JPH01186A - UV-curable silicone release agent - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention: Industrial Field of Application The present invention is a polyorganosiloxane containing an epoxy functional component and a hydroxyl functional component in the molecule, and is a solvent-free type polyorganosiloxane that has excellent oil-based ink printing properties and release properties. UV rays of
This invention relates to a silicone release agent.

Conventional Technologies and Problems Conventionally, as a solvent-free, ultraviolet-curable silicone release agent, one in which an onium salt-based curing catalyst is blended with a polyorganosiloxane containing an epoxy group functional component in the molecule has been known. (Japanese Unexamined Patent Publications No. 56-38350 and 60-47064). Since these are solvent-free and UV-curable, they are excellent in environmental hygiene, fire safety, energy saving, and efficiency in releasability imparting treatment.

However, the above-mentioned polyorganosiloxane has poor compatibility with onium salt-based curing catalysts, tends to cause insufficient curing of the treated film, and requires a large amount of UV irradiation to cure to a practical level. Even in this case, there are problems such as the peeling properties of the resulting peel-treated film tend to vary, and the adhesive surface to which it is attached becomes contaminated, resulting in a decrease in adhesive performance.

Furthermore, similar to conventional silicone release agents, the formed release treatment film repels oil-based ink, resulting in poor printing performance.

Means for Solving the Problems The present inventors have overcome the above problems, and the mixture system has excellent stability and curing properties, and the resulting releasable treated film has excellent releasability properties, and is also suitable for oil-based ink printing. As a result of intensive research to develop a solvent-free and ultraviolet-curable silicone-based release agent, a new polyorganosiloxane containing an epoxy functional component and a hydroxyl functional component in the molecule was developed. It was discovered that the object could be achieved by using the following, and the present invention was completed.

That is, the present invention provides - clothing, (wherein R is an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 2 carbon atoms, X is an epoxy group-functional organic group, and Y is a hydroxyl group) It is a functional organic group, m/ (e+m+n) is 0.05 to 90%, expressed as n/ ((+m+n> is 0.5 to 90%), and has a number average molecular weight of 500 to soo , ooo polyorganosiloxane and an onium salt curing catalyst.

Function The polyorganosiloxane represented by the above general formula exhibits UV curability due to the ring-opening reaction of the epoxy functional component contained in the molecule with an onium salt curing catalyst. The release agent has excellent compatibility with the onium salt-based curing catalyst based on the chemical components, and the resulting release agent has excellent stability and exhibits good curability. Therefore, the peelable treated film obtained has excellent peeling properties, and also has excellent non-staining properties on the adhesive surface to which it is attached, and is excellent in maintaining adhesive strength of the adhesive layer.

Moreover, since the obtained releasable treated film has a polyorganosiloxane structure having a hydroxyl group, the wettability of oil-based ink is improved and good printability is exhibited.

Examples of Constituent Elements of the Invention The polyorganosiloxane used in the present invention is represented by the general formula:

In the above formula, R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group. From the viewpoint of peeling performance, a methyl group is preferable.

X is an epoxy functional organic group. For example,
γ-glycidyloxybrobyl group: β-(4-methyl-
Examples include 3,4-epoxycyclohexH3.

Y is a hydroxyl functional organic group. This group may be a hydroxyl group-containing compound that is compatible with the onium salt curing catalyst and the oil-based ink. An example is the formula: R' -0-
Examples include those represented by (-R"O)-H. In the formula, R is a polymethylene group, and R2 is an ethylene group: [
-CH,CH2-], propylene group: (CH2Cl
(CH3) ) or butylene group: CCH2Cl(
CxH+-)).

In the present invention, it is preferable that the polymethylene group (R) is a trimethylene group (CH2GHz GHz) from the viewpoint of easy availability. Also, ether unit −+R2
The number y of 0+- bonds depends on the content of the hydroxyl-functional organic group in the polyorganosiloxane, but in general, from the viewpoint of imparting printability, 1 to 100 is appropriate, particularly 1 to 4.
0 is preferred. Other examples of the hydroxyl-functional organic group (Y) include γ-hydroxypropyl group and γ-(2-hydroxyphenyl)propyl group.

In the present invention, from the viewpoint of solvent-free coating properties, polyorganosiloxanes having a number average molecular weight of 500 to 500,000 are suitable, preferably 1.000 to 100,000. In addition, eXm and n in the above-mentioned clothing allowance mean the number of each structural unit contained, but in the present invention, m/
(e+m+n) is 0.05-90%, n/(e+m+
'n) of 0.5 to 90% is suitable. That m/
If (e+m+n) is less than 0.05%, the resulting release agent will have poor curing properties, and if it exceeds 90%, the resulting release treated film will have poor peeling performance. Also, n/
If (Q + m + n ) is less than 0.5%, the compatibility with the onium salt-based curing catalyst, the curability of the resulting release agent, and the oil-based ink printability of the resulting release treated film will be poor; If it exceeds this, the peelability of the resulting peelable treated film will be poor.

