JPH02160996A - Production of wet non-woven fabric - Google Patents

Abstract

PURPOSE:To obtain a wet non-woven fabric having large strength in wet state by blending natural pulp with specific polyester fiber and binder fiber at a definite amount and subjecting the blend to wet paper making. CONSTITUTION:(A) Natural pulp is blended with (B) a polyester fiber being a polyethylene terephthalate based short fiber containing 0-20mol% copolymerized isophthalic acid and having 0.006-0.03 double refraction and <=1.3 denier single yarn fineness and (C) a binder fiber for short fiber containing a polyesteramide obtained by copolymerizing terephthalic acid with isophthalic acid, 5-sulfoisophthalic acid metallic salt, 1,5-pentadiol and/or 1,6-hexanediol, aminododecanoic acid and/or aminoundecanoic acid and having <=120 deg.C melting point as an adhesive component at a weight ratio of competent A/component B/component C of 50-80/15-45/5-15 and then the blend is subjected to wet paper making to provide the aimed non-woven fabric.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to a method for producing a wet-laid nonwoven fabric, and more specifically relates to a method for producing a wet-laid nonwoven fabric, and more specifically, a method for producing a wet-laid nonwoven fabric.
The present invention relates to a method for producing a wet-laid nonwoven fabric with high strength, particularly a wet-laid nonwoven fabric that has high strength in a wet state, by mixing paper raw material (hereinafter referred to as natural pulp) made of natural cellulose fibers (hereinafter referred to as "natural pulp").

<Prior Art> Conventionally, in producing wet-laid nonwoven fabrics, attempts have been made to mix synthetic fibers, such as short fibers made of synthetic resins such as polyester, polyamide, and polystyrene, as reinforcing materials into paper raw materials made of natural pulp. (Unexamined Japanese Patent Publication No. 1983)
-191300). These synthetic fibers have better physical properties than natural pulp, so if they are mixed with natural pulp to make reinforced paper, they will exhibit superior functionality. In particular, aromatic polyester fibers such as PET are suitable for the above purpose due to their excellent properties. A method for producing such a wet-laid nonwoven fabric mixed with natural pulp involves adding natural pulp, synthetic short fibers, and short fibers having adhesive properties and paper-making properties as a binder (for example, polyvinyl alcohol fibers commonly used as water-soluble binder fibers) in water. Generally, a process is adopted in which the fibers are dispersed in an appropriate ratio, made into paper, passed through heated rolls at around 110'C in a wet state to bond the fibers together, and then heated and dried. However, the above-mentioned synthetic short fibers, especially aromatic polyester fibers such as PET, are hydrophobic and have low affinity with polyvinyl alcohol fibers, which are usually used as binders, and have low adhesive strength, so when used as non-woven fabrics. Its power is not fully demonstrated.

To improve this point, a 5-metal sulfoisophthalic acid component is added to PET.

A binder fiber made by copolymerizing a large amount of diethylene glycol, polyoxyalkylene glycol, etc. has also been proposed (Japanese Patent Laid-Open No. 62-28500). However, although such hydrophilic polyvinyl alcohol fibers do have a somewhat better affinity for synthetic fibers such as PET fibers than water-soluble polyvinyl alcohol fibers and can improve paper strength, the extent to which they do so is limited. has not yet reached a satisfactory level. In addition, in order to improve the hydrophilicity of the aromatic polyester fiber itself as a reinforcing fiber and its affinity with binder fibers, attempts have been made to incorporate metal salts of alkyl sulfonic acids. Although considerable effects have been obtained in combination with polyester binder fibers, this is still insufficient for applications that require high nonwoven fabric strength, such as adhesive tape base materials and vacuum cleaner filters. Furthermore, nonwoven fabrics manufactured using polyvinyl alcohol or hydrophilic polyester as a binder cannot be used in applications where they are used in wet conditions, as the strength of the nonwoven fabrics in wet conditions is significantly lower than that in dry conditions. .

Although it is known that aromatic polyester fibers have excellent qualities as reinforcing materials for wet-laid nonwoven fabrics,
It was difficult to make full use of it in reality.

<Objective of the Invention> The object of the present invention is to provide a wet-laid nonwoven fabric with high strength obtained by mixing PET as a reinforcing fiber with natural pulp, particularly a wet-laid nonwoven fabric with high strength in a wet state.

Solution> As a result of intensive studies to achieve the above object, the inventor has found that
We have discovered that the above object can be achieved by using polyethylene terephthalate short fibers having a specific birefringence as reinforcing fibers and using fibers whose main component is polyesteramide, which is made of a specific component, as binder fibers, This has led to the present invention.

