CN1572920A - Nonwoven fabric made from polyformaldehyde resin and its making method - Google Patents

Abstract

The invention provides a non-woven fabric made of a polyoxymethylene resin having a good spinning property and stretching property, and excellent in mechanical properties. This non-woven fabric made from the polyoxymethylene resin consisting of a polyoxymethylene copolymer containing 1.5-10 mol specific oxyalkylene unit per 100 mol oxymethylene unit in a polymer chain consisting mainly of the recurring oxymethylene unit, and having 1-100 g/10 min melt index (at 190[deg.]C and 2,160 g loaded weight).

Description

Nonwoven fabric made from polyformaldehyde resin and manufacture method thereof

Technical field

The present invention relates to non-weaving cloth and the manufacture method thereof made by specific polyacetal copolymer.

Background technology

Known acetal resin is good at aspects such as degree of crystallinity height, rigidity, intensity, chemical-resistant, solvent resistance, alkali resistances.And,, be widely used in the organ field of automobile, motor mainly as the injection molded material because crystallization rate is fast, molding cycle is short.

Though acetal resin is the resin with so many good characteristics, because degree of crystallinity height and crystallization speed are fast, there is certain restriction in the processing and forming Application for Field beyond injection mo(u)lding.

Wherein, the non-weaving cloth of being made by acetal resin is needed in the extensive use field of the performance good characteristics as mentioned above that acetal resin had, but because aforesaid crystallization characteristic, cause lacking stringiness, spinnability, draftability etc., the fiber of stability property can not be obtained to have by melt spinning etc. industrially, non-weaving cloth can not be made.

At this problem, proposition use melt viscosity in non-weaving cloth is 100～500 polyacetal resin (the flat 8-113823 communique of open patent (claim 1, embodiment)).

And, in the document, being called as the characteristic of melt viscosity, its assay method is documented in [0009] hurdle, and it is commonly referred to as melt index (MI) (perhaps melt flow index), is the characteristic of expression Resin Flow.Because it is imprecise to be called melt viscosity, hereinafter referred to as melt index (MI), subsidiary in case of necessity the note.This melt index (MI) is big, means that the molecular weight of resin is little, truly melt viscosity is low.

Summary of the invention

According to the flat 8-113823 communique of above-mentioned open patent (claim 1, invention disclosed embodiment), only be conceived to the melt index (MI) (being called melt viscosity in the literature) of polyacetal resin, specifically as seen from this embodiment, oxirane as comonomer is 2 weight % (relative 100 moles of formaldehyde unit, oxygen alkylidene unit is about 1.4 moles), prepare the only different various polyacetal resins of melt index (MI), melt index (MI) demonstrates effect at the polyacetals of particular range (promptly 100～500).

Yet, even compare with polyacetal resin with this scope melt index (MI) in addition, the polyacetal resin of melt index (MI) in this scope shown relative effect, only adjust the as above polyacetal resin of melt index (MI) but adopt, stringiness during the processing non-weaving cloth and spinnability lack practicality not enough.

In addition, the flat 8-113823 communique of the above-mentioned open patent of present inventor's tracking test (claim 1, when the melt index (MI) (being called melt viscosity in the literature) of record is the preparation of 100～500 polyacetal resin embodiment), the molecular weight of the polyacetal resin of this melt index (MI) is little, in that truly melt viscosity is low, so its preparation is difficulty very, can not be in industrial manufacturing.And, the polyacetal resin of this low melting viscosity lacks melt processable, usually, in the manufacturing of polyacetal resin (copolymer), realize unstable terminal decomposition removal processing and mixed stabilizer and use the stabilization processes of extruder melting mixing very difficult by the melting mixing of carrying out as conventional method.Also have, because it is molecular weight is little, also satisfied inadequately at aspects such as heat endurance and mechanical properties.

Therefore, only adjusting melt index (MI), to use melt index (MI) be 100～500 polyacetals for the flat 8-113823 communique of characteristic open patent only (claim 1, embodiment) in disclosed non-weaving cloth have aforesaid problems.

The objective of the invention is to solve above-mentioned problem, the good non-weaving cloth of being made by the specific acetal resin that improves in aspects such as mechanical performance be provided, with and manufacture method efficiently.

