JP2018053077A - Hot-melt adhesive composition, hot-melt adhesive sheet and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hot-melt adhesive composition which has improved performances at high temperature such as material physical properties and reliability of adhesiveness at high temperature in the vicinity (90°C or higher) of a glass transition temperature (Tg) of polystyrene while utilizing merits such as good physical properties, and its supply properties and inexpensive price of a styrenic elastomer.SOLUTION: A hot-melt adhesive composition contains (B) a polyether-based resin of 0.5-20 pts. mass, (C) a hydrocarbon-based tackifier of 0.5-20 pts.mass and (D) a rosin-based tackifier of 0.5-20 pts.mass, with respect to (A) a styrenic elastomer of 100 pts.mass.SELECTED DRAWING: None

Description

  The present invention relates to a hot melt adhesive composition that is excellent in adhesive strength at high temperatures and excellent in adhesiveness even after being exposed to hot water among thermoplastic elastomer resin compositions, and the adhesive composition in sheet form. The present invention relates to a hot melt adhesive sheet molded into a laminate and a laminate obtained using the hot melt adhesive composition.

  In recent years, hot melt adhesives have been used frequently because they have characteristics such as being able to reduce the time required for adhesion and being low volatile organic compounds (low VOC).

  As the base polymer of the hot melt adhesive, rubber, thermoplastic elastomer, urethane resin, polyamide resin, and the like are used. In particular, the thermoplastic elastomer is often used recently because it has physical properties close to rubber and can be recycled. . There are various types of thermoplastic elastomers, but styrene-based elastomers are generally used as a relatively inexpensive material with a large production amount.

  As a hot melt adhesive composition using a styrene-based elastomer, for example, a material in which a tackifier, a plasticizer, an antioxidant, and the like are blended in addition to the styrene-based elastomer is known (for example, Patent Document 1). reference).

  In recent years, hot-melt adhesive compositions with high heat resistance have been used for interior and exterior materials for automobiles and the like (see, for example, Patent Documents 2 and 3).

JP 2011-190287 A JP 2007-280719 A JP 2006-236671 A

  However, the styrenic elastomer maintains material properties due to pseudo-crosslinking of polystyrene domains, and has difficulty in physical properties at high temperatures near the glass transition temperature of polystyrene (90 ° C. or more).

  Further, in Patent Document 2, although creep resistance is improved, physical properties at high temperatures near the glass transition temperature of polystyrene (90 ° C. or higher) are difficult. Further, in Patent Document 3, although improvement in hot water resistance and acid resistance is seen, the adhesion reliability at high temperature is insufficient.

  Therefore, the present invention has been made to solve the above-mentioned problems, taking advantage of the good physical properties of the styrene-based elastomer and the merit that its supply property is good and inexpensive, and the above-mentioned performance at high temperatures. It aims at providing the hot-melt-adhesive agent composition which improved this.

  As a result of extensive research, the present inventors have found that the above-mentioned problems can be solved by using a combination of a polyether resin and a predetermined tackifier in a styrene elastomer, and the present invention has been completed. It is a thing.

  That is, the hot melt adhesive composition of the present invention comprises (A) 100 parts by mass of a styrene elastomer, (B) 0.5 to 20 parts by mass of a polyether resin, and (C) a hydrocarbon tackifier 0. 5 to 20 parts by mass and (D) 0.5 to 20 parts by mass of a rosin-based tackifier.

  The hot melt adhesive sheet of the present invention is a sheet-like molded product using the hot melt adhesive composition of the present invention.

  The laminate of the present invention is characterized in that the substrate and the object to be bonded are bonded via the hot melt adhesive composition of the present invention.

  According to the hot melt adhesive composition and the hot melt adhesive sheet of the present invention, various materials can be bonded by a simple operation of cooling after heating, and at a high temperature of 90 ° C. or higher. Good adhesion that can be stably adhered even when exposed to water.

  Since the laminate of the present invention uses such a hot melt adhesive composition, it can be produced by a simple operation, and has superior adhesiveness at high temperatures as compared with a conventionally known hot melt adhesive composition. It is excellent in product stability.

Hereinafter, the present invention will be described in detail.
The present invention comprises (A) a styrene-based elastomer, (B) a polyether-based resin, (C) a hydrocarbon-based tackifier, and (D) a rosin-based tackifier, as essential components. It is a hot-melt-adhesive composition containing with the compounding quantity. Hereinafter, each component will be described.

  (A) Styrenic elastomer is the main component of the hot melt adhesive composition, and is intended to maintain a highly elastic rubber state at room temperature. it can.

  This (A) styrene-based elastomer has a pseudo-crosslinked structure formed by aggregation of polystyrene domains, and is excellent in physical properties such as strength until the polystyrene phase reaches the glass transition temperature. Moreover, since it is comparatively cheap as an elastomer, the manufacturing cost of an adhesive material can be suppressed effectively.

