JP2019167448A - Adhesive resin composition, adhesion layer and laminate therewith - Google Patents

Abstract

To provide an adhesive resin composition having high adhesion strength to a styrenic resin layer and an ethylene/vinyl alcohol copolymer layer without using a tackifier and having excellent oil resistance.SOLUTION: An adhesive resin composition includes: a modified polyester-based elastomer (A) obtained by modifying a saturated polyester-based thermoplastic elastomer containing 58 to 73 mass% of polyalkylene ether glycol segment with an unsaturated carboxylic acid (derivative), and a propylene-based resin (B) satisfying the following conditions (B-i) and (B-II) or (B-iii), in which among 100 mass% of all of these, the modified polyester-based elastomer (A) is 25 to 65 mass%, and the propylene-based resin (B) is 35 to 75 mass%. (B-i) an amount of heat of fusion is 2 to 50 mJ/mg, (B-ii) a propylene/α-olefin copolymer where α-olefin is two kinds of ethylene, 1-butene, and 1-pentene, and (B-iii) is a propylene homopolymer.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive resin composition, and an adhesive layer and a laminate using the same. More specifically, the present invention relates to an adhesive resin composition containing a modified polyester elastomer and a propylene resin, an adhesive layer comprising the adhesive resin composition, and a laminate comprising the adhesive layer.

  Since ethylene-vinyl alcohol copolymer (hereinafter referred to as EVOH) has excellent gas barrier properties, the shelf life of food can be extended by applying a laminate containing an EVOH layer to food packaging materials. , Long-distance distribution and reduced food waste. However, since EVOH has a hydroxyl group that is a hydrophilic group, it is susceptible to humidity, and there is a problem that the gas barrier property deteriorates in a high humidity state. As a method for improving this defect, a method in which the EVOH layer is a laminate of a layer made of a resin having low moisture permeability such as polyolefin or polystyrene (hereinafter referred to as PS) is effective.

  Conventionally, it is known that polar group-grafted polyolefin is used as an adhesive resin for adhesion between EVOH and polyolefin. In this case, the adhesion mechanism is EVOH and polar group-grafted polyolefin. It is presumed that the group is bonded by a chemical interaction between the hydroxyl group of EVOH and the hydroxyl group of EVOH, while the polar group-grafted polyolefin and the polyolefin are compatible and exhibit an adhesive force.

  On the other hand, an adhesion method different from the adhesion between EVOH and polyolefin has been proposed for the adhesion between PS and EVOH. For example, Patent Document 1 and Patent Document 2 disclose a functional group grafted polyolefin and a styrene resin. And an adhesive resin composition containing a tackifier is disclosed. Here, the use of petroleum hydrocarbon resin, rosin or the like as the tackifier is disclosed.

Japanese Patent Laid-Open No. 10-265751 JP 11-35749 A

The adhesion method between PS and EVOH described in Patent Document 1 and Patent Document 2 uses a tackifier such as petroleum hydrocarbon resin or rosin, but both are inferior in oil resistance. When a laminate in which a PS layer and an EVOH layer are bonded with an adhesive layer made of an adhesive resin composition containing such a tackifier is used for the packaging of oily food, the tackifier dissolves into the oil from the adhesive layer. There was concern. As a result, when a laminated body in which the PS layer and the EVOH layer are bonded with such an adhesive layer is used as a food packaging material, the contents are restricted.
For these reasons, it is required to improve the oil resistance of the adhesive resin composition in order to expand the suitability of the contents.

  The present invention provides an adhesive resin composition having high adhesion strength to the PS layer and EVOH layer and excellent oil resistance without using a tackifier, and an adhesive layer and a laminate using the adhesive resin composition It is an issue to provide.

  The present inventor has intensively studied to solve the above problems, and does not include a tackifier by using a modified polyester elastomer having a specific structural unit and an adhesive resin composition containing a specific propylene resin. It has been found that it has excellent oil resistance and can adhere the styrene resin layer and the ethylene / vinyl alcohol copolymer layer with high strength.

  That is, the gist of the present invention is as follows.

[1] Obtained by modifying a saturated polyester thermoplastic elastomer having a polyalkylene ether glycol segment content of 58 to 73% by mass with an unsaturated carboxylic acid and / or a derivative thereof in the presence of a radical generator. A modified polyester-based elastomer comprising a modified polyester-based elastomer (A) and a propylene-based resin (B) satisfying the following conditions (Bi) and (B-ii), or (Bi) and (B-iii): The proportion of the modified polyester elastomer (A) in the total 100 mass% of the elastomer (A) and the propylene resin (B) is 25 to 65 mass%, and the ratio of the propylene resin (B) is 35 to 75 mass%. An adhesive resin composition.
(Bi) The heat of fusion is in the range of 2 to 50 mJ / mg.
(B-ii) a propylene / α-olefin copolymer, wherein the α-olefin is ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-hexene, 1 -At least two selected from the group consisting of octene and 1-nonene.
(B-iii) A propylene homopolymer.

[2] The adhesive resin composition according to [1], which does not contain a tackifier.

[3] The evaporation residue in the heptane elution test of the evaporation residue test method of the standard for foods and additives (Ministry of Health and Welfare Notification No. 370 in 1959) is 400 μg / ml or less, [1] or [2] The adhesive resin composition as described in 2.

[4] An adhesive layer comprising the adhesive resin composition according to any one of [1] to [3].

[5] A laminate comprising the adhesive layer according to [4].

[6] The laminate according to [5], wherein the layer in contact with one surface of the adhesive layer is a styrene resin layer, and the layer in contact with the other surface is an ethylene / vinyl alcohol copolymer layer.

  ADVANTAGE OF THE INVENTION According to this invention, the adhesive resin composition which is excellent in oil resistance and can express high adhesive strength with respect to PS layer and EVOH layer is provided, without using a tackifier. According to the adhesive resin composition of the present invention, a laminate suitable for a packaging material for oil-based foods can be obtained without being restricted by the contents even in food packaging applications.

