CN112574349B

CN112574349B - Rigid polyvinyl chloride-based copolymer, method for producing same, composition comprising same, and resin product made from composition

Info

Publication number: CN112574349B
Application number: CN201910932864.XA
Authority: CN
Inventors: 杨万泰; 张先宏; 宋长统; 马育红
Original assignee: Beijing University of Chemical Technology
Current assignee: Beijing University of Chemical Technology
Priority date: 2019-09-29
Filing date: 2019-09-29
Publication date: 2023-03-28
Anticipated expiration: 2039-09-29
Also published as: CN112574349A

Abstract

The present invention relates to a rigid polyvinyl chloride-based copolymer, a method for preparing the same, a composition comprising the same, and a resin article made of the composition. The hard vinyl chloride copolymer comprises: the vinyl chloride-based structural unit (a), the structural unit (b) based on the monomer represented by the following formula (1), and optionally the structural unit (c) based on the monomer represented by the following formula (2) are contained in an amount of 2 to 20% by mass in total relative to the total mass of the vinyl chloride-based copolymer. CH (CH) ₂ ＝CR ₁ COO(R ₂ O) _x R ₃ (1)CH ₂ ＝CR ₄ COOR ₅ (2)。

Description

Rigid polyvinyl chloride-based copolymer, method for producing same, composition comprising same, and resin product made from composition

Technical Field

The invention relates to the field of vinyl chloride resin synthesis, in particular to a hard vinyl chloride copolymer, a preparation method thereof, a composition comprising the hard vinyl chloride copolymer and a resin product prepared from the composition.

Background

Polyvinyl chloride (PVC) resin is prepared by polymerizing vinyl chloride monomer (VC) through free radicals, is one of five general resins in synthetic materials, has the yield which is only inferior to that of polyethylene and polypropylene, and belongs to the third general plastic variety in the world. Because of the characteristics of excellent chemical corrosion resistance, chemical stability, thermoplasticity, low manufacturing cost and the like, the PVC resin is widely applied to the fields of buildings, water supply, daily use and biomedicine.

Because the PVC molecular chain has larger polarity, the movement of the molecular chain is limited, and the processing difficulty of the PVC resin is increased. Therefore, plasticizers are added during the processing of polyvinyl chloride to reduce the melt viscosity and improve the flexibility of the PVC. At present, phthalate ester (PAEs) plasticizers, represented by dioctyl phthalate (DEHP), are mainly (about 70% or more) used in PVC resin processing. However, PAEs are toxic small-molecule plasticizers, and the plasticizer molecules are easy to migrate out to the surface of the PVC resin product during the use process of the product, so that the performance of the product is reduced. In particular, in the field of medical products, the small-molecule PAEs plasticizer gradually migrates out of the PVC resin products in the using process of the products and enters blood or body fluid or enters human bodies through other contact ways, and physiological harm is caused. At present, one of the research hotspots is to develop an environmentally friendly non-toxic/low-toxic plasticizer. In this regard, despite the rapid development, it is still difficult to solve the problem of migration of the plasticizer.

In view of the problem of migration of small molecule plasticizers, it is considered that an effective approach is to prepare a vinyl chloride-based copolymer by copolymerizing vinyl chloride with a monomer having a plasticizing function, thereby imparting self-plasticizing performance to a polyvinyl chloride resin. However, vinyl chloride is difficult to copolymerize with other monomers by means of conventional radical polymerization due to the intrinsic characteristics of vinyl chloride monomer, such as low monomer reactivity, large monomer chain transfer constant, high radical activity, and large reactivity difference with other conventional monomers. Therefore, modified polyvinyl chloride resins are currently mainly prepared by PVC post-graft modification, living polymerization techniques, and the like. In general, for the evaluation of the migration resistance of the modified polyvinyl chloride resin, it is considered whether or not there are easily-migrating components, such as shorter molecular chains or molecular chains having an excessively high content of the plasticizing component, in the resulting resin, which are generated by introducing the plasticizing component into the molecular chains.

For example, in non-patent document 1, a ring-opening reaction of caprolactone and propargyl alcohol is utilized, polycaprolactone (PCL-Alkyne) with alkynyl as a terminal group is synthesized first, then click reaction is performed on the polycaprolactone and PVC resin (PVC-N3) subjected to azide treatment under the radiation of ultraviolet light, PCL-Alkyne is successfully covalently grafted to a PVC side chain, and DSC tests show that the introduction of PCL significantly reduces the glass transition temperature of the PVC resin, and a good self-plasticizing effect is obtained. However, since the raw materials used in non-patent document 1 are expensive and the production method is complicated, this technique is mainly significant in scientific research and has no value for industrial application. Further, the azide-treated PVC actually sacrifices chlorine atoms in PVC, which greatly contribute to performance, and is disadvantageous for practical use.

