JPS5841050A - Method of preventing breakdown and scattering of glass vessel - 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 The present invention relates to a method for preventing glass containers from breaking and scattering by coating the glass containers with a uniaxially stretched film of a specific sterene-butadiene-butadiene copolymer.

Because glass containers are transparent, the contents can be clearly seen, and they have excellent chemical resistance, solvent resistance, and weather resistance. Glass containers are also relatively easy to make into various shapes, so they have been used for storing liquid substances since ancient times. Initially, they were used in a wide range of applications as containers for various substances. However, due to the nature of the material used for glass containers, they are susceptible to impact and are relatively easily damaged when dropped or hit, and are generally brittle and prone to repeated damage due to sudden changes in temperature.

Particularly in the case of glass bottles that contain carbonated beverages and have internal pressure, as in the case of glass bottles, sudden shaking of the bottle or sudden changes in the temperature of the bottle can increase distortion of the bottle.

Alternatively, the bottle may burst due to a sudden increase in internal pressure. In this case, the glass shards caused by the explosion will fly in all directions, causing damage to people and property.

Also, in the case of a glass bottle containing a large amount of contents,
Since the L shape is heavier, it is easier to drop it, and in that case there is a high risk of the bottle breaking, and if it breaks, pieces of the cigar will be scattered in all directions.

As described above, glass containers are easily broken and shattered due to their fragility, which is dangerous, so various methods for preventing them from being shattered and shattered have been proposed. among them.

A relatively effective method is JP-A-48-2801.
4.

It is disclosed in JP-A-48-34919, % JP-A-48-69681, etc. There is a method of coating a glass container with a conjugated diolefin-monovinyl-substituted aromatic compound block copolymer, and more recently, a method of using a block copolymer glue, 9K SDR latex, has also been practiced. However, since '&-, coating glass containers has the disadvantage that not only is the process complex, but the coating is difficult to remove when the glass container is reused.

The present inventor has conducted extensive research into the technology of preserving glass containers through shrink coating, but found that polyvinyl chloride film, which has traditionally been widely used as a shrink film, has poor %Sakai temperature characteristics, so it cannot be used at low temperatures. Prevention of destruction and scattering′
It was dangerous if the effect was sufficient.

The present inventor further investigated the coating properties of various materials on glass containers and the effect of preventing breakage and scattering. As a result, it was discovered that by using an l-axis stretched film of a specific styrene-butadiene four-dimensional copolymer, it was possible to obtain a coating that had excellent coating properties on glass containers and was also excellent in preventing fractures and scattering. Completed the invention.

That is, in the present invention, the weight ratio of styrene and butadiene is 1.
Using an l-axis stretched film of a styrene-butadiene block copolymer with a ratio of 80:4G to 95:5 and a styrene block having a number average molecular weight of 1aOGO to FHE000, the #l-axis stretched film was heat-shrinked in a glass container. This is a method for preventing glass containers from breaking and scattering, which is characterized by coating them.

The present invention will be explained in detail below.

The styrene-butadiene block copolymer used in the present invention is a block copolymer having at least one, preferably two or more, styrene blocks and at least one butadiene block.

Here, the butadiene block refers to a polybutadiene block or a butadiene block containing 50% by weight or more, preferably 70% by weight.
It is a polymer block containing 0 weight or more, more preferably 90 weight or more, and the copolymerized monomer that this polymer block may contain is styrene/.

Inoprene etc. can be opened. When the butadiene block is a copolymer, the copolymerized monomers may be uniformly distributed in one polymer block, or may be distributed in a tapered (gradually decreasing) manner.

The weight ratio of styrene and butadiene in the block copolymer used in the present invention is 60:4G to 95:5, preferably To: 30 to 90:10, more preferably t.
i, ts: 2s to B5: 15, which is a preferable range and has an excellent balance between the rigidity of the film and the effect of preventing fracture and scattering.

The number average molecular weight d of the styrene block of the block copolymer used in the present invention is 1G, Goo to 000, preferably 100 to 5aooo, more preferably 200 to 5 pseudoOOO, and the number average If the molecular weight is less than 10.000, the film strength will be low and the effect of preventing fracture and scattering will be reduced.
The axial stretchability is insufficient and the heat-shrinkable coating becomes J) Ic<.

It is effective for the block copolymer used in the present invention to have a non-blocking ratio expressed by the following formula of 11% or less, preferably 10- or less, more preferably 59G or less, in order to improve the rigidity of the film. , depending on the purpose, 15
It is also possible to use one or more.

