JPH02298511A - Silicone-based release agent, tacky member and separator - Google Patents

Abstract

PURPOSE:To obtain the subject release agent, containing a copolymer composed of polymer blocks having a specific glass transition point and polyorganosiloxane blocks, epoxy-based monomer and specific catalyst and capable of providing films excellent in oil ink printability and balance between peeling and bonding. CONSTITUTION:The objective silicone-based release agent obtained by blending an A-B type or/and (A-B)nX type (n is the number of coupling; X is coupling agent residue) block copolymer composed of (A) polymer blocks having >=50 deg.C glass transition point and (B) polyorganosiloxane blocks having structural units expressed by the formula (R is 1-20C alkyl, cycloalkyl, aryl or aralkyl) with a monomer having an epoxy-based functional group (e.g. 3,4- epoxycyclohexylmethyl 3',4'-epoxycyclohexylcarbonate) and an onium salt-based curing catalyst (e.g. a sulfonium salt-based curing catalyst).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention uses a polysiloxane block copolymer having a polymer block with a glass transition point of 50° C. or higher, which improves oil-based ink printability, peeling and adhesion balance. The present invention relates to a silicone release agent that forms a film with excellent properties, and an adhesive member and a separator having such a film.

There is a need for a release agent that forms a printable film due to the prior art and the need for address writing and the like.

Conventionally, a silicone release agent that forms a film that is compatible with oil-based ink printing has been proposed by blending finely powdered silica or ethyl cellulose with a special polysiloxane (
Japanese Unexamined Patent Publication No. 59-126475, No. 59-14704
Publication No. 8).

However, the problem is that the curing property is poor, the balance between peeling and adhesion of the formed film to the adherend is poor, and the release agent needs to be prepared using an organic solvent to ensure the viscosity and homogeneity of the release agent. There was a point. The original purpose of treating adhesive tapes, separators, etc. with release agents is to make them easier to peel from the adhesive surface, so poor peel/adhesion balance that makes winding processing impossible is a fundamental requirement. This can also be said to be a lack of performance. Furthermore, in terms of environmental hygiene and fire safety, it is desirable to apply the coating without a solvent and avoid the use of organic solvents.

Regarding a silicone-based release agent that can be applied without a solvent, one in which an onium salt-based curing catalyst is blended with a polyorganosiloxane containing an epoxy functional component in the molecule has been proposed (Japanese Patent Laid-Open No. 56-38350). Publication No. 60-
47064). This also has the advantage of being able to be cured by ultraviolet rays and being energy saving and efficient in film formation.

However, the formed film has problems such as repelling oil-based ink, poor printability, and insufficient curing due to poor compatibility with the nium salt-based curing catalyst, and requires a lot of UV irradiation to cure to a practical level. There are problems in that a large amount is required, and even in that case, the peeling characteristics of the formed film tend to vary, and the adhesive surface to which it is adhered becomes contaminated, resulting in a decrease in adhesive strength.

The group to which the present inventors belong previously proposed a silicone-based release agent that did not overcome the above-mentioned problems (Japanese Patent Application No. 1983-235094). This uses a polyorcassilo yarn containing an epoxy functional component and a polyether/polymethylene component in the molecule, and has excellent UV curability, oil-ink printability, and is solvent-free. It can be coated.

The object of the present invention is to develop an ink composition that satisfies the two requirements of curing properties, solvent-free coating properties, etc., and is also excellent in printability with oil 1-inch ink.

Means for Solving the Problems The present invention overcomes the above problems by using a block copolymer consisting of a polymer block with a glass transition point of 5 [1'C or higher] and a polyorganosiloxane block. It is.

That is, the present invention provides a polymer block A1 having a glass transition point of 50°C or higher and a general formula: -+5I(R2)-〇F (where R is a carbon number of 1 to 20
is an alkyl group, cycloargyl group, aryl group, or aralkyl group. ) A-B type consisting of polyorganosiloxane block B having the structural unit represented by
and (A=B)nX type pro-tsuku copolymer (however,
Said above. is the coupling number and X is the coupling agent residue. ), a monomer having an epoxy functional group, and an onium salt curing catalyst; The present invention also provides an adhesive member having an adhesive layer on the other side, and a separator having a film made of the silicone release agent described above on one or both sides of a supporting base material.