For example, non-patent document 2 discloses a method for synthesizing a PVC-g-HPG graft copolymer having self-plasticizing properties by a click reaction using azide-treated PVC and an alkynyl-containing hyperbranched polyglycidyl ether. Due to the covalent bonding of HPG-C6 to PVC, the amorphous, dendritic structure of HPG-C6 and the plurality of polyether segments, the PVC-g-HPG graft copolymer shows excellent flexibility and mechanical properties. When the grafting amount of the HPG-C6 is 9 percent, the elongation at break is as high as 900 percent, the migration rate of the plasticizing component is almost zero, and the PVC resin with the self-plasticizing effect is realized. However, this technique has practical problems such as complicated process, high cost, and unsuitability for mass production, similar to the case of non-patent document 1.

For example, non-patent document 3 reports that a PVC-BA and PVC-EHA graft polymer is synthesized by modifying polyvinyl chloride using unstable chlorine in the PVC molecular chain as a reaction site and by graft-polymerizing and modifying PVC resin with butyl acrylate and 2-ethylhexyl acrylate by ATRP method. However, non-patent document 3 does not pay attention to the self-plasticizing performance. In addition, the transition metal compound tends to remain in the resin obtained by this technique, resulting in poor durability of the resin in actual use.

For example, in non-patent document 4, a polyvinyl chloride resin is modified by reactive blending, and a molten state blend of in-situ polymerization such as PVC/PMMA, PVC/PVAc, PVC/PBA, and PVC/PEHA is obtained in a twin-screw extruder from a PVC suspension having a monomer, an initiator, and a crosslinking agent adsorbed thereon. Because the reaction temperature in the extruder is 180 ℃, most of the obtained products are low molecular weight polymers, which play a role of plasticizing PVC, but PVC is easy to cause thermal decomposition in the process route, and the requirement on equipment is higher, so that the industrial production is difficult.

For example, in non-patent document 5, a butyl acrylate-vinyl chloride copolymer is prepared by suspension polymerization of a butyl acrylate monomer and vinyl chloride. However, according to the teaching of non-patent document 5, the amount of butyl acrylate used is only 10% or less. This is because when this value reaches 10%, the resulting resin tends to be blocked. In addition, the self-plasticizing properties are limited due to the low content of butyl acrylate-based structural units that can be incorporated into the resulting resin.

For example, non-patent document 6 describes that suspension copolymerization of VC and BA is studied by a single electron transfer-degenerate chain transfer living radical polymerization (SET-DTLRP) method, and a polyvinyl chloride-polybutyl acrylate random copolymer (PVC-PBA) having a uniform copolymerization composition is synthesized by a one-step method, and DMTA results indicate that the Tg of a PVC-PBA vinylchloride copolymer resin is also reduced from 70 ℃ to 25 ℃ as the content of PBA is gradually increased from 10% to 40%. Although the living polymerization method is suitable for adjusting the structure of the obtained copolymer resin, the technique has high requirements on the production process and high cost, and in addition, the residual metal ions in the product have the defects of complex post-treatment and the like, and the technique has no industrial application value.

As described above, most of the presently disclosed techniques are only in the scientific research stage, and the industrial utility value is not high; and techniques suitable for industrial production tend to have difficulty in achieving excellent self-plasticization and poor control over product structure.

Documents of the prior art

Non-patent document

Non-patent document 1: eur.polym.j.,2015,66,282-289.

Non-patent document 2: rapid Commun, 2016,37,2045-2051.

Non-patent document 3: J.Polym.Sci. Part A: polym.Chem.2003, 41,457-3462

Non-patent document 4: polymer.adv.Technol.2005, 16,495-504.

Non-patent document 5: chloralkali, china, 2013,2, 17-22.

Non-patent document 6: eur. Polym.j.,2015,73,202-211.

Disclosure of Invention

Problems to be solved by the invention

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide a rigid vinyl chloride-based copolymer having excellent self-plasticization, processability and mechanical properties, and further, a product made therefrom has excellent biological properties.

The present invention also aims to provide a method for producing the vinyl chloride copolymer, a resin composition comprising the vinyl chloride copolymer, and an article made of the resin composition.

Means for solving the problems

In order to achieve the above object, the present invention provides a rigid vinyl chloride copolymer having the following features [1] to [10], a method for producing the rigid vinyl chloride copolymer, a resin composition comprising the vinyl chloride copolymer, and a product made of the resin composition.

