WO2021161735A1

WO2021161735A1 - Polyolefin-based adhesive composition

Info

Publication number: WO2021161735A1
Application number: PCT/JP2021/001655
Authority: WO
Inventors: 知佳高田; 健二柏原
Original assignee: 東洋紡株式会社
Priority date: 2020-02-14
Filing date: 2021-01-19
Publication date: 2021-08-19
Also published as: JPWO2021161735A1; TW202132518A

Abstract

[Problem] To provide an adhesive composition which exhibits satisfactory adhesiveness to a polyolefin resin base and a material of different kind and with which laminating is possible at low temperatures. [Solution] An adhesive composition comprising an acid-modified polyolefin (A), a diene-based polymer (B), and a tackifier (C).

Description

Polyolefin-based adhesive composition

The present invention relates to an adhesive composition and a laminate.

Polyolefin-based resins such as polypropylene and polyethylene are inexpensive and have many excellent properties such as moldability, chemical resistance, water resistance, and electrical properties, and are therefore widely used as sheets, films, molded products, and the like in recent years.
However, unlike polar substrates such as polyurethane resins, polyamide resins, acrylic resins, and polyester resins, the substrates made of these polyolefin resins (hereinafter referred to as polyolefin substrates) are non-polar and crystalline. , Has the drawback of being difficult to paint and bond.
Recently, there has been an increasing demand for excellent adhesion between polyolefin-based substrates, as well as polar plastic substrates such as vinyl chloride (PVC) and polyester, and dissimilar materials such as metals. ..
As the main component of the polyolefin-based resin base material and the adhesive between dissimilar materials, a thermoplastic copolymer linear polymer is used as a base resin, and a modified polyolefin resin and a tackifier (Patent Document 1), modified polyolefin, and the like. Those made of an aliphatic polyester resin, an olefin resin and a tackifier (Patent Document 2), those made of a modified polyolefin, a thermoplastic resin and a tackifier (Patent Document 3) and the like have been proposed.

JP-A-2004-292716 JP 2014-234400 JP 2016-89060

However, all of the proposed adhesive compositions have good adhesiveness between the polyolefin resin base material and the metal (aluminium) or between the polyolefin resin base material and the polyester (PET) base material, but aluminum. The adhesiveness between the base material other than PET and the polyolefin resin base material is unknown. In addition, all of them are hot melt adhesives, and adhesion at a high temperature of 180 ° C is indispensable. The present invention provides an adhesive composition that exhibits good adhesiveness between a polyolefin resin base material and a polar plastic base material or a metal base material other than the polyolefin resin base material and can be bonded at a low temperature. be.

In order to achieve the above problems, the present inventors have diligently studied and found that a combination of a specific modified polyolefin, a diene polymer and a tackifier is effective, and have proposed the following inventions. That is, the present invention has the following configuration.
(1) It contains an acid-modified polyolefin (A), a diene polymer (B) and a tackifier (C), and the mass ratio of the diene polymer (B) to 100 parts by mass of the acid-modified polyolefin (A) is An adhesive composition in which the mass ratio of the tackifier (C) is 1 part by mass or more and 100 parts by mass or less, and the mass ratio of the tackifier (C) is 1 part by mass or more and 100 parts by mass or less.
(2) The adhesive composition according to (1), wherein the acid value of the acid-modified polyolefin (A) is 2 to 50 mgKOH / g.
(3) The adhesive composition according to either (1) or (2), which further contains a solvent (D).
(4) The adhesive composition according to any one of (1) to (3), wherein the solvent (D) contains an alicyclic hydrocarbon solvent (D1) and an ester solvent or a ketone solvent (D2).
(5) The mass ratio of the alicyclic hydrocarbon solvent (D1) to the ester solvent or the ketone solvent (D2) is (D1) / (D2) = 95/5 to 50/50, (1) to The adhesive composition according to any one of (4).
(6) The adhesive composition according to any one of (1) to (5), which comprises a curing agent (E).
(7) The adhesive composition according to any one of (1) to (6), which is used for adhering the polyolefin resin base material 1 and the base material 2 different from the base material 1.
(8) A laminate of a polyolefin resin base material 1 adhered by the adhesive composition according to any one of (1) to (6) and a base material 2 different from the base material 1.

The adhesive composition of the present invention contains an acid-modified polyolefin, a diene polymer and a tackifier, and comprises a non-polar substrate such as polyolefin, an acrylonitrile-butadiene-styrene copolymer (ABS), and a polycarbonate (PC). It has excellent adhesiveness to polar substrates such as, and other dissimilar substrates such as metals, and has good extensibility. Further, since the coating can be performed by dry laminating, the equipment cost can be reduced and the film thickness can be reduced. Further, excellent adhesiveness is exhibited even when heat-bonding is performed at a low temperature such as 90 ° C. or lower, which has a small effect of heat shrinkage of the polyolefin base material.