The above-mentioned polyorganosiloxane containing an epoxy group-functional organic group and a hydroxyl group-functional organic group in the molecule can be prepared, for example, by the following method. That is,
It has a predetermined number of unsubstituted hydrogens so as to have the content ratio of each structural unit described above, and the remaining hydrogens are substituted with an alkyl group, cycloalkyl group, aryl group, or aralkyl group having 1 to 20 carbon atoms. Polysiloxane (a) having a number average molecular weight and an epoxy group-containing compound (b) having an ethylenic double bond such as olefin-glycidyl ether or having a functional group capable of reacting with silicon-bonded hydrogen. The polysiloxane is prepared by reacting a fixed amount with a predetermined amount of a hydroxyl group-containing compound (c) having an ethylenic double bond such as olefin-ethylene glycol or having a functional group capable of reacting with silicon-bonded hydrogen. It can be obtained by a method of introducing the epoxy group-containing compound (b) and the hydroxyl group-containing compound (c) through the unsubstituted hydrogen in (a) by hydrosilylation or the like.

In addition, in this invention, each structural unit may be continued in a row in a block shape, and may be continued in a row in a random state.

In the present invention, known onium salt curing catalysts can be used. An example is the formula Ar Nx" Z-
, R5S Z % R21Z (However, Ar is an aryl group, R is an alkyl group or an aryl group, Z- is B
F4"-, P F6-, ASF6-1S b F6
-, S b C1g -, HS 04-, C104
It is a non-basic and non-nucleophilic anion such as -.

), diazonium salts, sulfonium salts,
Examples include iodonium salts.

The onium salt curing catalyst is suitably added in an amount of 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the polyorganosiloxane. Its blending amount is 0
．． If it is less than 1 part by weight, the curability is poor, and if it exceeds 20 parts by weight, the peeling performance may be impaired.

The releasability treatment using the silicone release agent of the present invention is as follows:
This can be carried out in the same manner as in the case of conventional ultraviolet curable silicone release agents. Therefore, using an appropriate device such as a squeeze coater, the coating amount is 0.1 to 5 g/+J.
A common method is to coat the material to be treated so that the coating layer is cured by irradiating the coated surface with ultraviolet rays using an appropriate ultraviolet source such as a high-pressure mercury lamp or a metal halide lamp. The amount of ultraviolet ray irradiation is appropriately determined depending on the curing characteristics of the release agent.

There are no particular limitations on the subject to which the release agent of the present invention can be applied.

Among these, paper, plastic laminated paper, cloth, plastic laminated cloth, plastic film, metal foil, etc. are generally treated.

The release agent of the present invention is intended for solvent-free coating, but if the viscosity is high, a small amount of organic solvent may be added to lower the viscosity, and this may be dried after coating. Then, ultraviolet irradiation treatment may be performed. Therefore, it is of course possible to use it as a solution type using a solvent.

Effects of the Invention The silicone release agent of the present invention uses a special polyorganosiloxane having an epoxy functional organic group and a hydroxyl functional organic group, so the onium salt curing catalyst is difficult to separate (and the mixed system The obtained peelable treated film has excellent peeling properties and good oil-based ink printing properties.

Examples Reference Example 1 63.6 parts of allyl glycidyl ether (parts by weight, the same applies hereinafter) and 19.2 parts of ethylene glycol monoallyl ether were added to a glass three-way flask equipped with a stirring blade, a thermometer, and a dropping funnel. After stirring for 30 minutes under a stream of dry nitrogen, 0.4 part of a platinum catalyst for hydrosilylation (platinum-vinylsiloxane complex salt) was added thereto, and after further stirring for 10 minutes, the system was heated to 50°C.

(However, p:q=1:1, and are arranged randomly.) Next, 100 parts of a polydimethyl-methylhydrodiene siloxane copolymer having the above molecular structure and a number average molecular weight of 950 was added. The mixture was gradually added dropwise over about 1 hour to the stirred system heated to 50°C, and then the system was heated to 70°C and reacted for 5 hours.

The obtained reaction solution was placed in a vacuum dryer to remove unreacted substances. As a result of infrared absorption spectrum and NMR spectrum analysis, the product had the following molecular structure. Moreover, its number average molecular weight was 1.620.

Ya is -C3H60CxH40H, p:r:s=
The ratio is 4:3:1. Further, Reference Example 2 The amount of allyl glycidyl ether used was 42 parts, and the amount of ethylene glycol monoallyl ether used was 38.4 parts.
p:r:s=2:1 according to Reference Example 1 except that
:1, a polyorganosiloxane having a number average molecular weight of 1,600 was obtained.

