KR20080057127A - Addition reaction type silicone based release agent composition and release film - Google Patents

Abstract

An addition type silicone-type release agent composition is provided to realize excellent release property and adhesion between a release layer and a substrate. An addition type silicone-type release agent composition comprises: an addition type silicone resin; and an organosiloxane oligomer containing an organosiloxane backbone and having alkenyl groups on a side chain, or a side chain and the backbone, wherein the molar ratio of number of alkenyl groups contained in the composition to the number of methyl groups contained in the composition is 0.02-0.08.

Description

Addition reaction type silicone based release agent composition and release film

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram for demonstrating the measuring method of the peeling force rise rate after a school trip.

[Description of the code]

10 release film

20 adhesive sheets

30 adhesive

W1 polishing part

W2 non-abrasive part

The present invention relates to an addition-reactive silicone type release agent composition which suppresses the release of the release agent from the substrate and has excellent peeling performance, and a release film using the same.

A release film is used for adhesive protection of an adhesive product, etc., For example, for manufacturing LCD structural members, such as a liquid crystal polarizing plate or a retardation plate, for manufacturing PDP structural members, for manufacturing various other display structural members, or other various optical members, Or a wide range of fields, such as for manufacturing ceramic green sheets or for forming protective layers and information recording layers of optical recording media. In general, the release film is formed by laminating a release agent layer on a base material such as a polymer film, and a silicone resin is widely used as the material of the release agent layer. However, the release agent layer composed of the silicone resin is inferior in adhesion to the base material and falls off from the base material. There is a case.

Conventionally, in order to improve the adhesiveness of the release agent layer to the substrate, as described in JP-A-64-5838, before the release layer is laminated on the substrate, the surface of the substrate is coated with a silane coupling agent. A method of making this is proposed. However, according to this method, the coating process of a silane coupling agent must be added, and it raises a cost, and also raises a problem that a part of silane coupling agent evaporates and accumulates in a manufacturing apparatus etc. during manufacture.

In addition, Japanese Patent Laid-Open No. 62-2986 discloses that a release agent composition composed of a crosslinkable silicone and a silane coupling agent is used to form a release agent layer in order to improve adhesion. Japanese Laid-Open Patent Publication No. 2003-26925 discloses a release agent composition comprising a branched organopolysiloxane and an addition reaction type silicone resin.

However, the release agent compositions disclosed in Japanese Patent Application Laid-Open No. 62-2986 and Japanese Laid-Open Patent Publication No. 2003-26925 can improve the adhesion to the substrate, but the peeling force on the adhesive tends to be heavy. There is a problem that good peelability cannot be obtained.

Then, this invention is made | formed in view of the said problem, and an object of this invention is to provide the peeling agent composition which can improve peeling performance and can make adhesiveness with respect to the base material of a peeling agent layer favorable.

The addition reaction type silicone release agent composition according to the present invention is an addition reaction type containing an addition reaction type silicone resin and a branched organosiloxane oligomer having a side chain containing an organosiloxane skeleton or an alkenyl group in the side chain and the main chain. In the silicone-based release agent composition, the number of alkenyl groups included in the composition is 0.2 to 0.08 (molar ratio) with respect to the number of methyl groups included in the composition.

At this time, in the branched organosiloxane oligomer, the number of alkenyl groups is preferably 0.2 to 0.5 (molar ratio) relative to the number of methyl groups. Moreover, in the peeling film which concerns on this invention, the cured film of the addition reaction type silicone type peeling agent composition mentioned above is formed in at least one surface of the base material.

The addition reaction type silicone release agent composition according to one embodiment of the present invention contains an addition reaction type silicone resin, a branched organosiloxane oligomer, a crosslinking agent, and a catalyst, and, as desired, an addition reaction inhibitor, a peeling regulator, and adhesion. An improver etc. may be added. In addition, when performing ultraviolet irradiation in addition to heating at the hardening process after peeling agent application | coating, the photoinitiator may be added.

