JPH06322272A - Ultraviolet-curing organopolysiloxane composition - Google Patents

Abstract

PURPOSE:To obtain a compsn. providing a sufficiently cured coating surface with no migration of silicone by ultraviolet irradiation by compounding specified organopolysiloxanes and other additive ingredients. CONSTITUTION:The compsn. comprises an organopolysiloxane (A) consisting of organosiloxane units of formula I [wherein R<1> is a (substd.) unsatd. org, group; R<2> a 1-30C monovalent satd. hydrocarbon group; a is 1-3; b is 0-2; and a+b=1-3] and organosiloxane units of formula II (wherein R<3> is the same as R<2>; and c is 0-3) and having at least two unsatd. groups, an organohydrogenpolysiloxane (B) wherein at least two silicon-bonded hydrogen atoms exist in the molecule and the amt. of the hydrogen groups is 100:1-1:100 (molar ratio) to the amt. of the unsatd. groups in the ingredient (A), a platinum catalyst (C), a controlling agent (D), and an organopolysiloxane compsn. (E) consisting of an organopolysiloxane and a carboxylic acid salt of a rare earth element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a UV-curable organopolysiloxane composition, and more particularly to a UV-curable organopolysiloxane composition which gives a sufficiently cured coating surface free of silicone migration by UV irradiation. .

[0002]

2. Description of the Related Art For an organopolysiloxane composition which is cured by ultraviolet irradiation, for example, an organopolysiloxane having a vinyl group bonded to a silicon atom and an organohydrogenpolysiloxane having a hydrogen group bonded to a silicon atom are photosensitized. Those that undergo an addition reaction by irradiation (see JP-A-47-32072 and JP-B-53-48198), and also an organopolysiloxane having a mercapto group bonded to a silicon atom and a vinyl group bonded to a silicon atom What is reacted with an organopolysiloxane by light irradiation in the presence of a photosensitizer (Japanese Patent Publication No. 54-6512, Japanese Patent Publication No. 57-34318, Japanese Patent Publication No. 54-48854, Japanese Patent Publication No. 54-48854) Japanese Patent No. 50067) is known.

However, in these known organopolysiloxane compositions, since the silicone migrates on the coated surface of the composition, the surface curing is liable to be insufficient, and therefore they are used for release papers, etc. Did not necessarily show satisfactory properties. That is,
When the above-mentioned known organopolysiloxane composition is used for release paper, it is applied to an object as an extremely thin coating film, but when it is cured by light irradiation, its surface curing is poor. Therefore, there are disadvantages that the peeling performance thereof changes with time, and the silicone is transferred to an adhesive in contact with the silicone.

[0004]

Therefore, for the purpose of improving the curability of the organosiloxane composition of this type to eliminate these drawbacks, the amount of functional groups in the organosiloxane is increased, and the photosensitizer is used. The method of increasing the compounding amount of the above has been proposed, but these are disadvantageous in that the peeling property is impaired or the odor is generated, which is not preferable and is not practically used. Has not reached. A method for improving the curability by using cerium oxide powder or the like is also known (see Japanese Patent Publication No. 61-53383).
Cerium oxide powder or the like has a disadvantage that its effect is insufficient because the dispersibility in organopolysiloxane is not sufficient.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an ultraviolet-curable organopolysiloxane composition which has solved the above disadvantages and drawbacks, and it relates to A) 1) the general formula R ¹
_a R ² _b SiO _{4-ab / 2} (wherein R ¹ is an unsubstituted or substituted organic group containing an unsaturated group, R ² is a monovalent saturated hydrocarbon group having 1 to 30 carbon atoms or a monovalent saturated halogenated carbon group) Hydrogen group, a is 1
3, b is 0 to 2, and an organosiloxane unit represented by a + b = 1 to 3) and 2) the general formula R ³ _c SiO _{4-c / 2} (where R is
³ is a monovalent saturated hydrocarbon group having 1 to 30 carbon atoms or a monovalent saturated halogenated hydrocarbon group, and c is an organosiloxane unit represented by 0 to 3), and at least 2 in one molecule.
Organopolysiloxanes having one unsaturated group, B) 1
Have at least two silicon-bonded hydrogen atoms in the molecule,
An organohydrogenpolysiloxane in which the amount of this silicon-bonded hydrogen group is 100: 1 to 1: 100 (molar ratio) with respect to the amount of unsaturated group in the above component A), C) a platinum catalyst, D).
A control agent, E) a) an organopolysiloxane, and b) a rare earth element-containing organopolysiloxane composition comprising a carboxylate of a rare earth element.

