JP2006192865A - Laminate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate which, while maintaining releasability with an adhesive and adhesion between an olefinic polymer and a polydimethylsiloxane, has improved adhesiveness with a base material. <P>SOLUTION: The laminate is formed by laminating on at least one surface of a base material a layer (A) that satisfies the following requirement and, on the layer (A), a layer (B) that satisfies the following requirement. Herein, the layer (A) is a layer consisting of an olefinic polymer, and the layer (B) is a layer consisting of a releasable resin composition consisting of 95-99.99 wt% of an olefinic polymer and 0.01-5 wt% of a polydimethylsiloxane having an epoxy group and/or an amino group having a functional group equivalent of ≥500 g/mol and ≤50,000 g/mol. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a laminate comprising a release film resin composition. More specifically, the present invention relates to a laminate having excellent releasability with respect to a pressure-sensitive adhesive and the like, improved release of the release agent, and excellent adhesion to a substrate.

  The release film is a film-like material provided with a release surface that is laminated on the adhesive surface to protect the adhesive surface of the adhesive material when not in use, and is easily peeled without damaging the adhesive surface when in use. Widely used as a mount for adhesive tapes and labels. The release film usually includes a base material and a release layer containing a release agent provided on at least one surface of the base material. Paper, plastic film, etc. are used for the base material, and a silicone compound, a long-chain alkyl group-containing compound, etc. are used for the release agent. In such a release film, when the release agent is not sufficiently adhered to the substrate, the release agent is transferred to the adhesive surface of the tape or label when the tape or label is peeled off from the release film. And the stickiness of the label may be deteriorated.

  For this reason, as a method for producing a release film, a method in which a release agent such as vinyl group-containing polydimethylsiloxane is coated on a substrate and then the release agent is cured is generally used. However, in this method, there are problems that a large amount of an organic solvent is used to uniformly apply the release agent, and that the base material is exposed to a high temperature when the release agent is cured, so that pinholes are generated. It was happening.

  For this reason, the present inventor, as a method for imparting releasability to a plastic as a base material instead of a coating method, includes a resin composition containing a small amount of polydimethylsiloxane having a specific epoxy equivalent in an olefin polymer, and A release film was proposed in which the olefin polymer surface was oxidized (see, for example, Patent Document 1).

  According to this method, although the adhesion between the olefin polymer and polydimethylsiloxane is good, the adhesive strength between the substrate and the resin composition is insufficient in some adhesive tape applications that require heavy peelability. There was a case. In this case, there is a problem that peeling does not occur between the pressure-sensitive adhesive and the resin composition but peeling between the base material and the resin composition, and improvement has been desired.

Japanese Patent Application No. 2003-392820

  The present invention has been made in view of the situation as described above, and maintains adhesiveness with a base material while maintaining releasability with an adhesive and adhesion between an olefin polymer and polydimethylsiloxane. The purpose is to improve.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have provided a layer made of an olefin polymer on at least one side of the substrate, and further comprises an olefin polymer and a specific polydimethylsiloxane on the layer. It has been found that the laminate in which the layer is formed is excellent in releasability with the pressure-sensitive adhesive and exhibits high adhesive strength with the base material, and has completed the present invention.

That is, the present invention is a laminate characterized in that (A) layer satisfying the following requirements is laminated on at least one surface of the substrate, and (B) layer satisfying the following requirements is laminated on the (A) layer in this order. It is about the body.
(A) Layer: A layer made of an olefin polymer.
(B) Layer: 95 to 99.99% by weight of olefin polymer and 0.01 to 5% by weight of polydimethylsiloxane having an epoxy group and / or an amino group having a functional group equivalent of 500 g / mol to 50000 g / mol. A layer comprising a releasable resin composition comprising:

  The present invention is described in detail below.

