JP7377804B2 - Modified polyolefin resin and its manufacturing method - Google Patents

Description

The present invention relates to a modified polyolefin resin and a method for producing the same.

Patent Document 1 describes a modified polyolefin resin in which the following (A-1) is graft-polymerized and/or the following (A-2) is chlorinated, and (B) is graft-polymerized. Polyolefin resins are described.
(A-1) One or more polarizing agents selected from unsaturated carboxylic acids, derivatives and anhydrides of unsaturated carboxylic acids, and (meth)acrylic esters represented by general formula (I).
_CH2 = _{CR1COOR2 ...} (I)
(In formula (I), R ₁ = H or CH ₃ , R ₂ = C _n H _2n+1 , n = an integer from 1 to 18)
(A-2) Chlorine (B) α-olefin unit containing 80 to 100 mol% of ethylene units and having 3 to 10 carbon atoms, with the proportion of the main chain end having an unsaturated bond at one end being 90% or more An ethylene α-olefin copolymer having 0 to 20 mol%.

Patent Document 1 describes that the modified polyolefin resin has excellent adhesion to a polyolefin base material made of polyolefin such as polypropylene or polyethylene, that is, a non-polar base material.

Patent No. 4848011

In order to apply the modified polyolefin resin of Patent Document 1 to a nonpolar substrate, a solution of the modified polyolefin resin may be prepared. However, the modified polyolefin resin of Patent Document 1 has a poor liquid state (for example, the solubility in a solvent is poor, and the solution is cloudy).

Therefore, an object of the present invention is to provide a modified polyolefin resin that has excellent adhesion to a nonpolar substrate and also has excellent solubility in a solvent when preparing a solution.

As a result of extensive studies, the present inventors have found that the above-mentioned problems can be solved by a modified polyolefin resin in which the polyolefin resin is modified with a specific modifying component, and the present invention has been completed.

That is, the present invention provides the following.
[1] A modified polyolefin resin in which the polyolefin resin (A) is modified with a modifying component, wherein the modifying component is one or more compounds selected from α,β-unsaturated carboxylic acids and acid anhydrides thereof ( B) and an amine compound (C) having a hydrocarbon group.
[2] The modified polyolefin resin according to [1], wherein the modified polyolefin resin contains an imide bond or an amide bond derived from the compound (B) and the amine compound (C).
[3] The modified polyolefin resin according to [1] or [2], wherein the hydrocarbon group of the amine compound (C) is an alkyl group or alkenyl group having 6 to 22 carbon atoms.
[4] The amine compound (C) is an amine compound (C1) represented by the following formula (1) or an amine compound (C2) represented by the following formula (2) [1] to [3] The modified polyolefin resin according to any one of the above.
H ₂ NR ¹¹ (1)
HNR ²¹ R ²² (2)
(In formula (1), R ¹¹ represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group, and in formula (2), R ²¹ and R ²² each independently represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group.)
[5] The above amine compound (C) is an amine compound represented by the above formula (1), and in the above formula (1), R ¹¹ is an alkyl group or an alkenyl group having 6 to 22 carbon atoms. , the modified polyolefin resin according to [4].
[6] The modified polyolefin resin according to any one of [1] to [5], wherein the polyolefin resin (A) is a polymer containing a structural unit derived from ethylene.
[7] The modified polyolefin resin according to any one of [1] to [6], wherein the modifying component further contains a radically polymerizable monomer.
[8] The modified polyolefin resin according to any one of [1] to [7], wherein the modified polyolefin resin is a chlorinated modified polyolefin resin.
[9] A heat sealing agent, adhesive, primer, or binder for paint or ink containing the modified polyolefin resin according to any one of [1] to [8].
[10] A modification step of modifying the polyolefin resin (A) with a modifying component to obtain a modified polyolefin resin, the modifying component being one or more selected from α,β-unsaturated carboxylic acids and acid anhydrides thereof. A method for producing a modified polyolefin resin, comprising a compound (B) and an amine compound (C) having a hydrocarbon group.
[11] In the modification step, the polyolefin resin (A) is graft-modified with the compound (B) to obtain an acid-modified polyolefin resin, and then the acid-modified polyolefin resin and the amine compound (C) are combined. The method for producing a modified polyolefin resin according to [10], which is a step of reacting to obtain the modified polyolefin resin.
[12] The method for producing a modified polyolefin resin according to [10] or [11], wherein the modified polyolefin resin contains an imide bond or an amide bond derived from the compound (B) and the amine compound (C).
[13] The modified polyolefin resin according to any one of [10] to [12], wherein the hydrocarbon group of the amine compound (C) is an alkyl group or alkenyl group having 6 to 22 carbon atoms. Production method.
[14] The amine compound (C) is an amine compound (C1) represented by the following formula (1) or an amine compound (C2) represented by the following formula (2), [10] to [13] A method for producing a modified polyolefin resin according to any one of the above.
H ₂ NR ¹¹ (1)
HNR ²¹ R ²² (2)
(In formula (1), R ¹¹ represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group, and in formula (2), R ²¹ and R ²² each independently represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group.)
[15] The above amine compound (C) is an amine compound represented by the above formula (1), and in the above formula (1), R ¹¹ is an alkyl group or an alkenyl group having 6 to 22 carbon atoms. , the method for producing a modified polyolefin resin according to [14].
[16] The method for producing a modified polyolefin resin according to any one of [10] to [15], wherein the polyolefin resin (A) is a polymer containing a structural unit derived from ethylene.
[17] Further, according to any one of [10] to [16], the method further includes a chlorination step of obtaining a chlorinated modified polyolefin resin by chlorinating the modified polyolefin resin obtained in the modification step with chlorine. The method for producing the modified polyolefin resin described above.