  (A) Examples of the styrene elastomer include polystyrene-polybutadiene-polystyrene (SBS), polystyrene-poly (butadiene-butylene) -polystyrene (SBBS), polystyrene-poly (ethylene-butylene) -polystyrene (SEBS), polystyrene- Preferred examples include poly (ethylene-propylene) -polystyrene (SEPS), polystyrene-poly (ethylene-ethylene / propylene) -polystyrene (SEEPS), and the like.

  Among them, polystyrene-poly (ethylene-ethylene / propylene) -polystyrene (SEEPS) is suitable as an adhesive material because of its excellent interfacial adhesion to non-polar objects, flexibility at low temperatures, and water absorption resistance. Can be used.

  (B) The polyether resin is a polymer compound having a repetition in which an aromatic ring, an alkyl group, a sulfone group, etc. are bonded by an ether bond, and improves the heat resistance of the styrene elastomer and is good even at high temperatures. Used for the purpose of maintaining adhesiveness.

  As this (B) polyether-based resin, for example, polyether ether ketone, polyether ketone, polyether sulfone, and polyphenylene ether can be used. (A) From the viewpoint of compatibility with styrene-based elastomer, polyphenylene ether Is preferred.

  (B) It is preferable that content of polyether-type resin is 1-20 mass parts with respect to 100 mass parts of styrene-type elastomers. When this content is less than 1 part by mass, it becomes difficult to obtain adhesive strength at high temperatures (100 to 110 ° C.), and the adhesiveness is lowered. On the other hand, when the content exceeds 20 parts by mass, the flexibility of the styrene-based elastomer is impaired, and the action of relaxing the stress is reduced.

  Moreover, the hot-melt-adhesive composition of this invention contains the following 2 types of tackifier, (C) hydrocarbon type tackifier, and (D) rosin type tackifier as an essential component. By blending both of these tackifiers, it is possible to obtain good adhesion to various adherends from generally difficult-to-adhere polyolefin to metal.

  Here, (C) the hydrocarbon tackifier is a resin obtained by polymerizing a hydrocarbon component having 5 or 9 carbon atoms in the petroleum fraction, for example, a C5, C9 hydrocarbon resin, C5 , C9 hydrogenated hydrocarbon resins and coumarone indene resins.

  The (D) rosin-based tackifier is a resin derived from rosin, which is a natural resin, and examples thereof include polymerized rosin and rosin ester.

  Among these, it is preferable that (C) is a C5 hydrocarbon resin and (D) is a rosin ester. From the viewpoint of hot water resistance, (C) is more preferably a C5 aliphatic hydrocarbon resin, and (D) is more preferably a rosin ester.

  (C) The content of the hydrocarbon tackifier needs to be 0.5 to 20 parts by mass, and more preferably 5 to 15 parts by mass with respect to 100 parts by mass of the styrene elastomer. When the content is less than 0.5 parts by mass, the adhesion with a low-polar surface is lowered, and the adhesion at normal temperature is also lowered. On the other hand, when this content exceeds 20 mass parts, it is inferior to heat resistance and the adhesiveness at the time of high temperature falls.

  (D) Content of rosin system tackifier needs to be 0.5-20 mass parts with respect to 100 mass parts of styrene-type elastomers, and it is more preferable that it is 5-15 mass parts. If the amount is less than 0.5 parts by mass, the adhesion to the polar surface mainly decreases, and the adhesion at normal temperature also decreases. On the other hand, when this content exceeds 20 mass parts, it is inferior to heat resistance and the adhesiveness at the time of high temperature falls.

  The hot melt adhesive composition of the present invention contains the above components (A) to (D) as essential components, but may further contain (E) a filler.

  (E) The filler contributes to an increase in resin strength and a decrease in linear expansion coefficient in the cured product of the hot melt adhesive composition, and is used for the purpose of improving the adhesion reliability at high temperatures. As this (E) filler, conventionally known fillers added to a resin composition such as inorganic particles, inorganic fibers, organic particles, and organic fibers can be used.

  Examples of inorganic particles include particles such as talc, calcium carbonate, silica, clay, silicon carbide, and graphite. Examples of the inorganic fibers include glass chopped strands and carbon fibers. Examples of the organic particles include phenol resin particles. Examples of organic fibers include fibers such as polyester, polyamide, and cellulose.

  (E) 1-50 mass parts is preferable with respect to 100 mass parts of (A) styrene-type elastomer, and, as for content of a filler, it is more preferable that it is 10-35 mass parts. When this content is less than 1 part by mass, the adhesiveness at high temperatures may be reduced. On the other hand, when the content exceeds 50 parts by mass, the flexibility of the elastomer and the wettability at the time of heat bonding are impaired, and the adhesiveness may be lowered.