  As for the base material which comprises the laminated body of this invention, a synthetic polymer film or sheet, a woven fabric, a nonwoven fabric, paper, metal foil, etc. are mentioned. As a synthetic polymer film or sheet, for example, a film or sheet made of a synthetic polymer such as polyester such as polyethylene terephthalate, polyamide, polyvinyl alcohol, saponified ethylene / vinyl acetate copolymer, polycarbonate, polyethylene, polypropylene, etc. Is mentioned. Further, these high polymer films or sheets may be further subjected to aluminum vapor deposition or alumina vapor deposition. Further, these polymer films or sheets may be further printed using urethane ink or the like. Examples of the woven fabric and non-woven fabric include those made of synthetic resin such as polyester, polyethylene, and polypropylene, or those made of natural materials such as sufu. Examples of the paper include craft paper, kulpack paper, high-quality paper, glassine paper, and paperboard.

  In particular, one or more selected from paper, cloth, woven cloth or non-woven cloth made of a synthetic resin is preferable because the pressure-sensitive adhesive tape and label produced using the laminate of the present invention are excellent in tackiness and easy tearability.

  The olefin polymer used in the layer (A) of the present invention may be generally called a polyolefin resin, and such a polyolefin resin has 2 carbon atoms such as ethylene, propylene and 1-butene. A homopolymer or copolymer of? For example, high pressure method low density polyethylene, high density polyethylene, medium density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene / 4-methyl- 1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid ester copolymer, etc. Examples thereof include ethylene polymers, polypropylene, propylene / ethylene copolymers, propylene / 1-butene copolymers, poly-1-butene, poly-1-hexene, poly-4-methyl-1-pentene, and the like. The combination may be used alone or in combination of two or more.

  Among these, high pressure method low density polyethylene, high density polyethylene, medium density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene / 4 A methyl-1-pentene copolymer and an ethylene / vinyl acetate copolymer are preferable because they are excellent in cost performance and adhesion to a substrate.

  Since the olefin polymer used for the layer (A) of the present invention is excellent in laminate moldability and adhesion to a substrate, the melt mass flow rate (hereinafter referred to as MFR) according to JIS K6922-1 (1997) is 0. It is preferable that it exists in the range of 1-100 g / 10min.

Moreover, since the olefin polymer used for the (A) layer of the present invention has a density measured in accordance with JIS K6922-1 (1997) in the range of 880 to 970 kg / m ³ , it is preferable. If the density is too low, the heat resistance of the release film is insufficient in the pressure-sensitive adhesive application step, and the adhesive strength between the pressure-sensitive adhesive and the release film may increase. On the other hand, if the density is too high, the rigidity of the film may become too high.

Further, the olefin polymer used in the layer (A) of the present invention is usually used for polyolefin resins such as antioxidants, lubricants, neutralizers, antiblocking agents, surfactants, slip agents, and the like as necessary. It is also possible to add an additive.
The thickness of the layer (A) constituting the present invention is not particularly limited as long as the object of the present invention is achieved, and is excellent in flexibility and has few problems such as breakage, so that the thickness is 1 μm to 5 mm. From the viewpoint of economy, the range of 1 μm to 100 μm is most preferable.

  The olefin polymer used for the layer (B) of the present invention may be generally referred to as a polyolefin resin, and such a polyolefin resin may have 2 to 2 carbon atoms such as ethylene, propylene and 1-butene. 12 shows a homopolymer or copolymer of 12 α-olefins. For example, high pressure method low density polyethylene, high density polyethylene, medium density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene / 4-methyl- 1-pentene copolymer, ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ethylene / acrylic acid ester copolymer, ethylene / methacrylic acid ester copolymer, etc. Examples thereof include ethylene polymers, polypropylene, propylene / ethylene copolymers, propylene / 1-butene copolymers, poly-1-butene, poly-1-hexene, poly-4-methyl-1-pentene, and the like. The combination may be used alone or in combination of two or more.