That is, the present inventors have conducted various investigations on an organopolysiloxane composition which is cured by ultraviolet irradiation, and as a result, A) an organopolysiloxane having at least two unsaturated groups in one molecule and B) one molecule. Addition reaction type organopolysiloxane composition comprising an organohydrogenpolysiloxane having at least two silicon-bonded hydrogen groups therein and C) a platinum-based catalyst, and a rare earth element-containing organopolysiloxane composition as component E) It was found that the composition gives a completely cured film even when irradiated with ultraviolet rays for a very short time of 0.2 seconds or less, and the cured film thus obtained is tack-free and can be used for paper and plastic. Being capable of firmly adhering to a substrate made of various metals, this composition can be solvent-free or solvent-based. , Or emulsion type, the same effect is shown. Furthermore, it was confirmed that the composition has an extended pot life, and a study on the dispersibility of this rare earth element-containing organopolysiloxane composition was conducted. Then, the present invention was completed. This will be described in more detail below.

[0007]

The organopolysiloxane as the component A) constituting the ultraviolet-curable organopolysiloxane composition of the present invention is an organopolysiloxane represented by the general formula R ¹ _a R ² _b SiO _{4 -ab / 2} (1) A random copolymer comprising a siloxane unit and an organosiloxane unit represented by the general formula R ³ _c SiO _{4 -c / 2} (2), or a block copolymer of the siloxane unit represented by 1) or 2) Although it is a polymer, it must have at least two unsaturated group-containing organic groups in its molecule.

R ¹ in the above formula is vinyl group, allyl group, alkyl vinyl ether group, acroylpropyl group, methacryloylpropyl group, cinnamoylpropyl group, γ-
Unsaturated group-containing organic groups exemplified by acrylamidopropyl groups, R ² and R ³ are monovalent saturated hydrocarbon groups having 1 to 30 carbon atoms, monovalent saturated halogenated hydrocarbon groups, methyl groups,
An alkyl group such as an ethyl group, a propyl group, a cycloalkyl group such as a cyclohexyl group, an aryl group such as a phenyl group, a tolyl group, or a chloromethyl group in which a hydrogen group bonded to these hydrocarbon groups is partially substituted with a halogen atom, Chloropropyl group, chlorophenyl group, bromopropyl group, 3.3 / 3-trifluoropropyl group, α ・ α
A group exemplified by an α-trifluorotolyl group and the like, and R ² and R ³ may be the same or different,
It is preferable that the number of carbon atoms is 19 or less.

These organosiloxanes are usually composed of a dimethylsiloxane unit, a diphenylsiloxane unit, a methylphenylsiloxane unit, a trimethylsiloxane unit, a dimethylphenylsiloxane unit, a methyldiphenylsiloxane unit, etc., and the end of the molecular chain is a triorganosilyl group. , Silanol groups, alkoxy groups,
It may be blocked with any of the hydroxyl groups, but when the composition of the present invention is used as a release agent, all groups other than the above-mentioned unsaturated groups are preferably methyl groups.

Further, the organohydrogenpolysiloxane as the component B) constituting the UV-curable organopolysiloxane composition of the present invention must have at least two ≡SiH groups in its molecule. However, this may be linear, branched, or cyclic, and may be a homopolymer or another siloxane unit, for example, a copolymer of a dimethylsiloxane unit and a methylhydrogensiloxane unit. Good. It is necessary that the ≡SiH group amount of the component B) is contained in a molar ratio of 100: 1 to 1: 100 with respect to the amount of unsaturated groups contained in the component A). Is preferably 1: 2 to 2:
A range of 1 is preferable.

Next, the platinum-based catalyst as the component C) which constitutes the ultraviolet-curable organopolysiloxane composition of the present invention is a catalyst for promoting the addition reaction between the above-mentioned components A) and B). Known catalysts may be used, and examples thereof include chloroplatinic acid, alcoholic aldehyde solutions of chloroplatinic acid, and complexes of chloroplatinic acid with various olefins and vinylsiloxanes. Although the amount of the platinum acid catalyst added is a catalytic amount, the total amount of the components A) and B) is 100 from the viewpoint of reactivity and economical efficiency.
It is desirable that the amount of platinum be within the range of 1 to 100 ppm with respect to parts.

