KR830000447B1 - Container lid with open liner - Google Patents

Abstract

No content.

Description

Container lid with open liner

1 is a partial cross-sectional side view showing the container lid of the present invention fastened to the container sphere.

2 is a plan view of the inside of the liner portion filter proof cap of the first embodiment.

3 is a sectional view taken along line III-III of the cap of FIG.

4 is a cross-sectional view of the bottle section used in the test of Example 2. FIG.

The present invention relates to a container lid provided with an olefin resin liner, and more particularly, to a container lid provided with a liner of an olefin resin composition that is excellent in sealing and easy opening.

Olefin resins such as low-density polyethylene have been widely used as sealing liners for container lids, having moderate cushioning properties and excellent hygienic properties. However, it has been found that various problems arise when the olefin resin liner is applied to a container lid. In other words, when the container lid including the olefin resin liner is fastened to the container mouth and stored for a long time, the opening torque of the container lid increases markedly with time, and the purchaser of the container It is often difficult to open the lid by hand.

In order to reduce the opening torque of the container lid, it is conceivable to include a lubricant in the olefin resin constituting the liner, but the lubricant added in the olefin resin migrates to the surface of the liner to seal the container lid. The disadvantage is that the initial torque is too small. In other words, when the initial torque of the sealing of the threaded container lid is excessively small, the sealing failure occurs during the initial tightening, or the loosening of the container lid occurs during the post-treatment process or transportation of the sealed container. There is leakage of outside oxygen.

SUMMARY OF THE INVENTION An object of the present invention is to provide a container lid having an olefin resin liner having an excellent squeezing property for sealing and opening property.

Another object of the present invention is to secure the torque sufficient to secure the sealing property at the beginning of the sealing of the container lid, and even if the sealing container is stored for a long time, an abnormal increase in the opening torque is suppressed. The result is to provide a container lid with an olefin resin liner that can be easily opened.

It is still another object of the present invention to provide a liner made of a novel olefin resin composition in which rapid migration of the lubricant to the surface of the liner is suppressed and a rise in opening torque is suppressed over time. It is to provide a container lid.

According to the present invention, 0.001 to 5% by weight of the base resin relative to 95 to 30% by weight of the crystalline polyolefin and 5 to 70% by weight of the low crystalline or amorphous copolymer of ethylene and other monoolefins. Lubricant, 1 to 15 per base resin

In Fig. 1 showing the container lid of the present invention together with the container fittings, the container lid shell 1 is downward from the periphery of the disc-shaped plate-shaped plate 2 formed of a coated metal plate and the plate plate. It is used as the cylindrical skirt skirt portion 3 which is loaded. Inside the container lid shell 1, a disk-shaped liner 3 made of an olefin resin composition is provided on the lower side of the top plate portion 2 with the adhesive layer 1 interposed therebetween.

The circumference of the liner 4 is engaged with the cylindrical spherical portion 7 of the container 6 to form a sealing structure, and the screw (3) of the neck of the container is provided on the skirt portion 3 of the container lid body 1. 8 and a screw 9 for opening and resealing are formed. In the skirt portion 3 of the container lid, a peeler proof mechanism may be provided that is close to the lower edge of the container lid and has a needle hole 10.

An important feature of the present invention is that this liner 4 is characterized in that the novel olefin composition described above, i.e., a crystalline polyolefin, a low crystalline or amorphous ethylene copolymer, a lubricant and a conjugated diene polymer in a specific amount ratio, It is in forming as a composition to contain.

First, in the present invention, as a base resin for forming a liner, a crystalline polyolefin (A) and a low crystalline or amorphous copolymer (B) made of ethylene and other monoolefins,

A: B = 95: 5 to 30: 70

Especially 92: 8 to 40: 60

The most suitable is to use it in a weight ratio of 90:10 to 70:30, which is extremely important for suppressing the increase in the opening torque over time. That is, the low crystalline to amorphous copolymer used in the present invention has a specific effect of suppressing the increase in the opening torque in the liner container lid when it is used as a liner in combination with polyolefin. This effect is hardly achieved when other amorphous polymers such as natural rubber, polybutadiene, styrene-butadiene copolymer rubber, nitrile-butadiene copolymer rubber, butyl rubber and the like are used. In addition, when the ethylene-based copolymer is blended with the crystalline polyolefin, the adhesion of the liner to the top plate of the container lid shell body is improved, and the flexibility or cushioning property of the liner is improved, and the sealing property is further improved. Additional advantages are also achieved.