  Among these, high pressure method low density polyethylene, high density polyethylene, medium density polyethylene, ethylene / 1-butene copolymer, ethylene / 1-hexene copolymer, ethylene / 1-octene copolymer, ethylene / 4 A methyl-1-pentene copolymer and an ethylene / vinyl acetate copolymer are preferable because they are excellent in cost performance and adhesion to a substrate.

  Since the olefin polymer used for the layer (B) of the present invention is excellent in laminate moldability, the melt mass flow rate (hereinafter referred to as MFR) according to JIS K6922-1 (1997) is 0.1 to 100 g / 10 min. It is preferable that it exists in the range.

Moreover, since the olefin polymer used for the (B) layer of this invention has the density measured by JISK6922-1 (1997) in the range of 880-970 kg / m < ³ >, since it is excellent in mold release property, it is preferable. If the density is too low, the heat resistance of the release film is insufficient in the pressure-sensitive adhesive application step, and the adhesive strength between the pressure-sensitive adhesive and the release film may increase. On the other hand, if the density is too high, the rigidity of the film may become too high.

  The polydimethylsiloxane used in the layer (B) of the present invention has an epoxy group and / or amino group equivalent of 500 g / mol or more and 50000 g / mol or less. When the epoxy group and / or amino group equivalent is less than 500 g / mol, the releasability of the release film is inferior, which is not preferable. When the epoxy group and / or amino group equivalent exceeds 50000 g / mol, polydimethylsiloxane and (B ), The adhesion of the olefinic polymer used in the layer is insufficient, and the release layer is unfavorably rub off.

  Polydimethylsiloxane having an epoxy group and / or amino group equivalent of 500 g / mol or more and 50000 g / mol or less used in the layer (B) of the present invention has a viscosity at 25 ° C. of 50 cSt or more. Is preferable.

  The polydimethylsiloxane having an epoxy group equivalent of 500 g / mol or more and 50000 g / mol or less used in the layer (B) of the present invention includes, for example, Shin-Etsu Silicone KF-1001, KF-102, etc. from Shin-Etsu Chemical Co., Ltd. It is commercially available.

  In addition, polydimethylsiloxane having an amino group equivalent of 500 g / mol or more and 50000 g / mol or less used for the layer (B) of the present invention is commercially available, for example, SF8417 from Toray Dow Corning Silicone Co., Ltd.

Furthermore, the releasable resin composition used for the layer (B) of the present invention is usually converted into a polyolefin-based resin such as an antioxidant, a lubricant, a neutralizing agent, an anti-blocking agent, a surfactant, and a slip agent as necessary. What added the additive used may be used.
The releasable resin composition used for the layer (B) of the present invention can be produced by a commonly used resin mixing apparatus. For example, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a pressure kneader, a melt kneader such as a rotating roll, a Henschel mixer, a V blender, a ribbon blender, a tumbler, and the like can be given. When using a melt-kneading apparatus, the melting temperature is preferably about the melting point of the olefin polymer to about 350 ° C.

  The thickness of the layer (B) constituting the present invention is not particularly limited as long as the object of the present invention is achieved, and is excellent in flexibility and has few problems such as breakage, so that the thickness is 1 μm to 5 mm. From the viewpoint of economy, a range of 1 μm to 100 μm is more preferable.

  The (B) layer surface of the laminate of the present invention is preferably oxidized in order to suppress the transfer of the release agent to the adhesive surface of the tape or label. Further, the peeling strength is reduced by the oxidation, and the releasability can be improved.

  (B) Examples of the oxidation treatment method for oxidizing the layer surface include chromic acid treatment, sulfuric acid treatment, air oxidation, ozone treatment, corona discharge treatment, flame treatment, plasma treatment and the like. Corona discharge treatment, flame treatment, and plasma treatment are preferable in order to effectively form an object.