The controlling agent as the component D) which constitutes the UV-curable organopolysiloxane composition of the present invention is a curing rate of the addition reaction type organopolysiloxane comprising the components A), B) and C) described above. It may be any known one, for example, a carbon-carbon triple bond-containing alcohol, acetone, methyl ethyl ketone, vinyl group-containing organopolysiloxane such as tetracyclo (methylvinyl) siloxane. As an example, the addition amount of this component is the total amount of A) and B) components.
The amount may be 0.01 to 5 parts by weight with respect to 100 parts by weight.

Further, the rare earth-containing organopolysiloxane composition as component E) which constitutes the ultraviolet-curable organopolysiloxane composition of the present invention is used for improving the curability of the ultraviolet-curable organopolysiloxane composition of the present invention. It is said that it is composed of a) an organopolysiloxane and b) a carboxylate of a rare earth element. The organopolysiloxane as the component (a) may be a conventionally known organopolysiloxane fluid, which is a straight-chain or branched-chain type which is substantially composed of diorganopolysiloxane units and which maintains a liquid at room temperature. It should be one.

The organic group directly connected to the silicon atom is an alkyl group such as a methyl group, an ethyl group, a propyl group, a butyl group, an alkenyl group such as a vinyl group or an allyl group, an aryl group such as a phenyl group or a tolyl group, a cyclohexyl group. Selected from a cycloalkyl group such as a group, or a chloromethyl group obtained by substituting a part or all of hydrogen atoms bonded to these carbon atoms with a halogen atom, a cyano group, a trifluoropropyl group, a cyanomethyl group, Examples of this siloxane include those whose molecular chain ends are blocked with a tolualkylsiloxy group, a hydroxyl group, a vinyl group, an alkoxy group, or the like, which may be a mixture of various organopolysiloxanes.

However, if the viscosity of the siloxane composition is too low, the amount of evaporation at high temperature will be large and the physical properties of various siloxane compositions will be impaired. If it is too high, the cerium compound, which will be described later, will be mixed smoothly. As the viscosity at 25 ° C is in the range of 10 to 10,000cs,
It is preferably in the range of 50 to 1,000 cs.

The rare earth element carboxylic acid salt of the component (b) in the rare earth element-containing organopolysiloxane composition is, for example, a carboxylic acid of cerium, which has the general formula (R ¹ COO) M ₁ . R ¹ is a monovalent hydrocarbon group described above, and M ₁ is cerium or a mixture of rare earth elements containing cerium as a main component. As the carboxylic acid, 2-ethylhexanoic acid, naphthenic acid, Examples thereof include oleic acid, lauric acid and stearic acid. Incidentally, this cerium carboxylate is preferably used as an organic solvent solution because of its ease of handling, but as the organic solvent, a solvent such as a stuttered solvent, mineral spirits, ligroin, a petroleum solvent such as petroleum ether, toluene, An aromatic solvent such as xylene is exemplified.

This rare earth element-containing organopolysiloxane composition has the above-mentioned a) organopolysiloxane, b)
It can be obtained by heat-treating a rare earth element carboxylate, but it is difficult to obtain a uniform composition at a heating temperature of 150 ° C or lower, and at 310 ° C or higher, the thermal decomposition rate of the organopolysiloxane as the component a) increases. So 15
It is preferably in the range of 0 to 310 ° C, particularly preferably in the range of 200 to 310 ° C.

Further, in the rare earth element-containing organopolysiloxane composition, since it is necessary that the rare earth element carboxylate is uniformly dispersed in the organopolysiloxane, in order to improve the uniform dispersibility. This reaction system is represented by the general formula (R ² O) M ² , wherein R ² is a monovalent hydrocarbon group, particularly an alkyl group such as isopropyl group, n-butyl group, stearyl group, octyl group, M 2 ² is titanium or zirconium, and tetraalkoxy titanium, a titanium compound exemplified by tetraalkoxy zirconium, or a zirconium compound may be added and reacted.

When the organopolysiloxane composition containing a rare earth element is prepared, the compounding ratio of a) organopolysiloxane to b) rare earth element carboxylic acid salt is as follows: a) 100 parts by weight of the component b) If it is less than 0.05 parts by weight, the effect of sufficiently improving the curability cannot be obtained, and if it is more than 5 parts by weight, the rare earth compound becomes insoluble in the organopolysiloxane and a uniform composition cannot be obtained.
It is preferable that the amount is up to 5 parts by weight.

The UV-curable organopolysiloxane composition of the present invention can be obtained by uniformly mixing predetermined amounts of the above-mentioned components A), B), C), D) and E). If necessary, a pot life extender and an antioxidant may be added to the product, and further, fillers and other additives such as ordinary diorganopolysiloxane and silica are used as long as the characteristics of the composition are not impaired. May be added.

