JPH01201583A - Synthetic fiber for reinforcing polyvinyl chloride-based resin tile and production of said fiber - Google Patents

Abstract

PURPOSE:To obtain the title reinforcing fiber effective as an alternative to asbestos, by assembling short fibers with each specified single fiber fineness and fiber length coated with a thermally adhesive resin, consisting of a thermoplastic polymer having a melting point at or higher than a specified temperature so as to become specified specific volume. CONSTITUTION:Undrawn yarns made of synthetic fiber consisting of a thermoplastic polymer with a melting point of >=250 deg.C (e.g., polyester) are drawn and coated with a thermoplastic resin (pref. water-dispersible polyester, polyurethane). The resultant drawn yarns are crimped if needed, then dried, heat set and assembled so as to become a tow of 3,000-70,000de with a single fiber fineness of 0.1-30de. The resulting tow is then cut into short fibers 1-20mm in length, which is then assembled so as to become 3-15cm<3>/g in its specific volume. The short fibers thus obtained is good in the dispersibility in a polyvinyl chloride-based resin, thus enabling polyvinyl chloride-based resin tiles with excellent surface smoothness and sufficiently high tile strength to be produced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a synthetic fiber for reinforcing polyvinyl chloride resin tiles and a method for producing the same, and more specifically, a synthetic fiber for reinforcing polyvinyl chloride resin tiles that can be substituted for ashest. Concerning synthetic fibers and their manufacturing methods.

(Prior Art) Conventionally, polyvinyl chloride resin tiles (hereinafter sometimes referred to as PVC tiles) are mainly formed from polyvinyl chloride resin (hereinafter sometimes referred to as PVC) and calcium carbonate. Asbestos is added as a reinforcing material.

By the way, asbestos can cause silicosis in those who handle it,
Also, since it is suspected of being carcinogenic, there are extremely serious problems with its use from the standpoint of occupational health.

For this reason, Japanese Patent Application Laid-Open No. 60-155780 proposes a PVC tile that uses a combination of special calcium carbonate and conventionally used calcium carbonate without using asbestos. The strength of PVC tiles is inferior to that of PVC tiles that use asbestos as a reinforcing material.

(Problem to be solved by the invention) As a countermeasure to this problem, the present inventors have proposed
In Publication No. 3, when polyvinyl alcohol short fibers, which are said to be able to replace asbestos as a concrete reinforcing material, were used as a reinforcing material for PVC tiles, the resulting PVC tiles had uneven surfaces and had low strength. It was something.

In the PVC tile molding process, PVC powder,
This is because the calcium carbonate powder and the reinforcing material are kneaded at a high temperature of 80 to 180° C., so the short polyvinyl alcohol fibers used as the reinforcing material are fused and formed into a lump.

For this reason, the present inventors tried using polyester short fibers, which have better heat resistance than polyvinyl alcohol short fibers, as a reinforcing material, but although the fusion between the reinforcing materials was resolved, no lumps still formed. Therefore, the reinforcing effect could not be sufficiently exhibited, and the surface of the PVC tile could not be made smooth.

As described above, even if conventional synthetic fibers are simply used as reinforcing materials for PVC tiles, fully satisfactory PVC tiles cannot be obtained.

An object of the present invention is to provide a synthetic fiber for reinforcing a PVC tile and a method for producing the same, with which a high-strength and smooth PVC tile can be obtained.

(Means for Solving the Problems) The present inventors have conducted various studies to achieve the above object, and have found that short fibers (hereinafter sometimes simply referred to as short fibers) made of synthetic fibers used as reinforcing materials (comparable to volume) is pv
It was found that short fibers were significantly larger than C powder and calcium carbonate powder, and it was difficult for short fibers to be mixed with calcium carbonate and PVC during the kneading process, resulting in lumps.

Therefore, the present inventors investigated ways to facilitate the mixing of short fibers in the kneading process, and found that by once converging the short fibers supplied to the kneading process into a bundle, the short fibers can be easily mixed in the kneading process. The present invention was achieved by discovering that the present invention can be dispersed uniformly.

That is, the present invention is made of a thermoplastic polymer having a melting point of 250° C. or higher, a single fiber fineness of 0.1 to 30 de, and a fiber length of 1 to 30 de.
Polyvinyl chloride-based resin for reinforcing tiles, characterized by short fibers having a specific volume of 3 to 15 cm3/g and having a specific volume of 3 to 15 cm3/g. A synthetic fiber end drawn yarn made of synthetic fiber and a thermoplastic polymer with a melting point of 250°C or higher is drawn, a thermoadhesive resin is applied, and the yarn is dried and heat-fixed to have a single yarn fineness of 0.1.
~30de, fineness per width 10 is 30.000
~? This is a method for producing a polyvinyl chloride resin tile reinforcing synthetic fiber, which is characterized in that it is bundled into a tow of 0.000 de, and then cut into short fibers with a fiber length of 1 to 20 deg.

The synthetic fiber of the present invention needs to be made of a thermoplastic polymer having a melting point of 250° C. or higher.