<Structure of the Invention> That is, the present invention provides a method for producing a wet-laid nonwoven fabric in which natural pulp (8) polyester fibers (B) and binder fibers (C) are mixed and wet-laid paper is made. Birefringence o, ooe ~ 0.03 copolymerized with isophthalic acid
It is a polyethylene terephthalate short fiber with a single fiber fineness of 1.3 denier or less, and the binder fiber (C) is terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid metal salt,
A short fiber whose adhesive component is a polyesteramide having a melting point of 120°C or less obtained by co-condensing 1,5-pentadiol and/or 1,6-hexanediol, aminododecanoic acid and/or aminoundecanoic acid, and which is made of pulp. A method for producing a wet-laid nonwoven fabric, characterized in that the weight ratio of A/polyester fiber B/binder fiber C is 50 to 80/15 to 4,515 to 15.

In the present invention, the ester unit which is one component of the polyesteramide constituting the binder fiber C is a metal salt component of terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid, 1,5-pentadiol and/or 1,6 −
It is an ester unit composed of hexanediol. By combining these, it is possible to obtain a binder polymer that has high strength, high affinity for PET fibers, and sharply melts at 120° C. or lower.

The characteristic of sharp melting at 120°C or lower is generally required from the heat treatment conditions when making wet non-woven fabrics into V-formers, or even if aliphatic dicarboxylic acids are used, such characteristics cannot be achieved. It is possible to have it.

However, in this case, the resulting pinter polymer has low strength and thermal stability, and also has low affinity for PETl#A fibers, making it impossible to obtain a high-strength nonwoven fabric.

The ratio of terephthalic acid and isophthalic acid may be changed arbitrarily to lower the melting point to 120°C or less in combination with the amide unit, and the amount of the metal salt component of 5-sulfoisophthalic acid may be changed depending on the melt viscosity of the polymer. Don't let it get too high,
Usually, it is preferably 0.3 to 5.0 mol%, particularly preferably 0.5 to 3.0 mol%, based on the total dicarboxylic acid components. By copolymerizing this metal salt component of 5-sulfoisophthalic acid, the strength of the pinter polymer can be further improved, making it possible to obtain a highly strong nonwoven fabric.

The 5-metal sulfoisophthalic acid used here is represented by 803M, where M is preferably a metal, particularly an alkali metal (Na, Li, etc.). Preferred examples of the ester-forming derivatives include lower alkyl esters, phenyl esters, and glycol esters.

Glycol components other than those mentioned above, such as 1.4-
If butanediol or the like is used, there are disadvantages such as not being able to melt sharply at temperatures below 120°C, the thermal stability of the polymer being extremely poor, or the polycondensation reactivity being extremely low. No comparable binder polymer can be obtained.

Do, decanamide and/or undecanamide constituting the amide unit, which is another component of the polyester a,mid, are 1,2-aminododecanoic acid and/or 1
, 1-aminoundecanoic acid and their amino-forming derivatives, and the general formula] %Formula% In the polyesteramide of the present invention, the dodecanamide unit and the undecaneamide unit are each in the form of a single individual or a copolymer. They can be used without much difference in terms of polymerizability and physical properties, but they may be appropriately selected and used for the purpose of controlling melting point, crystallinity, etc.

Amide units other than those mentioned above have disadvantages such as a decrease in the crystallinity of the resulting polymer and a significantly low polycondensation reaction rate, and in either case, an excellent binder polymer cannot be obtained. The polyesteramide of the present invention is prephthalic acid or isophthalic acid.

Metal salt component of 5-sulfoisophthalic acid, 15-hentadiol and/or 1,6-hexanediol, 1
, 2-aminododecanoic acid and/or 1,1-aminoundecanoic acid are obtained by melt polymerization.

The bander fiber C may be composed of the above-mentioned binder component alone, or may be a composite fiber obtained by composite spinning with the binder component and another polyester having a higher melting point than the binder component. Such composite fibers may be of a side-pie-side type or a core-sheath type, as long as the binder component forms at least a portion of the surface. In this case, the binder component is preferably used in an amount of 5 parts by weight or more, and particularly preferred is a core-sheath type composite fiber in which the binder component is the sheath component and a high melting point polyester such as polyethylene terephthalate is the core component. Further, the shape of the fiber C is not particularly limited, but its fineness is usually 0.5 to 20 deniers, preferably 1.5 to 4 deniers, and its length is usually 20 mm or less, preferably about 2 to 10 deniers. It is.

Fiber C is used in an amount of 5 to 15 parts by weight per 100 parts by weight of the nonwoven fabric. If it is less than 5 parts, it is difficult to obtain sufficient strength;
If the amount exceeds 50%, the adhesive performance will no longer be improved and the cost will increase, which is not preferable.