The present invention will be described in detail below, but the following description is an example of an embodiment of the present invention, and the present invention is not limited to the following description unless it exceeds the gist. The present invention can be arbitrarily modified and implemented without departing from the scope of the invention.
In addition, in this invention, when expressing by putting a numerical value or a physical-property value before and behind using "-", it shall use as what includes the value before and behind.

[1] Adhesive resin composition The adhesive resin composition of the present invention comprises a saturated polyester thermoplastic elastomer having a polyalkylene ether glycol segment content of 58 to 73% by mass in the presence of a radical generator. 25 to 65% by mass of a modified polyester elastomer (A) obtained by modification with a saturated carboxylic acid and / or a derivative thereof, the following conditions (Bi) and (B-ii), or (Bi) and A total of 100 mass% of propylene-based resin (B) satisfying (B-iii) of 35 to 75 mass% is included.
(Bi) The heat of fusion is in the range of 2 to 50 mJ / mg.
(B-ii) a propylene / α-olefin copolymer, wherein the α-olefin is ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-hexene, 1 -At least two selected from the group consisting of octene and 1-nonene.
(B-iii) A propylene homopolymer.

[1-1] Modified polyester elastomer (A)
The modification in the present invention includes graft modification of a saturated polyester-based thermoplastic elastomer containing a polyalkylene ether glycol segment with an unsaturated carboxylic acid and / or a derivative thereof, terminal modification and modification by transesterification, modification by decomposition reaction, and the like. Say. Specifically, as the site to which the unsaturated carboxylic acid and / or the derivative thereof are bonded, a terminal functional group or an alkyl chain portion may be considered, and in particular, an ether bond of a terminal carboxylic acid, a terminal hydroxyl group and a polyalkylene ether glycol segment. On the other hand, carbon atoms at the α-position and β-position can be mentioned. In particular, it is presumed that the polyalkylene ether glycol segment is bonded to many α-position carbon atoms with respect to the ether bond.

  The saturated polyester thermoplastic elastomer that is a raw material of the modified polyester elastomer (A) is usually a block copolymer composed of a soft segment containing a polyalkylene ether glycol segment and a hard segment containing an aromatic polyester. It is important for the adhesive development that the soft segment is a polyalkylene ether glycol segment or a segment containing the same. In addition, unsaturated polyester elastomers containing double or triple bonds between the carbon atoms of the chief investigator tend to be colored by heat and light, and also generate gels during molding. In the present invention, a saturated polyester-based thermoplastic elastomer is used in the present invention because the composite laminate has a problem in appearance and is inappropriate.

  The content of the polyalkylene ether glycol segment in the saturated polyester thermoplastic elastomer that is the raw material of the modified polyester elastomer (A) needs to be 58 to 73% by mass in the saturated polyester elastomer, and preferably It is 60-70 mass%. If the content of the polyalkylene ether glycol segment is less than the above range, it is difficult to express sufficient adhesiveness to the styrene resin layer, and if it exceeds the above range, the material strength decreases and sufficient adhesion is achieved. It is difficult to obtain.

  Examples of the polyalkylene ether glycol constituting the soft segment include polyethylene glycol, poly (1,2 and 1,3-propylene ether) glycol, poly (tetramethylene ether) glycol, poly (hexamethylene ether) glycol, and the like. Can be mentioned. Particularly preferred is poly (tetramethylene ether) glycol.

  In the present invention, as the polyalkylene ether glycol, those having a number average molecular weight of 400 to 6000 are usually used, but those having 600 to 4000 are preferable, and those having 1000 to 3000 are particularly preferable. When the number average molecular weight is 400 or more, a sufficient modification effect can be obtained by the unsaturated carboxylic acid and / or its derivative, and good adhesiveness can be exhibited. On the other hand, when it is 6000 or less, phase separation hardly occurs in the system, and deterioration of physical properties of a polymer obtained by copolymerization or the like can be suppressed. The “number average molecular weight” here is measured by gel permeation chromatography (GPC). For calibration of GPC, a POLYTETRAHYDROFURAN calibration kit manufactured by POLYMER LABORATORIES, UK may be used.

Saturated polyester thermoplastic elastomers are usually
i) an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms;
ii) aromatic dicarboxylic acids and / or alicyclic dicarboxylic acids or their alkyl esters;
iii) A polyalkylene ether glycol having a number average molecular weight of 400 to 6000 is used as a raw material, and an oligomer obtained by an esterification reaction or a transesterification reaction can be polycondensed.

  As the aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, those usually used as a raw material for polyester, particularly as a raw material for a polyester-based thermoplastic elastomer, can be used. For example, ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like are mentioned, among which 1,4-butanediol and ethylene glycol are listed. 1,4-butanediol is particularly preferable. These diols can be used singly or as a mixture of two or more.

As the aromatic dicarboxylic acid and / or alicyclic dicarboxylic acid, those generally used as raw materials for polyesters, particularly polyester thermoplastic elastomers, can be used. For example, terephthalic acid, isophthalic acid, phthalic acid, 2, Examples include 6-naphthalenedicarboxylic acid and cyclohexanedicarboxylic acid. Among these, terephthalic acid and 2,6-naphthalenedicarboxylic acid are preferable, and terephthalic acid is particularly preferable. Two or more of these dicarboxylic acids may be used in combination.
When an aromatic dicarboxylic acid and / or an alicyclic dicarboxylic alkyl ester is used, the dimethyl ester or diethyl ester of the above dicarboxylic acid is used. Preference is given to dimethyl terephthalate and 2,6-dimethyl naphthalate.

  In addition to the above components, trifunctional triols, tricarboxylic acids or esters thereof may be copolymerized in a small amount, and aliphatic dicarboxylic acids such as adipic acid and dialkyl esters thereof are also used as copolymer components. Also good.

