JP2017101092A - Resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin composition which keeps its weight and shape in hot water at a high temperature equal to or higher than 175°C for a fixed period of time, and then is rapidly decomposed, and to provide a molded product formed from the same.SOLUTION: A resin composition has (a) a degree of stereocomplex polylactic acid crystallization quantitatively determined by wide-angle X-ray diffraction analysis (WAXD) of a sample after hot water treatment at 175°C for 2 hours of 50% or more, and a size of stereocomplex polylactic acid crystallization of 13 nm or more, and (b) a weight of a water-insoluble matter derived from the resin composition in hot water at 175°C after 48 hours of 20% or less.SELECTED DRAWING: None

Description

  The present invention relates to a resin composition that can be suitably used for excavating oil fields.

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 resins and the water solubility of the decomposing monomer, utilization for oil field excavation technology has been studied (Patent Documents 1 to 3). In this application, it is required to quickly decompose after maintaining the weight and shape of the resin composition 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.
In addition, slow-decomposition resins such as aromatic polyesters do not decompose quickly even in high-temperature hot water (see FIG. 3), and the monomer generated by the decomposition reacts with other components in this application and precipitates in water. This is a problem (Patent Document 4).
In the past studies, the inventors have used a hydrolysis inhibitor characterized by water resistance and reactivity with acidic groups, so that the weight of the resin in hot water at a high temperature of 135 ° C. or higher for a certain period of time. It has been found that it quickly disassembles after retaining its shape.

However, the oil field in the world has a high temperature well called HP / HT field, and Halliburton on the website has an HP / HT of 10,000 psi to 15000 psi / 150 ° C. to 175 ° C. and an Extreme HP / HT of 15000 psi It is defined as 20000 psi / 175 ° C. to 200 ° C., and Ultra HP / HT is defined as 20000 psi or more / 200 ° C. or more (see Non-Patent Document 1). Therefore, a member used for excavation from the HP / HT field to the Extreme HP / HT field is required to have hot water resistance at an ultrahigh temperature of 175 ° C. or higher.
Among these excavation techniques, there is a hydraulic fracturing technique, and it has long been reported that the productivity of wells can be improved by using this technique (Non-patent Document 2). This method was formed by injecting a high-viscosity fluid into a well and applying a high pressure to form a fracture (crack) in the mining layer and filling the fracture with a sand-like substance called proppant. It is a technology that can improve oil and gas production capacity by preventing fracturing from closing again and forming a highly permeable channel (oil / gas flow paths) semi-permanently.
In order to enhance the effect of hydraulic fracturing, it is extremely important to select a high-viscosity fluid to be injected or a proppant that supports the fracture. As the proppant, sand is generally used, but it is required to have a spherical shape and particles in order to have sufficient strength to withstand the clogging pressure of the crack and to keep the permeability high. The press-fit fluid has a viscosity capable of efficiently transporting the proppant into the fracture, requires good proppant dispersibility and dispersion stability, requires easy post-treatment, and has a small environmental load.
As the press-fit fluid, a solution obtained by dissolving a polymer in water, a solution obtained by dissolving a polymer in water and crosslinking, a water-oil emulsion, or the like is used. In addition, a method of imparting proppant transport, dispersibility, and dispersion stability by causing fibers to form a network structure with the proppant by incorporating fibers with the proppant in the press-fit fluid has been reported (Non-patent Document 3). .
Such fibers have the performance essential for press-fit fluids such as proppant transport, dispersibility, and dispersion stability as described above, and after functioning in high-temperature hot water for a certain period of time, By decomposing and water-soluble, the oil and gas flow channels are expanded to improve production efficiency, and the injection fluid can be easily recovered and discarded, and more preferably no recovery or disposal is required. It has been demanded.
While inventing such a fiber, the present inventor can maintain dispersibility by incorporating the fiber with proppant in a normal environment, but can maintain proppant dispersibility in a high temperature environment similar to an actual well. I found it not. As a result of investigating this cause, proppant dispersibility is controlled by the shape and concentration of the yarn, but in high-temperature hot water, the fiber partially or entirely melts, and the shape of the fiber may be lost. We found out that the dispersion stability of proppant was lost.
As described above, the actual condition is that a resin composition and fiber that can maintain the shape for a certain period of time in 175 ° C. ultrahigh-temperature hot water and exhibit the expected performance have not yet been obtained.

JP 2009-114448 A US Pat. No. 7,267,170 US Pat. No. 7,228,904 US Pat. No. 7,275,596

“About HP / HT”, [online], Halliburton, Inc. [searched on February 25, 2014], Internet <URL: http: // www. halliburton. com / en-US / ps / solutions / high-pressure-temperature / about-hp-ht-ht. page> Ken Ihara, “History and Impact of Hydraulic Fracturing Technology”, [online], February 14, 2011, Japan Petroleum Natural Gas and Metal Mineral Resources Organization, [Search February 25, 2014], Internet <URL: http: // oilgas-info. joggec. go. jp / pdf / 4/4310 / 1102_out_k_us_fracturing_history_impact. pdf> Ken Ihara, “Current Status of Development Technology for Unconventional Natural Gas (Tight Gas Sand, Coal Bed Methane, Shale Gas)” [online], April 15, 2009, Petroleum Natural Gas and Metal Mineral Resources Organization, [Search February 25, 2014], Internet <URL: http: // oilgas-info. joggec. go. jp / pdf / 2/2789 / 0904_out_unconventional_gas_technology. pdf>

  An object of the present invention is to provide a resin composition that rapidly decomposes after maintaining its weight and shape in high-temperature water at 175 ° C. for a certain period of time, and a molded product comprising the same.

The present inventors diligently studied about a resin composition that rapidly decomposes after maintaining its weight and shape in high-temperature water at 175 ° C. for a certain period of time.
As a result, since the melting point of the resin composition in the high-temperature hot water is significantly lower than the melting point that is usually measured, the resin composition melts in the hot water even at a temperature that maintains the shape in the atmosphere. It was found that the shape and physical properties of the molded product were lost. Furthermore, it discovered that said subject could be solved by using the resin composition which reaches | attains a specific crystallinity degree and crystal size by processing a resin composition in high temperature hot water.
As a result of further investigation, by using a hydrolysis regulator having a water resistance at 120 ° C. of 95% or more and a reactivity with acidic groups at 190 ° C. of 50% or more, 175 ° C. It has been found that the acidic group concentration can be efficiently maintained low in high-temperature hot water, and the timing of rapid decomposition of the resin composition can be controlled by the amount added.

  That is, (a) stereocomplex polylactic acid (PLA) crystallinity in a wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours is 50% or more, and stereocomplex polylactic acid (PLA) A resin composition having a crystal size of 13 nm or more is used, and if necessary, a hydrolysis regulator 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 is added to the acid group. It was found that the acidic group concentration can be efficiently kept low by using it for sealing, and the timing of rapid decomposition of the resin composition can be controlled by the amount of addition, thereby completing the present invention.

That is, according to the present invention, the following inventions are provided.
1. (A) Stereocomplex polylactic acid crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours is 50% or more, and stereocomplex polylactic acid crystal size is 13 nm or more And
(B) A resin composition in which the weight of the non-aqueous component derived from the resin composition after 48 hours in 175 ° C. hot water is 20% or less.
2. It contains a resin (A component) having a self-catalytic action mainly composed of a water-soluble monomer and a hydrolysis regulator (B component), and the content of B component is 100 parts by weight in total of A component and B component. 2. The resin composition as described in 1 above, which is 0.5 to 20 parts by weight.
3. 3. The resin composition according to 2 above, wherein the component A comprises a stereocomplex phase formed by poly L-lactic acid and poly D-lactic acid.
4). 3. The resin composition as described in 2 above, wherein the component B is a carbodiimide compound.
5). 5. The resin composition according to 4 above, wherein the 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 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 (It is a combination of these and may contain a hetero atom. Each aromatic ring may be bonded by a substituent to form a cyclic structure.)
6). 6. The resin composition as described in 5 above, wherein the component B is bis (2,6-diisopropylphenyl) carbodiimide.
7). The molded article which consists of a resin composition as described in any one of said 1-6.
8). 8. The molded product according to 7 above, wherein the shape is a fiber.

