JPS62273278A - Sealable composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed description of the invention 3. Detailed description of the invention
or water-based latex-type sealing compounds suitable for sealing replaceable or non-replaceable tops. This compound can be used for general sealing purposes, but
It is particularly suitable for sealing containers filled with fatty and oily foods against container distortion.

Traditional water-based latex-type sealing compounds generally consist of styrene-butadiene latex and fillers, thickening resins and other additives. In general, occlusive compounds of this type perform satisfactorily with respect to many types of food products packaged in industry.

However, certain foods that are a problem are those that contain food fats and oils. Oils and fats, such as bean oil, olive oil, etc., tend to swell and deteriorate the seal in the container, which causes vacuum, gas or liquid loss, contaminates the food and induces food poisoning when eaten. Introduce harmful bacteria. It is also detrimental to the shelf life of the product - it is therefore desirable to control the effect on the seal of food oils and fats to prevent food contamination and prolong its stability.

It is an object of the present invention to provide occlusive compounds with improved resistance to attack by food fats and oils.

It is also an object of the present invention to improve the oil resistance of sealing compounds without reducing their sealing properties.

Another object of the invention is to improve the resistance of occlusive compounds to escape into double pairs in the presence of water vapor in the packaging of fatty food products.

It is also an object of the present invention to improve the oiliness of standard water-based styrene ptadiene latex sealing compounds by replacing a portion of the styrene ptadiene latex with polybutadiene latex.

The present invention herein relates to compositions for improving the oil resistance of water-based latex-type occlusive compounds. A novel water-based sealant compound for improving oil resistance comprises a styrene-ptadiene latex, one or more fillers, a thickening resin and other additives, and one of the total latexes.
20 to 30 parts of polybutadiene latex per ooi.

The novel sealing compound of the present invention comprises a water-based styrene-butadiene latex, fillers and other additives, with a portion of the styrene-butadiene latex being substituted with a polybutadiene latex. .

The critical feature of the new sealant compound is the incorporation of polyptadiene latex and its effect on the oiliness of the resulting seal.

An unexpected utility of the present invention is improved oil resistance to food fats and oils. The novel sealant compounds of the present invention seal containers filled with food oils and fats where conventional styrene-butadiene latex sealants are not successful.

A preferred occlusive compound is 1) butanoene latex substituted at about 20 to 30 parts per 100 parts of styrene-ptadiene latex. More polybutadiene latex than 3086 may be used, but the increased effectiveness is
and the overall number of can breaks tends to increase unacceptably. Amounts less than 20 parts can also be used, but the beneficial effect on oil resistance is substantially reduced.

Other preferred embodiments of the novel occlusive compounds of this invention are to use 20 parts of polybutadiene latex per 100 parts of total latex and 80 g of styrene-butadiene latex per 100 parts of total latex. Other ingredients that may be found in preferred embodiments include fillers, thickening resins, stabilizers, bacteriicides, and antioxidants.

Suitable sealing compounds have a total solids content of 50 to 60%, a PI of about 9 to about 10.5, and a Brookfield viscosity of 2000 to 3100 at 760 rpm, and a viscosity of about 30 to about 55%. % oil resistance based on the swelling percentage.

The preferred polybutadiene latex for use in the new occlusive compound polybutadiene latex is a solid rubbery material. The polybutadiene latex preferably has a total solids fi of 50% or more and about 10.5-11.
It has a pH of 8. Examples of polyptadiene latexes suitable for use in the present invention;
& Rubber Co.) Cen-Flo
2000 or Cen-FIo6507. However, any polybutadiene latex that is compatible with the other components of the invention and that forms a good seal can be used.

The styrene-ptadiene latex may be any styrene-ptadiene latex suitable for use in water-based sealing compounds, such as styrene-butadiene rubber melt-polymerized or emulsion-polymerized products. The styrene-butadiene latex used in practice has properties that are sufficiently flexible and elastic to form a good seal;
The choice will be based on compatibility with the polybutadiene latex and other ingredients, and price. Styrene-butadiene latex can be polymerized using any convenient method! ! The leftover latex preferably has about 40-45% total solids and about 10% total solids.
It will have a pH of 5 to about 12.

Water-based sealing compounds One or more commonly used fillers may be added to the compounds of the invention. Preferably the filler is china clay, but curved lead oxide, colloidal silica, microspheres, and the like may also be used. Titanium oxide, carbon black and other such fillers can also be used. The filler should suitably not be abrasive so as not to abrade the machinery that mixes the compound and lines it onto the lid. The filler should also be small in size to avoid liner problems and provide a suitable seal. Preferably the filler is all latex 1
It should be added in a total amount of about 80 to 140 parts per part.

Thickening (B#) is generally incorporated into water-based occlusive compounds and may be included in the present invention. Suitable materials are well known and generally include synthetic hydrocarbon or petroleum resins, polyterpene resins or Generally at least 10 parts of resin should be added per 10 parts of total latex. Preferably about 25 parts per 100 grams of total latex is used.

