JP2534282B2 - Synthetic paper suitable for tape - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a synthetic paper suitable for the taste of green tea.

[Prior Art] As a synthetic paper for conventional tagging, the first layer having a heat-sealing property made of hemp pulp, wood pulp and polyolefin fibers, and the heat-sealing property made of hemp pulp, wood pulp and rayon fibers have not been used. The laminated paper having the second layer, the paper obtained by further heat-treating the laminated paper, or the paper disclosed in JP-A-59-228100, that is, made of polyester fiber and having heat sealability. A synthetic paper comprising a first layer, a fiber having a low melting point component in at least a part thereof and a polyester fiber (hereinafter referred to as an ester fiber), and a second layer having no heat-sealing property, which are laminated and integrated. , Both the first layer and the second layer are low-oriented polyester fibers (hereinafter PET
Synthetic paper that contains more than 30% of binder).

[Problems to be solved by the invention] Of these, the taobag paper is usually used for barley tea, but even if a small bag made of such paper is filled with green tea and hot water is poured into it, the tea component eluted is the taobag. Adsorbed on the hemp pulp and wood pulp of the paper, the flavor peculiar to green tea is almost lost. Not only that, although such papers contain polyolefin and rayon fibers, no suitable binder fibers are used, so the papers after papermaking are extremely weak and unusable. Therefore, in reality, despite the high cost, the paper once obtained is heat-treated to melt the polyolefin resin in the first layer.
There is no choice but to use a method of adhering them to improve paper strength.

Further, the taobag paper is a compound fiber paper containing ester fiber as a main component and does not adsorb the taste component of green tea, but like the taobag paper, no suitable binder fiber is used, and Since the ester fiber, which easily shrinks at high temperatures of 160 ° C or higher, is used as the main fiber, the strength of the paper after papermaking is weak.
When heat-sealed at 0 ° C or higher, the shrinkage is large, and the molded bag is deformed, which has the drawback that the commercial value is significantly impaired. Further, by heat-treating such paper, the strength can be improved and the shrinkage at the time of heat sealing can be improved, but the process becomes complicated and the cost becomes very high, and when the low melting point component is polyethylene terephthalate,
It has a drawback that crystallization progresses during heat treatment and the heat sealability is lost.

The present invention eliminates such problems, does not adsorb the components of green tea when used as a green tea flavoring paper, has sufficient strength to be used just by making paper, and heat during bag making. It is an object of the present invention to provide a synthetic paper suitable for a tape bag which has almost no shrinkage due to a seal and is excellent in heat sealability.

[Means for Solving the Problems] The present invention is a two-layer laminated paper having a first layer of 200 ° C.
A copolymerized polyester fibrous binder having a compounding fiber having a shrinkage of 10% or less (hereinafter referred to as a low shrinking fiber) of 5% by weight or more, a melting point of 110 to 230 ° C. and a birefringence (hereinafter referred to as Δn) of 0.035 or less ( Hereinafter referred to as Co-PES binder) 10 ~
80% by weight, the second layer is 5% by weight or more of low-shrinkage fiber, the melting point is 240 to 270 ° C, Δn is 0.020 or less, and the intrinsic viscosity is
Polyethylene terephthalate fibrous binder of 0.50 to 0.58 (hereinafter referred to as low [η] PET binder) 10 to 80
It is a synthetic paper suitable for a taobag characterized by containing it in a weight percentage.

The synthetic paper of the present invention does not substantially absorb the components of green tea because it does not substantially contain a cellulose-based pulp substance having self-adhesiveness such as wood pulp or hemp pulp,
It has a Co-PES binder in the first layer and a low [η] PET binder in the second layer, and these binders adhere to each other when dried during paper making, so they have sufficient strength to withstand use without heat treatment. Since the main fiber is low shrinkage fiber, it does not shrink even when the paper is rapidly heated by heat sealing, and the first layer uses a Co-PES binder having a melting point of 110 to 230 ° C. When the layers are folded in two so that they are in contact with each other and heat-sealed, they firmly adhere and the heat-sealed part does not peel off even when boiled, and a low melting point [η] PET binder is used as the binder for the second layer. Since it does not stick to the sealer surface in heat sealing, since the binder of such synthetic paper is made of polyester polymer, it does not break even if the obtained bag is boiled. Not only the substances that form the paper but also the paper do not elute, and it is a very excellent synthetic paper. Such excellent synthetic papers are obtained only by combining the above components.