Fiber B is made of polyethylene terephthalate polyester copolymerized with 0 to 20 mol % of an isophthalic acid component, and is a short fiber having a birefringence of 0.006 to 0.03 and a single filament fineness of 1.3 denier or less. If the birefringence is less than 0.006, the resulting nonwoven fabric will have low tear strength, resulting in a paper-like nonwoven fabric with poor flexibility and bulkiness. On the other hand, if the birefringence exceeds 0.03, both the tensile strength and tear strength of the resulting nonwoven fabric will become extremely low. Fibers having a birefringence of 0.006 to 0.03 can be obtained by appropriately adjusting the spinning speed, spinning cooling conditions, and the like. Here, birefringence is determined by using a Na light source, inserting a Bere J compensator into the optical path of a polarizing microscope, and measuring in α-bromnaphthalene.

Further, the single yarn fineness of the fiber B needs to be 1.3 denier or less, and preferably 0.5 denier or more. When the fineness exceeds 3 deniers, the tear strength of the resulting nonwoven fabric decreases. Moreover, a similar tendency is observed even when the fineness becomes smaller and the gap becomes larger.

Even if the birefringence and filament fineness of the fiber B satisfy the above-mentioned values, if the copolymerized amount of isophthalic acid exceeds 20 mol %, the strength of the resulting nonwoven fabric will be significantly reduced. The length of fiber B is usually 30 mm or less, preferably about 2 to 20 mm.

The polyester short fibers of fiber B are used in an amount of 15 to 45 parts by weight, preferably 20 to 40 parts by weight, per 100 parts by weight of the nonwoven fabric. If it is less than 15 parts, the effect of mixing polyester fibers will be small, and if it is more than 45 parts, the properties originally possessed by natural pulp will be impaired. The component A used in the present invention is a paper raw material made of natural cellulose.
Use 80 parts by weight. If it is less than 50 parts, the resulting nonwoven fabric will have a hard feel, and if it is more than 80 parts, the strength and dimensional stability of the nonwoven fabric will be poor.

To produce a nonwoven fabric from the binder fibers C, the fibers B, and the component A, there is no need to employ any special method, and the nonwoven fabric can be easily produced by the method described above.

<Operations and Effects of the Invention> Only by combining the above-mentioned ABC, a wet-laid nonwoven fabric mixed with natural pulp with high strength, particularly a wet-laid nonwoven fabric with high strength in a wet state, can be obtained. The detailed reason is still unknown or is thought to be as follows. It is generally said that the factors that influence adhesive strength are the affinity between the adhesive and the adherend and the cohesive force of the adhesive itself, but when manufacturing nonwoven fabric by mixing PET short fibers with natural pulp, However, the nature of the adherend is different (natural pulp is hydrophilic,
Since PET short fibers are hydrophobic, a highly strong nonwoven fabric cannot be obtained unless there is a binder that adheres well to both. When the polyester amide of the present invention is used as a binder, the ester unit mainly composed of terephthalic acid/isophthalic acid shows high affinity for PET short ma, while the amide unit shows high affinity for natural pulp due to hydrogen bonding etc. Adhere firmly. Furthermore, the ester unit has 5
- By copolymerizing the metal salt component of sulfoisophthalic acid, a physical cross-linking effect occurs between the molecules of polyesteramide, making it possible to increase the intermolecular cohesive force.

Furthermore, by using PET short fibers having the above-mentioned degree of orientation to be mixed with the natural pulp, these short fibers will be fused together during the heat treatment during paper making, so when used in combination with the above polyesteramide binder, non-woven fabrics can be created. can significantly increase its strength.

In addition, these adhesive mechanisms do not use water as a medium like polyvinyl alcohol binders or hydrophilic polyester binders, so even if the obtained nonwoven fabric is kept in a wet state, the adhesive strength may be weakened by water. It is possible to maintain the high strength originally possessed.

According to the present invention, a nonwoven fabric that can maintain high strength even in a wet state can be easily provided by a wet process, and has great industrial significance.

<Example> The present invention will be further explained in detail by giving examples. All parts in the examples are parts by weight. Furthermore, the abbreviations used in this example are as follows.

DMT, dimethyl terephthalate (terephthalic acid component) DMI dimethyl isophthalate (isophthalic acid component) SIDM; 5-sodium dimethyl sulfoisophthalate PMG, 1.5-bentanediol (pentamethylene glycol) HMG, 1.6-hexanediol (hexamethylene glycol) 12-ADA, 12-aminododecanoic acid 1l-AUA
; 11-aminoundecanoic acid [η]: Intrinsic viscosity measured at 30°C in orthochlorophenol solvent Example 1 (1) Production of C binder fiber 271.6 parts of dimethyl terephthalate, 29.1 parts of dimethyl isophthalate, 5 - 14.8 parts of sodium dimethyl sulfoisophthalate, 731 parts of 12-aminododecanoic acid,
207.7 parts of 1,6-hexanediol and 1-0.85 parts of tetrabutyl rapeseed as a catalyst were charged into a reactor equipped with a stirrer, a rectification column, and a methanol/water distillation condenser, and heated from 140'C to 220°C. The mixture was heated to .degree. C., and esterification and transesterification reactions were carried out while distilling methanol and water produced as a result of the reaction out of the system. After starting the reaction 4
In an hour, the indoor bath reached 220℃, and 61.2 parts of water and 102 parts
．． Transferred to a reactor equipped with 4 parts of methanol or a distillation condenser, added 1 part of the antioxidant "'Ilkanox 1010" and cooled to 200°C.
Gradually raise the temperature to 40'C and 1 rnm from normal pressure.
The polycondensation reaction was carried out without lowering the pressure to a high vacuum of H(l). A polynis sultylamide polymer with [η] of 0.8.73 was obtained in a total polycondensation reaction time of 6 hours. The melting point of the polymer was 117. It was ℃.