The modified polyolefin resin of the present invention can exhibit excellent adhesion to nonpolar substrates, and can also exhibit excellent solubility in solvents when preparing solutions.

<Modified polyolefin resin>
The modified polyolefin resin of the present invention is a modified resin in which the polyolefin resin (A) is modified with a modifying component. The modifying component includes a specific compound (B) and a specific amine compound (C). As a result, the modified polyolefin resin of the present invention can exhibit excellent adhesion to non-polar substrates, and can also exhibit good solubility in solvents when preparing solutions, so that solutions with excellent transparency can be obtained. is obtained.

Examples of the non-polar base material include a base material made of polyolefin resin (polyolefin base material). Polyolefin substrates are generally known as difficult-to-adhere substrates, and are often difficult to adhere to the same type of substrate or to different types of substrates, or to paint. Generally, polyethylene substrates have poorer adhesion and adhesive properties. The modified polyolefin resin of the present invention also has excellent adhesion to polyethylene substrates.

As the polyolefin resin (A), a polymer containing a structural unit derived from ethylene is suitable from the viewpoint of further improving the adhesion to the polyethylene base material. Examples of polymers containing structural units derived from ethylene include ethylene homopolymers and copolymers of ethylene and α-olefins having 3 to 10 carbon atoms. Examples of α-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1- Examples include pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 1-octene, 3-ethyl-1-hexene, 1-octene, and 1-decene. , propylene and 1-butene are preferred, and propylene is more preferred. The α-olefins may be used alone or in combination of two or more. In the above copolymer, it is preferable that the constituent units derived from α-olefin having 4 to 10 carbon atoms account for 20% by mass or less of the constituent units of the copolymer. As the copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms, a copolymer of ethylene and propylene, a copolymer of ethylene, propylene, and 1-butene are suitable. A copolymer of ethylene and an α-olefin having 3 to 10 carbon atoms contains 2 to 2 to 10% by weight of the structural units derived from ethylene and the α-olefin. It is preferably contained in an amount of 30% by weight, more preferably 5 to 25% by weight, even more preferably 7 to 20% by weight, even more preferably 8 to 15% by weight. The structural unit derived from an α-olefin is preferably contained in an amount of 70 to 98% by weight, more preferably 75 to 95% by weight, still more preferably 80 to 93% by weight, even more preferably 85 to 98% by weight. It is 92% by weight.

As the polyolefin resin (A), a propylene homopolymer or a copolymer of propylene and an α-olefin having 4 to 10 carbon atoms may be used. When these are used, a modified polyolefin resin having excellent adhesion to nonpolar substrates can be obtained. In the above copolymer, it is preferable that the constituent units derived from α-olefin having 4 to 10 carbon atoms account for 20% by mass or less of the constituent units of the copolymer. As the copolymer of propylene and an α-olefin having 4 to 10 carbon atoms, a copolymer of propylene and 1-butene is preferred.

The polyolefin resin (A) may be used alone or in combination of two or more. When the polyolefin resin (A) is a copolymer, it may be a random copolymer or a block copolymer. It is preferable that the polyolefin resin (A) does not contain a structural unit derived from an α-olefin having 4 or more carbon atoms.

The weight average molecular weight of the polyolefin resin (A) is not particularly limited. However, the weight average molecular weight of the modified polyolefin resin is preferably 15,000 to 300,000, more preferably 30,000 to 300,000, and even more preferably 100,000 to 300,000. It is preferably 200,000 to 300,000, particularly preferably 200,000 to 300,000. Therefore, if the weight average molecular weight of the polyolefin resin (A) is greater than 300,000, it may be degraded in the presence of heat or radicals so that the weight average molecular weight of the resulting modified polyolefin resin falls within the above range. preferable. In this specification, the weight average molecular weight is a value measured by gel permeation chromatography (standard substance: polystyrene). For example, GPC can be performed under the following conditions.
Measuring equipment: HLC-8320GPC (manufactured by Tosoh Corporation)
Eluent: Tetrahydrofuran Column: TSKgel (manufactured by Tosoh Corporation)

Compound (B) is one or more selected from α,β-unsaturated carboxylic acids and acid anhydrides thereof. Thus, the compound (B) may be used alone or in combination of two or more. Examples of the α,β-unsaturated carboxylic acid include fumaric acid, maleic acid, itaconic acid, mesaconic acid, citraconic acid, aconitic acid, and nadic acid. Examples of the acid anhydride include acid anhydrides having a cyclic structure (preferably a cyclic structure containing a -CO-O-CO- group), such as maleic anhydride, citraconic anhydride, itaconic anhydride, and anhydride. Aconitic acid is preferred, and maleic anhydride and itaconic anhydride are more preferred. Among these, maleic anhydride, itaconic anhydride, and maleic acid are preferred, and maleic anhydride is more preferred, from the viewpoint of improving adhesion to a nonpolar substrate.

The amine compound (C) has a hydrocarbon group. The hydrocarbon group may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group, and may be linear, branched, or cyclic. Examples of the hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group and an alkenyl group being preferred. The hydrocarbon group may have a substituent containing a heteroatom (eg, an atom other than a carbon atom or a hydrogen atom, such as an oxygen atom) as necessary. The number of carbon atoms in the hydrocarbon group is usually 6 or more or 7 or more, preferably 8 or more, and more preferably 12 or more. The upper limit is preferably 22 or less. The number of carbon atoms is preferably 6 to 22, 7 to 22, 8 to 22, or 12 to 22. When the number of carbon atoms is within the above range, the above-mentioned adhesion and solubility can be improved in a well-balanced manner. Furthermore, when applying the modified polyolefin resin, tack can be reduced.