The adhesive composition of the present invention exhibits good adhesion not only to a polyolefin base material but also to a base material such as ABS resin, polycarbonate, polyethylene terephthalate (PET), polyvinyl chloride (PVC), acrylic resin, and aluminum. , Useful as an adhesive for multi-base materials.

Hereinafter, embodiments of the present invention will be described in detail.

<Acid-modified polyolefin (A)>
The acid-modified polyolefin (A) used in the present invention is not limited, but is preferably obtained by grafting at least one of α, β-unsaturated carboxylic acid and an acid anhydride thereof on polypropylene.

As the polypropylene, homopolypropylene can be particularly preferably used, but a propylene / α-olefin copolymer can also be used. The propylene / α-olefin copolymer is obtained by copolymerizing propylene as a main component with α-olefin. As the α-olefin, for example, one or several kinds of ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene, vinyl acetate and the like can be used. Among these α-olefins, ethylene and 1-butene are preferable, and 1-butene is particularly preferable.

The acid-modified polyolefin (A) preferably contains 60 mol% or more of propylene as an olefin component. It is more preferably 70 mol% or more, still more preferably 80 mol% or more. More preferably, it is 90 mol% or more. The higher the propylene content, the better the adhesion to the polypropylene substrate.

The preferred range of the molar ratio of propylene to 1-butene of the acid-modified polyolefin (A) is propylene / 1-butene = 99 to 60/1 to 40, more preferably 98 to 65/2 to 35, and even more preferably 98 to 65/2 to 35. It is 90 to 70/10 to 30. When the molar ratio of propylene is 60% or more, excellent adhesiveness to the polyolefin base material can be exhibited.

Examples of at least one of α, β-unsaturated carboxylic acid and its acid anhydride include maleic acid, itaconic acid, citraconic acid and their acid anhydrides. Among these, acid anhydride is preferable, and maleic anhydride is more preferable. Specific examples of the acid-modified polyolefin (A) include maleic anhydride-modified polypropylene, maleic anhydride-modified propylene / ethylene copolymer, maleic anhydride-modified propylene / 1-butene copolymer, and maleic anhydride-modified propylene. Examples thereof include ethylene / 1-butene copolymers, and these acid-modified polyolefins can be used alone or in combination of two or more. Of these, maleic anhydride-modified polypropylene is preferable.

The acid value of the acid-modified polyolefin (A) is preferably in the range of 2 to 50 mgKOH / g. It is more preferably in the range of 3 to 40 mgKOH / g, further preferably in the range of 5 to 30 mgKOH / g, and particularly preferably in the range of 10 to 20 mgKOH / g. When the acid value is 2 mgKOH / g or more, the molecular weight is high and the extensibility of the adhesive layer is exhibited well. On the other hand, when the acid value is 50 mgKOH / g or less, the molecular weight is low and the solution stability at low temperature tends to be good.

The crystallinity of the acid-modified polyolefin (A) is preferably in the range of 12 to 70%. It is more preferably in the range of 15 to 60, and most preferably in the range of 18 to 50%. When it is more than the above value, the cohesive force derived from the crystal becomes strong, and the adhesiveness with the substrate is excellent. On the other hand, when the value is less than the above value, the cohesive force derived from the crystal is moderate and the adhesiveness is good.

The amount of heat of fusion of the modified polyolefin (A) is preferably in the range of 25 to 80 J / g. It is more preferably in the range of 28 to 75 J / g, and most preferably in the range of 30 to 70 J / g. When it is more than the above value, the cohesive force derived from the crystal becomes strong and the adhesiveness is excellent. On the other hand, when it is less than the above value, the cohesive force derived from the crystal is moderate and the adhesiveness is good.

The acid-modified polyolefin (A) may be chlorinated.

The melting point (Tm) of the acid-modified polyolefin (A) is preferably 50 ° C. or higher and 130 ° C. or lower. It is more preferably 55 ° C. or higher, and even more preferably 60 ° C. or higher. Further, it is more preferably 125 ° C. or lower, further preferably less than 120 ° C., more preferably 115 ° C. or lower, and most preferably 110 ° C. or lower. At 50 ° C. or higher, the cohesive force derived from the crystals becomes strong and the adhesiveness is good. On the other hand, at 130 ° C. or lower, the solution stability and fluidity are good, and the operability at the time of bonding is excellent. In addition, it is possible even if the temperature at the time of bonding is low.