The low-shrinkage fiber used in the present invention is 1
It is a compound fiber having a shrinkage rate of 10% or less, which is used as a main fiber in both the first and second layers of the synthetic paper of the present invention, and heat sealed at a temperature of 160 ° C. or higher. It acts to suppress contraction. Mixed paper amount is first
Both the layer and the second layer are 5% by weight or more, preferably 30 to
When the mixed papermaking amount is less than 5% by weight, the amount of the fibers is small, so that shrinkage occurs during heat sealing, and the formed tape bag is deformed. As such a fiber, vinylon fiber, rayon fiber, acrylic fiber, polyamide fiber, ester fiber or the like is appropriately heat-treated to have a shrinkage ratio of 10% or less under the above conditions.
Of course, two or more kinds of these fibers may be mixed and used.
The fineness of this low shrink fiber is 0.1-4.0 denier and the fiber length is 1
-25 mm is preferred.

The Co-PES binder is used in the first layer of the synthetic paper of the present invention, and acts as a binder in the drying treatment in paper making,
When the temperature for drying is 150 ° C. or lower, it has self-adhesiveness during heat sealing. Such a binder is a non-stretched product, a semi-stretched product, a high-speed spinning product or the like obtained by a usual ester fiber production process using a copolyester, and has a melting point of 110 to 230 ° C, preferably 130 to 220 ° C, Δn.
Is 0.035 or less, preferably 0.030 or less, the fineness is 0.
The fiber length is preferably 1 to 4.0 denier and the fiber length is 1 to 25 mm. Melting point
If the temperature is lower than 110 ° C, the heat-sealed portion may come off during the immersion of the tea bag in hot water. If the temperature is higher than 230 ° C, the heat-sealing property of the obtained paper becomes poor. When Δn exceeds 0.035, not only the heat-sealing property of the obtained paper becomes poor but also the strength becomes weak. The copolyester used is a dicarboxylic acid other than terephthalic acid such as isophthalic acid, adipic acid or sebacic acid, or an ethylene glycol such as diethylene glycol, propylene glycol, neopentyl glycol or tetramethylene glycol, as the acid component and / or diol component of polyethylene terephthalate. It is substituted with a diol other than. The mixing amount of such a binder is 10 to 80% by weight, preferably 30 to 60% by weight of the first layer. If the amount of mixed paper is less than 10% by weight, the heat-sealing property becomes poor and the strength decreases, and if it exceeds 80% by weight, shrinkage at the time of heat-sealing becomes large.

The low [η] PET binder is used in the second layer of the synthetic paper of the present invention, and acts as a binder in the drying treatment in papermaking, but it does not stick to the sealer surface when it is heat-sealed. There is. Such a binder has a melting point of 240 to 270 ° C and an intrinsic viscosity of 0.50 after being made into fibers.
.About.0.58, preferably 0.52 to 0.56, of polyethylene terephthalate, and .DELTA.n is 0.020 or less, preferably 0.015.
It is the following. The fineness is preferably 0.1 to 4.0 denier and the fiber length is 1 to 25 mm. If the melting point is less than 240 ° C, it will stick to the sealer during heat sealing, and if it exceeds 270 ° C, the strength will be weakened. When [η] is less than 0.50, the fiber-forming property is poor, and when it exceeds 0.58, the binder property is insufficient and the strength of the resulting synthetic paper is weakened.

In addition to the above fibers and binders, ordinary papermaking ester fibers, nylon fibers, polyolefin fibers, wood pulp, hemp pulp and the like may be mixed in each of the first and second layers. However, since natural pulp such as wood pulp has a drawback of impairing the flavor of green tea, it is preferable not to exceed 20% by weight. Furthermore, these fibers and pulps must be those which do not significantly impair the above-mentioned features of the present invention.

The synthetic paper of the present invention is a laminated paper mainly composed of low shrinkage fibers, and the basis weight of such paper is preferably 8 to 30 g / m ² , and the basis weight ratio of the first layer and the second layer is 3: 7 to 7: 3 is preferable.

The synthetic paper of the present invention can be easily produced by a usual paper machine capable of making paper. The paper making net used may be a cylinder or a short net, and the dryer is preferably a Yankee type, but may be a multi-cylinder type or a through type.

The dry heat shrinkage ratio in the present invention is obtained by placing the main fiber on a hot plate at 200 ° C. for 1 minute and then cooling it in the atmosphere for 15 minutes, and measuring the fiber length before and after the hot plate treatment. It was calculated in.