As addition reaction type silicone, it is conventionally used as a conventional thermosetting silicone resin releasing agent, can be used without a restriction | limiting, For example, at least 1 sort (s) chosen from the polyorganosiloxane which has at least 2 alkenyl groups as a functional group in 1 molecule. Can be used. Here, as the alkenyl group, for example, vinyl group (ethenyl group), allyl group (2-propenyl group), butenyl group, pentenyl group, hexenyl group, heptenyl group, octenyl group, de Cenyl group etc. are mentioned. Alkenyl group may be contained as a structural unit of a principal chain, or may be contained as a structural unit of a side chain.

As said polyorganosiloxane, the linear polyorganosiloxane etc. which have at least 2 alkenyl group in 1 molecule of Formula (1) are mentioned.

In Formula 1 above,

R is the same or different monovalent hydrocarbon group containing no aliphatic unsaturated bonds,

R ¹ is an alkenyl group,

n is 1000 to 5000,

a is 1 to 3,

b is 1 to 3,

n, a and b are integers.

R in the general formula (1) is preferably a monovalent hydrocarbon group having 1 to 12 carbon atoms, particularly 1 to 10 carbon atoms, and for example, aryl groups such as alkyl groups such as methyl group, ethyl group and propyl group, phenyl group and tolyl group. And the like. Examples of the alkenyl group represented by R ¹ in the general formula (1) include those having 2 to 10 carbon atoms such as vinyl group, allyl group, propenyl group, hexenyl group, octenyl group, and decenyl group.

In the said polyorganosiloxane, it is preferable that 80 mol% or more is a methyl group among monovalent hydrocarbon groups couple | bonded with the silicon atom directly, for example, in formula (1), it is preferable that 80 mol% or more of R is a methyl group. .

Specific examples of the polyorganosiloxane having at least two alkenyl groups as functional groups in one molecule include polydimethylsiloxane having a vinyl group as a functional group, polydimethylsiloxane having a hexenyl group as a functional group, and mixtures thereof.

As the branched organosiloxane oligomer, a branched organosiloxane oligomer in which an organosiloxane oligomer is used as a main chain and a side chain containing an organosiloxane skeleton branches from the main chain is used. Branched organosiloxane oligomers have alkenyl groups in the side chain, or in the side chain and the main chain, which comprise the organosiloxane skeleton. The side chain containing the organosiloxane skeleton is branched from one or two or more from the main chain, but at least one side chain may have an alkenyl group. The branched organosiloxane oligomer may be a star oligomer having one side chain containing an organosiloxane skeleton, or any of comb oligomers having two or more.

A branched organosiloxane oligomer is represented by following formula (2), for example.

In Formula 2 above,

R ⁴ represents a monovalent hydrocarbon group, but at least two of all R ⁴ are alkenyl groups such as vinyl groups, and 80 mol% of the monovalent hydrocarbon groups of R ⁴ are preferably methyl groups. In addition, t is 1-15, and q, r, s, t is the number which makes the number average molecular weight (Mn) of a branched organosiloxane oligomer into 500 to 5000.

In the branched organosiloxane oligomer, the number of alkenyl groups is preferably 0.2 to 0.5 (molar ratio) relative to the number of methyl groups. The molar ratio can be obtained from the peak area of the spectrum obtained by analyzing the branched organosiloxane oligomer on ¹ H-NMR.

The branched organosiloxane oligomer is added in the release agent composition such that the number of alkenyl groups is 0.02 to 0.08 (molar ratio) relative to the number of methyl groups. This molar ratio can be obtained from the peak area of the spectrum obtained by analyzing the release agent composition on ¹ H-NMR. When the molar ratio is less than 0.02, the film strength may be insufficient, and the release agent may easily drop off from the substrate. When the molar ratio exceeds 0.08, the crosslinking density of the coating film formed by the release agent composition is high, and the peeling force is heavy. The peeling performance may deteriorate.

The above-mentioned addition-reaction type silicone can form a film having a relatively high number average molecular weight and good peeling force, but when used alone, the film has insufficient film strength and inferior adhesion to the substrate. In this embodiment, peeling force is made favorable by adding the said branched organosiloxane oligomer with a relatively low number average molecular weight so that the number of alkenyl groups may be a specific ratio, The peeling agent layer which has high adhesiveness with respect to the base material of a peeling agent is added. It is possible to form.

