WO2015115633A1

WO2015115633A1 - Fiber

Info

Publication number: WO2015115633A1
Application number: PCT/JP2015/052790
Authority: WO
Inventors: 小野　雄平; 正宏岩井; 俊介兼松; 信一郎庄司; 竜司野々川; 山本　智義
Original assignee: 帝人株式会社
Priority date: 2014-01-28
Filing date: 2015-01-27
Publication date: 2015-08-06

Abstract

The present invention provides, with little process pollution, a fiber which when put in high-temperature water, can retain the weight of a resin and the shape for a certain period and be thereafter degraded. A core-sheath type composite fiber composed of a core part and a sheath part, wherein: a resin composition (C) which comprises both a resin (A) that exhibits autocatalysis and a hydrolysis suppressor (B) is positioned in the core part; and a resin composition (D) which comprises a resin (A') that exhibits autocatalysis and which is substantially free from the hydrolysis suppressor (B) is positioned in the sheath part.

Description

fiber

The present invention relates to a fiber having a resin having an autocatalytic action as a main component and having excellent shape retention and hydrolysis resistance in high-temperature hot water, and a production method with less process contamination.

In recent years, for the purpose of protecting the global environment, resins that are easily decomposed in a natural environment have attracted attention and have been studied all over the world. Biodegradable polymers represented by aliphatic polyesters such as polylactic acid, polyglycolic acid, poly (3-hydroxybutyrate), and polycaprolactone are known as resins that are easily decomposed in a natural environment.
In particular, polylactic acid is a polymer material that is highly biosafe and environmentally friendly because it uses lactic acid obtained from plant-derived raw materials or derivatives thereof as raw materials. Therefore, the use as a general-purpose polymer is examined, and the use as a film, a fiber, an injection molded product, etc. is examined.
Recently, paying attention to the easy decomposability of such a resin, its use in oil field drilling technology has been studied (Patent Documents 1 to 3). In this application, it is required to quickly decompose after holding the weight and shape of the resin for a certain period in hot water (see FIG. 1). However, aliphatic polyesters and the like are generally poor in hydrolysis resistance and can be used up to a medium temperature of about 120 ° C., but quickly decompose in high-temperature hot water (see FIG. 2). The problem is that the desired performance cannot be exhibited.
On the other hand, in order to maintain the weight and shape of the resin in a high temperature region for a longer time, it is possible to use a resin having a slow decomposition such as an aromatic polyester, but it is necessary to control the start time of the decomposition.
Regarding the high temperature, 127 ° C to 193 ° C described in the report “US SHARE GAS” published by Halliburton in 2008, and “Petroleum / Natural” published by the Japan Oil, Gas and Metals National Corporation. Various definitions such as 149 ° C. or higher described in “Gas Review” 2002/5 are made, and it is generally considered that the temperature is higher than 125 ° C. to 150 ° C. In the present invention, a temperature higher than 135 ° C. is defined as a high temperature.
On the other hand, in order to improve hydrolysis resistance of aliphatic polyesters, etc., hydrolysis modifiers such as carbodiimide compounds are used, and the hydrolysis is suppressed by sealing the acidic groups generated by the initial stage and decomposition in the resin. Has already been proposed (Patent Documents 4 and 5).
For example, an acidic group such as a carboxyl group generated by hydrolysis of polyester serves as an autocatalyst and promotes hydrolysis. Therefore, by immediately sealing this with a carbodiimide compound or the like, it can be used in a humid heat environment of about 50 to 120 ° C. Improvement of hydrolysis resistance has been confirmed.
In the past studies, the present inventors used a specific hydrolysis inhibitor characterized by water resistance and reactivity with acidic groups, so that carboxyl groups and the like can be obtained in hot water at a high temperature of 135 ° C. or higher. It has been found that end groups having autocatalytic action can be sealed.
On the other hand, there is a problem that a compound having an isocyanate group is liberated with a reaction in which the carbodiimide compound is bonded to the terminal of the polymer compound, a unique odor of the isocyanate compound is generated, and the process is contaminated. In order to solve this problem, there is a cyclic carbodiimide compound that does not liberate an isocyanate compound. However, this cannot achieve both the water resistance and the reactivity with an acidic group for effectively functioning at a high temperature of 135 ° C. or higher. (Patent Document 6). Further, like the isocyanate compound, the carbodiimide compound itself leaks out during processing, and the process is contaminated.

JP 2009-114448 A US Pat. No. 7,267,170 US Pat. No. 7,228,904 JP 2012-012560 A JP 2009-173582 A WO2010 / 071213 pamphlet

An object of the present invention is to provide a fiber that decomposes after maintaining the weight and shape of a resin for a certain period of time in hot water at a temperature higher than 135 ° C. in a method with less process contamination.

The present inventors diligently studied a resin composition that rapidly decomposes after maintaining the weight and shape of the resin for a certain period in hot water at a temperature higher than 135 ° C.
As a result, if the acid group concentration can be kept low using a resin with autocatalytic action, hydrolysis and the decrease in molecular weight during that time will be moderated, so the weight and shape will be maintained, and the acid group concentration will be kept low. It was found that the decomposition of the resin was promoted when it became impossible (see FIG. 3).
As a result of further investigation, by using a carbodiimide compound having a water resistance at 120 ° C. of 95% or more and a reactivity with an acidic group at 190 ° C. of 50% or more for sealing of acidic groups, the temperature is higher than 135 ° C. It was found that the acidic group concentration can be efficiently kept low in hot water and the timing of resin decomposition can be controlled by the amount of addition.
However, the carbodiimide compound satisfying the above water resistance and reactivity with acidic groups is a compound having an isocyanate group in association with a reaction in which the agent itself leaks during processing, and the carbodiimide compound is bonded to the terminal of the polymer compound. There is a problem of being liberated.
Thus, as a result of intensive studies, the present inventors have reached the present invention by arranging a resin composition that does not substantially contain a hydrolysis regulator in the sheath of the core-sheath composite fiber. By disposing a layer substantially not containing a hydrolysis regulator on the surface of the fiber, the process contamination by the carbodiimide compound and the compound having an isocyanate group is reduced in the spinning process, and the heating process and hot water after spinning are performed. It has been found that a desired hydrolyzability can be obtained in high-temperature hot water by diffusing the carbodiimide compound to the fiber surface by the heat inside.
That is, the object of the present invention can be achieved by the following.
1. A method for producing a core-sheath type composite fiber composed of a core part and a sheath part,
A resin composition (C component) containing a resin (A component) having an autocatalytic action and a hydrolysis regulator (B component) is disposed in the core part, and a resin having an autocatalytic action is provided in the sheath part. A resin composition (D component) that is substantially free of hydrolysis modifier (B component) is arranged in (A ′ component), and the hydrolysis regulator (B component) in the resin composition (C component) is all A method for producing a core-sheath composite fiber, characterized in that the amount is 1 to 40 parts by weight based on the weight.
2. The manufacturing method of said 1 satisfy | filling following formula (I).

(However, in the formula, Qc: discharge amount of the core portion, Qs: discharge amount of the sheath portion, D: diameter of the discharge port)
3. 3. The production method according to 1 or 2 above, wherein the resin (component A) having an autocatalytic action is a polyester.
4). 4. The production method according to any one of 1 to 3 above, wherein the resin (component A) having autocatalytic action has a main chain mainly composed of water-soluble monomer units.
5. 5. The production method according to 4 above, wherein the resin (component A) having an autocatalytic action has a main chain mainly composed of lactic acid units represented by the following formula (1).

6). 6. The production method according to 5 above, wherein the resin (component A) having an autocatalytic action includes a stereocomplex phase formed by poly L-lactic acid and poly D-lactic acid.
7). 7. The production method according to any one of 1 to 6 above, wherein the hydrolysis regulator (component B) has a carbodiimide group.
8). 8. The production method according to 7 above, wherein the hydrolysis regulator (component B) is a carbodiimide compound represented by the following formula (2).

(Wherein R ₁ to R ₄ are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, X and Y may each independently represent a hydrogen atom, an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or these (It is a combination and may contain a hetero atom. Each aromatic ring may be bonded by a substituent to form a cyclic structure.)
9. 9. The production method according to 8 above, wherein the hydrolysis regulator (component B) is bis (2,6-diisopropylphenyl) carbodiimide.
10. 9. The production method according to 8 above, wherein the hydrolysis regulator (component B) is a carbodiimide compound comprising a repeating unit represented by the following formula (3).

(Wherein R ₅ to R ₇ are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, (It may contain atoms.)
11. 11. The production method according to any one of 1 to 10 above, wherein the resin having the autocatalytic action contained in the core part (component A) and the resin having the autocatalytic action contained in the sheath part (A ′ component) are the same resin. .
12 12. The production method according to any one of 1 to 11 above, comprising a step of performing a heat treatment at 60 ° C. or higher after spinning.
13. 13. A core-sheath type composite fiber produced by the method according to any one of 1 to 12 above.
14 14. The fiber according to 13 above, which satisfies the following formula (α) when microscopic IR measurement is performed on two orthogonal straight lines passing through the center of the fiber cross section.

(However, in the formula, PIs: average value of IR peak intensity ratio obtained from carbodiimide group / carbonyl group at four points on the fiber surface, PIc: highest IR peak intensity ratio obtained from carbodiimide group / carbonyl group at fiber center)
15. When microscopic IR measurement is performed on two orthogonal straight lines passing through the center on the cross section of the fiber, the average value of the four points b existing on the circumference having ra as _a radius satisfying the following formula (β) is expressed by the following formula: 15. The fiber according to the above 14, satisfying (γ).

(Wherein, r: distance from the center of the fiber cross-section on each of the microscopic IR measurement linear to the fiber surface, r _a: is on each having a microscopic IR measurement linear, fiber cross-section on 0 <r _a <r) to a point a existing between the center of the fiber and the fiber surface

(However, in the formula, PIb: IR peak intensity ratio obtained from carbodiimide group / carbonyl group at a certain point b existing between each point a and the fiber surface on each straight line obtained by microscopic IR measurement)
16. A core-sheath type composite fiber composed of a core part and a sheath part,
(I) The core is composed of a resin composition (C component) containing a resin (A component) having autocatalytic action and a hydrolysis regulator (B component), and the content of the hydrolysis regulator (B component) Is 1 to 40 parts by weight based on the total weight,
(Ii) The sheath part contains a hydrolysis regulator (B component) at a lower concentration than the C component in the resin (A ′ component) having autocatalytic action, or substantially contains the hydrolysis regulator (B component). A resin composition not contained (component D),
(Iii) The core-sheath type composite fiber according to the above 13, wherein the acidic end group amount of the composite fiber is 5 eq / ton or less.
17. 17. The core-sheath type composite fiber according to 16, wherein the resin (A component) having autocatalytic activity of the core part and the resin (A ′ component) having autocatalytic action of the sheath part are the same resin.

ADVANTAGE OF THE INVENTION According to this invention, the fiber which decomposes | disassembles after hold | maintaining the weight and shape of resin for a fixed period in hot water higher than 135 degreeC can be provided with little process contamination. By using a carbodiimide compound having a water resistance at 120 ° C. of 95% or more and a reactivity with an acidic group at 190 ° C. of 50% or more for the sealing of acidic groups, it is possible to perform steady decomposition suppression, The timing of resin decomposition in hot hot water can be controlled by the amount added. With these carbodiimide compounds, the compound having an isocyanate group is liberated along with the reaction of bonding to the terminal of the polymer compound, and the carbodiimide compound itself leaks out and contaminates the process, but the production method of the present invention Therefore, the fiber of the present invention can be provided with less process contamination.
Further, the fiber obtained by the production method of the present invention exhibits a desired performance in an oil field excavation technique and can be suitably used.

FIG. 1 is an image diagram that quickly decomposes after maintaining the weight and shape of a resin for a certain period when the resin is used in hot water at a temperature higher than 135 ° C., and shows the behavior achieved in the fiber of the present invention. is there.
FIG. 2 is an image diagram in which decomposition rapidly proceeds from the initial stage when a resin is used in hot water at a temperature higher than 135 ° C., and is a behavior in a general aliphatic polyester.
FIG. 3 shows the molecular weight (m) and the amount of acidic groups (m) necessary to achieve the behavior of the resin weight (w) change as shown in FIG. 1 when the resin is used in hot water at a temperature higher than 135 ° C. FIG. 6 is an image diagram showing a change in g), which is a behavior achieved in the fiber of the present invention.

