JP2008156499A - Releasant composition for adhesive tape and release liner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a releasant composition for an adhesive tape used in e.g. electronic material applications or the like, excellent in releasability and non-migration tendency, and to provide a release liner using the above composition. <P>SOLUTION: The releasant composition for an adhesive tape comprises (A) an alkyd resin, (B) an amino resin and (C) a double-terminated reactive silicone resin containing functional groups reactive with these resins. For this releasant composition, the surface free energy of release layer is adjusted so as to be 18-23 mN/m. In this releasant composition, the component C is preferably an organopolydimethylsiloxane containing a hydroxy group modified with carbinol at both terminals. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention mainly relates to a release agent composition for a pressure-sensitive adhesive tape and a release liner, which are excellent in releasability and non-migration of silicone, which are used for adhesion of a cover material of an electronic device and various members inside the electronic device.

  Double-sided pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets are used in various industries because of their good handleability and good adhesive properties. Also in the electronic equipment field, many double-sided pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets are used for bonding various members. Conventional double-sided pressure-sensitive adhesive tapes and release liners for pressure-sensitive adhesive sheets are coated with a silicone composition having a small surface free energy in order to obtain good release properties. And when moving to the adhesive of adhesive sheets, and used in the field of electronic equipment, it becomes a cause of siloxane gas generation, which may cause corrosion inside the electronic equipment, malfunction, malfunction. There is a need for a release agent with less silicone migration in the release agent for double-sided tapes and adhesive sheets for this application.

  Further, as a release agent that does not use a silicone composition, a fluorine resin, an alkyd resin, a polyvinyl carbamate resin, and the like are known. However, the fluororesin has a low surface free energy like the silicone composition, but has a high elastic modulus, is insufficiently anchored with the base substrate and film, and is easy to fall off. When producing double-sided tape and adhesive sheets, a release liner Has a problem that it is likely to drop off when passing through a roll, and to cause defective release.

  On the other hand, although alkyd resins and polyvinyl carbamate resins are commercially available as non-silicone release agents that do not use silicone, acrylic adhesives with strong adhesive strength were used because of higher surface tension than silicone compositions. In some cases, peeling becomes extremely heavy and is not suitable for practical use.

As described above, the known release agents do not have release agents that sufficiently satisfy performance for electronic material applications.
Originally, alkyd release agents have good adhesion to paper and film substrates, and have been used as heavy release type release agents. In order to lighten the peeling, a technique of adding silicone oil has been known. However, although the peeling becomes light, the transfer of silicone to the pressure-sensitive adhesive layer is inevitable.

  There is a method of reducing the migration by using a reactive silicone composition as a means for suppressing these migrations and modifying it to an alkyd resin (Japanese Patent Laid-Open Nos. 2000-303018 and 2000-095929). Compared with the composition, the releasability was heavy, and it could not be used as a double-sided tape for electronic materials using an acrylic pressure-sensitive adhesive and a pressure-sensitive adhesive sheet.

JP 2000-303018 A JP 2000-095929 A

  The present invention solves the above-mentioned problems, has excellent releasability, and has a release agent composition for pressure-sensitive adhesive tapes used for double-sided pressure-sensitive adhesive tapes and pressure-sensitive adhesive sheets for electronic materials in which silicone migration substances are reduced as much as possible, and a release liner using the same Is to provide.

As a result of intensive investigations on the double-sided pressure-sensitive adhesive tape for electronic equipment and the release agent for pressure-sensitive adhesive sheet in consideration of the above-mentioned purpose, the both ends containing alkyd resin, amino resin, and functional groups having reactivity with these resins. A release agent composition comprising a carbinol-modified hydroxyl group-containing organopolydimethylsiloxane is effective in peelability and non-migration, and further contains both end-reactive functional groups represented by the following average composition formula (1). By controlling the degree of polymerization (n) of the siloxane (SiO) of the terminal carbinol-modified hydroxyl group-containing organopolydimethylsiloxane, the surface free energy of the release layer can be controlled, and the releasability is within the range of 30-100. It was found that an excellent release agent was obtained.
The present invention is [1] a release agent composition comprising an alkyd resin (A), an amino resin (B), a both-end reactive silicone resin (C) containing a functional group reactive with these resins, The release agent composition for pressure-sensitive adhesive tapes is adjusted so that the surface free energy of the release layer is 18 to 23 mN / m.
In the present invention, [2] The ratio (A / B) of the alkyd resin (A) to the amino resin is in the range of 90/10 to 40/60 in terms of the solid content weight ratio, and the total amount of these is 100 weight. The ratio ((A + B) / C) of the both-end reactive silicone resin (C) containing functional groups having reactivity with these resins to the parts is in the range of 100/1 to 100/20 in terms of solid content weight ratio. It is a release agent composition for adhesive tapes as described in said [1].
In addition, the present invention provides a both-end carbinol-modified hydroxyl group-containing organopolydimethylsiloxane in which the both-end reactive silicone resin (C) containing a functional group having reactivity [3] is represented by the following general formula (1): The release agent composition for pressure-sensitive adhesive tapes according to [1] or [2] above, wherein the degree of polymerization (n) of the siloxane represented by SiO is in the range of 30-100.