The novel occlusive compounds may also contain stabilizers to stabilize the two latexes, fillers and other ingredients. The stabilizer can be selected from any material commonly used to stabilize styrene-butadiene latex occlusive compounds. Such stabilizers include, but are not limited to, styrene maleic anhydride, other styrene copolymers, methylcellulose, and casein.

The sealing compounds of the present invention may also contain other ingredients that are normally added to water-based sealing compounds, such as antioxidants such as phenolic antioxidants; bactericidal agents; pH 11!1 moderating agents; It may also contain a small amount of corrosion inhibitor.

The occlusive compounds of the present invention can be prepared by any method conventional to water-based occlusive compounds such as V
! The solid polybutanoene is mixed and ground with fillers and other optional additives, generally including any thickening resin, using an internal mixer such as a Banbury mixer, and water is added to form the polybutadiene. It can be manufactured by making it into latex. The styrene-butadiene latex is prepared separately and the two latexes are then aliquoted in water in the usual manner, for example using a Z-vane mixer. Further ingredients and water may be added to this dispersion.

Instead of mixing the polyptadiene latex and styrene-butadiene latex separately and then dispersing them together, all the latexes and further ingredients may be mixed together before adding the water.

It is also possible to disperse one of the latexes with most of the further ingredients and then add the other latex to this.
Other methods useful in the present invention include U.S. Pat. No. 4,160,7
This is claimed in No. 52. In this method, fillers and other non-plastic components are first suspended in the molten wood Wt component and then emulsified in water;
and finally add the occlusive compound with the latex.
I will build.

The method of making the sealant compound is not critical to the invention as long as it produces a good dispersion that forms a good seal on the container lid when lined.

Further seals made with the occlusive compound of the present invention include:
Formed in any manner conventional for water-based sealants. For example, the sealing surface of a can lid is lined with a sealing compound and dried with air and/or heat to form a seal. The sealing surface is crimped around the edge of the lid, thereby attaching the lid to the sealing surface. If lining a bottle or jar lid, a seal is formed on the top panel, preferably the base of the lid, and a seal is made at the top and lateral edges of the container and at the opening of the lid. Preferably the container is a can, in which case the seal is crimped around the outer periphery of the lid of the container around 7 runs of the outwardly extending side wall and then 7 runs'))-&If1 field L
m A -starvation++ 4 +z +an rw--b
, ny +, - A double seam formed in the conventional manner by pressing against the wall
m) made in

The sealing power of a sealing compound can be determined by various means common in the lidding industry. Two quantitative test methods were used in the following non-limiting examples. This test is (
Referred to as the "biological seal" wipe test and the "swell seal" test, they can be performed as follows.

The lid of the can is lined with a 1-m-2 sealant compound and dried in the conventional manner. The amount of sealant compound is generally such as to provide the recommended dry film capacity for the specially sized lid. The cans with soldered side seams were then filled with the food fat-containing material at a temperature typically of 97° C. and leaving some space at the top. Seam the can with the lid to be tested while injecting water vapor into the headspace.
Outtle! Ieam). The sealed can is typically sterilized at 121°C for 30 minutes (7, Q/4-
The samples were cooled in water containing non-pathogenic microorganisms. After cooling and while still moist, the cans were subjected to controlled deformation at the side seams and double seam junctions. After approximately 6 days of incubation at an elevated temperature optimal for microbial growth and then 1 day of incubation at room temperature, the cans were visually inspected and the number of swollen cans recorded. The remaining cans were tested for their retained vacuum. It is believed that the cans that were held in low vacuum reached a state where the seal failed. The number of bulged and low holding vacuum cans was counted as broken and the biological seal test failure rate was expressed as the number of broken cans per 1000 cans tested. Due to the method used, 1000
The number of failures per piece is significantly higher than would occur in commercially filled cans densified with certain compounds.

Iwap and 62 - ¥! j) Lined over the desensitizing compound and dried in the same manner as described for the biological seal test. Rather than double seam the can, the device was placed at a temperature of approximately 100"F' for 7 days in a veterinarian containing soybean oil. The height of the I%m moisture was measured and the The original height of the sealant was compared. The difference was recorded as a percent of w61.

Biological seal and Bfl seal values as low as possible are desirable as they indicate good densification performance. The following example:
Inclusion of polybutadiene latex generally decreases the test values, thus indicating that an improved seal is obtained over the control compound.

The ve-free compounds in each example were prepared by methods known to those skilled in the art.

In each example, the sealant compound was lined into a can cage, dried, and tested in the manner described.

All quantities are expressed in parts per 100 parts of total latex.

The occlusive compound consisted of: Polybutadiene latex (Gen-Flo 6507) 20
80 parts styrene butadiene latex 80 parts pottery clay 82 parts titanium oxide
8 parts Thickening tree H25 parts Trisodium phosphate 0.2 parts Carbon black 0.15 parts Bactericide 0.13s Antioxidant
t, o part solid stabilizer
0.45 parts densification compound total solids 56.
2%, pH 9.8 and Brookfield viscosity 2400
I had cps.

The failure rate is 290 cans per 1000, and the % of lubrication
was 49%.