Present inventors study in order to achieve the above object with keen determination, found that, by using the specific polyacetal copolymer of crystallization control characteristic, flowability etc., can obtain spinnability, draftability is good, mechanical property is good non-weaving cloth, thereby finish the present invention.

Promptly the present invention relates to the polyformaldehyde resin made Nonwovens, it is included in the formaldehyde repetitive is to contain (190 ℃ of the oxygen alkylidene unit of following general formula (1) expression that every 100mol formaldehyde unit is 1.5～10mol and melt index (MI)s in the polymer chain that becomes of dominant shape, load 2160g) be the polyacetal copolymer that 1～100g/10 divides, and the non-weaving cloth manufacture method of using above-mentioned polyacetal copolymer.

(in the formula, R ₁, R ₂Be selected from the alkyl of hydrogen, carbon number 1～8, the organic group that contains the alkyl of carbon number 1～8, phenyl, contain the organic group of phenyl, R ₁, R ₂Can be identical, also can be different.M represents 2～6 integer.)

In addition, the invention provides the purposes that above-mentioned acetal resin is used for non-weaving cloth.

The specific embodiment

Below, the present invention is described in detail.Nonwoven fabric made from polyformaldehyde resin of the present invention, as mentioned above, it is characterized in that: it is included in the formaldehyde repetitive is in the polymer chain of dominant shape one-tenth, every 100mol formaldehyde unit contains the oxygen alkylidene unit of the above-mentioned general formula of 1.5～10mol (1) expression, and melt index (MI) (190 ℃, load 2160g) is the polyacetal copolymer that 1～100g/10 divides.

In this polyacetal copolymer that the present invention uses, the ratio of the oxygen alkylidene unit of general formula (1) expression, being preferably every 100mol formaldehyde unit is 2～8mol, preferred especially every 100mol formaldehyde unit is 2～5mol.If the ratio of the oxygen alkylidene unit of general formula (1) expression becomes very few, the crystallization rate of polyacetal copolymer will accelerate, and not only the fracture of wire during spinning has increased, thereby and since after the spinning soon degree of crystallinity increase draftability also descended.On the contrary, if the ratio of the oxygen alkylidene unit of general formula (1) expression becomes too much, the mechanical property of polyacetal copolymer etc. can reduce.

In addition, in the polyacetal copolymer that uses among the present invention, melt index (MI) is preferably 2.5～90g/10 branch, preferred especially 5～80g/10 branch.

And the melt index (MI) of defined (MI) is according to ASTM D-1238 here, the value of measuring under 190 ℃, the load of 2160g.

The excessive polyacetal copolymer of melt index (MI) (MI) is difficult in industrial manufacturing stably, also have, low molecular weight causes melt viscosity to become low, so in the manufacturing of polyacetal copolymer, remove processing and mixed stabilizer and use melt processable in the processes such as stabilization processes of the extruder melting mixing non-constant that becomes by the unstable terminal decomposition of the melting mixing of carrying out as conventional method.And, because low molecular weight, heat endurance and mechanical property variation, easy fracture of wire when spinning and stretching, it is unstable that the manufacturing of fiber becomes.On the contrary, use the too small polyacetal copolymer of melt index (MI) (MI), because melt viscosity is too high, thereby load increases and extrudes the difficulty that becomes during spinning.

Restriction especially of manufacture method to the polyacetal copolymer as mentioned above that uses among the present invention, generally can use trioxane and as the cyclic ether compound or the cyclic formals compound of comonomer, the main cationic polymer catalyst that adopts makes it the method for bulk polymerization and obtains.As polyplant, can use known devices such as batch type, continous mode arbitrarily.Here, the introducing ratio of the oxyalkylene unit of above-mentioned general formula (1) expression can be adjusted according to the amount of the comonomer of copolymerization, in addition, the chain-transferring agent that melt index (MI) (MI) uses in the time of can be according to polymerization, for example the addition of dimethoxym ethane etc. is adjusted.

