JP2898200B2 - Electron beam curable release agent composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is useful as an electron beam-curable release agent composition, in particular, as a cured coating film exhibiting releasability, as a back surface treatment agent for adhesive tapes and a release paper coating material for adhesive labels. The present invention relates to an electron beam-curable release agent composition.

[0002]

2. Description of the Related Art Various types of electron beam-curable release agents have been proposed, but most of them have a radical-reactive functional group introduced into the siloxane main chain. It is thought that these silicone compositions react by radicals generated by electron beam irradiation, and curing proceeds, but this curing proceeds by radical reaction,
Since this curing is completed in a very short time, high productivity can be expected for this.

[0003] Therefore, this electron beam-curable release agent is used as a surface treatment agent for various substrates, and since the release agent has the property of easily releasing an adhesive substance, it is necessary to treat the back surface of an adhesive tape. It is used as an agent and a release agent for adhesive labels.

[0004]

However, when this electron beam-curable silicone is used as a release agent for release paper, the electron beam curability increases as the content of radical functional groups in the organopolysiloxane increases. Although it improves, there is a problem in that, since the radical functional group itself generally has a strong polarity, the interfacial tension and the hardness of the coating film increase with the increase in the radical functional group, and thus the peeling property to the adhesive substance is deteriorated. This also had the disadvantage that the peel force was initially small, but increased over time during lamination of the adhesive. for that reason,
With respect to this, an electron beam-curable release agent composition having a stable release force in the initial stage and having little change over time has been desired.

[0005]

SUMMARY OF THE INVENTION The present invention relates to an electron beam-curable release agent composition which solves such disadvantages and problems.

Embedded image (Where R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, R ² is a hydrogen atom or methyl group, m
Is 1 to 8, a and b are positive numbers and a + b ≦ 3), and 25 ° C.
Has a viscosity of 100 to 3,000 cp and a refractive index of 1.412 to 1.42
100 parts by weight of an organopolysiloxane which is 8, (B) Formula _{^{(2) R 3 3 SiO- [}} R 1 2 SiO] n -SiR 3 3 ········ (2) (R 1 here R ³ is the same as described above;
Divalent hydrocarbon group, hydroxyl group or alkoxy group, n is a positive number)
And 1 to 20 parts by weight of an organopolysiloxane having a viscosity at 25 ° C. of 100 to 5,000 cp and a refractive index of 1.410 or less or 1.430 or more.

That is, the present inventors have conducted various studies to develop an electron beam-curable release agent composition in which the release force is initially stable and has little change over time. When the organopolysiloxane represented by the formula (1) is used as the component (A), and the organopolysiloxane as the component (B) represented by the formula (2) is blended with the organopolysiloxane, this compound has an initial peeling force. Is stable, and when this composition is applied to a substrate and irradiated with an electron beam, it cures well. This is because the component (B) is not completely compatible with the component (A). In addition, the component (B) bleeds out in the cured film and a light peeling phenomenon occurs here. However, it has been found that the peeling force does not change even with time. Electrons with excellent physical properties required Verify that become curable release composition and completed the present invention. This is described in more detail below.

[0007]

The electron beam-curable release agent composition of the present invention comprises the component (A) comprising an organopolysiloxane having an acrylic group-containing organic group represented by the above formula (1) and the formula (2) The composition of the present invention obtained by mixing the component (A) and the component (B), which comprises the component (B) composed of an organopolysiloxane, has a stable initial peeling force, When this is applied to a substrate and irradiated with an electron beam, it cures and exhibits a light peeling property. However, since the peeling force does not change with time, this is an electron beam having excellent physical properties. It becomes a curable release agent composition.

The organopolysiloxane as the component (A) constituting the electron beam-curable release agent composition of the present invention is represented by the above formula (1)

Embedded image Wherein R ¹ is an alkyl group such as a methyl group, an ethyl group, a propyl group, or 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; The same or different unsubstituted or substituted monovalent selected from chloromethyl group, trifluoropropyl group, cyanoethyl group, etc., in which part or all of the hydrogen atoms bonded to the atoms are substituted by halogen atoms or cyano groups, etc. A hydrocarbon group, R ² is a hydrogen atom or a methyl group, m is 1 to 8, a and b are positive numbers, and a + b ≦
3.

