JPH0617357A - Table cloth - Google Patents

Abstract

PURPOSE:To obtain a table cloth hard to slip down from the table. CONSTITUTION:The subject table cloth consists of an elastic nonwoven fabric made of fibers composed of a hydrogenated block copolymer C and a polyolefin D. The copolymer C is obtained by hydrogenating a block copolymer having at least 2 polymer blocks A mainly composed of vinyl aromatic compound and at least 2 polymer blocks B mainly composed of conjugated diene compound where at least one polymer block B locates at a chain end of the polymer. The polymerization rate (C/D) of the hydrogenated block polymer C and the polyolefin D is 40/60-99/1.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a tablecloth. More specifically, it relates to a table cloth that does not easily slip off the table when used.

[0002]

2. Description of the Related Art A knitted woven fabric, a non-woven fabric or a film has been widely used as a material for a table cloth.

[0003]

A table cloth made of the above-mentioned material known in the related art has a problem that it is easily slipped from the table with a slight force when it is used. Even though it is known that it is possible to deal with daily life and more graceful customers, the widespread use of table cloths has been withheld due to the concern about slipperiness described above. An object of the present invention is to provide a table cloth that does not easily slip off a table.

[0004]

The object of the present invention is to provide a polymer block A mainly composed of vinyl aromatic compounds.
And at least two polymer blocks B mainly composed of a conjugated diene compound, and
At least one polymer block B is composed of fibers comprising a hydrogenated block copolymer C obtained by hydrogenating a block copolymer at the end of a polymer chain and a polyolefin D, and the hydrogenated block copolymer Polymerization ratio (C / D) of C and polyolefin D is 40/60 to 99/1
This is achieved by a table cloth composed of a stretchable non-woven fabric.

The stretchable nonwoven fabric used in the table cloth of the present invention is characterized by a high friction coefficient. However, since the coefficient of friction decreases as the polymerization ratio of polyolefin increases, it is not suitable for use as a table cloth. On the other hand, if the polymerization ratio of the polyolefin is too small, the coefficient of friction increases, but the tackiness also increases, which is not preferable. Therefore, it suffices to find a preferable friction coefficient according to the use of the table cloth and to determine the polymerization ratio of the polyolefin corresponding thereto. From this point of view, the preferable polyolefin polymerization rate of the stretchable nonwoven fabric for table cloth of the present invention is 10 to 30 wt%. In this way, in the stretchable nonwoven fabric in which the polymerization ratio of polyolefin is 10 to 30 wt%, the constituent fibers can be ultrafine fibers, and as a result, a table cloth having an extremely soft texture can be produced. Further, since the stretchable nonwoven fabric having the polymerization ratio of the polyolefin in this range has an excellent elongation recovery property, when it is used as a table cloth, the fitting property to the table can be enhanced.

Further, the elastic nonwoven fabric used in the table cloth of the present invention has excellent strength, elongation, weather resistance, light resistance,
It has the characteristic of having heat resistance and chemical resistance. Therefore, even if this stretchable nonwoven fabric is used as a table cloth for a long time, the quality of the table cloth does not deteriorate. The table cloth of the present invention has a basis weight of 70 to 100 g / c.
m ² , thickness 0.1 to 1 mm, more preferably 0.2 to 0.
It is preferable to use a stretchable nonwoven fabric of 6 mm.

The table cloth of the present invention is made by cutting the elastic nonwoven fabric into a predetermined shape. At that time, if necessary, the elastic nonwoven fabric may be subjected to embossing, printing such as gravure printing, offset printing, and silk printing. When it is used as a table cloth, it is preferable to use it so that the surface not subjected to post-processing such as printing comes into contact with the table surface.

