JPH0136876B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has excellent printing properties, particularly with water-based inks such as fountain pens, water-based pens, and printer inks, and has ionizable properties that can provide a release layer with good release properties against adhesives. This invention relates to a radiation-curable releasable treatment agent.

Release agents are widely used as back-treatment agents for pressure-sensitive tape substrates and release agents for pressure-sensitive label separators. As release agents, polyorganosiloxanes, copolymers of acrylic esters, waxes, paraffins, etc. have been used or proposed, but the printing properties of the surface of the release layer, especially the printing properties when using water-based inks, still remain. is insufficient. Therefore, when printing on the back-treated surface of a pressure-sensitive tape or the non-adhesive surface of the release paper of a pressure-sensitive label, it is essential to treat it with a release agent that has both printability and peelability. However, there was no release agent suitable for such applications.

Furthermore, treated substrates that require such printability are required to have good writability and the feel of normal paper, so they are more likely to be treated with normal high-quality paper than processed paper such as resin-coated paper or film laminated paper. It is preferable to use paper without a seal, such as paper. However, with such unfilled paper, the release agent has a strong permeability into the base material, and conventional solvent or emulsion type release agents cannot provide a good release surface.

The main purpose of the present invention is to solve the above-mentioned problems, to enable easy coating even without a solvent if necessary, to cure quickly by irradiation with ionizing radiation, and to have good peelability. It is an object of the present invention to provide a release agent that provides a release agent layer with good printability even for water-based inks.

The ionizing radiation-curable release treatment agent of the present invention is
It was developed to achieve the above-mentioned purpose, and more specifically, for each equivalent of hydroxyl group in component A), a reactive group selected from a carboxyl group, an ethyleneimine ring, and an epoxy group in component B). 0.8
It consists of a terminal unsaturated group-containing modified organopolysiloxane which is a substantially complete reaction product between the following components A) and B) of ~1.2 equivalents, and is characterized by having printability.

A Organopolysiloxane represented by the following general formula (1) However, R ¹ and R ² are methyl group, ethyl group, and
propyl group or trifluoropropyl group,
x and y are each positive numbers, m is an integer from 0 to 4,
n is an average value in the range of 2 to 3; B An acrylate compound having a group reactive with the hydroxyl group of the organopolysiloxane selected from the following (a) to (c): (a) at least one group in one molecule; (b) An acrylate compound having an ethyleneimine ring represented by the following general formula (2) (R ³ in the formula is a hydrogen atom or has 1 to 4 carbon atoms.
(3) an acrylate compound having an epoxy group represented by the following general formula (3); k is an integer of 1 to 10) (R ⁴ in the formula represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and 1 represents 1 to 10
In other words, in the releasable treatment agent of the present invention,
Organopolysiloxane (component A) as the main component has a polyether part with high hydrophilicity and an organopolysiloxane part that imparts releasability in its structure, and is structured like a block, so it has excellent hydrophilicity and releasability. Provides a release agent layer with both properties. Further, the acrylate compound is bonded to the organopolysiloxane through a group reactive with the hydroxyl group of the organopolysiloxane, thereby imparting good curability to the reaction product by ionizing radiation, particularly electron beams.

The present invention will be explained in more detail below. In the following descriptions, "%" and "parts" indicate the composition.
are based on weight unless otherwise specified.

The organopolysiloxane which is the first main component of the releasable treatment agent of the present invention is represented by the above general formula (1), and the releasability can be controlled by the degree of polymerization y of the organopolysiloxane moiety. A range of 5 to 500, particularly 10 to 500 is preferably used. When the degree of polymerization y is less than 5, sufficient releasability cannot be obtained, and when it exceeds 500, printing suitability is slightly reduced. In addition, the polyether part (CnH _2o O) x is
If an alkylene oxide having the most important influence on the printing suitability of the resulting release agent layer and where n is 4 or more is used, the desired printing suitability cannot be obtained.
n can be a mixture of 2 and 3, but its average value is also 2 to 3, preferably in the range of 2 to 2.5, particularly in view of providing good printing suitability for water-based inks. The degree of polymerization x of the polyether part is related to the degree of polymerization of the organopolysiloxane part,
It is mainly determined to provide a good balance between the releasability and printability of the resulting release agent layer. That is, when the value of y/x becomes large and the organopolysiloxane portion becomes relatively large, the peeling force increases but the printing suitability deteriorates, and conversely, when the value of y/x becomes small and the polyether portion becomes small, the peeling force increases but the printing suitability deteriorates. , the printing suitability increases, but the peelability deteriorates. Therefore, a range of 0.5 to 10 is appropriate for y/x.

