JP4552661B2 - Manufacturing method of laminate - Google Patents

Description

  The present invention relates to a method for producing a laminate comprising a releasable resin composition. More specifically, the present invention relates to a method for producing a laminate that improves the releasability with respect to a pressure-sensitive adhesive, the like, has less release of the release agent, and has 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 the plastic as a base material instead of a coating method, a resin composition containing a small amount of polydimethylsiloxane showing a specific epoxy equivalent to an olefin polymer, And the release film which oxidized this olefin polymer surface was proposed (for example, refer patent document 1).

  According to this method, the adhesion between the olefin polymer and polydimethylsiloxane is good, but the surface exudation amount relative to the blending amount of polydimethylsiloxane is not sufficient, and the peelability is insufficient in some adhesive tape applications. In some cases, improvements were desired.

Japanese Patent Application No. 2003-392820

  The present invention has been made in view of the above-described circumstances, and maintains the adhesiveness to the base material and the adhesiveness between the olefin polymer and polydimethylsiloxane while maintaining the releasability from the pressure-sensitive adhesive. The purpose is to improve.

  As a result of intensive studies to solve the above problems, the present inventor performed extrusion lamination processing on a resin composition in which a specific polydimethylsiloxane is blended with an olefin polymer at a specific extrusion temperature and a specific air gap passage time. It has been found that the laminate improves the releasability with respect to the pressure-sensitive adhesive and the like while maintaining the adhesiveness to the substrate and the adhesion between the olefin polymer and polydimethylsiloxane, and has completed the present invention.

  That is, the present invention provides an extrusion laminating method in which at least one surface of the substrate has an olefin polymer of 95 to 99.99% by weight and an epoxy group having a functional group equivalent of 500 g / mol to 50000 g / mol and / or In the method of laminating a layer using a release resin composition comprising 0.01 to 5% by weight of polydimethylsiloxane having an amino group, the following requirements (A) and (B) are satisfied. The present invention relates to a method for manufacturing a laminate.

(A) Extrusion resin temperature of the releasable resin composition is 300 ° C. or higher and 360 ° C. or lower (B) The releasable resin composition represented by the following formula (1) is extruded from a die and cooled by a cooling roll. Time (air gap passage time) is 0.04 seconds to 0.50 seconds

Air gap passage time (second) = air gap length (m) / line speed (m / second) (1)

Furthermore, the present invention provides at least one or more kinds selected from the group consisting of corona discharge treatment, flame treatment and plasma treatment on the surface of the layer formed using the release resin composition of the laminate obtained by the above method. The present invention relates to a method for manufacturing a laminate, which is oxidized by a treatment method.

  The present invention is described in detail below.

  Examples of the substrate constituting the present invention include synthetic polymer film or sheet, woven fabric, non-woven fabric, paper, metal foil and the like. As a synthetic polymer film or sheet, for example, a film or sheet comprising 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, and 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, fabric, woven fabric or nonwoven fabric made of synthetic resin is preferable because the adhesive tape and label produced using the laminate of the present invention are excellent in adhesiveness and easy tearability.

  Moreover, you may use the surface of such a base material beforehand coat | covered with polyolefin resin, such as polyethylene and a polypropylene.

  The olefin polymer used in the present invention may be generally called a polyolefin resin, and such a polyolefin resin is an α- having 2 to 12 carbon atoms such as ethylene, propylene and 1-butene. An olefin homopolymer or copolymer is shown. 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. Such an olefin polymer can be selected from commercially available ones.

  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 such an olefin polymer is excellent in laminate moldability and adhesion to a substrate, a melt mass flow rate (hereinafter referred to as MFR) according to JIS K6922-1 (1997) is 0.1 to 100 g / 10. It is preferably in the range of minutes.

In addition, such an olefin polymer is preferable when the density measured in accordance with JIS K6922-1 (1997) is in the range of 880 to 970 kg / m ³ because of excellent releasability. When 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.

In addition, the olefin polymer used in the present invention is added with additives usually used for polyolefin resins such as antioxidants, lubricants, neutralizers, antiblocking agents, surfactants, slip agents, etc. It does not matter if you do it.
The polydimethylsiloxane used in 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 release property of the release film is inferior, and when the epoxy group and / or amino group equivalent exceeds 50000 g / mol, the polydimethylsiloxane and olefin system This is not preferable because the adhesion of the polymer becomes insufficient and the release layer is rub off.

  As the 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 present invention, a polydimethylsiloxane having a viscosity at 25 ° C. of 50 cSt or more is preferable because the weight loss during extrusion molding is small.

  Examples of the polydimethylsiloxane having an epoxy group equivalent of 500 g / mol to 50000 g / mol used in the present invention are commercially available from Shin-Etsu Chemical Co., Ltd. under the trade names Shin-Etsu Silicone KF-1001, KF-102, and the like.

  In addition, as for polydimethylsiloxane having an amino group equivalent of 500 g / mol or more and 50000 g / mol or less used in the present invention, for example, SF 8417 is commercially available from Toray Dow Corning Silicone Co., Ltd.