As the crosslinking agent, for example, a polyorganohydrogensiloxane having at least two silicon atom-bonded hydrogen atoms in one molecule, specifically, a dimethylhydrogensiloxy group terminal blockade dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy Group terminal blockade dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group terminal blockade poly (methylhydrogensiloxane), poly (hydrogensilsesquioxane) and the like. In this embodiment, a cured film is formed by addition reaction of SiH of a crosslinking agent, an addition reaction type silicone resin, and the alkenyl group of branched organosiloxane oligomer.

The crosslinking agent is preferably added in the release agent composition such that the number of silicon atom-bonded hydrogen atoms becomes 0.8 to 5.0 (molar ratio) with respect to the number of alkenyl groups. Such molar ratio can be calculated | required from the peak area of the spectrum obtained by analyzing a peeling agent composition by <^1> H-NMR. If the molar ratio is less than 0.8, the curability of the composition is lowered. If the molar ratio is larger than 5.0, the peeling force of the release agent becomes heavy and the peeling performance may deteriorate.

As the catalyst, for example, a platinum-based compound is used. Examples of the platinum-based compound include particulate platinum, particulate platinum adsorbed on a carbon powder carrier, platinum chloride, alcohol-modified platinum chloride, olefin complex of platinum chloride, palladium, rhodium. A catalyst etc. are mentioned. The catalyst is added in an amount of about 1 to 1000 ppm as the platinum-based metal to the total amount of the addition reaction type silicone resin and the crosslinking agent.

The release agent composition which concerns on this embodiment is mix | blended with the organic solvent, for example, the solution of a release agent composition is apply | coated to the base material which consists of a polymer film, etc., and it hardens | cures by this, and the cured film of the said composition is carried out on one side of a base material by this, A release film formed as a layer is obtained. Although the said hardening is performed by thermosetting, ultraviolet irradiation may be made in addition to heating in a hardening process. The release film may further comprise a pressure-sensitive adhesive layer and a base material on the pressure-sensitive adhesive layer side in this order on the release layer thereof.

In addition, in this specification, number average molecular weight (Mn) means what calculated | required each silicone resin by gel permeation chromatography (GPC) which uses tetrahydrofuran as a developing solvent, and calculated | required it as polystyrene conversion value. Measurement conditions are as follows.

GPC measuring device: HLC-8020 (trade name, manufactured by Tosoh Corporation)

GPC column (passed in the following order): TSK guard column HXL-H, TSK gel GMHXL (× 2), TSK gel G200OHXL (trade name, manufactured by Tosoh Corporation)

Measuring solvent: tetrahydrofuran

Measuring temperature: 40 ℃

In addition, ¹ H-NMR analyzes under the following conditions.

Measuring instrument: AVENCE500 [trade name, Bruker BI0SPIN], 500 MHz

Measuring solvent: heavy chloroform

Measuring temperature: 23 ℃

EXAMPLE

Although this embodiment is demonstrated using a following example, this invention is not limited to the structure of the following example.

Example 1

100 mass% of solid content to 100 mass parts (30 mass parts as solid content) of addition reaction type silicone resin solution (brand name: KS-3656A, Shin-Etsu Chemical Co., Ltd. make, containing polyorganohydrogensiloxane as a crosslinking agent) of 30 mass% of solid content. The branched organosiloxane oligomer (brand name: X62-1387, manufactured by Shin-Etsu Chemical Co., Ltd., containing polyorganohydrogensiloxane as a crosslinking agent) was added, and diluted with toluene solvent so that solid content concentration might be 1.0 mass%. A platinum catalyst (trade name: PL-50T, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to this diluted solution at a ratio of 1 part by mass to obtain a solution of the release agent composition. The solution of the release agent composition was applied on a PET film base material (trade name: T-100, manufactured by Mitsubishi Polyester Film Co., Ltd.) having a thickness of 38 μm so that the film thickness after drying was 0.1 μm, and then dried at 150 ° C. for 30 seconds to provide a solution on the base material. The release film in which the release agent layer was laminated | stacked was obtained.