On the other hand, the total degree of polymerization of organopolysiloxane is 2x
+y affects the balance between releasability and printing suitability and curability. That is, if 2x+y is too small, releasability and printing suitability tend to deteriorate. If 2x+y is too large, the resulting release agent will not only have a high viscosity and poor coating suitability, but also will have poor curability and crosslinking properties, making it impossible to obtain a release agent layer with good film strength. Taking these points into consideration, x is preferably selected from the range of 2 to 100.

The alkylene moiety CmH _2n located between the organopolysiloxane moiety and the polyether moiety does not particularly need to exist, and in this case it has the advantage of being able to be produced at low cost, but if this alkylene moiety exists, the organopolysiloxane has the advantage of increased stability. However, organopolysiloxanes in which m is 5 or more have no particular advantage in terms of performance, but are disadvantageous in terms of raw material availability, so m is preferably 3 or 4, and most preferably 3.

Specific examples of organopolysiloxanes include the following.

On the other hand, the acrylate compound as component B has a group reactive with the hydroxyl group of the organopolysiloxane, and is classified into the following groups (a) to (c) depending on the type of the reactive group. Ru.

(a) Compounds having at least one carboxyl group in one molecule. Specifically, acrylic acid, methacrylic acid, 2
- an adduct of phthalic anhydride with any of hydroxyethyl methacrylate; or with glycicyl acrylate or glycicyl methacrylate;
Examples include reactants with dibasic acids such as itaconic acid, maleic acid, fumaric acid, succinic acid, acipic acid, and terephthalic acid.

(b) Acrylate compound having an ethyleneimine ring represented by the following general formula (2) (R ³ in the formula represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and k is an integer of 1 to 10.) Specifically, those represented by the following chemical formula are exemplified.

(c) Acrylate compound having an epoxy group represented by the following general formula (3) (R ⁴ in the formula is a hydrogen atom or has 1 carbon atom
(represents ~4 alkyl groups, where 1 is an integer of 1 to 10) Specific examples include glycicyl ester of acrylic acid or methacrylic acid.

The acrylate compound (component B)) having a group reactive with the hydroxyl group described above is approximately equivalent to the organopolysiloxane (component A)), that is, the amount of the acrylate compound (component B)) that has a group reactive with the hydroxyl group described above is approximately equivalent to that of the organopolysiloxane (component A)). It is used in an amount of 0.8 to 1.2 equivalents of reactive groups.

The reaction conditions for both of the above components differ slightly depending on the type of reactive group in the acrylate compound (component B). Examples of typical methods are as follows.

In the case of a carboxyl group, the dehydration condensation reaction with the hydroxyl group in the organopolysiloxane (component A) is carried out using mineral acids such as sulfuric acid and hydrochloric acid, organic acids such as aromatic sulfonic acids, or borofluoride etherate. This is done using a Lewis acid as a catalyst. Using a large excess of benzene and toluene as solvents, the water produced is separated by azeotropic distillation to allow the reaction to proceed.

In the case of the ethyleneimine ring, the ring-opening addition reaction with the hydroxyl group can be performed using sulfuric acid, _HBF4 ,
It is carried out in the presence of an acid catalyst such as HBF ₃ OR.

(c) In the case of an epoxy group, the ring-opening addition reaction with a hydroxyl group also proceeds by heating without a catalyst, but it is possible to accelerate the reaction by adding a catalyst. As the catalyst, an acid or a base is used, and usually inorganic bases and organic bases are mainly used. Examples of the inorganic base include potassium hydroxide and sodium hydroxide. Examples of the organic base include tertiary amines such as triethylamine and pyridine.