Function: The above-mentioned block copolymer has excellent compatibility with monomers having epoxy functional groups based on the polymer block A, excellent adhesion to objects to be treated, and excellent wettability with oil-based inks. Also, based on polyorganosiloxane block B, it has excellent peeling performance. On the other hand, monomers having epoxy functional groups are UV curable or UV curable using onium salt curing catalysts.
It exhibits thermosetting properties, functions as a crosslinking agent and as a diluent, improves solvent-free coating properties, and also contributes to the wettability of oil-based inks.

As a result of the above, it is possible to apply solvent-free coating to form a film that has excellent stability and good curing properties, and has excellent peeling properties, non-staining of the adhesive surface, adhesive strength maintenance property, and oil-based ink printability.
A silicone release agent that is cured by ultraviolet light or heat is obtained.

Examples of Constituent Elements of the Invention The block copolymer used in the present invention is of the /1-B type or/and (A-B) consisting of a polymer block A and a polyorganosiloxane block B.

It is of type X (where . is the number of couplings and X is the residue of the coupling agent).

The polymer block A is formed of a polymer having a glass transition point of 50° C. or higher. Examples include monovinyl substituted aromatic polymers, polymethyl methacrylate, polycarbonates, polyesters, and the like. From the viewpoint of ease of synthesis, versatility, etc., monovinyl-substituted aromatic polymers containing styrene, methylstyrene, vinyltoluene, vinylxylene, etc. are preferred.

The molecular weight of the polymer block A is 3,000 to 300.000 based on the number average molecular weight in terms of polystyrene by GPC (gel permeation chromatography).
is appropriate. If the number average molecular weight is less than 3.000, the formed film will have poor adhesion to the object to be treated, and will tend to transfer to the adhesive surface to which it is adhered, reducing the adhesive strength. Poor miscibility with ingredients.

, 1 Polyorganosiloxane block B is
General formula +5i (R2) Consists of a structural unit represented by O+. In the formula, R is an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, or an aralkyl group. In view of ease of availability and peeling performance, those in which R is a methyl group are preferred.

The molecular weight of polyorganosiloxane block B is determined by GPC
1.0 based on the number average molecular weight of polystyrene equivalent
00 to 300,000 is appropriate. If the number average molecular weight is less than 1,000, the formed film will have poor peeling performance, and if it exceeds aoo or ooo, it will have poor miscibility with other components.

The composition ratio of polymer block A and polyorganosiloxane block B in the block copolymer is suitably 5 to 95% by weight based on A/B. If the composition ratio is less than 5% by weight, the formed film will have poor adhesion to the object to be treated, and if it exceeds 95% by weight, the formed film will have poor peeling performance.

The block copolymer used is one or more types of A-B
type or A-B) nX type, or a mixture thereof. The AB type block copolymer can be synthesized by, for example, a pinion anionic polymerization method. That is, this is a method in which a polymer to be a polymer block A is first formed using an organolithium such as butyllithium as an initiator, and then an organosiloxane is added to form a polyorganosiloxane block B on the polymer A. On the other hand, in the synthesis of the (A-B) nX type block copolymer, for example, an alkenyl group is introduced into the molecular terminal of the above-mentioned A-B type block copolymer using a halogenated alkenyl compound, and this is synthesized by Mi5i. A method of coupling by hydrosilylation with a silane or siloxane coupling agent having two or more -H groups, or a coupling agent having two or more halogen groups in the living active form of an A-B type block copolymer. This can be carried out by a method of coupling by causing the reaction to occur. In that case, it is appropriate that the number n of couplings of the 8-B type block copolymer unit be 2 to 6. If the number of couplings exceeds 6,
The resulting release agent has a high viscosity, making solvent-free coating difficult.

The monomer having an epoxy functional group used in the present invention is a compound having one or more epoxy functional groups. Examples are: ethylene glycol diglycidyl ether: glycerin diglycidyl ether: vinylcyclohexene dioxide.

