JP4781777B2 - Cap liner composition - Google Patents

Description

  The present invention provides a cap liner composition used for a sealing material for a beverage cap, which is excellent in sealing properties, gas barrier properties, hygiene, and easy to open in actual use, and uses the same. It is related to the cap liner. More specifically, the cross-linked isobutylene polymer has excellent flexibility, resilience and gas barrier properties, so that not only hermetic sealing performance is good, but also oxidation due to permeation of oxygen to the contents of soft drinks, etc., and internal pressure It is difficult for gas to escape from contents such as carbonated beverages, and it is easy to open during actual use by preventing abnormal increase in opening torque. In addition, elution from liner material is prevented. It is related with the composition for cap liners used for the sealing material of the cap for drinks excellent in the, and a cap liner using the same.

  Conventionally, liner materials such as cork, soft PVC, olefin resins such as low density polyethylene, and styrene elastomers have been used as liner materials for container lids such as glass bottles, metal bottles, and PET containers. Among these, although cork is excellent in impact resilience and the like, it is a natural material and has problems such as quality, supply stability, and dust generation. Further, although PVC-based materials are flexible and have excellent sealing properties, there are problems such as elution of plasticizers and generation of dioxins during low temperature incineration. Under these circumstances, in recent years, it has been changed to liner materials such as olefin resins and styrene elastomers having excellent hygiene and processability.

  However, when an olefin-based resin such as low-density polyethylene is used as the liner material, the sealing and sealing properties of contents that require high-temperature filling and heat sterilization treatment or contents such as carbonated beverages that are subject to internal pressure are subject to plastic deformation and permanent deformation. In this respect, there is a problem such as leakage, and there is also a problem with respect to leakage due to impact during transportation. For this reason, liner materials mainly composed of a styrene-based elastomer having excellent hermetic sealing properties are mainly used for the above-mentioned applications.

  As such a liner material mainly composed of a styrene-based elastomer, a composition comprising a hydrogenated styrene-butadiene block copolymer, a polyolefin, and a softening agent such as liquid paraffin is generally used. Yes (Patent Documents 1 to 4). By using such a composition, it is flexible and excellent in hermetic sealability, can withstand hot filling (hot fill) of the contents and heat sterilization after filling and sealing (retort sterilization), and can be thermally deformed or heated. A liner material in which leakage due to shrinkage is effectively eliminated can be obtained. However, on the other hand, hydrogenated styrene-butadiene block copolymer has higher gas permeability than polyolefin and low performance to block oxygen from the outside. There is a problem that the period in which the scent can be maintained is short. In addition, when the content is a carbonated beverage, there is a problem that the carbon dioxide gas escapes quickly and the period during which the internal pressure can be maintained is short. Furthermore, in order to express sufficient hermetic sealing properties, it is necessary to add a large amount of a softening agent such as liquid paraffin to impart flexibility. However, in a content containing fat such as a milk beverage, the softening agent Is easy to elute, and there is a problem in terms of hygiene.

  On the other hand, as a liner material excellent in gas barrier properties, a liner material mainly composed of butyl rubber has been proposed (Patent Document 5). However, in order to cross-link the butyl rubber described in Patent Document 5, it is necessary to use a cross-linking agent such as a phenol resin or zinc oxide, so there are problems such as coloring and smell of the liner material, The elution into the contents was high, and improvements were desired in terms of safety and hygiene.

Japanese Patent Laid-Open No. 2-57569 JP 7-76360 A JP-A-11-106565 JP 2000-38495 A JP 2002-160759 A

  The object of the present invention is a cap used as a sealing material for beverage caps, which has excellent sealing properties and gas barrier properties, is excellent in retort resistance (resistance to heat sterilization treatment), is hygienic, and can be easily opened in practical use. It is providing the composition for liners, and a cap liner using the same.

  As a result of intensive studies to solve the above problems, the inventors of the present invention obtained by dynamically crosslinking an isobutylene polymer having an alkenyl group at a terminal with a hydrosilyl group-containing compound in the presence of a polyolefin, The present inventors have found that the above problems can be solved by using a composition in which two or more kinds of predetermined additives are combined as a liner material, and have reached the present invention.

  That is, the present invention relates to (A) a composition obtained by melt-kneading an isobutylene polymer having an alkenyl group at the terminal with (B) a hydrosilyl group-containing compound in the presence of polyolefin, and (D) mono The present invention relates to a cap liner composition containing at least two additives selected from fatty acid amides, (E) bis fatty acid amides, and (F) fatty acid oils or paraffin oils.

  As a preferred embodiment, (A) 100 parts by weight of an isobutylene polymer having an alkenyl group at the terminal is melted with (C) a hydrosilyl group-containing compound in the presence of 10 to 100 parts by weight of a polyolefin. And a cap containing a total of 0.1 to 20 parts by weight of at least two additives selected from a composition and (D) a monofatty acid amide, (E) a bisfatty acid amide, and (F) a fatty acid oil or paraffin oil The present invention relates to a liner composition.

  As a preferred embodiment, further comprises (G) 1 to 300 parts by weight of a block copolymer comprising a polymer block (a) mainly composed of an aromatic vinyl compound and a polymer block (b) mainly composed of isobutylene. The present invention relates to a cap liner composition.

  As a preferable embodiment, the present invention further relates to a cap liner composition further comprising (H) 1 to 100 parts by weight of polybutene.

  As a preferred embodiment, the present invention further relates to (I) a cap liner composition containing 0.1 to 10 parts by weight of silicone oil.

  A preferred embodiment relates to a composition for a cap liner, wherein the polyolefin as the component (B) is at least one selected from polyethylene and polypropylene.

  A preferred embodiment relates to a composition for a cap liner, wherein the mono-fatty acid amide of component (D) is erucic acid amide.

  A preferred embodiment relates to a composition for a cap liner, wherein the bis-fatty acid amide of component (E) is at least one selected from ethylene bisoleic acid amide and ethylene bisstearic acid amide.

  A preferred embodiment relates to a cap liner composition, wherein the fatty acid oil of component (F) is epoxidized soybean oil.

  Moreover, this invention relates to the cap liner which consists of the said composition.

  A composition obtained by melt-kneading a hydrosilyl group-containing compound with an isobutylene polymer having an alkenyl group at the terminal as in the present invention in the presence of a polyolefin, and a combination of two or more predetermined additives. Thus, not only can the composition be excellent in sealing property and gas barrier property, and also excellent in retort resistance and hygiene, it becomes possible to achieve both bleed-out resistance and openability.

  The cap liner made of the composition of the present invention not only has good shape followability at the time of sealing, but also gas from contents such as carbonated drinks that are oxidized by the permeation of oxygen to the contents such as soft drinks and carbonated drinks that are subject to internal pressure. Omission is difficult to occur. In addition, an abnormal increase in the opening torque can be prevented, and opening during actual use can be easily performed. Furthermore, the elution of components from the liner material is prevented by crosslinking the alkenyl group of the isobutylene polymer with the hydrosilyl group-containing compound. As a result, a cap liner excellent in retort resistance and hygiene can be obtained. Therefore, it is suitable as a cap liner for soft drinks, carbonated drinks, milk drinks and the like.