Hereinafter, the present invention will be described in detail.
<Resin having autocatalytic action (component A)>
In the present invention, the resin (component A) having an autocatalytic action is a resin in which an acidic group generated by decomposition has an autocatalytic action.
The component A preferably contains a water-soluble monomer as a main component. For example, as described in US Pat. No. 7,275,596, for example, in the case of an aromatic polyester, a monomer generated by decomposition may react with other components in this application and precipitate in water. Because.
Here, water solubility means that the solubility in water at 25 ° C. is 0.1 g / L or more. The solubility of the water-soluble monomer in water is preferably 1 g / L or more, more preferably 3 g / L or more, from the viewpoint that the resin composition to be used does not remain in water after decomposition. More preferably, it is the above.
Moreover, a main component is 90 mol% or more of a structural component. The proportion of the main component is preferably 95 to 100 mol%, more preferably 98 to 100 mol%.
Examples of the component A include at least one selected from the group consisting of polyester, polyamide, polyamideimide, polyimide, polyurethane, and polyesteramide. Preferably polyester is illustrated.
Examples of the polyester include a polymer or copolymer obtained by polycondensation of one or more selected from dicarboxylic acid or an ester-forming derivative thereof and diol or an ester-forming derivative thereof, hydroxycarboxylic acid or an ester-forming derivative thereof, or a lactone. Is exemplified. Preferred examples include polyesters made of hydroxycarboxylic acid or ester-forming derivatives thereof. More preferably, an aliphatic polyester composed of hydroxycarboxylic acid or an ester-forming derivative thereof is exemplified.
Such a thermoplastic polyester may contain a cross-linked structure treated with a radical generation source such as an energy active ray or an oxidizing agent for moldability and the like.
Dicarboxylic acid or ester-forming derivatives include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, bis (p-carboxyphenyl) methane, anthracene dicarboxylic acid, 4, Aromatic dicarboxylic acids such as 4′-diphenyl ether dicarboxylic acid, 5-tetrabutylphosphonium isophthalic acid and 5-sodium sulfoisophthalic acid can be mentioned. Moreover, aliphatic dicarboxylic acids, such as oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, and dimer acid, are mentioned. Moreover, alicyclic dicarboxylic acids, such as 1, 3- cyclohexane dicarboxylic acid and 1, 4- cyclohexane dicarboxylic acid, are mentioned. Moreover, these ester-forming derivatives are mentioned.
Examples of the diol or ester-forming derivative thereof include aliphatic glycols having 2 to 20 carbon atoms, that is, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5 -Pentanediol, 1,6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, dimer diol and the like.
Further, long-chain glycols having a molecular weight of 200 to 100,000, that is, polyethylene glycol, poly 1,3-propylene glycol, poly 1,2-propylene glycol, polytetramethylene glycol and the like can be mentioned. In addition, aromatic dioxy compounds, that is, 4,4′-dihydroxybiphenyl, hydroquinone, tert-butylhydroquinone, bisphenol A, bisphenol S, bisphenol F and the like can be mentioned. Moreover, these ester-forming derivatives are mentioned.
Examples of the hydroxycarboxylic acid include glycolic acid, lactic acid, hydroxypropioic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxybenzoic acid, p-hydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, and these Examples thereof include ester-forming derivatives. Examples of the lactone include caprolactone, valerolactone, propiolactone, undecalactone, and 1,5-oxepan-2-one.
Examples of the aliphatic polyester include a polymer mainly composed of an aliphatic hydroxycarboxylic acid, a polymer obtained by polycondensation of an aliphatic polyvalent carboxylic acid or an ester-forming derivative thereof and an aliphatic polyhydric alcohol as main components, and those polymers. Copolymers are exemplified.
Examples of the polymer having an aliphatic hydroxycarboxylic acid as a main constituent component include polycondensates such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, hydroxyvaleric acid, and hydroxycaproic acid, and copolymers. Among these, polyglycolic acid, polylactic acid, poly-3-hydroxycarboxylic butyric acid, poly-4-polyhydroxybutyric acid, poly-3-hydroxyhexanoic acid or polycaprolactone, and copolymers thereof can be mentioned. Particularly, poly L-lactic acid, poly D-lactic acid, stereocomplex polylactic acid, and racemic polylactic acid can be mentioned.
Moreover, the polymer which has aliphatic polyhydric carboxylic acid and aliphatic polyhydric alcohol as the main structural components is mentioned. As polyvalent carboxylic acids, oxalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, malonic acid, glutaric acid, dimer acid and other aliphatic dicarboxylic acids, 1,3-cyclohexanedicarboxylic acid, 1, Examples include alicyclic dicarboxylic acid units such as 4-cyclohexanedicarboxylic acid and ester derivatives thereof. Further, as the diol component, an aliphatic glycol having 2 to 20 carbon atoms, that is, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,6 -Hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, dimer diol and the like. Further, long chain glycols having a molecular weight of 200 to 100,000, that is, polyethylene glycol, poly 1,3-propylene glycol, poly 1,2-propylene glycol, and polytetramethylene glycol can be mentioned. Specific examples include polyethylene adipate, polyethylene succinate, polybutylene adipate or polybutylene succinate, and copolymers thereof.
Polyester can be produced by a known method (for example, a saturated polyester resin handbook (written by Kazuo Yuki, published by Nikkan Kogyo Shimbun, published December 22, 1989)).
Furthermore, examples of the polyester include an unsaturated polyester resin obtained by copolymerizing an unsaturated polyvalent carboxylic acid or an ester-forming derivative thereof in addition to the polyester, and a polyester elastomer containing a low melting point polymer segment.
Examples of the unsaturated polycarboxylic acid include maleic anhydride, tetrahydromaleic anhydride, fumaric acid, endomethylenetetrahydromaleic anhydride and the like. In order to control the curing characteristics, various monomers are added to the unsaturated polyester, and it is cured and molded by a curing treatment with an active energy beam such as thermal curing, radical curing, light, or electron beam.
Further, in the present invention, the polyester may be a polyester elastomer obtained by copolymerizing a soft component. The polyester elastomer is a block copolymer composed of a high melting point polyester segment and a low melting point polymer segment having a molecular weight of 400 to 6,000 as described in known literatures such as JP-A-11-92636. When the polymer is formed only from the high melting point polyester segment, the melting point is 150 ° C. or more, which can be suitably used.
The polyester is preferably a polyester comprising a hydroxycarboxylic acid or an ester-forming derivative thereof. Further, an aliphatic polyester composed of hydroxycarboxylic acid or an ester-forming derivative thereof is more preferable. Furthermore, it is particularly preferable that the aliphatic polyester is poly L-lactic acid, poly D-lactic acid, and stereocomplex polylactic acid.
Here, polylactic acid consists of lactic acid units whose main chain is represented by the following formula (1). In the present specification, “mainly” is preferably a ratio of 90 to 100 mol%, more preferably 95 to 100 mol%, and still more preferably 98 to 100 mol%.

The lactic acid unit represented by the formula (1) includes an L-lactic acid unit and a D-lactic acid unit, which are optical isomers. The main chain of the polylactic acid is preferably mainly an L-lactic acid unit, a D-lactic acid unit or a combination thereof.
The polylactic acid is preferably poly-D-lactic acid whose main chain is mainly composed of D-lactic acid units, and poly-L-lactic acid whose main chain is mainly composed of L-lactic acid units. The proportion of other units constituting the main chain is preferably in the range of 0 to 10 mol%, more preferably 0 to 5 mol%, and still more preferably 0 to 2 mol%.
Examples of other units constituting the main chain include units derived from dicarboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, lactones and the like.
Examples of the dicarboxylic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, terephthalic acid, and isophthalic acid. Examples of the polyhydric alcohol include aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, octanediol, glycerin, sorbitan, neopentyl glycol, diethylene glycol, triethylene glycol, polyethylene glycol, and polypropylene glycol. Or aromatic polyhydric alcohol etc., such as what added ethylene oxide to bisphenol, etc. are mentioned. Examples of the hydroxycarboxylic acid include glycolic acid and hydroxybutyric acid. Examples of the lactone include glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, and the like.
The weight average molecular weight of the polylactic acid is preferably 50,000 to 500,000, more preferably 80,000 to 350,000, and even more preferably 100,000 to 250,000 in order to achieve both hot water durability, mechanical properties and moldability of the fiber. It is a range. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.
When the resin having a self-catalytic action (component A) is polylactic acid (poly D-lactic acid or poly L-lactic acid) and is a homophase polylactic acid, it is 150 to 190 ° C. as measured by a differential scanning calorimeter (DSC). It preferably has a crystal melting peak (Tmh) between them and a heat of crystal melting (ΔHmsc) of 10 J / g or more. Heat resistance can be improved by satisfying the range of the crystal melting point and the crystal melting heat.
When the resin (component A) having an autocatalytic action is polylactic acid, the optical purity of poly L-lactic acid or poly D-lactic acid constituting the polylactic acid is preferably 98% or more, more preferably 98. 0.5% or more, more preferably 99% or more, and most preferably 99.5% or more. When the optical purity is low, a high melting point homophase polylactic acid may not be obtained.
The higher the optical purity, the higher the melting point of the stereocomplex crystal phase obtained by DSC, preferably 165 ° C. or higher, more preferably 170 ° C. or higher, more preferably 173 ° C. or higher, most preferably 175 ° C. or higher. .
The main chain of polylactic acid is preferably stereocomplex polylactic acid including a stereocomplex phase formed by poly L-lactic acid units and poly D-lactic acid units.
Stereocomplex polylactic acid preferably exhibits a crystal melting peak of 190 ° C. or higher by differential scanning calorimetry (DSC) measurement.
The stereocomplex polylactic acid preferably has a stereocomplexation degree (S) defined by the following formula of 30 to 100%.
S = [ΔHms / (ΔHmh + ΔHms)] × 100
(However, ΔHms represents the crystal melting enthalpy of stereocomplex phase polylactic acid, and ΔHmh represents the melting enthalpy of polylactic acid homophase crystal.)
The crystallinity of stereocomplex polylactic acid, particularly the crystallinity by XRD measurement, is in the range of 3 to 60%, more preferably 5 to 60%, still more preferably 7 to 60%, and particularly preferably 10 to 60%. .
The crystal melting point of stereocomplex polylactic acid is preferably in the range of 190 to 250 ° C., more preferably 200 to 230 ° C. The crystal melting enthalpy by DSC measurement of stereocomplex polylactic acid is preferably 20 J / g or more, more preferably 20 to 80 J / g, still more preferably 30 to 80 J / g. When the crystalline melting point of stereocomplex polylactic acid is less than 190 ° C., the heat resistance is deteriorated. Moreover, when it exceeds 250 degreeC, it will be necessary to shape | mold at the high temperature of 250 degreeC or more, and it may become difficult to suppress thermal decomposition of resin. Therefore, it is preferable that the resin composition of the present invention exhibits a crystal melting peak of 190 ° C. or higher as measured by a differential scanning calorimeter (DSC).
In addition, the isotactic number average chain length of polylactic acid (L _i ) Is preferably 30 to 200, more preferably 35 to 150, still more preferably 40 to 120, and particularly preferably 45 to 100. When it is smaller than 30, the melting point of the stereocomplex crystal phase becomes low, and when it is larger than 200, it becomes difficult to form the stereocomplex crystal phase.
Isotactic number average chain length (L _i ) Shows the peak of the quadruple structure of CH carbon of polylactic acid in Makromol. Chem. , 191, 287 (1990), and according to Polymer, 33, 2817 (1992), the area ratio (I _iii , I _isi , I _sii , I _iis , I _sis , I _ssi , I _iss , I _sss ) Is a value defined by the following formula. i represents isotactic (LL, DD), and s represents syndiotactic (LD, DL) linkage.
L _i = (3I _iii + 2I _isi + 2I _sii + 2I _iis + I _sis + I _ssi + I _iss ) / (I _isi + I _iis + I _sii + 2I _sis + 2I _ssi + 2I _iss + 3I _sss +1
In the stereocomplex polylactic acid, the weight ratio of poly D-lactic acid to poly L-lactic acid is preferably 90/10 to 10/90. More preferably, it is in the range of 80/20 to 20/80, more preferably 30/70 to 70/30, particularly preferably 40/60 to 60/40, and theoretically preferably as close to 1/1 as possible. .
The weight average molecular weight of the stereocomplex polylactic acid is preferably in the range of 50,000 to 500,000, more preferably 80,000 to 350,000, and still more preferably 100,000 to 250,000. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.
Poly L-lactic acid and poly D-lactic acid can be produced by a conventionally known method. For example, it can be produced by ring-opening polymerization of L-lactide or D-lactide in the presence of a metal-containing catalyst. In addition, low molecular weight polylactic acid containing a metal-containing catalyst is crystallized as desired or without crystallization, under reduced pressure or from normal pressure, in the presence of an inert gas stream, or absent It can also be produced by solid phase polymerization. Furthermore, it can be produced by a direct polymerization method in which lactic acid is subjected to dehydration condensation in the presence or absence of an organic solvent.
The polymerization reaction can be carried out in a conventionally known reaction vessel. For example, in a ring-opening polymerization or direct polymerization method, a vertical reactor or a horizontal reactor equipped with a stirring blade for high viscosity, such as a helical ribbon blade, is used alone, or Can be used in parallel. Moreover, any of a batch type, a continuous type, a semibatch type may be sufficient, and these may be combined.
Alcohol may be used as a polymerization initiator. Such alcohol is preferably non-volatile without inhibiting the polymerization of polylactic acid, such as decanol, dodecanol, tetradecanol, hexadecanol, octadecanol, ethylene glycol, trimethylolpropane, pentaerythritol, etc. Can be suitably used. It can be said that the polylactic acid prepolymer used in the solid-phase polymerization method is preferably crystallized in advance from the viewpoint of preventing resin pellet fusion. The prepolymer is in a solid state in a fixed vertical or horizontal reaction vessel, or in a reaction vessel (such as a rotary kiln) in which the vessel itself rotates, such as a tumbler or kiln, in the temperature range from the glass transition temperature of the prepolymer to less than the melting point. Polymerized.
Metal-containing catalysts include alkali metals, alkaline earth metals, rare earths, transition metals, fatty acid salts such as aluminum, germanium, tin, antimony, titanium, carbonates, sulfates, phosphates, oxides, hydroxides , Halides, alcoholates and the like. Among them, fatty acid salts, carbonates, sulfates, phosphates, oxides, hydroxides containing at least one metal selected from tin, aluminum, zinc, calcium, titanium, germanium, manganese, magnesium and rare earth elements Products, halides, and alcoholates are preferred.
Tin compounds due to low catalytic activity and side reactions, specifically stannous chloride, stannous bromide, stannous iodide, stannous sulfate, stannic oxide, tin myristate, tin octylate Tin-containing compounds such as tin stearate and tetraphenyltin are exemplified as preferred catalysts. Among these, tin (II) compounds, specifically, diethoxytin, dinonyloxytin, tin (II) myristate, tin (II) octylate, tin (II) stearate, tin (II) chloride and the like are suitable. Illustrated.
The amount of catalyst used is 0.42 x 10 per kg of lactide. ^-4 ~ 100 × 10 ^-4 (Mole) and further considering the reactivity, color tone and stability of the resulting polylactides, 1.68 × 10 ^-4 ~ 42.1 × 10 ^-4 (Mole), particularly preferably 2.53 × 10 ^-4 ~ 16.8 × 10 ^-4 (Mol) used.
The metal-containing catalyst used for the polymerization of polylactic acid is preferably deactivated with a conventionally known deactivator prior to using polylactic acid. Examples of such a deactivator include an organic ligand having a group of chelate ligands having an imino group and capable of coordinating with a polymerized metal catalyst.
Also, dihydridooxoline (I) acid, dihydridotetraoxodiphosphorus (II, II) acid, hydridotrioxoline (III) acid, dihydridopentaoxodiphosphoric acid (III), hydridopentaoxodi (II, IV) Acid, dodecaoxohexaphosphoric acid (III), hydridooctaoxotriphosphoric acid (III, IV, IV) acid, octaoxotriphosphoric acid (IV, III, IV) acid, hydridohexaoxodiphosphoric acid (III, V) acid, hexaoxodiacid Examples thereof include low oxidation number phosphoric acids having an acid number of 5 or less, such as phosphorus (IV) acid, decaoxotetraphosphoric (IV) acid, hendecaoxotetraphosphoric (IV) acid, and eneoxooxophosphorus (V, IV, IV) acid.
Also xH ₂ O • yP ₂ O ₅ And orthophosphoric acid of x / y = 3. Moreover, polyphosphoric acid which is 2> x / y> 1, and is called diphosphoric acid, triphosphoric acid, tetraphosphoric acid, pentaphosphoric acid or the like based on the degree of condensation, and a mixture thereof are exemplified. Moreover, the metaphosphoric acid represented by x / y = 1, especially trimetaphosphoric acid and tetrametaphosphoric acid are mentioned. Further, ultraphosphoric acid represented by 1> x / y> 0 and having a network structure in which a part of the phosphorus pentoxide structure is partially removed (these may be collectively referred to as a metaphosphoric acid compound) may be mentioned. . Moreover, the acid salt of these acids is mentioned. Moreover, the monovalent | monohydric and polyhydric alcohol of these acids, the partial ester of polyalkylene glycol, and complete ester are mentioned. Examples thereof include phosphono-substituted lower aliphatic carboxylic acid derivatives of these acids.
From the catalyst deactivation ability, the formula xH ₂ O • yP ₂ O ₅ An orthophosphoric acid represented by x / y = 3 is preferred. Moreover, 2> x / y> 1, and polyphosphoric acid referred to as diphosphoric acid, triphosphoric acid, tetraphosphoric acid, pentaphosphoric acid and the like, and a mixture thereof are preferable from the degree of condensation. Further, metaphosphoric acid represented by x / y = 1, particularly trimetaphosphoric acid and tetrametaphosphoric acid are preferable. Ultraphosphoric acid represented by 1> x / y> 0 and having a network structure in which a part of the phosphorus pentoxide structure is left (these may be collectively referred to as a metaphosphoric acid compound) is preferable. Moreover, the acidic salt of these acids is preferable. Further, monovalent or polyhydric alcohols of these acids or partial esters of polyalkylene glycols are preferred.
The metaphosphoric acid compound used in the present invention is a cyclic metaphosphoric acid in which about 3 to 200 phosphoric acid units are condensed, an ultra-regional metaphosphoric acid having a three-dimensional network structure, or an alkali metal salt or an alkaline earth metal salt thereof. Onium salts). Among them, cyclic sodium metaphosphate, ultra-region sodium metaphosphate, phosphono-substituted lower aliphatic carboxylic acid derivative dihexylphosphonoethyl acetate (hereinafter sometimes abbreviated as DHPA) and the like are preferably used.
The polylactic acid preferably has a lactide content of 5,000 ppm or less. The lactide contained in the polylactic acid deteriorates the resin and deteriorates the color tone at the time of melt processing, and in some cases, it may be disabled as a product.
Poly L-lactic acid and / or poly D-lactic acid immediately after the melt ring-opening polymerization usually contains 1 to 5% by weight of lactide, but poly L-lactic acid and / or poly D-lactic acid is At any stage up to lactic acid molding, a conventionally known lactide weight loss method, that is, vacuum devolatilization with a single-screw or multi-screw extruder, or high vacuum treatment in a polymerization apparatus is carried out alone or in combination. In addition, lactide can be reduced to a suitable range.
The smaller the lactide content, the better the melt stability and heat-and-moisture resistance of the resin, but there is also the advantage of lowering the resin melt viscosity, making it reasonable and economical to meet the desired purpose. is there. That is, it is reasonable to set it to 1,000 ppm or less, at which practical melt stability is achieved. More preferably, a range of 700 ppm or less, more preferably 500 ppm or less, particularly preferably 100 ppm or less is selected. The polylactic acid component has a lactide content within such a range, thereby improving the stability of the resin during melt molding of the molded product of the present invention, and the advantage that the molded product can be efficiently manufactured, and the moisture resistant heat stability of the molded product. , Low gas can be improved.
Further, when the resin (component A) having an autocatalytic action is stereocomplex polylactic acid, the optical purity of poly L-lactic acid and poly D-lactic acid constituting polylactic acid is preferably 98% or more, more preferably It is 98.5% or more, more preferably 99% or more, and most preferably 99.5% or more. When the optical purity is low, the isotactic number average chain length does not become long, and a high-melting stereocomplex crystal phase may not be obtained.
The higher the optical purity, the higher the melting point of the stereocomplex crystal phase obtained by DSC, preferably 200 ° C or higher, more preferably 205 ° C or higher, more preferably 210 ° C or higher, most preferably 215 ° C or higher. .
Stereocomplex polylactic acid is prepared by bringing poly L-lactic acid and poly D-lactic acid into contact in a weight ratio of 10/90 to 90/10, preferably by melt contact, and more preferably melt kneading. Can be obtained. The contact temperature is preferably in the range of 210 to 300 ° C., more preferably 220 to 290 ° C., and further preferably 225 to 280 ° C. from the viewpoints of stability of polylactic acid when melted, thermal decomposition, and improvement of stereocomplex crystallinity. It is.
The method of melt kneading is not particularly limited, but a conventionally known batch type or continuous type melt mixing apparatus is preferably used. For example, a melt-stirred tank, a single-screw or twin-screw extruder, a kneader, a non-shaft vertical stirring tank, “Vibolac (registered trademark)” manufactured by Sumitomo Heavy Industries, Ltd., N-SCR, manufactured by Mitsubishi Heavy Industries, Ltd. ( Glasses blades, lattice blades or Kenix type stirrers made by Hitachi, Ltd., or Sulzer type SMLX type static mixer equipped pipe type polymerization equipment can be used, but self-cleaning type in terms of productivity, quality of polylactic acid, especially color tone. A non-axial vertical stirring tank, an N-SCR, a twin-screw extruder, or the like that is a polymerization apparatus is preferably used.
In the polylactic acid used in the present invention, a method of blending a specific additive in order to stably and highly promote the formation of stereocomplex polylactic acid crystals is preferably applied without departing from the gist of the present invention. The additive is not particularly limited as long as it has a transesterification catalytic ability. Among them, organic acid metal salts are preferably used, and examples thereof include known phosphoric acid metal salts, carboxylic acid metal salts, and sulfonic acid metal salts.
<Hydrolysis regulator (component B)>
In the present invention, the hydrolysis regulator (component B) is an agent that seals the terminal groups of the resin (component A) and acidic groups generated by the decomposition. That is, the agent has an effect of suppressing the autocatalytic action of the resin (component A) and delaying the hydrolysis.
Examples of the acidic group include at least one selected from the group consisting of a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphonic acid group, and a phosphinic acid group. In the present invention, a carboxyl group is particularly exemplified.
Since the use conditions are hot water higher than 135 ° C., the B component preferably has a water resistance at 120 ° C. of 95% or more and a reactivity with acidic groups at 190 ° C. of 50% or more.
Here, the water resistance at 120 ° C. means, for example, 1) 2 g of water is added to a system in which 1 g of B component is dissolved in 50 ml of dimethyl sulfoxide, and dissolved when stirred at 120 ° C. for 5 hours while refluxing. Approximate amount of the agent that remains unchanged after 5 hours of treatment calculated from the analysis of the part that is present, or 2) If it does not dissolve in dimethyl sulfoxide, the B component can be dissolved and hydrophilic It is a value represented by the following formula (iv) using an approximate amount obtained by performing the same treatment as in 1) above using a certain solvent.
In 2), when the boiling point of the solvent to be used was less than 120 ° C., dimethyl sulfoxide was mixed with the solvent in a range where at least a part of the component B was dissolved, and 50 ml of the mixed solvent was used. The mixing ratio is usually selected from the range of (1: 2) to (2: 1), but is not particularly limited as long as the above conditions are satisfied. The solvent used in 2) is usually soluble if selected from tetrahydrofuran, N, N-dimethylformamide, and ethyl acetate.
Water resistance (%) = [Amount after 5 hours treatment / initial amount] × 100 (iv)
In addition, the water resistance may be expressed by an equivalent evaluation.
When the water resistance of an unstable agent is evaluated, a part of the agent is denatured by hydrolysis, and the acidic group sealing ability is lowered. When such an agent is used in hot hot water, it is deactivated by water, so that the ability to seal the target acidic group is significantly reduced. From the above, the water resistance at 120 ° C. is more preferably 97% or more, further preferably 99% or more, and particularly preferably 99.9% or more. When it is 99.9% or more, that is, stable in high-temperature hot water, the reaction with acidic groups can be carried out selectively and efficiently.
Moreover, the reactivity with an acidic group at 190 ° C. means, for example, that a group that reacts with a carboxyl group of a hydrolysis modifier is 1. It is obtained by adding an amount of an agent equivalent to 5 times equivalent and melt-kneading for 1 minute at a resin temperature of 190 ° C. and a rotation speed of 30 rpm in a nitrogen atmosphere using a lab plast mill (manufactured by Toyo Seiki Seisakusho). With respect to the resin composition, the carboxyl group concentration was measured, and the value given by the following formula (v).
Reactivity (%) = [(carboxyl group concentration of polylactic acid for evaluation−carboxyl group concentration of resin composition) / carboxyl group concentration of polylactic acid for evaluation] × 100 (v)
The evaluation polylactic acid preferably has a MW of 120,000 to 200,000 and a carboxyl group concentration of 10 to 30 equivalents / ton. As such polylactic acid, for example, polylactic acid “NW3001D” (MW is 150,000, carboxyl group concentration is 22.1 equivalent / ton) manufactured by Nature Works can be preferably used. Add the amount of the agent that makes the group that reacts with the carboxyl group of the adjusting agent 33.15 equivalents / ton, and use Labo Plast Mill (manufactured by Toyo Seiki Seisakusho Co., Ltd.) under a nitrogen atmosphere under a resin temperature of 190 ° C., The reactivity value can be obtained by measuring the carboxyl group concentration of the resin composition obtained by melt-kneading for 1 minute at a rotation speed of 30 rpm.
In addition to this, the reactivity with an acidic group may be given by an equivalent evaluation.
When the reactivity of a stable agent is evaluated, the carboxyl group concentration of the resin composition hardly changes even when kneaded under the above conditions. Such an agent, when used in high-temperature hot water, hardly exhibits the ability to seal the target acidic group, and therefore cannot suppress the decomposition of the resin (component A).
From the above, the reactivity with acidic groups at 190 ° C. is more preferably 60% or more, further preferably 70% or more, and particularly preferably 80% or more. When the reactivity with acidic groups in high-temperature hot water is 80% or more, the reaction with acidic groups can be carried out efficiently.
It is important that the hydrolysis regulator (component B) has a water resistance at 120 ° C. of 95% or more and a reactivity with acidic groups at 190 ° C. of 50% or more. That is, a very stable agent has a high water resistance, but a low reactivity with acidic groups. In that case, the ability to seal the target acidic groups in hot hot water is almost manifested. do not do. In addition, a very unstable agent has a high reactivity with an acidic group, but has a low water resistance. In that case, it is deactivated by water in high-temperature hot water. The ability to seal is significantly reduced.
From the above, the hydrolysis regulator having high water resistance and high reactivity with acidic groups is preferably used in the present invention.
Examples of the component B include addition reaction type compounds such as carbodiimide compounds, isocyanate compounds, epoxy compounds, oxazoline compounds, oxazine compounds, and aziridine compounds. Two or more of these compounds can be used in combination. From the viewpoint of water resistance and reactivity with acidic groups, a carbodiimide compound is preferably exemplified.
Examples of the carbodiimide compound include those having the basic structures of the following general formulas (4) and (5).