As cyclic ether compound that is used for comonomer or cyclic formals compound, can enumerate oxirane, expoxy propane, epoxy butane, chloropropylene oxide, epibromohydrin, styrene oxide, oxetanes, 3,3-two (chloromethyl) oxetanes, oxolane, ト リ オ キ セ パ Application, 1, the 3-dioxolanes, the propylene glycol formal, the diethylene glycol (DEG) formal, the triethylene glycol formal, 1,4-butanediol formal, 1,5-pentanediol formal, 1,6-hexylene glycol formal etc., optimization ethylene oxide wherein, 1, the 3-dioxolanes, the diethylene glycol (DEG) formal, 1,4-butanediol formal.In addition, the polyacetal copolymer that uses among the present invention can have branch or cross-linked structure.

In the present invention in the polyacetal copolymer of Shi Yonging, the oxygen alkylidene unit of representing by the above-mentioned formula (1) of this comonomer formation preferably is evenly dispersed in the strand of polyacetal copolymer very much, the oxygen alkylidene unit of above-mentioned general formula (1) expression, the ratio of the unit of 2 or above connection are preferably the 5mol% of whole oxygen alkylidene units or following.

The polyacetal copolymer that obtains by polymerization is carried out after washing, the drying of removal, the polymer of inactivation processing, the unreacted monomer of catalyst, stabilization processes of unstable distal portion etc., carry out stabilization processes by mixing various stabilizing agents etc. again, can throw in application.As representational stabilizing agent, can recommend hydroxide, inorganic salts, carboxylate of hindered phenol compound, nitrogen-containing compound, alkali metal or alkaline-earth metal etc.

And, in the scope of not damaging the object of the invention, as required, can be in the polyacetal copolymer that the present invention uses, add the common additives of a kind or 2 kinds or above relatively hot plastic resin, for example colouring agent such as dyestuff, pigment, lubricant, nuclear agent, releasing agent, antistatic additive, surfactant or high-molecular organic material, inorganic or organically fibrous, sheet, granular filler etc.

Then, the manufacture method to the non-weaving cloth that uses aforesaid polyacetal copolymer describes.

For the processing method of non-weaving cloth, in case after can using spun-bond process, meltblown staple fibre or long fiber filature,, limit especially by the manufacture method etc. of utilizing any method binding fiber or tangling the non-weaving cloth of fiber.Here, under the situation of meltblown, the preferred melt index (MI) that uses is that 20～100g/10 divides in the above-mentioned melt index (MI) (MI), more preferably 30～90g/10 branch.Also have, under the situation of spun-bond process and staple fibre non-weaving cloth, preferably using melt index (MI) is that 1～30g/10 divides, more preferably 5～20g/10 branch.

Limit especially as the binding fiber or the method for tangling fiber, can use heat fused, adhesive bonding, by liquefied gas stream the methods such as acupuncture of complexing, employing special shape pin.For the legal situation of hot melt,, can expect not only to enlarge the fusion temperature scope, and increase bonding strength by mixing low-melting polymer or in outer (crust), using low-melting polymer to form skin-core structure.

In addition, by the WEB that will form by monofilament etc. as base material, the acupuncture staple fibre also tangles staple fibre on WEB, the non-weaving cloth sheet that makes like this, because the mechanical strength of cloth sheet direction is big and have the ventilation water flowing, and is also very wide in industrial range of application as the squezzing filter with conveying function.

Another characteristics of the present invention are: by using specific polyacetal copolymer to make in the conventional spinning manufacturing process as the fiber of non-weaving cloth constituent, because low stress is easy to molecularly oriented.Because the degree of orientation of molecule uprises, thereby gives intensity, toughness to fiber, the texture and the mechanical properties of non-weaving cloth had a significant impact.

Non-weaving cloth of the present invention carries out the wide-angle x-ray diffraction to the fiber as its constituent to be measured, the degree of orientation of preferably calculating be 50% or more than, the use of above-mentioned specific polyacetal copolymer makes it become possibility.Under the too small situation of the degree of orientation, constitute the characteristic that fiber enbrittles, difficulty thereby the crisp actual use of fiber becomes.Here, in following formula, provided the ordered orientation parameter, S has been calculated as the degree of orientation.