Use of, for example, styrene, α-methylstyrene, vinyltoluene, p-tert-butylstyrene or the like as the vinyl aromatic compound constituting the block copolymer before hydrogenation (hereinafter referred to as precursor polymer) in the present invention. And styrene is particularly preferred. These materials may be used alone or in combination of two or more. Further, as the conjugated diene compound constituting the precursor polymer, for example, 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3
-Butadiene and the like can be used, with butadiene and isoprene being particularly preferred. These materials may be used alone or in combination of two or more. These precursor polymers can be produced by sequentially performing block copolymerization using a lithium alkyl catalyst, or by sequentially performing block copolymerization and then performing a coupling reaction.

The precursor polymer thus obtained is
It is then selectively hydrogenated. That is, the hydrogenation reaction is a known hydrogenation catalyst, for example, a noble metal-based catalyst such as platinum or palladium, Raney nickel, an organonickel compound, an organocobalt compound or a catalyst obtained by combining these compounds with another organometallic compound. And so on. The titanocene compound is disclosed in JP-A-61-1554.
As disclosed in Japanese Patent No. 46, since it has a very high activity as a hydrogenation catalyst for a precursor polymer, it is possible to carry out a hydrogenation reaction with a small amount of a catalyst, and the catalyst residue has a heat resistance of a hydrogenation block copolymer. Since it does not adversely affect the stability, it is not necessary to remove the catalyst residue,
Particularly preferred.

The hydrogenation is preferably carried out selectively with respect to the double bond of the conjugated diene compound. That is, the double bond of the conjugated diene compound is not preferable because it causes deterioration of weather resistance, light resistance and heat resistance of the nonwoven fabric. Further, hydrogenation of a vinyl aromatic compound lowers the fluidity, which is not preferable in terms of spinnability. At least 80% by weight, preferably 90% by weight or more of the conjugated diene compound is hydrogenated, and 20% by weight or less, preferably 5% by weight of the vinyl aromatic compound.
It is preferable to partially hydrogenate the following so as to be hydrogenated in terms of weather resistance, light resistance, heat resistance and spinnability of the nonwoven fabric.

The number average molecular weight of the entire precursor polymer (hereinafter referred to as Mn
Abbreviated) is 30,000 to 65,000, preferably 35,000 to 60,000, more preferably 4
It may be in the range of 50,000 to 55,000. When the Mn is low, the strength of the single fiber is lowered, which causes the strength of the nonwoven fabric to be lowered. In particular, when Mn is less than 30,000, the viscosity of the polymer is lowered and chips cannot be formed, so that a nonwoven fabric cannot be obtained. On the other hand, when Mn is high, the melt viscosity of the hydrogenated block copolymer is increased, and the die pressure is increased, so that the spinnability is likely to be poor, and the Mn is 65.0
If it exceeds 00, the fiber cannot be formed.

The content of the vinyl aromatic compound in the precursor polymer is in the range of 15 to 40% by weight (hereinafter abbreviated as wt%), preferably 20 to 35% by weight. In the hydrogenated block copolymer, it is responsible for the strength of the non-woven fabric from which the so-called hard segment vinyl aromatic compound is obtained, and the stretchability of the non-woven fabric from which the conjugated diene compound is the soft segment is obtained. However, in terms of physical properties of the polymer, the polymer strength increases as the content of the vinyl aromatic compound increases, but the strength of the nonwoven fabric has the maximum value with respect to the content of the vinyl aromatic compound. That is, when the content of the vinyl aromatic compound is less than 15% by weight, the strength of the nonwoven fabric decreases. On the other hand, the content of vinyl aromatic compound is 40 wt%
If it exceeds, the strength and elongation of the non-woven fabric are lowered and the nonwoven becomes hard. Furthermore, in this case, melt viscosity increases, die pressure increases, spinnability becomes poor, and the resulting non-woven fabric also contains polymer beads, the average fiber diameter increases, the dispersibility of single fibers deteriorates, and the product feel , The appearance becomes worse. As a result, a usable nonwoven fabric cannot be obtained. Therefore, when the content of the vinyl aromatic compound in the precursor polymer is in the range of 15 to 40 wt%, the spinnability becomes good, and the nonwoven fabric having excellent strength and elongation and having a soft texture can be obtained. .