The amount of heat of fusion of the acid-modified polyolefin (A) is preferably in the range of 20 to 70 J / g. It is more preferably in the range of 25 to 65 J / g, and most preferably in the range of 30 to 60 J / g. When it is 20 J / g or more, the cohesive force derived from the crystal becomes strong and the adhesiveness is excellent. On the other hand, at 70 J / g or less, the adhesiveness is excellent because it is flexible and can follow the base material.

The weight average molecular weight (Mw) of the acid-modified polyolefin (A) is preferably in the range of 10,000 to 200,000. It is more preferably in the range of 20,000 to 180,000, further preferably in the range of 30,000 to 160,000, particularly preferably in the range of 35,000 to 140,000, and most preferably in the range of 40. It ranges from 000 to 120,000. When it is 10,000 or more, the cohesive force becomes strong and the adhesiveness is good.
On the other hand, when it is 200,000 or less, the fluidity is high, the operability at the time of adhesion is good, and the solution stability at a low temperature is good.

The method for producing the acid-modified polyolefin (A) is not particularly limited, and for example, a radical graft reaction (that is, a radical species is generated for a polymer serving as a main chain, and the radical species is used as a polymerization initiation point to generate an unsaturated carboxylic acid and (Reaction of graft polymerization of acid anhydride), and the like.

The radical generator is not particularly limited, but it is preferable to use an organic peroxide. The organic peroxide is not particularly limited, but is not particularly limited, but is di-tert-butylperoxyphthalate, tert-butylhydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butylperoxybenzoate, tert-butylperoxy-. Peroxides such as 2-ethylhexanoate, tert-butylperoxypivalate, methylethylketone peroxide, di-tert-butyl peroxide, lauroyl peroxide; azobisisobutyronitrile, azobisisopropionitrile, etc. Examples include azonitriles.

These acid-modified polyolefins (A) may be used alone or in combination of two or more.

<Diene polymer (B)>
The adhesive composition of the present invention contains a diene polymer (B). By containing the diene polymer, the internal stress after forming the adhesive can be reduced and the adhesiveness with the base material can be improved.

The diene-based polymer is a polymer containing a diene-based monomer as a constituent unit. The diene polymer is not particularly limited, and examples thereof include ethylene-propylene-diene rubber, polybutadiene, and isoprene rubber. Moreover, these may be denatured. These may be used individually by 1 type, and may be used in combination of 2 or more type.

The number average molecular weight (Mn) of the diene polymer (B) is preferably 1,000 or more and 100,000 or less. More preferably 2,000 or more and 80,000 or less, still more preferably 3,000 or more and 60,000 or less, particularly preferably 4,000 or more and 50,000, 0 or less, and even more preferably 4,500 or more and 40. It is 000 or less, most preferably 4,800 or more and 20,000 or less. When it is 1,000 or more, the compatibility with the acid-modified polyolefin (A) is moderate, the stress relaxation effect is exhibited, and the adhesiveness tends to be good. Further, when it is 100,000 or less, the compatibility with the acid-modified polyolefin (A) is remarkably improved.

The content of the diene polymer (B) is 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by weight of the acid-modified polyolefin (A). It is more preferably 2 parts by mass or more and 95 parts by mass or less, further preferably 5 parts by mass or more and 90 parts by mass or less, particularly preferably 8 parts by mass or more and 85 parts by mass or less, and more preferably 10 parts by mass or more and 80 parts by mass or less. Hereinafter, it is most preferably 12 parts by mass or more and 75 parts by mass or less. When it is 1 part by mass or more, the stress relaxation effect is exhibited and the adhesiveness tends to be good. Further, when the amount is 100 parts by mass or less, the cohesive force of the coating film is moderate and the adhesiveness is improved.

The shape of the diene polymer (B) is not particularly limited, but a semi-solid or liquid polymer at room temperature is particularly preferable. The compatibility with the acid-modified polyolefin (A) is good, and the solution stability at low temperature is also good.
<Adhesive imparting agent (C)>
The adhesive composition of the present invention contains a tackifier (C). By containing the tackifier, the adhesiveness of the surface can be maintained after the adhesive is formed, and the adhesiveness with the substrate can be improved.

The content of the tackifier (C) used in the present invention is 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by weight of the acid-modified polyolefin (A). More preferably, it is 2 parts by mass or more and 95 parts by mass or less, more preferably 5 parts by mass or more and 90 parts by mass or less, particularly preferably 8 or more and 85 parts by mass or less, and more preferably 10 parts by mass or more and 80 parts by mass or less. It is preferably 15 parts by mass or more and 75 parts by mass or less. Further, when it is 1 part by mass or more, the viscosity of the solution is moderate and the stability of the solution is good. On the other hand, when it is 100 parts by mass or less, the adhesiveness of the surface is moderate and the adhesiveness is exhibited well.