  As the kind of polyalkyl ether glycol and the preferred molecular weight range, those similar to those described above can be used.

  Commercially available products may be used as the saturated polyester-based thermoplastic elastomer comprising the polyester polyether block copolymer suitable for the present invention. For example, “Tefa Block” manufactured by Mitsubishi Chemical Corporation, “Perprene” manufactured by Toyobo Co., Ltd. -DuPont "Hytrel" can be used.

  Examples of unsaturated carboxylic acids and / or derivatives thereof used for modifying saturated polyester thermoplastic elastomers include acrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid. Unsaturated carboxylic acids; for example, 2-octen-1-yl succinic anhydride, 2-dodecen-1-yl succinic anhydride, 2-octadecene-1-yl succinic anhydride, maleic anhydride, 2, 3-dimethylmaleic anhydride, bromomaleic anhydride, dichloromaleic anhydride, citraconic anhydride, itaconic anhydride, 1-butene-3,4-dicarboxylic anhydride, 1-cyclopentene-1,2 -Dicarboxylic anhydride, 1,2,3,6-tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthal Acid anhydride, exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, methyl-5-norbornene-2,3-dicarboxylic acid Acid anhydride, endo-bicyclo [2.2.2] oct-5-ene-2,3-dicarboxylic acid anhydride, bicyclo [2.2.2. ] Unsaturated carboxylic anhydrides such as octo-7-ene-2,3,5,6-tetracarboxylic anhydride; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, Butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, glycidyl methacrylate, dimethyl maleate And unsaturated carboxylic acid esters such as maleic acid (2-ethylhexyl) and 2-hydroxyethyl methacrylate. Of these, unsaturated carboxylic acid anhydrides are preferred.

  The unsaturated carboxylic acid and / or derivative thereof may be appropriately selected according to the saturated polyester thermoplastic elastomer to be modified and the modification conditions, and two or more types may be used in combination. Unsaturated carboxylic acid and / or its derivative can also be added by dissolving in an organic solvent or the like.

  Examples of the radical generator used for performing a radical reaction in the modification treatment include t-butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl- 2,5-bis (tertiary butyloxy) hexane, 3,5,5-trimethylhexanoyl peroxide, t-butyl peroxybenzoate, benzoyl peroxide, dicumyl peroxide, 1,3-bis (t-butyl Peroxyisopropyl) benzene, dibutyl peroxide, methyl ethyl ketone peroxide, potassium peroxide, hydrogen peroxide and other organic and inorganic peroxides, 2,2-azobisisobutyronitrile, 2,2′-azobis (isobutyramide) ) Dihalide, 2,2'-azobi [2-methyl-N-(2-hydroxyethyl) propionamide], azo compounds such as azodi -t- butane, and carbon radical generators such as dicumyl like.

  These radical generators may be appropriately selected according to the type of saturated polyester-based thermoplastic elastomer used in the modification treatment, the type of unsaturated carboxylic acid and / or its derivative, and the modification conditions, and two or more types are used in combination. You may do it. The radical generator can be added after being dissolved in an organic solvent or the like.

Moreover, in order to further improve the adhesiveness of the resulting adhesive resin composition, a compound having an unsaturated bond can be used in combination as a modification aid in addition to the radical generator during the modification treatment.
The compound having an unsaturated bond refers to a compound having a carbon-carbon multiple bond other than an unsaturated carboxylic acid and / or a derivative thereof. Specifically, styrene, methylstyrene, ethylstyrene, isopropylstyrene, phenyl And vinyl aromatic monomers such as styrene and o-chloromethylstyrene. Improvement of the modification efficiency can be expected by these blends.

  The blending ratio of the unsaturated carboxylic acid and / or its derivative and radical generator used for the modification treatment is 0.01 to 30 parts by mass of the unsaturated carboxylic acid and / or its derivative with respect to 100 parts by mass of the saturated polyester elastomer. , Preferably 0.05 to 5 parts by mass, more preferably 0.1 to 2 parts by mass, particularly preferably 0.1 to 1 part by mass, and the radical generator is 0.001 to 3 parts by mass, preferably 0. 0.005 to 0.5 parts by mass, more preferably 0.01 to 0.2 parts by mass, and particularly preferably 0.01 to 0.15 parts by mass.

  When the blending amount of the unsaturated carboxylic acid and / or derivative thereof is not less than the above lower limit, the modification with the unsaturated carboxylic acid and / or derivative thereof can be sufficiently performed to exhibit good adhesiveness. Moreover, if it is below the said upper limit, it can prevent unsaturated carboxylic acid and / or its derivative | guide_body itself couple | bonding, and it will become a shame and generate | occur | produce the appearance defect and adhesion defect.

  Moreover, when the blending amount of the radical generator is not less than the above lower limit, the modification with the unsaturated carboxylic acid and / or its derivative can be sufficiently performed to exhibit good adhesiveness. Further, when the amount is not more than the above upper limit, a decrease in viscosity at the time of melting of the resulting modified polyester elastomer (A) can be suppressed, and sufficient shear can be applied when blended with the propylene resin (B). The dispersibility of the polyester-based elastomer (A) can be improved and good adhesiveness can be expressed.

  In the present invention, a blended component such as a saturated polyester-based thermoplastic elastomer, an unsaturated carboxylic acid and / or derivative thereof, a radical generator, and a compound having an unsaturated bond, which is a component added as necessary, is used. The blending method for obtaining the modified polyester elastomer (A) to be used includes a melting method, a solution method, a suspension dispersion method and the like, and is not particularly limited. Practically, the melt kneading method is preferable.