$S\&equiv;\frac{1}{2}[3<{\cos }^2\mathrm{\&phi;}>-1]$

$<{\cos }^2\mathrm{\&phi;}>=\frac{{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}I\left(\mathrm{\&phi;}\right){\cos }^2\mathrm{\&phi;}\sin \mathrm{\&phi;d\&phi;}}{{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}I\left(\mathrm{\&phi;}\right)\sin \mathrm{\&phi;d\&phi;}}$

φ: the angle that molecule chain rivet and fiber axis form

, can at random set according to purposes, and there is no particular limitation as the diameter of the fiber of non-weaving cloth constituent in the present invention, for example, the fiber from 2dtex to the 50dtex scope can be described as and is suitable for non-weaving clothization.

Non-weaving cloth with the acetal resin manufacturing of the present invention effectively utilizes the excellent characteristic of its high strength, high elasticity rate, solvent resistance, heat resistance, friction wear characteristic and has various uses.For example, can be used for squezzing filter, building sheet, construction material and other various uses.

Embodiment

Below, by embodiment the present invention is specifically described, but the present invention is not limited to these embodiment.

Embodiment 1～10

Use is had the chuck of logical heat (cold) medium by the outside, and the cross section has the tube of 2 overlapping shapes of circular portion and has the continous mode hybrid reaction machine of the rotating shaft formation of blade, 2 rotating shafts that have blade rotate with 150rpm separately, add liquid trioxane simultaneously, cyclic ether or cyclic formals (1 as comonomer, the 3-dioxolanes, 1,4-butanediol formal, ethylene glycol acetal), in the polymerisation machine, provide dimethoxym ethane also to provide 50ppm the catalyst boron trifluoride of (with respect to whole monomers) simultaneously more continuously as molecular weight regulator, carry out bulk polymerization, the polymer of oxygen alkylidene unit amount shown in the preparation table 1.Pass through pulverizer apace from the product that the polymerisation machine is discharged, simultaneously, join in 60 ℃ of aqueous solution that contain 0.05 weight % triethylamine, make catalysqt deactivation.After passing through separation, washing, drying again, obtain thick polyacetal copolymer.

Then, with respect to the thick polyacetal copolymer of this 100 weight portion, (3-(3 to add the aqueous solution of 4 weight portions, 5 weight % triethylamines and 0.3 weight portion pentaerythrite base-four, 5-two-tert-butyl-hydroxy phenyl) propionic ester), thus remove l fraction by biaxial extruder 210 ℃ of following melting mixing.

In the 100 weight portion acetal resins that obtain by said method, add 0.03 weight portion (3-(3 as the pentaerythrite base-four of stabilizing agent, propionic ester) and the melamine of 0.15 weight portion 5-two-tert-butyl-hydroxy phenyl), 210 ℃ of following melting mixing, obtain granular acetal resin by biaxial extruder.

Use the polymer of gained, make non-weaving cloth by following method.

(1) meltblown

Use resulting polymers, it by the machine barrel design temperature 200 ℃ extrusion shaper fusion plastification resin, and with gear pump metering, under 225 ℃ nozzle temperatures, 200 ℃ hot blast temperature according to quantitatively melting and spraying, have suction carry out on the net continuous stacked and collect simultaneously.Then, thus the sandwich by the acupuncture gained makes the fiber obvolvent make non-weaving cloth.

(2) spun-bond process

Use resulting polymers, be 200 ℃ extrusion shaper fusion plastification resin and measure by the machine barrel design temperature with gear pump, under 225 ℃ nozzle temperature, carry out spunbondly, collect and make fiber web continuously, thereby make non-weaving cloth by acupuncture obvolvent fiber then.

(3) staple fibre non-weaving cloth

Using resulting polymers, is 200 ℃ extrusion shaper fusion plastification resin and with the gear pump metering by the machine barrel design temperature, carries out melt spinning under 225 ℃ nozzle temperatures, 200 ℃ hot blast temperature, obtains staple fibre by the length that cuts into 35mm.In the combing mode staple fibre that obtains is opened fibre to make fiber web, then, obtain non-weaving cloth by carrying out obvolvent with acupuncture.

Comparative example 1～4

Except the addition of the use amount that changes comonomer or dimethoxym ethane, operate equally with embodiment, prepare oxygen alkylidene unit amount as shown in table 1 or melt index (MI) and be the acetal resin beyond the present invention stipulates, similarly obtain non-weaving cloth.The results are shown in Table 1.

Comparative example 5

Use oxirane as comonomer, the amount of preparation oxygen alkylidene unit and melt index (MI) are the acetal resins beyond the present invention stipulates, similarly obtain non-weaving cloth.The results are shown in Table 1.