In the present invention, as the crystalline polyolefin, the crystallinity is at least 40%

Wherein R is a hydrogen atom or an alkyl group having 4 or less carbon atoms. Polymers of at least one kind of olefin, in particular polyethylene polypropylene. The polyolefin to be used may contain a small amount of other olefins as a comonomer within a range that does not impair crystallinity, for example, 1 to 5 mol% of propylene, butene-1, etc. Crystalline ethylene copolymers can be used. The molecular weight of the crystalline polyethylene to be used should just be in the range which is sufficient to form a film generally. Most suitable for the purpose of the present invention

In addition, in this specification, a crystallinity degree is the crystallinity degree by the X-ray diffraction method described in Journal of Polymer Science Sci. Vol. 18, page 17-26, 1955 (SL Aggarwal and GD Tilley). Means.

In the present invention, as the low crystalline or amorphous ethylene copolymer, a copolymer of ethylene having a degree of crystallinity of less than 39% and particularly less than 10% can be used. Suitable examples of olefins other than ethylene are propylene, butene-1 and the like, and the copolymer may further contain nonconjugated dienes such as 1,4-hexadiene and ethylidene norbotene. Suitable examples of ethylene copolymers are copolymers containing 95 to 40 mol% ethylene, 5 to 60 mol% propylene or butene-1, or again 1 to 5 mol% nonconjugated dienes, in particular ethylene- Propylene copolymer rubber and ethylene-propylene-diene terpolymer copolymer rubber.

It is preferable that the molecular weight of these copolymers exists in the range of 5000-2 million especially 10000-1 million normally.

It is also important that these ethylene-based copolymers are combined with the crystalline polyolefin in the above ratios. In other words, when the amount of the ethylene copolymer is less than the above range, the effect of suppressing the increase in the opening torque over time is reduced, and the sealability of the liner itself is also lowered. On the other hand, when the content of the ethylene-based copolymer is larger than the above range, not only the initial torque at the time of sealing but also the torque at the time of opening becomes too large, and the purpose of easy opening cannot be achieved, and molding to a desired liner shape is achieved. It tends to be difficult.

In this invention, the combination of a lubricating agent and a conjugated diene copolymer is mix | blended with the base resin used as a combination of said crystalline polyolefin and a low crystalline to amorphous ethylene copolymer. When only the lubricant is blended into the base resin, the lubricant is transferred to the surface of the liner at the time of forming the liner and the rotational torque of the initial sealing is notably small. In contrast, in the present invention, when the combination of the lubricant and the conjugated diene copolymer is blended with the base resin, the conjugated diene copolymer suppresses the rapid transition of the active lubricant to the surface of the lubricant in the initial stage of molding. It is possible to maintain the initial rotational torque at a suitable value suitable for sealing and to maintain the opening torque even after long-term storage at the level of easy opening. Will be.

In the present invention, a lubricant having a kinematic coefficient of friction of 0.45 or less, in particular 0.25 or less, is suitably used as the lubricant in the case where 0.1 wt% of the low density polyethylene is blended separately from the composition of the present invention.

Suitable examples of such lubricants include, but are not limited to, the following.

(1) aliphatic hydrocarbon system

(2) silicon

Olugano polysiloxane

(3) fatty acids, aliphatic alcohols

Higher fatty acids

Hydrogenated fatty acids obtained from animal or vegetable fats and oils, containing 8 to 22 carbon atoms.

Hydroxy stearic acid

Straight-chain aliphatic monohydric alcohol

C4 or more carbon obtained by reducing animal or vegetable fats or oils and fatty acid esters or decomposing and dissolving natural lead.