  Specific methods for melt kneading include powdered or granular saturated polyester thermoplastic elastomers, unsaturated carboxylic acids and / or derivatives thereof, radical generators, and components added as necessary. A compound having an unsaturated bond is uniformly mixed using a Henschel mixer, a ribbon blender, a V-type blender, etc. at a predetermined blending ratio, and then a multi-screw kneading extrusion such as a Banbury mixer, a kneader, a roll, a single screw or a twin screw. Examples thereof include a kneading method using a normal kneader such as a machine.

  The temperature of melt kneading of each component is usually in the range of 100 to 300 ° C, preferably in the range of 120 to 280 ° C, particularly preferably in the range of 150 to 250 ° C. Furthermore, the kneading order and method of each component are not particularly limited, and may be a saturated polyester-based thermoplastic elastomer, an unsaturated carboxylic acid and / or derivative thereof, a radical generator, and components added as necessary. A method of kneading a compound having a certain unsaturated bond at once or a method of kneading a part of each component and then kneading the remaining components may be used. However, the radical generator is preferably added at the same time as the unsaturated carboxylic acid and / or derivative thereof or the compound having an unsaturated bond from the viewpoint of improving the adhesiveness of the resulting modified polyester elastomer (A).

The amount of modification of the modified polyester elastomer (A) produced in this way analyzed by the infrared absorption spectrum method is preferably 0.01 to 15, more preferably 0.00. It is 03-2.5, More preferably, it is 0.1-2.0, Most preferably, it is 0.1-1.8.
A ₁₇₈₆ / (Ast × r)
[However, A ₁₇₈₆ is a peak intensity of 1786 cm ⁻¹ measured on a 20 μm thick film of the modified polyester elastomer (A), and As is a standard sample (content of polyalkylene ether glycol segment is 65). Is a peak intensity of a reference wave number measured for a film having a thickness of 20 μm (saturated polyester-based thermoplastic elastomer in mass%), and r is a molar fraction of the polyester segment in the modified polyester-based elastomer (A), It is the value divided by the molar fraction of the polyester segment in the standard sample. ]

A specific method for obtaining the value of the modified amount of the modified polyester elastomer (A) by the infrared absorption spectrum method is as follows.
That is, a 20 μm thick film-like sample is dried under reduced pressure at 100 ° C. for 15 hours to remove unreacted substances, and an infrared absorption spectrum is measured. From the obtained spectrum, the tangent line connecting the both sides of the foot of the mountain of the absorption band the baseline in the range of the absorption peak (1750~1820cm ^-1 by stretching vibration of the carbonyl group derived from an acid anhydride appears at 1786 cm ^-1 ) Is calculated as “peak intensity A ₁₇₈₆ ”.
On the other hand, the infrared absorption spectrum of a standard sample (saturated polyester thermoplastic elastomer having a polyalkylene ether glycol segment content of 65% by mass) with a thickness of 20 μm is measured in the same manner. From the obtained spectrum, in the case of an aromatic polyester-based thermoplastic elastomer containing a benzene ring, for example, in the case of an aromatic polyester-based thermoplastic elastomer, an absorption peak (850 to 900 cm) due to the CH out-of-plane variation angle of the benzene ring appearing at 872 cm ^−1. The peak height of the tangent line connecting the mountain hems on both sides of the absorption band in the range of ⁻¹ is set as the base line), and “peak intensity As” is calculated. The peak of the reference wave number may be selected from those that are not affected by denaturation and that do not have an absorption peak overlapping in the vicinity thereof.
From these two peak intensities, the amount of modification by the infrared absorption spectrum method is calculated according to the above formula. At that time, as r, a value obtained by dividing the mole fraction of the polyester segment in the modified polyester elastomer (A) for which the amount of modification is to be obtained by the mole fraction of the polyester segment in the standard sample is used. Moreover, the molar fraction mr of the polyester segment of each sample is the weight fraction (W ₁ and W ₂ ) of the polyester segment and the polyalkylene ether glycol segment, and the molecular weight of the monomer unit constituting both segments (e ₁ and e ₂ ) and is obtained by the following equation.
_{mr = (W 1 / e 1} ) / [(W 1 / e 1) + (W 2 / e 2)]

  The melt flow rate (MFR, 230 ° C., 2.16 kg, JIS K7210) of the modified polyester elastomer (A) used in the present invention is preferably 1 to 60 g / 10 minutes, more preferably 4 to 50 g / 10 minutes, more preferably 6 to 40 g / 10 minutes. The MFR of the modified polyester elastomer (A) is preferably higher than the MFR of the propylene resin (B). The modified polyester elastomer (A) responsible for adhesiveness becomes a sea phase, and needs to be in contact with an adherend such as PS or EVOH to develop adhesive strength. In general, it is known that an incompatible multi-component resin composition has a high MFR component as a sea phase and a low MFR component as an island phase. When the MFR of the modified polyester elastomer (A) is lower than the MFR of the propylene resin (B), the modified polyester elastomer (A) becomes an island phase and does not contact the adherend, so that the adhesive strength is not expressed. If the MFR of the modified polyester elastomer (A) exceeds the above upper limit, the MFR disparity with the propylene resin (B) is too large, a uniform dispersion structure cannot be taken, and adhesiveness is not exhibited. Further, if the MFR of the modified polyester elastomer (A) is less than the above lower limit, an island phase is formed and adhesiveness is not exhibited.

  The adhesive resin composition of the present invention may contain only one of the above-mentioned modified polyester elastomer (A), and may be a saturated polyester thermoplastic elastomer or unsaturated carboxylic acid used for modification and / or It may contain two or more of the derivatives having different types and physical properties.

[1-2] Propylene resin (B)
The propylene-based resin (B) used in the present invention needs to satisfy the following conditions (Bi) and (B-ii), or (Bi) and (B-iii).
(Bi) The heat of fusion is in the range of 2 to 50 mJ / mg.
(B-ii) a propylene / α-olefin copolymer, wherein the α-olefin, which is a comonomer of propylene, is ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, At least two selected from the group consisting of 1-hexene, 1-octene and 1-nonene.
(B-iii) A propylene homopolymer.

