JPS5993632A - Cup and its manufacture - 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 paper cup for carbonated beverages. Conventionally, wax-impregnated paper cups have been mainly used as paper cups for carbonated beverages. In other words, wax-impregnated paper cups are made by punching base paper and forming the cup, and then impregnating the base paper with a certain amount of wax by spraying melted paraffin (wax) at 200 to 250 °C at a spray rate of 1/-. The purpose of this paper is to improve the water resistance and strength of the base paper, but the problem is that (1) the bending suitability is not as good as that of polyethylene coated paper cups.

■Poor manufacturing efficiency.

■The manufacturing process is complicated.

Improvements were desired.

On the other hand, when attempting to fill a carbonated beverage such as cola into a polyethylene coated paper cup that is normally filled with hot contents such as coffee or tea, significant foaming occurs during filling and the cup overflows.

Polyethylene coated paper cups were considered unsuitable as carbonated beverage cups.

The present invention aims to improve these problems.It has bending suitability, manufacturing yield, and manufacturing efficiency comparable to ordinary polyethylene coated paper cups, and has the same or lower bending properties as wax-impregnated paper cups when filling carbonated beverages. This invention provides a cuff made of paper coated with polyolefin resin that has the property of suppressing the foaming property of π, and is an extremely novel invention that takes economic efficiency into account.

The present invention will be explained in detail below.

First of all, what are the factors that can cause foaming when carbonated drinks are poured into a cup?
(b) Contact angle between the material of the inner surface of the cup and the liquid content (c) Smoothness of the inner surface of the cup) Shape of the cup (e) Temperature of the carbonated beverage solution to be filled, etc. List some factors.

As a result of intensive research conducted by the present inventor, it was found that the biggest causes of foaming in polyolefin resin-coated cups are the contact angle between the inner surface layer of the cup and the content liquid, and the temperature of the filled carbonated beverage solution. did.

That is, as shown in FIG. 1(a), the inner surface of the cup (
When the contact angle (θ) between the material 1) and the content solution (2) f, that is, the carbonated beverage, is large, the foaming property is large, and the contact angle increases as shown in Figure 1 (b) K. It was found that when the value of (C)) is small, the foamability is small, and the effects of the wettability index of the material of the inner surface il+, the smoothness of the inner surface of the cup, and the shape of the cup are relatively small.

On the other hand, there is a large difference in foamability depending on the temperature of the carbonated beverage solution, with the temperature being between 9 and 10℃, the foamability is low when the temperature is below J1, and the foamability is low when the temperature exceeds 10℃. was found to increase.

However, since the temperature of the carbonated beverage solution is normally controlled to be 9'C or less by a bending machine, it can be excluded from the target factor.

Therefore, by discovering a material structure that reduces the area of the contact angle (t), it is possible to obtain a paper cup for a polyolefin resin coated bending machine that exhibits low foaming properties when filled with carbonated beverages.

In view of this actual result, the present inventors have determined that the polyolefin resin may deteriorate or decompose on the surface of the polyolefin resin layer.
It has been discovered that by applying a rinsing treatment, the value of the contact angle can be reduced and the effervescence of the carbonated beverage can be kept to a small level.

The following will explain the embodiment shown in the drawings. Fig. 2 shows a partially cutaway cross-sectional view of the present invention's adjustable cup (A) θ), and shows the paper layer (4) of the cup wood (3). On the inside, there is no degradation of the polyolefin resin on the surface layer. A polyolefin resin layer (5) is formed which has been subjected to a roughening treatment.

As the polyolefin resin used in the present invention, any resin that can be normally used for extrusion coating may be used.
Any of these can be used, and the present invention is not limited to the first one. Specifically, polyethylene, polypropylene, ethylene-vinyl acetate copolymer resin, copolymer resin of acrylic or methacrylic acid and olefin, or α-olefin or ethylene having 6 to 12 carbon atoms.
Examples include α-olefin copolymer resin. Furthermore, the effect can be further enhanced by adding extender pigments such as clay, bentonite, kaolin, and talc, and white pigments such as titanium oxide to these polyolefin resins for the purpose of reducing the contact angle.

Next, in the present invention, the treatment for preventing the deterioration or decomposition of the polyolefin resin means using the following method.

That is, as is well known, polyolefins such as polyethylene and polypropylene are sprayed with an acetylene-oxygen flame using the IIIK gas flame spray method.
0,1707,174sl-') as the main body, RR
'=CH2(88Bcrn-'), RCH=CH2
(909cm-'), RCH=CHI￥(965G
111"'), RCOOR' (1175, 1240
ENT-+)--c-o(iooo, 1065.1075.
1o 90cx-'), ROOM(35,', 8.3
(SO3c7rL-'), ROH (3626,36
It is known that special infrared spectrum absorption can be seen in 68CTL'''1). Therefore, when a gas flame is sprayed onto ml of polyolefin resin layer,
Due to oxidative deterioration, hydrophilic groups such as carbonyl groups and hydroxyl groups increase.