The shrinkage rate during heat sealing is 100 m in width when folded in two so that the first layers of 160 mm wide strip-shaped synthetic paper are in contact with each other.
m, length 15 mm, surface temperature 170 ℃, sandwiched between two metal plates, crimped at a pressure of 10 kg / cm ² for 0.5 seconds, the length before and after crimping was measured, and calculated by the following formula Is.

Regarding the flavor of the tea extract, the taste extract filled with 1 g of sencha was dipped in 100 ml of hot water at 90 ° C. for 90 seconds, the extract obtained was contained in a small amount in the mouth, and the taste was examined for sensory evaluation.

The method of measuring [η] and Δn in the present invention is as follows.

[Η]: Polyethylene terephthalate fiber is dissolved in a solvent mixture of equal weight of phenol and tetrachloroethane,
It was measured at.

Δn: It was calculated by calculating the retardation from the Berek compensator method using a sodium light source lamp using a polarizing microscope manufactured by Nippon Kogaku.

The present invention will be described in more detail with reference to the following examples. The% shown in the examples is a value based on weight unless otherwise specified.

Examples 1 and 2 and Comparative Examples 1 to 3 A first layer was obtained by a viscose method using an ordinary paper-making machine consisting of short-mesh and a Yankee-type dryer having a surface temperature of 130 ° C. It has a dry heat shrinkage of 3.2%, a denier of 1.5, 5 mm of rayon fiber of 50%, and a polyethylene terephthalate copolymer obtained by replacing 25 mol% of terephthalic acid with isophthalic acid.
Polyethylene terephthalate with n of 0.006, 2 denier and 5 mm of Co-PES binder of 5 mm and having [η] of 0.54 after the second layer was made of fiber was used.
0.014, 1.0 denier, 5mm low [η] PET binder 50
%, And the basis weight ratio of the first layer and the second layer is 1: 1 and the basis weight of the laminated paper formed by both layers is 20.1 g / m ² (Example 1). Paper was made.

According to the method of Example 1, the rayon fibers of the first and second layers were replaced with a dry heat shrinkage of 5.0% and a degree of formalization of 28.0%.
Then, using a vinylon fiber of 0.5 denier and 3 mm, a baking paper (Example 2) having a basis weight of the combined paper of 20.4 g / m ² was produced.

In the method of Example 1, instead of rayon for the first layer and the second layer, a normal papermaking ester fiber made of polyethylene terephthalate having a dry heat shrinkage of 18.5%, 0.5 denier and 5 mm was used. A taobag paper (Comparative Example 1) having a basis weight of 20.2 g / m ² was made.

According to the method of Example 1, polyethylene terephthalate having a melting point of 255 ° C. and a fiber [η] of 0.62 after being formed into a fiber was used in place of the low [η] PET binder of the second layer, and Δn was 0.08, 1.
Using an ester binder of 0 denier 5 mm, a paper making paper (Comparative Example 2) having a basis weight of 19.9 g / m ² was made.

Using the paper machine of Example 1, the first layer consisted of 30% CSF430 ml hemp pulp, CSF550 ml NBKP 30%, 2 denier, 5 mm polypropylene fiber 50% and the second layer 50 g of the hemp pulp.
%, The NBKP 30%, and the rayon fiber 20% used in Example 1, the basis weight ratio of the first layer and the second layer is 1: 1, and the papermaking amount of such a laminated paper is 20.1 g / m ² Of the taobag paper of
Further, it was heat-treated in a hot air oven at 200 ° C. for 20 seconds (Comparative Example 3).

 The results are shown in Table 1.

[Effects of the Invention] As described above, the synthetic paper of the present invention is extremely important not to impair the flavor of the contents such as green tea and barley tea required for the taobag paper while ensuring the handling properties such as paper strength and heat sealability. Satisfying various characteristics. Furthermore, it is inexpensive because it does not require post-processing after papermaking, and it is not only used for green tea, barley tea, black tea, but also various types of soup stock such as bonito, etc., that is, a disposable used for hot water extraction. Can be widely used in bags.

Claims (1)

(57) [Claims] 1. A two-layer laminated paper having a first layer of 200 ° C.
10% to 80% by weight of a copolyester fibrous binder having a shrinkage rate of 10% or less and a compounding fiber content of 5% by weight or more, a melting point of 110 to 230 ° C. and a birefringence of 0.035 or less.
Polyethylene terephthalate fibrous binder having a shrinkage at 200 ° C. of 10% or less, 5% by weight or more, a melting point of 240 to 270 ° C., a birefringence of 0.020 or less, and an intrinsic viscosity of 0.50 to 0.58. 80% by weight synthetic paper suitable for taobags.