The resin composition of the present invention can maintain its shape and physical properties for a certain period in hot water at a temperature of 175 ° C. or higher, and then can be quickly decomposed.
Furthermore, since it is a resin composition using a resin having an autocatalytic action mainly composed of a water-soluble monomer, it dissolves efficiently after decomposition in high-temperature hot water, and some aromatic polyesters cause problems. It is possible to significantly reduce precipitation due to reaction with other components. In addition, by using a hydrolysis regulator 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 prevention of steady decomposition, The timing of decomposition of the resin composition in hot hot water can be controlled by the amount added.
Therefore, the resin composition of the present invention exhibits a desired performance in the oil field excavation technique, and is suitably used as a fiber that imparts transportability, dispersibility, and dispersion stability of a molded product, particularly proppant, particularly in hydraulic fracturing applications. be able to.

When the resin composition is used in high-temperature hot water at 175 ° C., it is an image diagram that quickly decomposes after maintaining the weight and shape of the resin for a certain period of time, with the behavior achieved in the resin composition of the present invention. is there. When a resin composition is used in high-temperature hot water at 175 ° C., it is an image diagram in which decomposition rapidly proceeds from the beginning, and is a behavior in a general aliphatic polyester. When a resin composition is used in high-temperature hot water at 175 ° C., it is an image diagram in which decomposition rapidly proceeds from the beginning, and is a behavior in a general aromatic polyester. When the resin composition is used in hot water at a temperature of 175 ° C., the molecular weight (m) and the amount of acidic groups (m) necessary to achieve the behavior of the weight (w) change of the resin composition as shown in FIG. It is an image figure showing the change of g), Comprising: It is the behavior achieved in the resin composition of this invention.

Hereinafter, the present invention will be described in detail.
<Resin having autocatalytic action mainly composed of water-soluble monomer (component A)>
In the present invention, the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer is a resin in which a monomer produced by decomposition exhibits water solubility, and an acidic group produced by the decomposition has an autocatalytic action. Or at least one part of the terminal of the resin is sealed with B component.
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 ratio 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 acids 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, 2-hydroxyisobutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxypivalic acid, hydroxybenzoic acid, p-hydroxybenzoic acid, Examples include 6-hydroxy-2-naphthoic acid and ester-forming derivatives thereof. 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.
Polymers mainly composed of aliphatic hydroxycarboxylic acids include polycondensates such as glycolic acid, lactic acid, hydroxypropionic acid, hydroxybutyric acid, 2-hydroxyisobutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and hydroxypivalic acid. Or a copolymer etc. can be illustrated. Among them, polyglycolic acid, polylactic acid, poly-3-hydroxycarboxylic butyric acid, poly-4-polyhydroxybutyric acid, poly-2-hydroxyisobutyric acid, polyhydroxypivalic acid, poly-3-hydroxyhexanoic acid or polycaprolactone, and copolymers thereof, etc. Is 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, Examples include 6-hexanediol, decamethylene glycol, cyclohexanedimethanol, cyclohexanediol, and dimer diol. 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 polycondensates (primalloy) of cyclohexanedicarboxylic acid and cyclohexanedimethanol, 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 this 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 polylactic acid is preferably in the range of 50,000 to 500,000, more preferably 80,000 to 350,000, and still more preferably 120,000 to 250,000 in order to achieve both the mechanical properties and the moldability of the molded product. The weight average molecular weight is a value measured by gel permeation chromatography (GPC) and converted to standard polystyrene.

When the polylactic acid (component A) is poly D-lactic acid or poly L-lactic acid and is a homophase polylactic acid, a crystal melting peak (Tmh) between 150 and 190 ° C. is measured by differential scanning calorimetry (DSC) measurement. ) And the crystal melting heat (ΔHmsc) is preferably 10 J / g or more. Heat resistance can be improved by satisfying the range of the crystal melting point and the crystal melting heat.
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 (i) of 90 to 100%.
S = [ΔHms / (ΔHmh + ΔHms)] × 100 (i)
(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 preferably at least 5%, more preferably 5-60%, even more preferably 7-60%, particularly preferably 10-60%. is there.
The crystalline melting point of stereocomplex polylactic acid is preferably 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).

The resin composition of the present invention has (a) a stereocomplex PLA crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours, and a stereocomplex The PLA crystal size is 13 nm or more.
In order to satisfy this condition, in stereocomplex polylactic acid, the crystal melting point before hydrothermal treatment is preferably 200 ° C. or higher, and more preferably 210 ° C. or higher. When the crystal melting point before the hydrothermal treatment is less than 200 ° C., the stereocomplex crystal phase is not sufficiently grown during the hydrothermal treatment, and it is highly possible that the object of the present application cannot be achieved. In order to control the crystalline melting point of stereocomplex polylactic acid within an appropriate range, the isotactic number average chain length of polylactic acid analyzed by ¹³ C-NMR is preferably 12 to 200, more preferably 20 to 150, and 25 to 25. 120 is more preferable, and 50 to 100 is most preferable. A stereocomplex polylactic acid having a preferred isotactic number average chain length is a phosphate metal salt, carboxylate metal salt, or sulfonate metal salt that promotes transesterification when melt-kneading poly-D-lactic acid and poly-L-lactic acid. It can be obtained by melt-kneading without adding a catalyst such as the above, or by adding the catalyst for promoting transesterification and melt-kneading at less than 280 ° C. When the above catalyst is added and melt-kneaded at 280 ° C or higher, the transesterification proceeds excessively. As a result, the isotactic number average chain length becomes too small, so that the stereocomplex crystal phase grows sufficiently during hydrothermal treatment. Therefore, there is a high possibility that the object of the present application cannot be achieved.

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 120,000 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 the catalyst used is 0.42 × 10 ^{−4 to} 100 × 10 ⁻⁴ (mole) per 1 kg of lactide, and 1.68 × 10 ^{−4 in} consideration of reactivity, color tone and stability of the resulting polylactides. To 42.1 × 10 ⁻⁴ (mol), particularly preferably 2.53 × 10 ^{−4 to} 16.8 × 10 ⁻⁴ (mol).

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.
Further, orthophosphoric acid represented by the formula xH ₂ O · yP ₂ O ₅ and x / y = 3 may be mentioned. 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 can be mentioned. 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.

In view of the catalyst deactivation ability, orthophosphoric acid represented by the formula xH ₂ O · yP ₂ O ₅ and 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-region 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 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. By having a lactide content in such a range, the polylactic acid component improves the stability of the resin during the melt molding of the molded product of the present invention, and the advantage that the molded product can be efficiently manufactured and the heat and humidity resistance of the molded product. , Low gas can be improved.
The 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 190 to 300 ° C, more preferably 200 to 290 ° C, and still more preferably 210 to 280 ° C, from the viewpoint of improving the stability of polylactic acid when melted and the degree of stereocomplex crystallinity.
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 stirrer, “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. 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 in which a specific additive is blended is preferably applied in order to stably and highly promote the formation of stereocomplex polylactic acid crystals within the scope not 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.
The resin composition of the present invention may be used alone as long as the object is achieved, and the resin composition consisting of a resin (component A) having an autocatalytic action mainly composed of one water-soluble monomer. Also, it can be used in combination with two or more resin compositions comprising different A components.