When the heat of fusion exceeds 50 mJ / mg, the affinity with the modified polyester elastomer (A) is poor, and the mechanical strength of the adhesive resin composition is lowered. That is, even if the adhesive strength with the styrene-based resin layer or ethylene / vinyl alcohol copolymer layer is good, the adhesive layer itself has low strength, resulting in cohesive failure of the adhesive layer and good adhesive strength is obtained. Absent.
A propylene resin having only one comonomer has poor affinity with the modified polyester elastomer (A), and the mechanical strength of the adhesive resin composition is lowered. In order to have sufficient affinity with the modified polyester elastomer (A), two or more kinds of comonomers are required.
In the case of a propylene homopolymer, the heat of fusion can be changed by controlling the stereoregularity. Affinity with the modified polyester elastomer (A) can be obtained by having low stereoregularity.

As described above, the propylene resin (B) needs to have a heat of fusion of 50 mJ / mg or less and a heat of fusion of 50 mJ / mg in order to maintain affinity with the modified polyester elastomer (A). If it exceeds 1, the amorphous component is not sufficient, and sufficient affinity with the modified polyester elastomer (A) cannot be obtained. The heat of fusion of the propylene-based resin (B) is preferably 45 mJ / mg or less, more preferably 40 mJ / mg or less. On the other hand, the lower limit of the heat of fusion is 2 mJ / mg or more, preferably 5 mJ / mg or more from the viewpoint of maintaining mechanical strength.
Note that the heat of fusion of the propylene-based resin (B) is measured by the method described in the Examples section described later.

The propylene-based resin (B) is a propylene / α-olefin copolymer, and the α-olefin is ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, It needs to be at least two selected from the group consisting of 1-hexene, 1-octene and 1-nonene. That is, it is a copolymer containing propylene as a main constituent unit and two or more different α-olefins other than propylene as constituent units. In the above α-olefin type, it is preferable that ethylene and 1-butene are included as copolymerization structural units.
When the propylene resin (B) is a propylene homopolymer, it is preferable that the stereoregularity is controlled and the stereoregularity is low.

  Further, the melt flow rate (MFR, 230 ° C., 2.16 kg, JIS K7210) of the propylene-based resin (B) used in the present invention is preferably 0.1 to 20 g / 10 minutes, more preferably 0.5. -15 g / 10 min, and more preferably 0.5-10 g / 10 min. When the MFR is at least the above lower limit, the MFR disparity with the modified polyester elastomer (A) is not too large, and sufficient dispersibility can be obtained by kneading. As a result, good adhesiveness can be obtained. Moreover, if MFR is below the said upper limit, sufficient moldability can be provided to the modified polyester-type elastomer (A) in which moldability is insufficient. In order to provide sufficient adhesion and moldability, it is preferable that the MFR of the propylene-based resin (B) is smaller than the MFR of the modified polyester-based elastomer (A).

  The adhesive resin composition of the present invention may contain only one kind of the above-mentioned propylene-based resin (B), or may contain two or more kinds having different monomer compositions and other physical properties. Good.

[1-3] Blending ratio The blending ratio of the modified polyester elastomer (A) and the propylene resin (B) constituting the adhesive resin composition of the present invention is the modified polyester elastomer with respect to 100% by mass in total. (A) needs to be 25-65 mass%, Preferably it is 30-60 mass%, More preferably, it is 35-55 mass%. If the modified polyester elastomer (A) is less than the above range, the adhesive strength is poor, and if it exceeds the above range, the fluidity is too high, so it is difficult to obtain a uniform film thickness during coextrusion molding, and it is easy to absorb moisture. Sometimes it foams, and it is difficult to obtain a laminate of good quality, resulting in poor moldability.

  On the other hand, the propylene-based resin (B) needs to be 35 to 75 mass% with respect to the total 100 mass% of the modified polyester elastomer (A) and the propylene-based resin (B), preferably 40 to It is 70 mass%, More preferably, it is 45-65 mass%. If the propylene resin (B) is less than the above range, the problem of moldability of the modified polyester elastomer (A) occurs, and if it exceeds the above range, the adhesiveness is inferior, which is not preferable.

  In the adhesive resin composition of the present invention, the proportion of the propylene-based resin (B) is preferably larger than that of the modified polyester-based elastomer (A). That is, in order to obtain moldability as an adhesive resin composition, it is preferable that the propylene resin (B) is a main component. On the other hand, in order to express good adhesiveness, a blending ratio of the specific modified polyester elastomer (A) is necessary as described above.

[1-4] Other additional components In addition to the modified polyester elastomer (A) and the propylene resin (B), the adhesive resin composition of the present invention has a purpose within the range that does not impair the objects and effects of the present invention. Depending on the, any component can be blended. Specifically, resin components other than the modified polyester elastomer (A) and the propylene resin (B), rubber components, talc, calcium carbonate, mica, fillers such as glass fibers, plasticizers such as paraffin oil, and antioxidants Agent, heat stabilizer, light stabilizer, ultraviolet absorber, neutralizer, lubricant, anti-fogging agent, anti-blocking agent, slip agent, crosslinking agent, crosslinking aid, colorant, flame retardant, dispersant, antistatic agent Various additives such as antibacterial agents and fluorescent brighteners can be added. Among them, it is preferable to add at least one of various antioxidants such as phenol, phosphite, thioether, and aromatic amine.

  However, since the tackifier causes the oil resistance to be impaired as described above, it is preferable that the adhesive resin composition of the present invention does not contain the tackifier. That is, the adhesive resin composition of the present invention contains the specific modified polyester elastomer (A) and the propylene resin (B), so that the adhesive resin composition can be used as an adhesive resin composition without blending a tackifier. The necessary characteristics can be fully satisfied.