The amine compound (C) only needs to have at least one hydrocarbon group, and may have two or more hydrocarbon groups.

The amine compound (C) is a compound having one or more nitrogen atoms, and usually has one nitrogen atom. Examples of the amine compound (C) include the amine compound (C1) represented by the general formula (1) and the amine compound (C2) represented by the general formula (2). The amine compound (C1) may be used alone or in combination of two or more. The same applies to the amine compound (C2). One or more amine compounds (C1) and one or more amine compounds (C2) may be used in combination.

General formula (1) is shown below.
H ₂ NR ¹¹ (1)
In formula (1), R ¹¹ represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group.

The straight-chain or branched saturated hydrocarbon group is usually a straight-chain or branched alkyl group, and a straight-chain alkyl group is preferred. The number of carbon atoms in the linear alkyl group is usually 6 or more or 7 or more, preferably 8 or more, and more preferably 12 or more. The upper limit is preferably 22 or less. The number of carbon atoms is preferably 6 to 22, 7 to 22, 8 to 22, or 12 to 22. When the number of carbon atoms is within the above range, the above-mentioned adhesion and solubility can be improved in a well-balanced manner. Tack can be reduced when coating modified polyolefin resin. If the number of carbon atoms is too small than 6, the adhesion between the resulting modified polyolefin resin and the nonpolar substrate may decrease, and tack may become large. Furthermore, if the number of carbon atoms is too large than 22, the solubility may decrease when the modified polyolefin resin is made into a solution.

The linear or branched unsaturated hydrocarbon group may have one double bond or triple bond, or may have two or more double bonds or triple bonds. Examples of the straight-chain or branched unsaturated hydrocarbon group include a straight-chain or branched alkenyl group, and a straight-chain or branched alkynyl group, with straight-chain alkenyl groups being preferred. . The number of carbon atoms in the linear alkenyl group is preferably 8 or more, more preferably 12 or more. The upper limit is preferably 22 or less. The number of carbon atoms is preferably 6 to 22, 7 to 22, 8 to 22, or 12 to 22. When the number of carbon atoms is within the above range, the above-mentioned adhesion and solubility can be improved in a well-balanced manner. Tack can be reduced when coating modified polyolefin resin. If the number of carbon atoms is too small than 6, the adhesion between the obtained modified polyolefin resin and the non-polar substrate may decrease, and tack may become large. If the number of carbon atoms is too large than 22, the solubility may decrease when the modified polyolefin resin is made into a solution.

General formula (2) is shown below.
HNR ²¹ R ²² (2)
In formula (2), R ²¹ and R ²² each independently represent a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group. Regarding the linear or branched saturated hydrocarbon group and the linear or branched unsaturated hydrocarbon group, the preferred ranges and reasons thereof are the same as those explained for the amine compound (C1).

Among these, the amine compound (C1) is preferred from the viewpoint of ease of modification to the polyolefin resin (A), and in the amine compound (C1), R ¹¹ in formula (1) has a carbon atom number of 8 to 22 alkyl groups are more preferred, and dodecylamine, stearylamine, caprylamine, and oleylamine are even more preferred. Thereby, the above-mentioned adhesion, solubility, and tackiness can be improved in a well-balanced manner.

The modified polyolefin resin usually contains an imide bond or an amide bond derived from the compound (B) and the amine compound (C). In other words, the modified polyolefin resin has a structure derived from the compound (B) grafted onto the polyolefin resin (A) (graft modification). Furthermore, a structure derived from the amine compound (C) is added via the structure derived from the compound (B) (additional modification). Therefore, a hydrocarbon group (R ¹¹ , R ²¹ or R ²² ) derived from the amine compound (C) is added to the modified polyolefin resin. Since the modified polyolefin resin has this hydrocarbon group introduced therein, it is considered that the above-mentioned adhesion is excellent.

Usually, when an acid anhydride of an unsaturated carboxylic acid is used as the compound (B), the acid anhydride group reacts with the amine compound (C) to form an imide bond. Usually, when an unsaturated carboxylic acid is used as the compound (B), its carboxy group portion reacts with the amine compound (C) to form an amide bond. All of the structures derived from the grafted compound (B) do not need to react with the amine compound (C) to form imide bonds or amide bonds. That is, it is sufficient that at least a part of the structure derived from the grafted compound (B) reacts with the amine compound (C) to form an imide bond or an amide bond.

Among these, it is preferable to use a combination of an acid anhydride of an unsaturated carboxylic acid and an amine compound (C1) as the compound (B), since a preferable amount of hydrocarbon groups can be introduced into the modified polyolefin resin. According to this combination, the above-mentioned adhesion and solubility can be improved in a better balance.

The weight average molecular weight of the modified polyolefin resin is preferably 15,000 to 300,000, more preferably 30,000 to 150,000, even more preferably 30,000 to 100,000, Particularly preferred is 50,000 to 100,000. When the weight average molecular weight is within the above range, the above-mentioned adhesion and solubility can be improved in a well-balanced manner.

The amount of compound (B) introduced into the modified polyolefin resin (graft weight) is, for example, 0.1 to 20% by weight when the modified polyolefin resin is 100% by weight. The modified weight (added weight) of the amine compound (C) in the modified polyolefin resin is, for example, 0.1 to 30% by weight when the modified polyolefin resin is 100% by weight. The graft weight of compound (B) can be determined by an alkaline titration method. When the modified weights of compound (B) and amine compound (C) are within the above range, the above-mentioned adhesion and solubility can be improved in a well-balanced manner.