<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 (ii) 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 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 (ii)
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). About the resin composition which measured the carboxyl group density | concentration, it is a value given by following formula (iii).
Reactivity (%) = [(carboxyl group concentration of polylactic acid for evaluation−carboxyl group concentration of resin composition) / carboxyl group concentration of polylactic acid for evaluation] × 100 (iii)

The polylactic acid for evaluation 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 suitably 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., About the resin composition obtained by melt-kneading for 1 minute at the rotation speed of 30 rpm, the value of reactivity can be calculated | required by measuring a carboxyl group density | concentration.
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 (I) and (II).
RN = C = NR ′ (I)
Wherein R and R ′ 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 an atom. R and R ′ may be bonded to form a cyclic structure, or two or more cyclic structures may be formed by a spiro structure or the like)

(In the formula, each R ″ is 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 a heteroatom. (N is an integer from 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 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 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 combinations may contain hetero atoms, and each aromatic ring may be bonded by a substituent to form a cyclic structure, and two or more cyclic structures may be formed by a spiro structure or the like. Also good)

(In the formula, 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 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>
In order to exhibit the performance desired as a molded product, it is important to control the resin composition of the present invention so that it quickly decomposes after maintaining its weight and shape in high-temperature hot water at 175 ° C. for a certain period of time. .
The certain period is determined depending on the application, but is preferably any one of 2 hours to 12 hours. Further, from the viewpoint of exhibiting desired performance, any one of 1 hour to 6 hours is more preferable, and any one of 30 minutes to 2 hours is more preferable.
The weight of the resin composition is evaluated by the weight of the water-insoluble content after the hot water treatment compared with the weight of the resin composition before the hot water treatment. The weight of the non-water-soluble content after treatment with hot water at 175 ° C. for 2 hours is preferably 50% or more, more preferably 70% or more, and more preferably 90% or more from the viewpoint of exhibiting desired performance in hot water. preferable.
Rapid decomposition means a state in which hydrolysis of component A is promoted by autocatalysis, and the concentration of acidic groups increases exponentially. On the contrary, while the acidic group concentration is kept lower than the B component, the decomposition of the A component becomes gradual. Therefore, while the weight and shape of the resin composition are maintained, the concentration of acidic groups derived from the resin composition is preferably 30 equivalents / ton or less.
When the amount is more than 30 equivalents / ton, hydrolysis of the A component is promoted by autocatalysis, and the effect of the B component is not sufficiently exhibited. Since the lower the concentration of the acidic group, the more the change in the weight and shape of the resin composition can be suppressed. From the viewpoint of exhibiting the desired performance, the resin composition is maintained while the weight and shape of the resin are maintained. The concentration of the derived acidic group is more preferably 20 equivalent / ton or less, further preferably 10 equivalent / ton or less, and particularly preferably 3 equivalent / ton or less.
Here, the concentration of the acidic group derived from the resin composition is, for example, prepared in the same manner as in the evaluation used for determining the volume change in the weight and shape of the resin described above, and the obtained resin composition It can be determined by measuring the product by ¹ H-NMR.

In the resin composition of the present invention, component B may be added from the viewpoint of controlling the decomposition rate. The addition amount of B component is 0.5-20 weight part with respect to 100 weight part in total of A component and B component. When the amount is less than 0.5 parts by weight, a sufficient acidic group sealing effect may not be exhibited in high-temperature hot water at 175 ° C. On the other hand, when the amount is more than 30 parts by weight, there are cases where the B component bleeds out from the resin composition, the moldability deteriorates, and the characteristics of the substrate are denatured. From this viewpoint, the content of the B component is preferably 0.5 to 30 parts by weight, more preferably 1 to 20 parts by weight, and 2 to 15 parts by weight with respect to a total of 100 parts by weight of the A component and the B component. Further preferred is 3 to 10 parts by weight.
The resin composition of the present invention is (b) non-derived from a resin composition after 48 hours in hot water at 175 ° C. The weight of the water component is 20% or less, preferably 10% or less, and more preferably 5% or less.

<Method for producing resin composition>
The resin composition of the present invention can be produced by melt-kneading a resin (A component) having an autocatalytic action mainly composed of a water-soluble monomer and a hydrolysis regulator (B component).
In addition, when polylactic acid is adopted as a resin (A component) having a self-catalytic action mainly composed of a water-soluble monomer, the poly (A component) of the resin having a self-catalytic action mainly comprising a water-soluble monomer (A component). L-lactic acid, poly-D-lactic acid, and a hydrolysis regulator (component B) are mixed to form stereocomplex polylactic acid, and the resin composition of the present invention can be produced. The resin composition of the present invention can also be produced by mixing poly L-lactic acid and poly D-lactic acid to form a stereocomplex polylactic acid and then mixing a hydrolysis regulator (component B). .
The method of adding and mixing the hydrolysis regulator (component B) to the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer is not particularly limited. Method of adding as a master batch of resin (component A) having autocatalytic action mainly composed of water-soluble monomer to be applied, or water soluble in a liquid in which a hydrolysis modifier (component B) is dissolved, dispersed or melted For example, a method may be employed in which a solid of a resin (A component) having an autocatalytic action mainly composed of a monomer is brought into contact with a hydrolysis regulator (B component).

  When adding a solution, a melt or a masterbatch of a resin (component A) having autocatalytic activity mainly composed of a water-soluble monomer to be applied, 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 hydrolysis regulator (B component) which have autocatalytic action which has a water-soluble monomer as a main component 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 the ketone solvent 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.
In the present invention, 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 an emulsion liquid of a hydrolysis regulator (component B) into contact with a resin (A component) having a solid water-soluble monomer as a main component and having an autocatalytic action can be used. As a method of contact, a method of immersing a resin (A component) having a water-soluble monomer as a main component and having an autocatalytic action, or a method of applying a resin having a self-catalytic action (a component A) having a water-soluble monomer as a main component. The method of performing, the method of spraying, etc. can be taken suitably.

The acidic group sealing reaction of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer by the hydrolysis regulator (component B) is possible at a temperature of room temperature (25 ° C.) to about 300 ° C. However, it is more accelerated in the range of 50 to 280 ° C., more preferably 100 to 280 ° C. from the viewpoint of reaction efficiency. Resin having self-catalytic action mainly composed of a water-soluble monomer (component A) is more likely to react at the melting temperature, but suppresses volatilization and decomposition of the hydrolysis regulator (component B). Therefore, the reaction is preferably performed at a temperature lower than 300 ° C. Also, it is effective to apply a solvent in order to lower the melting temperature of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer and increase 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 types of hydrolysis regulators (component B) may be used in combination. For example, an initial acidic group of a resin (component A) having a self-catalytic action mainly composed of a water-soluble monomer. Separately used hydrolysis control agent (B component) that performs the sealing reaction of and hydrolysis control agent (B component) that performs the sealing reaction of acidic groups generated in hot water at a temperature higher than 135 ° C. Also good.
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 modifier (component B). It is.

The resin composition of the present invention can be used by adding all 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 mold release agent, an antistatic agent, a plasticizer, an impact resistance improver, a terminal blocking 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 of the present invention 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-tert-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 and the like can be mentioned.

  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-no Ruphenyl) 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 Dimethylbenzyl) 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, 2-ethylhexyl-cyano-3,3′-diphenyl acrylate, and the like.

  Examples of hindered amine compounds include 4-acetoxy-2,2,6,6-tetramethylpiperidine, 4-stearoyloxy-2,2,6,6-tetramethylpiperidine, -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 1,2,2,6,6-pentamethyl-4-piperidinol and β, β, β ', β'-tetra Chill 3,9 [2,4,8,10-tetra oxa spiro (5,5) undecane] condensates of dimethanol, and the like.

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 mainly composed of a water-soluble monomer. is there.