Next, this polyesteramide is used as a sheath, and [η] 0
．． Composite fibers with a single fiber fineness of 3 denier were obtained by conventional composite spinning using PET No. 64 as a core at a core/sheath weight ratio of 50,150, and the composite fibers were cut into 5 lengths.

(2) Production of B fibers 873 parts of dimethyl terephthalate, 97 parts of dimethyl isophthalate, 558 parts of ethylene glycol, and 0.245 parts of manganese acetate tetrahydrate as a transesterification catalyst were added to a stirrer, a rectification column, and a methanol distillation condenser. The reaction mixture was charged into a reactor equipped with a reactor, heated from 140°C to 220°C, and transesterification was carried out while methanol produced as a result of the reaction was distilled out of the system. The temperature of the indoor bath reached 240℃ 3 hours after the reaction started.
320 parts of methanol were distilled out. Here, 0.175 parts of 1-trimethyl phosphate was added as a stabilizer, and 0.39 parts of antimony trioxide was added as a polycondensation catalyst.
4.85 parts of titanium dioxide were added as a matting agent.

The reaction mixture was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and the temperature was gradually raised from 240°C to 285°C, while the pressure was lowered from normal pressure to a high vacuum of 1 mm H (1 mm H). A condensation reaction was carried out.

A polymer having [η] of 0.642 was obtained in a total polycondensation reaction time of 3 hours. This was melt-spun to obtain a fiber with a single fiber fineness of 1.1 denier and a birefringence of 0.012, and then a length of 5 mm.
It was cut into

(3) Production of nonwoven fabric Single yarn fineness 3 denier obtained in (1) above, fiber length 5ff1
10 parts of composite fiber of m, single yarn fineness of 1.1 denier obtained in (2).

30 parts of short polyester fibers with a birefringence of 0.012 and a fiber length of 5 are mixed in a ratio of 60 parts of natural pulp, dispersed in water to a fiber concentration of 0.03% by weight, and manufactured by Kumagai Riki Kogyo ■. , R, is supplied in a wet state to a mold rotary dryer, and is subjected to drying and heat treatment at the same time.
The tensile strength was measured according to -8113, and this value was taken as the dry strength.

Moreover, after the nonwoven fabric obtained above was left to stand and immersed in water at 25° C. for 1 hour, the tensile strength was measured in the same manner, and this value was defined as the wet strength. The results are shown in Table 1.

Example 2 (1) Production of binder fiber of C Dimethyl terephthalate 261.9 parts, dimethyl isophthalate 38.8 parts 5-sodium dimethyl sulfoisophthalate 14.8 parts, 11-aminoundecanoic acid 683 parts.
4 parts, 183 parts of 1,5-bentanediol, and 0.85 parts of Te1-butyl titanate as a catalyst with a stirrer,
The mixture is charged into a reactor equipped with a rectification column and a methanol/water condenser, heated from 140°C to 220°C, and esterification and transesterification reactions are carried out while distilling methanol and water produced as a result of the reaction out of the system. Ta. Four hours after the start of the reaction, the internal temperature reached 220°C, and 61.2 parts of water and 1
02.4 parts of methanol was distilled off. The obtained reaction product was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and the antioxidant "Ilkanox 101" was added.
After cooling to 200°C, the temperature was gradually raised from 200°C to 240°C and 1 im from normal pressure.
The polycondensation reaction was carried out without lowering the pressure to a high vacuum of HO.

A polynis sultylamide polymer having [η] of 0.864 was obtained in a total polycondensation reaction time of 6 hours. The melting point of this polymer was 118°C.

Next, this polyesteramide is used as a sheath, and [η]0.
Using PET 64 as a core, a core/sheath composite fiber was spun using a conventional method at a core/sheath weight ratio of 50,150 to obtain a composite fiber having a single filament fineness of 3 denier, which was cut into a length of 51iI11.

(2) Monofilament fineness 3 obtained in the above (1) as the binder fiber for nonwoven fabric production C
The same procedure as in Example 1 was conducted except that 10 parts of composite fibers having a denier and a fiber length of 5 mm were used. The results are shown in Table 1.