The modified polyolefin resin may be further graft-modified with a radically polymerizable monomer. That is, the modifying component may contain a radically polymerizable monomer together with the compound (B) and the amine compound (C).

Examples of radically polymerizable monomers include (meth)acrylic compounds and vinyl compounds. A (meth)acrylic compound is a compound containing at least one (meth)acryloyl group (meaning an acryloyl group and/or a methacryloyl group) in the molecule. Examples of radically polymerizable monomers include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, cyclohexyl (meth)acrylate, hydroxyethyl (meth)acrylate, isobornyl ( meth)acrylate, glycidyl(meth)acrylate, octyl(meth)acrylate, lauryl(meth)acrylate, tridecyl(meth)acrylate, stearyl(meth)acrylate, cyclohexyl(meth)acrylate, benzyl(meth)acrylate, phenyl(meth)acrylate Acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, acetoacetoxyethyl (meth)acrylate, ) acrylate, N-methyl (meth)acrylamide, N-ethyl (meth)acrylamide, N-propyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-butyl (meth)acrylamide, N-isobutyl (meth)acrylamide , N-t-butyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N-methylene-bis(meth)acrylamide, N-methylol(meth)acrylamide, ) acrylamide, hydroxyethyl (meth)acrylamide, (meth)acryloylmorpholine, n-butyl vinyl ether, 4-hydroxybutyl vinyl ether, dodecyl vinyl ether and the like. Among them, methyl (meth)acrylate, ethyl (meth)acrylate, cyclohexyl (meth)acrylate, and lauryl (meth)acrylate are preferred, and among these, these methacrylates are more preferred. These can be used alone or in combination of two or more, and the mixing ratio can be freely set.

The (meth)acrylic compound preferably contains 20% by weight or more of at least one compound selected from (meth)acrylic esters represented by the following general formula (I). When the above (meth)acrylic compound is used, the molecular weight distribution of the modified polyolefin resin can be narrowed, and the solvent solubility of the modified polypropylene resin and the compatibility with other resins can be further improved.
CH ₂ =CR ₁ COOR ₂ (I)
In formula (I), R ₁ =H or CH ₃ , R ₂ =C _n H _2n+1 , and n = an integer from 1 to 18. Preferably, n is an integer from 8 to 18.

The graft weight of the radically polymerizable monomer in the modified polyolefin resin is preferably 0.1 to 30% by weight, more preferably 0.5 to 20% by weight. When the graft weight is less than 0.1% by weight, the solubility of the modified polyolefin resin and the compatibility and adhesiveness with other resins may decrease. If it is more than 30% by weight, it is undesirable because it forms an ultra-high molecular weight substance due to high reactivity and deteriorates solvent solubility, or it is undesirable because the amount of homopolymers and copolymers that are not grafted to the polyolefin skeleton increases. There may be no. When chlorine is not used as a polarizing agent, the amount of radically polymerizable monomer introduced (graft weight) in the non-chlorinated modified polyolefin resin is preferably 0.5 to 30% by weight, more preferably 1 to 20% by weight. %. The graft weight of the (meth)acrylic ester can be determined by ¹ H-NMR.

By the way, polyolefin resins such as polypropylene and polyethylene are general-purpose thermoplastic resins, and are inexpensive and have many excellent properties such as moldability, chemical resistance, weather resistance, water resistance, and electrical properties. For this reason, it has been used in a wide range of fields as sheets, films, molded products, etc. However, unlike polar base materials such as polyurethane resins, polyamide resins, acrylic resins, polyester resins, and metals, base materials made of these polyolefin resins (polyolefin base materials) have low polarity and are crystalline. , is known as a hard-to-adhere substrate. Therefore, it has the disadvantage that it is difficult to adhere and paint between the same and different types of substrates.

In order to improve this drawback, various methods have been attempted to introduce polar groups onto the surface of polyolefin substrates through treatments such as chemical treatment with chemicals, corona discharge treatment, plasma treatment, and flame treatment. However, these techniques have drawbacks such as the need for special equipment and their effectiveness decreasing over time.

Corona discharge treatment, which is often used as an adhesion treatment, treats the surface of the object to be treated (plastic base material) relatively deeply (than plasma treatment). For this reason, when a thin film (for example, a film with a thickness of 15 μm or less or less than 8 μm) is subjected to corona discharge treatment, holes are likely to be formed. Therefore, the reality is that corona discharge treatment cannot be practically used for such thin films.

On the other hand, a method has been devised in which a pretreatment agent having adhesive properties to the base material is coated on the surface of the base material in advance. For example, International Publication No. 2005/082963 pamphlet describes imparting polar groups to polyolefins by graft modification with unsaturated carboxylic acids and acrylic derivatives. A method has been discovered in which this is used as a coating agent to increase affinity with polypropylene substrates and improve adhesion. Although these methods have made it possible to coat and adhere to various polar substrates, such as polypropylene substrates, polyethylene substrates, which are more non-polar and have poor adhesion, do not have the adhesion effect necessary for practical use.

Polyethylene is broadly classified into low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), high-density polyethylene (HDPE), etc., depending on the manufacturing method and the resulting density differences. Adhesion to these substrates is difficult, for example, because polyethylene is non-polar, has low surface energy, and is highly crystalline.