<Crystallization accelerator>
The resin composition of the present invention 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 used in the present invention, those generally used as crystallization nucleating agents for crystalline resins can be used, and both inorganic crystallization nucleating agents and organic crystallization nucleating agents are used. be able to.
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 the effect thereof, and are in a highly dispersed state with 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 30 parts by weight, more preferably 0.05 to 20 parts per 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. Parts by weight.

<Filler>
The resin composition of the present invention 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.

In the present invention, the blending amount of the organic filler is not particularly limited, but from the viewpoint of moldability and heat resistance, per 100 parts by weight of resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. The amount is preferably 1 to 300 parts by weight, more preferably 5 to 200 parts by weight, still more preferably 10 to 150 parts by weight, and particularly preferably 15 to 100 parts by weight.
If the blending amount of the organic filler is less than 1 part by weight, the effect of improving the moldability of the composition is small, and if it exceeds 300 parts by weight, uniform dispersion of the filler becomes difficult, or other than moldability and heat resistance In addition, the strength and appearance of the material may decrease, which is not preferable.

The composition of the present invention preferably contains an inorganic filler. By combining the inorganic filler, a 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 blending amount of the inorganic filler is preferably 0.1 to 200 parts by weight, more preferably 0.5 to 100 parts by weight per 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. Parts, more preferably 1-50 parts by weight, particularly preferably 1-30 parts by weight, most preferably 1-20 parts by weight.

<Release agent>
The resin composition of the present invention can contain a release agent. As the mold release agent used in the present invention, 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, pentaerythritol 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 partial saponified ester, polyethylene wax, acid value polyethylene wax, sorbitan fatty acid ester, erucic acid amide, and ethylene bisstearic acid amide are preferred, and particularly, montanic acid partial saponified ester and ethylene bisstearic acid amide are preferred. 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, more preferably 0.03 to 2 parts per 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. Parts by weight.

<Antistatic agent>
The resin composition of the present invention can contain an antistatic agent. Examples of the antistatic agent include (β-lauramidopropionyl) trimethylammonium sulfate, quaternary ammonium salts such as 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 based on 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. Parts by weight.

<Plasticizer>
The resin composition of the present invention 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 30 parts by weight, more preferably 0.05 to 20 parts by weight per 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. More preferably, it is 0.1 to 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.

<Impact resistance improver>
The resin composition of the present invention 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 1 to 30 parts by weight, more preferably 5 to 20 parts by weight with respect to 100 parts by weight of the resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer. More preferably, it is 10 to 20 parts by weight.

<Others>
The resin composition of the present invention 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 of the present invention may contain a flame retardant such as bromine, phosphorus, silicone, antimony compound and the like within a range not departing from the spirit of the present invention.
In addition, colorants including 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.

<Molded product>
The molded article made of the resin composition of the present invention preferably has “good” shape retention after a hot water test at 175 ° C. for 2 hours.
When the stereocomplex PLA crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of the sample after hydrothermal treatment at 175 ° C. for 2 hours is less than 50%, or the stereocomplex PLA crystal size is less than 13 nm In some cases, part or all of the sample melts and flows during the test, and the shape cannot be maintained. Specifically, the initial shape is not particularly concerned, but when a hot water test at 175 ° C. is performed using a plurality of test pieces, preferably 5 or more, a lump or partly melted after the test. The case where it is in a worn state is defined as “defective”, and the state in which each test piece is easily dispersed is defined as “good”.

In forming the resin composition of the present invention into a molded product, it can be molded by injection molding, extrusion molding, vacuum, pressure molding, blow molding, or the like. Examples of the molded article include pellets, fibers, fabrics, fiber structures, films, sheets, and sheet nonwoven fabrics.
The pellet made of the resin composition of the present invention is not limited in its melt molding method, and those produced by a known pellet production method can be suitably used.
That is, the resin composition placed in the form of a strand or plate is cut in the air or in water after the resin is completely solidified or not completely solidified and still in a molten state. These methods are conventionally known, but any of them can be suitably applied in the present invention.
In the injection molding, the molding conditions may be appropriately set depending on the type of resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer, but at the time of injection molding of the polylactic acid composition, the molded product is crystallized. From the viewpoint of increasing the molding cycle, for example, the mold temperature is preferably 30 ° C. or higher, more preferably 60 ° C. or higher, and further preferably 70 ° C. or higher. However, in order to prevent deformation of the molded product, the mold temperature is preferably 140 ° C. or lower, more preferably 120 ° C. or lower, and further preferably 110 ° C. or lower.

<Fiber>
The fiber of the present invention has a stereocomplex PLA crystallinity of 50% or more and a stereocomplex PLA crystal size in a wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours. As long as it is possible to obtain a fiber that is 13 nm or more and (b) the weight of the non-water-soluble component derived from the fiber after 48 hours in 175 ° C. hot water is 20% or less, its production method is limited. Any known method can be applied.
For example, when melt spinning a resin (A component) having an autocatalytic action mainly composed of a water-soluble monomer, the A component is melted by an extruder type or pressure melter type melt extruder, and then measured by a gear pump. After being filtered in the pack, it is discharged as a monofilament, a multifilament or the like from a nozzle provided in the base.
The resin composition may be obtained by melting and kneading pellets obtained by melt kneading in advance with a melt extruder, or by supplying the component A and component B to the melt extruder and melt kneading. At this time, the component B may be in a solid state, a liquid state, or a master batch. Further, when the component A is stereocomplex polylactic acid, the raw materials, poly L-lactic acid, poly D-lactic acid, and a transesterification catalyst may be supplied to a melt extruder and melt kneaded.

The shape of the die and the number of the die are not particularly limited, and any of circular, irregular, solid, hollow, conjugate, etc. can be adopted. Particularly in the case of a conjugate, it is preferable that at least one layer contains a hydrolysis regulator (component B). The discharged yarn is immediately cooled and solidified, then converged, applied with oil, and wound. When cooling, air at 10 to 40 ° C. can be blown to the spun yarn at a position of 5 to 200 mm below the spinneret to promote cooling and solidification. At this time, if the uniformity of air blowing is poor, the linearity after the thermal test is lowered. Therefore, it is preferable to adjust the uniformity according to the purpose. For example, when sent from one side, the linearity after the thermal test becomes too low, and the sedimentation suppression ability may be reduced.
The winding speed is not particularly limited, but a range of 100 to 10,000 m / min is preferable. From the viewpoint of suppressing heat shrinkage, the winding speed is preferably 5,000 m / min or less because of the influence of draft orientation during spinning. However, even at a high speed spinning of 5,000 m / min or more, thermal shrinkage can be suppressed by relaxation and crystallization treatment in post-processing, and this is not restrictive. High-speed spinning at 5000 m / min or higher enables highly oriented crystallization, and can also increase the melting point and crystallinity.
The wound undrawn yarn can be used as it is, but can 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. Any known method can be used for the heat treatment. For example, a method of heating the fiber in a gas or liquid medium can be applied. Examples of the heat source for direct contact include steam and a hot roller. Examples of the medium include water, an organic solvent, and a compound that becomes a melt at a heat treatment temperature. The melt may be a low molecular compound or a high molecular compound. The heat treatment may be performed once or twice or more, and some methods may be combined. When the heat treatment is performed twice or more, the heat treatment temperature may be changed stepwise. As a method for heating the gas and the liquid, a hot air oven, a steam oven, an electric heater, an infrared heater, microwave irradiation, or the like can be appropriately selected. Furthermore, a method of contacting with a solvent can be selected as a method of crystallization without heating.
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 drawing may be one-step drawing or multi-step drawing of two or more steps, and the draw ratio is preferably 4 times or less, more preferably 3 times or less from the viewpoint of producing a yarn having low heat shrinkage at 175 ° C. Preferably 1.05 to 2 times is selected. If the draw ratio is too high, the heat shrinkage at 175 ° C. increases, which is not preferable.
As a preheating method for stretching, in addition to the temperature rise of the roll, a flat or pin-like contact heater, a non-contact hot plate, a heat medium bath, and the like can be used, and a commonly used method may be used.
The stretching temperature is, for example, 40 to 130 ° C, preferably 50 to 120 ° C, particularly preferably 60 to 110 ° C.