Low melting point polyethylene (melting point 125-135°C), polypropylene (melting point 165-173°C), nylon 6
(215-220°C), etc., is exposed to temperatures of 80-180°C during the tile raw material kneading process, which causes the fibers to stick and form clumps, causing tile defects. Thermoplastic polymers with a melting point of 250°C or higher include:
Relatively low cost polyesters, especially polyethylene teretate, are preferred.

Furthermore, the synthetic fiber of the present invention has a single yarn fineness of 0.1 to 30 d.
e. It must be composed of short fibers with a fiber length of 1 to 20. If the single yarn fineness exceeds 30 denier, the tile reinforcing effect will be insufficient in areas where the synthetic fiber blend ratio is low (3 parts by weight or less), and if it is less than 0.1 denier, the fibers in the tile will not be strong enough. The dispersion becomes poor, causing uneven defects in the tiles, and a sufficient reinforcing effect cannot be obtained. On the other hand, if the fiber length exceeds 20 tsuru, the fibers become entangled during the raw material kneading process, resulting in uneven tile defects, and if the fiber length is less than 100 ml, a sufficient tile reinforcing effect cannot be obtained.

Furthermore, the synthetic fibers of the present invention need to be bundled into a bundle so that the short fibers have a heat-adhesive resin and have a specific volume of 3 to 15 cm<3>/g. If the specific volume exceeds 15 aa/g, the fibers will not be sufficiently mixed and dispersed into other raw materials during the raw material kneading process, resulting in uneven tile defects. On the other hand, if the fibers are fixed and bunched until the specific volume is less than 3 aj/g, the fibers will not be sufficiently dispersed during the kneading process, causing uneven tile defects.
Moreover, a sufficient reinforcing effect cannot be obtained. Here, the specific volume is calculated by placing 400 g of sample fiber in a cylindrical container with a cross-sectional area of 400 CO1'' and measuring the height of the sample fiber when a load of 330 g is applied from above.

The thermoadhesive resin used in the present invention is not particularly limited as long as it has the function of converging fibers, but judging from the performance of the tile, water-dispersible polyester resin (melting point 80 to 240°C) is mainly used. It is preferable to use it as a component.

The polyvinyl chloride resin tile to which the synthetic fiber of the present invention is applied as a reinforcing material is obtained by adding a plasticizer to the polyvinyl chloride resin in an amount of 20 parts by weight or less based on the total amount, and increasing the amount with an extender such as calcium carbonate. A binder is added to improve workability during the tile manufacturing process, and it also contains stabilizers, colorants, etc. The mixing ratio of the synthetic fiber tile of the present invention is usually 0.5 to 20 parts by weight.

In order to produce such synthetic fibers of the present invention, drawn synthetic fiber ends made of a thermoplastic polymer having a melting point of 250° C. or higher, such as polyester, are drawn, a thermoadhesive resin is applied, and if necessary, After crimping, drying and heat setting, the single yarn fineness is 0.1 to 30 de, and the fineness per 1 cm of tow width is 30.000 to 30. After converging to a fiber length of 0.0OOde(7)'7, the fibers may be cut into short fibers having a fiber length of 1 to 20+u.

In order to make the specific volume of the resulting synthetic fibers 15 cm/g or less, it is necessary to apply a thermoadhesive resin and bundle the fibers into tows with a fineness of 70.0 OOde or less per tow width 1a11, and In order to make the specific volume 3 cm3 / g or more, the tow width 1 (the fineness per 3 is 30,000
It is necessary to focus the light so that it is less than or equal to de.

In order to set the specific volume of the synthetic fiber to 3 to 15 cnf/g, the amount of the thermally adhesive resin adhered, the type of the thermally adhesive resin, the fineness of the single fibers, etc. may be appropriately selected. To control the amount of heat-adhesive resin deposited, the tow immersed in a heat-adhesive resin bath is passed through a pair of squeezing rollers and squeezed to the desired amount before drying and heat-setting. Bye. In this case, the tow fineness per squeeze roller width 1c11 is 25.000 to 60.
It is desirable to adjust it so that it becomes 000de.

(Examples) Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

In the following Examples and Comparative Examples, the production of polyvinyl chloride tiles and the determination of tile surface smoothness and strength were performed as follows.

(a) Production of polyvinyl chloride tiles After kneading the following composition with a small test roll for 5 minutes at 80 to 180°C,
The thickness was adjusted to 2 mm and taken out as a 30cm x 30cm tile piece.

Compounded polyvinyl chloride 13 parts by weight Heavy calcium carbonate 78 parts by weight DHP 4 parts by weight Binder 5 parts by weight Synthetic fiber 1 part by weight (b) Judgment of tile surface smoothness Visually inspect the surface of a tile piece (30 cm x 30 cm) The number of convex defects was observed and scored according to the following criteria.

1 piece or less / 30aa x 30cm: 52
~3 pieces / 30c! l x 30 (IJ: 4
4-10 pieces / 30cm x 3Qcm: 3
11-20 pieces / 30cm x 30cm:
221 or more / 30cn x 30cm: 1
(c) Judgment of tile strength In a constant temperature room adjusted to 3°C, drop a 50g iron ball from a height of 1.5m onto the above test tile piece placed horizontally on the floor, and observe the occurrence of cranking. The samples were numbered from 1 to 10, with 1 being a large crack and 10 being no crack at all.