The viscosity of this composition is not critical, and it is in the range of 50 to 1,000,000 cs when measured at 25 ° C., and when it has a high viscosity, it may be dispersed or diluted in an organic solvent before use. It is good, but when it is used without solvent, it should be in the range of 500 to 20,000 cP for ease of painting. As the solvent, any of commercially available inert solvents may be used, and aliphatic, aromatic hydrocarbons, chlorinated hydrocarbons, esters, ethers, ketones and the like are used for this.
Specifically, hexane, heptane, mineral spirits,
Toluene, xylene, trichloroethylene, tetrahydrofuran, etc. are exemplified.

The composition of the present invention is used as a varnish composition or a rubber composition depending on the type of the organopolysiloxane used as the main agent. It is used as a varnish composition or a rubber composition. When irradiated with, a completely cured film is formed in a short time such as 0.2 seconds or less.Therefore, a release agent for peeling, potting agent for telecommunications equipment, coating agent for plastics and other base materials, glass sleeve or Coating agent for optical fiber, impregnating agent for electrical insulation,
It can be widely applied as a water repellent, paint, etc. The composition of the present invention is cured by irradiation with ultraviolet rays as described above, and examples of the ultraviolet ray source include xenon lamps, low-pressure, medium-pressure, and high-pressure mercury lamps.

[0023]

EXAMPLES Synthesis examples, examples and comparative examples of the rare earth element-containing organopolysiloxane as the component E) which constitutes the UV-curable organopolysiloxane composition of the present invention will be described below. In the parts, the viscosity is the value measured at 25 ° C., and the peeling force in the examples is the following measured value. (Peeling force) After applying the adhesive (described above) to the silicone cured film on the surface of the base material, heating it at 100 ° C for 3 minutes, and then laminating the laminating paper together, leaving it at 25 ° C for 1 day, and then using the tensile tester. Is used to pull the laminated paper at an angle of 180 °, and the force (g) required for peeling the laminated paper is measured.

Synthetic Example (Synthesis of Cerium-Containing Organopolysiloxane) The molecular chain end is sealed with a trimethylsilyl group and the viscosity is 1
To 100 parts of 00cs dimethylpolysiloxane, the general formula M (OCO
C ₇ H ₁₅ ) ₃ [where M is a mixed rare earth], a terpene (C _n H _{2n + 2} ) solution of a carboxylate of a rare earth element having a rare earth content of 6.0 ± 0.1%, Octopus R [Hope Pharmaceuticals ( stock)
Product name] 10 parts and 2.1 parts of tetra-n-butyl titanate are well stirred in advance and added dropwise, and then the distillate is distilled off by heating while passing a small amount of nitrogen gas, and then at 300 ° C.
When heated for 1 hour, a uniform composition having a dark reddish brown color and almost transparent was obtained (hereinafter, abbreviated as Additive-I).

Examples 1 and 2 and Comparative Example 1 70 parts of dimethylpolysiloxane having a viscosity of 1,500 cs, both ends of which were blocked with trivinylsilyl groups, and both ends of the chain were blocked with dimethylvinylsilyl groups. , Viscosity 100
30 parts of cs dimethylpolysiloxane, both ends of the molecular chain were blocked with trimethylsilyl groups, 3 parts of 8,000 polymerization degree dimethylpolysiloxane, both ends of the molecular chains were blocked with trimethylsilyl groups, and contained 0.15 mol% of methyl vinyl unit ,
3 parts of dimethylpolysiloxane with a degree of polymerization of 8,000, both ends of the molecular chain blocked with trimethylsilyl groups, viscosity of 25cs
12 parts of methylhydrogen polysiloxane and control agent Surfynol 61 [trade name of Air Product Co.]
Two parts were mixed uniformly (hereinafter abbreviated as base A).

Separately from this, 70 parts of dimethylpolysiloxane having a viscosity of 1,500 cs, both ends of which are blocked with a trivinylsilyl group, a viscosity of which both ends are blocked with a dimethylvinylsilyl group, 30 parts of dimethylpolysiloxane of 100 cs and 150 ppm of platinum as a complex of chloroplatinic acid and vinylsiloxane were uniformly mixed (hereinafter abbreviated as base B). Then, 100 parts of the above-mentioned base A, 100 parts of this base B and 0.5 part of the additive-I obtained in the synthesis example were uniformly mixed to prepare a composition 1 (Example 1),
Composition 2 (Example 2) was prepared by adding 1.0 part of this additive-I, and composition 3 was prepared without adding this additive-I.
(Comparative Example 1) was prepared.