In addition, ¹ H-NMR analysis was performed about KS-3656A, X62-1387, and a peeling agent composition, and the molar ratio was calculated | required as follows from the peak intensity of the spectrum. That is, in KS-3656A, the number of alkenyl groups relative to the number of methyl groups was 0.019 (molar ratio). In X62-1387, the alkenyl group was 0.31 (molar ratio) relative to the number of methyl groups. In the release agent composition (except for the solvent), the alkenyl group is 0.045 (molar ratio) to the number of methyl groups, while the number of silicon atom-bonded hydrogen atoms is 1.8 (molar ratio to the number of alkenyl groups). Was. In this example, the alkenyl group was a vinyl group. In addition, when the number average molecular weights (Mn) of KS-3656A and X62-1387 were measured, respectively, they were 197000 and 1090, respectively.

Example 2

A release film was obtained in the same manner as in Example 1 except that the film thickness after drying of the release agent layer was 1 μm.

Example 3

Except that the addition amount of X62-1387 (branched organosiloxane oligomer) was 5 mass parts with respect to 100 mass parts (30 mass parts as solid content) of KS-3656A (addition reaction type silicone resin solution), A release film was obtained in the same manner as in 1. At this time, as a result of ¹ H-NMR analysis of the release agent composition, the alkenyl group relative to the number of methyl groups in the release agent composition (excluding the solvent) was 0.031 (molar ratio) and silicon atom bonding. The number of hydrogen atoms was 1.8 (molar ratio) with respect to the number of alkenyl groups.

Example 4

Except that the addition amount of X62-1387 (branched organosiloxane oligomer) was 20 mass parts with respect to 100 mass parts (30 mass parts as solid content) of KS-3656A (addition reaction type silicone resin solution). A release film was obtained in the same manner as in 1. At this time, as a result of ¹ H-NMR analysis of the release agent composition, the alkenyl group relative to the number of methyl groups in the release agent composition (excluding the solvent) was 0.074 (molar ratio) and silicon atom bonding. The number of hydrogen atoms was 1.8 (molar ratio) relative to the number of alkenyl groups.

Comparative Example 1

Example 1 Except that X62-1387 (branched organosiloxane oligomer) was added in an amount of 0.05 parts by mass based on 100 parts by mass of KS-3656A (added reaction type silicone resin solution) (30 parts by mass as a solid). A release film was obtained in the same manner. At this time, as a result of ¹ H-NMR analysis of the release agent composition, the alkenyl group relative to the number of methyl groups in the release agent composition (excluding the solvent) was 0.017 (molar ratio) and a silicon atom-bonded hydrogen atom. The number of was 1.9 (molar ratio) relative to the number of alkenyl groups.

Comparative Example 2

Example 1 Except that X62-1387 (branched organosiloxane oligomer) was added in an amount of 30 parts by mass with respect to 100 parts by mass (30 parts by mass as a solid) of KS-3656A (additional-type silicone resin solution). A release film was obtained in the same manner. At this time, as a result of ¹ H-NMR analysis of the release agent composition, the alkenyl group relative to the number of methyl groups in the release agent composition (excluding the solvent) was 10.10 (molar ratio) and silicon atom bonds. The number of hydrogen atoms was 1.8 (molar ratio) relative to the number of alkenyl groups.

(1) initial peeling force

An acrylic pressure-sensitive adhesive (trade name: BPS-5127, manufactured by Toyo Inky Industries Co., Ltd.) was applied at a coating amount of 24 g / m 2 on the surface on which the release agent layer of each release film was coated, to form an adhesive layer. Subsequently, a 50-micrometer-thick PET film (trade name: Lumira E20 # 50, manufactured by Toray Corporation) was stacked on the pressure-sensitive adhesive layer as a base material on the pressure-sensitive adhesive layer side, and then a 2 kg roller was reciprocated once and pasted to obtain an adhesive. The adhesive was left to stand for 1 day under the conditions of the temperature of 23 degreeC, and 50% of humidity. Thereafter, the pressure-sensitive adhesive had a width of 20 mm, and the substrate on the pressure-sensitive adhesive layer side was 180 ° using a universal tensile tester (trade name: TENSILON UTM-4-100, manufactured by Orientec) under conditions of a temperature of 23 ° C. and a humidity of 50%. It peeled at the speed | rate of 300 mm / min in the direction of, and the peeling force at this time was measured. In addition, the peeling force of 50 mN / 20mm or less was made into O in Table 1 because peeling force is favorable, and the peeling force exceeding 50mN / 20mm was made into X in Table 1 because peeling force is too heavy.