Example 3 (1) Production of binder fiber of C 271.6 parts of dimethyl terephthalate, 59.2 parts of dimethyl 5-sodium sulfoisophthalate, 731 parts of 12-amidodecanoic acid, 207,7 parts of 1,6-hexanediol
and 0.85 parts of tetrabutyl titanate as a catalyst were charged into a reactor equipped with a stirrer, a rectification column, and a methanol/water distillation condenser, and heated from 140°C to 220°C, and methanol and water produced as a result of the reaction were charged. Esterification and transesterification reactions were carried out while distilling the mixture out of the system. Four hours after the start of the reaction, the internal temperature reached 220°C, and the temperature reached 61.
2 parts of water and 102.4 parts of methanol were distilled off. The obtained reaction product was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and after adding 1 part of the antioxidant "Irganox i o io" and cooling it to 200°C, the temperature was increased from 200°C. The polycondensation reaction was carried out by gradually raising the temperature to 240°C and lowering the pressure from normal pressure to a high vacuum of 1 mm H (). In a total polycondensation reaction time of 7 hours, [η
]0.712 polynisrutylamide polymer was obtained.

The melting point of this polymer was 114°C.

Next, this polyesteramide is used as a sheath, and [η] 0
．． Using PET 64 as a core, a core/sheath composite fiber was spun using a conventional method at a core/sheath weight ratio of 50,750 to obtain a composite fiber with a single filament fineness of 3 denier, which was then cut into 5 lengths.

(2) Monofilament fineness 3 obtained in the above (1) as the binder fiber for nonwoven fabric production C
The same procedure as in Example 1 was carried out except that 10 parts of composite fibers having a denier and a fiber length of 5 mm were used. The results are shown in Table 1.

Example 4 (1) Production of binder fiber of C The polyesteramide polymer obtained in Example 1 (1) was spun alone to obtain a fiber having a single filament fineness of 2 denier, which was cut into a length of 5 mm.

(2) Production of fiber B Example 1 (2) except that dimethyl isophthalate was not used.
) to obtain a polyester polymer with [η] of 0.640. This was melt-spun to obtain a fiber with a single filament fineness of 1.1 denier and a birefringence index of 0.020, and then a length of 51 denier was obtained.
Cut to IIIN.

(3) Manufacture of nonwoven fabric 10 parts of the individual fibers obtained in (1) above with a single fiber fineness of 2 denier and a fiber length of 5 degrees, and the single fiber fineness obtained in (2) above of 1.1 denier.

30 parts of short polyester fibers with a birefringence index of 0.020 and a fiber length of 5ylI11 were mixed in a ratio of 60 parts of natural pulp, and paper was made in the same manner as in Example 1. The results are shown in Table 1.

Example 5 (1) Production of fiber B 776 parts of dimethyl terephthalate, 194 parts of dimethyl isophthalate, 558 parts of ethylene glycol, and 0.245 parts of manganese acetate tetrahydrate as a transesterification catalyst were added to a stirrer, a rectification column, The mixture was charged into a reactor equipped with a methanol distillation condenser and heated from 140°C to 220°C to carry out transesterification reaction while distilling methanol produced as a result of the reaction out of the system. 3 hours after the start of the reaction, the internal temperature was 240.
℃, and 320 parts of methanol was distilled out. here,
0.175 parts of trimethyl phosphate was added as a stabilizer, and 0.39 parts of antimony trioxide was added as a polycondensation catalyst.
4.85 parts of titanium dioxide were added as a matting agent. The reaction mixture was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and heated from 240°C to 2°C.
Gradually raise the temperature to 85℃ and from normal pressure to IIIH!
The polycondensation reaction was carried out without lowering the pressure to a high vacuum.

A polymer having [η] of 0.638 was obtained in a total polycondensation reaction time of 3 hours. This is melt spun to create a single yarn fineness of 1.1 denier.
A fiber with a birefringence of 0.009 was obtained and then cut to a length of 5 rnm.

(2) Production of nonwoven fabric Example 1 (1) Single yarn fineness of 3 denier and fiber length of 51
10 parts of iI+ composite fiber, single yarn fineness 1 obtained in (1) above
．． 30 parts of short polyester fibers having a denier of 1 denier, a birefringence of 0.009, and a fiber length of 5 cities were mixed with 60 parts of natural pulp, and paper was made in the same manner as in Example 1. Results first
Shown in the table.

Comparative example 1 Kuraray vinylon vPB101 as binder fiber C
(Single yarn fineness 1.3 denier, fiber length 4rnm) 10
Section, Kuraray Vinylon as fiber B VP B 103
(Single filament fineness 1 denier, fiber length 5 m + n) 30 parts and natural pulp 60 parts were mixed, dispersed in water to a fiber concentration of 0.03% by weight, and a square sheet made by Kumagai Riki Kogyo Co., Ltd. The paper was hand-made to 50g/r11' using a machine.