The organopolysiloxane includes the following:

Embedded image

Embedded image Are exemplified.

It has a viscosity at 25 ° C. of 100
It should be about 3,000 cp, but its refractive index is
If it is smaller than 1.412, the curability by electron beam will be reduced.If it is larger than 1.428, the curability by electron beam will be improved, but the surface properties of the cured film will be reduced, so that it has a refractive index of 1.412 to 1.428. It may be a single siloxane or a mixture of a plurality of organosiloxanes having different degrees of polymerization and different amounts of functional groups.

The organopolysiloxane as the component (B) constituting the electron beam-curable release agent composition of the present invention is represented by the above-mentioned formula (2): R ³ ₃ SiO— [R ¹ ₂ SiO] _n —SiR ³ ₃ indicated by ········ (2), R ¹ is as defined above, monovalent hydrocarbon group R ³ is R ¹ and carbon atoms of the same type 18, a hydroxyl group or an alkoxy radical, n Is assumed to be a positive number, and the following are exemplified.

Embedded image

It has a viscosity at 25 ° C. of 100 to 5,
000 cp, which has a refractive index of 1.4
If the refractive index is 10 <(B) <1.430, the component (B) is completely compatible with the component (A), and the desired characteristics cannot be obtained. Therefore, the refractive index is 1.410 or less, or 1.430.
It is necessary to do the above.

When the mixing ratio of the component (A) and the component (B) is too large, such as (A) / (B) = 100/20, if the component (B) is too large, the curability by electron beam irradiation decreases. However, if the amount of the component (B) is too small, as in the case of (A) / (B) = 100/1 or less, the desired effect cannot be obtained because the bleed-out cannot be carried out well on the surface.
(B) = 100/1 to 100/20.
Incidentally, if necessary, the composition has an oxygen curing inhibition controlling agent such as diethylamine ethanol and piperidine,
A reaction diluent, an organic solvent, a leveling agent, a filler, an antistatic agent, an antifoaming agent, a pigment, an organopolysiloxane and the like may be added.

The electron beam curable release agent composition of the present invention is used by coating it on a substrate, such as polyester, polypropylene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, or polyimide. Paper bases such as plastic films, sheets, glassine paper, kraft paper, clay-coated paper and the like, and laminated papers such as polyethylene-laminated paper and polyethylene-laminated kraft paper are used.

The application of the composition of the present invention to these substrates may be performed by a known method such as roll coating, gravure coating, wire doctor coating, air knife coating, dipping coating and the like. If this coating amount is too small, coating unevenness occurs on the substrate and the peeling force becomes unstable, and if it is too large, the transmittance of the electron beam becomes poor and causes poor curing, This may be about 0.01 to 20.0 g / m ² .

Further, since the electron beam-curable release agent composition of the present invention is cured by electron beam irradiation, an electron beam irradiation device is required for this use. A double scan method may be used. If the acceleration voltage of the electron beam by this electron beam irradiation is less than 100 KV, the amount of transmitted energy is insufficient,
If it exceeds 00KV, it will not be economical.
If the electron beam irradiation amount is less than 0.5 Mrad, curing failure occurs, and the electron beam irradiation amount is 10 Krad.
Above, the base material deteriorates, which is not preferable, so 0.5 to 10.0
The range should be within the range of Mrad.

[0017]

EXAMPLES Examples and comparative examples of the present invention will now be described. In the examples, parts are parts by weight and viscosities are values measured at 25 ° C. Shows values measured by the following test methods. [Curability] The electron beam-curable release agent composition was applied to polyethylene laminated paper so as to be 1.0 g / m ^2, and an accelerating voltage of 165 was applied using an electron beam irradiator C-150 (trade name, manufactured by ESI).
It was shown by the amount of electron beam irradiation (Mrad) required to form a completely cured film when the film was irradiated with an electron beam at KV and cured. However, the determination of this curing was made at the time when the coated surface did not become cloudy even when rubbed with a finger.