また、本発明は、［４］上記［１］ないし上記［３］のいずれかに記載の粘着テープ用剥離剤組成物を紙またはフィルム基材に塗工してなる剥離ライナーである。

The present invention also provides a release liner obtained by applying [4] a release agent composition for an adhesive tape according to any one of [1] to [3] above to a paper or film substrate.

  According to the present invention, it is possible to obtain a pressure-sensitive adhesive tape composition having excellent releasability and less migration, and a release liner using the same, and silicone migration is extremely small due to modification with an alkyd resin. Application to adhesive tapes and adhesive sheets is possible.

  The present invention is a release agent composition comprising an alkyd resin (A), an amino resin (B), and a both-end reactive silicone resin (C) containing a functional group reactive with these resins, and the surface of the release layer The present invention relates to a release agent composition for pressure-sensitive adhesive tapes that is adjusted so that the free energy is 18 to 23 mN / m.

  The alkyd resin (A) constituting the composition of the present invention may be a known one. For example, the oil length of alkyd resin is 0-65, preferably 35-55, acid value 1-30, preferably 5-25, hydroxyl value 50-300, preferably 100-250. What was manufactured using saturated fatty acid etc. is used, and what uses coconut oil fatty acid is especially preferable. In addition, it is also possible to use these alkyd resins modified or mixed with acrylic resin, polyester resin, epoxy resin, phenol resin or the like.

  The amino resin (B) constituting the composition of the present invention may be a known one. Examples thereof include a methylated melamine resin, a butylated melamine resin, a methylated urea resin, a butylated urea resin, a methylated benzoguanamine resin, and a butylated benzoguanamine resin, and these can be used alone or in combination. Especially, it is preferable from a peelable point to have methylated melamine resin as a main component.

  In the present invention, the ratio (A / B) of the alkyd resin (A) to the amino resin (B) is preferably a ratio of 90/10 to 40/60 in terms of solid content weight ratio. If it is this range, all of peeling force, non-migration, and sclerosis | hardenability can be satisfied. When the ratio exceeds 90/10, a sufficient cross-linked structure cannot be obtained in the release layer, resulting in a decrease in peel force and a tendency to transfer. On the other hand, when the ratio is less than 40/60, the release layer becomes hard and brittle, and the release layer is difficult to peel, and the release layer tends to be easily broken.

  The both-end reactive silicone resin (C) containing a reactive functional group constituting the composition of the present invention needs to contain a functional group reactive with the above-mentioned alkyd resin and / or amino resin. . This suppresses the migration of the silicone resin to the adhesive layer by adopting a structure in which the alkyd resin and amino resin forming the release layer and the silicone resin as the release component are chemically bonded in the release layer. This is because heavy peeling at the time of tape storage and a decrease in adhesive strength at the time of use can be prevented. Examples of the functional group include hydroxyl groups, amino groups, carboxyl groups, glycidyl groups and other alkyd resins and / or those reactive with amino resins, and it is necessary to contain at least two in one molecule. The functional group having reactivity with the alkyd resin and / or amino resin is most preferably a hydroxyl group.

  The both-end reactive silicone resin containing a hydroxyl group is reactive with alkyd, and the both ends represented by the general formula (1) are obtained as the object of the present invention to obtain a release sheet having good release properties. Examples include carbinol-modified silicone. This double-end reactive silicone resin is excellent in reactivity with the above-described alkyd resin and amino resin.

  This silicone resin needs to have a surface free energy in the range of 18 to 23 mN / m for the purpose of imparting light release properties to the release agent composition of the present invention. It is desirable that the repeating unit (n) of the siloxane of the resin is 30 to 100, more preferably 40 to 80. When the degree of polymerization is less than 30, the surface free energy is increased, the intended peelability is not exhibited, and there is a tendency for heavy peeling. Moreover, if it exceeds 100, the compatibility with the alkyd resin is extremely reduced and separated, and the denaturation reaction with the alkyd resin is hindered, so that it does not become a transparent film when coated on the film, and the silicone migration does not occur. It tends to be large and not exhibit performance as a release agent.