(Wherein R ₈ , R ₉ Are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, and may contain a hetero atom. R ₈ And R ₉ May be bonded to form a cyclic structure, or two or more cyclic structures may be formed by a spiro structure or the like)

(Wherein R ₁₀ Is an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, and may contain a hetero atom. n is an integer of 2 to 1000. )
From the viewpoints of stability and ease of use, an aromatic carbodiimide compound is more preferable. For example, aromatic carbodiimide compounds such as the following formulas (2) and (3) are exemplified.

(Wherein R ₁ ~ R ₄ Are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, and may contain a hetero atom. X and Y are each independently a hydrogen atom, an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof. May be included. Each aromatic ring may be bonded by a substituent to form a cyclic structure, or two or more cyclic structures may be formed by a spiro structure or the like)

(Wherein R ₅ ~ R ₇ Are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, and may contain a hetero atom. n is an integer of 2 to 1000. )
Specific examples of such aromatic carbodiimide compounds include polysynthesized by decarboxylation condensation reaction of bis (2,6-diisopropylphenyl) carbodiimide and 1,3,5-triisopropylbenzene-2,4-diisocyanate. Examples thereof include carbodiimide and a combination of the two.
<Resin composition>
The core-sheath-type conjugate fiber of the present invention is formed from at least two types of resin compositions: a resin composition (C component) that forms a core part and a resin composition (D component) that forms a sheath part.
A core part consists of a resin composition (C component) containing resin (A component) which has an autocatalytic action, and a hydrolysis regulator (B component).
The resin composition (component C) retains its shape for a certain period in hot water at 135 ° C. or higher, and then the effect of sealing the acidic group of the hydrolysis modifier (component B) disappears. The autocatalytic action promotes the decomposition of the resin, and accordingly, the concentration of acidic groups increases exponentially and further promotes the decomposition.
It is suitable when the resin composition of the present invention is used in an oil field excavation technique or the like that the phenomenon occurs as soon as possible after maintaining the weight and shape of the resin for a certain period. In addition, when the main chain of the resin is mainly composed of water-soluble monomer units, the decomposition product is dissolved in water.
Therefore, it is necessary that the weight of the non-water-soluble content of the resin composition is less than 30% after 100 hours in hot water at an arbitrary temperature of 135 ° C. or higher. The timing at which the decomposition rate changes abruptly can be controlled by the amount of hydrolysis modifier added. In consideration of the volume ratio between the core and the sheath, the resin composition (C component) as a whole is 100 parts by weight, the resin (A component) is 60 to 99 parts by weight, and the hydrolysis regulator (B component) is 1 part. Contains ~ 40 parts by weight. If the content of the hydrolysis regulator (component B) is less than 1 part by weight, the hydrolysis regulator may not spread over the entire fiber, and a sufficient acidic group sealing effect may not be exhibited. On the other hand, when the amount is more than 40 parts by weight, the moldability may be deteriorated, process contamination may occur. From this viewpoint, the content of the hydrolysis regulator (component B) is preferably 1 to 40 parts by weight, more preferably 2 to 30 parts by weight, still more preferably 3 to 20 parts by weight, and most preferably 5 to 15 parts by weight. preferable.
A sheath part is a resin composition (D component) which does not contain a hydrolysis regulator (B component) substantially in resin (A 'component) which has an autocatalytic action. The resin composition (component D) is disposed in the sheath part, and it is necessary to reduce leakage of the isocyanate compound generated in the core part and the hydrolysis regulator itself to the outside of the fiber.
Moreover, it is preferable to use the same resin as the resin (A component) having an autocatalytic action used for the resin composition (C component) as the resin having an autocatalytic action (A ′ component). When the same material is used, the hydrolysis regulator (component B) in the resin composition (component C) is the fiber after the spinning step and heat in hot water. It is because it diffuses more uniformly in the inside.
In the core-sheath type composite fiber of the present invention, the content of the hydrolysis adjusting agent (B component) of the resin composition (C component) of the core part is the hydrolysis adjusting agent (D component) of the resin composition (D component) of the sheath part ( More than the content of B component).
Content of the hydrolysis regulator (B component) of the resin composition (C component) of a core part and the resin composition (D component) of a sheath part can be analyzed by the following method. The core-sheath type composite fiber is cut into a cross section perpendicular to the fiber length direction with a microtome equipped with a sharp blade, and the cross-sectional microscopic IR mapping measurement is performed, and the IR absorption peak area peculiar to the hydrolysis regulator (component B) In addition, IR absorption peak areas peculiar to resins having autocatalytic action (component A and component A ′) are two-dimensionally mapped. For microscopic IR measurement, an attenuated total reflection (ATR) method using a crystallite is used, and a map having sufficiently high spatial resolution is created. A fiber cross-sectional distribution of the content of the hydrolysis modifier (component B) is obtained from a map of the IR absorption peak area using a calibration curve prepared in advance. The average value of the hydrolysis regulator (B component) content near the center of the fiber is taken as the content of the hydrolysis regulator (B component) of the resin composition (C component) in the core, and the hydrolysis adjustment of the fiber outer peripheral portion The average value of the agent (B component) content is defined as the content of the hydrolysis regulator (B component) of the resin composition (D component) in the sheath.
As a special carbodiimide, a carbodiimide compound having a carbodiimide group and a cyclic structure in which the first nitrogen and the second nitrogen are bonded by a linking group as disclosed in WO2010 / 071213 The terminal group of the resin and the acidic group generated by decomposition can be sealed, but since the isocyanate compound is not liberated at that time, it may be contained in the resin composition (D component) of the sheath. In addition, as a compound that does not liberate an isocyanate compound, an epoxy compound, oxazoline, and the like may be contained in the sheath resin composition (component D) to seal the acidic group.
<Amount of acidic end group of core-sheath type composite fiber>
The composite fiber of the present invention has an acidic end group amount of 5 eq / ton or less. When the resin composition (C component) in the core contains a sufficiently large amount of the hydrolysis regulator (B component), the amount of acidic end groups is kept at a sufficiently low concentration.
On the other hand, since the resin composition (D component) of the sheath part is substantially free of the hydrolysis regulator (B component) or its content is small, the acidic end group is a hydrolysis regulator (B component). Remains without reacting. When the amount of the remaining acidic end groups is large, hydrolysis of the resin (A component and A ′ component) having autocatalytic action in hot water is accelerated, and desired decomposition characteristics cannot be obtained.
From this viewpoint, the acidic end group amount of the composite fiber is preferably 5 eq / ton or less, more preferably 3 eq / ton or less, further preferably 2 eq / ton or less, and most preferably 1.5 eq / ton or less.
On the other hand, from the viewpoint of reducing process contamination by a compound having an isocyanate group, a state in which acidic end groups remain to some extent is preferable. Accordingly, the acidic end group of the composite fiber is preferably 0.05 eq / ton or more, and more preferably 0.1 eq / ton or more.
<Additives>
The resin composition (refers to both the resin composition (C component) and the resin composition (D component)) may contain known additives and fillers as long as the effects of the invention are not lost. For example, a stabilizer, a crystallization accelerator, a filler, a release agent, an antistatic agent, a plasticizer, an impact resistance improver, a terminal blocking agent, a compatibilizing agent, and the like can be given.
As for the additive, from the viewpoint of not losing the effect of the invention, a component that accelerates the decomposition of the autocatalytic resin (component A) mainly composed of a water-soluble monomer, such as a phosphoric acid component or a resin composition It is important to reduce the effect by not using phosphite-based additives that decompose in materials to produce phosphoric acid components, or by reducing or deactivating as much as possible. . For example, the method of using together the component which deactivates or suppresses them together with a hydrolysis regulator (B component) etc. can be taken suitably.
<Stabilizer>
The resin composition can contain a stabilizer. As a stabilizer, what is used for the stabilizer of a normal thermoplastic resin can be used. For example, an antioxidant, a light stabilizer, etc. can be mentioned. By blending these agents, a molded product having excellent mechanical properties, moldability, heat resistance and durability can be obtained.
Examples of the antioxidant include hindered phenol compounds, hindered amine compounds, phosphite compounds, thioether compounds, and the like.
Examples of hindered phenol compounds include n-octadecyl-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) -propionate, n-octadecyl-3- (3′-methyl-5 ′). -Tert-butyl-4'-hydroxyphenyl) -propionate, n-tetradecyl-3- (3 ', 5'-di-tert-butyl-4'-hydroxyphenyl) -propionate, 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionate], 1,4-butanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -Propionate], 2,2'-methylene-bis (4-methyl-tert-butylphenol), triethylene glycol-bis [3- (3-t ert-butyl-5-methyl-4-hydroxyphenyl) -propionate], tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionate] methane, 3,9-bis [2- {3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro (5,5) undecane Etc.
As a hindered amine compound, N, N′-bis-3- (3 ′, 5′-di-tert-butyl-4′-hydroxyphenyl) propionylhexamethylenediamine, N, N′-tetramethylene-bis [3- (3′-Methyl-5′-tert-butyl-4′-hydroxyphenyl) propionyl] diamine, N, N′-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) -propionyl ] Hydrazine, N-salicyloyl-N'-salicylidenehydrazine, 3- (N-salicyloyl) amino-1,2,4-triazole, N, N'-bis [2- {3- (3,5-di -Tert-butyl-4-hydroxyphenyl) propionyloxy} ethyl] oxyamide and the like. Preferably, triethylene glycol-bis [3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) -propionate] and tetrakis [methylene-3- (3 ′, 5′-di-tert-butyl) -4-hydroxyphenyl) propionate] methane and the like.
As the phosphite compound, those in which at least one P—O bond is bonded to an aromatic group are preferable. Specifically, tris (2,6-di-tert-butylphenyl) phosphite, tetrakis ( 2,6-di-tert-butylphenyl) 4,4′-biphenylene phosphite, bis (2,6-di-tert-butyl-4-methylphenyl) pentaerythritol-di-phosphite, 2,2-methylenebis (4,6-di-tert-butylphenyl) octyl phosphite, 4,4′-butylidene-bis (3-methyl-6-tert-butylphenyl-di-tridecyl) phosphite, 1,1,3-tris (2-methyl-4-ditridecyl phosphite-5-tert-butylphenyl) butane, tris (mixed mono and di-noni) Phenyl) phosphite, tris (nonylphenyl) phosphite, 4,4′-isopropylidenebis (phenyl-dialkylphosphite), 2,4,8,10-tetra-tert-butyl-6- [3- (3 -Methyl-4-hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphosphine “Sumilyzer (registered trademark) GP” and the like.
Specific examples of thioether compounds include dilauryl thiodipropionate, ditridecyl thiodipropionate, dimyristyl thiodipropionate, distearyl thiodipropionate, pentaerythritol-tetrakis (3-lauryl thiopropionate), Pentaerythritol-tetrakis (3-dodecylthiopropionate), pentaerythritol-tetrakis (3-octadecylthiopropionate), pentaerythritol tetrakis (3-myristylthiopropionate), pentaerythritol-tetrakis (3-stearylthio) Propionate) and the like.
Specific examples of the light stabilizer include benzophenone compounds, benzotriazole compounds, aromatic benzoate compounds, oxalic acid anilide compounds, cyanoacrylate compounds, hindered amine compounds, and the like.
Examples of the benzophenone compounds include benzophenone, 2,4-dihydroxybenzophenone, 2,2′-dihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2 ′. -Dihydroxy-4,4'-dimethoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 5-chloro-2-hydroxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-methoxy -2'-carbo Shi benzophenone, 2-hydroxy-4- (2-hydroxy-3-methyl - acryloxy-isopropoxyphenyl) benzophenone.
Examples of the benzotriazole compound include 2- (5-methyl-2-hydroxyphenyl) benzotriazole, 2- (3,5-di-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- (3,5- Di-tert-amyl-2-hydroxyphenyl) benzotriazole, 2- (3 ′, 5′-di-tert-butyl-4′-methyl-2′-hydroxyphenyl) benzotriazole, 2- (3,5- Di-tert-amyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (5-tert-butyl-2-hydroxyphenyl) benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (Α, α-Dimethylbenzyl) phenyl] benzotriazole, 2- [2′-hydroxy-3 ′, 5′-bis (α, α-dimethylben ) Phenyl] -2H- benzotriazole, 2- (4'-octoxy-2'-hydroxyphenyl) benzotriazole.
Examples of the aromatic benzoate compounds include alkylphenyl salicylates such as p-tert-butylphenyl salicylate and p-octylphenyl salicylate.
Examples of oxalic acid anilide compounds include 2-ethoxy-2′-ethyloxalic acid bisanilide, 2-ethoxy-5-tert-butyl-2′-ethyloxalic acid bisanilide, and 2-ethoxy-3′-. Examples include dodecyl oxalic acid bisanilide.
Examples of the cyanoacrylate compound include ethyl-2-cyano-3,3′-diphenyl acrylate and 2-ethylhexyl-cyano-3,3′-diphenyl acrylate.
Examples of hindered amine compounds include 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, 4-acryloyloxy-2,2,6, 6-tetramethylpiperidine, 4- (phenylacetoxy) -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, 4-methoxy-2,2, 6,6-tetramethylpiperidine, 4-octadecyloxy-2,2,6,6-tetramethylpiperidine, 4-cyclohexyloxy-2,2,6,6-tetramethylpiperidine, 4-benzyloxy-2,2 , 6,6-tetramethylpiperidine, 4-phenoxy-2,2,6,6-tetramethylpiperidine, 4- (ethylcarba Yloxy) -2,2,6,6-tetramethylpiperidine, 4- (cyclohexylcarbamoyloxy) -2,2,6,6-tetramethylpiperidine, 4- (phenylcarbamoyloxy) -2,2,6,6 -Tetramethylpiperidine, bis (2,2,6,6-tetramethyl-4-piperidyl) carbonate, bis (2,2,6,6-tetramethyl-4-piperidyl) oxalate, bis (2,2,6 , 6-tetramethyl-4-piperidyl) malonate, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (2,2,6,6-tetramethyl-4-piperidyl) adipate, Bis (2,2,6,6-tetramethyl-4-piperidyl) terephthalate, 1,2-bis (2,2,6,6-tetramethyl-4-piperidylo Cis) -ethane, α, α′-bis (2,2,6,6-tetramethyl-4-piperidyloxy) -p-xylene, bis (2,2,6,6-tetramethyl-4-piperidyl) -Tolylene-2,4-dicarbamate, bis (2,2,6,6-tetramethyl-4-piperidyl) -hexamethylene-1,6-dicarbamate, tris (2,2,6,6-tetramethyl -4-piperidyl) -benzene-1,3,5-tricarboxylate, tris (2,2,6,6-tetramethyl-4-piperidyl) -benzene-1,3,4-tricarboxylate, 1- “2- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine, 1,2,3,4-butanetetracarboxylic acid And 1, 2, 2, 6 Condensation product of 6-pentamethyl-4-piperidinol and β, β, β ′, β′-tetramethyl-3,9- [2,4,8,10-tetraoxaspiro (5,5) undecane] dimethanol Etc.
In this invention, a stabilizer component may be used by 1 type and may be used in combination of 2 or more type. In addition, a hindered phenol compound and / or a benzotriazole compound is preferable as the stabilizer component.
The content of the stabilizer is preferably 0.01 to 3 parts by weight, more preferably 0.03 to 2 parts by weight, per 100 parts by weight of the resin (component A) having an autocatalytic action.
<Crystallization accelerator>
The resin composition can contain an organic or inorganic crystallization accelerator. By containing the crystallization accelerator, a molded product having excellent mechanical properties, heat resistance, and moldability can be obtained.
That is, by applying the crystallization accelerator, moldability and crystallinity are improved, and a molded product that is sufficiently crystallized even in normal injection molding and excellent in heat resistance and moist heat resistance can be obtained. In addition, the manufacturing time for manufacturing the molded product can be greatly shortened, and the economic effect is great.
As the crystallization accelerator, those generally used as crystallization nucleating agents for crystalline resins can be used, and both inorganic crystallization nucleating agents and organic crystallization nucleating agents can be used.
As inorganic crystallization nucleating agents, talc, kaolin, silica, synthetic mica, clay, zeolite, graphite, carbon black, zinc oxide, magnesium oxide, titanium oxide, calcium carbonate, calcium sulfate, barium sulfate, calcium sulfide, boron nitride , Montmorillonite, neodymium oxide, aluminum oxide, phenylphosphonate metal salt and the like. These inorganic crystallization nucleating agents are treated with various dispersing aids in order to enhance the dispersibility in the composition and its effect, and are highly dispersed in a primary particle size of about 0.01 to 0.5 μm. Are preferred.
Organic crystallization nucleating agents include calcium benzoate, sodium benzoate, lithium benzoate, potassium benzoate, magnesium benzoate, barium benzoate, calcium oxalate, disodium terephthalate, dilithium terephthalate, dipotassium terephthalate, Sodium laurate, potassium laurate, sodium myristate, potassium myristate, calcium myristate, barium myristate, sodium octacolate, calcium octacolate, sodium stearate, potassium stearate, lithium stearate, calcium stearate, magnesium stearate , Barium stearate, sodium montanate, calcium montanate, sodium toluate, sodium salicylate, potassium salicylate, salicy Organic carboxylic acid metal salts such as zinc acid, aluminum dibenzoate, β-naphthoic acid sodium, β-naphthoic acid potassium, sodium cyclohexanecarboxylic acid and the like, and organic sulfonic acid metal salts such as sodium p-toluenesulfonate and sodium sulfoisophthalate. Can be mentioned.
Also, organic carboxylic acid amides such as stearic acid amide, ethylenebislauric acid amide, palmitic acid amide, hydroxystearic acid amide, erucic acid amide, trimesic acid tris (tert-butylamide), low density polyethylene, high density polyethylene, polyiso Propylene, polybutene, poly-4-methylpentene, poly-3-methylbutene-1, polyvinylcycloalkane, polyvinyltrialkylsilane, branched polylactic acid, sodium salt of ethylene-acrylic acid copolymer, sodium of styrene-maleic anhydride copolymer Examples thereof include salts (so-called ionomers), benzylidene sorbitol and derivatives thereof such as dibenzylidene sorbitol.
Among these, at least one selected from talc and organic carboxylic acid metal salts is preferably used. Only one type of crystallization accelerator may be used in the present invention, or two or more types may be used in combination.
The content of the crystallization accelerator is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight per 100 parts by weight of the resin (component A) having an autocatalytic action.
<Filler>
The resin composition can contain an organic or inorganic filler. By containing the filler component, a molded product having excellent mechanical properties, heat resistance, and moldability can be obtained.
Organic fillers such as rice husks, wood chips, okara, waste paper ground materials, clothing ground materials, cotton fibers, hemp fibers, bamboo fibers, wood fibers, kenaf fibers, jute fibers, banana fibers, coconut fibers Plant fibers such as pulp or cellulose fibers processed from these plant fibers and fibrous fibers such as animal fibers such as silk, wool, angora, cashmere and camel, synthetic fibers such as polyester fibers, nylon fibers and acrylic fibers , Paper powder, wood powder, cellulose powder, rice husk powder, fruit husk powder, chitin powder, chitosan powder, protein, starch and the like. From the viewpoint of moldability, powdery materials such as paper powder, wood powder, bamboo powder, cellulose powder, kenaf powder, rice husk powder, fruit husk powder, chitin powder, chitosan powder, protein powder, and starch are preferred. Powder, bamboo powder, cellulose powder and kenaf powder are preferred. Paper powder and wood powder are more preferable. Paper dust is particularly preferable.
These organic fillers may be those directly collected from natural products, but may also be those obtained by recycling waste materials such as waste paper, waste wood and old clothes.
The wood is preferably a softwood material such as pine, cedar, oak or fir, or a hardwood material such as beech, shii or eucalyptus.
Paper powder is an adhesive from the viewpoint of moldability, especially emulsion adhesives such as vinyl acetate resin emulsions and acrylic resin emulsions that are usually used when processing paper, polyvinyl alcohol adhesives, polyamide adhesives Those containing hot melt adhesives such as are preferably exemplified.
The content of the organic filler is not particularly limited, but from the viewpoint of moldability and heat resistance, it is preferably 0.1 to 20 parts by weight, preferably 100 to 20 parts by weight per 100 parts by weight of the resin (component A) having autocatalytic action. The amount is more preferably 0.5 to 15 parts by weight, further preferably 10 to 150 parts by weight, and particularly preferably 1 to 10 parts by weight.
When the content of the organic filler is less than 0.1 parts by weight, the effect of improving the moldability of the composition is small, and when it exceeds 20 parts by weight, uniform dispersion of the filler becomes difficult, or the moldability and heat resistance are increased. In addition to the properties, the strength and appearance of the material may decrease, which is not preferable.
The resin composition may contain an inorganic filler. By containing the inorganic filler, a resin composition having excellent mechanical properties, heat resistance, and moldability can be obtained. As the inorganic filler used in the present invention, a fibrous, plate-like, or powder-like material used for reinforcing ordinary thermoplastic resins can be used.
Specifically, for example, carbon nanotube, glass fiber, asbestos fiber, carbon fiber, graphite fiber, metal fiber, potassium titanate whisker, aluminum borate whisker, magnesium whisker, silicon whisker, wollastonite, imogolite, sepiolite, Asbestos, slag fiber, zonolite, gypsum fiber, silica fiber, silica-alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, and other fibrous inorganic fillers, layered silicate, and organic onium ions Layered silicate, glass flake, non-swelling mica, graphite, metal foil, ceramic beads, talc, clay, mica, sericite, zeolite, bentonite, dolomite, kaolin, powdered silicic acid, feldspar powder, potassium titanate, shirasuba Plates and particles of inorganic fillers such as carbon nanoparticles such as carbon, calcium carbonate, magnesium carbonate, barium sulfate, calcium oxide, aluminum oxide, titanium oxide, aluminum silicate, silicon oxide, gypsum, novaculite, dosonite and white clay fullerene Agents.
Specific examples of layered silicates include smectite clay minerals such as montmorillonite, beidellite, nontronite, saponite, hectorite, and soconite, various clay minerals such as vermiculite, halosite, kanemite, and kenyanite, Li-type fluorine teniolite, Na And swellable mica such as Li-type fluorine teniolite, Li-type tetrasilicon fluorine mica and Na-type tetrasilicon fluorine mica. These may be natural or synthetic. Among these, smectite clay minerals such as montmorillonite and hectorite, and swellable synthetic mica such as Li type fluorine teniolite and Na type tetrasilicon fluorine mica are preferable.