On the other hand, Patent Document 1 describes a polyolefin resin modified with a polarity imparting agent and a copolymer of ethylene and α-olefin having 3 to 10 carbon atoms and having an unsaturated bond at one end. . It has been discovered that this modified polyolefin resin has adhesive properties with various types of polyethylene that have not been surface treated, and that it exhibits sufficient adhesive strength when treated at low temperatures. Furthermore, it has been shown to be useful as a modified polyolefin resin adhesive with low tack. However, when applied as a solution, the liquid state is poor and becomes cloudy. For this reason, a modified polyolefin resin with good liquid state and excellent transparency is required.

On the other hand, the modified polyolefin resin of the present invention has excellent adhesion to a base material of a composition containing a non-polar resin such as polyethylene (e.g. LDPE, LLDPE, HDPE) and It has a good liquid state and excellent transparency. Furthermore, it has excellent adhesive strength even to substrates that have not been subjected to surface treatment such as corona treatment.

The modified polyolefin resin of the present invention may be a chlorinated polyolefin resin. The chlorinated polyolefin resin is a resin in which the polyolefin resin (A) is modified with the above-mentioned modifying component and is further chlorinated. Chlorinated modified polyolefin resins may also exhibit the adhesion, solubility and transparency described above. Therefore, it is suitable as a heat sealant, adhesive, primer, or binder for paint or ink.

<Production method of modified polyolefin resin>
The method for producing the modified polyolefin resin of the present invention is not particularly limited as long as a modified polyolefin resin can be obtained by modifying the polyolefin resin (A) with a modifying component. For example, a method for producing a modified polyolefin resin includes a modification step of modifying the polyolefin resin (A) with a modifying component to obtain a modified polyolefin resin.

More specifically, in the modification step, first, the polyolefin resin (A) is graft-modified with the compound (B) to obtain an acid-modified polyolefin resin. A radical generator may be used during the graft polymerization reaction. A method for obtaining acid-modified polyolefin resin is a solution method in which compound (B) is heated and dissolved in a solvent such as toluene and a radical generator is added; compound (B) and Examples include a melt-kneading method in which a radical generator is added and kneaded. Here, the compound (B) may be added all at once or sequentially.

During the graft polymerization reaction, the compound (B) is used in an amount of 0.1 to 20 parts by mass based on 100 parts by mass of the polyolefin resin (A) from the viewpoint of grafting the compound (B) in a preferable amount. It is preferable.

The radical generator can be appropriately selected from known ones, but organic peroxide compounds are preferred. Examples of organic peroxide compounds include di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl 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, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyisopropyl carbonate, cumylperoxyoctoate , 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane. Among these, di-t-butyl peroxide, dilauryl peroxide, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane are preferred.

The amount of the radical generator added is preferably 1% by mass or more, more preferably 10% by mass or more, based on 100% by mass of the compound (B) used. Grafting efficiency can be maintained as it is 1% by mass or more. The upper limit of the amount added is preferably 200% by mass or less, more preferably 100% by mass or less. If the amount is 200% by mass or less, the reaction can be carried out economically.

The acid value of the acid-modified polyolefin resin is usually 0.5 mgKOH/g or more, preferably 5 mgKOH/g or more, and more preferably 10 mgKOH/g or more. The upper limit is usually 115 mgKOH/g or less, preferably 85 mgKOH/g or less, more preferably 60 mgKOH/g or less, particularly preferably 40 mgKOH/g or less, and particularly preferably 30 mgKOH/g or less.

The weight average molecular weight of the acid-modified polyolefin resin is usually 15,000 or more, preferably 20,000 or more, more preferably 30,000 or more, and particularly preferably 500,000 or more. The upper limit is usually 300,000 or less, preferably 150,000 or less, and more preferably 100,000 or less.

When obtaining an acid-modified polyolefin resin, the compound (B) that does not graft polymerize to the polyolefin resin (A), that is, unreacted substances, may be removed by extraction with a poor solvent, for example. In this way, an acid-modified polyolefin resin is obtained.

Next, the acid-modified polyolefin resin and the amine compound (C) are reacted (addition reaction) to obtain a modified polyolefin resin. A method for obtaining a modified polyolefin resin is a solution method in which an acid-modified polyolefin resin and an amine compound (C) are heated and dissolved in a solvent such as toluene or xylene. Examples include a melt-kneading method in which a modified polyolefin resin and an amine compound (C) are added, kneaded, and reacted by heating if necessary. Here, the amine compound (C) may be added all at once or sequentially.

In the addition reaction of the amine compound (C), the amine compound (C) is preferably used in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the acid-modified polyolefin resin. In this way, the above-mentioned modified polyolefin resin is obtained.

When the modified polyolefin resin is further graft-modified with a radically polymerizable monomer, it can be produced as follows. For example, in the modification step, first, polyolefin resin (A) is graft-modified with compound (B) and a radically polymerizable monomer to obtain an acid-modified polyolefin resin. During the graft polymerization reaction, a radical generator may be used as described above. Next, the acid-modified polyolefin resin and the amine compound (C) are reacted (addition reaction) to obtain a modified polyolefin resin.

Here, when using a (meth)acrylic compound as a radically polymerizable monomer, at least one compound selected from (meth)acrylic esters represented by formula (I) is added to the (meth)acrylic compound for 20 It is preferable to use it in an amount of % by weight or more. The radically polymerizable monomer is preferably used in an amount such that the graft weight in the modified polyolefin resin falls within the above-mentioned range.