Dodecyl Alcohol

(4) polyglycol

(5) amides, amines

Higher fatty acid amide

Orail Pearl Meat Amide

Stearyl erucamide

2-stearamide ethyl stearate

Ethylene Bis Fatty Acid Amide

NN 'oreoyl stearyl ethylene diamine

NN 'Bis (2hydroxyethyl) alkyl (C ₁₂ ~ C ₁₈ ) amide

NN 'Bis (hydroxyethyl) lauro amide

Oleic acid reacted with N alkyl (C ₁₆ ~ C ₁₈ ) trimethylene diamine

Fatty acid diethanolamine

Distearic acid ester of di (hydroxyethyl) diethylene triamine mono acetate

(6) fatty acid esters of monohydric and polyhydric alcohols

(7) triglycerides, wax

(8) Salts of alkali, metal, alkaline earth metals, zinc and aluminum of higher fatty acids (metal soap)

(9) low molecular weight olefin resin

(10) fluorine resin

(11) other

Propylene Glycol Alginate

Dialkyl ketone acrylic copolymers (e.g., modaflow from Monsanto).

In the present invention, as the lubricant, it is preferable to use an amide of a higher fatty acid, particularly a fatty acid amide having 16 to 22 carbon atoms. These have the advantage that it is excellent in the effect as a lubricating agent with respect to an olefin resin, and also excellent in the flavor retention property with respect to a container content.

The lubricant is formulated in an amount of 0.001 to 5% by weight, in particular 0.05 to 1.5% by weight and most suitably 0.1 to 0.8% by weight relative to the base resin. When the amount of the lubricant is less than the above range, the torque at the time of opening becomes too high, and therefore, the opening tends to be difficult, and when the amount of the lubricant is more than the above range, the torque at the initial stage of the sealing is too low to be a cause of poor sealing. There is this.

In the present invention, examples of the conjugated diene polymer used as the active sustaining agent include homopolymers of conjugated dienes or copolymers of conjugated dienes with other ethylenically unsaturated monomers. As conjugated diene, it is formula

In the formula, R ¹ represents a hydrogen atom, a halogen atom, or an alkyl group having 4 or less carbon atoms.

Dienes such as butadiene, isoprene and chloroprene. As an ethylenically unsaturated monomer, Vinyl aromatic monomers, such as styrene, vinyltoluene, and (alpha) -methylstyrene; Ethylenic unsaturated carbon acids or esters thereof, such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fmaric acid, itaconic anhydride, crotonic acid, and citraconic anhydride, amides, hydroxyalkyl esters and aminoalkyl esters Acrylic monomers such as resins; Vinyl ester monomers such as vinyl acetate, vinyl formate, and vinyl propionate; Ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; Vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; One or two or more types of vinyl halides, such as vinyl chloride and vinylidene chloride, can be mentioned.

The conjugated diene polymer used in the present invention also contains at least 10% by weight, particularly preferably 20% by weight, of conjugated diene units, which is extremely important in view of the above-mentioned active sustainability.

Suitable examples of conjugated diene polymers include natural or synthetic rubbers such as cis-1,4-polybutadiene, polyisoprene, styrene-butadiene rubber, nitrile-butadiene copolymer rubber, polychloroprene, thermoplastic butadiene copolymers and thermoplastic isoprene. Copolymer. Suitable thermoplastic butadiene copolymers or thermoplastic isoprene copolymers are styrene-butadiene (or isoprene) block copolymers containing 15 to 40% by weight of butadiene or isoprene units, or styrene-butadiene (or isoprene) -styreneblock copolymers.

It is preferable that the molecular weight of these conjugated diene polymers generally exists in the range of 10,000 to 1,000,000.

In the present invention, it is also important to use the conjugated diene polymer in an amount of 1 to 15% by weight, in particular 1 to 10% by weight, most preferably 2 to 7% by weight, per base resin. When the amount of the conjugated diene polymer is less than the above range, the opening torque in the initial stage of sealing is too low, and problems such as poor sealing and leakage are likely to occur. On the other hand, when the amount of the conjugated diene polymer is larger than the above range, the migration of the lubricant to the liner surface may be completely suppressed, and the opening torque may be too high.

In the present invention, the opening torque of the initial seal is 1 kg-cm or more, in particular 2 kg-cm or more, and the consumer's opening torque is 20 kg-cm or less It can be less than 13kg-cm.

The olefine resin composition which concerns on this invention can be mix | blended by the prescription which makes known the well-known arbitrary compounding agents. For example, in order to color the liner or impart opacity, white pigments such as titanium dioxide, colored pigments such as carbon black, red iron oxide, and taratazine lake, fillers such as calcium carbonate, talc, clay, and barium sulfate are used. It can mix. In order to prevent the blocking, an anti-blocking agent such as silica may be blended with an antioxidant such as an externally harmful phenol to prevent thermal degradation during liner processing or sterilization.