Among these inorganic fillers, fibrous or plate-like inorganic fillers are preferable, and glass fiber, wollastonite, aluminum borate whisker, potassium titanate whisker, mica, and kaolin, a cation-exchanged layered silicate. Is preferred. The aspect ratio of the fibrous filler is preferably 5 or more, more preferably 10 or more, and further preferably 20 or more.
Such a filler may be coated or converged with a thermoplastic resin such as an ethylene / vinyl acetate copolymer or a thermosetting resin such as an epoxy resin, or may be treated with a coupling agent such as aminosilane or epoxysilane. May be.
The content of the inorganic filler is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, and further preferably 10 to 150 parts by weight per 100 parts by weight of the resin (component A) having an autocatalytic action. Part by weight, particularly preferably 1 to 10 parts by weight.
<Release agent>
The resin composition can contain a release agent. As the mold release agent, those used for ordinary thermoplastic resins can be used.
Specific examples of release agents include fatty acids, fatty acid metal salts, oxy fatty acids, paraffins, low molecular weight polyolefins, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid partial saponified esters, fatty acid lower alcohol esters, fatty acid polyvalents. Examples include alcohol esters, fatty acid polyglycol esters, and modified silicones. By blending these, a polylactic acid molded product excellent in mechanical properties, moldability, and heat resistance can be obtained.
Fatty acids having 6 to 40 carbon atoms are preferred. Specifically, oleic acid, stearic acid, lauric acid, hydroxystearic acid, behenic acid, arachidonic acid, linoleic acid, linolenic acid, ricinoleic acid, palmitic acid, montan Examples thereof include acids and mixtures thereof. The fatty acid metal salt is preferably an alkali metal salt or alkaline earth metal salt of a fatty acid having 6 to 40 carbon atoms, and specific examples include calcium stearate, sodium montanate, calcium montanate, and the like.
Examples of the oxy fatty acid include 1,2-oxystearic acid. Paraffin having 18 or more carbon atoms is preferable, and examples thereof include liquid paraffin, natural paraffin, microcrystalline wax, petrolactam and the like.
As the low molecular weight polyolefin, for example, those having a molecular weight of 5,000 or less are preferable, and specific examples include polyethylene wax, maleic acid-modified polyethylene wax, oxidized type polyethylene wax, chlorinated polyethylene wax, and polypropylene wax. Fatty acid amides having 6 or more carbon atoms are preferred, and specific examples include oleic acid amide, erucic acid amide, and behenic acid amide.
The alkylene bis fatty acid amide is preferably one having 6 or more carbon atoms, and specifically includes methylene bis stearic acid amide, ethylene bis stearic acid amide, N, N-bis (2-hydroxyethyl) stearic acid amide and the like. As the aliphatic ketone, those having 6 or more carbon atoms are preferable, and examples thereof include higher aliphatic ketones.
Examples of the fatty acid partial saponified ester include a montanic acid partial saponified ester. Examples of the fatty acid lower alcohol ester include stearic acid ester, oleic acid ester, linoleic acid ester, linolenic acid ester, adipic acid ester, behenic acid ester, arachidonic acid ester, montanic acid ester, isostearic acid ester and the like.
Examples of fatty acid polyhydric alcohol esters include glycerol tristearate, glycerol distearate, glycerol monostearate, pentaerythritol tetrastearate, pentaerythritol tristearate, pentaerythritol distearate, pentaerythrul Examples include tall monostearate, pentaerythritol adipate stearate, sorbitan monobehenate and the like. Examples of fatty acid polyglycol esters include polyethylene glycol fatty acid esters and polypropylene glycol fatty acid esters.
Examples of the modified silicone include polyether-modified silicone, higher fatty acid alkoxy-modified silicone, higher fatty acid-containing silicone, higher fatty acid ester-modified silicone, methacryl-modified silicone, and fluorine-modified silicone.
Of these, fatty acid, fatty acid metal salt, oxy fatty acid, fatty acid ester, fatty acid partial saponified ester, paraffin, low molecular weight polyolefin, fatty acid amide, and alkylene bis fatty acid amide are preferred, and fatty acid partial saponified ester and alkylene bis fatty acid amide are more preferred. Of these, montanic acid ester, montanic acid partially saponified ester, polyethylene wax, acid value polyethylene wax, sorbitan fatty acid ester, erucic acid amide, and ethylene bisstearic acid amide are preferable, and particularly, montanic acid partially saponified ester and ethylene bisstearic acid amide preferable.
A mold release agent may be used by 1 type and may be used in combination of 2 or more type. The content of the release agent is preferably 0.01 to 3 parts by weight, and more preferably 0.03 to 2 parts by weight with respect to 100 parts by weight of the resin (component A) having an autocatalytic action.
<Antistatic agent>
The resin composition can contain an antistatic agent. Examples of the antistatic agent include quaternary ammonium salt compounds such as (β-lauramidopropionyl) trimethylammonium sulfate and sodium dodecylbenzenesulfonate, sulfonate compounds, and alkyl phosphate compounds.
In the present invention, the antistatic agent may be used alone or in combination of two or more. The content of the antistatic agent is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the resin (component A) having an autocatalytic action.
<Plasticizer>
The resin composition can contain a plasticizer. As the plasticizer, generally known plasticizers can be used. Examples include polyester plasticizers, glycerin plasticizers, polycarboxylic acid ester plasticizers, phosphate ester plasticizers, polyalkylene glycol plasticizers, and epoxy plasticizers.
As a polyester plasticizer, acid components such as adipic acid, sebacic acid, terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid and ethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, Examples thereof include polyesters composed of diol components such as 1,4-butanediol, 1,6-hexanediol and diethylene glycol, and polyesters composed of hydroxycarboxylic acid such as polycaprolactone. These polyesters may be end-capped with a monofunctional carboxylic acid or a monofunctional alcohol.
Examples of the glycerol plasticizer include glycerol monostearate, glycerol distearate, glycerol monoacetomonolaurate, glycerol monoacetomonostearate, glycerol diacetomonooleate, and glycerol monoacetomonomontanate.
Polyvalent carboxylic acid plasticizers include dimethyl phthalate, diethyl phthalate, dibutyl phthalate, diheptyl phthalate, dibenzyl phthalate, butyl benzyl phthalate, trimellitic acid tributyl, trimellitic acid trioctyl, Trimellitic acid esters such as trihexyl meritate, isodecyl adipate, adipic acid esters such as adipate-n-decyl-n-octyl, citrate esters such as tributyl acetylcitrate, and bis (2-ethylhexyl) azelate Examples include sebacic acid esters such as azelaic acid ester, dibutyl sebacate, and bis (2-ethylhexyl) sebacate.
Examples of the phosphate ester plasticizer include tributyl phosphate, tris phosphate (2-ethylhexyl), trioctyl phosphate, triphenyl phosphate, tricresyl phosphate, diphenyl-2-ethylhexyl phosphate, and the like.
Polyalkylene glycol plasticizers such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, poly (ethylene oxide-propylene oxide) block and / or random copolymers, ethylene oxide addition polymers of bisphenols, tetrahydrofuran addition polymers of bisphenols, etc. And end-capping compounds such as a terminal epoxy-modified compound, a terminal ester-modified compound, and a terminal ether-modified compound.
Examples of the epoxy plasticizer include an epoxy triglyceride composed of alkyl epoxy stearate and soybean oil, and an epoxy resin using bisphenol A and epichlorohydrin as raw materials.
Specific examples of other plasticizers include benzoic acid esters of aliphatic polyols such as neopentyl glycol dibenzoate, diethylene glycol dibenzoate, triethylene glycol-bis (2-ethylbutyrate), and fatty acids such as stearamide. Fatty acid esters such as amides and butyl oleate, oxy acid esters such as methyl acetylricinoleate and butyl acetylricinoleate, pentaerythritols, fatty acid esters of pentaerythritols, various sorbitols, polyacrylic acid esters, silicone oils, and paraffins Etc.
As the plasticizer, polyester plasticizers, polyalkylene plasticizers, glycerin plasticizers, pentaerythritols, pentaerythritol fatty acid esters can be preferably used, and only one kind can be used. It is also possible to use two or more kinds in combination.
The content of the plasticizer is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 15 parts by weight, and still more preferably 0.1 to 100 parts by weight per 100 parts by weight of the resin (component A) having an autocatalytic action. 10 parts by weight. In the present invention, each of the crystallization nucleating agent and the plasticizer may be used alone, or more preferably used in combination. Moreover, it is most preferable to use what has a plasticizer effect for the hydrolysis regulator essential for this application.
<Impact resistance improver>
The resin composition can contain an impact resistance improver. The impact resistance improver is one that can be used to improve the impact resistance of a thermoplastic resin, and is not particularly limited. For example, at least one selected from the following impact resistance improvers can be used.
Specific examples of impact modifiers include ethylene-propylene copolymers, ethylene-propylene-nonconjugated diene copolymers, ethylene-butene-1 copolymers, various acrylic rubbers, ethylene-acrylic acid copolymers and their Alkali metal salts (so-called ionomers), ethylene-glycidyl (meth) acrylate copolymers, ethylene-acrylate copolymers (for example, ethylene-ethyl acrylate copolymers, ethylene-butyl acrylate copolymers), modified ethylene -Propylene copolymer, diene rubber (eg polybutadiene, polyisoprene, polychloroprene), diene and vinyl copolymer (eg styrene-butadiene random copolymer, styrene-butadiene block copolymer, styrene-butadiene-styrene block copolymer) Coalescence, styrene Soprene random copolymer, styrene-isoprene block copolymer, styrene-isoprene-styrene block copolymer, polybutadiene graft copolymerized with styrene, butadiene-acrylonitrile copolymer), polyisobutylene, isobutylene and butadiene Or a copolymer with isoprene, natural rubber, thiocol rubber, polysulfide rubber, polyurethane rubber, polyether rubber, epichlorohydrin rubber and the like can be mentioned.
In addition, those having various cross-linking degrees, various micro structures such as those having a cis structure, a trans structure, etc., a core layer and one or more shell layers covering the core layer, and adjacent layers are composed of heterogeneous polymers. A so-called core-shell type multi-layered polymer can also be used.
Furthermore, the various (co) polymers mentioned in the above specific examples may be any of random copolymers, block copolymers, block copolymers and the like, and can be used as the impact resistance improver of the present invention.
The content of the impact modifier is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 15 parts by weight, and still more preferably 100 parts by weight of the resin (component A) having autocatalytic action. 1 to 10 parts by weight.
<Compatibilizer>
As a compatibilizing agent, a compound that is compatible with any of the components constituting the core and the sheath, or the ends of both the components constituting the core and the component constituting the sheath. A compound having a cross-linked structure by reacting with is preferably used, but is not limited thereto. For example, the former compatibilizing agent includes a surfactant copolymer having a component similar to the component constituting the core portion and the component constituting the sheath portion, a block copolymer, and the like.
Moreover, as what forms a crosslinked structure, the epoxy compound which has an epoxy group in both ends, an oxazoline compound, an oxazine compound, those copolymers, a carbodiimide compound, those copolymers, etc. are mentioned. When using a cross-linking agent, add the cross-linking agent to either the component constituting the core or the sheath, or both components, and the cross-linking agent reacts with the end groups of each component present in the vicinity of the composite interface This improves the interfacial adhesion.
<Others>
The resin composition may contain a thermosetting resin such as a phenol resin, a melamine resin, a thermosetting polyester resin, a silicone resin, or an epoxy resin within a range not departing from the spirit of the present invention.
In addition, the resin composition may contain a flame retardant such as bromine, phosphorus, silicone, and antimony compound as long as it does not contradict the gist of the present invention.
Also, colorants containing organic and inorganic dyes and pigments, such as oxides such as titanium dioxide, hydroxides such as alumina white, sulfides such as zinc sulfide, ferrocyanides such as bitumen, zinc chromate, etc. Sulfates such as chromate and barium sulfate, carbonates such as calcium carbonate, silicates such as ultramarine, phosphates such as manganese violet, carbon such as carbon black, metal colorants such as bronze powder and aluminum powder, etc. It may be included.
Also, nitroso type such as naphthol green B, nitro type such as naphthol yellow S, azo type such as naphthol red and chromophthal yellow, phthalocyanine type such as phthalocyanine blue and fast sky blue, and condensed polycyclic coloring such as indanthrone blue An additive such as a slidability improver such as a graphite or fluorine resin may be added. These additives can be used alone or in combination of two or more.
<Method for producing resin composition>
The resin composition may contain a hydrolysis regulator (component B) and any known additive.
In addition, when using stereocomplex polylactic acid as resin (A component) which has an autocatalytic action, after mixing poly L-lactic acid and poly D-lactic acid to form stereocomplex polylactic acid, it is a hydrolysis regulator. (B component) and additives may be mixed, a hydrolysis adjusting agent (B component) and additives may be mixed when forming stereocomplex polylactic acid, or poly L-lactic acid during spinning. And poly D-lactic acid and a hydrolysis regulator (component B) and additives may be mixed.
There is no particular limitation on the method of adding and mixing to the resin having the autocatalytic action (component A), and it is added as a master batch of the resin (component A) having the autocatalytic action to be applied by a known method by a conventionally known method. A method, or a method in which a solid of a resin (A component) having autocatalytic action is brought into contact with a liquid in which a hydrolysis regulator (B component) is dissolved, dispersed or melted, and the hydrolysis regulator (B component) is permeated. Can be taken.
When taking the method of adding as a master batch of a solution, a melt or a resin (component A) having an autocatalytic action, a method of adding using a conventionally known kneading apparatus can be taken. In kneading, a kneading method in a solution state or a kneading method in a molten state is preferable from the viewpoint of uniform kneading properties. The kneading apparatus is not particularly limited, and examples thereof include conventionally known vertical reaction vessels, mixing tanks, kneading tanks or uniaxial or multiaxial horizontal kneading apparatuses such as uniaxial or multiaxial ruders and kneaders. The mixing time is not particularly specified, and depends on the mixing apparatus and the mixing temperature, but is selected from 0.1 minutes to 2 hours, preferably 0.2 minutes to 60 minutes, more preferably 0.2 minutes to 30 minutes. .
As a solvent, what is inactive with respect to resin (A component) and a hydrolysis regulator (B component) which have an autocatalytic action can be used. In particular, a solvent that has affinity for both and at least partially dissolves both is preferable.
As the solvent, for example, hydrocarbon solvents, ketone solvents, ester solvents, ether solvents, halogen solvents, amide solvents and the like can be used.
Examples of the hydrocarbon solvent include hexane, cyclohexane, benzene, toluene, xylene, heptane, decane and the like. Examples of ketone solvents include acetone, methyl ethyl ketone, diethyl ketone, cyclohexanone, and isophorone.
Examples of ester solvents include ethyl acetate, methyl acetate, ethyl succinate, methyl carbonate, ethyl benzoate, and diethylene glycol diacetate. Examples of the ether solvent include diethyl ether, dibutyl ether, tetrahydrofuran, dioxane, diethylene glycol dimethyl ether, triethylene glycol diethyl ether, diphenyl ether and the like. Examples of the halogen solvent include dichloromethane, chloroform, tetrachloromethane, dichloroethane, 1,1 ′, 2,2′-tetrachloroethane, chlorobenzene, dichlorobenzene and the like. Examples of the amide solvent include formamide, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone and the like. These solvents may be used alone or as a mixed solvent as desired.
The solvent is applied in the range of 1 to 1,000 parts by weight per 100 parts by weight of the resin composition. If the amount is less than 1 part by weight, there is no significance in applying the solvent. The upper limit of the amount of solvent used is not particularly limited, but is about 1,000 parts by weight from the viewpoints of operability and reaction efficiency.
Hydrolysis modifier (B component) is brought into contact with a liquid in which hydrolysis modifier (B component) is dissolved, dispersed or melted, and a solid of resin (A component) having an autocatalytic action mainly composed of a water-soluble monomer. In the case of taking a method of infiltrating water, a method of bringing a hydrolysis regulator (component B) dissolved in a solvent as described above into contact with a resin (component A) having an autocatalytic action mainly composed of a solid water-soluble monomer. Alternatively, a method of bringing a solid resin (A component) into contact with an emulsion liquid of a hydrolysis regulator (B component) can be used. As a method for contacting, a method of immersing a resin (A component) having an autocatalytic action, a method of applying to a resin (A component) having an autocatalytic action, a method of spraying, and the like can be suitably employed.
The capping reaction of the acidic group of the water autocatalytic resin (component A) by the hydrolysis modifier (component B) is possible at a temperature of room temperature (25 ° C.) to 300 ° C., but from the viewpoint of reaction efficiency. Further promotion is achieved in the range of 50 to 280 ° C., more preferably 100 to 280 ° C. Resin having self-catalytic action (component A) is more likely to react at a melting temperature, but at a temperature lower than 300 ° C. in order to suppress volatilization and decomposition of the hydrolysis regulator (component B). It is preferable to react. Applying a solvent is also effective in reducing the melting temperature of the resin (component A) having autocatalytic action and increasing the stirring efficiency.
Although the reaction proceeds sufficiently rapidly without a catalyst, a catalyst that accelerates the reaction can also be used. As a catalyst, the catalyst generally used with a hydrolysis regulator (B component) is applicable. These can be used alone or in combination of two or more. The addition amount of the catalyst is not particularly limited, but is preferably 0.001 to 1 part by weight, more preferably 0.01 to 0.1 part by weight, more preferably 100 parts by weight of the resin composition. Most preferred is 0.02 to 0.1 parts by weight.
In the present invention, two or more kinds of hydrolysis regulators (component B) may be used in combination. For example, hydrolysis for performing an initial acidic group blocking reaction of a resin (component A) having an autocatalytic action. You may use a separate thing about a regulator (B component) and a hydrolysis regulator (B component) which performs the sealing reaction of the acidic group produced in hot water higher than 135 degreeC.
Furthermore, it is preferable to use an auxiliary for the hydrolysis adjusting agent (component B), that is, an agent for assisting the effect of the component B in order to delay the hydrolysis. As such an agent, any known agent can be used. For example, at least selected from hydrotalcite, alkaline earth metal oxide, alkaline earth metal hydroxide, and alkaline earth metal carbonate. One compound is exemplified. The content of the auxiliary agent is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts by weight, still more preferably 0.7 to 10 parts by weight per 100 parts by weight of the hydrolysis regulator (component B). It is.
<Method for producing core-sheath type composite fiber>
The manufacturing method of the core-sheath-type conjugate fiber of the present invention discharges the resin composition (C component) melted from the nozzle forming the core part, and the resin composition (D component) melted from the nozzle forming the sheath part. Including a spinning process of discharging. (A) The resin composition (component C) contains an autocatalytic resin (component A) and a hydrolysis regulator (component B), and the content of the hydrolysis modifier (component B) is the total weight. 1 to 40 parts by weight based on the above. (B) The resin composition (component D) contains substantially no hydrolysis modifier (component B) in the resin (A ′ component) having an autocatalytic action.
(spinning)
The fiber of the present invention may be obtained by ordinary melt spinning and then post-processed.
The resin composition (C component) and the resin composition (D component) were melted by an extruder type or pressure melter type melt extruder, then weighed by a gear pump, filtered in a pack, and then provided to the base. It is discharged from the nozzle as a monofilament, multifilament or the like.
At this time, the resin having the autocatalytic action (component A), the hydrolysis adjusting agent (component B), and the additive may be kneaded in advance, or melted separately by dry blending or other addition methods. You may supply to an extruder. In particular, the hydrolysis regulator (component B) may be supplied in a solid or liquid state. Specific supply methods include known methods such as a table feeder, a disk feeder, a screw feeder, a tube pump, a diaphragm pump, a gear pump, and a plunger pump.
The shape of the base and the number of bases are not particularly limited. The discharged yarn is immediately cooled and solidified, then converged, applied with oil, and wound. The winding speed is not particularly limited, but is preferably in the range of 100 m / min to 10,000 m / min.
Since the composite fiber of the present invention contains a hydrolysis regulator (component B) only in the core during spinning, in the state of the fiber before use in hot water, compared to the fiber spun in a single layer. There is a tendency that the concentration difference of the hydrolysis adjusting agent (component B) is large between the core and the sheath. The specific difference in concentration is preferably 0.1 to 20%, more preferably 0.2 to 15%, still more preferably 0.3 to 10%, and most preferably 0.4 between the fiber core and the sheath. ~ 5%. The more the concentration difference is greater than 0.1%, the smaller the amount of leakage of the isocyanate compound and the hydrolysis regulator (B component) itself out of the fiber, and when it is less than 20%, the hydrolysis regulator is the fiber surface layer. It fully diffuses and shows good hydrolysis performance.
The discharge ratio between the core and the sheath preferably satisfies the following formula (I). When the following formula is satisfied, the thickness of the sheath part at the time of discharge becomes sufficiently thick, so that the partial omission of the sheath part or the compound having an isocyanate group through the sheath part and the hydrolysis regulator (component B) itself are processed. Leakage to the outside of the fiber at the time can be further suppressed.