  The cap liner composition of the present invention comprises (A) an isobutylene polymer having an alkenyl group at the terminal, and (B) a composition obtained by melt-kneading with a hydrosilyl group-containing compound in the presence of polyolefin, And (D) a monofatty acid amide, (E) a bisfatty acid amide, and (F) at least two additives selected from fatty acid oil or paraffin oil.

  The isobutylene polymer having an alkenyl group at the terminal, which is the component (A) of the present invention, is a unit derived from isobutylene accounting for 50% by weight or more, preferably 70% by weight or more, more preferably 90% by weight or more. Means a polymer having an alkenyl group at the terminal. The monomer other than isobutylene is not particularly limited as long as it is a monomer component capable of cationic polymerization, but aromatic vinyls, aliphatic olefins, dienes such as isoprene, butadiene, divinylbenzene, vinyl ethers, β -Monomers such as pinene can be exemplified. These may be used alone or in combination of two or more.

  Although there is no restriction | limiting in particular in the molecular weight of (A) component, It is preferable that it is 5,000 to 500,000 by weight average molecular weight by GPC measurement, and 10,000 to 200,000 is especially preferable. If the weight average molecular weight is less than 5,000, mechanical properties and the like may not be sufficiently developed. If it exceeds 500,000, the melt-kneading property is lowered, and the reactivity during crosslinking is also lowered. There is a risk.

  The alkenyl group in the component (A) of the present invention is not particularly limited as long as it is a group containing a carbon-carbon double bond that is active for a crosslinking reaction with a hydrosilyl group-containing compound. Specific examples of such an alkenyl group include aliphatic unsaturated hydrocarbon groups such as vinyl group, allyl group, methylvinyl group, propenyl group, butenyl group, pentenyl group, and hexenyl group, cyclopropenyl group, and cyclobutenyl group. And cyclic unsaturated hydrocarbon groups such as cyclopentenyl group and cyclohexenyl group.

  As a method for introducing an alkenyl group into the terminal of the component (A) of the present invention, there is a heavy group having a functional group such as a hydroxyl group as disclosed in JP-A-3-152164 and JP-A-7-304909. A method of introducing an unsaturated group into the polymer by reacting a compound having an unsaturated group with the polymer is exemplified. In order to introduce an unsaturated group into a polymer having a halogen atom, a method of performing a Friedel-Crafts reaction with alkenylphenyl ether, a method of performing a substitution reaction with allyltrimethylsilane in the presence of a Lewis acid, various phenols, etc. And a method of performing the above-described alkenyl group introduction reaction after introducing a hydroxyl group by performing a Friedel-Crafts reaction with. Among these, those in which an allyl group is introduced at the terminal by a substitution reaction of allyltrimethylsilane and chlorine are preferable from the viewpoint of reactivity.

  The amount of the alkenyl group in the component (A) of the present invention can be arbitrarily selected depending on the required properties, but from the viewpoint of the properties after crosslinking, it has at least 0.2 alkenyl groups per molecule at the end. It is preferably a polymer, more preferably 1.0 or more per molecule, and most preferably 1.5 or more per molecule. If it is less than 0.2, the crosslinking reaction may not proceed sufficiently.

  The polyolefin which is the component (B) of the present invention is an α-olefin homopolymer, a random copolymer, a block copolymer and a mixture thereof, or a random copolymer of an α-olefin and another unsaturated monomer. Polymers, block copolymers, graft copolymers and oxidized, halogenated or sulfonated ones of these polymers can be used alone or in combination of two or more. Specific examples of such polyolefins include polyethylene, ethylene-propylene copolymer, ethylene-propylene-nonconjugated diene copolymer, ethylene-butene copolymer, ethylene-hexene copolymer, and ethylene-octene copolymer. Polymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, ethylene-ethyl acrylate copolymer, ethylene-acrylic acid copolymer, ethylene-methyl acrylate-maleic anhydride copolymer, chlorination Polyethylene resins such as polyethylene, polypropylene, propylene-ethylene random copolymers, propylene-ethylene block copolymers, polypropylene resins such as chlorinated polypropylene, poly-1-butene, polyisobutylene, polymethylpentene, cyclic olefin (Co) polymer There can be exemplified. Among these, polyethylene, polypropylene, or a mixture thereof can be preferably used from the viewpoint of balance between cost and physical properties. Examples of the polyethylene include high density polyethylene, low density polyethylene, and linear low density polyethylene. Examples of the polypropylene include homopolypropylene, random polypropylene, and block polypropylene. Among these, polypropylene is most preferable from the viewpoint of heat resistance. Furthermore, it is preferable to use an ethylene-ethyl acrylate copolymer in combination from the viewpoint of flexibility and bleed-out property of the additive.

  Although there is no restriction | limiting in particular as a melt flow rate (MFR) of polyolefin to be used, it is preferable that it is 0.1-100 (g / 10min) from the point of shaping | molding fluidity | liquidity, and 1-100 (g / 10min) It is more preferable that

  In the present invention, the component (B) not only functions as a cross-linking reaction field for the component (A), but also functions to impart molding fluidity, heat resistance, mechanical strength, and openability to the final liner composition. Have. The amount of component (B) added is preferably 10 to 100 parts by weight and more preferably 20 to 80 parts by weight with respect to 100 parts by weight of component (A). When the amount of the component (B) is less than 10 parts by weight, sufficient molding fluidity may not be obtained, and when the amount is more than 100 parts by weight, flexibility may be impaired and sufficient sealing performance may not be exhibited.

In the present invention, the hydrosilyl group-containing compound (C) is used as the crosslinking agent for the component (A). Although there is no restriction | limiting in particular in the hydrosilyl group containing compound to be used, Various hydrosilyl group containing polysiloxane can be used preferably. Among them, a hydrosilyl group-containing polysiloxane having 3 or more hydrosilyl groups and 3 to 500 siloxane units is preferable, and a polysiloxane having 3 or more hydrosilyl groups and 10 to 200 siloxane units. More preferred are polysiloxanes having 3 or more hydrosilyl groups and 20 to 100 siloxane units. If the number of hydrosilyl groups is less than 3, sufficient network growth due to crosslinking may not be achieved and optimal rubber elasticity may not be obtained. If the number of siloxane units exceeds 500, the viscosity of polysiloxane is high (A). There is a possibility that the dispersibility in the component is lowered and the progress of the crosslinking reaction is insufficient. The polysiloxane unit mentioned here refers to the following general formulas (I), (II), and (III).
[Si (R ¹ ) ₂ O] (I)
[Si (H) (R ² ) O] (II)
[Si (R ² ) (R ³ ) O] (III)
As the hydrosilyl group-containing polysiloxane, a linear polysiloxane represented by the general formula (IV) or (V);
_{^{R 1 3 SiO- [Si (R}} 1) 2 O] a - [Si (H) (R 2) O] b - [Si (R 2) (R 3) O] c -SiR 1 3 (IV)
_{^{HR 1 2 SiO- [Si (R}} 1) 2 O] a - [Si (H) (R 2) O] b - [Si (R 2) (R 3) O] c -SiR 1 2 H (V)
(In the formula, R ¹ and R ² represent an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ³ represents an alkyl group having 1 to 10 carbon atoms or an aralkyl group. B represents 3 ≦ b, a, b. , C represents an integer satisfying 3 ≦ a + b + c ≦ 500.)
A cyclic siloxane represented by the general formula (VI);

(In the formula, R ⁴ and R ⁵ represent an alkyl group having 1 to 6 carbon atoms or a phenyl group, and R ⁶ represents an alkyl group having 1 to 10 carbon atoms or an aralkyl group. E represents 3 ≦ e, d, e , F represents an integer satisfying d + e + f ≦ 500.) And the like can be used.