The 1,2-bond amount of the conjugated diene in the conjugated diene compound of the precursor polymer is in the range of 20 to 50 wt%, preferably 25 to 45 wt%. If it is less than 20 wt%, the elongation recovery of the nonwoven fabric is poor and it is difficult to use as a nonwoven fabric. If it exceeds 50 wt%, the spinnability is deteriorated and a good web cannot be obtained.

In the nonwoven fabric used in the present invention, at least 1
It is essential that the individual polymer blocks B are at the ends of the polymer chains of the precursor polymer. That is, the spinnability and the physical properties of the nonwoven fabric change depending on the proportion of the polymer block B occupying the ends of the polymer chain. The ratio of the polymer block B occupying the end of the polymer chain in the precursor polymer is
3 to 25 wt%, especially 5 to 20 wt% is preferable. If it is less than 3% by weight, the melt viscosity becomes high and the spinnability becomes poor so that a good web cannot be obtained.

Examples of the polyolefin used in the present invention include polyethylene, polypropylene, a copolymer of propylene and ethylene or an α-olefin such as 1-butene, and the like. A block copolymer of propylene and ethylene and polypropylene, Polyethylene is particularly preferred. As polypropylene, polypropylene having a number average molecular weight (Mn) of 2,000 to 60,000 and an MFR (melt flow rate) of 50 to 10,000, preferably 50 to 150 is preferably used, and a number average molecular weight of polyethylene ( Mn) 2,000-30,000
It is preferable to use polyethylene having The use of polyethylene is preferable because it lowers the elongation recovery rate.

The two polymers may be mixed in a single fiber, in which fibers made of the respective polymers are mixed in a nonwoven fabric, and in the nonwoven fabric, the above two states are mixed. There is a state of doing. Among them, the state of mixing in a single fiber is particularly preferable. Examples of the method for mixing the hydrogenated block copolymer and the polyolefin include a method of chip blending during spinning, and a method of using chips in which two kinds of polymers are melt-mixed in advance. The method of mixing these two polymers is not particularly limited, but the latter method is preferred.

The fibers in the stretchable nonwoven fabric used in the present invention may be mixed with a third polymer in addition to the above-mentioned polyolefin within a range not departing from the object of the present invention, and further in the stretchable nonwoven fabric used in the present invention. Other fibers may be mixed within the range not departing from the object of the present invention.

The number average molecular weight of the polyolefin (M
As n) is smaller, the elongation recovery rate tends to be higher at the same mixing ratio. The reason why such a tendency occurs is not clear, but the conjugated diene compound of the hydrogenated block copolymer and the polyolefin form a microdomain structure, and this structure is easier to form as the number average molecular weight of the polyolefin is smaller. It is estimated that there is.

As described above, when polypropylene is added as a polyolefin to the hydrogenated block copolymer,
The melt viscosity of the mixed polymer is reduced, the spinnability is remarkably improved, it is possible to increase the pressure under gas conditions, and the average fiber diameter is 10μ.
It is characterized in that ultrafine fibers of m or less can be easily obtained.
Further, the mixing of polypropylene has the effect of further improving the strength of the nonwoven fabric.

The average fiber diameter of the fibers constituting the stretchable nonwoven fabric used in the present invention is 50 μm or less, preferably 0.5 to
It is 30 μm. When the thickness is 0.5 μm or less, the nonwoven fabric is flexible but low in strength, resulting in poor breathability and moisture permeability. on the other hand,
When the thickness is 50 μm or more, the nonwoven fabric has a rough feeling and a hard texture, and also has poor water pressure resistance. Especially, the fiber diameter is 10μ
When it is m or less, and more preferably in the range of 1.0 to 6.0 μm, air permeability, moisture permeability and texture are improved, and further water pressure resistance is increased and dust resistance is excellent, which is particularly preferable.

As a method for producing the elastic nonwoven fabric used in the present invention, a melt blow method or a spun bond method can be used, and a fiber obtained by the melt spinning method is formed into a sheet by a usual dry method or a wet method. Can be used. However, from the viewpoint of spinnability, it is particularly preferable to use the melt blow method.