  It is preferable that a heat treatment is performed following the stretching. As the heat treatment, generally known methods can be applied. For example, a method in which a heat source is brought into direct contact with the fiber, a method in which the fiber is heated in a gas or liquid medium, and the like can be applied. Examples of the heat source for direct contact include steam and a hot roller. Examples of the medium include water, an organic solvent, and a compound that becomes a melt at a heat treatment temperature. The melt may be a low molecular compound or a high molecular compound. The heat treatment may be performed once or twice or more, and some methods may be combined. When the heat treatment is performed twice or more, the heat treatment temperature may be changed stepwise. As a method for heating the gas and the liquid, a hot air oven, a steam oven, an electric heater, an infrared heater, microwave irradiation, or the like can be appropriately selected.

The heat treatment temperature is, for example, 100 to 225 ° C, preferably 130 to 220 ° C, more preferably 160 to 215 ° C, particularly preferably 180 to 210 ° C, and most preferably 195 to 200 ° C. If it is too low, the crystallinity will not increase, and the fiber shape retention in hot water may deteriorate. In addition, since the melting point of the fiber is significantly lower than the melting point measured in the nitrogen atmosphere as described above in the high temperature hot water, the temperature is very close to the temperature at which the fiber melts in the high temperature hot water of 175 ° C. Heat treatment is preferably performed at a high temperature as close to the melting point as possible from the viewpoint of fiber shape retention. However, if it is too high, there are cases where the fiber melts and breaks or fuses, and the hydrolysis regulator (component B) volatilizes.
The heat treatment time is not particularly specified and depends on the heat treatment method and the heat treatment temperature. For example, in the case of contact-type roll heating, 0.1 to 20 seconds is preferable, more preferably 1 to 10 seconds, and particularly preferably 2 to 2 seconds. 8 seconds, most preferably 3-6 seconds.

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.
The obtained fiber can be appropriately heat-treated from the viewpoint of improving hot water resistance and reducing thermal shrinkage in 175 ° C. hot water. As the heat treatment, generally known methods can be applied. For example, a method in which a heat source is brought into direct contact with the fiber, a method in which the fiber is heated in a gas or liquid medium, and the like can be applied. Examples of the heat source for direct contact include steam and a hot roller. Examples of the medium include water, an organic solvent, and a compound that becomes a melt at a heat treatment temperature. The melt may be a low molecular compound or a high molecular compound. The heat treatment may be performed once or twice or more, and some methods may be combined. When the heat treatment is performed twice or more, the heat treatment temperature may be changed stepwise. As a method for heating the gas and the liquid, a hot air oven, a steam oven, an electric heater, an infrared heater, microwave irradiation, or the like can be appropriately selected.

Moreover, from the viewpoint of controlling the hydrolysis of the fiber in high-temperature hot water, a heat treatment method that suppresses a decrease in the hydrolysis regulator (component B) in the molded product can be suitably applied. For example, a method in which heat treatment is performed in a state where fibers are sealed in a sealed container, a method in which heat treatment is performed in a medium in which the hydrolysis regulator (component B) does not elute, and a medium in which the hydrolysis modifier (component B) is saturated. The method of heat-treating with, the method of heat-treating in a state where the fiber is physically coated, the method of combining them, etc. can be suitably applied.
The ultimate heat treatment temperature may be appropriately set depending on the melting point of the fiber, but is preferably 180 to 240 ° C., from the viewpoint of efficiently improving hot water resistance and reducing thermal shrinkage in 175 ° C. hot water. Is selected from the range of 190 to 235 ° C, more preferably 200 to 230 ° C, and particularly preferably 210 to 220 ° C.
The heat treatment time is not particularly specified, and depends on the heat treatment method and the heat treatment temperature, but is selected from 0.1 seconds to 120 minutes, preferably from 0.1 seconds to 110 minutes, more preferably from 0.1 seconds to 100 minutes. .

The fiber of the present invention can be suitably used for hydraulic crushing applications. By including the fiber together with the proppant in the press-fitting fluid used for hydraulic fracturing, the fiber forms a network structure with the proppant, thereby imparting proppant transport, dispersibility, and dispersion stability. The proppant dispersibility at this time is controlled by the shape and density of the yarn. In order to impart proppant transport, dispersibility, and dispersion stability, the fibers are preferably short fibers. When manufacturing a short fiber, in addition to the drawing process with a long fiber, the process of cutting with a rotary cutter etc. to the predetermined fiber length according to a use is added. Before and after cutting, crimping, drying, and surface treatment with an oil agent can be performed as appropriate, and these steps may be continuous or offline.
Also, when the fiber is transported, it is bulky in the state of being cut into short fibers, which increases the transportation cost. In some cases, it may be cut appropriately.
The length of the fiber is appropriately optimized depending on the viscosity of the fluid used and proppant, but is preferably in the range of 3 to 20 mm, more preferably 5 to 10 mm, and even more preferably 5 to 7 mm. If the fiber is long, when propand and fiber are mixed and dispersed in the fluid, the yarns may be entangled with each other and the dispersibility may be deteriorated. Dispersibility and dispersion stability are reduced.

The fiber thickness is preferably 3 μm or more and 50 μm or less, more preferably 5 μm or more and 40 μm or less, still more preferably 6 μm or more and 30 μm or less, and particularly preferably 7 μm or more and 20 μm or less. If the fiber is too thick, the proppant transport, dispersibility, and dispersion stability may be reduced. If the fiber is too thin, the proppant transport and dispersibility may be deteriorated due to a decrease in productivity and insufficient fiber strength. The shape of the fiber and the concentration added to the fluid are appropriately adjusted depending on the application and the composition of the press-fit fluid.
If further crimping is required, a step of applying crimping with an indentation crimper or the like is added between the constant-length heat treatment and 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.
Moreover, the polylactic acid fiber which has high stereo complex crystallinity (S) and low heat-shrinkability can also be obtained by heat-setting at 170 degreeC-220 degreeC under tension after extending | stretching. This heat setting treatment can also be performed for the purpose of “heat treatment” performed from the viewpoint of improving hot water resistance and reducing thermal shrinkage as described above.

From the viewpoint of hot water resistance, heat shrinkage, and shape retention, the range of crystallinity measured by X-ray is preferably at least 5% or more, more preferably 20% or more, and further preferably 30%. Above, particularly preferably 40% or more.
The fiber of the present invention preferably has a heat shrinkage rate of 30% or less after 2 hours in 175 ° C. hot water from the viewpoint of transporting proppant, dispersibility, and imparting dispersion stability. More preferably, it is preferably 20% or less, and particularly preferably 10% or less.
The fibers of the present invention preferably have a linearity of 50% or more after 2 hours in 175 ° C. hot water from the viewpoint of proppant transport, dispersibility, and imparting dispersion stability. More preferably, it is preferably 60% or more, and particularly preferably 70% or more.

<Crystal structure after hydrothermal treatment>
Since the resin composition of the present invention achieves a desired function in high-temperature hot water, (a) a stereocomplex PLA in wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours The crystallinity is 50% or more, and the stereocomplex PLA crystal size is 13 nm or more. When this condition is not satisfied, a part or all of the resin constituting the resin composition is melted in hot water. As a result, the shape and physical properties of the molded product are lost, and the desired performance cannot be exhibited. For example, in the case of fibers for inhibiting proppant sedimentation, fusion and remarkably shrinkage of the fibers occur, and the proppant dispersion stability is significantly lowered.
From the viewpoint of preventing partial melting in hot water, (a) the stereocomplex PLA crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of the sample after hydrothermal treatment at 175 ° C. for 2 hours is 50 % Or more, preferably 55% or more, and more preferably 60% or more.
From the viewpoint of preventing partial melting in hotter hot water, (a) a stereocomplex PLA crystal quantified by wide-angle X-ray diffraction analysis (WAXD) of the sample after hydrothermal treatment at 175 ° C. for 2 hours The size is 13 nm or more, preferably 13.3 nm or more, and more preferably 13.8 nm or more.