  Further, the hot melt adhesive composition of the present invention may be blended with other thermosetting resins for the purpose of pre-curing by heating or improving the crosslinking density. Examples of the thermosetting resin used here include bisphenol type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, triphenylmethane type epoxy resins, and fluorene type epoxy resins. A thermosetting resin may be used independently and may be used in mixture of 2 or more types.

  In addition, the hot melt adhesive of the present invention may be blended with a photocurable resin for the purpose of precuring by ultraviolet irradiation or improving the crosslinking density. Examples of the photocurable resin used here include acrylic resins and oxetane resins. A photocurable resin may be used independently and may be used in mixture of 2 or more types.

  Furthermore, the hot melt adhesive of the present invention may contain an antioxidant, an antifoaming agent, a leveling agent, a colorant and the like in addition to the above components as long as the effects of the present invention are not impaired.

  The hot melt adhesive of the present invention is made into a varnish state by dissolving and dispersing other optional components in an organic solvent in addition to the above-described components (A) to (D), which are essential components, and the varnish is subjected to various methods. By molding with, a desired shape of the adhesive can be obtained. More specifically, the (A) styrenic elastomer is added to an organic solvent in which the various raw materials are commonly dissolved, for example, toluene, and the mixture is stirred and dissolved at a temperature of 25 ° C to 50 ° C. Furthermore, (B) polyether resin, (C) hydrocarbon tackifier, (D) rosin tackifier, (E) filler, and other optional components are added, and a temperature of 20 to 50 ° C. To disperse and dissolve. There is no restriction | limiting in the order which adds and mixes, You may stir and mix the solution which melt | dissolved the component (A)-(E) and another arbitrary component, respectively.

  When the above components (A) to (E) and other optional components are mixed, they may be dispersed and dissolved using a stirring blade, a bead mill, a three roll mill, a jet mill, a kneader, or the like. At the time of mixing, heating may be performed using a heating medium in order to increase the solubility of the resin, and a chiller may be used to suppress heat of stirring.

  The present invention also applies a varnish in which the above components (A) to (E) and other optional components are dispersed and dissolved in an organic solvent to a release film or the like by a method such as a dispenser, coater, dipping, spraying or the like. The hot melt adhesive sheet can be obtained by forming into a sheet and removing the solvent at room temperature or by heat drying, vacuum drying or the like.

  At this time, the thickness of the hot-melt adhesive sheet is obtained by molding to an arbitrary thickness according to the purpose, but is preferably 5 to 300 μm, more preferably 20 to 200 μm.

  The hot-melt adhesive composition of the present invention adheres various substrates such as engineering plastics, metals, and glass to an object to be bonded. Therefore, this adhesive composition is used for electrolyte films, general-purpose plastic films such as polyolefins, polyesters, etc. It is possible to manufacture a laminate in which an engineering plastic film such as is adhered between layers.

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

(Examples 1-10, Comparative Examples 1-11)
Components (A) to (E) were mixed in toluene so as to have the compositions shown in Tables 1 to 4 and dissolved at 25 ° C. over 1 hour. Dispersion was used for dissolution, and stirring was performed at a rotational speed of 1000 rpm to prepare a resin varnish (hot melt resin composition).

  The obtained resin varnish was coated on a release film made of polyethylene terephthalate (PET) (Fujimori Kogyo, trade name: NSD; thickness 38 μm) and 1 at room temperature (20-25 ° C.) while ventilating in a fume hood. Dry for hours. After drying at room temperature, it was again dried at 40 ° C. for 1 hour to obtain a hot melt adhesive sheet having a thickness of 150 μm.

The materials used here are as follows.
(A) Elastomer (A1) Styrenic elastomer (Kuraray Co., Ltd., product name: Septon 4033)
(CA1) Thermoplastic Urethane Elastomer (Product name: Milactra, manufactured by Nihon Miractran)

(B) Base resin (B1) Polyphenylene ether (Product name: Noryl SA90 manufactured by SABIC)
(CB1) polyarylate (product name: U-100, manufactured by Unitika Ltd.)

(C) Tackifier 1
(C1) Hydrocarbon resin (Product name: T-REZ RC115 manufactured by TonenGeneral Sekiyu KK)
(C2) Hydrogenated hydrocarbon resin (product name: T-REZ HA125, manufactured by TonenGeneral Sekiyu KK)
(CC1) Coumarone (product name: V-120 manufactured by Nikkaku Chemical Co., Ltd.)