Next, these compositions 1 to 3 were coated on polyethylene laminated high-quality paper at 1.0 g / m ² , and 8 cm
The curability of the composition was investigated by irradiating it with a 2 kw high-pressure mercury lamp at different distances and changing the UV irradiation time, and the results shown in Table 1 were obtained. When the viscosity change with time when stored in a constant temperature layer at ℃ was measured by a rotational viscometer, the results shown in FIG. 1 were obtained.

Further, the cured film surface thus obtained was coated with an adhesive, Olivine BDS-817 [trade name of Toyo Ink Co., Ltd.], dried by heating, and then the adhesive layer was peeled off. When the peeling force of this coating film was measured, the results shown in Table 1 were obtained. The curability is shown in Table 1 as 5 for complete cure, 4 for almost complete cure, 3 for almost complete cure, 2 for partially uncured and 1 for completely uncured.

[0029]

[Table 1]

[0030]

The present invention relates to a UV-curable organopolysiloxane composition, which comprises A) an organopolysiloxane having at least two unsaturated groups in one molecule and B) an organohydrogenase as described above. It is characterized by comprising a diene polysiloxane, C) a platinum-based catalyst, D) a control agent, and E) an organopolysiloxane containing a rare earth element. It gives a fully cured coating surface, and this cured film is tack-free and firmly adheres to base materials made of paper, plastic, and various metals.
It is useful as a release agent for peeling, a coating material for various substrates, an impregnating agent for electrical insulation, a water repellent, and the like.

[Brief description of drawings]

FIG. 1 shows a correlation diagram between the elapsed time and the viscosity of the ultraviolet-curable organopolysiloxane compositions used in Examples 1 and 2 and Comparative Example 1 of the present invention.

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[Procedure amendment]

[Submission date] July 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Next, these compositions 1 to 3 were coated on a polyethylene-laminated high-quality paper at 1.0 g / m ² , and a 1 kw high-pressure mercury lamp was used to separate the ultraviolet rays at a distance of 8 cm. was examined its curability by irradiation with different irradiation time, the results of as shown in Table 1 were obtained, the rotational viscosity of the viscosity change with time when stored these compositions in a thermostat at 25 ° C. When measured with a meter, the results shown in FIG. 1 were obtained.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

Moreover, in this way the adhesive-olivine B P S-817 0 [Toyo Ink Co., Ltd. trade name was applied to the cured film surface obtained, the adhesive layer was heated and dried When the coating film was peeled off and the peeling force of this coating film was measured, the results shown in Table 1 were obtained. The curability is shown in Table 1 as 5 for complete cure, 4 for almost complete cure, 3 for almost complete cure, 2 for partially uncured and 1 for completely uncured.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

[0030]

The present invention relates to a UV-curable organopolysiloxane composition, which comprises A) an organopolysiloxane having at least two unsaturated groups in one molecule and B) an organohydrogenase as described above. It is characterized by comprising a diene polysiloxane, C) a platinum-based catalyst, D) a control agent, and E) an organopolysiloxane containing a rare earth element. It gives a fully cured coating surface, and this cured film is tack-free and firmly adheres to base materials made of paper, plastic, and various metals.
It is useful as a release agent for peeling, a coating material for various substrates, an impregnating agent for electrical insulation, a water repellent, and the like.

Claims (1)

[Claims] 1. A) 1) General formula R ¹ _a R ² _b SiO _{4 -ab / 2} (wherein R ¹ is an unsubstituted or substituted unsaturated group-containing organic group, and R ² is a group having 1 to 30 carbon atoms). Monovalent saturated hydrocarbon group or monovalent saturated halogenated hydrocarbon group, a is 1 to 3, b is 0 to 2, a + b =
And organosiloxane units represented by 1-3), 2) the general formula _{^{R 3 c SiO 4-c /}} 2 ( here R ³ is hydrocarbon monovalent saturated hydrocarbon group or a monovalent saturated halogenated C1-30 Hydrogen radical, c
Is an organosiloxane unit represented by 0 to 3) and has at least two unsaturated groups in one molecule, and B) has at least two silicon-bonded hydrogen atoms in one molecule. An organohydrogenpolysiloxane in which the amount of this silicon-bonded hydrogen group is 100: 1 to 1: 100 (molar ratio) with respect to the amount of unsaturated group in the above component A), C) a platinum-based catalyst, D) A UV curable organopolysiloxane composition comprising a control agent, E) a) an organopolysiloxane, and b) a rare earth element-containing organopolysiloxane composition comprising a carboxylate of a rare earth element.