When the compound (B) as a modifying component of the acid-modified polyolefin resin contains an acid anhydride having a cyclic structure containing a -CO-O-CO- group, the acid-modified polyolefin resin contains a structure derived from the cyclic structure. The structure derived from the cyclic structure in acid-modified polyolefin resin may take a closed ring structure (maintaining the cyclic structure) or may become an open ring structure due to the influence of moisture in the air, and usually both structures are It's mixed. In this specification, the ratio (%) of the ring-closed state to the structure derived from the cyclic structure (the total of the ring-closed structure and the ring-opened structure) possessed by the acid-modified polyolefin resin is referred to as the ring-closure ratio. The ring closure rate at the start of the reaction between the acid-modified polyolefin resin and the amine compound (C) is preferably 75% or more, more preferably 80% or more. By having a high ring closure rate, the reaction can proceed more efficiently and a modified polyolefin resin with better adhesion and solubility can be obtained. The upper limit of the ring closure rate is not particularly limited as long as it is 100% or less. The ring closure rate can be adjusted, for example, by dehydration reaction of the acid-modified polyolefin resin. The dehydration reaction may be carried out by heat treatment, and the heating temperature at that time is preferably 100°C or higher. The heat treatment may be performed under a nitrogen atmosphere if necessary.

The ring closure rate is measured by infrared absorption spectroscopy of the peak derived from the carbonyl group of the α,β-unsaturated carboxylic acid derivative that is ring-closed and the peak derived from the carbonyl group of the α,β-unsaturated carboxylic acid derivative that is ring-opened. It can be calculated from each measured value using the following formula:
(formula)
Ring closure rate R (%) = {B/(A+B)}×100
A: Peak height derived from the carbonyl group of the ring-opened α,β-unsaturated carboxylic acid derivative B: Peak height derived from the carbonyl group of the ring-closed α,β-unsaturated carboxylic acid derivative

Examples of the method for producing a chlorinated modified polyolefin resin include a method that further includes a chlorination step in addition to the above-mentioned modification step. The chlorination step is a step in which the modified polyolefin resin (non-chlorinated modified polyolefin resin) obtained in the modification step described above is chlorinated with chlorine to obtain a chlorinated modified polyolefin resin. Chlorination can be performed by a conventionally known method. A non-chlorinated modified polyolefin resin that is not chlorinated is suitable for adhesion of materials in which residual components derived from chlorine are undesirable. The timing of performing the chlorination step is not particularly limited, and may be performed prior to the above-mentioned modification step, during the modification step, or after the modification step.

<Applications of modified polyolefin resin>
The heat sealant, adhesive, primer, or paint or ink binder of the present invention contains the above-mentioned modified polyolefin resin. The modified polyolefin resin of the present invention may be used as a modified polyolefin resin composition in combination with other components as necessary. Modified polyolefin resins or modified polyolefin resin compositions are suitable as binders for heat sealants, adhesives, primers, paint binders, ink binders, etc. due to the above-mentioned excellent adhesion, solubility, and transparency.

Other components include curing agents, solvents, dispersion media, antioxidants, light stabilizers, ultraviolet absorbers, pigments, dyes, and inorganic fillers. These may be used alone or in combination of two or more.

Examples of the curing agent include polyisocyanate compounds, epoxy compounds, polyamine compounds, polyol compounds, and curing agents in which the functional groups of these compounds are protected with protective groups. When blending a curing agent, a catalyst such as an organic tin compound or a tertiary amine compound may be used in combination depending on the purpose.

Solvents or dispersion media include, for example, aromatic hydrocarbons (e.g. toluene, xylene), esters (e.g. ethyl acetate, butyl acetate, propyl acetate), aliphatic or cycloaliphatic hydrocarbons (e.g. cyclohexane, methylcyclohexane). , ethylcyclohexane, nonane, decane), alcohols (e.g., methanol, ethanol, propanol, isopropanol, butanol), and glycol ethers (e.g., propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol-t-butyl ether).

Furthermore, the modified polyolefin resin composition may contain other components used in adhesives (e.g., known adhesives such as polyester adhesives, polyurethane adhesives, acrylic adhesives, etc.) to the extent that the desired effects are not impaired. , other components used in heat sealants, other components used in primers, and other components used in binders may be blended.

EXAMPLES Hereinafter, the present invention will be explained in more detail based on Examples, but the present invention is not limited to these Examples.

[Example 1]
As the polyolefin resin (A), an olefin copolymer containing 89% by weight of propylene component and 11% by weight of ethylene component and having a weight average molecular weight of 260,000 was used. Based on 100% by weight of this olefin copolymer, 4% by weight of maleic anhydride and 1.5% by weight of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane were used. The mixture was supplied to an extruder and melted and kneaded at 210°C to cause a reaction. Thereby, an acid-modified polyolefin resin (A1) was obtained. The weight average molecular weight and acid value of the obtained acid-modified polyolefin resin (A1) were 98,000 and 24.3 mgKOH/g, respectively.
In a four-necked flask equipped with a stirrer, a cooling tube, and a dropping funnel, 100 parts by weight of acid-modified polyolefin resin (A1) and 100 parts by weight of xylene were combined and heated and stirred at 140°C under a nitrogen stream. Heating was continued until the resin was completely dissolved and the ring closure rate of maleic anhydride was 80% or more. Thereafter, 8 parts by weight of stearylamine was added and reacted for 2 hours. The obtained reaction solution was blown onto a vat and dried to obtain a modified polyolefin resin (A). The weight average molecular weight of the obtained modified polyolefin resin (A) was 78,000.