The softening point of the tackifier (C) used in the present invention is preferably 60 ° C. or higher. It is more preferably 65 ° C. or higher, and even more preferably 70 ° C. or higher. Further, it is preferably 150 ° C. or lower, more preferably 138 ° C. or lower, particularly preferably 135 ° C. or lower, more preferably 130 ° C. or lower, and most preferably 128 ° C. or lower. When the softening point is 60 ° C. or higher, the tackifier at room temperature does not easily bleed out to the surface, resulting in a smooth surface and good adhesiveness. Further, when the temperature is 140 ° C. or lower, tackiness at room temperature occurs, and the adhesiveness is good. These may be used alone or in combination of two or more.

The tackifier (C) of the present invention can improve compatibility and storage stability while maintaining good adhesiveness by using a tackifier having different softening points in an appropriate blending ratio. For example, in the present application, a tackifier (C1) having a softening point of 110 ° C. or higher and 150 ° C. or lower and a tackifier (C2) having a softening point of 75 ° C. or higher and lower than 110 ° C. can be combined. The tackifier (C1) is particularly preferably 115 ° C. or higher and 140 ° C. or lower, and most preferably 120 ° C. or higher and 130 ° C. or lower. The pressure-sensitive adhesive (C2) is particularly preferably 75 ° C. or higher and 100 ° C. or lower, and most preferably 80 ° C. or higher and 95 ° C. or lower. By combining the above two types, it is possible to improve the adhesiveness while preventing bleeding out. The mass ratio of (C1) to (C2) is preferably (C1) / (C2) = 90 to 50/10 to 50, more preferably 85 to 60/15 to 40, and 78 to 65/22 to 35. More preferred. Within the above range, good compatibility and storage stability can be obtained, and good adhesiveness can be exhibited.

The tackifier (C) used in the present invention includes various types, and for example, petroleum resin (aliphatic, alicyclic, aromatic, etc.) and terpene resin (α-pinene, β-). Polymers such as pinen and limonene), aromatic hydrocarbon-modified terpene resins, rosin-based resins (gamrosin, tall oil rosin, wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, rosin ester, etc.), Examples thereof include terpene phenol resins, and rosin-based resins are particularly preferable. These may be used alone or in combination of two or more.

The tackifier (C) used in the present invention may have a hydroxyl group. For example, pine crystal KE-359 having a hydroxyl value of 38 to 47 mgKOH / g can be used.

<Solvent (D)>
The adhesive composition of the present invention can contain a solvent (D). The solvent (D) is not particularly limited as long as it can dissolve or disperse the acid-modified polyolefin (A), the diene polymer (B) and the tackifier (C), but the alicyclic hydrocarbon solvent (D1), An ester solvent or a ketone solvent (D2) is preferable.
For example, examples of the alicyclic hydrocarbon solvent (D1) include cyclohexane, methylcyclohexane, and ethylcyclohexane. Examples of the ester solvent or the ketone solvent (D2) include ethyl acetate, propyl acetate, butyl acetate, and methyl ethyl ketone. Of these, cyclohexane and butyl acetate are preferable. These may be used alone, or two or more kinds may be used in any combination.

As the solvent (D) used in the present invention, a mixed solvent containing an alicyclic hydrocarbon solvent (D1) and an ester solvent or a ketone solvent (D2) can be used. By using a mixed solvent of an alicyclic hydrocarbon solvent and an ester solvent or a ketone solvent, the solubility of the adhesive composition can be improved.

When the mixed solvent is used, the mass ratio of the alicyclic hydrocarbon solvent (D1) to the ester solvent or the ketone solvent (D2) is (D1) / (D2) = 99/1 to 50/50. preferable. It is more preferably 95/5 to 60/40, and particularly preferably 90/10 to 70/30. If the amount of alicyclic hydrocarbon (D1) is larger than the above range, the viscosity may be high and coating unevenness may occur, resulting in a decrease in adhesiveness. If the alicyclic hydrocarbon (D1) in the above range is contained, the solubility of the resin is good.

The solvent (D) can be contained in the range of 10 to 2000 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin (A). It is preferably 25 parts by mass or more and 1500 parts by mass or less, more preferably 50 parts by mass or more and 1000 parts by mass or less, further preferably 100 parts by mass or more and 900 parts by mass or less, and more preferably 100 parts by mass or more and 800 parts by mass or less. Is. If it is within the above range, it is advantageous in terms of manufacturing cost and transportation cost.

<Curing agent (E)>
The curing agent (E) used in the present invention is not particularly limited, but an epoxy compound, an isocyanate compound, a compound containing an oxazoline group or a carbodiimide group, a silane coupling agent, or the like can be appropriately used, which is good for a resin substrate. An isocyanate compound is preferable in terms of good adhesiveness.