And the evaluation criterion in the embodiment comparative example etc. is carried out according to following.

[melt index (MI) (MI) mensuration]

Abide by ASTMD-1238, under 190 ℃, the load of 2160g, measure.

[polymer composition analysis]

Employed polymer dissolution in the evaluation of physical property in hexafluoroisopropanol d2, is carried out ¹H-NMR measures.Undertaken quantitatively by peak area corresponding to each unit.

[degree of orientation]

Use wide-angle x-ray diffraction instrument (motor system Rint-1400 of science),, measure by the two-dimensional scattering figure that takes transmission beam method with X ray (Cu-K α) pin hole ray and dull and stereotyped imaging plate (IP) by the monochromatization of Ni filter.Calculate by following formula.

$S\&equiv;\frac{1}{2}[3<{\cos }^2\mathrm{\&phi;}>-1]$

$<{\cos }^2\mathrm{\&phi;}>=\frac{{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}I\left(\mathrm{\&phi;}\right){\cos }^2\mathrm{\&phi;}\sin \mathrm{\&phi;d\&phi;}}{{\&Integral;}_0^{\frac{\mathrm{\&pi;}}{2}}I\left(\mathrm{\&phi;}\right)\sin \mathrm{\&phi;d\&phi;}}$

φ: the angle that molecule chain rivet and fiber axis form

[processability judgement]

The non-weaving cloth processability is judged.

Table 1

	Polymerizing condition		Polymer is formed			Non-weaving cloth is made the result
									The comonomer kind	Dimethoxym ethane amount (ppm)	Oxygen alkylidene unit	Relative 100mol formaldehyde (mol)	MI (g/10min)	The non-weaving cloth manufacture method	Constitute the fiber orientation degree	Processability is judged
	Embodiment 1	?DO	?450～650	(CH 2CH 2O)	2.2	?5	The staple fibre non-weaving cloth	0.87									Well
Embodiment 2									?DO	?500～700	(CH 2CH 2O)	2.2	?9	The staple fibre non-weaving cloth	0.87	Well
	Embodiment 3	?DO	?500～700	(CH 2CH 2O)	2.2	?9	Spunbond	0.78									Well
Embodiment 4									?DO	?1000～1500	(CH 2CH 2O)	2.2	?25	Melt and spray	0.75	Viscosity height a little
	Embodiment 5	?DO	?1700～1900	(CH 2CH 2O)	2.2	?45	Melt and spray	0.72									Well
Embodiment 6									?DO	?500～700	(CH 2CH 2O)	4.3	?9	The staple fibre non-weaving cloth	0.87	Well
	Embodiment 7	?DO	?500～700	(CH 2CH 2O)	5.7	?9	The staple fibre non-weaving cloth	0.83									Well
Embodiment 8									?EGF	?500～700	(CH 2CH 2OCH 2CH 2O)	2.2	?9	The staple fibre non-weaving cloth	0.85	Well
	Embodiment 9	?BDF	?500～700	(CH 2CH 2CH 2CH 2O)	2.2	?9	The staple fibre non-weaving cloth	0.80									Well
Embodiment 10									?DO	?500～700	(CH 2CH 2O)	2.2	?9	The staple fibre non-weaving cloth	0.62	Well
	Comparative example 1	?DO	?500～700	(CH 2CH 2O)	0.48	?9	The staple fibre non-weaving cloth	0.5									Fracture of wire mostly occurs
Comparative example 2									?DO	?500～700	(CH 2CH 2O)	1.2	?9	The staple fibre non-weaving cloth	0.64	Fracture of wire mostly occurs
	Comparative example 3	?DO	?2800～3200	(CH 2CH 2O)	2.2	?150	Melt and spray	-									Fracture of wire mostly occurs to process and interrupts
Comparative example 4									?DO	?0	(CH 2CH 2O)	2.2	?0.8	The staple fibre non-weaving cloth	-	Because viscosity is excessive can not spinning
	Comparative example 5	?DO	?4000～5000	(CH 2CH 2O)	1.35	?200	Melt and spray	0.5									Processing is interrupted because the too small fracture of wire of viscosity mostly occurs

(notes)