  The component (A) and the hydrosilyl group-containing compound preferably have a hydrosilyl group amount (hydrosilyl group / alkenyl group) with respect to the alkenyl group in the range of 0.5 to 10 in terms of the crosslinking rate. 1 to 5 is particularly preferable. If the molar ratio is less than 0.5, crosslinking may be insufficient. If the molar ratio is more than 10, a large amount of active hydrosilyl groups remain after crosslinking, and volatile matter may be easily generated. .

  The crosslinking reaction between the component (A) and the component (C) proceeds by mixing and heating the two components, but it is preferable to add a hydrosilylation catalyst in order to advance the reaction more rapidly. Such hydrosilylation catalyst is not particularly limited, and examples thereof include radical generators such as organic peroxides and azo compounds, and transition metal catalysts.

  The radical generator is not particularly limited, and examples thereof include di-t-butyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di ( t-butylperoxy) -3-hexyne, dicumyl peroxide, t-butylcumyl peroxide, dialkyl peroxides such as α, α′-bis (t-butylperoxy) isopropylbenzene, benzoyl peroxide, p-chlorobenzoyl peroxide, m-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, diacyl peroxides such as lauroyl peroxide, peracid esters such as t-butyl perbenzoate, diisopropyl percarbonate, di-2-ethylhexyl percarbonate Peroxydicarbonate such as 1,1 Examples thereof include peroxyketals such as -di (t-butylperoxy) cyclohexane and 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane.

Also, it is not particularly limited as a transition metal catalyst, for example, platinum simple substance, alumina, silica, carbon black or the like dispersed in a platinum solid, chloroplatinic acid, chloroplatinic acid and alcohol, aldehyde, ketone, etc. And a platinum-olefin complex and a platinum (0) -dialkenyltetramethyldisiloxane complex. Examples of the catalyst other than platinum _{compounds, RhCl (PPh 3) 3,} RhCl 3, RuCl 3, IrCl 3, FeCl 3, AlCl 3, PdCl 2 · H 2 O, NiCl 2, TiCl 4 , and the like. These catalysts may be used alone or in combination of two or more. Of these, platinum vinylsiloxane is most preferred in terms of crosslinking efficiency.

Although there is no restriction | limiting in particular in the amount of catalysts, It is good to use in the range of 10 ^{< -1} > ^-10 <^-8> mol with respect to 1 mol of alkenyl groups of (A) component, Preferably it is the range of 10 ^{< -3} > ^-10 <^-6> mol. It is good to use. If the amount is less than 10 ⁻⁸ mol, the progress of crosslinking tends to be insufficient. If the amount exceeds 10 ⁻¹ mol, the heat generation is intense and the crosslinking reaction may not be sufficiently controlled.

  In the present invention, the components (A) and (C) are melt-kneaded in the presence of the component (B). Thereby, (A) component is bridge | crosslinked dynamically by (C) component. The melt kneading temperature is preferably 130 to 240 ° C. If the temperature is lower than 130 ° C., the component (B) may not be sufficiently melted and kneading may be uneven. At a temperature higher than 240 ° C., component (A) may be thermally decomposed. In this dynamic crosslinking step, the components (A), (B), and (C) are essential, but the components (D), (E), (F), (G), ( Crosslinking may be performed after adding other components such as component H) and component (I). However, since some of the components (D), (E), and (F) inhibit the crosslinking reaction, it is preferable to add them after crosslinking. In addition, when the crosslinking catalyst is added to the component (H) and then added, the catalyst is uniformly diffused, the components are uniformly mixed, and the uniformity of the crosslinking reaction can be improved. Therefore, such a method is preferable. Used. Furthermore, in order to promote the mixing of the component (A) and the component (B) and promote the uniform progress of the crosslinking reaction, the component (G) may be added in whole or in part before the crosslinking. preferable.

  There is no restriction | limiting in particular as a method for melt-kneading, A well-known method is applicable. For example, the component (A) and the component (B), and other components blended for obtaining predetermined physical properties are mixed with a heat kneader such as a single screw extruder, twin screw extruder, roll, Banbury mixer, It can be produced by melt-kneading using a lavender, kneader, high shear mixer or the like. Further, as the order of addition, after the component (B) is melted, the component (A) is added, and if necessary, other components are added and mixed uniformly, and then the crosslinking agent (component (C) ) And a crosslinking catalyst, and a method of allowing the crosslinking reaction to proceed is preferred.

  In the present invention, at least two types of (D) monofatty acid amide, (E) bisfatty acid amide, and (F) fatty acid oil or paraffin oil are used in combination. Thus, by using a combination of two or more additives, it is possible to greatly improve the plug-opening property and molding processability without using a large amount of additives. Therefore, bleeding out of the additive can be prevented, and a composition excellent in hygiene can be obtained.

  Specific examples of the mono-fatty acid amide as component (D) of the present invention include lauric acid amide, palmitic acid amide, erucic acid amide, oleic acid amide, stearic acid amide, arachidic acid amide, behenic acid amide, and eicosenoic acid. Examples include amides, linoleic acid amides, and linolenic acid amides. Among these, oleic acid amide and erucic acid amide are preferable, and erucic acid amide is most preferable from the viewpoints of the effect of improving the opening and molding processability and the influence on the flavor and aroma of the contents.

  Specific examples of the bis fatty acid amide as the component (E) of the present invention include ethylene bisoleic acid amide, ethylene biserucic acid amide, ethylene bislauric acid amide, ethylene bispalmitic acid amide, and ethylene bisbehenic acid. Examples thereof include amide, ethylene bislinoleic acid amide, and ethylene bislinolenic acid amide. Of these, ethylene bisoleic acid amide and ethylene bisstearic acid amide are preferred from the viewpoint of the effect of improving the opening and molding processability and the influence on the flavor and aroma of the contents. preferable.

  Specific examples of the fatty acid oil as component (F) of the present invention include stearic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, soybean oil, safflower oil, cottonseed oil, linseed oil, whale oil, tall oil , Sunflower oil, tung oil, castor oil, coconut oil, and epoxidized products thereof. Among these, epoxidized soybean oil is most preferable from the viewpoint of the effect of improving the opening and molding processability and the influence on the flavor and aroma of the contents.

  As the paraffin oil which is another component (F) of the present invention, paraffin oil obtained by refining mineral oil is preferable.

  The component (D), component (E), and component (F) of the present invention are preferably added in a total of 0.1 to 20 parts by weight of at least two selected from these components. More preferably 0.1 to 10 parts by weight, and still more preferably 0.1 to 5 parts by weight.

