JP3535010B2 - Bread-making plastic container and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic bread-making plastic container, and more particularly, it is possible to put bread-making dough into a baking container and store the bread-making dough in a frozen state. The present invention relates to a plastic container for bread and a manufacturing method thereof. INDUSTRIAL APPLICABILITY The plastic container for bread making of the present invention is suitable as a so-called baked bread making container in which the dough for bread making is stored in a frozen state and thawed, fermented and baked at the time of use.

[0002]

Bread is obtained by baking (roasting) a dough prepared by mixing wheat and rye flour as a main ingredient with water and a puffing agent and kneading the mixture. BACKGROUND ART Bread has conventionally been manufactured through the steps of kneading raw materials, dough fermentation, finishing (dividing, rolling, intermediate roasting, shaping or molding) and baking. In recent years, frozen dough has been developed as a material for improving the preservability of bread dough. The frozen dough is one in which the bread dough can be stored in a frozen state, and can be thawed, fermented and baked at the time of use.

Due to the recent boom in gourmet food, the demand for warm fresh bread is increasing. If a predetermined amount of frozen dough is put in a container and stored in a frozen state, and if it can be thawed, fermented and baked while being put in the container at the time of use, freshly baked bread can be easily provided. Containers used for such applications have heat resistance that does not melt, decompose or deform even under high-temperature firing conditions,
It is required to have various properties such as cold resistance (cold impact resistance) that does not easily break even under low-temperature freezing conditions, durability that can be repeatedly used, and light weight that is convenient for handling and transportation. Further, since the bread is baked into the shape of a container, the bread-making container is required to have excellent shape retention of the container and release of the bread from the container.

Conventionally, an aluminum tray (hereinafter abbreviated as an aluminum tray) has been used as such a bread-making container. Aluminum tray has excellent heat resistance and cold resistance,
Reusable and lightweight. However, the aluminum tray has the following problems. (1) The aluminum tray as a whole is susceptible to deformation and has a difficulty in shape retention. Also, the aluminum tray is partially
It is easy to get dents and requires careful handling. (2) Aluminum trays can be wrinkled during manufacture,
Since the bread dough enters the wrinkles, it is difficult to separate the mold when taking out the bread after baking, and there is a problem in workability. In addition, burns during firing tend to adhere to the wrinkles on the aluminum tray. To obtain releasability, it is necessary to apply a large amount of oil to the inner surface of the aluminum tray each time. (3) Although the aluminum tray can be used repeatedly, in reality, the prototype is damaged by deformation or dent during use, and therefore the number of times of repeated use cannot be increased so much. Further, recent medical information points out the relationship between aluminum and Alzheimer's disease, and there is a problem that aluminum trays are not suitable for repeated firing.

As described above, the aluminum tray has problems in shape retention, releasability, workability, reusability and the like. Therefore, it is desired to use a heat-resistant plastic container that can replace the aluminum tray. BACKGROUND ART Conventionally, as a heat-resistant plastic container that can endure a firing process, for example, a container made of crystallized polyethylene terephthalate resin (hereinafter abbreviated as C-PET) is known. C-PET containers can withstand heating up to 220 ° C.

However, when the C-PET tray is used as a bread container, the baking temperature of the bread is 20.
Repeated firing at around 0 ℃, subject to thermal deformation,
The number of repeated uses cannot be increased. Some types of bread are baked at a high temperature exceeding 220 ° C., but the C-PET tray is not suitable for the production of bread that requires baking conditions at such a high temperature. Furthermore, the C-PET tray has insufficient cold shock resistance, and for example, it contains -35 in a frozen dough for bread making.
When it is rapidly frozen at a temperature of ℃ or less, or when it is stored or transported at a temperature of -18 ° C or less, it is easily damaged by various impacts. If the crystallinity of the C-PET tray is increased, the cold shock resistance can be improved to some extent, but the heat resistance is lowered. Therefore, the C-PET tray is unsatisfactory as a bread-making container for business use that requires a high degree of cold resistance, heat resistance, and reusability.
However, conventionally, it has been difficult to develop a plastic container excellent in heat resistance and cold shock resistance, which replaces the C-PET container.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bread-making plastic container in which a bread-making dough can be put and baked repeatedly. Further, the object of the present invention, from the storage, freezing, storage, transportation of frozen dough for bread making, through the steps of thawing, fermentation, baking, all steps of the production of freshly baked bread, can be repeatedly used. To provide a plastic container for bread. Another object of the present invention is to provide a method for manufacturing such a plastic container for bread making.