The weight of the styrene block in the block copolymer is Jt.

A method of oxidative decomposition of a copolymer with di-tert-butyl hydroperoxide using osmium tetroxide as a catalyst (for example, L, M, KOLTHOFF, eta
l, , J, Polym, Set, 1.421
(1946) 'method described in K.').

The block copolymer used in the present invention can basically be produced by conventionally known methods, such as those disclosed in Japanese Patent Publication No. 36-19286, Japanese Patent Publication No. 43-149711, Japanese Patent Publication No. 4@
-36957, Japanese Patent Publication No. 48-2423, Seiban W348-4106, etc. can be used, but the number average molecular weight and styrene content of the styrene block are within the range specified in the present invention. It is dangerous if manufacturing conditions are not set so that All of the above-mentioned known methods involve block copolymerization of styrene and butadiene using a 7-ion polymerization initiator such as an organolithium compound in a hydrocarbon solvent, and the general structural formula is (A-g)n-.・・・-1--・・・・・・(A) AfB
-A)n・-・・・・・・・・・・(B)B+A-B)
n-...-...(c) (In the above formula, A is a styrene block, and B is a polymer block mainly composed of butadiene. The boundary between the A block and B block is not necessarily There is no need for a clear distinction. Also, n is 1
is an integer greater than or equal to ), or a linear block copolymer represented by the general structural formula %) () () (In the above formula, A and B are the same as above, and X is, for example, silicon tetrachloride, tin tetrachloride, etc. (wherein m and n are integers of 1 or more. In the present invention, the block copolymer may be a mixture of push copolymers having the above structure.

The number average molecule of the butadiene block of the block copolymer used in the present invention is not limited as long as other restrictions are met, but it is preferably from SOO to 10QOOO. In addition, the number average molecular weight of the block copolymer itself is 20
．． Goo to 5o to 000 is preferred.

In the present invention, the preferred block copolymer has a styrene content of 70-90% by weight, n in the general structural formula (a) is 3 or 4, ←) n is 2 or 3 in K, n in (c) is 2 to 4, n in (c) is 2 or 3 and m is 1 to 3, n in (c) is 2 or 3゛ and m
is 1 or 3, (e) trap n is 1 or 3 and m is 1
The melt flow (200C, SKF weighting) measured according to JIS SK-6870K ranges from 0 to 50P/10 min. Such a block copolymer is not a bittern that can be produced relatively easily, and has excellent film formability and stretching properties, and the l-axis stretched film thereof has excellent covering properties for glass containers and an excellent effect of preventing breakage and scattering.

The block copolymer used in the present invention may be modified by water bulk addition, halogenation, hydrogen halogenation, epoxidation, or chemical reaction within a range that does not impair its basic properties, such as drawing properties and rigidity. Modifications such as introduction of functional groups such as hydroxyl groups, thiol groups, nitrile groups, sulfonic acid groups, carboxyl groups, and amino groups may be performed.

Various additives can be added to the block copolymer used in the present invention depending on the purpose. Suitable additives include low molecular weight polystyrene, coumaron, etc.
Softeners and plasticizers such as indene resin, terpene resin, and oil can be used. Further, various stabilizers, pigments, antiblocking agents, antistatic agents, lubricants, etc. can also be added. In addition, examples of anti-blocking agents include fatty acid amide, ethylene bisstearate, sorbitan monostearate,
Saturated fatty acid esters of aliphatic alcohols and pentaerythritol fatty acid esters are preferably used.

Conventionally, as a method for obtaining l-axis stretched film from the above block copolymer, polystyrene, polyvinyl chloride, etc.
Although the method of stretching to form a film may be applied as is, transverse uniaxial stretching using a tenter is preferable in consideration of productivity and the possibility of forming the film into a shape for later coating on glass containers.

In the present invention, the exfoliation temperature is 60 to 150°C, preferably 70 to 130°C, more preferably 8° to 1
It is preferable to carry out substantial El axis stretching at 20° C. at a stretching ratio of 1.5 to 8 times, preferably 2 to 6 times. The uniaxially processed film of the block copolymer of the present invention has a heat shrinkage rate of 15 inches or more at 100°C in the stretching direction, preferably 20 inches.
90 inches, more preferably 40 to 80 inches, and a tensile modulus of 7. Goo K4/cA or higher, preferably hx
(b) oo Kg/- or more, more preferably 15 COO
K9/- or higher. In addition, in the present invention, substantially 1
Axial stretching means uniaxial stretching so that the heat shrinkage rate at 80°C in the direction orthogonal to the stretching direction is less than 15 inches, preferably less than 10 inches, and more preferably less than 5 inches. do.

