JPS61157557A - Polyorganosiloxane composition - Google Patents

Abstract

PURPOSE:To provide the titled composition changing the color according to the degree of cure to enable the judgement of the cured state with eyes, by adding an anthraquinone dye to a silicone rubber composition composed mainly of a polyorganosiloxane. CONSTITUTION:(A) 100pts.wt. of a polyorganosiloxane containing >=2 units of formula I [R<1> is alkenyl, R<2> is (substituted) univalent hydrocarbon group devoid of aliphatic unsaturated group; a is 1 or 2; or 0-2; a+b is 1-3] in a molecule is compounded with (B) a polyorganohydrogen siloxane having the unit of formula II [R<3> is (substituted) univalent hydrocarbon group; c is 0-2; d is 1 or 2; c+d is 1-3] and containing >=3 hydrogen atoms bonded to Si atom, (C) 1-100ppm of platinum (compound) in terms of Pt atom and (D) 1-2,000ppm of an anthraquinone dye. The amount of the component B is selected to give 0.5-4 hydrogen atoms bonded to Si per one ArR<1> group.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a polyorganosiloxane composition whose cured state can be immediately determined by a change in color.

[Technical background of the invention and its problems] An addition reaction type liquid silicone rubber composition is an addition reaction of a polyorganosiloxane having an alkenyl group and a polyorganohydrodiene siloxane having a hydrogen atom bonded to a silicon atom with a platinum compound or the like. It is a composition that is cured using a commercially available catalyst, and is already well known (hour [43
(Refer to Publication No.-27853, etc.).

Conventionally, in order to examine the cured state of rubber obtained from these liquid silicone rubber compositions, it was necessary to actually touch the silicone rubber composition in the middle of curing and observe it with your finger, or measure the penetration and rubber hardness. I had to make a decision based on what I did.

For example, when using liquid silicone for mold making molds or liquid silicone rubber for dental impression materials, workers and dentists use silicone rubber each time they remove the silicone rubber mold from the master mold or the inside of the oral cavity. It was necessary to judge the hardening state of the rubber by touching it with one's fingers, and to continue observing it with one's fingers until it became usable. For this reason, valuable time is wasted by the workers in determining the cured state, which often interferes with the original medical treatment activities. Moreover, since it is not possible to judge when the curing is complete by touch, the mold is removed or the next work is carried out even though the rubber has not hardened sufficiently, which often leads to problems such as damage to the rubber and adhesion to the original mold. Sometimes it happened.

[Purpose of the Invention] The present invention is capable of detecting color changes without performing troublesome operations such as observing the cured state of rubber with a finger or measuring penetration and rubber hardness. The purpose of the present invention is to provide a polyorganosiloxane composition whose cured state can be easily determined.

[Structure of the Invention] As a result of intensive research aimed at improving these disadvantageous aspects, the present inventor has added a third additive to a silicone rubber composition that is cured by the reaction between a hydrosilyl group and an alkenyl group bonded to a silicon atom. It has been found that by adding an anthraquinone dye as a component, a polyorganosiloxane composition that changes color or disappears as the curing progresses and allows the cured state to be visually determined can be obtained.

That is, the polyorganosiloxane group (A) of the present invention has the following formula: %Formula% (wherein, R1 represents an alkenyl group, R2 represents a substituted or unsubstituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond,
a is an integer of 1 or 2, b is an integer of 0 to 2, and a+b is an integer of 1 to 3) Polyorganosiloxane having at least two units represented by the following in the molecule = 100 parts by weight (B) Formula: %Formula% (In the formula, R3 represents a substituted or unsubstituted monovalent hydrocarbon group, C is an integer of O to 2, d is an integer of 1 or 2, and c
+d is an integer from 1 to 3),
and a polyorganohydrodiene siloxane having at least three silicon-bonded hydrogen atoms in the molecule:
polyolylhydroxide rA) The number of hydrogen atoms bonded to a silicon atom is 0.5 to 4 per R1 of Cb.
(C) Catalyst selected from the group consisting of platinum and platinum compounds: as platinum atoms, polyorganosiloxane y (A)
and (Ω) anthraquinone dye: 1 to 2000 pp per polyorganosiloxane (A).

The present invention will be explained in more detail below.

The polyorganosiloxane (A) used in the present invention is
One molecule has at least two alkenyl groups directly bonded to a silicon atom. The polyorganosiloxane (A) may be either linear or branched, or a mixture thereof may be used.

l in the above formula (L is a vinyl group, an allyl group,
Examples include 1-butenyl group and 1-hexenyl group, but vinyl group is the most advantageous in terms of ease of synthesis. Examples include alkyl groups such as , methyl, ethyl, propyl, butyl, hexyl, and dodecyl; aryl groups such as phenyl; and aralkyl groups such as β-phenylethyl and β-phenylpropyl. In addition, examples include substituted hydrocarbon groups such as chloromethyl group and 3,3,3-trifluoropropyl group. Among these, one is easy to synthesize and is necessary for maintaining good physical properties after curing. Methyl groups are most preferred because they have a high degree of polymerization and exhibit low viscosity before curing, and when the composition of the present invention is used for casting, potting, coating, impregnation, etc. Properties suitable for this, especially before curing,
The viscosity at 25°C is 50°C in order to have adequate flowability and good physical properties after curing.
~200.000cP, especially 100-100. oo
If the viscosity is less than 50 cP, sufficient elongation and elasticity will not be obtained after curing, and if the viscosity exceeds 200,000 cP, the workability in casting, potting and other operations will be poor. Deteriorate.