Corona discharge treatment is widely used as a continuous treatment technique for plastic film and sheet surfaces, and is performed by passing the film through a corona atmosphere generated by a corona discharge treatment machine. The corona discharge density is preferably 1 to 100 W · min / m ² because of excellent re-tackiness of the pressure-sensitive adhesive.

  The flame treatment is performed by bringing the film surface into contact with a flame generated when natural gas, propane, or the like is burned.

  Plasma treatment is an excited inert gas that is electrically neutral after removing charged particles by electronically exciting a single or mixed gas such as argon, helium, neon, hydrogen, oxygen, and air with a plasma jet. Is sprayed onto the film surface.

  The laminate of the present invention can be produced using a calendar molding machine, a press molding machine, an extrusion laminating machine or the like. In extrusion lamination molding, a coextrusion lamination method and a tandem lamination method are preferable from the viewpoint of economy.

  When subjected to extrusion laminating, the extrusion resin temperature of the olefin polymer used for the layer (A) and the releasable resin composition used for the layer (B) is preferably in the range of 200 to 350 ° C., more preferably It is the range of 240-340 degreeC. When the extrusion resin temperature of the olefin-based polymer used for the (A) layer and the releasable resin composition used for the (B) layer is less than 200 ° C., in the obtained laminate, the base material / (A) interlayer and The adhesive strength between the (A) layer / (B) layer may be lowered. On the other hand, when the extrusion resin temperature of the olefin polymer used for the (A) layer and the releasable resin composition used for the (B) layer exceeds 350 ° C., the resin deteriorates, and the desired performance cannot be obtained. Sometimes.

  The laminate of the present invention is extremely useful as a wide range of industrial materials such as labels, sealing release papers and tapes.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these Examples.

  The measurement methods and evaluation methods for physical properties and workability are shown below.

(1) Melt mass flow rate (MFR)
It measured based on JISK6922-1 (1997).

(2) Density The density was measured in accordance with JIS K6922-1 (1997).

(3) Release property A 50 mm wide and 150 mm long cloth adhesive tape (trade name cloth adhesive tape No. 3310, manufactured by Sliontec Co., Ltd.) was applied to the surface of the release film side of the laminate obtained in the examples, and the linear pressure After passing between the rubber rolls under conditions of 5 kg / cm and a speed of 5 m / min, it was left in an atmosphere at 40 ° C. for 7 days to obtain a sample for measuring releasability. Thereafter, the sample was cut to a width of 15 mm, and the adhesive strength between the cloth adhesive tape and the release film was measured with a tensile tester (Autograph DCS-100, manufactured by Shimadzu Corporation). The peeling speed is 300 mm / min.

(4) Re-adhesiveness of pressure-sensitive adhesive tape An aluminum plate (trade name A1N30H-H18, manufactured by Toyo Aluminum Co., Ltd., thickness 0.1 mm) was used to remove the cloth pressure-sensitive adhesive tape having a width of 15 mm peeled from the surface of the release film by the above-described releasability test. The film was affixed at a linear pressure of 5 kg / cm. After leaving in an atmosphere of 23 ° C. for 1 day, the adhesive strength between the cloth adhesive tape and the aluminum plate was measured with a tensile tester (Autograph DCS-100, manufactured by Shimadzu Corporation). The peeling speed is 300 mm / min. When the pressure-sensitive adhesive surface of the pressure-sensitive adhesive tape is contaminated by the release film, the re-adhesiveness of the pressure-sensitive adhesive tape is lowered and the performance as the pressure-sensitive adhesive tape is impaired. That is, it is preferable that the re-adhesion strength is higher.

(5) Adhesiveness with base material The adhesive strength between the paper / (A) layers of the laminates obtained in the examples was measured with a tensile tester (manufactured by Shimadzu Corporation, Autograph DCS-100). The peeling speed is 300 mm / min, and the width of the test piece is 15 mm. It can be said that the adhesiveness to the base material is good if it is adhered to such an extent that the material of the paper as the base material is destroyed.