The tensile strength of this nonwoven fabric was measured in the same manner as in Example 1, and the dry strength was 3.36 kHz/15II.
It was high at II11, and the wet strength was 0.27k12 /
It was extremely low at 15 ROM.

Comparative Example 2 (1) 271.6 parts of dimethyl terephthalate, 38.8 parts of dimethyl isophthalate, and 7 parts of 12-aminododecanoic acid as raw materials for producing the binder fiber of C.
The same procedure as in Example 1 was carried out except that 31 parts and 207.7 parts of 1,6-hexanediol were used, and [η] 0.887
, a polynis sultylamide polymer with a melting point of 118°C was obtained.

Next, this polyesteramide is used as a sheath, and [η]0.
Using PET 64 as a core, a core/sheath composite fiber was spun using a conventional method at a core/sheath weight ratio of 50 to 150 to obtain a composite fiber with a single fiber fineness of 3 denier, which was cut into 5 lengths.

(2) Production of nonwoven fabric Single yarn fineness 3 denier and fiber length 5ITI obtained in (1) above
10 parts of II+ composite fiber, single yarn fineness 1.1 denier obtained in Example 1 (2), birefringence 0.012, fiber length 51I
30 parts of 1m polynystyl staple fiber and 6 parts of natural pulp
They were mixed at a ratio of 0 parts, and paper was made in the same manner as in Example 1.

The dry strength of this nonwoven fabric is 2.61kg/15mm
, the wet strength was 1.83 kg/15 tons.

Comparative Example 3 (1) Production of binder fiber of C 261.9 parts of dimethyl terephthalate 28.8 parts of dimethyl 2-isophthalate, 14.8 parts of dimethyl 5-sodium sulfoisophthalate, 731 parts of 12-aminododecanoic acid,
158.4 parts of 1,4-butanediol and 0.85 parts of tetrabutyl titanate as a catalyst were charged into a reactor equipped with a stirrer, a rectification column, and a methanol/water ratio condenser, and the temperature was raised from 140'C to 220°C. Esterification and transesterification reactions were carried out while heating and distilling methanol and water produced as a result of the reaction out of the system. Four hours after the start of the reaction, the internal temperature reached 180'C, and 61.2 parts of water and 102
．． 4 parts of methanol distilled off.

The obtained reaction product was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and after adding 1 part of the antioxidant "Ikanox 1010", the temperature was gradually raised from 180°C to 240°C. , 1 mm from normal pressure
The polycondensation reaction was carried out without lowering the pressure to the high vacuum of HCJ. A brown polyester amitopomer was obtained in a total polycondensation reaction time of 5 hours. This polymer [η1 is 0.809
, the melting point was 118°C. Next, using this polyesteramide as a sheath and using PET as a core with [η] of 0.64, core-sheath composite spinning was attempted using a conventional method at a core/sheath weight ratio of -50,150, or the sheath polymer decomposed rapidly and fibers were obtained. That was impossible.

Comparative Example 4 (1) Production of binder fiber of C 368 parts of decanedicarboxylic acid, 731 parts of 2-aminododecanoic acid, 207.7 parts of 1,6-hexanediol, and 0.85 parts of 1-butyl titanate as a catalyst were stirred. The mixture was charged into a reactor equipped with a distillation column, a rectification column and a water fraction condenser, and heated from 140'C to 220C to esterify the water produced as a result of the reaction without distilling it out of the system. The internal temperature reached 220°C 4 hours after the start of the reaction, and the temperature reached 11
8.8 parts of water or distillate. The obtained reaction product was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, one part of the antioxidant "Irganox 1010" was added, and after cooling to 200°C, the temperature was increased from 200°C to 240°C.
The polycondensation reaction was carried out by gradually raising the temperature to 100 ml and lowering the pressure from normal pressure to a high vacuum of 1 qq. A polynis sultylamide polymer having [η] of 0.843 was obtained in a total polycondensation reaction time of 6 hours. The melting point of this polymer was 116°C.

Next, this polyesteramide is used as a sheath, and [η]0.
64 PET as a core and core/sheath composite spinning at a core/sheath weight ratio of 50 to 150 using a conventional method to obtain composite 1 with a single yarn fineness of 3 denier.
Obtain the fibers and cut them into 5 mm lengths.

(2) Production of nonwoven fabric Single yarn fineness 3 denier obtained in (1) above, fiber length 51I1
m composite m1lf 10 parts, obtained in Example 1 (2), single yarn fineness 1.1 denier, birefringence 0.012, fiber length 5 m
30 parts of polynistil short fibers and 60 parts of natural pulp
A paper was made in the same manner as in Example 1. The dry strength of this nonwoven fabric was 2.45 kg/15 mm, and the wet strength was 1,72 kg/15 mm.

Comparative Example 5 (1) Production of Fiber B The polyester polymer obtained in Example 1 (2) was melt-spun and stretched to obtain a single fiber fineness of 1.1 denier and birefringence of 0.
054 fibers were obtained and then cut into 5 lengths.