In 1@stretching of the above block copolymer, the stretching temperature was 6
If the temperature is less than 0°C, breakage will occur during stretching, making it difficult to obtain the desired stretched film, and if it exceeds 150°C, it will be difficult to obtain a film with good shrinkability. It is selected within the above range to correspond to the stretching ratio, but is the stretching ratio less than 1.5 times? In this case, the heat shrinkage rate is small and it becomes difficult to coat a glass container due to the heat shrinkability, and a stretching ratio exceeding 8 times is not preferable for stable production in the stretching process. Furthermore, if the heat shrinkage rate at 100tllC is less than is-, the shrinkage is poor, so there is a core wall that kills and evenly stabilizes the process in the coating process, and if the temperature in the core process is uneven, This causes a problem of uneven shrinkage due to non-uniform shrinkage.

Furthermore, when the tensile modulus is less than 7ρoob/-,
When covering a glass container with a uniaxially stretched film, the film is weak and sag, making it impossible to cover the glass container in a fixed position.

In the present invention, the heat shrinkage rate at 100°C means that the uniaxially stretched film is heated to 10% (1°C hot water, silicone oil,
The heat shrinkage rate in the stretching direction when immersed in a heat medium such as glycerin for 5 minutes is 15 when actually heat shrinking the block copolymer l-axis stretched film of the present invention.
From a few seconds to a few minutes at a temperature of 0 to 250 C, e.g. 2 to 60 C.
It may be heat-shrinked by heating for seconds.

In order to cover a glass container with the 1# stretched film of the present invention, first the 111+ stretched film is stretched into a tube in the transverse direction, and then a total tube is placed over the glass container and heated from the outside of the tube to shrink the glass container. You can take a method of bringing it into close contact with the In this case, it is often necessary to cover the entire surface of the glass container, and usually the sides of the glass container are mainly covered, and if necessary, even a part of the bottom is covered, so that the total surface area is covered by at least 6G squares, preferably at least 80 cm. The object of the invention is achieved, and depending on the case, only the parts that are particularly susceptible to destruction and scattering may be avoided.

When forming a l# processed film into a tube, it is necessary to bond the films together, and any bonding method such as heat sealing, bonding with an adhesive, or a solvent can be employed. Furthermore, it is possible to cut the Kl-axis stretched film into a predetermined length before making it into a tube and make it into tubes one by one, but in terms of productivity, it is better to cut the long film into a predetermined width first. Continuously tubed,
A method in which the material is then cut into a predetermined length is preferable.

The length of the tube of uniaxially stretched film to cover the glass container should be 105% -2001G with respect to the longest outer circumference of each cross section of the glass container,
If it is shorter than 106 inches, it will not be covered, and if it is longer than 200 inches, not only will the uniformity of heat shrinkage be lost, but the position will likely shift.

The shape of the glass container that is the object of the present invention is not particularly limited, but in general, a glass container with a circular cross section or a shape close to it is suitable. However, there are only four shapes whose cross sections are similar to triangles, quadrilaterals, etc.

The method of the present invention is effective not only for pressurized type containers such as beer and carbonated drinks, but also for glass containers for all purposes, and is effective for glass containers with thick walls to prevent bottles from breaking. The wall thickness can be reduced and weight reduction can also be avoided.

Further, the method of the present invention is easy to cover and remove, and is particularly effective for containers that are reused many times.

Furthermore, the uniaxially stretched film of the present invention is essentially transparent, and is not only ideal for applications that require the retention of contents, but can also be used as a label if printed on the film in advance. It can also serve as a.

Examples of the present invention are shown below, but these are intended to explain the present invention in more detail and are not intended to limit the present invention.

Examples 1 to 3, Comparative Examples 1 to 2 Polymer structure, styrene content, and molecular weight of polystyrene block were 11 g As shown in Table 1, the castyrene-butadiene block copolymer was normalized in Φ-san using n-butyllithium as an initiator. It was polymerized as Next, these Prusk copolymers were formed into a sheet using a 50 mm diameter extruder, and the ridge tenter was used to stretch the sheet in the lateral force direction for 3.
A film stretched 5 times was prepared. The thickness of the film was approximately 80 tones.