Limonene dioxido 3.4-Epoxycyclohexylmethyl-3゛,4''-
Epoxycyclohexylcarboxylate.

Bis-(6-methyl-3,4-epoxycyclohexyl)adipate: etc.

The number of monomers having an epoxy functional group to be used may be one or two or more. The appropriate amount is 10 to 10,000 parts by weight, preferably 50 to 2,000 parts by weight, per 100 parts by weight of the block copolymer.

If the amount is less than 10 parts by weight, the resulting release agent will have a high viscosity, making solvent-free coating difficult, and if it exceeds 10,000 parts by weight, the formed film will have poor release performance.

In the present invention, known onium salt curing catalysts are used. Examples include the formula ArN2''Z-,
R3S'' Z-, R21+Z- (Ar is an aryl group, R is an alkyl group or an aryl group, Z- is BF4
, PFs, AsFe-,5bFe-1S
It is a non-basic, non-nucleophilic anion such as bC1e, H3O4-, ClO4-. ), diazonium salts, sulfonium salts, and iodonium salts are available.

The amount of onium salt-based curing catalyst to be blended is suitably 0.1 to 20% by weight, particularly preferably 0.5 to 10% by weight, based on the content in the resulting release agent. Its content is 0
．． If it is less than 1% by weight, the curability will be poor, and if it exceeds 20% by weight, the contribution will be poor, which is not preferable because the J1] release performance may be inhibited.

Note that in Section 1, a release agent that can be applied without a solvent has been described, but in the present invention, it can also be prepared as a solution type using a solvent, or as an aqueous or non-aqueous dispersion type. In that case, based on miscibility and viscosity (constraints on components to be used, etc. are relaxed, it is possible to select the components to be used and the blending ratio within a wider range. For example, polymer block A1 polyorkanosiloxane block B A block copolymer with a number average molecular weight of about 800,000 and a coupling number of up to about 20 (Δ
=B) It becomes possible to use an nX type block copolymer. Further, the amount of the monomer having an epoxy functional group can be reduced to about 1 part by weight per 100 parts by weight of the block copolymer.

The silicone release agent of the present invention can be prepared by a known method-1.
1 = applicable. Therefore, for example, a release agent of 0.01~
A film can be formed by applying Log/nf, especially 0.1 to 5 g/♂, drying the coated layer if necessary, and curing the coated layer.

The curing treatment can take a heat treatment method or an ultraviolet irradiation treatment method. A curing treatment method using ultraviolet irradiation is preferable from the viewpoints of energy saving, efficiency of film formation, and unrestricted application because the object to be treated does not require heat resistance. The curing treatment by ultraviolet irradiation can be performed using an appropriate ultraviolet source such as a high-pressure mercury lamp or a metal halide lamp. In addition, in the case of heat treatment method, 60 to 200
Heating temperatures of °C are common.

The silicone release agent of the present invention can be used, for example, in the formation of separators and in the back treatment of adhesive members such as adhesive tapes.
It is preferably used in applications where it is desired to be adhered to an adhesive surface and be easily peeled from the adhesive surface.

-121 The adhesive member of the present invention is one in which a film made of the above-mentioned release agent is provided on one side of a supporting base material, and an adhesive layer is provided on the other side.

In addition, the separator is one in which a darning film is provided on one or both sides of a supporting base material.

There are no particular limitations on the supporting base material to be used. In general,
Paper, plastic laminated paper, cloth, plastic laminated cloth, plastic film, metal foil, foam, etc. are used. The adhesive member may be formed by a known method such as applying an adhesive to the other surface of a supporting base material on which a film of a release agent has been previously provided.

Effects of the Invention The silicone release agent of the present invention has a glass transition point of 50°C.
It is composed of a polysiloxane block copolymer having the above polymer blocks, a monomer having an epoxy functional group, and an onium salt curing catalyst, so it is an ultraviolet curing type that can be applied without solvent. It has excellent curability.

Further, the formed film has good oil-based ink printability and has an excellent balance of peeling and adhesion to the adherend.