Example 1
As an olefin polymer, low-density polyethylene (trade name Petrocene 205 manufactured by Tosoh Corporation, which may be referred to as LDPE hereinafter) having an MFR of 3 g / 10 min and a density of 924 kg / m ³ is 99% by weight, epoxy group and As the polydimethylsiloxane having an amino group equivalent of 500 g / mol or more and 50000 g / mol or less, an epoxy-modified polydimethylsiloxane having an epoxy equivalent of 3500 g / mol and a viscosity of 17000 cSt (trade name Shin-Etsu Silicone KF- manufactured by Shin-Etsu Chemical Co., Ltd.) 1001, which may be referred to as B-1 hereinafter) is blended to 1% by weight, melt-kneaded (kneading temperature 150 ° C.) with a single screw extruder (Placo caliber 50 mm), (B) layer A pellet of the releasable resin composition used for the above was obtained.

On the corona-treated surface of high-quality paper (product name Kinmari SW, basis weight 50 g / m ² manufactured by Hokuetsu Paper Co., Ltd.) subjected to corona treatment under the condition of 50 W · min / m ² as a base material, LDPE ( Tosoh Co., Ltd. product name Petrocene 205) pellets were supplied to an extruder of an extrusion laminator having a 25 mmφ screw, extruded from a T-die at a temperature of 310 ° C., and laminated to a thickness of 15 μm.

Further, on the surface of the layer (A), as the layer (B), the releasable resin composition obtained by the above method is supplied to an extruder of an extrusion laminator having a screw of 25 mmφ, and from a T die at a temperature of 310 ° C. After extruding and laminating to a thickness of 15 μm, the surface of layer (B) was subjected to corona treatment under the condition of 15 W · min / m ² to obtain a laminate.

  After the obtained laminate was stored in an oven kept at 40 ° C. for 20 hours, the releasability, re-tackiness, and adhesion to the substrate were measured, and the measurement results are shown in Table 1.

実施例２
（Ｂ）層として、ＬＤＰＥを９９重量％、エポキシ変性ポリジメチルシロキサン（Ｂ−１）を１重量％の代わりに、ＬＤＰＥを９８重量％、エポキシ変性ポリジメチルシロキサン（Ｂ−１）を２重量％とした以外は、実施例１と同様にして積層体を得た。評価結果は表１に示した。

Example 2
(B) As a layer, instead of 99% by weight of LDPE and 1% by weight of epoxy-modified polydimethylsiloxane (B-1), 98% by weight of LDPE and 2% by weight of epoxy-modified polydimethylsiloxane (B-1) A laminate was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 1.

Example 3
As the layer (B), instead of 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1), 99% by weight of LDPE and an epoxy group and / or amino group equivalent of 500 g / mol or more and 50,000 g As a polydimethylsiloxane having an amino group equivalent of 1800 g / mol and a viscosity of 1200 cSt, amino-modified silicone (B-2) manufactured by Toray Dow Corning Silicone Co., Ltd., trade name SF8417, hereinafter referred to as B-2 A laminate was obtained in the same manner as in Example 1 except that the content was 1% by weight. The evaluation results are shown in Table 1.

Example 4
As the layer (B), instead of 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1), ethylene 1 having an MFR of 7.5 g / 10 min and a density of 902 kg / m ³ -Octene copolymer (trade name Affinity PT1450 manufactured by Dow Chemical Co., Ltd., hereinafter sometimes referred to as C8LL) was 99 wt%, and the epoxy-modified polydimethylsiloxane (B-1) was 1 wt%. A laminate was obtained in the same manner. The evaluation results are shown in Table 1.

Example 5
As the layer (A), instead of LDPE, an ethylene / 1-octene copolymer having a MFR of 7.5 g / 10 min and a density of 902 kg / m ³ (product name affinity PT1450 manufactured by Dow Chemical, hereinafter referred to as C8LL) A laminated body was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 1.