[1] A hard vinyl chloride copolymer, comprising: a vinyl chloride-based structural unit (a), a structural unit (b) based on a monomer represented by the following formula (1), and optionally a structural unit (c) based on a monomer represented by the following formula (2),

CH ₂ ＝CR ₁ COO(R ₂ O) _x R ₃ (1)

in the formula (1), R ₁ Selected from hydrogen and C1-6 straight-chain or branched alkyl; the number x of repeating units is an integer selected from 2 to 20, and each R ₂ Selected from linear or branched alkylene groups having 2 to 10 carbon atoms, which may be the same or different; r ₃ Selected from hydrogen and C1-4 linear or branched alkyl,

CH ₂ ＝CR ₄ COOR ₅ (2)

in the formula (2), R ₄ Selected from hydrogen and methyl, R ₅ Selected from the group consisting of a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched hydroxyalkyl group having 1 to 18 carbon atoms, a linear or branched alkoxyalkyl group having 1 to 18 carbon atoms, a linear or branched aminoalkyl group having 1 to 18 carbon atoms, and a cycloalkyl group having 3 to 18 carbon atoms which may or may not have a hetero atom;

the total content of the structural unit (b) and the structural unit (c) is 2 to 20% by mass based on the total mass of the hard vinyl chloride copolymer.

[2] The hard vinyl chloride-based copolymer according to [1], wherein the content of the structural unit (b) is 2 to 15% by mass based on the total mass of the hard vinyl chloride-based copolymer.

[3] The hard vinyl chloride-based copolymer according to [1] or [2], wherein the content of the structural unit (c) is 1 to 18% by mass based on the total mass of the hard vinyl chloride-based copolymer.

[4]According to [1]To [3]]The rigid vinyl chloride-based copolymer of the formula (1), wherein R is ₁ Selected from hydrogen and a linear or branched alkyl group having 1 to 4 carbon atoms; the number x of repeating units is an integer selected from 2 to 15, each R ₂ The alkylene groups may be the same or different and are selected from straight or branched alkylene groups having 2 to 6 carbon atoms.

[5] The hard vinyl chloride-based copolymer according to any one of [1] to [4], which has a tensile elongation at break of 140% or less.

[6] The hard vinyl chloride-based copolymer according to any one of [1] to [5], which has only one glass transition temperature.

[7] The hard vinyl chloride-based copolymer according to any one of [1] to [6], having a number average molecular weight of 40000 to 250000.

[8] A method for producing a hard vinyl chloride-based copolymer according to any one of [1] to [7], comprising: copolymerizing raw materials including vinyl chloride, the monomer represented by the formula (1), and optionally the monomer represented by the formula (2).

[9] A vinyl chloride-based resin composition comprising the hard vinyl chloride-based copolymer according to any one of [1] to [7 ].

[10] A resin article made of the vinyl chloride-based resin composition according to [9 ].

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention provides a rigid vinyl chloride-based copolymer having excellent self-plasticization, processability and mechanical properties. By copolymerizing vinyl chloride with the monomer represented by the above formula (1) at a specific ratio to introduce a plasticizing segment into a molecular chain of polyvinyl chloride, the resulting vinyl chloride-based copolymer not only has excellent mechanical properties satisfying the rigid vinyl chloride-based resin, but also can be well plasticized and molded at the time of processing even without adding a plasticizer, thereby avoiding deterioration of the properties of the resin product and environmental pollution due to migration of the plasticizer. In addition, the monomer represented by the above formula (1) also provides biocompatibility. Therefore, the product made of the vinyl chloride-based copolymer of the present invention may not only contain no plasticizer, but also have good biological properties (e.g., no cytotoxicity, good biocompatibility, no coagulation, etc.), thereby allowing the product made of the vinyl chloride-based copolymer of the present invention to have good biological properties useful for medical use.

Further, by further copolymerizing vinyl chloride and the monomer represented by the above formula (1) with the monomer represented by the above formula (2) which can be used as an auxiliary plasticizing monomer, the composition of the plasticizing segment in the vinyl chloride-based copolymer can be adjusted as desired, thereby further improving the self-plasticization property, processability, and mechanical properties (e.g., improved toughness) of the vinyl chloride-based copolymer and providing excellent water resistance and lower cost.

The present invention also provides a method for producing the above vinyl chloride-based copolymer, which realizes copolymerization of vinyl chloride and each comonomer by a simple method advantageous for industrial production.