In the resin composition of the present invention, wide-angle X-ray diffraction analysis of a resin composition that has been treated in high-temperature hot water for the purpose of exhibiting performance in high-temperature hot water assumed in an actual high-temperature well ( It is important that the result of the crystal structure analysis by WAXD) satisfies the above-mentioned conditions, and the result of the crystal structure analysis by wide-angle X-ray diffraction analysis (WAXD) of the resin composition before the treatment in high-temperature hot water satisfies the above-mentioned conditions. It is not essential to meet.
For example, in a stereocomplex polylactic acid resin composition to which an appropriate hydrolysis adjusting agent has been added, the injection molded product that has been rapidly cooled after being melted has insufficient crystallization, so that the stereocomplex PLA crystallinity is less than 50% and The complex PLA crystal size may be less than 13 nm. Also in this resin composition, in the actual use situation in the high temperature well, as a result of the progress of crystal growth and high melting point in the process of transporting the resin composition from the normal temperature ground to the high temperature ground, In some cases, the shape and physical properties can be maintained even in high-temperature hot water and desired performance can be exhibited. In such a case, the crystal structure analysis result by wide-angle X-ray diffraction analysis (WAXD) of the resin composition that has been treated in high-temperature hot water satisfies the above-described conditions.

On the other hand, even when the crystal structure analysis result by wide-angle X-ray diffraction analysis (WAXD) of the resin composition before treatment in high-temperature hot water satisfies the above-mentioned conditions, the decomposition and molecular structure by treatment in high-temperature hot water In such a case, the stereocomplex PLA crystallinity and crystal size are reduced, and the shape and physical properties in high-temperature hot water are not maintained, and the desired performance cannot be exhibited. In such a case, the results of crystal structure analysis by wide-angle X-ray diffraction analysis (WAXD) of the resin composition that has been treated in high-temperature hot water have the above-mentioned conditions because the stereocomplex PLA crystallinity and crystal size decrease. Do not meet.
Thus, by analyzing the crystal structure of the resin composition that has been treated in high-temperature hot water by wide-angle X-ray diffraction analysis (WAXD), the essential performance of the resin composition in a high-temperature well is accurately estimated. can do. However, the resin composition satisfying the above-mentioned crystal structure analysis result by wide-angle X-ray diffraction analysis (WAXD) both before and after treatment in high-temperature hot water always has shape and physical properties in an actual well. Is more preferable because it is more likely to be retained.
From such a viewpoint, in the treatment in high-temperature hot water at 175 ° C., in view of the heating rate in the actual hydraulic crushing method, the resin composition is changed from room temperature to 175 ° C. over an appropriate time from 15 minutes to 100 minutes. It is necessary to raise the temperature. Furthermore, from the viewpoint of appropriately evaluating the decomposability in hot water, a method of lowering the temperature to room temperature within 30 minutes after holding at a predetermined temperature in hot water can be used to prevent unnecessary decomposition of the resin composition. It is preferable to perform a test.

In the present invention, the crystal structure analysis by wide-angle X-ray diffraction analysis (WAXD) of the sample after the hydrothermal treatment is performed by the following method. An X-ray diffraction pattern is recorded on an imaging plate under the following conditions by a transmission method using a wide-angle X-ray diffractometer (for example, an Ultrax 18 type X-ray diffractometer manufactured by Rigaku).
X-ray source: Cu-Kα ray (confocal mirror)
Output: 45kV x 60mA
Slit: 1st: 1mmΦ, 2nd: 0.8mmΦ
Camera length: 120mm
Integration time: 10 minutes Sample: Weight 35mg
In the obtained X-ray diffraction pattern, the total scattering intensity Itotal is obtained over the azimuth angle, and each diffraction peak derived from the stereocomplex polylactic acid crystal appearing in the vicinity of 2θ = 12.0 °, 20.7 °, 24.0 °. The total sum ΣISCi of the integrated intensities is obtained. The stereocomplex polylactic acid crystallinity is determined from these values according to the following formula (iv).
Stereocomplex polylactic acid crystallinity (%) = ΣISCi / Itotal × 100 (iv)
For crystallite size D, stereocomplex polylactic acid crystallites according to Scherrer formula (v) below using Bragg angles and half-value widths of diffraction peaks derived from stereocomplex polylactic acid crystals appearing around 2θ = 12.0 ° The size Dsc is obtained.
Dsc = K · λ / βcos θ (nm) (v)
Dsc: Stereo complex polylactic acid crystallite size K: Scherrer constant λ: X-ray wavelength (Å)
β: Half width (broadening of diffraction lines)
θ: Bragg angle of diffraction line Note that ΣISCi is calculated by subtracting diffuse scattering due to background or amorphous from the total scattering intensity.

Hereinafter, the present invention will be further described by examples. 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) Carboxyl group concentration:
The carboxyl group concentration of the resin composition of the example was confirmed by ¹ H-NMR. NMR used ECA600 made from JEOL. The solvent was deuterated chloroform and hexafluoroisopropanol, and hexylamine was added for measurement.
For the other samples, the sample was dissolved in purified o-cresol, dissolved in a nitrogen stream, and titrated with an ethanol solution of 0.05 N potassium hydroxide using bromocresol blue as an indicator.

(3) Crystal structure analysis by wide-angle X-ray diffraction analysis (WAXD):
An X-ray diffraction pattern was recorded on an imaging plate under the following conditions by the transmission method using a Rigaku ultra 18 type X-ray diffractometer.
X-ray source: Cu-Kα ray (confocal mirror)
Output: 45kV x 60mA
Slit: 1st: 1mmΦ, 2nd: 0.8mmΦ
Camera length: 120mm
Integration time: 10 minutes Sample: Weight 35mg
In the obtained X-ray diffraction pattern, the total scattering intensity Itotal is obtained over the azimuth angle, and each diffraction peak derived from the stereocomplex polylactic acid crystal appearing in the vicinity of 2θ = 12.0 °, 20.7 °, 24.0 °. The total sum ΣISCi of the integrated intensities was determined. From these values, the stereocomplex polylactic acid crystallinity was determined according to the following formula (vi).
Stereocomplex polylactic acid crystallinity (%) = ΣISCi / Itotal × 100 (vi)
For the crystallite size D, stereocomplex polylactic acid crystals are obtained according to the Scherrer equation (vii) below using the Bragg angle and half-value width of the diffraction peak derived from the stereocomplex polylactic acid crystal appearing around 2θ = 12.0 °. The child size Dsc was determined.
Dsc = K · λ / βcos θ (nm) (vii)
Dsc: Stereo complex polylactic acid crystallite size K: Scherrer constant λ: X-ray wavelength (Å)
β: Half width (broadening of diffraction lines)
θ: Bragg angle of diffraction line Note that ΣISCi was calculated by subtracting diffuse scattering due to background or amorphous in the total scattering intensity.

(4) Water resistance evaluation of hydrolysis modifier:
・ Water resistance evaluation using dimethyl sulfoxide 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 was added to the dissolved sample portion. Measured by HPLC or ¹ H-NMR.
NMR used ECA600 made from 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: GL Science Inertsil Ph-3 3 μm 4.6 mm × 150 mm (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 → 30min)
Water resistance was calculated from the following formula (viii) using the obtained amount of the agent after 5 hours.
Water resistance (%) = [Amount after 5 h treatment / Initial amount] × 100 (viii)
-Other water resistance evaluations (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 (iii).
Device: Nicolet iN10
Measurement method: Microscopic transmission method Field of view: 50 μm × 50 μm
Resolution: 4cm ^-1
Measurement wave number: 4000 to 740 cm ⁻¹
Number of integrations: 128 Sample preparation: The dissolved sample was placed on a barium fluoride plate to volatilize the solvent.