(However, in the formula, Qc: discharge amount of the core portion, Qs: discharge amount of the sheath portion, D: diameter of the discharge port)
(Stretching)
The spun undrawn yarn can be used as it is, but can also be used after being drawn. When used in an unstretched state, it may be subjected to a crystallization treatment by performing a heat treatment at a temperature below the melting point after spinning and before winding. For the heat treatment, any method such as a hot roller, a contact heater, a non-contact hot plate, or a heat medium bath can be adopted. Moreover, you may employ | adopt crystallization methods, such as being immersed in a solvent.
When stretching is performed, the spinning step and the stretching step are not necessarily separated from each other, and a direct spinning stretching method in which stretching is performed without winding once after spinning may be employed.
The stretching may be one-stage stretching or multi-stage stretching of two or more stages. From the viewpoint of producing a high-strength fiber, the stretching ratio is preferably 3 times or more, and more preferably 4 times or more. On the other hand, from the viewpoint of producing a low-oriented fiber, it is preferably less than 3 times, and more preferably less than 2 times. As described above, as for the draw ratio, appropriate conditions are selected in combination with other drawing conditions such as drawing temperature and drawing speed from the viewpoint of desired fiber strength, crystallization speed, degree of orientation, and the like.
As a preheating method for stretching, in addition to roll temperature rise, a flat or pin-like contact heater, non-contact hot plate, heating medium bath, and the like can be used, and a commonly used method may be used. The stretching temperature is selected, for example, in the range of 40 to 130 ° C., preferably 50 to 120 ° C., particularly preferably 60 to 110 ° C.
(Heat treatment)
Following the stretching, it is preferable that a heat treatment is performed at a temperature lower than the melting point before winding. For the heat treatment, any method such as a hot roller, a contact heater, a non-contact hot plate, or a heat medium bath can be adopted.
As the heat treatment temperature, for example, a range of 100 to 220 ° C., preferably 110 to 210 ° C., particularly preferably 120 to 200 ° C. is selected. In the heat treatment, the melting point can be improved by increasing in steps near the melting point.
Further, after the stretching treatment, a relaxation treatment can be performed after the heat treatment. Further, after the relaxation treatment, the stretching treatment may be performed again, or the relaxation treatment may be performed a plurality of times.
(Cut, crimped)
The core-sheath type composite fiber of the present invention may be a short fiber. When producing short fibers, in addition to the method of drawing with long fibers, a step of cutting with a rotary cutter or the like into a predetermined fiber length according to the application, and if further crimping is required, constant length heat treatment and A step of imparting crimp with an indentation crimper or the like is added during the relaxation heat treatment. In that case, in order to improve crimp imparting property, it can preheat before crimper using water vapor | steam, an electric heater, etc. FIG.
Further, after stretching, by heat-setting at 170 ° C. to 220 ° C. under tension, a polylactic acid fiber having high stereo complex crystallinity (S), low heat shrinkage and strength of 3.5 cN / dTex or more is obtained. It can also be obtained.
(Sealing of acidic end groups)
The core-sheath type composite fiber of the present invention is a resin having an autocatalytic action due to diffusion of the hydrolysis regulator (component B) in the fiber by spinning, drawing, heating during heat setting, and heating during use. The desired decomposition behavior is exhibited by sealing the acidic end groups of the A component and the A ′ component).
In the present invention, heating refers to a process of heating the fiber, and includes a stretching process or a heat setting process. Heating is carried out within a range in which the compound having an isocyanate group and the hydrolysis modifier (B component) itself produced by the reaction in which the hydrolysis modifier (B component) binds to the terminal of the polymer compound does not leak out of the fiber. It is preferable. Specifically, when processing in the atmosphere, it is performed in a range of 60 ° C. to 220 ° C., in the case of 60 ° C. to 120 ° C., within 30 seconds to 10 minutes, and in the case of 120 ° C. to 220 ° C., 1 second or more 1 It is preferable to carry out in a short time within minutes.
Heating can be preferably carried out in water in order to prevent the compound having an isocyanate group and the hydrolysis regulator (component B) from leaking out of the fiber. When carried out in water, it is preferably 1 hour to 72 hours at 40 ° C. to 60 ° C. and 30 seconds to 3 hours at 60 ° C. to 100 ° C. from the viewpoint of preventing excessive hydrolysis. In order to suppress leakage of the compound having an isocyanate group and the hydrolysis regulator (component B) to the outside of the fiber, it can be carried out in a fluid sufficiently containing the hydrolysis regulator, or in a pressurized gas or pressurized water.
<Characteristics of core-sheath fiber>
The core-sheath type composite fiber of the present invention desirably satisfies any of the following A1 to A3.
A1: In hot water at an arbitrary temperature of 135 ° C. to 160 ° C., after 3 hours, acidic groups derived from the resin composition are 30 equivalents / ton or less and the weight of the non-water-soluble content of the resin composition is 50% or more and 24 hours. Later, the weight of the non-water content of the resin composition is 50% or less.
A2: In hot water at an arbitrary temperature of 160 ° C. to 180 ° C., after 2 hours, acidic groups derived from the resin composition are 30 equivalents / ton or less and the weight of the non-water-soluble content of the resin composition is 50% or more and 24 hours. Later, the weight of the non-water content of the resin composition is 50% or less.
A3: In hot water at an arbitrary temperature of 180 ° C. to 220 ° C., the acidic group derived from the resin composition is 30 equivalents / ton or less after 1 hour, and the weight of the non-aqueous component of the resin composition is 50% or more and 24 hours. Later, the weight of the non-water content of the resin composition is 50% or less.
The range in which the core-sheath fiber of the present invention can be suitably used varies depending on the temperature. Further, in A1 to A3, the time earlier than the specified fixed period (1 hour, 2 hours, 3 hours) is that the acidic group derived from the resin composition is 30 equivalents / ton or less and the weight of the non-aqueous component is 50% or more. Preferably there is. The weight of the non-aqueous component is more preferably 70% or more, further preferably 80% or more, and most preferably 90% or more.
In A1, the fixed period is 3 hours, during which the fiber weight and shape are maintained. Further, from the viewpoint of exerting desired performance in an oil field excavation technique or the like, in a hot water at an arbitrary temperature of 135 ° C. to 160 ° C., a resin composition after a certain period longer than 2 hours as defined in the present invention. The acidic group derived from the product may be 30 equivalent / ton or less and the weight of the non-aqueous component may be 50% or more.
In A2, the fixed period is 2 hours, and the weight and shape of the fiber are maintained during that period. Further, from the viewpoint of exerting desired performance in an oil field excavation technique or the like, in a hot water at an arbitrary temperature of 160 ° C. to 180 ° C., a resin composition after a certain period longer than 2 hours as defined in the present invention. The acidic group derived from the product may be 30 equivalent / ton or less and the weight of the non-aqueous component may be 50% or more.
In A3, the fixed period is 1 hour, and during this time, the weight and shape of the fiber are retained. From the viewpoint of exerting desired performance in an oil field drilling technique or the like, it is derived from the resin composition after a certain period longer than 1 hour defined in the present invention in hot water at an arbitrary temperature of 180 ° C. to 220 ° C. The acid group may be 30 equivalent / ton or less and the weight of the non-water-soluble content of the resin composition may be 50% or more.
After a certain period of time defined in A1 to A3 (1 hour, 2 hours, 3 hours), the effect of blocking the acidic group of the component B disappears, and the decomposition of the resin is promoted by the autocatalytic action of the acidic group. The group concentration increases exponentially. Further, as the decomposition proceeds, the resin becomes a water-soluble monomer and dissolves in water. It is suitable when using the fibers of the present invention, such as in an oil field drilling technique, that the phenomenon occurs as soon as possible after maintaining the weight and shape of the fibers for a period of time. Therefore, it is preferable that the weight of the non-water content of the resin composition is 50% or less after 24 hours. For the above reasons, the weight of the water-insoluble content of the resin composition after 18 hours is more preferably 50% or less, and the content of the water-insoluble content of the resin composition after 12 hours is more preferably 50% or less, More preferably, the weight of the non-water content of the resin composition is 50% or less after 6 hours.
The core-sheath type composite fiber of the present invention preferably has a water-insoluble content of 10% or less after 100 hours in hot water at an arbitrary temperature of 135 ° C. to 220 ° C. For example, when the fiber of the present invention is used in an oil field excavation technique or the like, the fiber can work effectively by dissolving in water quickly after maintaining its weight and shape for a certain period of time. Therefore, it is preferable that the weight of the non-water-soluble content of the resin composition is 10% or less after 100 hours in hot water at an arbitrary temperature of 135 ° C. to 220 ° C. Further, from the viewpoint of exerting treatment in water after use and desired performance, the less water-insoluble content is better, and the weight of water-insoluble content after 100 hours is more preferably 5% or less, and 1% or less. More preferably it is.
<Shape of core-sheath type composite fiber>
The thickness of the sheath portion of the core-sheath type composite fiber of the present invention is preferably 0.1 to 20 μm, more preferably 0.2 to 15 μm, still more preferably 0.3 to 10 μm, and most preferably 0.4 to 5 μm. . When the thickness is greater than 0.1 μm, leakage of the compound having an isocyanate group and the hydrolysis regulator (component B) itself during processing can be further suppressed. On the other hand, when the thickness is less than 20 μm, the hydrolysis adjusting agent sufficiently diffuses to the fiber surface layer and exhibits good hydrolysis performance.
As the fiber cross section, the ratio A: B = 20: 80 to 95: 5 of the area A of the core and the area B of the sheath is preferable, more preferably 30:70 to 90:10, and still more preferably 40:60. ~ 80: 20, most preferably 50:50 to 70:30. When the area ratio of the sheath is 5% or more, leakage of the compound having an isocyanate group and the hydrolysis regulator (B component) itself during processing can be further suppressed. On the other hand, when the area ratio of the sheath portion is 80% or less, the hydrolysis adjusting agent sufficiently diffuses to the fiber surface layer, and exhibits good hydrolysis performance.
The above-described thickness and area ratio of the sheath are appropriately adjusted depending on the desired hydrolysis behavior, heat treatment conditions and use conditions.
In addition, the cross-sectional shape of the composite fiber may be any of a round cross-section, a polygon cross-section, a multi-leaf cross-section, a hollow cross-section, and other known cross-sectional shapes. It may be. Furthermore, it may be a single-core type with a positive core (concentric) or a single-core type with an eccentricity (eccentricity).
Further, the core-sheath structure may have a layer structure of three or more layers having an intermediate part between the core part and the sheath part. In this case, at least the outermost sheath part is substantially a hydrolysis modifier (B It is important that no component is included.
<Others>
The core-sheath type composite fiber of the present invention may be used alone or in combination with other types of fibers as long as the object is achieved. In addition to various combinations with fiber structures composed of other types of fibers, mixed modes include mixed yarns with other fibers, composite false twisted yarns, mixed spun yarns, long and short composite yarns, fluid processed yarns, covering yarns, and twisted yarns. , Mixed cotton, and the like. When mixed, the mixing ratio is selected from the range of 1% by weight or more, more preferably 10% by weight or more, and further preferably 30% by weight or more in order to exhibit the characteristics of the resin composition.
Examples of other fibers used in combination include cellulose fibers such as cotton, hemp, rayon, and tencel, wool, silk, acetate, polyester, nylon, acrylic, vinylon, polyolefin, and polyurethane.

Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited thereto. Each physical property was measured by the following methods.
(1) Weight average molecular weight (Mw) and number average molecular weight (Mn):
The weight average molecular weight and number average molecular weight of the polymer were measured by gel permeation chromatography (GPC) and converted to standard polystyrene.
For GPC measurement, 10 μl of a sample of 1 mg / ml (chloroform containing 1% hexafluoroisopropanol) at a temperature of 40 ° C. and a flow rate of 1.0 ml / min was used with the following detector and column. Injected and measured.
Detector: Differential refractometer (manufactured by Shimadzu Corporation) RID-6A.
Column: Toso-Co., Ltd. TSKgelG3000HXL, TSKgelG4000HXL, TSKgelG5000HXL and TSKguardcolumnHXL-L connected in series, or Toso- Co., Ltd. TSKgelG2000HXL, TSKgelG3000HXL, TSKumHXL
(2) DSC measurement of stereocomplex crystallinity [S (%)], crystal melting temperature, etc .:
The sample was heated to 250 ° C. at 20 ° C./min under a nitrogen stream in the first cycle using DSC (TA Instrument, TA-2920), and the glass transition temperature (Tg), stereocomplex phase poly Lactic acid crystal melting temperature (Tm), stereocomplex phase polylactic acid crystal melting enthalpy (ΔHms) and homophase polylactic acid crystal melting enthalpy (ΔHmh) were measured.
Further, the crystallization start temperature (Tc *) and the crystallization temperature (Tc) were measured by rapidly cooling the measurement sample, and then measuring the second cycle under the same conditions. The stereocomplex crystallinity is a value obtained by the following formula from the stereocomplex phase and homophase polylactic acid crystal melting enthalpy obtained by the above measurement.
S = [ΔHms / (ΔHmh + ΔHms)] × 100
(However, ΔHms is the melting enthalpy of stereocomplex phase crystals, ΔHmh is the melting enthalpy of homophase polylactic acid crystals)
(3) Water resistance evaluation of hydrolysis modifier:
2 g of water was added to a system in which 1 g of sample was dissolved or partially dissolved in 50 ml of dimethyl sulfoxide, and the dissolved sample portion obtained after stirring at 120 ° C. for 5 hours under reflux was analyzed by HPLC or¹Measured by 1 H-NMR.
NMR used ECA600 manufactured by JEOL. Heavy dimethyl sulfoxide was used as the solvent, and the amount of the agent after 5 hours was determined from the amount of change in structure (integrated value).
The HPLC conditions were as follows, and the dosage was determined from the dosage area after 5 hours, with the dosage area at 0 hours being 100%.
Apparatus: Ultra high performance liquid chromatography “Nexera (registered trademark)” manufactured by Shimadzu Corporation
UV detector: Shimadzu SPD-20A 254 nm
Column: Inertsil Ph-3 3 μm 4.6 mm × 150 mm manufactured by GL Sciences (or an equivalent column can be used)
Column temperature: 40 ° C
Sample preparation: A dimethyl sulfoxide solution was diluted 500-fold with DMF and used.
Injection volume: 2 μl
Mobile phase: A: methanol, B: water
Flow rate: 1.0 ml / min (0 min: A / B = 50/50 → 10 min: A / B = 98/2 → hold until 18 min → 23 min: A / B = 50/50 → 30 min)
Water resistance was determined from the following formula (vi) using the obtained amount of the agent after 5 hours.
Water resistance (%) = [Amount after 5 h treatment / initial amount] × 100 (vi)
Other water resistance evaluation (example when B component is dissolved in tetrahydrofuran):
2 g of water was added to a system in which 1 g of a sample was dissolved in 25 ml of tetrahydrofuran and 25 ml of dimethyl sulfoxide, and the dissolved sample portion obtained after stirring at reflux at 120 ° C. for 5 hours was measured by FT-IR.
The conditions of FT-IR are as follows. Using one group (such as an alkyl chain moiety) that does not change with the treatment of the agent and the area of the carbodiimide group, the area of the carbodiimide group for 0 hour and the area of the group that does not change Taking the quotient as 100, the amount of the agent was determined from the quotient of the area of the carbodiimide group after 5 hours and the area of the group not changing.
Using the obtained amount of the agent after 5 hours, water resistance was determined from the above formula (iv).
Device: Nicolet iN10
Measurement method: Microscopic transmission method
Measurement field: 50 μm × 50 μm
Resolution: 4cm^-1
Measurement wave number: 4000-740cm^-1
Integration count: 128 times
Sample preparation: The dissolved sample was placed on a barium fluoride plate, and the solvent was volatilized.
(4) Microscopic IR measurement of the fiber cross section:
After embedding the fiber with water glue, it is cut into a cross section (fiber cross section) perpendicular to the fiber length direction with a microtome equipped with a sharp blade, and the center on the fiber cross section is determined using the apparatus described below. Microscopic IR measurement was performed on a straight line passing through. The IR absorption peak area of the carbodiimide group of the carbodiimide compound (component B) and the IR absorption peak area of the carbonyl group of the resin having the autocatalytic action (component A) were determined under the following measurement conditions, which were taken as the respective IR peak intensities.
The fiber surface was such that the IR peak intensity of the carbonyl group on the two straight lines subjected to IR measurement was 3.5 or more.
Apparatus: VERTEX HYPERION 3000 manufactured by BRUKER
Measurement method: attenuated total reflection (ATR) method
Wave number resolution: 8cm^-1
Integration count: 128 times
Effective element size: 0.5 × 0.5 μm / pixel
IR absorption peak area integration area: carbodiimide group (2280-2040 cm^-1)
Ss: carbonyl group (1910-1530cm)^-1)
The value obtained by normalizing the peak area of the obtained carbodiimide group with the peak area of the carbonyl group was defined as the abundance of the carbodiimide compound.
The fiber center is an area in a square in which the distance from the center on the fiber cross section to one side is 20% of the radius of the circumscribed circle of the fiber cross section, and PIc has the highest measured value in the above area. Value. However, when the length of one side of the square is not a multiple of the effective element size, the square of the minimum area satisfying the region is set as the fiber center.
For fiber cross-sectional shapes other than circles, the center of gravity on the fiber cross-section is regarded as the center, the straight line through which the distance between the fiber surfaces is the longest, and the straight line that passes through the center of gravity and is orthogonal to this straight line A micro IR measurement is carried out and evaluated. R_aAdopt the shortest.
From the viewpoint of leakage of the hydrolysis regulator (B component) to the outside of the fiber, suppression of process contamination during processing, and sufficient diffusion of the hydrolysis regulator (B component) into the fiber, the formula (α) is expressed. It is preferable to satisfy. Furthermore, from the viewpoint of leakage of the hydrolysis regulator (component B) to the outside of the fiber and suppression of process contamination during processing, it is preferable to satisfy the formula (γ) in the region inside the fiber surface. In consideration of sufficient diffusion of the hydrolysis regulator (component B) into the fiber, the region inside the fiber surface is preferably a region satisfying the formula (β).
(5) Reactivity evaluation with acidic group of hydrolysis modifier:
Polylactic acid "NW3001D" (MW is 150,000, carboxyl group concentration is 22.1 equivalent / ton) used for evaluation polylactic acid, and the group that reacts with the carboxyl group of the hydrolysis regulator is 33.15 equivalent / Ton, and the resin obtained by melt-kneading for 1 minute at a resin temperature of 190 ° C. and a rotation speed of 30 rpm using a lab plast mill (manufactured by Toyo Seiki Seisakusho). The carboxyl group concentration of the composition was measured, and the reactivity with acidic groups was determined from the following formula (v).
Reactivity (%) = [(carboxyl concentration of polylactic acid for evaluation−carboxyl of resin composition
Group concentration) / carboxyl concentration of polylactic acid for evaluation] × 100 (v)
(6) Evaluation of wet heat in high-temperature hot water:
300 mg of fiber and 12 ml of distilled water were charged in a sealed melting crucible (O-M Labotech, MR-28, internal volume 28 ml) preheated to 110 ° C., and sealed in advance at predetermined temperatures of 150 ° C., 170 ° C. and 190 ° C. The crucible was allowed to stand in the hot air dryer (KLO-45M, manufactured by Koyo Thermo System Co., Ltd.).
After leaving the crucible to stand in a hot air dryer, the time for the temperature inside the crucible to reach a predetermined test temperature is set as the test start time, and from this test start time for a certain period (3 hours at 150 ° C, The crucible was taken out from the hot air dryer when 2 hours were passed at 170 ° C. and 1 hour at 190 ° C.).
The crucible taken out from the hot air dryer was air-cooled for 20 minutes and then cooled to room temperature by water cooling for 10 minutes, and then the crucible was opened to collect the internal sample and water. The internal sample and water were filtered using filter paper (JIS P3801: 1995, 5 types A standard), and the residue remaining on the filter paper was dried at 60 ° C. under a vacuum of 133.3 Pa for 3 hours, and then the weight was measured. It calculated | required from the following formula (vi).
Weight (%) = [weight of residue after treatment / weight of initial fiber] × 100 (vi)
A weight of 90% or more was judged as “◯”, and a weight of less than 90% was judged as “x”.
(7) Diffusion of hydrolysis regulator (component B) out of the fiber:
If the odor due to the isocyanate compound in the spinning process is felt or the process contamination due to the diffusion of the hydrolysis modifier (component B) is observed visually, it is judged as “x” (failed), and both are recognized. If not, it was judged as “good” (passed).
(8) Acid end group amount (carboxyl group concentration):
The acidic end group amount of the composite fiber was measured as follows. A 500 mg composite fiber sample was dissolved in 15 ml of a mixed solvent of chloroform / (1,1,1,3,3,3) -hexafluoroisopropanol = 1/1 volume, and 85 ml of methanol was gradually added dropwise while stirring the solution. Then, the resin was reprecipitated, filtered through a filter paper having a pore size of 1 μm, and the powdery resin remaining on the filter paper was thoroughly washed with methanol. The resin on the filter paper is dried at room temperature using a vacuum pump for 3 hours, a 100 mg sample is taken from the dried resin powder, and stirred and dissolved in 80 ° C. purified o-cresol under a nitrogen stream for 15 minutes. It was. Bromocresol blue was added to the solution as an indicator, and titrated with an ethanol solution of 0.05 N potassium hydroxide.
Stir in purified o-cresol at 80 ° C under nitrogen flow for 15 minutes in advance, add bromocresol blue as an indicator, subtract the blank value titrated with an ethanol solution of 0.05 N potassium hydroxide, The titration value was. The sample was dissolved and titrated in o-cresol three times, and the average value was defined as the amount of acidic end groups.
The carboxyl group concentration of samples other than the composite fiber is¹Confirmed by 1 H-NMR. NMR used ECA600 made from JEOL. The solvent was deuterated chloroform and hexafluoroisopropanol, and hexylamine was added for measurement.
Hereinafter, the compounds used in this example will be described.
<Resin having autocatalytic action (component A)>
The following compounds were used as the resin (component A) having autocatalytic action.
[Production Example 1] Poly L-lactic acid resin (A1):
To 100 parts by weight of L-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%), 0.005 part by weight of octylate and 0.1 part by weight of stearyl alcohol are added, and a stirring blade is added in a nitrogen atmosphere. In a reactor with a temperature of 180 ° C. for 2 hours, phosphoric acid equivalent to 1.2 times the amount of tin octylate was added, and then the remaining lactide was removed at 13.3 Pa to form chips. A lactic acid resin (A1) was obtained.
The resulting poly L-lactic acid resin (A1) had a weight average molecular weight of 180,000, a melting point (Tmhn) of 175 ° C., and a carboxyl group concentration of 13 equivalents / ton.
[Production Example 2] Poly D-lactic acid resin (A2):
A poly D-lactic acid resin (A2) was prepared in the same manner as in Production Example 1 except that D-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%) was used instead of L-lactide in Production Example 1. )
The obtained poly-D-lactic acid resin (A2) had a weight average molecular weight of 180,000, a melting point (Tmh) of 175 ° C., and a carboxyl group concentration of 14 equivalent / ton.
[Production Example 3] Stereocomplex polylactic acid (A3):
50 parts by weight of the polylactic acid resin (A1) and the poly-D-lactic acid resin (A2) obtained in Production Examples 1 and 2 were each dried at 110 ° C. for 5 hours, and the bent type 2 having a diameter of 30 mmφ. Supplied to a screw extruder [TEX30XSST manufactured by Nippon Steel Works, Ltd.], melt extruded at a cylinder temperature of 280 ° C., a screw speed of 300 rpm, a discharge rate of 7 kg / h, and a vent vacuum of 3 kPa, and pelletized, and stereocomplex polylactic acid ( A3) was obtained.
The obtained stereocomplex polylactic acid resin (A3) has a weight average molecular weight of 135,000, a melting point (Tms) of 221 ° C., a carboxyl group concentration of 16 equivalents / ton, and a stereocomplex crystallinity (S) of 51%. there were.
[Production Example 4] Stereocomplex polylactic acid (A4):
100 parts by weight of polylactic acid resin comprising 50 parts by weight of poly L-lactic acid resin (A1) and poly D-lactic acid resin (A2) obtained in Production Examples 1 and 2 and phosphoric acid-2,2′-methylenebis (4 , 6-Di-tert-butylphenyl) sodium (“ADK STAB (registered trademark)” NA-11: manufactured by ADEKA Corporation) 0.04 part by weight was mixed with a blender and dried at 110 ° C. for 5 hours. To the bent type twin screw extruder [TEX30XSST manufactured by Nippon Steel Works, Ltd.], melt extruded at a cylinder temperature of 280 ° C., a screw rotation speed of 300 rpm, a discharge rate of 7 kg / h, and a vent pressure reduction degree of 3 kPa, and pelletized. Complex polylactic acid (A4) was obtained.
The obtained stereocomplex polylactic acid resin (A4) had a weight average molecular weight of 130,000, a melting point (Tms) of 216 ° C., a carboxyl group concentration of 16 equivalents / ton, and a stereocomplex crystallinity (S) of 100%. .
<Hydrolysis regulator (component B)>
The following additives were used as hydrolysis regulators (component B).
B1: DIPC (carbodiimide compound, manufactured by Kawaguchi Chemical Industry Co., Ltd.)
B2: “STABAXOL (registered trademark)” P (carbodiimide compound, manufactured by Rhein Chemie)
B3: “Carbodilite (Carbodilite)” LA-1 (carbodiimide compound, manufactured by Nisshinbo Chemical Co., Ltd.)
B4: “Celoxide (registered trademark)” 2021P (epoxy compound, manufactured by Daicel Corporation)
CC2: cyclic carbodiimide CC2 described in WO2010 / 071213 pamphlet, Production Example 2
The water resistance of each component B and the reactivity with acidic groups are listed in the table below.