(2) Production of nonwoven fabric Single yarn fineness 3 denier obtained in Example 1 (1), m female fitting 5I
10 parts of composite fiber of III11, single yarn fineness 1.1 denier obtained in (1) above, birefringence 0.054, m female tool 5
30 parts of short polyester fibers, and 6 parts of natural pulp
They were mixed at a ratio of 0 parts, and paper was made in the same manner as in Example 1.

The dry strength of this nonwoven fabric is 2.05kl (/15mm
The wet strength was 1,23 kg/15 n+m.

Comparative Example 6 (1) Production of fiber B The polyester polymer obtained in Example 1 (2) was melt-spun to produce a single fiber with a fineness of 1.1 denier and a birefringence index of 0.004.
fibers were obtained and then cut into lengths of 5 mm.

(2) Production of nonwoven fabric Single yarn fineness 3 denier and fiber length 51 obtained in Example 1 (1)
10 parts of composite fiber of I1m, single yarn fineness of 1 obtained in (1) above
, 1 denier, birefringence 0.004. 30 parts of short polyester fibers with a fiber length of 5 mm and 60 parts of natural pulp were mixed and paper was made in the same manner as in Example 1. The dry strength of this nonwoven fabric was 2.22 parts g 715 mm, and the wet strength was 1.45 kg/15 rnm.

Comparative Example 7 (2) Production of fiber B The mixture was charged into a reactor equipped with a methanol distillation condenser, heated from 140°C to 220°C, and transesterification was carried out while methanol produced as a result of the reaction was distilled out of the system. 3 hours after the start of the reaction, the internal temperature was 240.
℃ and distill off 320 parts of methanol. here,
0.175 parts of 1-helimethyl phosphate was added as a stabilizer, and 0.13 parts of antimony trioxide was added as a polycondensation catalyst.
After adding 9 parts, 4.85 parts of titanium dioxide as a matting agent.
Added a section. The reaction mixture was transferred to a reactor equipped with a stirrer and a glycol distillation condenser, and the temperature was gradually raised from 240°C to 285°C, and the temperature was increased from 1 mm l to 1 mm l.
A polycondensation reaction was carried out while lowering the pressure to -1 g of high vacuum. A polymer with [η] of 0.641 was obtained in a total polycondensation reaction time of 3 hours. This was melt-spun to obtain a fiber with a single filament fineness of 1.1 denier and a birefringence of 0.008, which was then cut into a length of 5 mm.

(2) Production of nonwoven fabric Single yarn fineness 3 denier obtained in Example 1 (1), m separation technique 5
10 parts of composite fiber of mm, single yarn fineness obtained in (1) above: 1.
30 parts of polynystyl short fibers having a denier of 1 denier, a birefringence of 0.008, and a fiber length of 5 strands and 60 parts of natural pulp were mixed and paper was made in the same manner as in Example 1. The dry strength of this nonwoven fabric was 2.01 kg/15 mm, and the wet strength was 1.41 kg/15 rnm.

Comparative Example 8 (1) Production of fiber B The polyester polymer obtained in Example 1 (2) was melt-spun to obtain a fiber with a single filament fineness of 1.5 denier and a birefringence of 0.014, and then a fiber with a length of 51iI11 Do not disconnect.

(2) Production of nonwoven fabric Single yarn fineness 3 denier obtained in Example 1 (1), m female tool 51
1 ml of I1 conjugate fiber 10 parts, single fiber fineness 1.5 denier obtained in (1) above, birefringence 0.014, fiber length 5 rnm
30 parts of short polyester fibers were mixed with 60 parts of natural pulp, and paper was made in the same manner as in Example 1. The dry strength of this nonwoven fabric was 2.98 to 2/15, and the wet strength was 2.09 kg/15.

#Ken 4A Yukigami Mibantaku Procedures Amendment 1. Indication of the case Patent Application No. 1983 No. 2, Name of the invention Method for manufacturing wet-processed non-woven fabric 3, Person making the amendment Relationship to the case Patent applicant (Change of indication due to residence indication) Daiso v. J. Ura Chuo Omoto-cho 1-6-7 No. (3.00) Teijin Ltd. 4, Agent 2-1-1 Uchisaiwai-cho, Chiyoda-ku (
Iino Building) 5. Subject of amendment 1) The scope of claims is as shown in the attached sheet.

2) Statement on page 6, line 3 of the specification “...1,5
−Pentadiol・・・・・・” to “・・・・・・1,
5-bentanediol...'' is corrected.

3) Statement on page 6, line 14 of the specification “...1,
5-pentangio-" is corrected to "...1,5-pentangio-".

4) Description on page 9, line 15 of the specification [ntadiol...
...Correct J to "ntandiol...".

5) Statement on page 8, line 16 of the specification [...1,
2-..." is corrected to "...12-...".