As a result of intensive studies to overcome the above-mentioned problems of the prior art, the present inventors have found that poly-1,4-cyclohexylene dimethylene terephthalate / isophthalate resin has an intrinsic viscosity of 0.75 dl. / G or more of the amorphous sheet was prepared, and then, when thermoforming this amorphous sheet, the molding conditions were adjusted to create a container having a resin density within a specific range. It has been found that it has a high degree of heat resistance that can be achieved and a cold shock resistance that does not easily break even under freezing conditions, and that it has excellent shape retention and mold release properties and is suitable as a bread-making container.

The bread-making plastic container of the present invention does not have a risk of being deformed or dented, has a heat resistance of 250 ° C. and a temperature of -40.
It has cold shock resistance in the range of ℃ to -35 ℃, can be repeatedly baked 30 times or more, and has good mold releasability after baking. Further, the plastic container for bread making of the present invention does not have a food hygiene problem such as eluate, is excellent in aroma retention, and has little discoloration during heating. Further, when the plastic container for bread making of the present invention is used, the baking time can be significantly shortened. The present invention has been completed based on these findings.

[0010]

According to the present invention, a poly-
1,4-cyclohexylene dimethylene terephthalate
Intrinsic viscosity of isophthalate resin is 0.75dl /
The density obtained by thermoforming an amorphous sheet of g or more is 1.2.
A plastic container for baking of 015 to 1.2120 g / cm ³ is provided. Further, according to the present invention, a poly-1,4-cyclohexylene dimethylene terephthalate / isophthalate resin having an intrinsic viscosity of 0.85 dl / g or more is melt-extruded into a sheet to obtain an intrinsic viscosity of 0.75 dl / g.
The above-mentioned amorphous sheet is prepared, and then the amorphous sheet is thermoformed into a container shape to have a density of 1.2015 to 1.2120.
There is provided a method for producing a plastic container for bread making, which comprises producing a container of g / cm ³ .

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Poly-1,4-used in the present invention
Cyclohexylene dimethylene terephthalate / isophthalate resin (hereinafter abbreviated as PCTA resin) is 1,4-
It is a thermoplastic saturated copolyester resin obtainable by polycondensation of cyclohexanedimethanol with terephthalic acid and isophthalic acid. Terephthalic acid and isophthalic acid can also be used as alkyl esters such as dimethyl terephthalate and dimethyl isophthalate, respectively. The molar ratio of the terephthalic acid component and the isophthalic acid component can be appropriately determined if desired, but is usually 9
9.9: 0.1 to 50:50, preferably 99: 1 to
It is about 70:30.

The intrinsic viscosity (IV) of PCTA resin is 0.
Although it is about 7 to 1.3 dl / g, in the present invention, it is usually
0.85-1.3 dl / g, preferably 0.90-1.
2 dl / g, more preferably 0.95 to 1.1 dl / g
PCTA resin of. If the intrinsic viscosity of the PCTA resin to be used is too low, the intrinsic viscosity of the obtained amorphous sheet decreases due to the reduction of the intrinsic viscosity in the manufacturing process of the amorphous sheet by melt extrusion, and by extension, the thermoforming of the amorphous sheet. The heat resistance and cold resistance of the container obtained by the above method are deteriorated. P
The CTA resin is usually produced by a solid phase polymerization method and supplied as pellets in a crystallized state. The density of the pellets is about 1.2150 g / cm ³ .