(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 (ix).
Reactivity (%) = [(carboxyl group concentration of polylactic acid for evaluation−carboxyl group concentration of resin composition) / carboxyl group concentration of polylactic acid for evaluation] × 100 (ix)

(6) High temperature hot water test:
300 mg of the resin composition and 12 ml of distilled water were charged in a sealed melting crucible (O-M Labtech Co., Ltd., MR-28, internal volume 28 ml) preheated to 110 ° C., sealed, and kept at a predetermined temperature of 175 ° C. in advance. The crucible was placed in a 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 the specified test temperature is taken as the test start time. Removed from the dryer.
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 inner sample and water were filtered using a 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. It used for the measurement and the above-mentioned DSC measurement. The weight of the non-aqueous component was determined from the following formula (x).
Weight of non-aqueous component (%) = [weight of filtrate after test / weight of initial resin composition] × 100 (x)
As for shape retention, when a hot water test at 175 ° C. is performed using a plurality of test pieces, preferably 5 or more, it is in a lump or partially fused state after the test. The case where each test piece was easily dispersed was defined as “good”.
When fibers were used as the resin composition, the heat shrinkage rate of the fibers after 2 hours at 175 ° C. was obtained from the following formula (xi).
Thermal shrinkage (%) = 100− [fiber length after treatment at 175 ° C. for 2 hours / initial fiber length] × 100 (xi)

(7) Propant dispersion stability evaluation The proppant dispersion stability of the fiber was evaluated by the following method.
Put 5.52 g of reduced water candy (Mitsubishi Corporation Foodtech, reduced water candy PO-10) and 6.48 g of distilled water into a 13.5 ml screw tube (As One, Laboran Screw Tube No. 4). Stir for minutes and adjust. 60 mg of fiber was added to the adjusted aqueous solution of candy and further stirred for 1 minute to prepare a fiber-dispersed aqueous solution of candy. Then, 5.76 g of proppant (manufactured by Azuwan, Alumina Ball HD-1) was added to the prepared fiber-dispersed candy aqueous solution and stirred for 1 minute to prepare a proppant / fiber-dispersed candy aqueous solution.
Place the adjusted screw tube on a horizontal table, measure the height of the aqueous solution and the height of the uppermost part where the proppant is dispersed in the aqueous solution after 60 minutes. Was calculated.
100- (the height of the uppermost portion where the proppant is dispersed) / (the height of the liquid surface of the aqueous solution) × 100
A change rate of less than 30% was particularly excellent, 30% or more and less than 40% was excellent, 40% or more and less than 50% passed, and 50% or more was rejected.

Hereinafter, the compounds used in this example will be described.
<Resin having autocatalytic action mainly composed of water-soluble monomer (component A)>
The following polylactic acid was produced and used as a resin (component A) having an autocatalytic action mainly composed of a water-soluble monomer.
[Production Example 1] Poly L-lactic acid resin:
To 100 parts by weight of L-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%), 0.005 parts by weight of tin octylate was added, and 180 ° C. in a reactor equipped with a stirring blade in a nitrogen atmosphere. The mixture was reacted at 0 ° 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 obtain chips, thereby obtaining a poly L-lactic acid resin.
The resulting poly L-lactic acid resin had a weight average molecular weight of 152,000, a melting enthalpy (ΔHmh) of 49 J / g, a melting point (Tmh) of 175 ° C., a glass transition point (Tg) of 55 ° C., and a carboxyl group concentration of 13. Equivalent / ton.

[Production Example 2] Poly D-lactic acid resin:
A poly D-lactic acid resin is obtained in the same manner as in Production Example 1 except that D-lactide (manufactured by Musashino Chemical Laboratory, Inc., optical purity 100%) is used instead of L-lactide in Production Example 1. It was. The resulting poly-D-lactic acid resin has a weight average molecular weight of 151,000, a melting enthalpy (ΔHmh) of 48 J / g, a melting point (Tmh) of 175 ° C., a glass transition point (Tg) of 55 ° C., and a carboxyl group concentration of 14 Equivalent / ton.

[Production Example 3] Stereocomplex polylactic acid (A1):
100 parts by weight of polylactic acid resin comprising 50 parts by weight of each of poly L-lactic acid resin and poly D-lactic acid resin obtained in Production Examples 1 and 2 and phosphoric acid-2,2′-methylenebis (4,6-di-tert) -Butylphenyl) sodium ("Adekastab (registered trademark)" NA-11: manufactured by ADEKA Corporation) 0.04 parts by weight was mixed with a blender, dried at 110 ° C for 5 hours, and vented twin screw extrusion with a diameter of 30 mm Machine [TEX30XSST manufactured by Nippon Steel Works, Ltd.], melt-extruded and pelletized at a cylinder temperature of 250 ° C., a screw speed of 250 rpm, a discharge rate of 5 kg / h, and a vent vacuum of 3 kPa, and stereocomplex polylactic acid (A1) Got.
The resulting stereocomplex polylactic acid resin (A1) has a weight average molecular weight of 130,000, a melting enthalpy (ΔHms) of 56 J / g, a melting point (Tms) of 220 ° C., a carboxyl group concentration of 16 equivalents / ton, and stereocomplex crystallization. The degree (S) was 100%.

[Production Example 4] Stereocomplex polylactic acid (A2):
50 parts by weight of each of the poly L-lactic acid resin and the poly D-lactic acid resin obtained in Production Examples 1 and 2 were dried at 110 ° C. for 5 hours, and a vent type twin-screw extruder having a diameter of 30 mmφ [(stock ) Nippon Steel Works TEX30XSST] was melt-extruded and pelletized at a cylinder temperature of 280 ° C., a screw rotational speed of 300 rpm, a discharge rate of 7 kg / h, and a vent vacuum of 3 kPa to obtain stereocomplex polylactic acid (A2).
The obtained stereocomplex polylactic acid (A2) had 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%. It was.

[Production Example 5] Stereocomplex polylactic acid (A3):
100 parts by weight of polylactic acid resin comprising 50 parts by weight of each of poly L-lactic acid resin and poly D-lactic acid resin obtained in Production Examples 1 and 2 and phosphoric acid-2,2′-methylenebis (4,6-di-tert) -Butylphenyl) sodium ("Adekastab (registered trademark)" NA-11: manufactured by ADEKA Co., Ltd.) 0.1 parts by weight was mixed with a blender, dried at 110 ° C. for 5 hours, and vented twin screw extrusion with a diameter of 30 mmφ Machine [TEX30XSST manufactured by Nippon Steel Works], pelletized by melt extrusion at a cylinder temperature of 285 ° C., a screw speed of 250 rpm, a discharge rate of 5 kg / h, and a vent vacuum of 3 kPa, and stereocomplex polylactic acid (A3) Got.
The resulting stereocomplex polylactic acid (A3) has a weight average molecular weight of 102,000, a melting enthalpy (ΔHms) of 58 J / g, a melting point (Tms) of 217 ° C., a carboxyl group concentration of 24 equivalent / ton, and a stereocomplex crystal. The degree of conversion (S) was 100%.
A4: Polylactic acid “NW3001D” manufactured by Nature Works (MW is 150,000, carboxyl group concentration is 22.1 equivalent / ton)
<Hydrolysis regulator (component B)>
The following additives were used as hydrolysis regulators (component B).
B1: DIPC (Bis (2,6-diisopropylphenyl) carbodiimide, manufactured by Kawaguchi Chemical Industry Co., Ltd.)
The water resistance of B1 was 100%, and the reactivity with acidic groups was 85.7%.