Reference Example 3 46.0 parts of 4-vinylcyclohexene monooxide and 167.3 parts of polyethylene glycol monoallyl ether having a weight average molecular weight of 450 were mixed with 55 parts of tetrahydrofuran.
After stirring for 30 minutes under a stream of dry nitrogen, 100 parts of a platinum catalyst for hydrosilylation (platinum-vinylsiloxane complex salt) was added, and after further stirring for 10 minutes, the system was heated to 40°C. .

Next, 100 parts of the same polydimedy-methylhydrogensiloxane copolymer used in Reference Example 1 was gradually added dropwise over 1 hour to the stirred system heated to 40°C. Then, the system was heated to 45°C and reacted for 24 hours.

The obtained reaction solution was first put into a vacuum dryer to dry the tetrahydrofuran, and then the dried product was repeatedly purified in n-hebutane to remove unreacted substances, and then put into a vacuum dryer again to dry the tetrahydrofuran. - Hebutane was dried. As a result of infrared absorption spectrum and NMR spectrum analysis, the obtained product had the following molecular structure. Moreover, its number average molecular weight was 2.700.

is -C) H6-0-+Cx H40+rTH,
p:r:s=2:1:1. In addition, Reference Example 4 The amount of allyl glycidyl ether used was 85.2 parts,
According to Reference Example 1 except that ethylene glycol monoallyl ether was not used, a polyorganosiloxane having p:r:s=1:1:O and a number average molecular weight of 1.650 was obtained.

Example 1 To 100 parts of the polyorganosiloxane obtained in Reference Example 1, 4 parts of a sulfonyl cum salt curing catalyst dissolved in an organic solvent at a solid content of 50% was added and stirred to obtain a release agent of the present invention. .

Example 2 A release agent of the present invention was obtained according to Example 1 except that the polyorganosiloxane obtained in Reference Example 2 was used.

Example 3 A release agent of the present invention was obtained according to Example 1 except that the polyorganosiloxane obtained in Reference Example 3 was used.

Comparative Example A release agent was obtained according to Example 1, except that the polyorganosiloxane obtained in Reference Example 4 was used.

The release agents obtained in the evaluation test examples and comparative examples were applied using a squeeze coater.
Coat the laminated surface of polyethylene laminated kraft paper with a thickness of 120 μm so that the coating amount is 1 g/i, and then use an ultraviolet irradiation device equipped with a high-pressure mercury lamp to irradiate the release agent-coated surface and cure it. The following characteristics of the obtained release paper were investigated. Note that the amount of ultraviolet irradiation was 1 joule/cj in the case of Example 3, and 5 joules/cnf in the other cases.

[Curability 1 on release paper! The cured film was strongly rubbed with a finger, and the hardenability was evaluated based on the strength of the film.

[Printability] Letters were written on the surface of the release treated film on release paper using a commercially available oil-based marker ink, and the degree of repellency was examined.

[Peeling force 1] At 20°C and 65% R011, a commercially available adhesive tape with a width of 25III11 (manufactured by Nitto Denki Kogyo Co., Ltd., Kraft Tape l1h712) was placed on the releasable surface of the release paper by moving a rubber roller weighing 2 kg back and forth once. After crimping, a load of 50 g/cj was applied to the adhesive tape and the tape was left at 20° C. for 48 hours. After that, the load was released and the temperature was increased to 20°C.
The adhesive tape was left under 5% R, II for 2 hours, and the adhesive tape was peeled off using a shopper at a speed of 300 m/min (180°) to determine the force required for peeling.

[Residual adhesion rate] (Non-staining of the adhesive surface) After measuring the above peeling force, the adhesive tape was coated with water-resistant abrasive paper (No. 280) on a stainless steel plate (SOS27CP) at 20°C, 65% R, and II. A rubber roller weighing 2 kg was moved back and forth once to the cleaned surface to press it, and then the force required for peeling was determined in the same manner as above for the product that was left for 30 minutes. Then, the ratio of the residual adhesive force of the obtained measured value to the measured value obtained for the adhesive tape that had not been brought into contact with the releasable treated layer in the same manner as described above was calculated as the residual adhesive rate.

Show the results in a table.

Note that the results of the peeling force and residual adhesion rate are the average values of 4 samples.

As is clear from the table, the release agent of the present invention has excellent curability, and the formed release treated film has excellent non-staining properties on the adhesive surface and excellent oil-based ink printability.

Patent applicant: Nitto Electric Industry Co., Ltd.

Claims (1)

[Claims] 1. General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (However, R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group, and is a functional organic group, Y is a hydroxyl functional organic group, m/(l+m+n) is 0.05 to 90%, and n/(l+m+n) is 0.5 to 90%.) An ultraviolet curable silicone release agent comprising a polyorganosiloxane having a number average molecular weight of 500 to 500,000 and an onium salt curing catalyst. 2. The ultraviolet curable silicone release agent according to claim 1, wherein the onium salt curing catalyst is blended in an amount of 0.1 to 20 parts by weight per 100 parts by weight of polyorganosiloxane.