[1-5] Production Method The adhesive resin composition of the present invention is prepared by variously known methods using a modified polyester elastomer (A), a propylene resin (B), and other additional components used as necessary. For example, by mixing using a tumbler blender, V blender, ribbon blender, Henschel mixer, etc., and after mixing, melt kneading with a single screw extruder, twin screw extruder, Banbury mixer, kneader, etc., and granulating or pulverizing Can be manufactured.

[1-6] Evaporation residue in heptane elution test The adhesive resin composition of the present invention is a heptane elution test of the evaporation residue test method of standard standards for foods and additives (Ministry of Health and Welfare Notification No. 370 in 1959). The evaporation residue in is preferably 400 μg / ml or less.
The evaporation residue in the heptane elution test is an index of oil resistance. If the evaporation residue in the heptane elution test is 400 μg / ml or less, the oil resistance is excellent, and it can be used for packaging a wide variety of contents.
The specific method for the heptane dissolution test is as described in the Examples section below.

[2] Adhesive layer and laminate The adhesive resin composition of the present invention is useful as an adhesive resin composition constituting the adhesive layer of the laminate, and in that case, an adhesive layer comprising the adhesive resin composition of the present invention. A thermoplastic resin such as a styrene resin, EVOH, a polyamide resin, a polyolefin resin, a polyester resin, an acrylic resin, or a polycarbonate resin is used as a layer in contact with the resin. Specifically, EVOH having an ethylene content of 15 to 60 mol%; polyester resins (PES resins) such as polyethylene terephthalate (PET), copolymerized PET, polybutylene terephthalate, polyethylene naphthalate, polycyclohexylene terephthalate; Polyamide resins (PA resins) such as 6-nylon, 6,6-nylon, 6-6, 6-nylon, 12-nylon, xylylene group-containing polyamide resins; polypropylene resins, polyethylene resins, ethylene / vinyl acetate Copolymers, ethylene / acrylic acid copolymers, ethylene / acrylic acid ester copolymers, polyolefin resins (PO resins) such as 4-methyl-1-pentene resin; general-purpose polystyrene, impact-resistant polystyrene, styrene・ Styrene such as methacrylic acid copolymer Resin (PS resin); Acrylic resin such as polyacrylonitrile, polymethyl methacrylate, acrylonitrile / methyl acrylate / butadiene copolymer; and polycarbonate resin (PC resin); and fillers such as resin and plate filler And a material such as a mixture thereof.

  Since the adhesive resin composition of the present invention is particularly excellent in the adhesion between the EVOH layer and the styrene resin layer, a laminate having a three-layer laminate structure of EVOH layer / adhesive layer / styrene resin layer at least partially. The adhesive resin composition of the present invention is particularly effective as a body adhesive layer constituent material.

  EVOH used for the layer in contact with the adhesive layer preferably has an ethylene content of 15 to 65 mol%, more preferably 25 to 50 mol%. When the ethylene content is too small, it is easily decomposed by heat and is difficult to be melt-molded, and it easily absorbs water and swells, resulting in poor water resistance. On the other hand, when the ethylene content is too high, the gas permeability resistance tends to decrease.

  The styrenic resin used for the layer in contact with the adhesive layer is a resin mainly composed of styrene such as a homopolymer of styrene, a copolymer of styrene and acrylonitrile, methyl (meth) acrylate, or a modified rubber thereof. Specifically, a thermoplastic resin called polystyrene, impact-resistant polystyrene (rubber-containing polystyrene), AS resin (SAN), ABS, SMA (styrene / maleic anhydride polymer), or the like is used.

  Although there is no restriction | limiting in particular in the thickness of the contact bonding layer which consists of the adhesive resin composition of this invention, It is preferable that it is the range of 5-100 micrometers from a viewpoint of suppressing thickness after obtaining sufficient adhesive force.

[3] Method for Producing Laminate As a method for producing the laminate of the present invention, various conventionally known methods can be employed. For example, blown films, T-die films, sheets, pipes, and melted individual resins made of the same gold are supplied by a coextrusion method in which individual molten resins melted by an extruder are supplied to a multilayer die and laminated in the die. Examples include co-injection molding in which a time lag is added to the mold and injection is performed.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely using an Example, this invention is not limited by an Example, unless the summary is exceeded.

[Modified polyester elastomer (A)]
<Constituent Material of Modified Polyester Elastomer (A)>
Saturated polyester thermoplastic elastomer A-1:
A polyester polyether block copolymer having polybutylene terephthalate as a hard segment and polytetramethylene ether glycol having a number average molecular weight of 2000 as a soft segment, wherein the content of the polytetramethylene ether glycol segment in the copolymer is 72% by mass of saturated polyester-based thermoplastic elastomer unsaturated carboxylic acid B-1: “Maleic anhydride (special grade)” manufactured by Wako Pure Chemical Industries, Ltd.
Radical generator C-1: NOF Corporation "NIPER BW" (benzoyl peroxide)

<Production of Modified Polyester Elastomer (A)>
Saturated polyester-based thermoplastic elastomer A-1: 100 parts by mass, unsaturated carboxylic acid B-1: 0.5 part by mass, radical generator C-1: 0.13 part by mass, Nippon Steel Works TEX- After melt-kneading in a 30-type kneader (diameter 30 mm, temperature 190 to 220 ° C.), the mixture was pelletized through a pelletizer to obtain a modified polyester elastomer (A).
The properties of the modified polyester elastomer (A) were evaluated by the methods shown below.

(1) Melt flow rate (MFR)
About the obtained pellet, MFR was measured on condition of temperature 230 degreeC and load 2.16kg based on JISK7210.

(2) Denatured amount by infrared absorption spectroscopy The sample obtained by molding the obtained pellets into a 20 μm-thick film by press molding (230 ° C.) was used, and an FT-IR apparatus (JASCO FT / IR610, JASCO) The amount of modification by infrared absorption spectrum method was calculated according to the procedure described in the text. The molar fraction of the polyester segment in the standard sample was 0.15, and Ast was 0.144.

