example 3, the flask was flushed with nitrogen, and the flask contents were stirred for 4 hours at 120° C. Next, after cooling to room temperature, 1 part of zinc bis(2-ethylhexanoate) was added and the system was stirred for 10 minutes, giving a silicone composition.

Example 2

(10) Aside from replacing the organopolysiloxane of formula (A) with the organopolysiloxane obtained in Synthesis Example 1, a silicone composition was prepared in the same way as in Example 1.

Example 3

(11) Aside from replacing the zinc bis(2-ethylhexanoate) with iron tris(2-ethylhexanoate), a silicone composition was prepared in the same way as in Example 2.

Example 4

(12) Aside from replacing the zinc bis(2-ethylhexanoate) with dioctyltin dilaurate, a silicone composition was prepared in the same way as in Example 2.

Example 5

(13) Aside from replacing the zinc bis(2-ethylhexanoate) with dipropoxy bis(triethanolaminate)titanium, a silicone composition was prepared in the same way as in Example 2.

Example 6

(14) Aside from replacing the zinc bis(2-ethylhexanoate) with diazabicycloundecene, a silicone composition was prepared in the same way as in Example 2.

Example 7

(15) Aside from replacing the zinc bis(2-ethylhexanoate) with N-2-(aminoethyl)-3-aminopropyolmethyldimethoxysilane, a silicone composition was prepared in the same way as in Example 2.

Comparative Example 1

(16) A separable flask equipped with a thermometer, a stirrer, a reflux condenser and a nitrogen gas inlet was charged with 87.5 parts of the organopolysiloxane obtained in Synthesis Example 1 and 12.5 parts of the blocked polyisocyanate obtained in Synthesis Example 3, and the flask contents were stirred under a nitrogen atmosphere for 4 hours at 120° C., giving a silicone composition.

Comparative Example 2

(17) Aside from changing the amount of zinc bis(2-ethylhexanoate) from 1 part to 0.005 part, a silicone composition was prepared in the same way as in Example 2.

Comparative Example 3

(18) Aside from changing the amount of zinc bis(2-ethylhexanoate) from 1 part to 20 parts, a silicone composition was prepared in the same way as in Example 2.

(19) [Evaluation Tests]

(20) 1. Curability

(21) Two grams of the silicone composition obtained as described above was weighed into an aluminum laboratory dish having a 6 cm diameter and heated at 130° C. for 10 minutes. Compositions that cured completely were given a rating of “A”; compositions that only partially cured were given a rating of “B”; compositions that remained entirely uncured were given a rating of “C”. The results are shown in Table 1.

(22) 2. Storage Stability

(23) Five grams of the silicone composition was placed in a 25 mL glass bottle and left to stand for one day at 40° C., following which the appearance was examined. Compositions having a good appearance were rated as “Good”; compositions that had thickened or gelled were rated as “NG”. The results are shown in Table 1.

(24) TABLE-US-00001 TABLE 1 Curability Storage stability Example 1 A good Example 2 A good Example 3 A good Example 4 A good Example 5 A good Example 6 A good Example 7 A good Comparative Example 1 C good Comparative Example 2 B good Comparative Example 3 A NG

Example 8

(25) Using a homogenizing mixer, 60 g of the silicone composition obtained in Example 1 and 10 g of polyoxyethylene alkyl ether (Emulgen 1108, from Kao Corporation) were mixed together for 20 minutes at 2,000 rpm, and emulsified and dispersed in 20 g of water. The dispersion was then diluted with 110 g of water, giving an emulsion composition.

Example 9

(26) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Example 2, an emulsion composition was formulated and prepared in the same way as in Example 8.

Example 10

(27) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Example 3, an emulsion composition was formulated and prepared in the same way as in Example 8.

Example 11

(28) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Example 4, an emulsion composition was formulated and prepared in the same way as in Example 8.

Example 12

(29) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in

(30) Example 5, an emulsion composition was formulated and prepared in the same way as in Example 8.

Example 13

(31) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Example 6, an emulsion composition was formulated and prepared in the same way as in Example 8.

Example 14

(32) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Example 7, an emulsion composition was formulated and prepared in the same way as in Example 8.

Comparative Example 4

(33) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Comparative Example 1, an emulsion composition was formulated and prepared in the same way as in Example 8.

Comparative Example 5

(34) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Comparative Example 2, an emulsion composition was formulated and prepared in the same way as in Example 8.

Comparative Example 6

(35) Aside from replacing the silicone composition obtained in Example 1 with the silicone composition obtained in Comparative Example 3, an emulsion composition was formulated and prepared in the same way as in Example 8.

(36) [Evaluation Tests]

(37) The following evaluation tests were carried out on each of the emulsion compositions. The results are shown in Table 2.

(38) 3. Softness

(39) A test liquid was prepared by adding deionized water to the emulsion composition obtained above and diluting to a solids concentration of 0.5 wt %. A polyester/cotton broadcloth (65%/35%, from Tanigashira Shoten) was dipped for 1 minute in the test liquid, after which the cloth was squeezed using rolls at a squeezing ratio of 100%, dried for 2 minutes at 100° C., and then additionally heat treated for 2 minutes at 150° C., thereby producing a treated cloth for softness evaluation. A panel of three judges tested the treated cloth by touching it with their hands and rated the softness according to the following criteria.

(40) A: Very pleasant to the touch

(41) B: Pleasant to the touch

(42) C: Unpleasant to the touch

(43) 4. Water Absorbency

(44) A test liquid was prepared by adding deionized water to the emulsion composition obtained above and diluting to a solids concentration of 2 wt %. A polyester/cotton broadcloth (65%/35%, from Tanigashira Shoten) was dipped for 10 seconds in the test liquid, after which the cloth was squeezed using rolls at a squeezing ratio of 100% and dried for 2 minutes at 130° C. A single drop (25 μL) of tap water was deposited with a dropping pipette on the treated cloth, and the time in seconds until the drop was completely absorbed by the cloth was measured.

(45) 5. Wash Durability

(46) A test liquid was prepared by adding deionized water to the emulsion composition obtained above and diluting to a solids concentration of 2 wt %. A polyester/cotton broadcloth (65%/35%, from Tanigashira Shoten) was dipped for 10 seconds in the test liquid, after which the cloth was squeezed using rolls at a squeezing ratio of 100% and dried for 2 minutes at 130° C. The treated cloth was then washed a single time with a washing machine by a procedure in accordance with JIS L0217 103. The amount of silicone remaining on the fiber surfaces after a single wash was measured with a fluorescence x-ray spectrometer (Rigaku Corporation) and calculated as the remaining ratio (%) compared with when washing was not carried out.

(47) TABLE-US-00002 TABLE 2 Water absorbency Wash durability Softness (seconds) (%) Example 8 A 7 80 Example 9 A 6 71 Example 10 A 6 65 Example 11 A 8 76 Example 12 A 7 72 Example 13 A 5 68 Example 14 A 5 65 Comparative Example 4 A 9 5 Comparative Example 5 A 7 11 Comparative Example 6 A 11 82 Untreated cloth C 15

(48) As shown in Table 1, the silicone compositions of the invention have an excellent low-temperature curability. Also, as shown in Table 2, textile treatments using silicone compositions according to the invention are able to impart good softness and water absorbency to textiles, and also have an excellent wash durability.

(49) The silicone compositions of the invention have an excellent low-temperature curability. When used in textile treatments, they can impart textiles with good softness. In addition, they have an excellent wash durability, and can be used as high-durability binder resins.

(50) Japanese Patent Application No. 2015-100789 is incorporated herein by reference.

(51) Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims.