WO2019188858A1 - Modified polyolefin resin and use of same - Google Patents

Abstract

The present invention addresses the problem of providing a modified polyolefin resin which has excellent solution stability, while exhibiting good adhesion to a metal such as aluminum and to a polyolefin base material including a polyethylene base material. The present invention is a modified polyolefin resin which is a graft-modified product that is obtained by modifying a component (A), which is composed of a polyolefin resin that contains at least a copolymer a having an ethylene structural unit content of less than 50 mol% and a copolymer b having an ethylene structural unit content of 50 mol% or more, with a component (B), which is composed of a (meth)acrylic acid ester and an α, β-unsaturated carboxylic acid or a derivative thereof.

Description

Modified polyolefin resin and use thereof

The present invention relates to a modified polyolefin resin and its use.

Aluminum laminate films are widely used as packaging materials in various fields such as food, toiletries, pharmaceuticals, and electronic equipment parts because of their excellent light-shielding properties and oxygen / water vapor barrier properties. In these applications, a polyolefin resin is generally used for the innermost layer in order to seal the contents by adhering the end portions by heat sealing.

Among aluminum laminate film applications, especially for toiletries, it is common to use polyethylene, specifically linear low density polyethylene (hereinafter abbreviated as “LLDPE”), as the innermost layer of aluminum laminate films for refill pouches. is there. However, since polyolefin resins, especially polyethylene resins, have low polarity and are difficult to bond, the surface is subjected to surface treatment such as corona discharge treatment or plasma treatment and then aluminum is added via a polyester or polyurethane adhesive. Need to laminate with foil. However, the surface treatment such as corona discharge treatment has a problem that the number of steps increases and the effect decreases with time, so that stable adhesive strength cannot be obtained.

In addition to mechanical treatment such as corona discharge treatment and plasma treatment, chemical treatment using a primer or the like is performed as a surface treatment technology for improving the coating and adhesion of polyolefin substrates. As a primer for a polyolefin substrate, a modified polyolefin such as a chlorinated polyolefin or an acid-modified polyolefin is generally used because of its excellent adhesion to the substrate (for example, see Patent Documents 1 and 2). .

The modified polyolefin resin mainly composed of polypropylene resin is inferior in adhesion to a polyethylene base material among polyolefin base materials, and an improvement is desired. As an improvement in adhesion to a polyethylene substrate, for example, a composition using an ethylene copolymer and a polyolefin resin in combination has been proposed (see, for example, Patent Document 3).

JP 2001-279048 A JP 2002-187922 A JP 2012-1117068 A

The composition described in Patent Document 3 has improved adhesion to a polyethylene substrate. However, the use of the composition described in Patent Document 3 is limited as a heat seal composition, and there is a problem in solution stability and the like for use as a paint or primer.

An object of the present invention is to provide a modified polyolefin resin having excellent solution stability and good adhesion to a polyolefin substrate including a metal such as aluminum or a polyethylene substrate.

　（前記一般式（Ｉ）中、Ｒ^１は、水素原子又はメチル基を示し、Ｒ^２は、Ｃ_ｎＨ_２ｎ＋１で表される炭化水素基を示す。但し、ｎは、８～１８の整数である。）
〔３〕前記成分（Ａ）において、前記共重合体ａと前記共重合体ｂの含有率の比（共重合体ａ：共重合体ｂ）が、７０～９５：５～３０（但し、共重合体ａ＋共重合体ｂ＝１００質量％とする）である上記〔１〕又は〔２〕に記載の変性ポリオレフィン樹脂。
〔４〕前記共重合体ａのエチレン構造単位含有率が、１～２０ｍｏｌ％である上記〔１〕～〔３〕のいずれかに記載の変性ポリオレフィン樹脂。
〔５〕前記共重合体ｂの融点が、５０～１５０℃である上記〔１〕～〔４〕のいずれかに記載の変性ポリオレフィン樹脂。
〔６〕前記共重合体ｂの重量平均分子量が、１，０００～２００，０００である上記〔１〕～〔５〕のいずれかに記載の変性ポリオレフィン樹脂。
〔７〕重量平均分子量が、３０，０００～３００，０００である上記〔１〕～〔６〕のいずれかに記載の変性ポリオレフィン樹脂。
〔８〕上記〔１〕～〔７〕のいずれかに記載の変性ポリオレフィン樹脂を含む組成物。
〔９〕溶液、硬化剤及び接着成分からなる群より選択される少なくとも１種の成分をさらに含む上記〔８〕に記載の組成物。
〔１０〕上記〔１〕～〔７〕のいずれかに記載の変性ポリオレフィン樹脂又は上記〔８〕若しくは〔９〕に記載の組成物を含むプライマー。
〔１１〕上記〔１〕～〔７〕のいずれかに記載の変性ポリオレフィン樹脂又は上記〔８〕若しくは〔９〕に記載の組成物を含む塗料用バインダー。
〔１２〕上記〔１〕～〔７〕のいずれかに記載の変性ポリオレフィン樹脂又は上記〔８〕若しくは〔９〕に記載の組成物を含むインキ用バインダー。
〔１３〕上記〔１〕～〔７〕のいずれかに記載の変性ポリオレフィン樹脂又は上記〔８〕若しくは〔９〕に記載の組成物を含む層、金属層及び樹脂層を有する積層体。 As a result of intensive studies on the above problems, the present inventors have found that a copolymer a having an ethylene structural unit content of 50 mol% or more, a copolymer b having an ethylene structural unit content of less than 50 mol%, The present inventors have found that the above-mentioned problems can be solved by modifying a polyolefin resin containing at least the above-mentioned compounds, and have completed the present invention.
That is, the present inventors provide the following [1] to [13].
[1] Component (A): a polyolefin resin containing at least a copolymer a having an ethylene structural unit content of less than 50 mol% and a copolymer b having an ethylene structural unit content of 50 mol% or more. (B): A modified polyolefin resin which is a graft modified product modified with an α, β-unsaturated carboxylic acid or a derivative thereof.
[2] The modified polyolefin resin according to the above [1], wherein the graft modified product is a modified product further modified with a component (C): (meth) acrylic acid ester represented by the following general formula (I).

(In the general formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a hydrocarbon group represented by C _n H _{2n + 1} , where n is an integer of 8 to 18) is there.)
[3] In the component (A), the content ratio of the copolymer a and the copolymer b (copolymer a: copolymer b) is 70 to 95: 5 to 30 (provided that The modified polyolefin resin according to the above [1] or [2], which is (polymer a + copolymer b = 100 mass%).
[4] The modified polyolefin resin according to any one of [1] to [3], wherein the copolymer a has an ethylene structural unit content of 1 to 20 mol%.
[5] The modified polyolefin resin according to any one of the above [1] to [4], wherein the copolymer b has a melting point of 50 to 150 ° C.
[6] The modified polyolefin resin according to any one of [1] to [5], wherein the copolymer b has a weight average molecular weight of 1,000 to 200,000.
[7] The modified polyolefin resin according to any one of the above [1] to [6], which has a weight average molecular weight of 30,000 to 300,000.
[8] A composition comprising the modified polyolefin resin according to any one of [1] to [7].
[9] The composition according to [8], further including at least one component selected from the group consisting of a solution, a curing agent, and an adhesive component.
[10] A primer comprising the modified polyolefin resin according to any one of [1] to [7] or the composition according to [8] or [9].
[11] A coating binder containing the modified polyolefin resin according to any one of [1] to [7] or the composition according to [8] or [9].
[12] An ink binder comprising the modified polyolefin resin according to any one of [1] to [7] or the composition according to [8] or [9].
[13] A laminate having a modified polyolefin resin according to any one of [1] to [7] or a layer containing the composition according to [8] or [9], a metal layer, and a resin layer.

According to the present invention, it is possible to provide a modified polyolefin resin having excellent solution stability and good adhesion to a polyolefin substrate including a metal such as aluminum or a polyethylene substrate.

Hereinafter, the present invention will be described in detail with reference to preferred embodiments thereof.
In this specification, “(meth) acrylic acid” refers to methacrylic acid and / or acrylic acid.

[1. Modified polyolefin resin]
The modified polyolefin resin of the present invention is a graft modified product obtained by modifying a predetermined polyolefin resin with an α, β-unsaturated carboxylic acid or a derivative thereof, and a modified product further modified with a predetermined (meth) acrylic acid ester. It is preferable.
When the modified polyolefin resin is used for applications such as primer, paint, ink, etc., it is required to apply uniformly to eliminate coating unevenness. Therefore, the modified polyolefin resin is required to have a solution stability such that it is uniformly dissolved in a solvent and the resin does not precipitate over time, in addition to the property of adhering to the substrate.
Since the modified polyolefin resin of the present invention is a graft-modified product obtained by modifying a predetermined polyolefin resin described later, it adheres to a nonpolar substrate such as a polyethylene substrate and has excellent solution stability. It has been found out that it can be used for applications.

[1-1. Polyolefin resin]
The polyolefin resin contains at least a copolymer a having an ethylene structural unit content of less than 50 mol% and a copolymer b having an ethylene structural unit content of 50 mol% or more.

(Copolymer a)
Copolymer a is a copolymer having an ethylene structural unit content of less than 50 mol%. Since the copolymer a having an upper limit of ethylene structural unit content of less than 50 mol% is used, a modified polyolefin resin excellent in solution stability can be obtained by imparting polarity by a modification treatment described later.

Examples of the copolymer a include a copolymer obtained by copolymerizing an olefin or the like using a Ziegler-Natta catalyst or a metallocene catalyst as a polymerization catalyst.
Examples of the olefin include ethylene, propylene, 1-butene, 2-methyl-1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, Α-olefins such as 1-decene and 1-octadecene; 2-butene; isobutylene; conjugated dienes such as butadiene, isoprene and cyclopentadiene; vinylcyclohexane; β-pinene. Among these, ethylene or α-olefin is preferable, and ethylene or α-olefin having 3 to 6 carbon atoms (ethylene, propylene, 1-butene, 1-pentene, 1-hexene) is more preferable.

More specifically, examples of the copolymer a include a copolymer of ethylene and propylene, and a copolymer of ethylene and one or more other olefins. Among these, a copolymer of ethylene and propylene, and a copolymer of ethylene and an α-olefin having 3 to 6 carbon atoms are preferable, an ethylene-propylene copolymer, an ethylene-propylene-1-butene copolymer. Is more preferable.
The copolymer a may be a random copolymer or a block copolymer. Further, the copolymer a may be a single type or a combination of two or more types.

The upper limit of the ethylene structural unit content of the copolymer a is less than 50 mol%, preferably 30 mol% or less, and more preferably 20 mol% or less. When the upper limit value of the ethylene structural unit content of the copolymer a is less than 50 mol%, a modified polyolefin resin excellent in solution stability can be obtained by imparting polarity by a modification treatment described later. On the other hand, the lower limit is usually 1 mol% or more. When the lower limit value of the ethylene structural unit content of the copolymer a is 1 mol% or more, the crystallinity of the copolymer a is lowered, so that the adhesion to a substrate at low temperatures and the solution stability are further improved. obtain.
The ethylene structural unit content of the copolymer a is 1 to less than 50 mol%, preferably 1 to 30 mol%, more preferably 1 to 20 mol%.

The content of each structural unit such as an ethylene structural unit of the copolymer a can be calculated from the amount of the monomer used for the preparation of the copolymer a and the analysis result of the copolymer a using an instrument such as NMR. Moreover, in the case of a commercial item, you may judge based on product information.

40 degreeC or more is preferable and, as for the lower limit of melting | fusing point of the copolymer a, 50 degreeC or more is more preferable. When the melting point of the copolymer a is 40 ° C. or more, when the modified polyolefin resin is used for applications such as inks and paints, sufficient coating strength can be exhibited and the adhesion to the substrate is sufficiently exhibited. Can be done. Further, when used as an ink, blocking during printing can be suppressed. Moreover, the upper limit is preferably 90 ° C. or less, and more preferably 70 ° C. or less. When the melting point of the copolymer a is 90 ° C. or lower, when the modified polyolefin resin is used for applications such as ink and paint, the coating film is suppressed from becoming too hard, and the coating film can exhibit appropriate flexibility. . In addition, solution stability is improved.
The melting point of the copolymer a is preferably 40 to 90 ° C, more preferably 50 to 70 ° C.
The melting point was measured by using a DSC measuring device (Seiko Denshi Kogyo Co., Ltd.), and about 5 mg of sample was melted at 200 ° C. for 10 minutes, and then cooled to −50 ° C. at a rate of 10 ° C./min for crystallization. Later, it can be obtained as the melting peak temperature when it is further heated to 200 ° C. and melted at 10 ° C./min.

The lower limit of the weight average molecular weight of the copolymer a is preferably 30,000 or more, and more preferably 50,000 or more. When the weight average molecular weight is 30,000 or more, the resin has a cohesive force and can exhibit adhesion to a substrate. Moreover, the upper limit is preferably 300,000 or less, and more preferably 250,000 or less. When the weight average molecular weight is 300,000 or less, it has compatibility with other resins and solubility in solvents, and can be applied to paints and inks.
The weight average molecular weight of the copolymer a is preferably 30,000 to 300,000, more preferably 50,000 to 250,000.
The weight average molecular weight can be obtained from a standard polystyrene calibration curve by gel permeation chromatography (GPC).

(Copolymer b)
The copolymer b is a copolymer having an ethylene structural unit content of 50 mol% or more. Since the copolymer b having a lower limit of ethylene structural unit content of 50 mol% or more is used, a modified polyolefin resin having good adhesion to a polyolefin substrate, particularly a polyethylene substrate, can be obtained.

Examples of the copolymer b include a copolymer obtained by copolymerizing an olefin or the like using a Ziegler-Natta catalyst or a metallocene catalyst as a polymerization catalyst.
Examples of the olefin include ethylene, propylene, 1-butene, 2-methyl-1-butene, 3-methyl-1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-octene, Α-olefins such as 1-decene and 1-octadecene; 2-butene; isobutylene; conjugated dienes such as butadiene, isoprene and cyclopentadiene; vinylcyclohexane; β-pinene. Among these, ethylene and α-olefin are preferable, and ethylene and α-olefin having 3 to 6 carbon atoms (propylene, 1-butene, 1-pentene, 1-hexene) are more preferable.

More specifically, examples of the copolymer b include a copolymer of ethylene and propylene, and a copolymer of ethylene and one or more other olefins. Among these, a copolymer of ethylene and propylene, and a copolymer of ethylene and an α-olefin having 3 to 6 carbon atoms are preferable. An ethylene-propylene copolymer and an ethylene-1-butene copolymer are preferable. Is more preferable.
The copolymer b may be a random copolymer or a block copolymer. Further, the copolymer b may be a single type or a combination of two or more types.

The lower limit of the ethylene structural unit content of the copolymer b is 50 mol% or more, and preferably 60 mol% or more. When the lower limit of the ethylene structural unit content of the copolymer b is 50 mol% or more, a modified polyolefin resin having good adhesion to a polyolefin substrate, particularly a polyethylene substrate, can be obtained. On the other hand, the upper limit is usually 90 mol% or less. When the upper limit value of the ethylene structural unit content of the copolymer b is 90 mol% or less, a modified polyolefin resin having excellent solution stability can be obtained.
The ethylene structural unit content of the copolymer b is 50 mol% or more, preferably 60 to 90 mol%.

The content of each structural unit such as an ethylene structural unit of the copolymer b can be calculated from the amount of the monomer used for the preparation of the copolymer b and the analysis result of the copolymer b using an instrument such as NMR. Moreover, in the case of a commercial item, you may judge based on product information.

The lower limit of the melting point of the copolymer b is preferably 20 ° C. or higher, more preferably 30 ° C. or higher, and further preferably 50 ° C. or higher. When the melting point of the copolymer b is 20 ° C. or more, when the modified polyolefin resin is used for applications such as inks and paints, sufficient coating strength can be exhibited and the adhesion to the substrate is sufficiently exhibited. Can be done. Further, when used as an ink, blocking during printing can be suppressed. The upper limit is preferably 150 ° C. or lower, more preferably 100 ° C. or lower, and further preferably 95 ° C. or lower. When the melting point of the copolymer b is 150 ° C. or less, when the modified polyolefin resin is used for applications such as ink and paint, the coating film is prevented from becoming excessively hard and the coating film exhibits appropriate flexibility. obtain. Moreover, solution stability improves.
The melting point of the copolymer b is preferably 20 to 150 ° C, more preferably 30 to 150 ° C, further preferably 35 to 150 ° C, still more preferably 50 to 100 ° C, and particularly preferably 50 to 95 ° C.
The melting point was measured by using a DSC measuring device (Seiko Denshi Kogyo Co., Ltd.), and about 5 mg of sample was melted at 200 ° C. for 10 minutes, and then cooled to −50 ° C. at a rate of 10 ° C./min for crystallization. Later, it can be obtained as the melting peak temperature when it is further heated to 200 ° C. and melted at 10 ° C./min.

The lower limit of the weight average molecular weight of the copolymer b is preferably 1,000 or more, and more preferably 2,500 or more. When the weight average molecular weight is 1,000 or more, the resin has a cohesive force and can exhibit adhesion to a substrate. Moreover, the upper limit is preferably 200,000 or less, and more preferably 150,000 or less. When the weight average molecular weight is 200,000 or less, it has compatibility with other resins and solubility in solvents, and can be applied to paints and inks.
The weight average molecular weight of the copolymer b is preferably 1,000 to 200,000, more preferably 2,500 to 150,000.
The weight average molecular weight can be obtained from a standard polystyrene calibration curve by gel permeation chromatography (GPC).

(Ratio of content)
The content ratio of copolymer a to copolymer b (copolymer a: copolymer b) is preferably 70 to 95: 5 to 30, and more preferably 80 to 90:10 to 20. However, copolymer a + copolymer b = 100 mass%. When the content ratio is 70 to 95: 5 to 30, there is an effect that the adhesion to the polyethylene resin is excellent and the solution stability is excellent.

[1-2. Graft modified product]
The graft modified product is a modified product obtained by modifying the polyolefin resin described in “1-1. Polyolefin resin” with an α, β-unsaturated carboxylic acid or a derivative thereof, and further modified with a predetermined (meth) acrylic ester. The modified product is preferably used.
The graft modified product can be a modified polyolefin resin that adheres to a nonpolar substrate such as a polyethylene substrate and is excellent in solution stability.

(Α, β-unsaturated carboxylic acid or derivative thereof)
Examples of the α, β-unsaturated carboxylic acid or derivatives thereof include maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, mesaconic acid, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, Examples include hymic anhydride and (meth) acrylic acid. Of these, maleic anhydride is preferred.
The α, β-unsaturated carboxylic acid or derivative thereof may be one or more compounds selected from α, β-unsaturated carboxylic acid and derivatives thereof, and one or more α, β-unsaturated carboxylic acid may be used. And combinations of one or more derivatives thereof, combinations of two or more α, β-unsaturated carboxylic acids, and combinations of two or more derivatives of α, β-unsaturated carboxylic acids.

The introduction amount (graft weight) of the α, β-unsaturated carboxylic acid or derivative thereof is preferably 0.1 to 10% by weight, and 0.5 to 4% by weight when the modified polyolefin resin is 100% by weight. More preferred. When the graft weight is 0.1% by weight or more, the adhesion of the resulting modified polyolefin resin to a material such as a metal adherend can be maintained. When the graft weight is 10% by weight or less, generation of unreacted grafts can be prevented, and sufficient adhesion to the resin adherend can be obtained.
The introduction amount (graft weight) of the α, β-unsaturated carboxylic acid or derivative thereof can be measured by an alkali titration method.

((Meth) acrylic acid ester)
(Meth) acrylic acid ester is a compound represented by general formula (I). When the compound is used for modification, the molecular weight distribution of the modified polyolefin resin can be narrowed, and the low-temperature stability of the solution, compatibility with other resins, and adhesiveness can be improved. The (meth) acrylic acid ester represented by the general formula (I) may be used alone, or a plurality of them may be mixed and used in an arbitrary ratio.

In general formula (I), R ¹ represents H or CH ₃ , preferably CH ₃ . R ² represents C _n H _{2n + 1} . n represents an integer of 8 to 18, preferably 8 to 15, more preferably 8 to 14, and still more preferably 8 to 13. As the compound represented by the formula (I), lauryl (meth) acrylate and octyl (meth) acrylate are preferable, and lauryl methacrylate and octyl methacrylate are more preferable.

The introduction amount (graft weight) of the (meth) acrylic acid ester is preferably 0.1 to 10% by weight, more preferably 0.4 to 4% by weight when the modified polyolefin resin is taken as 100% by weight. When the graft weight is 0.1% by weight or more, the molecular weight distribution of the modified polyolefin resin can be kept in a sufficiently narrow range. That is, the adverse effect of the high molecular weight portion can be prevented, and the solvent solubility, the low temperature stability of the solution, and the compatibility with other resins can be maintained well. Moreover, the bad influence of a low molecular weight part can be prevented and adhesive force can be improved. When the graft weight is 10% by weight or less, the generation of unreacted grafts can be prevented, and the adhesion to the resin adherend can be maintained well.
The introduction amount (graft weight) of (meth) acrylic acid ester can be obtained by ¹ H-NMR.