As the PCTA resin used in the present invention,
Commercially available products can be used, but as an example, KODAR THERM X676 manufactured by Eastman Chemical Company, USA
1) A copolyester resin can be mentioned. This copolyester resin is approved by the US FDA for use as a food container material, details of which are provided in the US Federal Government CFR21 subpart § 177.1240. The Polyolefin Council of Japan has approved the use of the copolyester resin as a material having food hygiene safety in accordance with the voluntary regulation standard (Positive List).

The plastic container for bread of the present invention is made of P
Although it can be obtained by thermoforming an amorphous sheet made of CTA resin, the density of the obtained container is controlled to 1.2015 to 1.2120 by controlling the molding conditions during thermoforming.
It is necessary to adjust it within the range of g / cm ³ . When pellets of PCTA resin are fed to an extruder and melt-extruded to form a sheet, a substantially amorphous sheet (amorphous sheet) is obtained. Here, “substantially amorphous” means that the crystallinity is usually 6% or less (corresponding to a density of 1.1966 g / cm ³ ),
In most cases, the degree of crystallinity is 5% (density 1.1959 g / c
m ³ ) or less. When the amorphous sheet is thermoformed (vacuum forming, pressure forming, etc.), the crystallinity can be increased. Since the density is proportional to the crystallinity, the higher the crystallinity, the higher the density.

When the density (crystallinity) of the container obtained by thermoforming an amorphous sheet of PCTA resin is low, the heat resistance is insufficient, and when heated to a high temperature of 250 ° C., the container is easily deformed. . On the other hand, if the density of the container is increased, a container excellent in heat resistance can be obtained, but cold shock resistance is lowered, and for example, the container is easily damaged in a drop test at a low temperature of -40 ° C to -35 ° C. To do. However, in thermoforming an amorphous sheet made of PCTA resin, it is difficult to stably obtain a container having a desired density. That is, even if the amorphous sheet is thermoformed under normal conditions, it is difficult to obtain a container having a desired density, and the density distribution is not uniform.

Therefore, the inventors of the present invention added 1.2015 to 1.212 by adding an appropriate crystal nucleating agent to the PCTA resin or controlling the crystallization treatment conditions during thermoforming.
When a container having a density in a very limited range of 0 g / cm ³ (corresponding to a crystallinity of 13 to 28%) was manufactured, heat resistance (heat resistant rigidity) that withstands heating at 250 ° C.
It has been found that a heat-resistant / cold-resistant container having a cold shock resistance capable of withstanding a drop test under a low temperature of 40 ° C to -35 ° C can be obtained. The density of the container of the present invention is preferably 1.2.
029 to 1.2099 g / cm ³ (crystallinity 15 to 25
%), And more preferably 1.2036 to 1.2085 (crystallinity 16 to 23%). When the density of the container made of PCTA resin is within the above range, high heat resistance and cold shock resistance can be balanced.

To manufacture the container of the present invention, first, PC
A mixture is prepared by adding a crystal nucleating agent and, if necessary, an additive such as a colorant and an antioxidant to the crystallized pellets of the TA resin. As the crystal nucleating agent, inorganic particles, organic particles and the like can be used, but inorganic particles such as calcium carbonate are preferable from the viewpoint of easily adjusting the density of the container within a desired range. The compounding ratio of the crystal nucleating agent is usually 0.01 to 5 parts by weight, preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the PCTA resin.

When coloring the container of the present invention, a heat-resistant inorganic pigment or organic pigment can be added as a colorant. The PCTA resin originally has a light candy color, but when it is heated at a high temperature as a container, it changes to a dark brown color, so it is preferable to add an antioxidant. As the antioxidant, a phenolic antioxidant is preferable. An appropriate amount of these additives is blended, if necessary. Additives are selected and used for their safety in food hygiene.