The present invention further provides a vinyl chloride-based resin composition comprising the above vinyl chloride-based copolymer and a resin article made of the resin composition.

Detailed Description

The present invention will be described in detail below. The technical features described below are explained based on typical embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

in the present specification, the numerical range represented by "numerical value a to numerical value B" means a range including the end points of numerical values a and B.

In the present specification, the term "(meth) acrylate" is a concept covering both methacrylate and acrylate.

In the present specification, a repeating unit directly formed by polymerization of a monomer and a unit formed by chemically converting a part or all of substituents of the repeating unit formed by polymerization of a monomer into other substituents are collectively referred to as a "structural unit".

In the present specification, "%" means mass% unless otherwise specified.

In the present specification, the meaning of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

In this specification, "optional" or "optionally" means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Reference throughout this specification to "some particular/preferred embodiments," "other particular/preferred embodiments," "embodiments," or the like, means that a particular element (e.g., feature, structure, property, and/or characteristic) described in connection with the embodiment is included in at least one embodiment described herein, and may or may not be present in other embodiments. In addition, it is to be understood that the described elements may be combined in any suitable manner in the various embodiments.

< vinyl chloride copolymer >

The hard vinyl chloride copolymer of the present invention comprises: a structural unit (a) based on vinyl chloride, a structural unit (b) based on a monomer represented by the following formula (1), and optionally a structural unit (c) based on a monomer represented by the following formula (2).

CH ₂ ＝CR ₁ COO(R ₂ O) _x R ₃ (1)

In the formula (1), R ₁ Selected from hydrogen and linear or branched alkyl having 1 to 6 carbon atoms; the number x of repeating units is an integer selected from 2 to 20, each R ₂ Selected from linear or branched alkylene groups having 2 to 10 carbon atoms, which may be the same or different; r ₃ Selected from hydrogen and C1-4 linear or branched alkyl.

CH ₂ ＝CR ₄ COOR ₅ (2)

In the formula (2), R ₄ Selected from hydrogen and methyl, R ₅ Selected from the group consisting of a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched hydroxyalkyl group having 1 to 18 carbon atoms, a linear or branched alkoxyalkyl group having 1 to 18 carbon atoms, a linear or branched aminoalkyl group having 1 to 18 carbon atoms, and a cycloalkyl group having 3 to 18 carbon atoms which may or may not have a hetero atom.

In some embodiments, the hard vinyl chloride-based copolymer of the present invention includes a vinyl chloride-based structural unit (a) and a structural unit (b) based on the monomer represented by formula (1), and does not include a structural unit (c) based on the monomer represented by formula (2). In some preferred embodiments, the hard vinyl chloride-based copolymer of the present invention includes three structural units (a) based on vinyl chloride, structural units (b) based on a monomer represented by formula (1), and structural units (c) based on a monomer represented by formula (2).

The respective structural units in the vinyl chloride-based copolymer of the present invention are described in detail below.

(structural Unit (a))

The structural unit (a) is a vinyl chloride-based structural unit.

(structural Unit (b))

The structural unit (b) is a structural unit based on a monomer represented by the following formula (1).

CH ₂ ＝CR ₁ COO(R ₂ O) _x R ₃ (1)

In the vinyl chloride-based copolymer of the present invention, the structural unit (b) provides a plasticizing effect to reduce the polarity and rigidity of the polymer molecular chain, improving processability. The monomer represented by the above formula (1) has good copolymerizability with vinyl chloride, and can copolymerize with vinyl chloride in a wide range of proportions even in a conventional radical polymerization system.

In the formula (1), R ₁ Is selected from hydrogen and a linear or branched alkyl group having 1 to 6 carbon atoms, preferably from hydrogen and a linear or branched alkyl group having 1 to 4 carbon atoms, more preferably hydrogen and/or a methyl group.

In the formula (1), the number x of the repeating unit is an integer selected from 2 to 20, and from the viewpoint of obtaining more excellent self-plasticization and further suppressing segment migration, the number x of the repeating unit is preferably an integer selected from 2 to 15, more preferably an integer selected from 2 to 10. Each R ₂ The alkylene group is preferably a linear or branched alkylene group having 2 to 6 carbon atoms, more preferably a linear or branched alkylene group having 2 to 4 carbon atoms, from the viewpoint of more excellent self-plasticization and further suppression of segment migration. Each R ₂ May be the same or different.

R ₃ Selected from hydrogen and C1-4 linear or branched alkyl.