In addition, stretching i11 degrees starts from a state where the temperature of the film is 140 degrees Celsius, and lowers the temperature by 10 degrees Celsius.
The lowest temperature at which stretching was possible at a stretching speed of lo %/see was determined, and that temperature was taken as the stretching temperature.The properties of the obtained nine-five-axis stretched film are also shown in Table 1. Table 1 *i: s represents a polystyrene block, and B represents a polybutadiene block. The same applies to the table below.

*2: Immerse it in a silicone bath at 100℃ for a few seconds,
It was calculated using the following formula. The same applies to the table below.

t: Length before shrinkage t': Length after shrinkage The uniaxially stretched film shown in Table 1 was
m.

It was cut into a length of 306 nm and made into a tube with a length of 260 nm and a diameter of 9 (7) using adhesive. This tube has a height of 30
A general LT glass container with a maximum diameter of 8 m1 and the top is narrower, covered with a 110°C oven Vc
It was placed for 1 minute to heat shrink. At that time, the position of the film was set so as to cover the bottom of the container approximately 13 times from the outer periphery after heat shrinkage.

Effect of preventing glass containers from breaking and scattering: A film-covered glass container containing the contents is dropped horizontally from the height of ICT651 onto concrete, and the amount of the glass container remaining inside the diameter tm is measured. It was determined by

The above experiment was conducted on the l-axis stretched film trap shown in Table 1, and the results are shown in Table 2.

Group 2 table Example 4 ~ @, Comparative example s-4 #! Same as Example 1. The styrene-butadiene four-block copolymer shown in Table 3 was polymerized and subjected to the same procedures as in the examples, from sheet formation to glass container drop test.

However, for the block copolymers and polystyrene of Example 6 and Comparative Example 4, the polymerization solvent was cyclohexane. The results are shown in Table 3. Example 1, Comparative Example 5 8-B9L1 was polymerized in cyclohexane using n-butyllithium as an initiator, and then 81C1 was polymerized as a coupling agent. A radial type styrene-butadiene block copolymer was produced by ring reaction.Similarly, 5-B-8 and (S-B) were reacted in Schiff nitrogen hexane using n-butyllithium as an initiator. -S
Of these block copolymers, some styrene was taper copolymerized to the butadiene block of 5-B-8. These block copolymers were stretched using a tenter in the same manner as in Example 1 to form a film with a width of 70 mm. This film was cut into a length of 24 mm lengthwise and 24 mm wide using an adhesive. , into a tube with a diameter of 7 cya. This tube has a height of 20m and a maximum diameter of 6mm,
It was placed over a typical glass container for carbonated beverages with #1 on the top and heat-shrinked in the same manner as in Example 1.The glass container drop test was conducted under the same conditions as in Example 1.
(Voluntary action to amend procedures for keeping carbonated beverages at 20℃ and 5℃) November 7, 1980 Director General of the Patent Office Shima 1) Haruki Tono 1, Indication of the case Patent Application No. 18114 of 1978
01 No. 2 Name of the invention Method for preventing glass containers from breaking and scattering a Relationship with the case of the person making the amendment Patent applicant 1-2-6 Dojimahama, Kita-ku, Osaka-shi, Osaka (OOa)
Teru Miyazaki, Representative Director and President of Asahi Kasei Industries, Ltd. 5. Contents of amendment (1) # The scope of claims is amended as shown in the attached sheet.

(2) "Styrene-butadiene block copolymer" on page 6, line gxs-17 of the specification is corrected to the following sentence.

“Styrene-butadiene block copolymer Garana 9 has a heat shrinkage rate of 15° C. or more in the stretching direction and a tensile modulus of r, ooo Kg/cpA or more.” (3) Same page 9. r(A-B)n in lines 17-19, -...Song/Song 0)A%B-A)
n・・・・・・−・・・・・・・・・(b)B+A-B)
,・・・・・・・・・・・・(c)'' to r(S-B
)11. −・Song times・・Song・0) S+B−8) 1m−One song・・（B）B + S −B To song−・−・・−
・(c)" and correct it.

(4) On page 9, the addition “mu” is corrected to rSJ.

(5) rS 7' for “A pay” on the second line of the 10th member.
"t-tsuku," he corrected.

(6) r ((B -A)n-)7-X-゛°track°track subject) in the same No. 1O, lines 7-9
(A-B - Uyo,, -X...-...
(E) ((B -A+-B Utomi 4.-X...
...(to) '' rlB-8)fi→, -7x-...
・−・−・・・・(d) [: (8-B ), −)
i, 1-X-・-・・・・・・・(E)((B −8+
B iX・・・・・・・・・(to)((8-B-)-
8iX...----()) Correct J.