Next, an amorphous sheet is produced by supplying a mixture of crystallized pellets of PCTA resin with a crystal nucleating agent and the like to an extruder and melt-extruding it into a sheet.
In order to obtain a container with uniform density and excellent heat resistance and cold shock resistance, it is important to obtain a uniform extruded sheet with good thickness accuracy and little decrease in the intrinsic viscosity of PCTA resin in this melt extrusion process. Is. As a result of investigations, the present inventors have found that when the amorphous sheet obtained by the melt extrusion step has an intrinsic viscosity of 0.75 dl / g or more, the amorphous sheet is thermoformed together with the density requirement. It has been found that the heat resistance and cold shock resistance of the obtained container are highly balanced, and a container satisfying various properties required for a plastic container for bread making can be obtained.

When a twin-screw co-directional vacuum degassing (venting) extruder is used as an extruder and melt extrusion is performed from a T-die, an amorphous sheet in which a decrease in intrinsic viscosity is suppressed within 10% is obtained. It is preferable above. When a twin-screw co-direction / vacuum degassing extruder is used, even if the hydrolyzable PCTA resin pellets are melt-extruded without being dried in advance, the decrease in intrinsic viscosity can be sufficiently suppressed. If the decrease in the intrinsic viscosity of the amorphous sheet obtained by the extrusion step is too large, the cold impact resistance of the obtained container will decrease. The intrinsic viscosity of the amorphous sheet is preferably 0.75 to 1.1 dl / g. A method of previously drying the PCTA resin pellets with a dehumidifying / drying device can also be adopted, but it is economically disadvantageous because of high equipment cost and operating cost. The thickness of the amorphous sheet obtained by the extrusion step is usually 0.2 to 2.0 mm, preferably 0.3 to
Although it is 1.5 mm, it is not limited to this range.

The amorphous sheet of PCTA resin is formed into a container by thermoforming such as pressure forming or vacuum forming. In thermoforming, molding conditions such as the temperature of a heating mold and a cooling mold are controlled in order to precisely adjust the density of the obtained container to fall within the above-mentioned limited range. As a thermoforming method, there is a two-step method in which an amorphous sheet is preheated with a heater, thermoformed in a heating die, and then transferred to a cooling die. In the two-stage method, for example, a heating die equipped with a pressure air vacuum forming machine and a temperature control device and a cooling die are arranged in series, and an amorphous sheet preheated by a heater is supplied,
The first stage is 150 to 200 ° C., preferably 160 to 200 ° C.
It is shaped into a container in a heating mold whose temperature is controlled to 190 ° C, more preferably 165 to 180 ° C, and then, as a second stage, 10 to 60 ° C, preferably 20 to 50 ° C, more preferably 30. It is transferred to a cooling mold whose temperature is controlled at -40 ° C and molded. In each mold, the sheet is thermoformed into the shape of a container by compressed air and vacuum pressure. In the heating mold,
Crystallization is promoted, and in a cooling mold, excessive crystallization is suppressed. As a result, a container having a uniform and desired density can be obtained.

In the above two-step method, the cost of the mold is high and the molding cycle is long, so it is difficult to reduce the cost. Therefore, as a simpler molding method, it is preferable to adopt a one-step method using only a heating mold whose temperature is precisely controlled.
In the one-step method, thermoforming and crystallization are performed simultaneously in a heating mold. In the one-stage method, for example, an amorphous sheet preheated by a heating heater is supplied to a heating mold equipped with a pressure air vacuum forming machine and a temperature control device, and a container is placed in the heating mold whose temperature is controlled to 165 to 175 ° C. And at the same time suppress the crystallization by compressed air cooling to obtain a container having a uniform and desired density. In this molding method, it is preferable to control the surface temperature of the mold within a predetermined temperature ± 3 ° C.