6) Statement on page 8, line 17 of the specification “...1,
1-..." is corrected to "...11-...".

7) The statement on page 9, line 4 of the specification is corrected as "...Polyesteramide...J is 1...Polyesteramide...".

8) Statement on page 9, line 16 of the specification “...1,
2-..." is corrected to "...12-...".

9) Statement on page 9, line 17 of the specification “...11
-...J is corrected as "...11-...".

10) The statement "...bromnaphthalene..." on page 11, line of the specification is corrected to "...bromnaphthalene...".

11) Statement on page 11, line 16 of the specification “...
, 3 denier...'' to [...1.3-
"..." I corrected myself.

12) Statement on page 15, line 14 of the specification [...
"C binder..." is corrected to "...C binder...".

13) Statement on page 16, line 16 of the specification “...
Insert the following statement after “methanol is...”.

"Distilled. The resulting reaction product was mixed with a stirrer and glycol." 14) After the statement "...dispersed,..." on page 18, line 5 of the specification, the following statement was added. insert.

"Hand-made paper to 50 g/rrr using Kumagai Riki Kogyo's square sheet machine. Then, the temperature of this nonwoven fabric was controlled at 120°C." 15) Description on page 20, line 10 of the specification: "...
Correct "12-amino" to "...12-amino".

16) The description on page 27, line 6 of the specification [...bomber...] has been changed to "...polymer..."
"..." I corrected myself.

17) Statement on page 16, line 12 of the specification “...
Polyester Rural Tellamide...''
...Polyesteramide..." I corrected it.

18) The statement "Rutilamide..." on page 19, line 15 of the specification is corrected to "Tylamide...".

19) The statement "...polyesteramide...J" on page 21, line 7 of the specification is corrected to "...polyesteramide...".

20) The statement [...polynisrutylamide...] on page 25, line 9 of the specification has been corrected to "...polyesteramide..." do.

21) Statement on page 28, line 10 of the specification “...
Polynisruthylamide..." is changed to "...
“Polyesteramide…” I corrected myself.

Claims of the Attached Patent A method for producing a wet-laid nonwoven fabric comprising mixing natural pulp (A), polyester fibers (B), and binder fibers (C) and making wet paper, wherein the polyester fibers (B) contain 0 to 20 mol% of isophthalic acid. It is a polymerized polyethylene terephthalate short fiber with a birefringence of 0.006 to 0.03 and a single filament fineness of 1.3 denier or less, and the binder m fiber (C) is terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid metal salt, 1
, 5-bentanediol and/or 1,6-hexanediol, aminododecanoic acid and/or aminoundecanoic acid, and whose adhesive component is a polyesteramide having a melting point of 120° C. or less, which is made of pulp A. A method for producing a wet-laid nonwoven fabric, characterized in that the weight ratio of /polyester fiber B/binder fiber C is 50 to 80/15 to 4515 to 15.

Continuation-I (Method) % formula % 1. Indication of the case 2. Name of the invention Method for manufacturing wet-laid nonwoven fabric 3. Person making the amendment Relationship to the case Patent applicant 1-6-7 Minamihonmachi, Chuo-ku, Osaka-shi, Osaka Prefecture No. (300) Teijin Ltd. 4, Agent 2-1 Uchisaiwai-cho, Chiyoda-ku, Tokyo
No. 1 (Iino Building) 5. Date of amendment order December 26, 1999 1) The statement [α-bromnaphthalin...] on page 11, line 13 of the specification was replaced with "α-bromnaphthalene..." Bromnaphthalene...
"..." I corrected myself.

2) Statement on page 16, lines 6-7 of the specification “...
Insert the following description in place of "Distillate condenser...".

"Distilled. The resulting reaction product was transferred to a stirrer and a glycol distillation condenser."・・・Polyesteramide polymer” is corrected.

4) The description in page 21, line 7 of the specification “...polynis sultylamide polymer...” has been changed to “...”
``Polyesteramide polymer...'' is corrected.

that's all

Claims (1)

[Claims] In a method for producing a wet-laid nonwoven fabric in which a natural pulp (A), a polyester fiber (B), and a binder fiber (C) are mixed and wet-laid paper is made, the polyester fiber (B) has a birefringence of 0.0. 006 to 0.03 Polyethylene terephthalate short fibers with a single yarn fineness of 1.3 denier or less, and the binder fiber (C) is terephthalic acid, isophthalic acid, 5-sulfoisophthalic acid metal salt, 1
, 5-pentadiol and/or 1,6-hexanediol, aminododecanoic acid and/or aminoundecanoic acid, and whose adhesive component is a polyesteramide having a melting point of 120°C or less, which is made of pulp A.
/Polyester fiber B/Binder fiber C weight ratio is 5
0 to 80/15 to 45/5 to 15. A method for producing a wet-laid nonwoven fabric.