  In the present invention, the ratio ((A + B) / (C)) of the alkyd resin (A) and amino resin (B) to the both-end reactive silicone resin (C) described above is 100/1 to 100 / A ratio of 20 is desirable. If it is this range, all of peeling force and non-migration can be satisfied. If it is less than 100/1, sufficient peeling force cannot be obtained, and if it exceeds 100/20, the reactivity decreases, unreacted substances remain, and the adhesive layer may be contaminated due to migration of silicone. .

  The release agent composition for pressure-sensitive adhesive tapes of the present invention can form a release layer by applying to a substrate and heating and drying and curing. The heating temperature is usually 100 to 160 ° C. An acidic catalyst can also be used as a curing accelerator during dry curing. For this, known materials such as para-toluenesulfonic acid and hydrochloric acid which are usually used as a curing catalyst when the alkyd resin and the amino resin are subjected to a crosslinking reaction can be used.

  In this invention, the peeling agent composition for adhesive tapes can be obtained by mixing or reacting the predetermined amount of each above-mentioned component. In addition to the co-condensation reaction of alkyd resin, amino resin, and both-end reactive silicone resin, alkyd resin and silicone resin are bonded via urethane bond with diisocyanate, and then amino resin is mixed or co-condensed. You can also get it.

  In addition, this composition is usually an organic solvent solution for convenience of use, but as this organic solvent, a conventionally known one is used as long as it has good solubility with each component and does not have reactivity. be able to. For example, toluene, xylene, methanol, ethanol, isobutanol, n-butanol, methyl ethyl ketone, or a mixture of two or more thereof can be used, and the amount used is in the range of 10 to 60% by weight of resin solids. It is desirable to do so.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Further, “parts” and “%” shown in the examples indicate parts by weight and% by weight unless otherwise specified. The performance evaluation of the adhesive tape was performed according to the following method.

  1) Surface free energy: Contact angle meter CA-X (manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the contact angles of water, ethylene glycol and methylene iodide, and surface free energy analysis software EG-2 (Kyowa) Calculated using Interface Science Co., Ltd.

  2) Initial peeling force: Polyester adhesive tape Nitto 31B (product name, manufactured by Nitto Denko Corporation) was reciprocally pressed with a 2 kg roller on the produced release film, cut to a width of 25 mm, and 180 ° at a speed of 300 mm / min. The peel strength was measured.

3) Initial residual adhesion rate: The tape test piece subjected to the measurement in 2) was reciprocally pressed on a stainless steel plate with a 2 kg roller and pulled at 180 ° at a speed of 300 mm / min, and the peeling force W (g / 25 mm) was obtained. It was measured. On the other hand, a polyester adhesive tape without the above-described processing adhered to a stainless steel plate, which measures the force W ₀ (g / 25 mm width) required to peel from the stainless steel plate under the same conditions as above, W for the W ₀ The ratio (W / W ₀ ) (percentage) was determined as the initial residual adhesion rate.

  4) Accelerated peeling force: Polyester adhesive tape, Nitto 31B (product name, manufactured by Nitto Denko Corporation) was reciprocated with a 2 kg roller on the produced release film, and stored for 24 hours in an atmosphere of 65 ° C. and 80% RH. Thereafter, the film was cut to a width of 25 mm, pulled at 180 ° at a speed of 300 mm / min, and the peeling force was measured.

5) Residual adhesion rate: The tape test piece used for the measurement in 4) was pressed once on a stainless steel plate with a 2 kg roller, pulled at 180 ° at a speed of 300 mm / min, and the peeling force W (g / 25 mm) was measured. did. On the other hand, a polyester adhesive tape without the above-described processing adhered to a stainless steel plate, which measures the force W ₀ (g / 25 mm width) required to peel from the stainless steel plate under the same conditions as above, W for the W ₀ The ratio (W / W ₀ ) (percentage) was determined as the residual adhesion rate.

6) Non-migrating: A predetermined amount of the composition is applied to the surface of the sheet-like base material, and heat-treated at a predetermined temperature (150 ° C.) for a predetermined time (30 seconds) using a hot air circulating dryer to form a cured film. After forming, a 25 μm polyethylene terephthalate (PET) film was bonded to the surface of the film and held at a pressure of 10 kg / cm ² for 1 day, and then a wide magic was applied to the silicone contact surface of the PET film to observe the ink repelling condition. . Rejected items were evaluated as “×”, non-repellent items as “◯”, and slightly repelled items as “△”.
7) Film appearance: The appearance of the produced release film was visually observed. The transparent one was judged as “◯”, the one with slightly fogging as “Δ”, and the white cloudy as “×”.