Examples Reference Example 1 200 parts of a 4.0 mmol benzene solution of 5ec-butyllithium (parts by weight, the same applies hereinafter) and 18 parts of purified styrene were placed in a reaction tank that was brought to a high vacuum using the break-seal method, and placed in an ice water bath. After stirring for 30 minutes to form a living polymer of styrene, 7.6 parts of purified hexamethylcyclotrisiloxane and 200 parts of purified tetrahydrofuran were added to the reaction solution, and the mixture was stirred at 20°C for 24 hours to form a living polymer of styrene. A polydimethylsiloxane block copolymer was obtained. Note that the living polymer was deactivated by introducing moisture.

As a result of GPC analysis and tH-NMR analysis of the above block copolymer, its number average molecular weight was 4500 for polystyrene block and 1900 for polydimethylsiloxane block.

Reference Example 2 0.48 parts of dimethylvinylchlorosilane was added dropwise to the living polymer-containing liquid of the polystyrene/polydimethylsiloxane block copolymer obtained according to Reference Example 1 to introduce a vinyl group at the terminal end. and the equivalent = si
1,1°3.3-tetramethyldisiloxane was added in a proportion to form -H groups, and in the presence of a platinum catalyst (1000 ppt
11) The mixture was stirred at 80° C. for 30 hours to perform coupling.

As a result, a polystyrene/polydimethylsiloxane/polystyrene block copolymer consisting of a polystyrene block having a number average molecular weight of 4,500 and a polydimethylsiloxane block having a number average molecular weight of 4,000 was obtained.

Reference Example 3 A polystyrene/polydimethylsiloxane block copolymer was prepared according to Reference Example 1 using 60 parts of purified styrene and 60 parts of purified hexamethylcyclotrisiloxane, and then coupled according to Reference Example 2. .

According to the above, 60 parts of a polystyrene/polydimethylsiloxane block copolymer consisting of a polystyrene block with a number average molecular weight of 15,000 and a polydimethylsiloxane block with a number average molecular weight of 15,000, and a number average molecular weight of 15,000
A mixture of 40 parts of a polystyrene/polydimethylsiloxane/polystyrene block copolymer consisting of 30,000 polystyrene blocks and 30,000 polydimethylsiloxane blocks was obtained.

Reference Example 4 Using the break-seal method, 500 parts of a 4.0 mmol benzene solution of 5ec-butyllithium and 120 parts of purified styrene were placed in a high vacuum reaction tank and stirred in an ice water bath for 30 minutes to dissolve the styrene. After forming a living polymer, 120 parts of purified hexamethylcyclotrisiloxane and 200 parts of purified tetrahydrofuran were added to the reaction solution, and the mixture was stirred at 20°C for 24 hours to prepare a polystyrene/polydimethylsiloxane block copolymer. ,
Coupling was carried out according to Reference Example 2.

As a result of the above, 80 parts of a polystyrene/polydimethylsiloxane block copolymer consisting of a polystyrene block with a number average molecular weight of aooooo and a polydimethylsiloxane block of 30,000, and a number average molecular weight of aooooo
A mixture of 20 parts of polystyrene/polydimethylsiloxane/polystyrene block copolymer consisting of 60,000 polystyrene blocks and 60,000 polydimethylsiloxane blocks was obtained.

Example 1 3.4-Epoxycyclohexylmethyl-3'.

4'-epoxycyclohexylnonorpoxylate 85
After adding 5 parts of a sulfonium salt-based curing catalyst and stirring, IO parts of the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 1 was added and mixed uniformly to form a solvent-free coating type. A release agent of the present invention was obtained.

The above release agent was coated with a squeeze coater to a thickness of 50 μII.
The coating amount is 1.1 on a polyester film of 1. Apply the coating so that it is Og/♂, and then use an ultraviolet irradiation device equipped with a high-pressure mercury lamp to irradiate the release agent-coated surface with 1 joule/cJ.
A separator was obtained by curing under the following irradiation conditions.

Example 2 A solvent-free coating type release agent of the present invention was obtained according to Example 1 using a heat-reactive sulfonium salt curing catalyst, and the coated layer was heated at 100°C for 10 minutes. I got a separator.