  When the added amount exceeds 20 parts by weight, the dispersibility becomes insufficient, and the (D) component, the (E) component, and the (F) component may bleed out, and the mechanical strength of the resulting composition is high. There is also a risk of lowering, which is not preferable. On the other hand, if the amount is less than 0.1 parts by weight, the effect of improving the opening torque and molding processability may be insufficient.

  In the present invention, for the purpose of improving molding fluidity, gas barrier properties, mechanical properties, and the like, the polymer block (a) mainly composed of an aromatic vinyl compound and an isobutylene as the main component (G) as necessary. A block copolymer comprising the polymer block (b) to be added can be added.

  The polymer block (a) mainly composed of an aromatic vinyl compound is a polymer block composed of 60% by weight or more, preferably 80% by weight or more of units derived from an aromatic vinyl compound.

  Aromatic vinyl compounds include styrene, o-, m- or p-methylstyrene, α-methylstyrene, β-methylstyrene, 2,6-dimethylstyrene, 2,4-dimethylstyrene, α-methyl-o. -Methylstyrene, α-methyl-m-methylstyrene, α-methyl-p-methylstyrene, β-methyl-o-methylstyrene, β-methyl-m-methylstyrene, β-methyl-p-methylstyrene, 2 , 4,6-trimethylstyrene, α-methyl-2,6-dimethylstyrene, α-methyl-2,4-dimethylstyrene, β-methyl-2,6-dimethylstyrene, β-methyl-2,4-dimethyl Styrene, o-, m- or p-chlorostyrene, 2,6-dichlorostyrene, 2,4-dichlorostyrene, α-chloro-o-chlorostyrene, α-chloro-m- Chlorostyrene, α-chloro-p-chlorostyrene, β-chloro-o-chlorostyrene, β-chloro-m-chlorostyrene, β-chloro-p-chlorostyrene, 2,4,6-trichlorostyrene, α- Chloro-2,6-dichlorostyrene, α-chloro-2,4-dichlorostyrene, β-chloro-2,6-dichlorostyrene, β-chloro-2,4-dichlorostyrene, o-, m- or p- t-butylstyrene, o-, m- or p-methoxystyrene, o-, m- or p-chloromethylstyrene, o-, m- or p-bromomethylstyrene, styrene derivatives substituted with silyl groups, indene And vinyl naphthalene. Among these, styrene, α-methylstyrene, and a mixture thereof are preferable from the viewpoint of industrial availability and glass transition temperature.

  The polymer block (b) mainly composed of isobutylene is a polymer block composed of 60% by weight or more, preferably 80% by weight or more of units derived from isobutylene.

  In any of the polymer blocks (a) and (b), a mutual monomer can be used as a copolymerization component, and other cationically polymerizable monomer components can be used. Examples of such a monomer component include monomers such as aliphatic olefins, dienes, vinyl ethers, silanes, vinyl carbazole, β-pinene, and acenaphthylene. These can be used alone or in combination of two or more.

  Aliphatic olefin monomers include ethylene, propylene, 1-butene, 2-methyl-1-butene, 3-methyl-1-butene, pentene, hexene, cyclohexene, 4-methyl-1-pentene, vinylcyclohexane Octene, norbornene and the like.

  Examples of the diene monomer include butadiene, isoprene, hexadiene, cyclopentadiene, cyclohexadiene, dicyclopentadiene, divinylbenzene, and ethylidene norbornene.

  Examples of the vinyl ether monomer include methyl vinyl ether, ethyl vinyl ether, (n-, iso) propyl vinyl ether, (n-, sec-, tert-, iso) butyl vinyl ether, methyl propenyl ether, ethyl propenyl ether and the like.

  Examples of the silane compound include vinyltrichlorosilane, vinylmethyldichlorosilane, vinyldimethylchlorosilane, vinyldimethylmethoxysilane, vinyltrimethylsilane, divinyldichlorosilane, divinyldimethoxysilane, divinyldimethylsilane, 1,3-divinyl-1,1,3. , 3-tetramethyldisiloxane, trivinylmethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylmethyldimethoxysilane, and the like.

  The component (G) of the present invention is not particularly limited as long as it is composed of the block (a) and the block (b), and has, for example, a linear, branched, or star structure. Any of a block copolymer, a diblock copolymer, a triblock copolymer, a multiblock copolymer, and the like can be selected. A preferable structure includes a triblock copolymer composed of (a)-(b)-(a) from the viewpoint of physical property balance and molding processability. These may be used alone or in combination of two or more in order to obtain desired physical properties and moldability.

  The ratio of the block (a) to the block (b) is not particularly limited, but from the viewpoint of flexibility and rubber elasticity, the content of the block (a) in the component (G) is 5 to 50% by weight. Is preferable, and it is further more preferable that it is 10 to 40 weight%.

  The molecular weight of the component (G) is not particularly limited, but is preferably 30,000 to 500,000 in terms of weight average molecular weight by GPC measurement from the viewpoint of fluidity, molding processability, rubber elasticity, and the like. 000 to 300,000 is particularly preferable. If the weight average molecular weight is lower than 30,000, the mechanical properties may not be sufficiently expressed, while if it exceeds 500,000, the fluidity and workability may be deteriorated.

Although there is no restriction | limiting in particular about the manufacturing method of (G) component, For example, it can obtain by polymerizing a monomer component in presence of the compound represented by following General formula (1).
(CR ¹ R ² X) _n R ³ (1)
[Wherein X is a halogen atom, a substituent selected from an alkoxy group having 1 to 6 carbon atoms or an acyloxy group, R ¹ and R ² are each a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbon atoms, R ¹ , R ² may be the same or different, R ³ is a polyvalent aromatic hydrocarbon group or a polyvalent aliphatic hydrocarbon group, and n represents a natural number of 1-6. ]

  The compound represented by the general formula (1) serves as an initiator, and is considered to generate a carbon cation in the presence of a Lewis acid or the like and serve as a starting point for cationic polymerization. Examples of the compound of the general formula (1) used in the present invention include the following compounds.

(1-Chloro-1-methylethyl) benzene [C ₆ H ₅ C (CH ₃ ) ₂ Cl], 1,4-bis (1-chloro-1-methylethyl) benzene [1,4-Cl (CH ₃ ) ₂ CC ₆ H ₄ C (CH ₃ ) ₂ Cl], 1,3-bis (1-chloro-1-methylethyl) benzene [1,3-Cl (CH ₃ ) ₂ CC ₆ H ₄ C (CH ₃ ) ₂ Cl], 1,3,5-tris (1-chloro-1-methylethyl) benzene [1,3,5- (ClC (CH ₃ ) ₂ ) ₃ C ₆ H ₃ ], 1,3-bis (1-Chloro-1-methylethyl) -5- (tert-butyl) benzene [1,3- (C (CH ₃ ) ₂ Cl) ₂ -5- (C (CH ₃ ) ₃ ) C ₆ H ₃ ]

Among these, bis (1-chloro-1-methylethyl) benzene [C ₆ H ₄ (C (CH ₃ ) ₂ Cl) ₂ ], tris (1-chloro-1-methylethyl) benzene [( ClC (CH ₃ ) ₂ ) ₃ C ₆ H ₃ ]. [Bis (1-chloro-1-methylethyl) benzene is also called bis (α-chloroisopropyl) benzene, bis (2-chloro-2-propyl) benzene or dicumyl chloride, and tris (1-chloro- 1-methylethyl) benzene is also referred to as tris (α-chloroisopropyl) benzene, tris (2-chloro-2-propyl) benzene, or tricumyl chloride.