(7) On page 10, line 10 of the same page, replace [%A, B in the above formula with 8. B corrects it as].

(8) “n in (c)” on page 11, lines 7-8
is 2 or 3" is changed to "(d) and (e) where n is 2
Or 3,” he corrected.

(9) Change “(d)” to “(e)” on page 11, line 8 of the same page.
I am corrected.

(7) Replace “(e)” on page 11, line 9 with r ()) J
I am corrected.

L The weight ratio of styrene and butadiene is so: 4G
~SS: S and the number average molecular weight of the styrene block is IQ, @6@e~7a06. A glass container characterized in that the uniaxially stretched styrene film is coated with heat shrinkage to trap the glass container. Method 2 for preventing fracture and scattering 2 A method for preventing fracture and scattering according to claim 1, wherein the styrene-butadiene block copolymer has two or more styrene blocks. % Formula % (1 (In the above formula, S is a styrene block, B is a butadiene block, and X is a residue of a coupling agent or a residue of a polymerization initiator of a polyfunctional organolithium compound.) The method for preventing fracture and scattering according to claim 1, in which the styrene block has a number average molecular weight of 1 (000 to 6,000) & The weight ratio of styrene and butadiene is 70: so
〜■;1O 4 A method for preventing destruction and scattering according to claim 1, in which the weight ratio of styrene and butadiene is 5:25 to s
s: 15, method 7 for preventing fracture and scattering according to claim 1, wherein the uniaxially stretched film is a tenter transversely uniaxially stretched film & axial stretching according to claim 1. The film is stretched at a temperature of 60°C to 150°C.
, stretching ratio 1. 1. A method for preventing fracture and scattering according to claim 1, which is a film substantially uniaxially stretched at a ratio of S to 3 times. Thermal shrinkage rate is less than ls%, and the transverse tensile modulus is 1 (LOOOKg/
C11 or higher, method 1α for preventing fracture and scattering according to claim 1. A method IL for preventing fracture and scattering according to claim 1, in which the uniaxially stretched film is formed into a tube in the stretched transverse direction. The method for preventing fracture and scattering according to claim 1, wherein the shrink coating is performed by covering a glass container with a tube-shaped uniaxially stretched film and bonding it tightly by heat shrinking.

Claims (1)

[Claims] L The weight ratio of styrene and butadiene is go: 4e
~ Guo: s, and the number average molecular weight of the styrene block is 1
A glass container characterized in that a glass container is coated with a heat-shrinkable oriented film using an IA stem V-butadiene block copolymer 0 in Tsuru・OO to 7 Tsuru・OO. Method for preventing fracture and scattering 2 Method for preventing fracture and scattering according to claim 1, wherein the styrene-butadiene splitter copolymer has two or more styrene blocks & Styrene-butadiene block copolymer is generally used Formula % Formula % (1 (In the above formula, M is a styrene block, B is a butadiene block, and represents a residue of a coupling agent from Company X or a polymerization initiator 0!I group of a polyfunctional organic lithium compound). ) A method for preventing fracture and scattering according to claim 1, wherein the number average molecular weight of the styrene block is 1
4,000 to 6,000, the method for preventing destruction and scattering according to claim 1, wherein the weight ratio of styrene and butadiene is 0: SO~
The method for preventing fracture and scattering according to claim 1, wherein the weight ratio of styrene and butadiene is 110:10.
7. A method for preventing fracture and scattering according to claim 1, where as: Is. 7. A method for preventing fracture and scattering according to claim 1, in which the uniaxially stretched film is a tenter horizontal uniaxially stretched film. However, the stretching temperature is 6o~150℃
A method for preventing fracture scattering according to claim 1, wherein the film is substantially Kl-axially stretched at a stretching ratio of 1.5 to 8 times. Above, the tensile modulus is 7,0ooKf/c
Method 1 for preventing fracture and scattering according to claim 1, which has a heat shrinkage rate of 40 to 90% in the transverse direction at 100° C. and a heat shrinkage rate in the longitudinal direction at 100° C.
5-, and the tensile modulus in the transverse direction is 10,000
Kf/- or more, the fracture scattering prevention method IL according to claim 1. The fracture scattering prevention method 12 according to claim 1, wherein the l-axis stretched film is a film formed into a tube in the stretched transverse direction. , The method for preventing fracture and scattering according to claim 1, wherein the heat-shrinkable coating is performed by covering a glass container with a tubular l-axis stretched film and bringing it into close contact with the glass container by heat-shrinking.