The isocyanate compound used in the present invention is not particularly limited, and diisocyanate, triisocyanate and compounds derived from these can be preferably used.
For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, isophorone diisocyanate, 1,5-naphthalenediisocyanate, hexamethylene diisocyanate, bis (4-isocyanate cyclohexyl) methane, or water. Examples thereof include diisocyanates such as anated diphenylmethane diisocyanate. Further, a compound derived from the diisocyanate, that is, an isocyanurate form of the diisocyanate, an adduct form, a biuret type, a uretdione form, an allophanate form, a prepolymer having an isocyanate residue (a low polymer obtained from a diisocyanate and a polyol), and a tri. Examples thereof include glycidyl isocyanurate or a complex thereof. These may be used alone, or two or more kinds may be used in any combination.

Among the isocyanate compounds used in the present invention, those having an isocyanurate form of the diisocyanate compound are preferable because of their excellent adhesiveness to the resin substrate.

The epoxy curing agent used in the present invention is not particularly limited, and an epoxy resin and a compound derived from these can be preferably used, and a bifunctional epoxy is more preferable. Specific examples include glycidylamine type epoxy resin, glycidyl ether type epoxy resin such as bisphenol A, phenol novolac type epoxy resin, and cresol novolac type epoxy resin, glycidyl ester type such as hexahydrophthalic acid glycidyl ester, and dimer acid glycidyl ester, or glycidyl ester type. Examples thereof include alicyclic or aliphatic epoxisides such as 3,4-epoxycyclohexylmethylcarboxylate, epoxidized polybutadiene, and epoxidized soybean oil, and one type may be used alone or two or more types may be used in combination.

The amount of the curing agent (E) used in the present invention is 100 parts by mass based on the total solid content of the adhesive such as the acid-modified polyolefin (A), the diene polymer (B) and the tackifier (C). It is preferably 10 parts by mass or less. In particular, the range of 8 parts by mass or less is preferable, more preferably 6 parts by mass or less, further preferably 4 parts by mass or less, and particularly preferably 3 parts by mass or less. When a curing agent is added, a sufficient crosslinked structure is obtained, and the heat resistance becomes better. When it is 10 parts by mass or less, the pot life is extended and the coating stability is improved. In addition, the curing shrinkage is reduced, and the adhesiveness to the substrate is improved.

The adhesive composition according to the present invention contains various plasticizers and curing agents in addition to the acid-modified polyolefin (A), the diene polymer (B), and the tackifier (C), as long as the performance of the present invention is not impaired. Additives such as accelerators, flame retardants, pigments and anti-blocking agents can be blended and used.

<Adhesive composition>
When the adhesive composition of the present invention contains a solvent (D), the total amount of the acid-modified polyolefin (A), the diene polymer (B) and the tackifier (C) in the adhesive composition / solvent (D) ) The amount is preferably 5/95 to 100/0. It is more preferably 7/93 to 40/60, further preferably 10/90 to 35/65, and particularly preferably 12/88 to 30/70. Within the above range, storage stability tends to be good, and coatability tends to be good.

<Laminated body>
The laminate of the present invention is a laminate of a polyolefin resin base material 1 and a polyolefin base material 1 or a dissimilar base material 2 with the adhesive composition according to the present invention. The dissimilar base material 2 is a base material different from the polyolefin base material 1. For example, if the polyolefin base material 1 is polypropylene, the dissimilar base material 2 is an ABS resin other than polypropylene, polycarbonate, or the like.

The above-mentioned laminate of the present invention includes, for example, automobile parts such as bumpers, instrument panels, trims, and garnishes, vehicle parts such as Shinkansen interior materials, TVs, washing machine tanks, refrigerator parts, air conditioner parts, and vacuum cleaner parts. It is useful for home appliance parts such as, mobile devices such as mobile phone terminals and laptop computers, communication devices, touch panels of various devices, and daily necessities.

As a method of laminating, a conventionally known laminating manufacturing technique can be used. For example, although not particularly limited, the adhesive composition is applied to the surface of the base material using an appropriate coating means such as an applicator or a bar coater, and dried. After drying, while the layer of the adhesive composition (adhesive layer) formed on the surface of the base material is in a molten state, the other base material is laminated and adhered (laminate adhesion, heat seal adhesion) to the coated surface. Can be obtained as a laminate. Sufficient adhesiveness can be ensured regardless of the method for producing the laminate, which is either laminate adhesion or heat seal adhesion.
The thickness of the adhesive layer formed by the adhesive composition is not particularly limited, but is preferably 0.5 to 60 μm, more preferably 1 to 50 μm, and further preferably 2 to 40 μm. preferable.