The shape and size of the container of the present invention are not particularly limited, but it is usually preferable to set it in the shape of a tray and match it with the shape of the bread obtained after baking. However, it is also possible to make containers of various shapes according to the desired bread shape. FIG. 1 shows an example of the plastic container for bread of the present invention. FIG. 1 shows a state in which bread-making dough is put into a tray-shaped plastic container for bread-making 1 and baked to form a freshly baked bread 2. A curved surface or a convex portion for adjusting the shape of the bread may be provided on the side surface of the tray, and a gas vent hole may be provided at the bottom portion.

The bread-making plastic container of the present invention can be used in a commercial oven or a microwave oven at 250 ° C. for 15 minutes.
Even if heated for a minute, it does not deform and there is little discoloration,
There is no eluate and it has practically sufficient heat resistance. Therefore, the plastic container for bread making of the present invention is 10 to 2 at 170 to 230 ° C. which is a normal baking condition of bread.
It can sufficiently withstand heating for 5 minutes and can be repeatedly fired 30 times or more. The bread plastic container of the present invention has rigidity, and thus has excellent shape retention,
Does not deform or dent like an aluminum tray. The bread-making plastic container of the present invention does not wrinkle like an aluminum tray, and therefore has good mold releasability of the bread, and can be easily released without applying oil such as salad oil, No burnt deposits during firing. Even when oil is applied, the amount of application and the number of times of application can be reduced. It was found that the baking time can be shortened by about 20 to 30% by using the plastic container for bread making of the present invention as compared with the case of using the aluminum tray.

The plastic container for bread making of the present invention does not break even in a drop test at a low temperature of -40 ° C to -35 ° C and has sufficient cold shock resistance. Therefore, the plastic container for bread making of the present invention is filled with the dough for bread making (normal temperature) and quick frozen (-40 ° C to -35).
℃), packaging / transportation / storage (-18 ℃ or less), thawing (room temperature to 25 ℃), fermentation (for example, temperature 36 ℃, relative humidity 80%), baking (170-230 ℃, 10-25 minutes)
It can withstand such processes and usage cycles.

Therefore, the plastic container for bread making of the present invention is suitable as a so-called baked bread making container in which the bread making dough is stored in a frozen state and is thawed, fermented and baked at the time of use. is there. Of course, the use form of the bread-making plastic container of the present invention is not limited to the above-mentioned one, and for example, a usual bread-making dough (raw dough) can be put and baked. The type of bread can also be applied to various things such as butter roll, croissant, and bread.

[0027]

EXAMPLES The present invention will be described more specifically below with reference to Examples and Comparative Examples. The methods for measuring the physical properties are as follows. (1) Intrinsic viscosity (IV) According to Eastman Chemical Method. Average value of 10 measurements. (2) Density According to ASTM D1505. Average value of 10 measurements. Shimadzu SGM-220G- is used for density measurement.
An 01 type specific gravity measuring instrument was used. A test piece of a certain size was taken from the container or sheet, and the density of each was measured. (3) Crystal melting temperature (Tm) According to ASTM D3418. Average value of 10 measurements. (4) Heat resistance (heat deformation during baking) The container was filled with bread dough at room temperature, and then the container was placed in an oven whose internal temperature was adjusted to 220 ° C.
It was heated and baked for 0 minutes. After the heating was completed, the degree of deformation of the taken-out container was observed, and those without deformation were evaluated as pass (◯), and those with deformation were evaluated as fail (x).