(2) Rate of peeling force after school

The peeling film was stored for 1 day under conditions of 40 degreeC and 80% of humidity, and it grind | polished using the friction fastness tester (brand name: RT-200, the product made by Oega Chemical Co., Ltd.). Specifically, the CPP80 film (trade name: Aroma AE-U, Showa Denko Co., Ltd.) as a polishing piece was reciprocated 10 times under a load of 200 g to polish the release agent layer side, and as shown in FIG. 1, the release film 10 The straight polishing part W1 was provided in the center part of ().

Next, an adhesive sheet 20 having a width of 20 mm was superimposed on the release film 10 so that the adhesive face was in contact with the release agent layer side, and the 2 kg roller was reciprocated 10 times to stick them to obtain an adhesive 30. At this time, as shown in Figure 1, the pressure-sensitive adhesive sheet 20 was stacked so that its longer side crosses the polishing portion (W1). As the adhesive sheet 20, an acrylic adhesive tape (trade name: N0.31B, manufactured by Nitto Denko) was used. The pressure-sensitive adhesive 30 was left for 30 minutes under the conditions of temperature 23 ℃, humidity 50%. Then, the base material of the adhesive sheet 20 was pulled at the speed | rate of 50 m / min in 180 degree direction using the universal tension tester mentioned above, and peeled from the peeling sheet 10. FIG. And the peel force P1 in the grinding | polishing part W1 and the peeling force P2 in the non-polishing part W2 were measured, and what indicated P1 / P2 in% was made into the peeling force after-school rate of increase. After peeling, the peeling force increase rate was 100 to 150%, and it was set as O in Table 1 because there was little peeling force change with respect to friction, and it was set as x because the peeling force change was large outside the said range.

(3) curability confirmation test

The release agent layer of the release film was rubbed 10 times with a finger, and the presence or absence of generation of cloudiness (smear) of the coating was visually determined. In Table 1, 0 is smearless (curable good determination), and x is smeared (hardenability determination).

(4) adhesion confirmation test

The release layer of the release film was rubbed 10 times with a finger, and the presence or absence of film peeling (love off) was visually observed. In Table 1, "0" means no love off (adhesive good judgment), and "x" as love off (adhesive poor determination).

As is clear from the results in Table 1, in Examples 1 to 4 in which the number of alkenyl groups to the number of methyl groups in the release agent composition was in the range of 0.02 to 0.08, the peeling force was good and the release agent layer was Adhesion to the substrate was good. Moreover, even if it rubs a peeling agent layer, it can understand that there is little change in peeling force and sclerosis | hardenability of a peeling film, and high physical property stability with respect to rubbing.

On the other hand, as in Comparative Example 1, when the number of alkenyl groups with respect to the number of methyl groups is less than 0.02, adhesiveness with respect to the base material of the release agent layer is low, and physical property stability against rubbing is low, and thus a desired release film cannot be obtained. In addition, as in Comparative Example 2, when the number of alkenyl groups relative to the number of methyl groups is greater than 0.08, it can be understood that the initial peeling force becomes too heavy and the peelability deteriorates.

As mentioned above, in this invention, in the peeling agent composition containing an addition reaction type | mold silicone resin and a branched organosiloxane oligomer, by making the number of alkenyl groups into a predetermined range with respect to the number of methyl groups, peelability and a base material are The release film excellent in the adhesiveness with a peeling agent can be obtained.

Claims (3)

In an addition reaction type silicone releasing agent composition comprising a side chain comprising an addition reaction type silicone resin and an organosiloxane skeleton, or a branched organosiloxane oligomer having an alkenyl group in the side chain and the main chain, An addition reaction type silicone release agent composition, characterized in that the number of alkenyl groups included in the composition is 0.02 to 0.08 (molar ratio) relative to the number of methyl groups included in the composition. The addition reactive silicone release agent composition according to claim 1, wherein in the branched organosiloxane oligomer, the number of alkenyl groups is 0.2 to 0.5 (molar ratio) relative to the number of methyl groups. A release film, wherein a cured coating film of the addition reaction type silicone release agent composition according to claim 1 or 2 is formed on at least one side of the substrate.

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