<Polyolefin resin base material (film)>
The polyolefin resin base material may be appropriately selected from conventionally known polyolefin resins. For example, although not particularly limited, polyethylene, polypropylene, ethylene-propylene copolymer and the like can be used. Above all, it is preferable to use a polypropylene non-stretched film (hereinafter, also referred to as CPP). The thickness is not particularly limited, but is preferably 20 to 100 μm, more preferably 25 to 95 μm, and even more preferably 30 to 90 μm. If necessary, the polyolefin resin base material may be blended with pigments or various additives, or may be surface-treated.

<Polyolefin resin base material (molded body)>
The polyolefin resin base material may be appropriately selected from conventionally known polyolefin resins. For example, although not particularly limited, polyethylene, polypropylene, ethylene-propylene copolymer and the like can be used. Above all, the use of a polypropylene resin base material is preferable. The thickness is not particularly limited, but is preferably 0.1 to 100 mm, more preferably 0.5 to 90 mm, and even more preferably 1 to 80 mm. If necessary, the polyolefin resin base material may be blended with pigments or various additives, or may be surface-treated.

<Other dissimilar base materials (molded body)>
As the dissimilar base material, ABS resin, polycarbonate, polyvinyl chloride, acrylic resin, urethane resin, Al foil and the like can be used. The thickness thereof is not particularly limited, but is preferably 0.1 to 100 mm, more preferably 0.5 to 90 mm, and even more preferably 1 to 80 mm. It may be surface-treated or may remain untreated. In either case, the same effect can be achieved.

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

<Production example of acid-modified polyolefin (A)>
Manufacturing example 1
To 1 L autoclave, 100 parts by mass of polypropylene (Tm: 80 ° C., weight average molecular weight 135,000), 150 parts by mass of toluene, 8.5 parts by mass of maleic anhydride, and 4 parts by mass of di-tert-butyl peroxide were added to 140 parts. After the temperature was raised to ° C., the mixture was further stirred for 1 hour. After completion of the reaction, the reaction solution was poured into a large amount of methyl ethyl ketone to precipitate a resin. The resin was further washed with methyl ethyl ketone several times to remove unreacted maleic anhydride. By drying the obtained resin under reduced pressure, maleic anhydride-modified polypropylene (A-1, acid value 12 mgKOH / g-resin, weight average molecular weight 60,000, Tm80 ° C., heat of fusion 31 J / g), which is an acid-modified polyolefin. Got

Manufacturing example 2
By making the same as Production Example 1 except that the polypropylene used in Production Example 1 was changed to another polypropylene (Tm: 80 ° C., weight average molecular weight 45,000), maleic anhydride-modified polypropylene (maleic anhydride-modified polypropylene), which is an acid-modified polyolefin, was used. A-2, acid value 12 mgKOH / g-resin, weight average molecular weight 45,000, Tm 80 ° C., heat of fusion 34 J / g) were obtained.

Manufacturing example 3
The polypropylene used in Production Example 1 is an acid-modified polyolefin in the same manner as in Production Example 1 except that the polypropylene is changed to a propylene-butene copolymer (Tm: 83 ° C., 80 mol% propylene, 20 mol% butene). A maleic anhydride-modified propylene-butene copolymer (A-3, acid value 12 mgKOH / g-resin, weight average molecular weight 90,000, Tm 80 ° C., heat of fusion 48 J / g) was obtained.

Manufacturing example 4
Production Example 1 except that the polypropylene used in Production Example 1 was changed to a propylene-butene copolymer (Tm: 98 ° C., 85 mol% propylene, 15 mol% butene) and maleic anhydride was changed to 20 parts by mass. Maleic anhydride-modified propylene-butene copolymer (A-4, acid value 25 mgKOH / g-resin, weight average molecular weight 60,000, Tm95 ° C., heat of fusion 61 J / g) ) Was obtained.

Example 1
In a 500 ml four-necked flask equipped with a water-cooled reflux condenser and a stirrer, 100 parts by mass of the maleic anhydride-modified polypropylene (A-1) obtained in Production Example 1 and 20 parts of a diene elastomer (B-1) were placed. Charge 70 parts by mass, 35 parts by mass of the tackifier (C-1), 15 parts by mass of (C-2), 432 parts by mass of cyclohexane (D1) and 48 parts by mass of butyl acetate (D2), and stir. The temperature was raised to ° C., stirring was continued for 1 hour, and then the mixture was cooled to obtain an adhesive composition 1. Using this adhesive composition 1, a laminate was prepared by the following method.