(Other modifiers)
As long as the effects of the present invention are not impaired, the graft-modified product can be used in combination with other modifying agents other than α, β-unsaturated carboxylic acid or a derivative thereof and (meth) acrylic acid ester. Examples of other modifiers that can be used include (meth) acrylic acid derivatives (for example, N-methyl (meth) acrylamide, hydroxyethyl (meth) acrylamide, (meth) acryloylmorpholine).
Other modifiers other than α, β-unsaturated carboxylic acid or its derivative and (meth) acrylic acid ester in the modified polyolefin resin may be used alone or in combination of two or more. Good. However, it is preferable that the total graft weight of the other modifiers does not exceed the total graft weight of the α, β-unsaturated carboxylic acid or its derivative and (meth) acrylic acid ester.

The method for modifying the polyolefin resin to obtain the modified polyolefin resin is not particularly limited, and may be performed by a known method. For example, a solution method in which a mixture of a polyolefin resin, an α, β-unsaturated carboxylic acid or derivative thereof, and a (meth) acrylic acid ester is dissolved in a solvent such as toluene and a radical generator is added, a Banbury mixer, Modified polyolefin resin by a melt kneading method or the like using a kneader, an extruder or the like to add and knead polyolefin resin, α, β-unsaturated carboxylic acid or derivative thereof, (meth) acrylic acid ester, and radical generator The method of obtaining is mentioned.
When α, β-unsaturated carboxylic acid or a derivative thereof and (meth) acrylic ester are used, these may be added all at once or sequentially.

The radical generator can be appropriately selected from known radical generators. Of these, organic peroxide compounds are preferred. For example, di-t-butyl peroxide, dicumyl peroxide, t-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, 1,1-bis (t -Butylperoxy) -3,5,5-trimethylcyclohexane, 1,1-bis (t-butylperoxy) -cyclohexane, cyclohexanone peroxide, t-butylperoxybenzoate, t-butylperoxyisobutyrate, Examples thereof include t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, and cumylperoxyoctoate. Of these, dicumyl peroxide, di-t-butyl peroxide, and dilauryl peroxide are preferable.

The addition amount of the radical generator in the graft polymerization reaction is 1 to 100% by weight with respect to the total amount (weight) of the addition amount of α, β-unsaturated carboxylic acid or its derivative and the addition amount of (meth) acrylic acid ester. Preferably, 10 to 50% by weight is more preferable. By being 1% by weight or more, sufficient graft efficiency can be maintained. By being 100 weight% or less, the fall of the weight average molecular weight of modified polyolefin resin can be prevented.

[1-3. Physical properties]
The lower limit value of the weight average molecular weight of the modified polyolefin resin is preferably 30,000 or more, more preferably 50,000 or more, further preferably 80,000 or more, still more preferably 100,000 or more, particularly more than 150,000. preferable. When it is 30,000 or more, there is a cohesive force of the resin, and adhesion to the substrate can be expressed. Moreover, the upper limit is preferably 300,000 or less, more preferably 250,000 or less, and even more preferably 200,000 or less. If it is 300,000 or less, it has compatibility with other resins and solubility in solvents, and can be applied to paints and inks.
The weight average molecular weight of the modified polyolefin resin is preferably 30,000 to 300,000, more preferably 50,000 to 250,000, further preferably 80,000 to 200,000, and more preferably 100,000 to 200,000. More preferably, it is more preferably more than 150,000 to 200,000 or less.
The weight average molecular weight can be obtained from a standard polystyrene calibration curve by gel permeation chromatography (GPC).

[1-4. Application]
The modified polyolefin resin of the present invention has low adhesion (adhesiveness) and is also useful as an intermediate medium for substrates that are difficult to apply, such as paints. For example, polypropylene having poor adhesion (adhesiveness), It can be used as an adhesive between polyolefin-based substrates such as polyethylene. In this case, it can be used regardless of whether the substrate is surface-treated with plasma, corona or the like. Further, the adhesion stability of the paint can be improved by laminating the modified polyolefin resin of the present invention on the surface of the polyolefin base material by a hot melt system and further coating the paint on the polyolefin resin.
In addition, the modified polyolefin resin of the present invention can also exhibit excellent adhesion between a metal and a resin. Examples of the metal include aluminum, aluminum alloy, nickel, and stainless steel. Examples of the resin include nonpolar resins such as polyethylene, polyurethane resins, polyamide resins, acrylic resins, and polyester resins.
Therefore, the modified polyolefin resin of the present invention can be used as an adhesive, a primer, a paint binder and an ink binder or as these components.

[2. Composition]
The composition of this invention contains said modified polyolefin resin. The composition preferably further includes at least one component selected from the group consisting of a solution, a curing agent, and an adhesive component as another component.