  The polydimethylsiloxane used in the present invention is blended in the release resin composition in an amount of 0.01 to 5% by weight. When the blending ratio of polydimethylsiloxane is less than 0.01% by weight, the amount of exudation of the polydimethylsiloxane to the surface of the laminate is small and the release property of the laminate is inferior. On the other hand, when it exceeds 5% by weight, the amount of the polydimethylsiloxane leached onto the surface of the laminate becomes excessive, and the re-adhesiveness of the pressure-sensitive adhesive adhered to the laminate is impaired. Also, the resin may slip in the extruder and extrusion lamination may not be performed.

Further, the releasable resin composition used in the present invention is an additive that is usually used for polyolefin resins, such as an antioxidant, a lubricant, a neutralizing agent, an anti-blocking agent, a surfactant, and a slip agent, if necessary. May be added.
The releasable resin composition used in 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 using the releasable resin composition that constitutes the present invention is not particularly limited as long as the object of the present invention is achieved. The thickness is preferably ˜5 mm, and the range of 1 μm to 100 μm is most preferable from the viewpoint of economy.

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

  Examples of the oxidation treatment method for oxidizing the surface of the layer formed using the releasable resin composition include chromic acid treatment, sulfuric acid treatment, air oxidation, ozone treatment, corona discharge treatment, flame treatment, and plasma treatment. In order to form oxides effectively, corona discharge treatment, flame treatment and plasma treatment are particularly preferred.

Corona discharge treatment is widely used as a continuous treatment technique for plastic film and sheet surfaces, and is performed by passing the laminate 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 by extrusion lamination molding. The extrusion laminate molding includes a coextrusion lamination method and a tandem lamination method.

  When subjected to extrusion laminating, the extrusion resin temperature of the releasable resin composition is in the range of 300 to 350 ° C, preferably 310 to 350 ° C, more preferably 320 to 350 ° C. When the extrusion resin temperature of the releasable resin composition is less than 300 ° C., the adhesive strength between the base material and the layer formed using the releasable resin composition is lowered in the obtained laminate. In addition, the amount of bleed of polydimethylsiloxane to the surface of the laminate is reduced, and the release property is inferior. Moreover, when the extrusion resin temperature of a mold release resin composition exceeds 360 degreeC, since a mold release resin composition deteriorates and a gel and a fish eye may be generated, it is unpreferable.

  When subjected to extrusion laminating, the time (air gap passage time) until the release resin composition represented by the following formula (1) is extruded from the die and cooled by the cooling roll is 0.04 second to 0 .50 seconds, preferably 0.06 seconds to 0.40 seconds, and more preferably 0.08 to 0.35.

Air gap passage time (second) = air gap length (m) / line speed (m / second) (1)
The air gap length refers to the distance from the tip of a die provided in the extrusion laminating machine to the point where the two cooling rolls are pressure-bonded. The line speed refers to the take-up speed of the base material when it is subjected to extrusion lamination molding.

  When the air gap passage time is less than 0.04 seconds, the amount of bleed of the polydimethylsiloxane to the laminate surface is decreased, and the release property is inferior. Further, when the air gap passage time exceeds 0.50 seconds, it is not preferable because the neck-in is large and the moldability is inferior when subjected to extrusion laminating. Moreover, the temperature of the releasable resin composition at the time of bonding with a base material may become low, and the adhesiveness of a base material and a releasable resin composition may deteriorate.

  The method for producing a laminate of the present invention is extremely useful as a method for producing 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 formed by using a cloth 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 at 23 ° C. for one 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 paper material that is the base material is destroyed.

Example 1
As an olefin-based polymer, low-density polyethylene (trade name Petrocene 213 manufactured by Tosoh Corporation, sometimes referred to as LDPE) 99% by weight, epoxy group and MFR 8 g / 10 min, density 918 kg / m ³ 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 A-1 hereinafter) is blended so as to be 1% by weight, and is melt-kneaded (kneading temperature 150 ° C.) with a single screw extruder (Placo Extruder diameter 50 mm) to release. A pellet of the resin composition was obtained.

The obtained pellets were supplied to an extruder of an extrusion laminator having a 90 mmφ screw, extruded from a T-die at a temperature of 320 ° C., and a high-quality paper subjected to corona treatment under the condition of 50 W · min / m ² as a base material (Hokuetsu) Laminate resin composition was laminated on a corona-treated surface of trade name Kinmari SW (basis weight 50 g / m ² ) manufactured by Paper Manufacturing Co., Ltd. so as to have a thickness of 15 μm. At that time, the air gap length was 0.15 m, and the line speed was 1.67 m / sec (air gap passage time 0.09 sec). Then, the surface which consists of a releasable resin composition of a laminated body in-line was corona-treated on 15 W * min / m < ² > conditions, and the laminated body was obtained.

  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
ライン速度を２．５０ｍ／秒とした以外は実施例１と同様にして積層体を得た。エアギャップ通過時間０．０６秒である。評価結果を表１に示した。

Example 2
A laminate was obtained in the same manner as in Example 1 except that the line speed was 2.50 m / sec. The air gap passage time is 0.06 seconds. The evaluation results are shown in Table 1.