Example 6
As the layer (B), instead of 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1), medium density polyethylene having an MFR of 6.5 g / 10 min and a density of 940 kg / m ³ (Tosoh Corporation product name Petrocene LW04-1, hereinafter may be referred to as MDPE) was 99% by weight and epoxy-modified polydimethylsiloxane (B-1) was 1% by weight. Thus, a laminate was obtained. The evaluation results are shown in Table 1.

Example 7
As the layer (A), instead of LDPE, medium density polyethylene (trade name Petrocene LW04-1, manufactured by Tosoh Corporation) having an MFR of 6.5 g / 10 min and a density of 940 kg / m ³ may be referred to as MDPE. A laminated body was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 1.

Comparative Example 1
As a layer (A), a laminate was obtained in the same manner as in Example 1 except that instead of LDPE, LDPE was 99 wt% and epoxy-modified polydimethylsiloxane (B-1) was 1 wt%. The evaluation results are shown in Table 2, but the adhesion between the fine paper and the (B) layer was inferior.

比較例２
（Ｂ）層として、ＬＤＰＥを９９重量％、エポキシ変性ポリジメチルシロキサン（Ｂ−１）を１重量％の代わりに、ＬＤＰＥを１００重量％とした以外は、実施例１と同様にして積層体を得た。評価結果は表２に示したが、離型性が劣っていた。

Comparative Example 2
As the layer (B), the laminate was prepared in the same manner as in Example 1, except that 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1) were changed to 100% by weight of LDPE. Obtained. The evaluation results are shown in Table 2, but the releasability was poor.

Comparative Example 3
(B) As a layer, instead of 99% by weight of LDPE and 1% by weight of epoxy-modified polydimethylsiloxane (B-1), 94% by weight of LDPE and 6% by weight of epoxy-modified polydimethylsiloxane (B-1) A laminate was produced in the same manner as in Example 1, except that the laminate could not be obtained due to poor extrusion.

Comparative Example 4
As the layer (B), instead of 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1), 99% by weight of LDPE, an epoxy group equivalent of 350 g / mol, and an epoxy-modified poly having a viscosity of 1500 cSt Except for using 1% by weight of dimethylsiloxane (B-3) (trade name Shin-Etsu Silicone KF-101 manufactured by Shin-Etsu Chemical Co., Ltd., hereinafter sometimes referred to as B-3), the same procedure as in Example 1 was performed. A laminate was obtained. Although the evaluation result was shown in Table 2, it was inferior to mold release property.

Comparative Example 5
As the layer (B), instead of 99% by weight of LDPE and 1% by weight of the epoxy-modified polydimethylsiloxane (B-1), 99% by weight of LDPE and polydimethylsiloxane having a viscosity of 10,000 cSt having no organic substituent (B-4) The same as Example 1 except that the product name SH-200 manufactured by Toray Dow Corning Silicone Co., Ltd. (hereinafter sometimes referred to as B-4) was 1% by weight. A laminate was obtained. Although the evaluation result was shown in Table 2, the adhesiveness of the adhesive was inferior.

Claims (4)

A laminate comprising: (A) a layer satisfying the following requirements on at least one surface of a substrate; and (B) a layer satisfying the following requirements on the (A) layer.
(A) Layer: A layer made of an olefin polymer.
(B) Layer: 95 to 99.99% by weight of olefin polymer and 0.01 to 5% by weight of polydimethylsiloxane having an epoxy group and / or an amino group having a functional group equivalent of 500 g / mol to 50000 g / mol. A layer comprising a releasable resin composition comprising: The layered product according to claim 1, wherein the surface of the layer (B) is oxidized. The laminate according to claim 2, wherein the oxidation treatment is at least one treatment method selected from the group consisting of corona discharge treatment, flame treatment, and plasma treatment. The laminate according to any one of claims 1 to 3, wherein the substrate is at least one selected from paper, cloth, woven fabric or nonwoven fabric made of synthetic resin.