[Releasability] The electron beam-curable release agent composition was
It is applied to polyethylene laminated paper at 1.0 g / m ² and accelerated with an electron beam irradiator C-150 (described above).
After curing by irradiating with electron beam with KV, acrylic resin solvent type adhesive, Olivain BPS-8170 is applied to the cured film surface.
[Toyo Ink Co., Ltd. product] is applied and heat-treated at 100 ° C. for 3 minutes. Then, a high-quality paper having a basis weight of 64 g / cm ² is stuck to the treated surface and aged at 25 ° C. for 20 hours. Sample was cut into 5 cm widths and 180 ° using a tensile tester.
The force (g / 5cm) required for pulling and peeling the laminated paper at a peeling speed of 300mm / min at an angle of was measured, and this value was used as the initial peeling force, and the above laminating conditions were set to 20g / cm ² at 70 ° C. Was measured after three days of pressure bonding under a load of.

[Residual Adhesion Rate] A cured film of an organopolysiloxane composition is formed on polyethylene laminated paper in the same manner as in the case of peelability, and polyester tape Lumirror 31B [a product of Nitto Denko Corporation] is formed on the surface. And a heat treatment at 70 ° C. for 20 hours with a load of 20 g / cm ² , and then the tape was peeled off and the tape was attached to a stainless steel plate. Next, the force (g / 2.5 cm 2) required for peeling off the treated tape from the stainless steel plate was measured, and the percentage of the force required for peeling off the untreated standard tape was defined as the residual adhesion ratio. .

Examples 1 to 6 and Comparative Examples 1 to 3 Formulas having a viscosity of 800 cp and a refractive index of 1.414 as the component (A)

Embedded image And the viscosity as component (B) is 100, 500, 5,000 cp.
Where the refractive index is 1.403

Embedded image Organopolysiloxane II with a viscosity of 3,000 cp
Equation with refractive index 1.404

Embedded image An organopolysiloxane III having a viscosity of 5,000
Formula with refractive index 1.381 in cp

Embedded image Organopolysiloxane IV with a viscosity of 3,000 cp
And the refractive index is 1.423

Embedded image An organopolysiloxane V represented by the following formula was produced.

Next, the organopolysiloxane I and the organopolysiloxanes II to V were blended at the blending ratios shown in Table 1 to obtain 10 types of electron beam-curable release agent compositions having the viscosity and refractive index shown in Table 1. Was prepared and applied to a polyethylene laminated paper so that the coating amount was 1.0 g / m ^2, and then this was irradiated with an electron beam from an electron beam irradiator C-150 (described above) to cure it. The curability, initial and temporal removability, and residual adhesion (residual contact) were examined, and the results shown in Table 1 were obtained.

[0022]

[Table 1]

[0023]

The present invention relates to an electron beam-curable release agent composition comprising an organopolysiloxane represented by the formula (1) as the component (A) and a compound represented by the formula (B) as the component (B). It is characterized by being composed of the organopolysiloxane shown in 2), but it is easily cured by irradiation of about 3 Mrad of electron beam, and this cured film has little migration, and peels at the initial stage. Since the force is stable and does not change even with the elapse of time, it has an advantage that a cured film having a stable peeling force with a light peeling can be obtained.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ identification code FI C08L 83:04) (58) Investigated field (Int.Cl. ⁶ , DB name) C09J 7/00-7/04 C08F 299 / 08 C08L 83/07 C09K 3/00

Claims (1)

(57) [Claims] (1) Formula (A) (Where R ¹ is the same or different unsubstituted or substituted monovalent hydrocarbon group, R ² is a hydrogen atom or a methyl group, m is 1 to 8, a and b are positive numbers, and a + b ≦ 3) , 100～3,000Cp viscosity at 25 ° C., Oruganopo polysiloxane 100 parts by weight of a refractive index of 1.412~1.428, (B) formula _{^{R 3 3 SiO- [R 1 2}} SiO] n -SiR 3 3 ( where R ¹ is the same as described above, R ³ is a monovalent hydrocarbon group having 1 to 18 carbon atoms, a hydroxyl group or an alkoxy group, n is a positive number), the viscosity at 25 ° C. is 100 to 5,000 cp, and the refractive index is 1 to 20 parts by weight of an organopolysiloxane having a molecular weight of 1.410 or less or 1.430 or more, an electron beam-curable release agent composition.