For comparison, W, R, Gr. Brace Co., Ltd. (W, R, Gr.
ace & Co, )! A standard water-based styrene-butanoene sealing compound known as WBC-480 for lids was tested. This control occlusive compound was 1000
145 cans were damaged and the swelling was 82%.

Dog [2 A occlusive compound was produced in the same manner as in Example 1, except that 30 parts of polyptadiene latex and 70 parts of styrene-butadiene latex were used. Furthermore, instead of 82 parts of pottery clay, 1 part
20 parts were used. All other quantities and ingredients remained the same.

The resulting sealant had 58% total solids, 11H1o,o, and a Brookfield viscosity of 2500 cps.

325 cans were observed to break and swell by 34%.

Hu1 Drum-1 A sealant similar to Example 2 was prepared except that only 82 parts of pottery clay was used.

The sealant had a total solids of 56.7%, a pH of 9.6, and a Brookfield viscosity of 3050. 3 per 1000
40 cans were broken and 50% swelling was observed.

In addition to the excellent sealing performance of this compound, especially in the presence of fats and oils, the present invention also provides excellent sealing performance when applied to cans.
e) is not affected. 1. Extrusion is a term used in the can industry for the extrusion of a compound into the upper and lower ends of a can or through the opening of the lid. Furnacing is particularly disadvantageous in the case of cans containing fats and oils, which are well known to degrade lining compounds, since it reduces the effective amount of compound in the seam that makes the seal. The loss of compound solder in the seal, such as that caused by evacuation, increases the chance of can breakage and is not acceptable in the industry; furthermore, the extruded material is unsightly and difficult to remove, especially in automated applications. This may interfere with the application of labels, etc. in the line.

The present invention provides an excellent compound for container lids and/or can lids or tops and bottoms by providing improved resistance to attack from oils and fats and from the effects of extrusion.

Although the invention has been described with reference to preferred embodiments thereof, other embodiments may achieve the same results, and changes and modifications of the invention will be apparent to those skilled in the art, and All such modifications and equivalents as come within the true spirit and scope of the invention are intended to be covered by the claims.

Claims (1)

[Claims] 1. A sealing compound comprising styrene-ptadiene latex and polyptadiene latex. 2. The hermetic compound of claim 1, wherein the polybutadiene latex constitutes about 20 to 30 parts per 100 parts of total latex. 3. Filler selected from pottery clay, zinc oxide, colloidal silica, microspheres, titanium oxide, carbon black and mixtures thereof; thickening resin; antioxidant;
The occlusive compound of claim 1 further comprising: and a bactericide. 4. The hermetic compound according to claim 1, further comprising a stabilizer for stabilizing the hermetic compound. 5. The filler is approximately 80 to 14 parts per 100 parts of total latex.
A hermetic compound according to claim 3, comprising 0 parts. 6. The stabilizer is about 0.25 to 100 parts of the total latex.
5. A occlusive compound according to claim 4 comprising about 5.0 parts. 7. Thickening resin is about 10 to 100 parts per 100 parts of total latex.
4. A occlusive compound according to claim 3 comprising about 30 parts. 8. The occlusive compound of claim 1, wherein the occlusive compound has improved resistance to degradation by food fatty oils. 9. The hermetic compound according to claim 1, wherein the styrene-butadiene latex consists of 40% styrene and 60% butadiene. 10. The hermetic compound of claim 1, wherein the polybutadiene latex comprises a solid rubbery polybutadiene material. 11. An occlusive compound comprising about 70-80 parts of styrene-butadiene latex and about 20-30 parts of polybutadiene latex per 100 parts of total latex. 12. A sealing compound for preventing the deterioration of food oils and fats, which comprises styrene-butadiene latex, a thickening resin, and at least one filler, and includes an improvement in which a portion of the styrene-butadiene latex is replaced with polybutadiene latex. 13. The hermeticity of claim 12, wherein the styrene-butadiene latex constitutes about 70 to 80 parts per 100 parts of the total latex of the hermetic compound, and the polybutadiene latex constitutes about 20 to 30 parts per 100 parts of the total latex. Compound. 14. A container having a securely attached closure, the closure having a seal preventing access from the container, the seal being comprised of a compound comprising styrene-butadiene latex and polybutadiene latex. 15. Styrene butadiene latex is all latex 1
15. The container of claim 14, wherein the polybutadiene latex comprises about 20 to 30 parts per 100 parts of total latex. 16. The container according to claim 14, wherein the container is a can, bottle or jar. 17. The container according to claim 14, wherein the lid is the end of a can, the top of a bottle, or the lid of a jar. 18. The container of claim 14, wherein the lid is lined with a seal. 19. Substituting a portion of the styrene-butadiene latex with polybutadiene latex, dispersing the latex to produce a water-based sealing compound, lining the sealing compound on the lid of the container, and lining the sealing compound on the lid. 1. A method for improving the oil resistance of a sealing compound containing styrene-butadiene latex, the method comprising: drying it with water and fixing a lid over a container filled with a material containing food oils and fats. 20. The method of claim 19, wherein polybutadiene latex replaces about 20 to about 30 parts of styrene-butadiene latex per 100 parts of total latex.