(solution)
One embodiment of the composition of the present invention is a resin composition comprising the modified polyolefin resin and a solution. An organic solvent is mentioned as a solution. Examples of organic solvents include aromatic solvents such as toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone, methyl butyl ketone and ethyl cyclohexane; fats such as cyclohexane, methyl cyclohexane, nonane and decane And aliphatic or alicyclic hydrocarbon solvents. These organic solvents may be used individually by 1 type, and may be contained in the resin composition as 2 or more types of mixed solvents. From the viewpoint of environmental problems, it is preferable to use a solvent other than the aromatic solvent as the organic solvent, and it is more preferable to use a mixed solvent of an alicyclic hydrocarbon solvent and an ester solvent or a ketone solvent.

In addition, in order to increase the storage stability of a solution of a resin composition containing a modified polyolefin resin and a solution, alcohol (eg, methanol, ethanol, propanol, isopropyl alcohol, butanol), propylene glycol ether (eg, propylene glycol methyl ether) , Propylene glycol ethyl ether, propylene glycol-t-butyl ether) may be used singly or in combination of two or more. In this case, it is preferable to add 1 to 20% by mass relative to the organic solvent.

(Curing agent)
Another embodiment of the composition of the present invention is a composition comprising the modified polyolefin resin and a curing agent. Examples of the curing agent include a polyisocyanate compound, an epoxy compound, a polyamine compound, a polyol compound, or a crosslinking agent whose functional group is blocked with a protective group. One type of curing agent may be used, or a combination of a plurality of types may be used.

The blending amount of the curing agent can be appropriately selected depending on the content of the modified polyolefin resin of the present invention. Moreover, when mix | blending a hardening | curing agent, catalysts, such as an organotin compound and a tertiary amine compound, can be used together according to the objective.

(Adhesive component)
Yet another embodiment of the composition of the present invention is a composition comprising the modified polyolefin resin and an adhesive component. As the adhesive component, known adhesive components such as a polyester-based adhesive, a polyurethane-based adhesive, and an acrylic-based adhesive can be used as long as the desired effects are not impaired.

Since the composition of the present invention is excellent in adhesion between nonpolar resins such as polyolefin-based substrates or between nonpolar resins and metals, it can be used as an adhesive, a primer, a binder for paints, and a binder for ink. It is useful as an adhesive in a laminate film such as a laminate film.

[3. Primer, binder]
The primer, paint binder or ink binder of the present invention comprises the modified polyolefin resin or the composition described above. Therefore, it is excellent in adhesiveness, solution stability, and heat resistance, and should be suitably used as a primer for top coating on polyolefin substrates such as automobile bumpers, and a binder for coatings that have excellent adhesion to top coating and clear. Can do.

Primers, paint binders, or ink binders of the present invention can be used in the form of a solution, powder, sheet, or the like depending on the application. At that time, additives such as antioxidants, light stabilizers, ultraviolet absorbers, pigments, dyes, inorganic fillers and the like can be blended as necessary.

[4. Laminate]
The laminated body of this invention has a layer containing said modified polyolefin resin or said composition, a metal layer, and a resin layer. The arrangement of the layers in the laminate is not particularly limited, but the mode in which the metal layer and the resin layer are positioned with the layer containing the modified polyolefin resin or composition interposed therebetween, the first resin layer and the second resin layer with the metal layer interposed therebetween And a layer containing a modified polyolefin resin or a composition is sandwiched between the metal layer and each resin layer. The laminate of the present invention may be used as a pouch for refilling toiletries.

Hereinafter, the present invention will be described in detail with reference to examples. The following examples are for explaining the present invention preferably and are not intended to limit the present invention. In addition, unless otherwise indicated, the measuring methods, such as a physical-property value, are the measuring methods described below. “Parts” indicates parts by mass.

[Weight average molecular weight]
It is a value measured under the following conditions.
Measuring instrument: HLC-8320GPC (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Column: TSKgel (manufactured by Tosoh Corporation)

[Structural unit content (mol%)]
The structural unit content of each monomer was determined from the monomer composition ratio used in the polymerization. When the composition ratio of the monomer used for the polymerization was unknown, it was measured using a nuclear magnetic resonance apparatus (NMR) as shown below.
About 60 mg of a sample was dissolved in tetrachloroethane (d2), a ¹³ C-NMR spectrum was measured under the following conditions, and the structural unit content was calculated from the integrated value of the chain methylene carbon signal.
Observation range: 250 ppm
Measurement mode: Single pulse proton decoupling Pulse angle: 5.25 μsec (45 °)
Repeat time: 5.5 seconds Measurement temperature: 120 ° C

[(Meth) acrylic ester graft weight (% by weight)]
^It was measured by ¹ H-NMR.

[Graft weight (% by weight) of α, β-unsaturated carboxylic acid or derivative thereof]
It measured by the alkali titration method.

[Melting point (° C)]
In accordance with JIS K7121-1987, using a DSC measuring apparatus (manufactured by Seiko Denshi Kogyo), about 5 mg of sample was kept in a heated and melted state at 200 ° C. for 10 minutes, and then cooled at a rate of 10 ° C./min to −50 Stable holding at ℃. Thereafter, the melting peak temperature at the time of melting at 200 ° C. was further measured at 10 ° C./min, and the temperature was evaluated as Tm.

[Melt flow rate (130 ° C / 10 min)]
Based on ASTM D1238, calculation was performed with a melt flow index tester (manufactured by Yasuda Seiki Seisakusho) under the conditions of a measurement temperature of 130 ° C. and a measurement load of 2.16 kg.