When the component (G) is produced, a Lewis acid catalyst can be present together. Such Lewis acid may be any one that can be used for cationic polymerization. TiCl ₄ , TiBr ₄ , BCl ₃ , BF ₃ , BF ₃ .OEt ₂ , SnCl ₄ , SbCl ₅ , SbF ₅ , WCl ₆ , TaCl ₅ , VCl ₅ , FeCl ₃ , ZnBr ₂ , AlCl ₃ , AlBr _{3 and} other metal halides; Et ₂ AlCl, EtAlCl _{2 and} other organic metal halides can be suitably used. Of these, TiCl ₄ , BCl ₃ , and SnCl ₄ are preferable in view of the ability as a catalyst and industrial availability. The amount of Lewis acid used is not particularly limited, but can be set in view of the polymerization characteristics or polymerization concentration of the monomer used. Usually, it is 0.1-100 mol equivalent with respect to the compound represented by General formula (1), Preferably it is the range of 1-50 mol equivalent.

  In the production of the component (G), an electron donor component can be allowed to coexist if necessary. This electron donor component is believed to have the effect of stabilizing the growth carbon cation during cationic polymerization, and the addition of an electron donor produces a polymer with a narrow molecular weight distribution and a controlled structure. be able to. The electron donor component that can be used is not particularly limited, and examples thereof include pyridines, amines, amides, sulfoxides, esters, and metal compounds having an oxygen atom bonded to a metal atom.

  The polymerization of the component (G) can be carried out in an organic solvent as necessary, and the organic solvent can be used without particular limitation as long as it does not substantially inhibit cationic polymerization. Specific examples of such organic solvents include halogenated hydrocarbons such as methyl chloride, dichloromethane, chloroform, ethyl chloride, dichloroethane, n-propyl chloride, n-butyl chloride, and chlorobenzene; benzene, toluene, xylene, and ethylbenzene. Alkylbenzenes such as propylbenzene and butylbenzene; linear aliphatic hydrocarbons such as ethane, propane, butane, pentane, hexane, heptane, octane, nonane and decane; 2-methylpropane, 2-methylbutane, 2, Branched aliphatic hydrocarbons such as 3,3-trimethylpentane and 2,2,5-trimethylhexane; Cycloaliphatic hydrocarbons such as cyclohexane, methylcyclohexane and ethylcyclohexane; Mention paraffin oil, etc. Kill.

  These solvents can be used alone or in combination of two or more in consideration of the balance of the polymerization characteristics of the monomer constituting the component (G) and the solubility of the polymer to be formed.

  The amount of the solvent used is determined so that the concentration of the polymer is 1 to 50 wt%, preferably 5 to 35 wt% in consideration of the viscosity of the polymer solution obtained and the ease of heat removal.

  In carrying out the actual polymerization, each component is mixed at a temperature of, for example, −100 ° C. or more and less than 0 ° C. under cooling. In order to balance the energy cost and the stability of polymerization, a particularly preferred temperature range is −30 ° C. to −80 ° C.

  Component (G) is preferably mixed in an amount of 1 to 300 parts by weight, more preferably 1 to 200 parts by weight, based on 100 parts by weight of component (A). If it exceeds 300 parts by weight, the restoring property (compression set) may be deteriorated.

  In the present invention, polybutene ((H) component) can also be used as necessary for the purpose of imparting gas barrier properties, flexibility and molding fluidity. The polybutene is not particularly limited, but generally a liquid or liquid polybutene is preferably used at room temperature. Although there is no restriction | limiting in particular in molecular weight, From surfaces, such as fluidity | liquidity and a moldability, it is preferable that it is 200-25,000 by weight average molecular weight by GPC measurement, and it is especially preferable that it is 300-15,000. When the weight average molecular weight is as low as 300, heat resistance and gas barrier properties may not be sufficiently exhibited. On the other hand, when it exceeds 25,000, fluidity and workability may be deteriorated.

  The amount of component (H) is preferably 1 to 100 parts by weight, more preferably 1 to 50 parts by weight, and more preferably 1 to 30 parts by weight per 100 parts by weight of component (A). Is more preferable. When the amount exceeds 100 parts by weight, the softener tends to be eluted from the liner material to the contents, which is not preferable.

In the present invention, silicone oil can also be used as necessary as component (I) for the purpose of imparting moldability and openability. Although there is no restriction | limiting in particular as silicone oil, From the surface of fluidity | liquidity, workability, etc., the thing in the range of the viscosity in 25 degreeC is 10-500000 mm < ² > / cSt, and 100-50000 mm < ² > / cSt is especially preferable. Below 10 mm ² / cSt when there is a problem in heat resistance, the dispersibility tends deteriorate to exceed 500000mm ² / cSt. For the purpose of improving the mixing and dispersibility of the silicone oil, a master batch with polyolefin may be used. For example, silicone concentrate BY-27 series (manufactured by Toray Dow Corning Silicone Co., Ltd.), silicone master pellet X-22 series (manufactured by Shin-Etsu Chemical Co., Ltd.), hexasilicone ML series (manufactured by Hexa Chemical Co., Ltd.), etc. Goods.

  The amount of component (I) is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight, and more preferably 0.2 to 5 parts by weight per 100 parts by weight of component (A). More preferably, it is 3 parts by weight. If the amount is less than 0.1 parts by weight, the effect of improving the moldability may be poor. If the amount exceeds 10 parts by weight, the component (I) tends to be easily eluted from the liner material to the contents, which is not preferable.

  The cap liner composition of the present invention is excellent in gas barrier properties, but may further contain an oxygen absorbent for absorbing oxygen in the container and dissolved oxygen in the contents. As such an oxygen absorbent, known ones can be used, and there is no particular limitation. For example, ascorbic acid (vitamin C), ascorbate, isoascorbic acid, isoascorbate, gallic acid, gallate, propyl gallate, isopropyl citrate, glucose, fructose and other sugars, BHT, BHA, EDTA Alkali metal salt, tocopherol (vitamin E), hydroquinone, catechol, resorcin, dibutylhydroxytoluene, dibutylhydroxyanisole, pyrogallol, longalit, sorbose, glucose, lignin and other organic oxygen absorbers, iron powder, active iron, first oxide Iron-based oxygen absorbers such as iron and iron salt, inorganic oxygen absorbers such as sulfite, thiosulfate, dithionite, and bisulfite, polybutadiene, polyisoprene, or copolymers thereof, poly (Meta-xylenediamine-azi Acid) (for example, MXD6 manufactured by Mitsubishi Gas Chemical Co., Ltd. is commercially available), poly (ethylene-methyl acrylate-benzyl acrylate), poly (ethylene-methyl acrylate-tetrahydrofurfuryl acrylate), poly (ethylene -Methyl acrylate-cyclohexenyl methyl acrylate), polyhydric phenol-containing phenol-aldehyde resins, redox resins having an oxidizable (reducing) active group, or polymer-based oxygen absorption such as polymer metal complexes One or a mixture of two or more selected from oxygen adsorbents such as an adsorbent, zeolite, and activated carbon is appropriately used according to the conditions of use.