The ring closure rate R was measured by the following method.
First, a modified polyolefin resin was dissolved in an organic solvent to obtain a solution. Next, the solution was applied to a KBr plate, dried to form a thin film, and infrared absorption of 400 to 4000 cm ^-1 was measured using FT-IR (e.g. "FT/IR-4100", manufactured by JASCO Corporation). The spectrum was observed. The analysis was performed using attached software (eg, "Spectro Manager", JASCO Corporation).
The peak appearing at a wave number of 1700 to 1750 cm ⁻¹ was assigned to the peak derived from the carbonyl group of the ring-opened α,β-unsaturated carboxylic acid derivative, and the peak height was designated as A. The peak appearing at a wave number of 1750 to 1820 cm ⁻¹ was assigned to the peak derived from the carbonyl group of the ring-closed α,β-unsaturated carboxylic acid derivative, and the peak height was designated as B. Then, the ring closure rate R (%) was calculated from the formula (B/(A+B)×100).

[Example 2]
A modified polyolefin resin (A) was obtained in the same manner as in Example 1, except that 5 parts by weight of laurylamine was used instead of 8 parts by weight of stearylamine. The weight average molecular weight of the obtained modified polyolefin resin (A) was 73,000.

[Example 3]
A modified polyolefin resin (A) was obtained in the same manner as in Example 1, except that 8 parts by weight of oleylamine was used instead of 8 parts by weight of stearylamine. The weight average molecular weight of the obtained modified polyolefin resin (A) was 73,000.

[Example 4]
A modified polyolefin resin (A) was obtained in the same manner as in Example 1, except that 4 parts by weight of caprylamine was used instead of 8 parts by weight of stearylamine. The weight average molecular weight of the obtained modified polyolefin resin (A) was 76,000.

[Example 5]
As the polyolefin resin (A), an olefin copolymer having a propylene component of 80% by weight, a butene component of 20% by weight, and a weight average molecular weight of 300,000 was used. Based on 100% by weight of this olefin copolymer, 4% by weight of maleic anhydride and 3% by weight of di-tert-butyl peroxide were fed into a twin-screw extruder, melt-kneaded at 210°C, and reacted. I let it happen. Thereby, an acid-modified polyolefin resin (A2) was obtained. The weight average molecular weight and acid value of the obtained acid-modified polyolefin resin (A2) were 74,000 and 17.8 mgKOH/g, respectively.
A modified polyolefin resin (A) was obtained in the same manner as in Example 1 except that the acid-modified polyolefin resin (A2) was used. The weight average molecular weight of the obtained modified polyolefin resin (A) was 73,000.

[Example 6]
As the polyolefin resin (A), an olefin copolymer having a propylene component of 88% by weight, an ethylene component of 12% by weight, and a weight average molecular weight of 49,000 was used. To 114% by weight of this olefin copolymer, 4% by weight of maleic anhydride, 1.5% by weight of 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 3% by weight of lauryl methacrylate were added. These were supplied to a twin-screw extruder and melt-kneaded at 170° C. to react. Thereby, an acid-modified polyolefin resin (A3) was obtained. The weight average molecular weight and acid value of the obtained acid-modified polyolefin resin (A3) were 72,000 and 19.3 mgKOH/g, respectively.
A modified polyolefin resin (A) was obtained in the same manner as in Example 1 except that the acid-modified polyolefin resin (A3) was used. The weight average molecular weight of the obtained modified polyolefin resin (A) was 60,000.

[Comparative example 1]
An acid-modified polyolefin resin (A1) was obtained in the same manner as in Example 1. The acid-modified polyolefin resin (A1) and the amine compound (C) were not reacted.

[Comparative example 2]
An acid-modified polyolefin resin (A3) was obtained in the same manner as in Example 6. The acid-modified polyolefin resin (A3) and the amine compound (C) were not reacted.

[Comparative example 3]
100 parts by weight of an olefin copolymer with a propylene component of 97 mol%, an ethylene component of 3 mol%, and a weight average molecular weight of 80,000 (Tm=72°C), 5 parts by weight of maleic anhydride, 3 parts by weight of lauryl methacrylate, polyethylene (Weight average molecular weight 2,000, 97% of main chain ends having unsaturated bonds at one end, ethylene units 100 mol%, Mw/Mn 1.5) 40 parts by weight, and 1.5 parts by weight of di-t-butyl peroxide were kneaded and reacted using a twin-screw extruder set at 170°C. Remaining unreacted substances were removed by degassing under reduced pressure in the extruder. The resulting modified polyolefin resin had a weight average molecular weight of 66,000.

<Evaluation method>
The modified polyolefin resins obtained in Examples 1 to 6 and Comparative Examples 1 to 3 were evaluated according to the following method. The evaluation results are shown in Table 1.

(Adhesion test)
First, a solution was prepared by dissolving a modified polyolefin resin in toluene to have a solid content of 15%. Next, the above solution was applied to an unsurface-treated aluminum film using a #16 Mayer bar and dried for 24 hours in an environment of 23° C. and 50% humidity. After drying, a polyethylene film (linear low-density polyethylene (LLDPE) or high-density polyethylene (HDPE) film) that has not been surface-treated is superimposed on the resin-coated surface, and No. Heat sealing was performed using a 276 heat seal tester (Yasuda Seiki Seisakusho) at a pressure of 2.0 kgf/cm ² for 10 seconds. Each test piece was cut to a width of 15 mm and peeled off at a rate of 100 mm/min using a tensile tester to measure its peel strength. The test was conducted three times, the average value was taken as the peel strength, and the evaluation was performed according to the following evaluation criteria. All peeling occurred between the modified polyolefin resin layer and the polyethylene film.