Example 3
A laminate was obtained in the same manner as in Example 1 except that the line speed was 3.3 m / sec. The air gap passage time is 0.045 seconds. The evaluation results are shown in Table 1.

Example 4
A laminate was obtained in the same manner as in Example 1 except that the extrusion resin temperature in extrusion lamination molding was 310 ° C. The evaluation results are shown in Table 1.

Example 5
A laminate was obtained in the same manner as in Example 1 except that the extrusion resin temperature in the extrusion lamination molding was changed to 330 ° C. The evaluation results are shown in Table 1.

Example 6
A laminate was obtained in the same manner as in Example 1 except that the extrusion resin temperature in extrusion lamination molding was 340 ° C. The evaluation results are shown in Table 2.

実施例７
オレフィン系重合体として、ＬＤＰＥを９９重量％、エポキシ変性ポリジメチルシロキサン（Ａ−１）を１重量部とした代わりに、ＬＤＰＥを９８重量％、エポキシ変性ポリジメチルシロキサン（Ａ−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２に示した。

Example 7
As an olefin polymer, LDPE was replaced by 99% by weight and epoxy-modified polydimethylsiloxane (A-1) by 1 part by weight. Instead of LDPE by 98% by weight and epoxy-modified polydimethylsiloxane (A-1) by 2%. % To obtain a laminate in the same manner as in Example 1. The evaluation results are shown in Table 2.

Example 8
As an olefin polymer, instead of LDPE 99 wt% and epoxy-modified polydimethylsiloxane (A-1) 1 wt%, LDPE 99 wt%, epoxy group and / or amino group equivalent is 500 g / mol or more. Polydimethylsiloxane having an amino group equivalent of 1800 g / mol and a viscosity of 1200 cSt as a polydimethylsiloxane having a molecular weight of 50000 g / mol or less (trade name SF8417 manufactured by Toray Dow Corning Silicone Co., Ltd., hereinafter referred to as A-2) In some cases, 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 2.

Example 9
As an olefin polymer, 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 (trade name Affinity PT1450 manufactured by Dow Chemical Co., Ltd. may be referred to as C8LL hereinafter). A laminated body was obtained in the same manner as in Example 1 except that. The evaluation results are shown in Table 2.

Example 10
As the olefin polymer, instead of LDPE, sometimes MFR referred is 6.5 g / 10 min, density of 940 kg / ^{m 3} and a medium density polyethylene (Tosoh Co., trade name Petrocene LW04-1, less MDPE Except for the above, a laminate was obtained in the same manner as in Example 1. The evaluation results are shown in Table 2.

Comparative Example 1
A laminate was obtained in the same manner as in Example 1 except that the extrusion resin temperature in extrusion lamination molding was 280 ° C. The evaluation results are shown in Table 3, but the releasability was poor.

比較例２
押出ラミネート成形における押出樹脂温度を３７０℃とした以外は実施例１と同様にして積層体の製造を試みたが、離型性樹脂組成物の熱劣化が激しく、積層体を得ることができなかった。

Comparative Example 2
Except for setting the extrusion resin temperature in extrusion lamination molding to 370 ° C., an attempt was made to produce a laminate in the same manner as in Example 1, but the heat release of the releasable resin composition was so severe that a laminate could not be obtained. It was.

Comparative Example 3
A laminate was obtained in the same manner as in Example 1 except that the air gap length was 0.10 m and the line speed was 3.33 m / sec (air gap passage time 0.03 sec). The evaluation results are shown in Table 3, but the releasability was poor.

Comparative Example 4
An attempt was made to produce a laminate in the same manner as in Example 1 except that the air gap length was 0.15 m and the line speed was 0.25 m / sec (air gap passage time 0.6 sec). The moldability was large and the laminate could not be obtained.

Claims (4)

Polydimethyl having 95 to 99.99% by weight of an olefin polymer and an epoxy group and / or an amino group having a functional group equivalent of 500 g / mol to 50000 g / mol on at least one surface of the substrate by an extrusion lamination method. In a method of laminating a layer formed using a release resin composition composed of 0.01 to 5% by weight of siloxane, the laminate satisfies the following requirements (A) and (B): Production method.
(A) Extrusion resin temperature of the releasable resin composition is 300 ° C. or higher and 350 ° C. or lower (B) The releasable resin composition represented by the following formula (1) is extruded from a die and cooled by a cooling roll. Time (air gap passage time) is 0.04 seconds to 0.09 seconds

Air gap passage time (second) = air gap length (m) / line speed (m / second) (1) The surface of the layer formed using the releasable resin composition is oxidized by at least one treatment method selected from the group consisting of corona discharge treatment, flame treatment, and plasma treatment. The manufacturing method of the laminated body. The method for producing a laminate according to claim 1 or 2, wherein the substrate is one or more selected from paper, cloth, woven fabric or nonwoven fabric made of synthetic resin. (A) Extrusion resin temperature of the releasable resin composition is 310 ° C. or higher and 350 ° C. or lower
The manufacturing method of the laminated body in any one of Claims 1-3 characterized by the above-mentioned.