  When the oxygen absorbent is in a powder form, the particle size is not particularly limited, but in general, a smaller one is preferable in terms of increasing the surface area.

  The oxygen absorbent may contain other substances such as a catalyst, a water retention agent and a hydrate in order to control the oxygen absorption capacity. For example, an electrolyte can be used in combination with the iron-based oxygen absorbent.

The electrolyte is for accelerating the oxygen absorption rate of the iron-based oxygen absorbent, and examples thereof include alkali metal or alkaline earth metal halides, carbonates, sulfates and hydroxides. Among these, a halide is particularly preferable, and CaCl ₂ , NaCl, MgCl _{2 and the} like are more preferable. The electrolyte can be used by coating or blending with the iron-based oxygen absorbent particles.

  The amount of electrolyte added is generally about 0.1 to 10% by weight with respect to the iron-based oxygen absorbent.

  In addition, a transition metal catalyst for oxidation reaction can be used in combination with the oxidation-reduction resin used as the polymeric oxygen absorbent. Examples of the transition metal catalyst include metal salts such as acetic acid, naphthenic acid, stearic acid, acetylacetonate complex, or molybdenum of hydrochloric acid, iron, cobalt, rhodium, and nickel.

  Furthermore, a photosensitizer can be used in combination with the redox resin. As the photosensitizer that can be used, known ones such as a cleavage type and a hydrogen abstraction type can be used, but a hydrogen abstraction type is preferably used. Specific examples of the cleavage type include those having a benzoin derivative, benzyl ketal, α-hydroxyacetophenone, and α-aminoacetophenone skeleton. Examples of the hydrogen abstraction type photosensitizer include those having a benzophenone, Michler ketone, anthraquinone, or thioxanthone skeleton. These may be used alone or in combination.

  In addition, to the cap liner composition of the present invention, a thermoplastic resin, a thermoplastic elastomer, an unvulcanized rubber or the like other than the above may be added within a range not impairing the performance. As thermoplastic resins, polystyrene, acrylonitrile-styrene copolymer, polymethyl methacrylate, polyvinyl chloride, ABS, MBS, polycarbonate, polyethylene terephthalate, polybutylene terephthalate, polyamide, polyphenylene ether, polysulfone, polyamideimide, polyetherimide Etc. Examples of thermoplastic elastomers include styrene elastomers, olefin elastomers, vinyl chloride elastomers, urethane elastomers, ester elastomers, and nylon elastomers. Further, examples of the unvulcanized rubber include butyl rubber, natural rubber, butadiene rubber, isoprene rubber, styrene butadiene rubber (SBR), acrylonitrile butadiene rubber (NBR), acrylic rubber, and silicone rubber. Among these, when the component (G) is used, polyphenylene ether is preferably used for the purpose of improving its heat resistance. In addition, hydrogenated styrenic elastomers such as SEBS and SEPS are also preferably used for the purpose of adjusting moldability and openability.

  Further, for the purpose of improving the molding fluidity, a petroleum hydrocarbon resin can be added as necessary. The petroleum hydrocarbon resin is a resin having a molecular weight of about 300 to 10000 using petroleum unsaturated hydrocarbon as a direct raw material, for example, an aliphatic petroleum resin, an alicyclic petroleum resin and a hydride thereof, an aromatic resin. Petroleum resin and hydride thereof, aliphatic aromatic copolymer petroleum resin and hydride thereof, dicyclopentadiene petroleum resin and hydride thereof, low molecular weight polymer of styrene or substituted styrene, coumarone / indene resin, etc. . Among these, alicyclic saturated hydrocarbon resins are preferable from the viewpoint of compatibility with the component (A).

  Further, the cap liner composition of the present invention may be blended with a filler for improving physical properties or economic merit. Suitable fillers include clay, diatomaceous earth, silica, talc, barium sulfate, calcium carbonate, magnesium carbonate, metal oxide, mica, graphite, aluminum hydroxide and other flaky inorganic fillers, various metal powders, wood chips Examples thereof include glass powder, ceramic powder, carbon black, granular or powdered solid filler such as granular or powdered polymer, and other various natural or artificial short fibers and long fibers. Moreover, weight reduction can be attained by mix | blending the hollow filler, for example, inorganic hollow fillers, such as a glass balloon and a silica balloon, and the organic hollow filler which consists of a polyvinylidene fluoride and a polyvinylidene fluoride copolymer. Furthermore, various foaming agents can be mixed in order to improve various physical properties such as weight reduction and impact absorption, and it is also possible to mix gas mechanically during mixing. Among these, talc is preferable from the viewpoint of economy and hygiene.

  The blending amount of the filler is preferably 1 to 100 parts by weight, more preferably 1 to 50 parts by weight, and further preferably 1 to 30 parts by weight with respect to 100 parts by weight of component (A). preferable. If it exceeds 100 parts by weight, the flexibility of the resulting composition tends to be impaired, which is not preferable.

  Moreover, antioxidant and a ultraviolet absorber can be mixed with the composition for cap liners of this invention as needed. The blending amount is preferably 0.01 to 10 parts by weight and more preferably 0.01 to 5 parts by weight with respect to 100 parts by weight of component (A).

  In addition, flame retardants, antibacterial agents, light stabilizers, colorants, fluidity improvers, antiblocking agents, antistatic agents, etc. can be added as other additives, each of which can be used alone or in combination of two or more. Can be used.

  There is no restriction | limiting in particular in the manufacturing method of the composition for cap liners of this invention, A well-known method is applicable. For example, the above-mentioned components, and optionally additive components, are melted using a heat kneader, such as a single screw extruder, twin screw extruder, roll, Banbury mixer, Brabender, kneader, high shear mixer, etc. It can be manufactured by kneading. The kneading order of the components is not particularly limited, and can be determined according to the apparatus used, workability, or physical properties of the obtained cap liner composition.

  The hardness of the cap liner composition of the present invention is 40 to 95 as measured by a spring type A durometer defined by JIS K-6253 (hereinafter abbreviated as JIS-A hardness). Preferably, it is 45-70. When the JIS-A hardness is less than 40, the material strength of the liner is weak and the liner may be worn when the cap is opened and closed. When the JIS-A hardness exceeds 90, the liner is too hard and sufficiently adheres to the mouth of the container. It is difficult to seal the sealing contents of the container contents.

  In producing the cap liner of the present invention, although not particularly limited, various commonly used molding methods and molding apparatuses can be used according to the type, application, and shape of the target cap. Examples of the molding method include arbitrary molding methods such as injection molding, extrusion molding, press molding, blow molding, calendar molding, and casting molding, and these methods may be combined.

  As a method for producing a cap liner, for example, a cap liner composition is formed into a sheet having a thickness of 0.5 to 1.0 mm, then punched to a diameter suitable for the shape of the cap, and inserted into the cap to be bonded. Examples thereof include an in-shell molding method in which a certain amount of extruded molten resin is dropped inside a cap and is embossed under cooling to form a liner shape. The in-shell mold method is excellent from the viewpoint of mass productivity.