The evaluation results of the modified polyester elastomer (A) are as follows.
MFR (230 ° C., 2.16 kg): 34 g / 10 minutes Denatured amount: 0.28

[Propylene resin (B)]
The following were used as propylene-type resin (B).
B-1: Propylene / α-olefin copolymer (Mitsui Chemicals, product name “Toughmer PN2060”)
Α-olefins other than propylene: ethylene and 1-butene MFR (230 ° C., 2.16 kg): 6 g / 10 minutes Heat of fusion: 15 mJ / mg
B-2: Propylene / α-olefin copolymer (manufactured by ExxonMobil Chemical Co., product name “VISTAMAX3000”)
Α-olefins other than propylene: ethylene MFR (230 ° C., 2.16 kg): 8 g / 10 min Heat of fusion: 25 mJ / mg
B-3: Propylene / α-olefin copolymer (Mitsui Chemicals, product name “Tafmer XM7070”)
Α-olefins other than propylene: 1-butene MFR (230 ° C., 2.16 kg): 7 g / 10 minutes Heat of fusion: 40 mJ / mg
B-4: Propylene / α-olefin copolymer (manufactured by Nippon Polypro, product name “WINTEC WFX4M”)
Α-olefins other than propylene: ethylene MFR (23 ° C., 2.16 kg): 7 g / 10 min Heat of fusion: 85 mJ / mg
B-5: Propylene homopolymer (manufactured by Nippon Polypro Co., Ltd., product name “NOVATEC PP MA3”)
Α-olefin other than propylene: not contained MFR (230 ° C., 2.16 kg): 10 g / 10 min Heat of fusion: 100 mJ / mg

  The physical properties of the propylene resin (B) were evaluated by the following methods.

(1) Melt flow rate (MFR)
In accordance with JIS K7210, MFR was measured under conditions of a temperature of 230 ° C. and a load of 2.16 kg.

(2) Heat of fusion Using a differential operating calorimeter (DSC), once the temperature was raised to 200 ° C and the thermal history was erased, the temperature was lowered to -10 ° C at a temperature drop rate of 10 ° C / min, and the temperature was raised again. The temperature at the top of the endothermic peak when measured at a rate of 10 ° C./min was taken as the melting peak temperature, and the integrated value of the endothermic peak from 20 ° C. to 180 ° C. was taken as the heat of fusion. The unit is mJ / mg.

[Example 1]
45% by mass of the modified polyester elastomer (A) and 55% by mass of the propylene resin (B-1) are blended, and after tumbler blending, a twin screw extruder (temperature 200 ° C., discharge rate 10 kg / hour, rotation speed 300 rpm) The resin composition was melt kneaded and extruded into a strand from a die and cut to produce an adhesive resin composition. The following adhesive evaluation and oil resistance evaluation were performed.
The results are shown in Table 1.

[Adhesion evaluation]
Using the obtained adhesive resin composition, using a T-die molding machine, four types and five layers of impact resistant polystyrene / adhesive resin composition / EVOH / adhesive resin composition / linear low density polyethylene are laminated. A film was formed. A film having a total thickness of 100 μm was obtained with a layer structure having a molding temperature of 230 ° C. and a line speed of 20 m / min and a thickness of each layer of 30/10/20/10/30 μm. “HT478” manufactured by PS Japan for the impact-resistant polystyrene layer, “EVAL F101B” (ethylene content: 32 mol%) manufactured by Kuraray for the EVOH layer, and manufactured by Nippon Polyethylene for the linear low-density polyethylene layer. “Novatech C6 SF8402” was used.
The obtained laminated film was cut into a strip of 15 mm width, and adhesion between one layer of impact-resistant polystyrene layer and four layers of adhesive resin composition / EVOH / adhesive resin composition / linear low density polyethylene The strength was measured by a T-type peel test at a peel rate of 300 mm / min. If the peel strength is 3 N / 15 mm or more, the adhesive strength is sufficient, and it can be used as a packaging material.

[Evaluation of oil resistance: Heptane dissolution test]
Referring to the heptane elution test of the evaporation residue test method of standard standards for foods and additives (Ministry of Health and Welfare Notification No. 370 in 1959), the following was performed.
The adhesive resin composition was press-molded (temperature 200 ° C., pressure 50 kgf / cm ² , 2 minutes) to produce a sheet having a thickness of 0.5 mm. The sheet was placed in a flask together with heptane and immersed at 25 ° C. for 1 hour to leach soluble components. Thereafter, 250 ml of the test solution was transferred to an eggplant type flask and concentrated under reduced pressure to make several ml. The concentrated solution and the washing solution obtained by washing the flask twice with about 5 ml of heptane were taken in a heat-resistant glass evaporating dish with a known weight previously dried at 105 ° C. and evaporated to dryness on a water bath. Next, after drying at 105 ° C. for 2 hours, the mixture was allowed to cool in a desiccator. Then, it weighed and calculated | required the weight difference before and behind an evaporating dish, and calculated | required the quantity of the evaporation residue by following Formula.
Evaporation residue (μg / ml) = (ab) × 1000 / amount of test solution collected (ml)
In the above formula, a is the weight difference (mg) before and after the evaporating dish, and b is the blank test value (mg) obtained for the same amount of heptane as the test solution.
If the evaporation residue in the heptane dissolution test is 200 μg / ml or less, the oil resistance is excellent, so that the suitability of the contents can be broadened as a packaging material.
The oil resistance evaluation was carried out only for those that exhibited high adhesive strength with an adhesive strength of 3 N / 15 mm or more.