Example 3 Same as Example 1 except that the polystyrene/polydimethylsiloxane/polystyrene block copolymer obtained in Reference Example 2 was used instead of the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 1. A solvent-coated release agent of the present invention was obtained, and a separator was obtained using this.

Example 4 Instead of the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 1, the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 3 (=j-lac polymer and polystyrene/polydimethylsiloxane/polystyrene block copolymer) was used. A solvent-free coating type release agent of the present invention was obtained in the same manner as in Example 1, except that a mixture of polymers was used, and a separator was obtained using this.

Example 5 In place of the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 1, the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 4 and the polystyrene/polydimethylsiloxane/polystyrene block copolymer were used. A solvent-free coating type release agent of the present invention was obtained in accordance with Example 1 except that the mixture was used, and a separator was obtained using this.

Comparative Example 1 In place of the polystyrene/polydimethylsiloxane block copolymer obtained in Reference Example 1, a polymer with a number average molecular weight of 28,000 was used.
A solvent-free coating type release agent was obtained using polydimethylsiloxane according to Example 1, and a separator was obtained using this.

Comparative Example 2 Commercially available ultraviolet curable silicone release agent (X-62-7
296, manufactured by Shin-Etsu Chemical Co., Ltd.) to obtain a separator according to Example 1.

The following properties of the separators obtained in the evaluation test examples and comparative examples were investigated.

[Curability 1: ○ when there is no stickiness in the film formed on the separator]
, Low/, Some cases were evaluated as △, and other cases were evaluated as ×.

[Printability 1: Write letters on the surface of the formed film of the separator using a commercially available oil-based marker ink, and mark ○ if there is no popping or ◎ if it is particularly good.
), cases in which there was a slight degree were evaluated as △, and cases other than that were evaluated as ×.

"Adhesive Strength" At 20°C and 65% R and H, apply a commercially available adhesive tape (manufactured by Nitto Denko Corporation, Polyester Cheve No. 3, B) with a width of 19 mm to the formed film surface of the separator using a rubber roller weighing 2 kg. After crimping the adhesive tape back and forth once,
2 with a load of 70 g/c in the car V + 2
Leave at 0°C for 48 hours. After that, solve the load and
0°C, 65% R, +1, left for 2 hours, and the resulting product was wrapped with 300 m of adhesive tape using a shopper.
The sample was peeled off at a speed of 7 minutes (180° peel), and the force required for peeling was determined (average value of 4 samples).

[Residual adhesion rate] (Non-staining property of adhesive surface) After measuring the above adhesive strength, the adhesive tape was placed on a stainless steel plate (SUS27CP) with waterproof abrasive paper (280
A rubber roller weighing 2 kg was pressed onto the cleaned surface with one round stroke, and the force required for peeling was determined in the same manner as described above after leaving it for 30 minutes. Then, the ratio of the residual adhesive force of the obtained measurement value to the measurement value obtained for the adhesive tape that had not been brought into contact with the release agent film in the same manner as above was calculated as the residual adhesion rate (average of 4 samples). value).

The results are shown in the table. Note that Comparative Example 3 shows the characteristics of a polyester film that was not treated with a release agent.

As is clear from the table, the film made of the silicone release agent of the present invention has excellent oil-based ink printability and an excellent balance of release and adhesion to adherends such as adhesive surfaces.

Claims (1)

[Scope of Claims] 1. Polymer block A having a glass transition point of 50°C or higher, and general formula: -[Si(R_2)-O]- (wherein R is an alkyl group having 1 to 20 carbon atoms, cyclo A-B type or/and (A=B)_nX type block copolymer consisting of a polyorganosiloxane block B having a structural unit represented by an alkyl group, an aryl group, or an aralkyl group (however, A silicone release agent characterized in that it consists of a monomer having an epoxy functional group, and an onium salt curing catalyst. 2. The silicone release agent according to claim 1, wherein the (A-B)_nX type block copolymer used has a coupling number_n of 2 to 6. 3. An adhesive member comprising a support base material having a film made of the silicone release agent according to claim 1 on one side and an adhesive layer on the other side. 4. A separator comprising a film made of the silicone release agent according to claim 1 on one or both sides of a supporting base material.