The stripping treatment agent of the present invention contains the above reaction product (acrylated organopolysiloxane) alone or in a mixture with other reactive monomers, solvents, pigments, fillers, and other additives. , can be used. As reactive monomers, acrylate monomers having unsaturated bonds, vinyl or allyl group-containing monomers can be used, for example, in the reaction products mentioned above.
Approximately 5 to 100 parts are used per 100 parts.

An example of the use of the releasable treatment agent of the present invention will be explained with reference to the accompanying drawings. As shown in a cross-sectional view in FIG. Preferably, the releasable treatment agent obtained as described above is
Apply at a rate of 0.1 to 5 g/m ² (solid content). If the coating amount is less than 0.1 g/m ² , the unevenness on the surface of the substrate will not be completely flattened, and therefore sufficient releasability will not be obtained. Moreover, even if it is applied in an amount exceeding 5 g/m ² , no further improvement in releasability can be expected and it becomes uneconomical. The coating method is basically arbitrary, and for example, methods such as roll coating, gravure coating, air knife coating, curtain flow coating, etc. are used. When coating a paper base material without a sealing layer, a release agent layer that hardly penetrates into the base material can be obtained by using a solvent-free release agent and hot-melt coating. In terms of coating suitability, it is desirable that the viscosity at the time of coating be 10,000 centistokes or less, and if necessary, the viscosity can be adjusted by adjusting the molecular weight of the above reaction product or diluting it with a reactive monomer as appropriate. .

After the releasable treatment agent 2 of the present invention is applied as described above, it is irradiated with ionizing radiation such as electron beams, gamma rays, x-rays, and short wavelength ultraviolet rays to be cured. For example, for electron beams, Kotscroft-Walton type,
Emitted from various electron beam accelerators such as Van de Graaff type, resonant transformer type, linear type, dynamitron type, high frequency type, etc., it is 50 to 1000 KeV, preferably 100 to
An electron beam with an energy in the range of 300 keV is used. Appropriate irradiation dose is about 0.5 to 10 Mrad.

Next, as shown in FIG. 2, on the release agent layer 2a obtained by curing, a printing pattern 3 is applied with ordinary oil-based or water-based ink as necessary,
A label roll as shown in FIG. 3 is obtained by forming an adhesive layer 4 on the back surface, making perforations 5 and winding it up. Further, as shown in FIG. 4, it is also possible to obtain a laminate of forms 6 with one end fixed with an adhesive 4. The label or form thus obtained has the feature that printing or writing can be easily done with not only oil-based ink but also water-based ink in the margin provided by the surface of the release agent 2a.

As described above, according to the present invention, the sealing layer is made of a reaction product of an organopolysiloxane having a polyether moiety and an acrylate compound having a group reactive with its hydroxyl group, and is easily made into a solvent-free type. It is easy to coat even on paper without paper, and cures quickly by irradiation with ionizing radiation to provide a release agent layer with good releasability and good printability even with water-based inks. A treatment agent is provided.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 0.1 per mole of organopolysiloxane represented by and organopolysiloxane as catalyst
% by weight of P-toluenesulfonic acid, plus 3% of the total amount
Two moles of acrylic acid was added to a mixture of twice the amount of toluene as a solvent, and the mixture was heated and stirred. Acrylated organopolysiloxane was obtained by continuing heating and stirring for 6 hours while separating the produced water by azeotropic distillation. Add hydroquinone to this stuff
A stripping treatment agent was obtained by adding 0.05% by weight.

The above releasable treatment agent was applied to high-quality paper (Daishowa Paper Co., Ltd. 55).
The coating amount is 0.5g/ ^m2 by roll coating method on Kg).
Coating is performed so that the
CB200/50/30), acceleration voltage 175KV,
It was cured by irradiating it with an electron beam at an irradiation dose of 3 Mrad. Furthermore, acrylic adhesive (manufactured by Toyo Ink) was applied in stripes on the non-peelable surface as shown in Figure 2.
BPS2411) was applied at a coating amount of 10 g/m ² . After doing this, printing was performed on the peeled surface using an ink containing a polyether binder as the main component, and a clear print was obtained.
The tensile speed (cm/min) was 10 g/cm, which was a good result. Further, although unwinding was carried out at a pulling speed of 100 m/min, no damage to the base material such as paper flakes occurred.