Molding of the olefin resin composition of the present invention into a liner can be performed by any means. For example, after melt-kneading each of the above components, by extruding a predetermined amount into the inside of the container lid shell body, by pressing the resin composition under cooling, it can be formed into a liner in place. According to this molding method, the sealability of the liner periphery to be fastened to the container spout is

Alternatively, the olefin resin composition of the present invention may be molded into a sheet by melt extrusion or roll forming, or the like, and the sheet may be punched into a disc shape, and the disc may be provided one by one in a container lid body with a rhino. In this case, the sheet for forming a liner may be a single layer of the olefin resin composition of the present invention, or may be a laminate of at least the surface to be fastened with the container spherical part of the layer of the olefin resin composition of the present invention. Such a laminate may be formed by dry lamination, extrusion coating method, coextrusion of a layer made of gas and an olefin resin composition such as polyester film such as paper, aluminum foil, foam sheet, myler, or the like. It can manufacture by adhering by means, such as a method.

The metal material constituting the container lid body may be, for example, a light steel plate such as aluminum, or a coated steel plate such as tin plated steel sheet, or electrolytic chromic acid treated steel sheet (tinplysyl), and these metal materials are well known per se. It may be coated with a protective paint, for example epoxy-phenolic paint.

Molding of the coated metal plate into the shell body can be easily performed by means of draw processing, deep draw processing, draw ironing processing, press molding, and the like. Adhesion of the liner in the container lid body can be easily performed with an adhesive coating layer containing, for example, polyethylene oxide or acid-modified olefin resin.

In the present invention, the container lid shell may of course be molded of plastic.

The present invention is applied to any container lid in which the opening of the container lid is performed by relative rotation between the lid and the container, for example, a screw cap, a filter proof cap, a lag cap, a press-on twist-off cap ( It can be used as a press-on twist-off cap, a twist crown, etc., and the sealing to be fastened to the container diameter of the container lid can be performed on a roll-on (threaded by a thread roller), a press-on, a screw-on, etc. This can be done by.

The invention is illustrated by the following example.

Example 1

After roll coating 70 parts by weight of epoxy resin, 10 parts by weight of urea resin, 20 parts by weight of polyethylene oxide, and an adhesive paint made of an organic solvent on an aluminum plate having a thickness of 0.25 mm, the plate was heated at 200 ° C. for 10 minutes. It was. Next, the cap shell is press-molded so that the coated surface is inward. The obtained cap shell is heated to about 150 ° C. with a high frequency heating apparatus, extruded thermoplastic resins of various formulations shown in Table 1 from the extruder, and the applied resin is introduced into the cap shell with a rotary blade, and immediately pressed to press the liner part cap. Was written. The weight of the liner resin at this time is 0.5 g, and the shape of the molded liner shape and the cap shell are shown in FIGS. 2 and 3.

100 cc of carbonated beverages (gas capacity 4 gas) are filled in the glass container which has the filled content which has the bottle opening part joined with this cap, and it seals with the said various caps about one week after manufacture. Within 2 hours after sealing again, vibration was performed under conditions of an acceleration of 1 G, an amplitude of 3 mm, and each of 30 minutes in length and width to make a test filling bottle, and the following evaluation was performed. About 24 charge

Subsequently, 50 panelists judged the difficulty of individuality with respect to the various samples which hold | maintained for 1 month in the said environment. The ease of opening was evaluated according to the easy opening rate. Moreover, the liquid leak rate was calculated | required about the various samples which were preserve | saved inverted for 1 month in the said environment.