[Example 1]
91 parts by weight of stereocomplex polylactic acid (A1) and 9 parts by weight of DIPC (B1) were mixed and supplied to a vent type twin-screw extruder having a diameter of 30 mmφ [TEX30XSST manufactured by Nippon Steel, Ltd.], and the cylinder temperature was 230 ° C. The strand melt-extruded at a screw rotation speed of 300 rpm and a discharge rate of 7 kg / h was cut with a chip cutter to obtain a resin composition pellet. The size of the pellet was a cylindrical shape having a diameter of 3 mm and a height of 3 mm. This pellet was used for evaluation in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1. The proppant sedimentation test was not performed.

[Example 2]
The resin composition obtained in Example 1 was further melt-extruded at a cylinder temperature of 230 ° C. and spun from a spinneret having a nozzle diameter of 0.3 mm to obtain an undrawn yarn. Next, after heating with a hot roller having a temperature of 85 ° C. and stretching 4 times, heat-fixing was performed at a temperature of 190 ° C. using a non-contact heater to obtain long fibers. The obtained fiber diameter was 12 μm. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was used and evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1.

[Example 3]
90 parts by weight of stereocomplex polylactic acid (A1) and 10 parts by weight of DIPC (B1) are mixed and supplied to a vent type twin screw extruder [TEX30XSST manufactured by Nippon Steel Works, Ltd.] with a diameter of 30 mm, and the cylinder temperature is 230 ° C. The resin composition was obtained by melt extrusion at a screw speed of 300 rpm and a discharge rate of 7 kg / h. 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 (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, concentric structure with a round cross section). The number of holes in the die is 60, the diameter of the discharge part is 300 μm, the discharge amount of the core part is 20 g / min, the discharge amount of the sheath part is 11 g / min, the spinning speed is 600 m / min, the draw ratio is 4 times, the heat setting temperature Was 190 ° C. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1.

[Example 4]
91 parts by weight of stereocomplex polylactic acid (A2) and 9 parts by weight of DIPC (B1) were mixed and supplied to a vent type twin-screw extruder with a diameter of 30 mmφ [TEX30XSST manufactured by Nippon Steel, Ltd.], and the cylinder temperature was 230 ° C. The resin composition was obtained by melt extrusion at a screw speed of 300 rpm and a discharge rate of 7 kg / h. The obtained resin composition was further melt-extruded at a cylinder temperature of 230 ° C. and spun from a spinneret having pores with a nozzle diameter of 0.3 mm to obtain undrawn yarns. Next, after heating with a hot roller having a temperature of 85 ° C. and stretching 4 times, heat-fixing was performed at a temperature of 190 ° C. using a non-contact heater to obtain long fibers. The obtained fiber diameter was 12 μm. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1.

[Comparative Example 1]
9 parts by weight of DIPC (B1) is mixed with polylactic acid (A4) and supplied to a vent type twin screw extruder [TEX30XSST manufactured by Nippon Steel Works, Ltd.] with a diameter of 30 mmφ, the cylinder temperature is 230 ° C., the screw speed is 300 rpm, The strand melt-extruded at a discharge rate of 7 kg / h was cut with a chip cutter to obtain a resin composition pellet. The size of the pellet was a cylindrical shape having a diameter of 3 mm and a height of 3 mm. This pellet was used for evaluation in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1. The proppant sedimentation test was not performed. As a result of wide-angle X-ray diffraction analysis, no peak derived from the stereocomplex PLA crystal was observed, so the stereocomplex PLA crystal size was not quantified.

[Comparative Example 2]
The resin composition obtained in Comparative Example 1 was further melt extruded at a cylinder temperature of 220 ° C., and spun from a spinneret having pores with a nozzle diameter of 0.2 mm to obtain undrawn yarns. Then, after stretching 1.5 times in a hot water bath at a temperature of 75 ° C., the fiber was heat-set at a temperature of 120 ° C. using a heat setting roller to obtain long fibers. The obtained fiber diameter was 12 μm. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was used and evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1. Since the temperature at the peak of the melting peak was less than 200 ° C., the amount of heat of melting peak was not quantified. As a result of wide-angle X-ray diffraction analysis, no peak derived from the stereocomplex PLA crystal was observed, so the stereocomplex PLA crystal size was not quantified.

[Comparative Example 3]
A long fiber was obtained in the same manner as in Example 4 except that stereocomplex polylactic acid (A3) was used instead of stereocomplex polylactic acid (A2). The obtained fiber diameter was 12 μm. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was used and evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1.

[Comparative Example 4]
A stereocomplex polylactic acid (A1) was melt-extruded at a cylinder temperature of 230 ° C. and spun from a spinneret having a nozzle diameter of 0.3 mm to obtain an undrawn yarn. Next, after heating with a hot roller having a temperature of 85 ° C. and stretching 4 times, heat-fixing was performed at a temperature of 190 ° C. using a non-contact heater to obtain long fibers. The obtained fiber diameter was 12 μm. This fiber was cut into a fiber length of 7 mm to obtain a short fiber. This short fiber was evaluated in high-temperature hot water at 175 ° C. The evaluation results are shown in Table 1.

From these results, (a) stereocomplex PLA crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours is 50% or more, and stereocomplex PLA crystal size A hydrolysis regulator having a water resistance at 120 ° C. of 95% or more and a reactivity with acidic groups at 190 ° C. of 50% or more is used for sealing the acidic groups. Thus, it can be seen that the weight and shape of the resin composition are well maintained even after treatment in high-temperature hot water, and the proppant dispersibility is well maintained when fibers are used.
On the other hand, (a) the crystal structure analysis result by wide-angle X-ray diffraction analysis (WAXD) of the sample after the hydrothermal treatment at 175 ° C. for 2 hours does not satisfy the above conditions, or the water resistance at 120 ° C. is 95% or more. A resin composition that does not use a hydrolysis regulator having a reactivity with acidic groups at 190 ° C. of 50% or more for sealing acidic groups has a weight and shape of the resin composition after treatment in high-temperature hot water. It can be seen that the proppant dispersibility is not well maintained when fibers are not used.

  The resin composition and fiber of the present invention exhibit desired performance in oil field excavation technology, and can be suitably used as a fiber that imparts proppant transport performance, dispersibility, and dispersion stability, particularly in hydraulic fracturing applications.

w Weight m Molecular weight g Acidic group weight

Claims (8)

(A) Stereocomplex polylactic acid crystallinity determined by wide-angle X-ray diffraction analysis (WAXD) of a sample after hydrothermal treatment at 175 ° C. for 2 hours is 50% or more, and stereocomplex polylactic acid crystal size is 13 nm or more And
(B) A resin composition in which the weight of the non-aqueous component derived from the resin composition after 48 hours in 175 ° C. hot water is 20% or less.   It contains a resin (A component) having a self-catalytic action mainly composed of a water-soluble monomer and a hydrolysis regulator (B component), and the content of B component is 100 parts by weight in total of A component and B component. The resin composition according to claim 1, which is 0.5 to 20 parts by weight.   The resin composition according to claim 2, wherein the component A contains a stereocomplex phase formed by poly L-lactic acid and poly D-lactic acid.   The resin composition according to claim 2, wherein the component B is a carbodiimide compound. The resin composition according to claim 4, wherein the 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 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 (It is a combination of these and may contain a hetero atom. Each aromatic ring may be bonded by a substituent to form a cyclic structure.)   6. The resin composition according to claim 5, wherein the component B is bis (2,6-diisopropylphenyl) carbodiimide.   The molded article which consists of a resin composition as described in any one of Claims 1-6.   The molded article according to claim 7, wherein the shape is a fiber.

Images