(5) Cold impact resistance (falling impact strength) A container filled with frozen dough for baking was put in a freezer whose interior was adjusted to -35 ° C and stored for 24 hours. The container was taken out from the freezer and immediately dropped from a height of 1 m onto a concrete floor to observe the presence or absence of damage and the state thereof. If all of the 10 measurements were not damaged, it was judged as acceptable (○), and if there was a dent, there was a problem (△).
Even if one piece was damaged, it was evaluated as rejected (x). (6) Baking Pan Releasability After baking, the freshly baked bread was taken out from the container, and the ease of taking out the bread was evaluated. The case where the bread was easily taken out was judged as good (○), the case where it was difficult to take out a little, but the case where the bread was not attached to the container was judged as slightly good (△), and the case where it was difficult to take out was judged as poor (x). . (7) Necessity of Oil Application In order to obtain the releasability of the baked bread, the case where the application of salad oil was not required was evaluated as pass (◯), and the case where it was necessary was evaluated as fail (x).

Example 1 <Preparation of Tray> Crystallized pellets (IV = 0.960 dl / g, density = 1.2) of PCTA resin (produced by Eastman Chemical Co., trade name PCME6761).
A mixed masterbatch (manufactured by Eastman Chemical Co., trade name P-2950) containing a crystal nucleating agent, a coloring agent, and an antioxidant at 150 g / cm ³ and Tm = 285 ° C.
A) was mixed at a ratio of 40: 1 (weight ratio), and then the mixture was supplied to a twin-screw co-direction / vacuum degassing extruder and melt-extruded from a T-die to form an amorphous material having a thickness of 0.5 mm. Created a sheet. This amorphous sheet (density = 1.1935 g / c
m ³ ; intrinsic viscosity = 0.85 dl / g) was supplied to a forming machine in which a heating die and a cooling die equipped with a pressure air vacuum forming machine and a temperature control device were arranged, and an amorphous sheet preheated by a heating heater Was thermoformed into the shape of a tray in a heating die of 170 ° C., and then transferred to a cooling die of 35 ° C. to obtain a tray (length 80 mm × width 140 mm × height 50 mm). The density of the obtained trays is 1.250 g / c on average.
m was ³ (crystallinity 18%). This tray holds 25
No deformation even if placed in an oven at 0 ° C for 15 minutes,
Even when frozen at a low temperature of 40 ° C. for 24 hours, the impact strength was practically satisfactory.

<Manufacture of Bread for Baking> A frozen dough for baking of butter rolls was prepared by the following method according to the following method. Medium seed flour 58 parts by weight egg 9 parts by weight yeast 4 parts by weight water 23 parts by weight Kneaded wheat flour 42 parts by weight sugar 2 parts by weight skim milk powder 6 parts by weight oil 11 parts by weight yeast 2 parts by weight water 17 parts by weight guar gum 2 parts by weight The seeds were agitated and mixed, and fermented in about 2.5 hours. Next, this kneading was prepared by stirring and mixing components other than oil and fat for about 6 minutes, then adding oil and fat and mixing for about 6 minutes. Then
The dough was divided into about 45 g and molded by a crescent molder to prepare bread dough for butter roll.

<Steps from Freezing to Baking> The frozen dough for bread making as described above was put in the tray made above and put in a freezer at −35 ° C. and stored for 24 hours. I took the tray out of the freezer and immediately dropped it from a height of 1 m onto the concrete floor,
All of the 10 measurements were not damaged. Place the tray containing the frozen dough for bread making at -18 ° C.
Stored in a freezer for 30 days. There were no changes such as deformation and discoloration in the tray. The tray containing the frozen dough for baking was removed from the freezer and left at 25 ° C. for about 1 hour to return the frozen dough to room temperature. Place the thawed frozen dough for baking in a 36
The yeast was left to stand for about 1 hour under the condition of ° C and relative humidity of 80%. Frozen dough for baking is 3 by fermentation
Swelled about twice. 220 trays containing frozen dough for fermentation
The container was placed in an oven adjusted to ° C and heated for 10 minutes for firing. This baking temperature is slightly higher than the normal baking temperature of the butter roll, but this makes it possible to accurately measure and compare the heat resistance, releasability, and reusability of the tray. The tray of this example had no deformation after firing and had a slight degree of discoloration. After baking, the bread was taken out from the tray. The freshly baked bread could be easily released from the tray of this example, and the tray was free from burnt deposits during baking. The above process was repeated 30 times, but the tray was not deformed, dented, or cracked. The results are shown in Table 1.