DO:1, the 3-dioxolanes

BDF:1,4-butanediol formal

EGF: ethylene glycol acetal

EO: oxirane

Claims (15)

1. nonwoven fabric made from polyformaldehyde resin, it is included in the formaldehyde repetitive is in the polymer chain of dominant shape one-tenth, contain every 100mol formaldehyde unit and be (190 ℃ of the oxygen alkylidene unit of the following general formula of 1.5～10mol (1) expression and melt index (MI)s, load 2160g) is the polyacetal copolymer that 1～100g/10 divides

In the formula, R ₁, R ₂Be selected from the alkyl of hydrogen, carbon number 1～8, the organic group that contains the alkyl of carbon number 1～8, phenyl, contain the organic group of phenyl, R ₁, R ₂Can be identical, also can be different, m represents 2～6 integer.

2. nonwoven fabric made from polyformaldehyde resin as claimed in claim 1 wherein contains the above-mentioned oxygen alkylidene unit that every 100mol formaldehyde unit is 2～8mol in the polyacetal copolymer.

3. nonwoven fabric made from polyformaldehyde resin as claimed in claim 1 wherein contains the above-mentioned oxygen alkylidene unit that every 100mol formaldehyde unit is 2～5mol in the polyacetal copolymer.

4. as each described nonwoven fabric made from polyformaldehyde resin of claim 1～3, wherein polyacetal copolymer has the melt index (MI) that 2.5～90g/10 divides.

5. as each described nonwoven fabric made from polyformaldehyde resin of claim 1～3, wherein polyacetal copolymer has the melt index (MI) that 5～80g/10 divides.

6. as each described nonwoven fabric made from polyformaldehyde resin of claim 1～3, wherein polyacetal copolymer has branch or cross-linked structure.

7. as each described nonwoven fabric made from polyformaldehyde resin of claim 1～3, it is 50% or the above degree of orientation that the fiber that wherein constitutes non-weaving cloth has as the axial degree of orientation of fiber that records by the wide-angle x-ray diffraction.

8. the manufacture method of nonwoven fabric made from polyformaldehyde resin, it is characterized in that: when making nonwoven fabric made from polyformaldehyde resin, as acetal resin, use in the polymer chain that becomes as dominant shape with the formaldehyde repetitive, the oxygen alkylidene unit and the melt index (MI) (190 ℃, load 2160g) that contain every 100mol formaldehyde unit and be following general formula (1) expression of 1.5～10mol are the polyacetal copolymer that 1～100g/10 divides, and form fiber, then in conjunction with or tangle this fiber

In the formula, R ₁, R ₂Be selected from the alkyl of hydrogen, carbon number 1～8, the organic group that contains the alkyl of carbon number 1～8, phenyl, contain the organic group of phenyl, R ₁, R ₂Can be identical, also can be different, m represents 2～6 integer.

9. as the manufacture method of nonwoven fabric made from polyformaldehyde resin as described in the claim 8, wherein contain the above-mentioned oxygen alkylidene unit that every 100mol formaldehyde unit is 2-8mol in the polyacetal copolymer.

10. as the manufacture method of nonwoven fabric made from polyformaldehyde resin as described in the claim 8, wherein contain the above-mentioned oxygen alkylidene unit that every 100mol formaldehyde unit is 2-5mol in the polyacetal copolymer.

11. as the manufacture method of claim 8～10 nonwoven fabric made from polyformaldehyde resin as described in each, wherein polyacetal copolymer has the melt index (MI) that 2.5～90g/10 divides.

12. as the manufacture method of claim 8～11 nonwoven fabric made from polyformaldehyde resin as described in each, wherein polyacetal copolymer has the melt index (MI) that 5～80g/10 divides.

13. as the manufacture method of claim 8～10 nonwoven fabric made from polyformaldehyde resin as described in each, wherein polyacetal copolymer has branch or cross-linked structure.

14. manufacture method as claim 8～10 nonwoven fabric made from polyformaldehyde resin as described in each, wherein using polyacetal copolymer to form to have as the fiber axis direction degree of orientation that records by the wide-angle x-ray diffraction is 50% or the fiber of the above degree of orientation, then in conjunction with or tangle this fiber.

15. as the purposes of each described acetal resin of claim 1～3 in non-weaving cloth.