Fabrication of a laminate of a polyolefin resin base material and a polyolefin resin base material, or other dissimilar base materials (heat seal adhesion)
A non-stretched polypropylene film (Pyrene (registered trademark) film CT manufactured by Toyobo Co., Ltd., thickness 80 μm) (hereinafter, also referred to as CPP) was used as the polyolefin resin base material. The obtained adhesive composition was applied to a polyolefin resin base material using an applicator after adjusting the film thickness of the adhesive layer after drying to be about 20 μm. The coated surface was dried in an atmosphere of 100 ° C. for 3 minutes using a warm air dryer to obtain a polyolefin resin base material on which an adhesive layer having a film thickness of about 20 μm was laminated. Polypropylene (PP) test plate (manufactured by Japan Test Panel Co., Ltd., thickness 2 mm), ABS test plate (manufactured by Japan Test Panel Co., Ltd., thickness 2 mm), polycarbonate (PC) test plate (manufactured by Japan Test Panel Co., Ltd., thickness 2 mm) on the surface of the adhesive layer. (2 mm thick), and using a heat seal tester (TP-701-B) manufactured by Tester Sangyo Co., Ltd., at a heat seal temperature of 90 ° C (55 ° C on the test plate side), 0.3 MPa for 15 seconds. The laminate was obtained by laminating and curing at room temperature for 1 day.
The adhesiveness of the obtained laminate was evaluated. The results are shown in Table 1.

(Examples 2 to 11, Comparative Examples 1 to 4)
The acid-modified polyolefin (A), the diene polymer (B), the tackifier (C) and the curing agent (E) were changed as shown in Table 1, and the adhesive compositions 2 to 2 were modified in the same manner as in Example 1. 15 was prepared. Using the obtained adhesive compositions 2 to 15, a laminate was prepared in the same manner as in Example 1, and the adhesiveness was evaluated. The evaluation results are shown in Table 1.

The diene-based polymer (B) used in Table 1 is as follows.
B-1: Trilene (registered trademark) 65 (Mn: 17,000) manufactured by LION ELASTOMERS
B-2: Synthomer Lithene ultra (registered trademark) N4-5000-15MA (Mn: 5750, acid value: 75 mgKOH / g-resin)
B-3: Synthomer Lithene ultra (registered trademark) N4-5000 (Mn: 5000)

The tackifier (C) used in Table 1 is as follows.
C-1: Harima Chemicals, Inc. Haritac (registered trademark) FK125 (rosin ester adhesive, softening temperature 125 ° C)
C-2: Harima Chemicals, Inc. Haritac (registered trademark) F85 (rosin ester-based tackifier, softening temperature 85 ° C)
C-3: Pine Crystal (registered trademark) KE-311 manufactured by Arakawa Chemical Co., Ltd. (rosin-based adhesive, softening temperature 95 ° C)
C-4: Pine Crystal (registered trademark) KE-359 manufactured by Arakawa Chemical Co., Ltd. (rosin-based tackifier, softening temperature 100 ° C., hydroxylation: 37-48 mgKOH / g-resin)

The curing agent (E) used in Table 1 is as follows.
E-1: Tosoh Corporation (registered trademark) Coronate HX

The acid-modified polyolefins, diene-based polymers, tackifiers, adhesive compositions and laminates obtained as described above were analyzed, measured and evaluated based on the following methods.
<Measurement of acid value>
The acid value (mgKOH / g-resin) in the present invention is the amount of KOH required to neutralize 1 g of the acid-modified polyolefin (A), and is according to the test method of JIS K0070 (1992). It was measured. Specifically, after dissolving 1 g of acid-modified polyolefin in 100 g of xylene whose temperature has been adjusted to 100 ° C., a 0.1 mol / L potassium hydroxide ethanol solution using phenolphthalein as an indicator at the same temperature [trade name “0” .1 mol / L ethanolic potassium hydroxide solution ”, manufactured by Wako Pure Chemical Industries, Ltd.] was titrated. At this time, the acid value (mgKOH / g) was calculated by converting the amount of potassium hydroxide required for titration into mg.

<Measurement of number average molecular weight (Mn)>
The number average molecular weight in the present invention is a gel permeation chromatograph Alliance e2695 (hereinafter, GPC, standard substance: polystyrene resin, mobile phase: tetrahydrofuran, column: Shodex KF-806 + KF-803, column temperature: 40) manufactured by Japan Waters Co., Ltd. ° C., flow velocity: 1.0 ml / min, detector: photodiode array detector (wavelength 254 nm = ultraviolet rays)).

<Measurement of crystallinity>
The adhesive composition was applied to the surface of the Teflon (registered trademark) sheet using an applicator, dried, and then peeled off to obtain a film-like adhesive composition. After that, XRD measurement was performed under the following conditions. Measuring equipment: Rigaku Denki X-ray diffractometer RINT2500
Target: Cu
Tube voltage: 40kV
Tube current: 200mA
Collimator: 1mmφ
Slit: length 2 °, width 1/2 °
Light receiving part: Ni filter, scintillation counter Scanning range: 2θ / θ
The crystallinity was calculated from the obtained XRD diffraction peak.