[Comparative Example 1] The same procedure as in Example 1 was carried out except that an aluminum tray having the same size and shape as the tray prepared in Example 1 was used. The aluminum tray was cold shock resistant and had dents. Further, the aluminum tray had a poor releasability in the baking pan, and it was necessary to apply salad oil every time in order to obtain the releasability. Further, under firing conditions of 220 ° C. for 10 minutes, squeezed wrinkles on the aluminum tray adhered.
Further, the aluminum tray has a poor shape retention property and is deformed or dented during repeated use, so that the aluminum tray can be repeatedly used only about 10 times. The results are shown in Table 1.

[Comparative Example 2] The procedure of Example 1 was repeated except that the C-PET tray having the same size and shape as the tray prepared in Example 1 was used. The C-PET tray was cold shock resistant and cracked. Also, the C-PET tray is
Under the firing condition of 220 ° C. for 10 minutes, a part of the container was deformed. Further, the C-PET tray was deformed, so that the releasability of the baking pan was somewhat insufficient, and due to insufficient heat resistance and deformation, the C-PET tray could only be used about 5 times. The results are shown in Table 1.

[0034]

[Table 1]

Example 2 The firing temperature of Example 1 (220
(° C) was a little strict as the baking conditions for the butter roll, so the temperature was changed to 200 ° C and the baking time of the bread was examined. As a result, when the tray of Example 1 was used, a freshly baked bread could be obtained in 13 to 15 minutes. On the other hand, when the aluminum tray and the C-PET tray were used, it took 18 to 20 minutes. Therefore, the container of the present invention can contribute to shortening the firing time and energy saving.

[0036]

According to the present invention, there is provided a bread-making plastic container in which a bread-making dough can be put and baked repeatedly. INDUSTRIAL APPLICABILITY The plastic container for bread making of the present invention is excellent in heat resistance, cold shock resistance, shape retention, and mold releasability as a bread making container. The plastic container for bread making of the present invention contains, freezes and stores frozen dough for bread making,
It can be repeatedly used for all the steps of producing fresh breads, including transportation, thawing, fermentation and baking. Therefore, the bread-making plastic container of the present invention has the bread-making dough stored therein in a frozen state,
It is suitable as a container for producing so-called fresh bread, which is thawed, fermented and baked when used. As a matter of course, the plastic container for bread making of the present invention can make bread by putting and baking the bread dough other than the frozen dough. Frozen dough obtained by freezing the dough for bread making after fermentation can also be used.

[Brief description of drawings]

FIG. 1 is a schematic view showing an example of a bread-making plastic container of the present invention.

[Explanation of symbols]

1: Tray 2: baked bread

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References International Publication 97/11106 (WO, A1) International Publication 91/05730 (WO, A1) (58) Fields investigated (Int.Cl. ⁷ , DB name) A21D 8 / 00 C08G 63/00-63/91 C08L 67/00-67/02

Claims (2)

(57) [Claims] 1. A density obtained by thermoforming an amorphous sheet made of poly-1,4-cyclohexylene dimethylene terephthalate / isophthalate resin having an intrinsic viscosity of 0.75 dl / g or more is 1.2015-1. 2120 g / cm ³
Plastic container for bread making. 2. A poly-1,4-cyclohexylene dimethylene terephthalate / isophthalate resin having an intrinsic viscosity of 0.85 dl / g or more is melt extruded into a sheet to obtain an amorphous resin having an intrinsic viscosity of 0.75 dl / g or more. A sheet is prepared, and then the amorphous sheet is thermoformed into a container to have a density of 1.
A method for producing a plastic container for bread making, which comprises producing a container having a weight of 2015 to 1.2120 g / cm ³ .