[Viscosity (mPa · s)]
In a glass bottle, the modified polyolefin resins obtained in Examples and Comparative Examples were dissolved in a methylcyclohexane / methyl ethyl ketone solution (mixing ratio 80/20) to prepare a modified polyolefin resin coating composition having a concentration of 15% by mass. . The obtained solution was adjusted to 25 ° C. in a thermostatic bath, and measured using a B-type viscometer (BMII viscometer, manufactured by Toki Sangyo Co., Ltd.) under the condition of a rotational speed of 60 rpm.

[Evaluation of appearance]
The solution sample was placed in a sealed glass bottle and stored at 5 ° C. for 7 days, and then the appearance was evaluated visually.
A: The fluidity of the composition solution is maintained.
B: Although the fluidity of the composition solution is slightly lowered, there is no practical problem.
C: The fluidity of the composition solution is reduced.

[Heat seal strength test (g / 15 min)]
In the heat seal strength test, the solution sample was applied as an adhesive with a # 16 Meyer bar so that the resin dry film thickness was 3 μm on the aluminum foil, and dried at 180 ° C. for 10 seconds. The coated aluminum foil is each of linear low density polyethylene (hereinafter referred to as “LLDPE”), low density polyethylene (hereinafter referred to as “LDPE”), or high density polyethylene (hereinafter referred to as “HDPE”). A test piece cut out to a width of 15 mm was prepared by laminating with a film and thermocompression bonding under conditions of 200 kPa at 90 ° C. for 10 seconds. After the test piece was stored at 23 ° C. and 50% relative humidity for 24 hours at constant temperature and humidity, the laminate adhesive strength was measured under the conditions of 180-degree direction peeling and peeling speed of 100 mm / min.

Copolymer a- (1), copolymer a- (2), copolymer b- (1), copolymer b- () used in Examples 1 to 3 and Comparative Examples 1 to 3 below. 2) Physical property values of copolymer b- (3) and polymer b- (4) are shown in Table 1 below.

(Example 1: Production of modified polyolefin resin (Example-1))
In a four-necked flask equipped with a stirrer, a condenser, and a dropping funnel, copolymer a- (1) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000) , Tm = 65 ° C.)) 90 parts) and copolymer b- (1) (ethylene-1-butene copolymer (ethylene component 90 mol%, 1-butene component 10 mol%, weight average molecular weight 2,700, Tm = 91) ° C)) 10 parts in 400 g of toluene was heated and dissolved, and then the temperature in the system was kept at 110 ° C while stirring, while 4.0 parts of maleic anhydride, 3.0 parts of lauryl methacrylate, di-t- 1.5 parts of butyl peroxide was added dropwise over 3 hours, and the mixture was further reacted for 1 hour.
After completion of the reaction, the reaction mixture was cooled to room temperature and purified by putting the reaction product into a large excess of acetone. The MFR was 9.0 g / 10 min (130 ° C.), the weight average molecular weight was 190,000, maleic anhydride A modified polyolefin resin (Execution-1) having a graft weight of 2.6% by weight and a lauryl methacrylate graft weight of 2.0% by weight was obtained.

(Example 2: Production of modified polyolefin resin (Example-2))
In a four-necked flask equipped with a stirrer, a condenser, and a dropping funnel, copolymer a- (1) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000) , Tm = 65 ° C.)) and 90 parts of copolymer b- (2) (ethylene component 90 mol%, propylene component 10 mol%, weight average molecular weight 100,000, Tm = 58 ° C.)) 10 parts in toluene 400 g After dissolution, while stirring while maintaining the temperature in the system at 110 ° C., 4.0 parts of maleic anhydride, 3.0 parts of lauryl methacrylate, and 1 part of di-t-butyl peroxide were respectively added over 3 hours. The solution was added dropwise and allowed to react for an additional hour.
After completion of the reaction, the reaction mixture was cooled to room temperature and purified by putting the reaction product into a large excess of acetone. The MFR was 5.0 g / 10 min (130 ° C.), the weight average molecular weight was 180,000, maleic anhydride A modified polyolefin resin (Example-2) having a graft weight of 2.6% by weight and a lauryl methacrylate graft weight of 1.9% by weight was obtained.

(Example 3: Production of modified polyolefin resin (Example-3))
90 parts of copolymer a- (1) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000, Tm = 65 ° C.)) and copolymer b- (3) (Ethylene-1-butene copolymer (ethylene component 70 mol%, 1-butene component 30 mol%, weight average molecular weight 150,000, Tm = 55 ° C.)) 10 parts, maleic anhydride 1.0 part, lauryl methacrylate The reaction was carried out by kneading 0 part and 0.5 part of di-t-butyl peroxide using a twin screw extruder set at 170 ° C. Vacuum degassing is performed in the extruder to remove the remaining unreacted material, the MFR is 5.0 g / 10 min (130 ° C.), the weight average molecular weight is 180,000, and the graft weight of maleic anhydride is 0.5 wt. %, And a modified polyolefin resin (Execution-3) having a graft weight of 0.4% by weight of lauryl methacrylate was obtained.