  The cap liner composed of the cap liner composition of the present invention may be used as a single layer or in combination with a layer having other functions. Examples of the layer having other functions include an oxygen absorption layer. Examples of the oxygen absorbing layer include a layer in which the aforementioned oxygen absorbent is dispersed in a polymer such as polyolefin.

  Caps in which the cap liner composition of the present invention is used include various types of tea beverages, fruit beverages, vegetable beverages, carbonated beverages, milk beverages, coffee beverages, soft drinks, mineral water PET bottle containers, metal bottle containers, beer And caps for containers used for bottles for alcoholic beverages such as whiskey, wine and sake, wide-mouthed bottles for food such as jam and enokitake, small bottles for drinks and the like. Among these, it is particularly suitable for a cap of a container used for a PET bottle container or a metal bottle container in terms of openability.

  Hereinafter, the present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by these Examples, In the range which does not change the summary, it can change suitably.

  The molecular weight of the block copolymer and the physical properties of the cap liner composition shown in this example were measured by the following methods.

(Molecular weight)
A GPC system manufactured by Waters (column: Shodex K-804 (polystyrene gel) manufactured by Showa Denko KK, mobile phase: chloroform) was used, and the weight average molecular weight was converted to polystyrene.

(Seal seal)
In accordance with JIS K-6253, three 2 mm thick press sheets were stacked, and the hardness (hereinafter abbreviated as JIS-A hardness) was measured with a spring type A durometer. The case where JIS-A hardness was 45-70 was set to (circle), the case of 40-45 or 70-95 was set to (triangle | delta), and the case where less than 40 or exceeded 95 was set to x.

(Openability)
For the test piece, a 1 mm thick press sheet produced by press molding at 170 ° C. for 5 minutes was attached to the bottom of a 38 mmφ metal can cap, and then the cap was left in an oven at 50 ° C. for 24 hours for 150 cc. Attached to a bottle of city water. The tightening angle of the cap was 75 ° from the place where the cap and the test sheet touched. A bottle with a cap is retorted on a pressure cooker PC305S manufactured by Hirayama Seisakusho under the condition of 125 ° C for 1 hour, and then left at room temperature for 5 days, using a torque meter 2TME450CN manufactured by Tohnichi Seisakusho. The opening torque was measured. A case where the opening torque was less than 180 N · cm, ○ was 180 to 200 N · cm, Δ was over 200 N · cm.

(Gas barrier properties)
Based on JIS K-7126, the permeability coefficient of oxygen was measured. As a test piece, a 1 mm thick press sheet was used, and a differential pressure method (A method) was used. The oxygen permeability coefficient is less than 1 × 10 ⁻¹⁵ mol · m / m ² · sec · Pa, ○, and 1 × 2 × 10 ⁻¹⁵ mol · m / m ² · sec · Pa is Δ, 2 × 10 ⁻¹⁵ mol · The case where it exceeded m / m < ² > * sec * Pa was set as x.

(Compression set)
In accordance with JIS K-6262, a 12.0 mm thick press sheet was used as a test piece. The measurement was carried out under the conditions of 70 ° C. × 22 hours and 25% deformation. When the deformation is 50% or more under these conditions, the restoring property is insufficient, and the sealing property is impaired after hot fill or retort sterilization. The case where it was less than 50% was marked as ◯, the case where it was 50-59% was marked as Δ, and the case where it was 60% or more was marked as x.

(Elution)
20 g of a 2 mm-thick press sheet produced by press molding at 170 ° C. for 5 minutes was precisely weighed, 10 times the amount of water was added and sealed, and heated at 121 ° C. for 1 hour. The mixture was allowed to cool to room temperature, 100 ml of the eluate was accurately measured, evaporated to dryness on a water bath, dried at 105 ° C. for 1 hour, and the weight of the residue was measured. Under these conditions, 2 mg or more of the eluate is x, 1-2 mg is Δ, 1 mg or less is o.

(Molding fluidity)
Based on JIS K-7210 method A, the flow rate per 10 minutes (MFR) was measured at 230 ° C. with a 2.16 kgf load. If it does not flow under these conditions, the molding fluidity is insufficient.

A cap liner composition was produced using the following raw materials.
Component (A) Isobutylene polymer having an alkenyl group at its terminal Component manufactured in Preparation Example 1 Component (B) Polyolefin Polypropylene (Random Type): Mitsui Polypro J215W (MFR: 9 g / 10 min, hereinafter RPP) manufactured by Mitsui Chemicals, Inc. Abbreviated)
Ethylene-ethyl acrylate copolymer: EVAFLEX EEA A702 (hereinafter abbreviated as EEA) manufactured by Mitsui DuPont Co., Ltd.
Component (C) Hydrosilyl group-containing compound (crosslinking agent)
Hydrosilyl group-containing polysiloxane Polysiloxane represented by the following chemical formula (hereinafter abbreviated as H-oil)
_{(CH 3) 3 SiO- [Si} (H) (CH 3) O] 48 -Si (CH 3) 3
Cross-linking catalyst 1,1,3,3-tetramethyl-1,3-dialkenyldisiloxane complex of zerovalent platinum, 3 wt% xylene solution (hereinafter abbreviated as Pt catalyst)
Component (D) Mono-fatty acid amide Erucamide: Nippon Seika Co., Ltd. Neutron-S (hereinafter abbreviated as EA)
Component (E) Bis-fatty acid amide Ethylene bis-stearic acid amide: Nippon Oil & Fats Alflow H50S (hereinafter abbreviated as EBS)
Ethylene bisoleic acid amide: EBO manufactured by CRODA JAPAN (hereinafter abbreviated as EBO)
Component (F) Fatty acid oil Epoxidized soybean oil: O-130P (hereinafter abbreviated as ESBO) manufactured by Asahi Denka Kogyo Co., Ltd.
Component (F) Paraffin oil Paraffin oil: Diana process oil PW380 (hereinafter abbreviated as PW380) manufactured by Idemitsu Kosan Co., Ltd.
Liquid paraffin: Liquid paraffin manufactured by Wako Pure Chemical Industries, Ltd.
Component (G) Isobutylene-based block copolymer Component manufactured in Production Example 2 below Component (H) Polybutene: Idemitsu Kosan Co., Ltd. Idemitsu Polybutene 100R (hereinafter abbreviated as 100R)
Component (I) Silicone oil: Silicone concentrate BY27-001 manufactured by Toray Dow Corning Silicone Co., Ltd., silicone oil content of about 50% (hereinafter abbreviated as SiMB)
Thermoplastic elastomer Hydrogenated styrene-butadiene block copolymer: Kraton Polymer Japan Co., Ltd. Kraton G1651 (styrene content 29%, hereinafter abbreviated as SEBS)

(Production Example 1) (A) Isobutylene copolymer having an alkenyl group at the terminal (hereinafter abbreviated as APIB)
A 2 L separable flask was fitted with a three-way cock, a thermocouple, and a stirring seal, and was purged with nitrogen. After nitrogen substitution, nitrogen was flowed using a three-way cock. To this, 785 ml of toluene and 265 ml of ethylcyclohexane were added using a syringe and cooled to about -70 ° C. After cooling, 277 ml (2933 mmol) of isobutylene monomer was added. After cooling to about −70 ° C. again, 0.85 g (3.7 mmol) of p-dicumyl chloride and 0.68 g (7.4 mmol) of picoline were dissolved in 10 ml of toluene and added. When the internal temperature of the reaction system became -74 ° C and stabilized, 19.3 ml (175.6 mmol) of titanium tetrachloride was added to initiate polymerization. When the polymerization reaction was completed (90 minutes), 1.68 g (11.0 mmol) of a 75 wt% -allyltrimethylsilane / toluene solution was added and reacted for another 2 hours. Thereafter, the reaction was stopped with pure water heated to about 50 ° C., and the organic layer was washed three times with pure water (70 ° C. to 80 ° C.), and the organic solvent was removed at 80 ° C. under reduced pressure to obtain APIB. . The weight average molecular weight by GPC measurement was 50000, and the contained allyl group determined by ¹ H-NMR was 2.0 / mol.