A sample having a water resistance of 95% or more and a reactivity with an acidic group of 50% or more was judged as ◯.
B1 and B4 were evaluated for water resistance using dimethyl sulfoxide, and B2 and B3 were evaluated for other water resistance.
[Example 1]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A3) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Example 2]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B2) were kneaded by a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Example 3]
97 parts by weight of poly L-lactic acid (A1) that had been dehumidified and dried at 50 ° C. and 3 parts by weight of a hydrolysis regulator (B1) were kneaded in a twin-screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, poly D-lactic acid (A2) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 150 ° C. The evaluation results are shown in Table 2.
[Example 4]
88 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 12 parts by weight of hydrolysis modifier (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath portion, polybutylene terephthalate (Wintech Polymer Co., Ltd. “Juranex” TRE-DM2) (PBT) which was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Comparative Example 1]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. The odor due to the isocyanate compound in the process at the time of spinning was remarkable, and process contamination due to the diffusion of the hydrolysis adjusting agent (component B) was observed. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Comparative Example 2]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B3) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Comparative Example 3]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B4) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid round cross section, concentric core-sheath structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.
[Comparative Example 4]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (CC2) were kneaded with a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. The obtained fibers were subjected to wet heat evaluation in high-temperature hot water at 170 ° C. The evaluation results are shown in Table 2.