[Example 1]
70 parts of palm oil modified alkyd resin Teslac 2052-60 (trade name, manufactured by Hitachi Chemical Polymer Co., Ltd.), 5 parts of both ends carbinol modified siloxane FM-4421 (trade name, manufactured by Chisso Corporation, degree of polymerization 62), methylated Add 30 parts of melamine resin Cymel 303 (trade name of Nippon Cytec Co., Ltd.) and 5 parts of 50% by weight para-toluenesulfonic acid methanol solution and dilute with toluene to make the solid content 30% by weight. Then, a release agent composition for pressure-sensitive adhesive tapes was obtained. Next, this solution was applied to a 50 μm thick PET film so as to have a film thickness of 1 μm, and dried and cured in a hot air drier at 150 ° C. for 30 seconds to prepare a release liner. At this time, the surface free energy of the release layer was 22.1 mN / m.

[Example 2]
Castor oil-modified alkyd resin Teslac 2002-60 (trade name, manufactured by Hitachi Chemical Polymer Co., Ltd.), Carbinol-modified silicone KF-6003 (trade name, degree of polymerization 71 manufactured by Shin-Etsu Chemical Co., Ltd.) 5 parts, methyl 25 parts of melamine resin Cymel 303 (trade name of Nippon Cytec Co., Ltd.), 5 parts of butylated urea melamine resin Tesazine 3103-60 (manufactured by Hitachi Chemical Co., Ltd.), and 5 parts of 50% by weight paratoluenesulfonic acid methanol solution Was added and diluted with toluene so as to have a solid content of 30% by weight to obtain a release agent composition for an adhesive tape. Next, a release liner was produced in the same manner as in Example 1. At this time, the surface free energy of the release layer was 21.3 mN / m.

[Comparative Example 1]
A release liner was prepared in the same manner as in Example 1 except that the silicone resin of Example 1 was changed to FZ3711 (trade name, Carbinol-modified silicone with a degree of polymerization of 22 at both ends of Toray Dow Corning Silicone Co., Ltd.). At this time, the surface free energy of the release layer was 23.4 mN / m.

[Comparative Example 2]
A release liner was prepared in the same manner as in Example 1 except that the silicone resin of Example 1 was changed to Silaplane FM-0425 (trade name of Chisso Corporation, both ends carbinol-modified silicone, degree of polymerization 130). At this time, the surface free energy of the release layer was 17.8 mN / m.

[Comparative Example 3]
A release liner was prepared in the same manner as in Example 2 except that the silicone resin of Example 1 was changed to dimethyl silicone oil SH200 (trade name, Toray Dow Corning Co., Ltd., dimethylpolysiloxane). At this time, the surface free energy of the release layer was 19.4 mN / m.

  The evaluation results of Examples 1-2 and Comparative Examples 1-3 are shown in Table 1.

From these tables, it can be seen that the release liner composition for release liner of the present invention is excellent in peelability and residual adhesiveness and non-migrating.
According to the present invention, it is possible to obtain a release agent composition for an adhesive tape having excellent releasability and less migration, and a release liner using the same. Application to double-sided adhesive tapes and adhesive sheets for materials becomes possible.

Claims (4)

A release agent composition comprising an alkyd resin (A), an amino resin (B), and a both-end reactive silicone resin (C) containing a functional group reactive with these resins, wherein the surface free energy of the release layer is The release agent composition for adhesive tapes adjusted so that it may become 18-23 mN / m. The ratio (A / B) of the alkyd resin (A) to the amino resin is in the range of 90/10 to 40/60 in terms of the solid content weight ratio, and these resins react with the total amount of 100 parts by weight. 2. The pressure-sensitive adhesive according to claim 1, wherein the ratio ((A + B) / C) of the both-end reactive silicone resin (C) containing a functional group having a property is in a range of 100/1 to 100/20 in terms of solid content weight ratio. Tape release agent composition. The both-end reactive silicone resin (C) containing a functional group having reactivity is a carbinol-modified hydroxyl group-containing organopolydimethylsiloxane represented by the following general formula (1): The release agent composition for pressure-sensitive adhesive tapes according to claim 1 or 2, wherein the degree of polymerization (n) is in the range of 30 to 100.

A release liner obtained by applying the release agent composition for an adhesive tape according to any one of claims 1 to 3 to paper or a film substrate.