Examples 1-15, Comparative Examples 1-8 After aligning and stretching a plurality of unstretched fibers of various synthetic fibers shown in Table 1, 2. The stretched tow was run while immersed in an aqueous dispersion of a heat-adhesive resin shown in Table 1 (concentration 3 weight 96), and then the amount of resin adhesion was controlled with a pair of squeezing rollers. In this case, the thickness of the tow when passing through the squeezing roller is 40
, 000de/ca+, the fineness of tow after heat setting is 4
It was 0.000-50.0OOde/Cl11.

The tow that passed through the squeezing roller was dried, heat-set, and then cut into a predetermined length. The single yarn fineness and fiber length were changed as shown in Table 1.

Furthermore, in Comparative Example 1, conventional asbestos was blended without using synthetic fibers, and the amount of asbestos blended into the tile was 2 parts by weight.

The results are shown in Table 1, and as is clear from this table, the polyvinyl chloride tiles (Examples 1 to 15) using the synthetic fibers of the present invention had excellent surface smoothness, and the fiber content was reduced. Even when the asbestos was reduced to 1/2, the same or higher tile strength could not be obtained compared to the tile using conventional asbestos (Comparative Example 1).

On the other hand, when the single yarn fineness exceeds 30 denier (
Comparative Example 2) and when the fiber length is less than lam (Comparative Example 3)
) had insufficient tile strength.

When synthetic fibers with a melting point of 250°C or lower are used (Comparative Examples 7 and 8), poor dispersion occurs, likely due to softening or melting due to the heat received during kneading, resulting in poor tile surface smoothness. , the tile strength was lower than that of the conventional asbestos tile (Comparative Example 1).

Furthermore, when the fiber length exceeded 20 m (Comparative Example 4), convex defects occurred due to fiber entanglement, and at the same time, a decrease in tile strength was observed due to poor dispersion.

Water-dispersible polyester (Examples 1 to 9.12 to 14) and polyurethane (Example 10) as types of thermoadhesive resin
In addition, the raw cotton coated with an appropriate amount of ethylene/vinyl acetate copolymer (Example 11) has a low specific volume and is well dispersed in the raw material, resulting in good surface smoothness and sufficient surface smoothness. Tile strength was obtained, but high-density polyethylene (
In the case of using Comparative Example 5), the specific volume was high, resulting in poor dispersion, and both smoothness and tile strength were poor.

When the specific volume of the raw cotton was changed by changing the amount of heat-adhesive resin adhered, the amount of adhesion was large and the specific volume was 3-7 g (Example 12), but even when asbestos was used (comparison) Performance equivalent to Example 1) was obtained. In addition, if the amount of heat-adhesive resin deposited is too small and the specific volume exceeds 15 cd/g (Comparative Example 6), the difference in specific volume with other raw materials becomes large, resulting in poor dispersion and a smooth surface. The properties of the tiles were poor, and the tile strength was also low.

(This page, below margin) Example 16.1? , Comparative Examples 9 and 10 In Example 2, the thickness of the tow when passing through the squeezing roller was changed, and the fineness per tow width 11 after heat setting was variously changed as shown in Table 2.

The results are shown in Table 2, and the fineness of the tow after heat setting (per 1 cIII of tow width) was 30.000 to 70.00.
000 de (Examples 16 and 17), good results were obtained for both tile surface smoothness and tile strength, but in the case of 30.000 de and no grooves (Comparative Example 9), the specific volume of raw cotton was high. This resulted in poor dispersion during tile production, resulting in insufficient surface smoothness and tile strength. In addition, when it exceeds 70.000 de (Comparative Example 10), the binding force between the single fibers is too strong, resulting in a low specific volume, making it difficult to disperse the single fiber units in the kneading process of tile manufacturing, and making the tile surface smooth. The properties and tile strength were insufficient.

(This page, blank spaces below) (Effects of the invention) Since the synthetic fiber for reinforcing PVC tiles of the present invention does not use asbestos, there is no problem in terms of occupational health, and it is equivalent to or even better than PVC tiles using asbestos. A PVC tile having the above performance (tile surface smoothness, tile strength) can be obtained.

Claims (1)

[Claims] 1. It is made of a thermoplastic polymer with a melting point of 250°C or higher, has a single filament fineness of 0.1 to 30 de, a fiber length of 1 to 20 mm, and is provided with a thermoadhesive resin. A synthetic fiber for reinforcing polyvinyl chloride resin tiles, characterized by short fibers bundled into bundles with a specific volume of 3 to 15 cm^3/g. 2. A synthetic fiber end drawn yarn made of a thermoplastic polymer with a melting point of 250°C or higher is drawn, a thermoadhesive resin is applied, and the yarn is dried and heat-set to produce a yarn with a single yarn fineness of 0.1 to 30 de and a tow. A synthetic fiber for reinforcing polyvinyl chloride resin tiles, which is bundled into tows with a fineness of 30,000 to 70,000 per 1 cm width, and then cut into short fibers with a fiber length of 1 to 20 mm. Manufacturing method.