(D) Tackifier 2
(D1) Rosin ester (Product name: Pencel D-125, manufactured by Arakawa Chemical Co., Ltd.)
(CD1) Terpenephenol (Product name: YS Polystar T115, manufactured by Yasuhara Chemical Co., Ltd.)

(E) Filler (E1) Talc (Product name: Talc SSS, manufactured by Nippon Talc Co., Ltd.)

  Moreover, about the obtained hot-melt-adhesive sheet, the evaluation test of a characteristic is done as follows and the result is combined with Tables 1-4, and is shown.

[Flexibility evaluation]
(1) Preparation of test piece The hot melt adhesive sheet obtained in each example was pressed for 15 seconds with a heat press adjusted to a board surface temperature of 150 ° C. (press pressure: 1.0 MPa). Got.

(2) Measurement of tensile elastic modulus With respect to this test piece, the tensile elastic modulus at room temperature of 25 ° C was measured using DMS (DMS6100 manufactured by Seiko Instruments Inc.), and the flexibility was evaluated.

[Shear test]
(1) Preparation of test piece A hot melt adhesive sheet obtained in each example was cut into 1 cm × 1 cm, and a polyethylene naphthalate film (PEN film), a polypropylene film (PP film) and an electrolyte membrane cut into 3 cm × 1 cm were obtained. Three kinds of laminated sheets each obtained by laminating on both sides were obtained, and these were pressed for 15 seconds with a heat press adjusted to a board surface temperature of 150 ° C. (press pressure: 1.0 MPa) to obtain a test piece for adhesion evaluation. .

  The central part of the test piece in the longitudinal direction is an adhesive part laminated in three layers, and 2 cm × 1 cm at both ends from the central part without the adhesive layer is a two-layer only of a polyethylene naphthalate film, a polypropylene film or an electrolyte film. Structure.

  The above-mentioned polypropylene film is Toray (trade name; thickness: 50 μm) manufactured by Toray, the polyethylene naphthalate film is Teonex Q51 (trade name: thickness: 150 μm) manufactured by Teijin DuPont Films, and the electrolyte membrane is DuPont. Nafion NRE-212 (trade name; thickness: 50 μm) was used.

The shear measurement device was an autograph (manufactured by Shimadzu Corporation), and the shear rate was set to 5 mm / min and measured. The measurement environment was the following three conditions.
Room temperature: 25 ° C, humidity 60% RH
High temperature: 110 ° C, humidity 10% RH or less Low temperature: -30 ° C, humidity 90% RH or more

(3) Hot water resistance test (after hot water immersion treatment)
In order to confirm the hot-water adhesive property of the hot-melt adhesive, the test pieces were immersed in pure water and dilute sulfuric acid (pH 3), respectively sealed, and treated in an oven at 98 ° C. for 250 hours. After the treatment, the test piece was placed on a water absorbent sheet and treated in a drying furnace at 50 ° C. for 1 hour. The shear measurement device was an autograph (manufactured by Shimadzu Corporation), and the shear rate was set to 5 mm / min and measured. The measurement environment was normal temperature (25 ° C.) and humidity 60% RH.

[Comprehensive judgment]
(E) Those without a filler have a tensile modulus of 300 MPa or less, a shear test is room temperature, 5 MPa at −30 ° C., 2.5 MPa or more at 110 ° C., and a shear test after a hot water test is 5 MPa or more passes. did.

  (E) Those with fillers have a tensile modulus of 500 MPa or less, a shear test at room temperature, 5 MPa at −30 ° C., 3.5 MPa or more at 110 ° C., and a shear test after a hot water test of 5 MPa or more did. Was passed.

  As described above, according to the present invention, various materials can be bonded by a simple operation of being melted by heating and then cooled, and have good adhesiveness that can be stably bonded even when exposed to high temperatures. I understood.

Claims (6)

(A) 100 parts by mass of a styrene elastomer,
(B) polyether resin 0.5 to 20 parts by mass;
(C) 0.5 to 20 parts by mass of a hydrocarbon-based tackifier,
(D) 0.5-20 parts by mass of a rosin tackifier,
A hot melt adhesive composition comprising:   The hot melt adhesive composition according to claim 1, wherein the (A) styrene elastomer is polystyrene-poly (ethylene-ethylene / propylene) -polystyrene (SEEPS).   The hot melt adhesive composition according to claim 1 or 2, wherein the (B) polyether-based resin is polyphenylene ether.   Furthermore, the hot-melt-adhesive composition of any one of Claims 1-3 which contains 1-50 mass parts of (E) fillers.   It is a sheet-like molded product using the hot-melt-adhesive composition of any one of Claims 1-4, The hot-melt-adhesive sheet characterized by the above-mentioned.   The laminated body which has adhere | attached the base material and the adhesion target object through the hot-melt-adhesive composition of any one of Claims 1-4.