Similarly, as a method of irradiating ultraviolet S, 254.31
It is known that carbonyl groups are generated when a polyolefin resin is irradiated with an ultraviolet light source with a dominant wavelength of 6.360 or 380 mμ, and even by radiation irradiation, a significant increase in hydroxyl groups and carbonyl groups appears on the surface of the polyolefin resin. Increase in hydrophilic groups.

Also, by corona discharge treatment, hydrophilic groups such as hydroxyl groups, carbonyl groups/, and c are similarly increased on the surface of the polyolefin resin.

Sarahi is a polyolefin resin surface? :: Due to mechanical abrasion, the molecular arrangement becomes disordered, the degree of crystallinity decreases, the abrasion ivc polar groups increase, and the hydrophilicity increases.

In this way, a treatment that accelerates the deterioration or decomposition of a polyolefin resin is a process in which a part of the surface of the polyolefin resin is degraded by a gas flame spray method, an ultraviolet irradiation method, a radiation irradiation method, a corona discharge treatment method, a mechanical abrasion method, etc. Alternatively, by decomposition, hydrophilic groups such as hydroxyl groups or carbonyl groups are increased on the surface of the polyolefin resin, and the hydrophilicity of the surface is improved, and the contact angle between the surface of the polyolefin resin and the liquid content is reduced. ) It's amazing.

The inventor's experiments revealed that these polyolefin resins deteriorated or decreased! By adjusting the amount of treatment so that the contact angle between the burnt polyolefin resin layer and water is 400C or less in the atmosphere, the carbonated beverage can be filled with wax-impregnated paper cups. It has been discovered that it is possible to obtain a cup made of filter paper that has a foaming property of 30% or less.

Next, as a cup manufacturing method, a base paper is extruded and coated with a polyolefin resin, and then the surface of the polyolefin resin is subjected to a treatment to cause deterioration or decomposition of the polyolefin resin, and then a cup is molded.

The present invention provides a cup having the above-mentioned structure and a method for controlling the desire therefor, which includes: improving the hydrophilicity of the surface of the polyolefin resin;
This cup improves wetting with carbonated beverages, reduces the contact angle (θ) value, and has appropriate foaming properties for carbonated beverages, and can be used as is on the production line for regular polyethylene coated and paper cups. To provide a cup with excellent bending suitability without reducing work efficiency.

Specific examples will be shown below.

〔Example〕

Cup base paper (manufactured by Shiba Paper Co., Ltd.) having a basis weight of 245 g/m' was coated with polyolefin resin by extrusion using an extruder, and the thickness of the resin layer was uniformly 20 μm.

Furthermore, the surface of the coated polyolefin resin was subjected to various treatments to promote deterioration or decomposition of the polyolefin resin to obtain cup base paper for each example.

Next, using the cup base paper treated as described above, a 9-ounce cup was formed using a cup forming machine manufactured by MC (USA).

1 m of liquid after molding 5” Carbonated drinking water (Coca-Cola)
was injected into each cup at an injection speed of 200 m and 176 seconds, and the foaming properties were compared and confirmed.

Table 1 shows the results in a list. The 9-ounce cup molded from cup base paper (C), which has the structure of the present invention, has the conventional structure (polyolefin resin single layer product) K.
In comparison, the foaming property when injecting carbonated drinks is the minimum required,
It was extremely good. The criteria for determining foaming properties are as follows.

Table-1

[Brief explanation of the drawing]

FIGS. 1(a) and (b) are explanatory diagrams showing the contact angle (θ) between the material of the inner surface of the cup and the content solution, and FIG. 2 is a partially enlarged front view showing one embodiment of the cup of the present invention. It is a diagram. Prisoner...Cup il+...Cup inner surface (2)・
... Contents solution (3) ... Cup body (4) ...
Paper layer (5)... Modified polyolefin layer Patent applicant Toppan Printing Co., Ltd. Figure 1 1

Claims (2)

[Claims] (1) By forming a polyolefin resin layer on the inner surface of the main body of a paper cup and subjecting the surface of the polyolefin resin layer to a treatment that promotes deterioration or decomposition, the surface of the polyolefin resin layer and water can be bonded to each other in the atmosphere. Contact angle wo4
A cup characterized by TK of 0° or more. (2) Forming a polyolefin resin layer on the vagina by extrusion coating or other means, and then subjecting the surface of the vaginal polyolefin resin layer to a treatment that promotes deterioration or decomposition 1-. , and then molding using an f-cup molding machine.