The polyorganohydrodiene siloxane used in the present invention as component (B) must have at least three silicon-bonded hydrogen atoms in one molecule in order to form a network through crosslinking. It is. In the above formula, R3 and other organic groups bonded to the silicon atom of the siloxy unit include R in the above-mentioned component (A).
The same polyorganohydrodiene siloxanes (B) are exemplified, but from the viewpoint of easy synthesis, a methyl group is most preferable.
Either a branched or cyclic structure may be used, or a mixture thereof may be used.

As component (B), the compounds shown in the following a to C are preferable in that they impart good physical properties to the composition itself after curing.

a, consists of (CH3)2H5iOy2 and 5i02 units, and the content of hydrogen atoms bonded to silicon atoms is in the range of 0.3 to 1.2% by weight of the molecular weight.
N I+ -) IL Zeno Ha No kl
It is expressed by the following formula: (where p is an integer of 3 to 100, and q is an integer of 0 to 100), and the content of hydrogen atoms bonded to silicon atoms is 0 of the molecular weight. Linear polyorganohydrodiene siloxane in the range of .5 to 1.8% by weight C linear formula: (wherein P is 1 to 10G, q is an integer of O to 100), and silicon atoms The amount of linear polyorganohydrodiene siloxane (B) in which the content of hydrogen atoms bonded to is in the range of 0.5 to 1.6% by weight of the molecular weight is as follows: The number of hydrogen atoms bonded to silicon atoms in component (B) is 0.5 to 4.0 per one, preferably
The amount is 1.0 to 3.0. 0 hydrogen atoms
．． If the number of hydrogen atoms is less than 5, the curing of the composition will not proceed sufficiently and the hardness of the composition after curing will decrease, resulting in 4 hydrogen atoms.
．． If the number exceeds 0, the physical properties of the cured composition will deteriorate.

The platinum-based catalyst as component (C) used in the present invention is (A
This is to promote the addition reaction between the alkenyl group of component (B) and the hydrosilyl group of component (B).

Examples include simple platinum, chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, and platinum coordination compounds.

The amount of component (C) used is in the range of 1 to 100 pp (in terms of platinum atoms) based on component (A).

If it is less than 1 pp+s, the effects of the present invention cannot be achieved, and if it exceeds 1100 pp, no improvement in curing speed can be expected.

The anthraquinone dye used in the present invention as component (B) is most preferably one that is soluble in the polyorganosiloxane as component (A) or component (B). Since the dye can be used by being dispersed and mixed in the polyorganosiloxane composition, the dye may be soluble in organic solvents.Also, even if the dye is simply mixed and dispersed in the polyorganosiloxane composition, the effect of the present invention can be obtained. is not lost, so it can be used even if it is insoluble in components (A) and (B).

Kayaset Blue 81 is an anthraquinone dye.
4 (manufactured by Nippon Kayaku ■, trade name), Oriental Oil Blue K (manufactured by Toyo Ink Manufacturing ■, trade name), Orient Oil Violet 1730 (manufactured by Orient Chemical Industry ■,
Product name), Sumiplast Blue OA (Sumitomo Chemical ■
(product name, product name), etc. The acid used for component (D) is in the range of 1 to 2000 ppm based on component (A). t
If it is less than pp■, the effect of the present invention cannot be achieved, and
If the amount is less than 1,000 ppm, it is sufficient to observe discoloration or decolorization, and if the amount is more than that, the effect of the present invention may not be achieved.

The composition of the present invention may additionally contain a filler as needed, and may also contain a solvent or other polyorganic material to the extent that the effects of the present invention are not impaired. Such additional additives that may be used in conjunction with siloxanes typically include fumed silica, precipitated silica, quartz powder,
Examples include diatomaceous earth, glass peas, toluene, hexane, polydimethylsiloxane, etc., but additives that are naturally colored and fillers with strong hiding power, such as titanium oxide and iron oxide, are used. Combinations are not suitable for this purpose.

Note that addition reaction type liquid silicone rubber cures even if it is left at room temperature, but it is also possible to further accelerate curing by heating. Even in heat curing, the rubber changes color or disappears as it hardens, allowing the cured state to be visually clarified.

[Effects of the Invention] A rubber-like material is produced by stirring and mixing a component consisting of a polyorganosiloxane having an alkenyl group and a platinum compound and a component consisting of a polyorganohydrodiene siloxane having a hydrogen atom bonded to a silicon atom in a predetermined ratio. Although it can be made into a cured product, in the silicone rubber composition of the present invention, by coloring at least one of the polysiloxane components by adding an anthraquinone dye, it is easy to see the sufficient mixing state of the two components. The cured state can also be observed by the change in color.