[0022]

【Example】

The table cloth of the present invention will be described below with reference to examples.
Example 1 A butadiene-styrene-butadiene-styrene type block copolymer (composition ratio wt% 10-
12.5-65-12.5) was synthesized as a precursor polymer. In this precursor polymer, Mn is 49,000,
Polystyrene content S is 29 wt%, 1,2 of conjugated diene
The amount of binding V was 36 wt%. This precursor polymer was hydrogenated and 0.5 wt% of a hindered amine stabilizer was added to form pellets, which were used as a raw material (hydrogenated block copolymer). The obtained hydrogenated block copolymer and Mn50,0
15 wt% polypropylene with 00 (MFR80)
The mixture was added, made into chip pellets, charged into an extruder, heated and melted (extruder temperature: 290 ° C.), and then fed into a nozzle.
This nozzle has 200 nozzles in a row at a pitch of 1 mm 0.4
The copolymer had an orifice of mmφ, and the copolymer was discharged into the high-speed fluid at a discharge rate of 0.2 g / min from each orifice. Using superheated steam adjusted to 380 ° C. as a fluid, the superheated steam is jetted at a pressure of 3.0 kg / cmG from the slit of the melt-blowing nozzle toward the molten polymer, whereby the molten polymer is towed and thinned. To do. Then, the fine fibers are collected on a moving net conveyor (distance between the die and the collector is 40 cm) to obtain a web. The resulting web is then heated to 90 ° C. on a hot embossing roll.
A non-woven fabric was obtained by thermal bonding at a temperature of 15 ° C. and a pressure of 15 kg / cmG. The obtained non-woven fabric has a basis weight of 102 g / m ² , an average fiber diameter of 17.5 μm, a strength of 550 g / cm, and an elongation of 320.
%, And the elongation recovery rate was 93%.

This non-woven fabric was cut into a size of 115 cm × 160 cm to form a table cloth, which was placed on a 75 cm × 120 cm square table and used as a dining table for one week, but during that time, the table cloth did not slip off the table.

The average fiber diameter and the like were measured by the following method. ◎ Average fiber diameter (μm); arbitrary 10 of non-woven fabric sample
10 photographs are taken of the place with an electron microscope (magnification: 2000 times). The diameter of any 10 fibers is measured per photograph and this is done for 10 photographs. 10 in total
The measured value of the fiber diameter of 0 fibers is obtained and the average value is calculated. ◎ Strength and elongation: Non-woven fabric sample with a width of 2 cm is JIS
It measures according to L-1096. At that time, the gripping interval is 5 cm and the pulling speed is 10 cm / min. From the values at break, calculate the strength and elongation per 1 cm width. ◎ Elongation recovery rate: Non-woven fabric sample with a width of 2 cm is JIS L
It is measured according to -1096. Gripping interval 12 at that time
cm, tensile speed 10 cm / min, 50% elongation, immediately recovering to original length at the same speed. Before extension, the difference in extension before and after extension of a 10 cm long line written in the extension direction (a) (mm)
Then, the elongation recovery rate is calculated by the following formula.

[0025]

Since the coefficient of friction of the table cloth according to the present invention is higher than that of the table cloth made of a conventionally known material, it does not slip off the table during use. Although this table cloth is made of a non-woven fabric, it has sufficient strength and good weather resistance and light resistance, and as a result, it can be used for a long period of time without deterioration in quality.

Claims (1)

[Claims] 1. A polymer having at least two polymer blocks A mainly composed of a vinyl aromatic compound, at least two polymer blocks B mainly composed of a conjugated diene compound, and at least one polymer. Block B is composed of fibers consisting of hydrogenated block copolymer C and polyolefin D obtained by hydrogenating a block copolymer at the end of the polymer chain, and polymerization of hydrogenated block copolymer C and polyolefin D A table cloth made of a stretchable nonwoven fabric having a ratio (C / D) of 40/60 to 99/1.