(Example 4: Production of modified polyolefin resin (Example 4))
90 parts of copolymer a- (1) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000, Tm = 65 ° C.)) and copolymer b- (3) (Ethylene-1-butene copolymer (ethylene component 70 mol%, 1-butene component 30 mol%, weight average molecular weight 150,000, Tm = 55 ° C.)) 10 parts, maleic anhydride 1.0 part, lauryl methacrylate The reaction was carried out by kneading 0 part and 0.5 part of di-t-butyl peroxide using a twin screw extruder set at 200 ° C. Vacuum degassing is performed in the extruder to remove the remaining unreacted material, the MFR is 20.0 g / 10 min (130 ° C.), the weight average molecular weight is 100,000, and the maleic anhydride graft weight is 0.5 weight. %, A modified polyolefin resin (Execution-4) having a graft weight of 0.4% by weight of lauryl methacrylate was obtained.

(Comparative Example 1: Production of modified polyolefin resin (Comparative-1))
The component (A) is only copolymer a- (2) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 50,000, Tm = 70 ° C.)). The modification was performed in the same manner as in Example 1.
The resulting modified polyolefin resin (Comparative-1) had an MFR of 250 g / 10 min (130 ° C.), a weight average molecular weight of 70,000, a maleic anhydride graft weight of 3.5% by weight, and a lauryl methacrylate graft weight. It was 2.0% by weight.

(Comparative Example 2: Production of modified polyolefin resin (Comparative-2))
Except for the use of only copolymer a- (1) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000, Tm = 65 ° C.)) as component (A). The modification was performed in the same manner as in Example 2.
The resulting modified polyolefin resin (Comparative-2) has an MFR of 20 g / 10 min (130 ° C.), a weight average molecular weight of 130,000, a maleic anhydride graft weight of 3.1% by weight, and a lauryl methacrylate graft weight. It was 1.9% by weight.

(Comparative Example 3: Production of modified polyolefin resin (Comparative-3))
90 parts of copolymer a- (2) (propylene-ethylene copolymer (propylene component 88 mol%, ethylene component 12 mol%, weight average molecular weight 200,000, Tm = 65 ° C.)) and polymer b- (4) ( Modification was performed in the same manner as in Example 1 except that 10 parts of an ethylene homopolymer (weight average molecular weight 1,000, Tm = 119 ° C.) was used.
The resulting modified polyolefin resin (Comparative-3) had an MFR of 10 g / 10 min (130 ° C.), a weight average molecular weight of 150,000, a maleic anhydride graft weight of 2.6 wt%, and a lauryl methacrylate graft weight. It was 2.0% by weight.

Table 2 shows a list of physical property values of the modified polyolefin resins prepared in Examples 1 to 4 and Comparative Examples 1 to 3.

Table 3 shows the heat seal strength test results of the modified polyolefin resin aluminum foils prepared in Examples 1 to 4 and Comparative Examples 1 to 3 and various polyethylene films and the low-temperature storage stability test results of the solutions.

As is apparent from Table 3, the modified polyolefin resin provided by the present invention is excellent in adhesiveness between the aluminum foil and various polyethylene films, and at the same time has low-temperature storage stability of the solution (Examples 1 to 4).
On the other hand, the conventional modified polyolefin resin has insufficient adhesion between the aluminum foil and various polyethylene films (Comparative-1 and Comparative-2). In addition, when polyethylene itself was used instead of the ethylene high content copolymer b, the low-temperature storage stability of the solution was inferior even if the adhesiveness between the aluminum foil and various polyethylene films was sufficient (Comparative-3). ).

Claims (13)

Component (A): A polyolefin resin containing at least a copolymer a having an ethylene structural unit content of less than 50 mol% and a copolymer b having an ethylene structural unit content of 50 mol% or more. Component (B) : Modified polyolefin resin which is a graft modified product modified with α, β-unsaturated carboxylic acid or its derivative. The modified polyolefin resin according to claim 1, wherein the graft modified product is a modified product further modified with a component (C): (meth) acrylic acid ester represented by the following general formula (I).

(In the general formula (I), R ¹ represents a hydrogen atom or a methyl group, and R ² represents a hydrocarbon group represented by C _n H _{2n + 1} , where n is an integer of 8 to 18) is there.) In the component (A), the content ratio of the copolymer a and the copolymer b (copolymer a: copolymer b) is 70 to 95: 5 to 30 (provided that the copolymer a + The modified polyolefin resin according to claim 1 or 2, wherein the copolymer b is 100 mass%). The modified polyolefin resin according to any one of claims 1 to 3, wherein the copolymer a has an ethylene structural unit content of 1 to 20 mol%. The modified polyolefin resin according to any one of claims 1 to 4, wherein the copolymer b has a melting point of 50 to 150 ° C. The modified polyolefin resin according to any one of claims 1 to 5, wherein the copolymer b has a weight average molecular weight of 1,000 to 200,000. The modified polyolefin resin according to any one of claims 1 to 6, wherein the weight average molecular weight is 30,000 to 300,000. A composition comprising the modified polyolefin resin according to any one of claims 1 to 7. The composition according to claim 8, further comprising at least one component selected from the group consisting of a solution, a curing agent, and an adhesive component. A primer comprising the modified polyolefin resin according to any one of claims 1 to 7 or the composition according to claim 8 or 9. A paint binder comprising the modified polyolefin resin according to any one of claims 1 to 7 or the composition according to claim 8 or 9. An ink binder comprising the modified polyolefin resin according to any one of claims 1 to 7 or the composition according to claim 8 or 9. A laminate comprising a layer comprising the modified polyolefin resin according to any one of claims 1 to 7 or the composition according to claim 8 or 9, a metal layer, and a resin layer.