[Example 5]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A3) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid, concentric core-sheath structure with a round cross section). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 203 ° C. for 3 seconds. Odor due to isocyanate compound in the spinning process and process contamination due to visual diffusion of DIPC (component B) were not observed, so there was no diffusion of DIPC (component B) outside the fiber, and it diffused moderately within the fiber. It seems that there is.
As a result of carrying out micro IR measurement of the fiber cross section for the obtained fiber, the average value of the formula (α) was 0.42, which was acceptable. Furthermore, wet heat evaluation in high-temperature hot water at 170 ° C. was performed. The evaluation results are shown in Table 3.
[Example 6]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B2) were kneaded by a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound and process contamination due to visual diffusion of DIPC (component B) were not observed in the spinning process, so there was no diffusion of DIPC (B1) out of the fiber, and it was diffused moderately within the fiber. It seems to be. As a result of carrying out micro IR measurement of the fiber cross section for the obtained fiber, the average value of the formula (α) was 0.38, which was acceptable. Furthermore, wet heat evaluation in high-temperature hot water at 170 ° C. was performed. The evaluation results are shown in Table 3.
[Example 7]
97 parts by weight of poly L-lactic acid (A1) that had been dehumidified and dried at 50 ° C. and 3 parts by weight of a hydrolysis regulator (B1) were kneaded in a twin-screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, poly D-lactic acid (A1) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 6 seconds with a roller at 120 ° C. Odor due to isocyanate compound in spinning process and process contamination due to visual diffusion of DIPC (B1) were not observed, so there was no diffusion of DIPC (B1) to the outside of the fiber, and it diffused moderately within the fiber I think that the. As a result of carrying out micro IR measurement of the fiber cross section for the obtained fiber, the average value of the formula (α) was 0.1, which was acceptable. Furthermore, wet heat evaluation in high-temperature hot water at 150 ° C. was performed. The evaluation results are shown in Table 3.
[Comparative Example 5]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of DIPC (B1) were kneaded with a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 203 ° C. for 3 seconds. The odor due to the isocyanate compound in the spinning process was significant, and process contamination due to the diffusion of DIPC (B1) was observed. As a result of carrying out micro IR measurement of the fiber cross section for the obtained fiber, the average value of the formula (α) was 0.9, which was unacceptable. Furthermore, wet heat evaluation in high-temperature hot water at 170 ° C. was performed. The evaluation results are shown in Table 3.
[Comparative Example 6]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of DIPC (B1) were kneaded by a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 2 shows the number of holes in the die, the diameter of the discharge part, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 203 ° C. for 3 seconds. The odor due to the isocyanate compound in the spinning process was significant, and process contamination due to the diffusion of DIPC (B1) was observed. As a result of carrying out micro IR measurement of the fiber cross section for the obtained fiber, the average value of the formula (α) was 0.85, which was unacceptable. Furthermore, wet heat evaluation in high-temperature hot water at 170 ° C. was performed. The evaluation results are shown in Table 3.

[Example 8]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A3) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 203 ° C. for 3 seconds. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 9]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B2) were kneaded by a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 10]
97 parts by weight of poly L-lactic acid (A1) that had been dehumidified and dried at 50 ° C. and 3 parts by weight of a hydrolysis regulator (B1) were kneaded in a twin-screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, poly D-lactic acid (A2) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 6 seconds with a roller at 120 ° C. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and wet heat evaluation in high-temperature hot water at 150 ° C. were performed. The evaluation results are shown in Table 4.
[Example 11]
88 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 12 parts by weight of hydrolysis modifier (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath portion, polybutylene terephthalate (Wintech Polymer Co., Ltd. “Juranex” TRE-DM2) (PBT) which was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 180 ° C. for 4 seconds. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 12]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core.
Further, 99.5 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 0.5 part by weight of a hydrolysis regulator (CC2) were kneaded with a twin screw extruder to obtain a resin composition. Got. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the sheath.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Heat setting was not performed. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Comparative Example 7]
90 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed with a roller at 203 ° C. for 3 seconds. The odor due to the isocyanate compound in the process at the time of spinning was remarkable, and process contamination due to the diffusion of the hydrolysis adjusting agent (component B) was observed. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 13]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B3) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 14]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of hydrolysis regulator (B4) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A4) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Example 15]
90 parts by weight of stereocomplex polylactic acid (A4) that had been dehumidified and dried at 50 ° C. and 10 parts by weight of a hydrolysis regulator (CC2) were kneaded with a twin screw extruder to obtain a resin composition. The resin composition which had been dehumidified and dried at 50 ° C. was spun at 230 ° C. using an extruder-type spinning device. Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound in the spinning process and process contamination due to diffusion of hydrolysis modifier (component B) were not observed, so there was no diffusion of hydrolysis modifier (component B) outside the fiber, It seems to have diffused moderately. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Comparative Example 8]
78 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 22 parts by weight of hydrolysis modifier (B1) were kneaded by a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A3) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Heat setting was not performed. Odor due to an isocyanate compound in the process at the time of spinning and process contamination due to the diffusion of the hydrolysis modifier (component B) were not observed. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.
[Comparative Example 9]
60 parts by weight of stereocomplex polylactic acid (A3) that had been dehumidified and dried at 50 ° C. and 40 parts by weight of hydrolysis regulator (B1) were kneaded with a twin screw extruder to obtain a resin composition. This resin composition was dehumidified and dried at 50 ° C. to obtain a resin composition for the core. As the resin composition for the sheath, stereocomplex polylactic acid (A3) that was dehumidified and dried at 50 ° C. was used.
Spinning was performed at 230 ° C. using an extruder-type core-sheath composite spinning device (solid and round concentric structure). Table 4 shows the number of holes in the die, the diameter of the discharge section, the discharge amount, the spinning speed, and the draw ratio. Following stretching, heat setting was performed for 4 seconds with a 196 ° C. roller. Odor due to isocyanate compound in the spinning process and expansion of hydrolysis modifier (component B) by visual inspection
No contamination of the process was observed. About the obtained fiber, the measurement of the amount of acidic terminal groups and the wet heat evaluation in the high temperature hot water at 170 degreeC were performed. The evaluation results are shown in Table 4.

Claims

A method for producing a core-sheath type composite fiber composed of a core part and a sheath part,
A resin composition (C component) containing a resin (A component) having an autocatalytic action and a hydrolysis regulator (B component) is disposed in the core part, and a resin having an autocatalytic action is provided in the sheath part. A resin composition (D component) that is substantially free of hydrolysis modifier (B component) is arranged in (A ′ component), and the hydrolysis regulator (B component) in the resin composition (C component) is all A method for producing a core-sheath composite fiber, characterized in that the amount is 1 to 40 parts by weight based on the weight.
The manufacturing method of Claim 1 which satisfy | fills following formula (I).

(However, in the formula, Qc: discharge amount of the core portion, Qs: discharge amount of the sheath portion, D: diameter of the discharge port)
3. The production method according to claim 1, wherein the resin (component A) having autocatalytic action is polyester.
4. The process according to claim 1, wherein the autocatalytic resin (component A) has a main chain mainly composed of water-soluble monomer units.
The production method according to claim 4, wherein the resin (component A) having an autocatalytic action has a main chain mainly composed of lactic acid units represented by the following formula (1).
6. The production method according to claim 5, wherein the resin (component A) having an autocatalytic action includes a stereocomplex phase formed by poly L-lactic acid and poly D-lactic acid.
The production method according to any one of claims 1 to 6, wherein the hydrolysis regulator (component B) has a carbodiimide group.
The method according to claim 7, wherein the hydrolysis regulator (component B) is a carbodiimide compound represented by the following formula (2).

(Wherein R 1 to R 4 are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, X and Y may each independently represent a hydrogen atom, an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or these (It is a combination and may contain a hetero atom. Each aromatic ring may be bonded by a substituent to form a cyclic structure.)
The method according to claim 8, wherein the hydrolysis regulator (component B) is bis (2,6-diisopropylphenyl) carbodiimide.
The method according to claim 8, wherein the hydrolysis regulator (component B) is a carbodiimide compound comprising a repeating unit represented by the following formula (3).

(Wherein R 5 to R 7 are each independently an aliphatic group having 1 to 20 carbon atoms, an alicyclic group having 3 to 20 carbon atoms, an aromatic group having 5 to 15 carbon atoms, or a combination thereof, (It may contain atoms.)
11. The production according to claim 1, wherein the resin having the autocatalytic action contained in the core part (component A) and the resin having the autocatalytic action contained in the sheath part (A ′ component) are the same resin. Method.
The production method according to any one of claims 1 to 11, further comprising a step of performing a heat treatment at 60 ° C or higher after spinning.
A core-sheath type composite fiber produced by the method according to any one of claims 1 to 12.
The fiber according to claim 13, which satisfies the following formula (α) when microscopic IR measurement is performed on two orthogonal straight lines passing through the center on the cross section of the fiber.

(However, in the formula, PIs: average value of IR peak intensity ratio obtained from carbodiimide group / carbonyl group at four points on the fiber surface, PIc: highest IR peak intensity ratio obtained from carbodiimide group / carbonyl group at fiber center)
When the microscopic IR measured in the two orthogonal straight line passing through the center of the fiber cross-section, the average value of the following formula b 4 a point present on the circumference of a r a satisfying the following formula (beta) and the radius The fiber according to claim 14, which satisfies (γ).

(Wherein, r: distance from the center of the fiber cross-section on each of the microscopic IR measurement linear to the fiber surface, r a: is on each having a microscopic IR measurement linear, fiber cross-section on 0 <r a <r) to a point a existing between the center of the fiber and the fiber surface

(However, in the formula, PIb: IR peak intensity ratio obtained from carbodiimide group / carbonyl group at a certain point b existing between each point a and the fiber surface on each straight line obtained by microscopic IR measurement)
A core-sheath type composite fiber composed of a core part and a sheath part,
(I) The core is composed of a resin composition (C component) containing a resin (A component) having autocatalytic action and a hydrolysis regulator (B component), and the content of the hydrolysis regulator (B component) Is 1 to 40 parts by weight based on the total weight,
(Ii) The sheath part contains a hydrolysis regulator (B component) at a lower concentration than the C component in the resin (A ′ component) having autocatalytic action, or substantially contains the hydrolysis regulator (B component). A resin composition not contained (component D),
(Iii) The core-sheath type composite fiber according to claim 13, wherein the amount of acidic end groups of the composite fiber is 5 eq / ton or less.
The core-sheath type composite fiber according to claim 16, wherein the resin (A component) having autocatalytic activity of the core part and the resin (A 'component) having autocatalytic action of the sheath part are the same resin.