・Evaluation criteria A: Peel strength is 200 gf/15 mm or more B: Peel strength is 150 gf/15 mm or more and less than 200 gf/15 mm C: Peel strength is 100 gf/15 mm or more and less than 150 gf/15 mm D: Peel strength is less than 100 gf/15 mm

(Tack test)
First, a solution was prepared by dissolving a modified polyolefin resin in toluene to have a solid content of 15%. Next, the above solution was applied to a polyethylene film that had not been surface-treated using a #10 Meyer bar, and dried for 24 hours at 23° C. and 50% humidity. After drying, the film was folded so that the coated surfaces overlapped, and after being lightly pressed with fingers, it was peeled off, and the tackiness was evaluated based on the ease with which it was peeled off.

・Evaluation criteria A: The film separates immediately after the finger is removed, and no tack is observed. B: The film separates within a few seconds after the finger is removed. C: More than 10 seconds have passed after the finger is removed. The film does not separate even when

(Solution appearance)
First, a solution was prepared by dissolving a modified polyolefin resin in toluene to have a solid content of 15%. Next, the above solution was put into a 225 mL bottle and left to stand in a constant temperature room at 21° C., and the appearance of the solution after one week had passed was visually confirmed. To evaluate solubility, the bottle containing the sample was observed from the side, and it was confirmed whether the letters on the opposite side were visible or not.

・Evaluation criteria A: Characters on the opposite side are clearly visible when viewed from the side (clear)
B: I can't see the characters (cloudy)

Claims (17)

The polyolefin resin (A) is modified with a modifying component,
The modifying component contains one or more compounds (B) selected from α,β-unsaturated carboxylic acids and acid anhydrides thereof, an amine compound having a hydrocarbon group (C) , and a radically polymerizable monomer. Mi ,
The hydrocarbon group possessed by the amine compound (C) is an alkyl group or alkenyl group having 6 to 22 carbon atoms,
Modified polyolefin resin. The modified polyolefin resin according to claim 1, wherein the modified polyolefin resin contains an imide bond or an amide bond derived from the compound (B) and the amine compound (C). The modified polyolefin resin according to claim 1 or 2, wherein the hydrocarbon group possessed by the amine compound (C) is an alkyl group or alkenyl group having 7 to 22 carbon atoms. Any one of claims 1 to 3, wherein the amine compound (C) is an amine compound (C1) represented by the following formula (1) or an amine compound (C2) represented by the following formula (2). The modified polyolefin resin described in .
H ₂ NR ¹¹ (1)
HNR ²¹ R ²² (2)
(In formula (1), R ¹¹ represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group, and in formula (2), R ²¹ and R ²² each independently represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group.) The amine compound (C) is an amine compound represented by the formula (1), and in the formula (1), R ¹¹ is an alkyl group or an alkenyl group having 7 to 22 carbon atoms. 4. The modified polyolefin resin according to 4. The modified polyolefin resin according to any one of claims 1 to 5, wherein the polyolefin resin (A) is a polymer containing a structural unit derived from ethylene. The modified polyolefin resin according to any one of claims 1 to 6, wherein the radically polymerizable monomer contains a (meth)acrylic compound and/or a vinyl compound . The modified polyolefin resin according to any one of claims 1 to 7, wherein the modified polyolefin resin is a chlorinated modified polyolefin resin. A heat sealing agent, adhesive, primer, or binder for paint or ink, comprising the modified polyolefin resin according to any one of claims 1 to 8. A modification step of modifying the polyolefin resin (A) with a modifying component to obtain a modified polyolefin resin,
The modifying component contains one or more compounds (B) selected from α,β-unsaturated carboxylic acids and acid anhydrides thereof, an amine compound having a hydrocarbon group (C) , and a radically polymerizable monomer. Mi ,
The hydrocarbon group possessed by the amine compound (C) is an alkyl group or alkenyl group having 6 to 22 carbon atoms,
A method for producing modified polyolefin resin. In the modification step, the polyolefin resin (A) is graft-modified with the compound (B) and a radically polymerizable monomer to obtain an acid-modified polyolefin resin, and then the acid-modified polyolefin resin and the amine compound (C) are The method for producing a modified polyolefin resin according to claim 10, which is a step of obtaining the modified polyolefin resin by reacting the modified polyolefin resin. The method for producing a modified polyolefin resin according to claim 10 or 11, wherein the modified polyolefin resin contains an imide bond or an amide bond derived from the compound (B) and the amine compound (C). The method for producing a modified polyolefin resin according to any one of claims 10 to 12, wherein the hydrocarbon group possessed by the amine compound (C) is an alkyl group or alkenyl group having 7 to 22 carbon atoms. Any one of claims 10 to 13, wherein the amine compound (C) is an amine compound (C1) represented by the following formula (1) or an amine compound (C2) represented by the following formula (2). A method for producing a modified polyolefin resin as described in .
H ₂ NR ¹¹ (1)
HNR ²¹ R ²² (2)
(In formula (1), R ¹¹ represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group, and in formula (2), R ²¹ and R ²² each independently represents a linear or branched saturated hydrocarbon group or a linear or branched unsaturated hydrocarbon group.) The amine compound (C) is an amine compound represented by the formula (1), and in the formula (1), R ¹¹ is an alkyl group or an alkenyl group having 7 to 22 carbon atoms. 15. The method for producing a modified polyolefin resin according to 14. The method for producing a modified polyolefin resin according to any one of claims 10 to 15, wherein the polyolefin resin (A) is a polymer containing a structural unit derived from ethylene. The modified polyolefin resin according to any one of claims 10 to 16, further comprising a chlorination step of obtaining a chlorinated modified polyolefin resin by chlorinating the modified polyolefin resin obtained in the modification step with chlorine. manufacturing method.