Example 2 1 mol of the same organopolysiloxane as in Example 1, 0.01% by weight of sulfuric acid as a catalyst, and 30% by weight of a solvent (methyl ethyl ketone) were added and mixed based on the organopolysiloxane. Set the liquid temperature to 70~
While keeping at 80℃ 2 mol of was added dropwise, and stirring was continued for an additional 5 hours after the addition to obtain an acrylated organopolysiloxane. Hydroquinone was added in an amount of 0.05% by weight to obtain a release agent.

The above releasable treatment agent was applied to high-quality paper (Daishowa Paper Co., Ltd. 55).
The coating amount is 0.5g/ ^m2 by roll coating method on Kg).
Coating is performed so that the
CB200/50/30), acceleration voltage 175KV,
It was cured by irradiating it with an electron beam at an irradiation dose of 3 Mrad.

Thereafter, in the same manner as in Example 1, application of adhesive to the non-peelable surface, printing on the peelable surface, and rewinding tests were performed, and similarly good results were obtained in all cases.

Example 3 1 mol of the same organopolysiloxane as in Example 1, 1% by weight of pyridine as a catalyst, and 30% by weight of a solvent (methyl ethyl ketone) were added and mixed based on the weight of the organopolysiloxane. 2 mol of glycidyl methacrylate was added dropwise while maintaining the liquid temperature at 70 to 80°C, and after the addition, stirring was continued for an additional 5 hours to obtain a methacrylated organopolysiloxane. Hydroquinone was added in an amount of 0.05% by weight to obtain a releasable treatment agent. This releasable treatment agent was coated on high-quality paper (55 kg manufactured by Daishowa Paper Industries) using a roll coating method so that the coating amount was 0.5 g/ ^m2 , and then an electron beam irradiation device (Electro Curtain CB200 manufactured by ESI) was used. /50/30)
The material was cured by irradiating it with an electron beam at an accelerating voltage of 175 KV and an irradiation dose of 3 Mrad. Thereafter, in the same manner as in Example 1, application of adhesive to the non-peelable surface, printing on the peelable surface, and rewinding tests were performed, and similarly good results were obtained in all cases.

Example 4 A release agent and treated paper were obtained in the same manner as in Example 1, except that an organopolysiloxane of the same molar value expressed by the following formula was used in place of the organopolysiloxane used in Example 1.

Thereafter, in the same manner as in Example 1, application of adhesive to the non-peelable surface, printing on the peelable surface, and rewinding tests were performed, and similarly good results were obtained in all cases.

[Brief explanation of drawings]

FIGS. 1 and 2 are schematic cross-sectional views in the thickness direction of a base material showing the process of applying the releasable treatment agent of the present invention to the base material, and FIGS. 3 and 4 illustrate the releasable treatment obtained, respectively. 1 is a conceptual perspective view of a product having a surface; FIG. DESCRIPTION OF SYMBOLS 1... Base material, 2... Peelability processing agent layer, 2a... Cured state thereof, 3... Normal printed pattern, 4... Adhesive layer, 5...
Perforation, 6... form.

Claims (1)

[Scope of Claims] 1 The following A) and B) consisting of 0.8 to 1.2 equivalents of reactive groups selected from the carboxyl group, ethyleneimine ring, and epoxy group of component B) per 1 equivalent of hydroxyl group of component A) An ionizing radiation-curable releasable processing agent comprising a modified organopolysiloxane containing a terminal unsaturated group, which is a substantially complete reaction product between components, and having printability. A Organopolysiloxane represented by the following general formula (1) However, R ¹ and R ² are methyl group, ethyl group, and
propyl group or trifluoropropyl group,
x and y are each positive numbers, m is an integer from 0 to 4,
n is an average value in the range of 2 to 3; B An acrylate compound having a group reactive with the hydroxyl group of the organopolysiloxane selected from the following (a) to (c): (a) at least one group in one molecule; (b) An acrylate compound having an ethyleneimine ring represented by the following general formula (2) (R ³ in the formula is a hydrogen atom or has 1 to 4 carbon atoms.
(3) an acrylate compound having an epoxy group represented by the following general formula (3); k is an integer of 1 to 10) (R ⁴ in the formula represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and 1 represents 1 to 10
integer).