[Example] The present invention will be explained below with reference to Examples. In addition, in the examples, all parts indicate parts by weight.

Example 1 100 parts of polydimethylsiloxane with a viscosity of 300 cP at 25°C and blocked with dimethylvinyl groups at both ends was mixed with an isopropyl alcohol solution of chloroplatinic acid in an amount of 20 pp as platinum.
(2) Component S-1(a) was prepared by addition and stirring.

Kayaset Blue 81 was added to 100 parts of polymethylhydrodiene siloxane consisting of (CH:q)7H3iO% and 5if2 units, containing 1.02% by weight of hydrogen atoms bonded to silicon atoms, and having a viscosity of 21 cP at 25°C.
4 (manufactured by Nippon Kayaku ■, trade name) was added at 80 ppm and stirred to prepare component S-1(b) colored blue.

Add 4 parts of S-1(b) to 100 parts of S-1(a),
When stirred, the mixture uniformly turned blue, and the adequacy of stirring could be clearly determined visually. Also, add this item to 25
When the rubber was left to cure at 80° C. and 80° C., as shown in Table 1, the blue color changed to green as the rubber hardened, and curing could be clearly determined from the color change.

Example 2 Polydimethylsiloxane base oil 10 having a viscosity of 3.000 cP at 25°C and having dimethylvinyl groups blocked at both ends.
0 parts, Crystallite VX-9S (trade name, manufactured by Ryumori Co., Ltd.) 20 parts, both ends are blocked with trimethylsilyl groups, and the hydrogen content bonded to the silicon atom is 0.8% by weight, and 2
2 parts of 20 cP linear polymethylhydrodiene siloxane at 5°C, 30 pp of isopropyl alcohol solution of chloroplatinic acid (as platinum, based on base oil)
m and Kayaset Blue 814 toluene solution (as Kayaset Blue 814 to base oil) 1
Mix 00pp■ and disperse it uniformly to make blue composition S.
-2 was prepared. When this product was left at 25° C., as shown in Table 2, the blue color disappeared (decolorized) as the rubber hardened, and curing could be clearly determined from the color change.

Example 3 100 parts of a polydimethylsiloxane base oil with a viscosity of 1 G and 000 cP at 25° C. with both ends blocked by dimethylvinylsilyl groups, 15 parts of fumed silica Aerosil 200 (manufactured by Degussa ■, trade name), (CH3) 2 US
Polymethylhydrodiene siloxane 1 consisting of iO units and 5i02 units, containing 1.02% by weight of hydrogen atoms bonded to silicon atoms, and having a viscosity of 21 cP at 25°C
．． 5 parts, chloroplatinic acid (based on base oil as platinum) 15 pp■ and a toluene solution of Oriental Oil Blue K (manufactured by Toyo Ink Mfg. ■, trade name) (Oriental Oil Blue K based on base oil) 50D
A blue composition S-3 was prepared by mixing and uniformly dispersing the p-intestines. When this product was left at room temperature, it turned green as the rubber hardened, and hardening could be determined.

Claims (4)

[Claims] (1) (A) The following formula: (R^1)_a(R^2)_bSiO_[_4_-_(
_a_+_b_)_]_/_2 (wherein, R^1 is an alkenyl group, R^2 is a substituted or unsubstituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond, and a is an integer of 1 or 2. , b is an integer of 0 to 2, and a+b is an integer of 1 to 3) Polyorganosiloxane having at least two units represented by the following in the molecule: 100 parts by weight (B) The following formula: (R^3) _cH_dSiO_[_4_-_(_c_+
_d_)_]_/_2 (wherein, R^3 represents a substituted or unsubstituted monovalent hydrocarbon group, c is an integer of 0 to 2, d is an integer of 1 or 2, and c+d is 1 to 3 polyorganohydrogensiloxane having a unit represented by (an integer of ) and having at least three silicon-bonded hydrogen atoms in the molecule; polyorganosiloxane (A)
an amount such that the number of hydrogen atoms bonded to silicon atoms is 0.5 to 4.0 per R^1 group in (C) a catalyst selected from the group consisting of platinum and platinum compounds; : A polyorganosiloxane composition characterized by comprising: platinum atoms in an amount of 1 to 100 ppm based on the polyorganosiloxane (A); and (D) anthraquinone dye: 1 to 2000 ppm based on the polyorganosiloxane (A). (2) The composition according to claim 1, wherein R^1 in (A) is a vinyl group. (3) The polyorganohydrogensiloxane of (B) has the following formula: R^4(CH_3)_2SiO-[(CH_3)HSi
O]-_p-[(CH_3)_2SiO]-_qSi(
CH_3)_2R^4 [In the formula, R^4 represents a hydrogen atom or a methyl group, and p is 1 to 100 (however, two R^
When both 4 are methyl groups, p is 3 to 100), q is 0 to
Indicates an integer of 100] The composition according to claim 1, which is a compound represented by the following. (4) The polyorganohydrogensiloxane (B) consists of (CH_3)_2HSiO1/2 units and SiO_2 units, and the content of hydrogen atoms bonded to silicon atoms is 0.3 to 1.2% by weight of the molecular weight. A composition according to claim 1.