) 디엔중합체(SIS)가 적으면 충전직후의 개전토오크가 낮기 때문에, 1G의 비교적 심하지 않은 진동이라도 내용액의 누설을 일으키고, 이 중합체가 30%까지만 되면 벌써 개전이 불가능하게 된다. 또 활제의 첨가량은 너무 과다하면 직후의 개전토오크가 낮고 진동으로 누설된다. 또한 본 실험에 사용한 활제는 LDPE단체의 동마찰계수(動摩擦係數) 0.55에 대하여 0.1% 함유한 LDPE의 동마찰계수를 0.21로 하는 효과를 가지고 있었다.Table 1 shows the results of the above experiment. As a result, the cap according to the present invention was particularly good in practical characteristics such as opening and sealing properties. On the other hand, the extremely low EPDM is inferior in sealing property, and the extremely large is difficult to open, and the shape of the liner is not sufficiently released and the sealing is also bad. Next pore volume (

) When the diene polymer (SIS) is small, the opening torque immediately after filling is low, and even a relatively insignificant vibration of 1 G causes leakage of the contents, and when the polymer reaches 30%, the opening is already impossible. If the amount of the lubricant is too high, the opening torque immediately after it is low and leaks due to vibration. In addition, the lubricant used in this experiment had the effect of setting the coefficient of kinetic friction of LDPE to 0.11 with respect to 0.55 of kinetic coefficient of LDPE alone to 0.21.

TABLE 1

LDPE: Low Density Polyethylene (MI = 8.5, Density = 0.918, Crystallinity 60%)

EPDM: ethylene propylene diene copolymer (propylene 28 wt% (hereinafter expressed as wt%) crystallinity less than 5%)

SIS: styrene isoprene styrene block copolymer (isoprene content 62%, styrene part molecular weight 30,000, isoprene part molecular weight 16,000)

L ₁ : Oleic acid amide

Example 2

The names of various constituent materials of the liner agent of Table 2 are shown. The component ratio of the crystalline polyolefin and the low crystalline (or amorphous) polyolefin in the base resin (A) is 80 parts by weight and 20 parts by weight, respectively, and the addition amount of the conjugated diene copolymer and the lubricant is based on the base resin (A). 7 wt% and 0.5 wt%, respectively.

A sheet having a thickness of 0.5 mm was formed from a uniformly dispersed mixed resin having such a composition.

The carbonated beverage water was filled in the same manner as in Example 1, and the opening torque value (average value of the sample water 20) was measured over time after being closed with the various caps. The results are shown in Table 2.

As a result, the present invention has good electrical conductivity in all of them, and in particular, an ethylene-propylene (or butene-1) copolymer and a block having a range of copolymerization ratios among low crystalline (or amorphous) components in the base resin component. Coupling of the copolymer had the most practical performance. In addition, the kinetic friction coefficients of the lubricants L ₂ and L ₃ used in this test were measured in the same manner as in Example 1, and the results were 0.32 and 0.01, respectively.

TABLE 2

Note) HC-LC: HC and LC are crystalline polyolefin and low crystalline or amorphous, respectively.

EB: ethylene-butene-1 copolymer The copolymer ratio and crystallinity are as follows.

EB ₁ : Butene-1 5.4 wt% Crystallinity 57%

EB ₂ : Butene-1 11.5 wt% Crystallinity 10.5%

EB ₃ : Butene-1 21.6wt% Crystallinity less than 5%

EP: Ethylene-propylene copolymer The copolymerization ratio and crystallinity are as follows.

EP ₁ : Propylene 4.8wt% Crystallinity 62%

EP ₂ : Propylene 15.2wt% Crystallinity 18%

EP ₃ : 27.4 wt% propylene crystallinity less than 5%

EP ₄ : Propylene 45.0 wt% Crystallinity 0%

EVA: Crystalline degree of 5% or less of ethylene (80) -vinyl acetate (20) copolymer

EV: 15% ethylene-acrylic acid copolymer crystallinity

LDPE: Low Density Polyethylene (MI = 4.5, Density = 0.921 Crystallinity 68%)

SBS: Styrene Butadiene Styrene Block Copolymer (Cariflex TR1102)

SIS: styrene isoprene styrene block copolymer (Cariflex TR1107)

NR: natural rubber (pale crepe # 1)

BR: cis-1,4-polybutadiene rubber

SBR: Styrene Butadiene copolymer rubber (Styrene 25wt%)

L ₂ : lauric acid ethylene bisamide

L ₃ : erucic acid amide

Claims (1)

0.001 to 5% by weight of lubricant and base resin, based on 95 to 30% by weight of crystalline polyolefin and 5 to 70% by weight of low crystalline or amorphous copolymer of ethylene and other olefins. A container lid with an openable liner, characterized in that it comprises a liner made of a composition comprising a polymer containing 1 to 15% by weight of conjugated diene in an amount of 10 to 30% by weight.

Images