Production Example 2 (G) Isobutylene block copolymer, triblock structure having a styrene content of 30% (hereinafter abbreviated as SIBS)
After replacing the inside of the polymerization vessel of the 500 mL separable flask with nitrogen, add 97.6 mL of n-hexane (dried with molecular sieves) and 140.5 mL of butyl chloride (dried with molecular sieves) using a syringe. After the polymerization vessel was cooled in a dry ice / methanol bath at −70 ° C., the pressure-resistant glass liquefied collection tube with a three-way cock containing 47.7 mL (505.3 mmol) of isobutylene monomer was made of Teflon (registered trademark). The liquid feeding tube was connected, and the isobutylene monomer was fed into the polymerization vessel by nitrogen pressure. 0.097 g (0.42 mmol) of p-dicumyl chloride and 0.073 g (0.84 mmol) of N, N-dimethylacetamide were added. Next, 1.66 mL (15.12 mmol) of titanium tetrachloride was further added to initiate polymerization. After stirring for 75 minutes from the start of polymerization, about 1 mL of the polymerization solution was extracted from the polymerization solution for sampling. Subsequently, 13.71 g (131.67 mmol) of styrene monomer was added into the polymerization vessel. 75 minutes after adding the styrene monomer, the reaction was terminated by adding a large amount of water.

The reaction solution was washed twice with water, the solvent was evaporated, and the resulting polymer was vacuum-dried at 60 ° C. for 24 hours to obtain the desired block copolymer. When the GPC analysis of the obtained isobutylene type block copolymer was conducted, the weight average molecular weight was 135000 and the polystyrene content calculated | required by < ¹ > H-NMR was 30 weight%.

(Production Example 3) Dynamic cross-linking composition comprising component (A), component (B), and component (H) (component (B) is RPP, (A) / (B) / (H) = 100 / Example of 11/40 parts by weight (hereinafter abbreviated as TPV))
We measured 26.3 g of APIB (component (A)) obtained in Production Example 1 and 2.9 g of RPP (component (B)) and set Labo Plast Mill (Toyo Seiki Seisakusho Co., Ltd.) at 170 ° C. Then, 10.5 g of 100R (component (H)) was added and kneaded for another 2 minutes. Next, 0.32 g of H-oil (component (C)) which is a hydrosilyl group-containing compound (the amount of hydrosilyl group in component (C) relative to the alkenyl group in component (A) (hydrosilyl group / alkenyl group) is 4 equivalents. ) And kneaded for 1 minute, and then 14.8 μl of a crosslinking catalyst was added, and further melt-kneaded until the crosslinking proceeded and the torque value reached the maximum value. After kneading for 3 minutes after the torque value reached the maximum value, the dynamic cross-linking composition was taken out.

(Examples 1-9)
Lab Plast Mill (Toyo Seiki Co., Ltd.), which was blended so that the final composition of each component was as shown in Table 1, using the dynamic cross-linking composition TPV produced in Production Example 3. Melt-kneaded for 5 minutes. The charged weight was adjusted to 45 g in total. The obtained kneaded material was press-molded at 170 ° C. for 5 minutes to produce a sheet, and various physical properties were evaluated using this sheet. The evaluation results are shown in Table 1.

(Comparative Examples 1-8)
The same evaluation as in Examples 1 to 9 was performed except that the composition was changed as shown in Table 2. The results are shown in Table 2.

  Comparative Examples 1, 2, 3, 4, 5, and 6 correspond to Examples 1, 2, 3, 4, 8, and 6, respectively, and blends other than the components (D), (E), and (F) Are the same, but differ in that only one component is blended from the components (D), (E), and (F). The blending amount is equal to the sum of the components (D), (E), and (F) of the corresponding examples, but all of Comparative Examples 1 to 6 have a high opening torque of 210 N · cm. It can be seen that by using a plurality of components from the components (D), (E), and (F), the reduction in the opening torque is greatly increased.

  Comparative Example 7 is a composition mainly composed of a hydrogenated styrene-conjugated diene block copolymer (SEBS), which is a conventional technique, but it is understood that the gas barrier property is insufficient.

  On the other hand, Examples 1 to 9 of the present invention do not have such problems, and have hardness suitable for sealing, gas barrier properties, low opening torque, low compression set properties, low elution properties, and molding fluidity. It can be seen that the composition is well balanced as a liner material for the cap.

As described above, the composition according to the present invention can provide a cap liner that is the object of the present invention and has excellent hermetic sealing properties, gas barrier properties, restoration properties, hygiene, and can be easily opened during actual use. It has been shown.

Claims (8)

(A) a composition obtained by melting 100 parts by weight of an isobutylene polymer having an alkenyl group at a terminal in the presence of (B) 10 to 100 parts by weight of a polyolefin and (C) a hydrosilyl group-containing compound, and (D ) and mono-fatty acid amide, and (E) bis fatty acid amide, met (F) fatty oils or cap liner composition comprising a total of 0.1 to 20 parts by weight of at least two additives selected from paraffin oil And
The amount of the hydrosilyl group (hydrosilyl group / alkenyl group) of the (C) hydrosilyl group-containing compound relative to the alkenyl group of the component (A) is in the range of 0.5 to 10 in terms of molar ratio,
Furthermore, (I) The composition for cap liners containing 0.1-10 weight part of silicone oils. Further (G) according to claim 1 containing a block copolymer 1 to 300 parts by weight of a polymer block polymer block mainly composed of an aromatic vinyl compound and (a) mainly comprising isobutylene (b) The composition for cap liners. Further (H) cap liner composition according to any one of claims 1 to 2 containing polybutene 1-100 parts by weight. The composition for cap liner according to any one of claims 1 to 3 , wherein the polyolefin as the component (B) is at least one selected from polyethylene and polypropylene. (D) The mono-fatty acid amide of a component is erucic acid amide, The composition for cap liners in any one of Claims 1-4 characterized by the above-mentioned. The composition for a cap liner according to any one of claims 1 to 5 , wherein the bis-fatty acid amide as the component (E) is at least one selected from ethylene bis-oleic acid amide and ethylene bis-stearic acid amide. . The composition for cap liner according to any one of claims 1 to 6 , wherein the fatty acid oil of component (F) is epoxidized soybean oil. Cap liner composed of a composition according to any one of claims 1-7.