<Measurement of melting point and heat of fusion>
The melting point and the amount of heat of melting in the present invention are determined by holding at −50 ° C. for 5 minutes using a differential scanning calorimeter (hereinafter, DSC, manufactured by TA Instruments Japan, Q-2000) and then 10 ° C./min. It is heated and melted at a rate, and after melting at 200 ° C, it is held at 200 ° C for 2 minutes, cooled to -50 ° C at a rate of 10 ° C / min, and then heated again at a rate of 10 ° C / min. It was measured from the top temperature and area of the melting peak when it was melted.

<Evaluation of adhesiveness>
The laminate was cut into strips of 15 mm, and the adhesiveness was evaluated by the following criteria by a 180 ° peel test.
The 180 ° peeling test conformed to the test method of ASTM-D1876-61, and the peeling strength at a tensile speed of 50 mm / min was measured in an environment of 25 ° C. using Tencilon RTM-100 manufactured by Orientec Corporation. The peel strength (N / 15 mm) between the dissimilar base material / polyolefin resin base material was taken as the average value of the two test values.

<Extensibility of coating film>
The extensibility of the coating film in the present invention was measured by preparing a cast film having a thickness of 50 μm and using Tencilon RTM-100 manufactured by Orientec Corporation under the condition of a tensile speed of 50 mm / min in an environment of 25 ° C. .. The cast film was prepared as follows. The obtained adhesive composition was applied to a Teflon sheet using an applicator after adjusting the film thickness of the adhesive layer after drying to 50 μm. The coated surface was dried in an atmosphere of 100 ° C. for 10 minutes using a warm air dryer to obtain a Teflon sheet on which an adhesive layer having a film thickness of 50 μm was laminated. The coating film was peeled off from the Teflon sheet, cut to 60 × 15 mm, the distance between chucks (the length of the initial coating film) was 30 mm, and the elongation was calculated from the following formula.
{(Length at break of coating film-Length of initial coating film) / Length of initial coating film} x 100 (%)

<Evaluation of heat resistance>
In the evaluation of heat resistance of the present invention, each laminate obtained by the above method was further stored at 80 ° C. for 10 days, and then a peeling test was carried out in the same manner as in the above evaluation of adhesiveness. The evaluation criteria are as follows.
⊚: Peeling strength of various base materials is 15N / 15mm or more 〇: Peeling strength of various base materials is 13N / 15mm or more and less than 15N / 15mm Δ: Peeling strength of various base materials is 11N / 15mm or more and less than 13N / 15mm X: Peeling strength of various substrates is less than 11N / 15mm

The adhesive composition of the present invention contains an acid-modified polyolefin, a diene polymer and a tackifier, and is suitable for adhesion not only to non-polar substrates such as polyolefins but also to other dissimilar substrates such as polar substrates and metals. Excellent. Further, since the coating can be performed by dry laminating, the equipment cost can be reduced and the film thickness can be reduced. Further, excellent adhesiveness is exhibited even by heat bonding at a low temperature such as 90 ° C. or lower, which has a small effect of heat shrinkage of the polyolefin base material, and the extensibility is also good. Therefore, the adhesive composition of the present invention can be widely used as an adhesive for various purposes such as for decorative films and paint films for bonding various types of base materials to each other.

Claims

It contains an acid-modified polyolefin (A), a diene polymer (B) and a tackifier (C), and the mass ratio of the diene polymer (B) is 1 part by mass with respect to 100 parts by mass of the acid-modified polyolefin (A). An adhesive composition having a mass ratio of 1 part by mass or more and 100 parts by mass or less of the tackifier (C).
The adhesive composition according to claim 1, wherein the acid value of the acid-modified polyolefin (A) is 2 to 50 mgKOH / g.
An adhesive composition containing an acid-modified polyolefin (A), a diene polymer (B), a tackifier (C) and a solvent (D).
The adhesive composition according to any one of claims 1 to 3, which contains a solvent (D) and the solvent (D) contains an alicyclic hydrocarbon solvent (D1) and an ester solvent or a ketone solvent (D2). ..
The adhesion according to claim 4, wherein the mass ratio of the alicyclic hydrocarbon solvent (D1) to the ester solvent or the ketone solvent (D2) is (D1) / (D2) = 95/5 to 50/50. Agent composition.
The adhesive composition according to any one of claims 1 to 5, which comprises a curing agent (E).
The adhesive composition according to any one of claims 1 to 6, which is used for adhering the polyolefin resin base material 1 and the base material 2 different from the base material 1.
A laminate of a polyolefin resin base material 1 adhered by the adhesive composition according to any one of claims 1 to 6 and a base material 2 different from the base material 1.