[Examples 2 and 3 and Comparative Examples 1 to 4 and 7]
An adhesive resin composition was prepared in the same manner as in Example 1 except that the formulation was changed as shown in Table 1, and adhesion evaluation and oil resistance evaluation were performed.
In Comparative Examples 1 to 7, the adhesive strength was 3 N / 15 mm or less, which was insufficient, so the oil resistance test was not performed.
The results are shown in Table 1.

[Comparative Example 5]
Although an attempt was made to evaluate the adhesiveness of the modified polyester elastomer (A) alone, a laminated film could not be formed.

[Comparative Example 6]
Adhesive evaluation was performed for the propylene resin (B-1) alone. The results are shown in Table 1.

[Comparative Example 8]
Prior art tackifier blends were prepared as follows and evaluated for adhesion and oil resistance. The results are shown in Table 1.
100 parts by mass of a linear ethylene / 1-butene copolymer (density 0.920 g / cm ³ , MFR 2 g / 10 min (190 ° C., 2.16 kg)), and 1 part by mass of maleic anhydride, t-butyl par After mixing 0.04 parts by mass of oxybenzoate (Nippon Yushi Co., Ltd., Perbutyl D) with a super mixer for 1 minute, using a twin screw extruder (diameter 30 mm, L / D42), kneading temperature 230 ° C., screw rotation A modified ethylene polymer was obtained by melt-kneading under conditions of several 300 rpm and a discharge rate of 15 kg / hour, extruding this from a die into a strand, and cutting.
20 parts by mass of this ethylene-based polymer, 60 parts by mass of a linear ethylene / octene copolymer (density 0.870 g / cm ³ , MFR 1 g / 10 min (190 ° C., 2.16 kg)), Arakawa Chemical as a tackifier After mixing 20 parts by mass of “Arcon P-115” manufactured by Kogyo Co., Ltd. with a super mixer for 1 minute, using a twin screw extruder (diameter 30 mm, L / D42), kneading temperature 230 ° C., screw rotation speed 300 rpm, discharge The mixture was melt-kneaded under the condition of an amount of 15 kg / hour, extruded into a strand form from a die, and cut to obtain a conventional tackifier blend.

  As is apparent from Table 1, if the adhesive resin compositions of Examples 1 to 3 containing the modified polyester elastomer (A) and the propylene resin (B) within the specified range of the present invention, adhesion It exhibits strength of 3.8 N / 15 mm or more and sufficient adhesive strength, has little evaporation residue in the heptane elution test, and has good oil resistance. Thus, since adhesiveness and oil resistance are expressed with good balance, the suitability of the contents as a packaging material can be expanded.

Comparative Examples 1 and 2 are blended with propylene resin (B-2) or (B-3) in which only one α-olefin is a copolymer component other than propylene of the propylene / α-olefin copolymer. However, the adhesive strength was low. Since the adhesive strength is insufficient, there is a concern that contents leak due to delamination, which is inappropriate as a packaging material.
In Comparative Example 3, the propylene-α-olefin copolymer is a copolymer component other than propylene, and the α-olefin is only one kind, and the propylene-based resin (B-3) having a large heat of fusion is blended. The adhesive strength was low. Since the adhesive strength is insufficient, there is a concern that contents leak due to delamination, which is inappropriate as a packaging material.

  In Comparative Example 4, since there was no comonomer and a propylene homopolymer (B-5) having a large heat of fusion was blended, the adhesive strength was low. Since the adhesive strength is insufficient, there is a concern that contents leak due to delamination, which is inappropriate as a packaging material.

  In Comparative Example 5 using only the modified polyester elastomer (A), the fluidity at the time of melting is too high, so a laminate having a uniform thickness cannot be obtained by coextrusion molding, and the adhesion evaluation can be performed. could not. That is, it was difficult to apply the modified polyester elastomer (A) alone to the laminate.

  In Comparative Example 6 using only the propylene-based resin (B-1), since the modified polyester-based elastomer (A) is not blended, there is a concern that the adhesive strength is insufficient and content leakage due to delamination occurs. Yes, it is unsuitable as a packaging material.

  In Comparative Example 7, since the blending amount of the modified polyester elastomer (A) is small, the adhesive strength is insufficient, and there is a concern that the contents leak due to delamination, which is inappropriate as a packaging material.

  Comparative Example 8 satisfied the adhesive strength, but because it contained a tackifier with low oil resistance, the heptane elution amount increased, the oil resistance was inferior, and oil resistance such as oily food packaging was necessary. Not suitable for packaging materials.

Claims (6)

Modified polyester system obtained by modifying a saturated polyester thermoplastic elastomer having a polyalkylene ether glycol segment content of 58-73% by mass with an unsaturated carboxylic acid and / or derivative thereof in the presence of a radical generator. An elastomer (A) and a propylene-based resin (B) satisfying the following conditions (Bi) and (B-ii) or (Bi) and (B-iii): ) And propylene resin (B) in a total of 100% by mass, the proportion of the modified polyester elastomer (A) is 25 to 65% by mass, and the proportion of the propylene resin (B) is 35 to 75% by mass. Resin composition.
(Bi) The heat of fusion is in the range of 2 to 50 mJ / mg.
(B-ii) a propylene / α-olefin copolymer, wherein the α-olefin is ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-hexene, 1 -At least two selected from the group consisting of octene and 1-nonene.
(B-iii) A propylene homopolymer.   The adhesive resin composition according to claim 1, which does not contain a tackifier.   Adhesiveness according to claim 1 or 2, wherein the evaporation residue in a heptane elution test of the evaporation residue test method of the standard standard for foods, additives, etc. (Ministry of Health and Welfare Notification No. 370 in 1959) is 400 µg / ml or less. Resin composition.   The contact bonding layer which consists of an adhesive resin composition in any one of Claims 1-3.   A laminate comprising the adhesive layer according to claim 4.   The laminate according to claim 5, wherein the layer in contact with one surface of the adhesive layer is a styrene resin layer, and the layer in contact with the other surface is an ethylene / vinyl alcohol copolymer layer.