When each R is ₂ Meanwhile, specific examples of the monomer represented by the above formula (1) include, but are not limited to, polyethylene glycol methyl ether (meth) acrylate, polyethylene glycol ethyl ether (meth) acrylate, polyethylene glycol propyl ether (meth) acrylate, polyethylene glycol butyl ether (meth) acrylate, polyethylene glycol mono (meth) acrylate, polypropylene glycol methyl ether (meth) acrylate, polypropylene glycol ethyl ether (meth) acrylate, polypropylene glycol propyl ether (meth) acrylate, polypropylene glycol butyl ether (meth) acrylate, polypropylene glycol mono (meth) acrylate, polybutylene glycol methyl ether (meth) acrylate, polybutylene glycol ethyl ether (meth) acrylate, polybutylene glycol propyl ether (meth) acrylate, polybutylene glycol butyl ether (meth) acrylate, and polybutylene glycol mono (meth) acrylate. These monomers may be used alone or in combination of two or more.

When each R is ₂ At the same time, the monomer represented by the above formula (1) may be represented by the structural formula represented by the formula (1 a):

CH ₂ ＝CR ₁ COO(R _2a O) _a (R _2b O) _b R ₃ (1a)，

preferably, in formula (1 a), R ₁ And R ₃ As defined above; r _2a Is ethylene, R _2b The propylene group is used, the number of the repeating units a is 1-3, and the number of the repeating units b is 1-12.

(structural Unit (c))

The structural unit (c) is a structural unit based on a monomer represented by the following formula (2).

CH ₂ ＝CR ₄ COOR ₅ (2)

In the vinyl chloride-based copolymer of the present invention, the structural unit (c) provides an auxiliary plasticizing effect and further improves the mechanical properties and water resistance of the vinyl chloride-based copolymer.

In the formula (2), R ₄ Selected from hydrogen and methyl, R ₅ Selected from the group consisting of a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched hydroxyalkyl group having 1 to 18 carbon atoms, a linear or branched alkoxyalkyl group having 1 to 18 carbon atoms, a linear or branched aminoalkyl group having 1 to 18 carbon atoms, and a cycloalkyl group having 3 to 18 carbon atoms with or without a heteroatom such as oxygen, nitrogen, sulfur, etc.

Note that the "linear or branched alkoxyalkyl group having 1 to 18 carbon atoms" means an alkyl group having 1 to 18 carbon atoms in total, which is linear or branched, and in which an arbitrary hydrogen atom is substituted with an alkoxy group.

Specific examples of the monomer represented by the above formula (2) include, but are not limited to, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, sec-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, tert-pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, n-nonyl (meth) acrylate, isononyl (meth) acrylate, n-decyl (meth) acrylate, isodecyl (meth) acrylate, n-dodecyl (meth) acrylate, undecyl (meth) acrylate, isoundecyl (meth) acrylate, cyclohexyl (meth) acrylate, tert-butylcyclohexyl (meth) acrylate, cyclooctyl (meth) acrylate, glycidyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, methoxypropyl (meth) acrylate, ethoxypropyl (meth) acrylate, dimethylaminomethyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, and dimethylaminopropyl (meth) acrylate. These monomers may be used alone or in combination of two or more.

From the viewpoints of copolymerizability with other monomers and self-plasticizability and mechanical properties of the resulting copolymer, preferred are (meth) acrylate monomers having a glass transition temperature of their homopolymer of less than 60 ℃; among these, at least one of methyl acrylate, ethyl acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, n-octyl (meth) acrylate, isooctyl (meth) acrylate, hydroxyethyl (meth) acrylate, hydroxypropyl acrylate, dimethylaminoethyl (meth) acrylate, and hexyl (meth) acrylate is more preferable.

(content of structural units (a), (b) and (c))

The content of each of the structural unit (a), the structural unit (b) and the optional structural unit (c) is not particularly limited as long as the total content of the structural unit (b) and the structural unit (c) in the vinyl chloride-based copolymer of the present invention is 2 to 20 mass%, and can be appropriately selected according to the use of the vinyl chloride-based copolymer. The total content of the structural unit (b) and the structural unit (c) in the vinyl chloride-based copolymer is preferably 2 to 19% by mass, more preferably 3 to 18% by mass, from the viewpoint of better improving the self-plasticization and mechanical properties of the vinyl chloride-based copolymer and better making the vinyl chloride-based copolymer of the present invention suitable for the application field of rigid PVC.

In the present invention, in some preferred embodiments, the content of the structural unit (a) is preferably 80 to 98 mass%, more preferably 81 to 95 mass%, and still more preferably 84 to 92 mass%, relative to the total mass of the vinyl chloride-based copolymer. When the content of the structural unit (a) is more than the above-mentioned preferable range, the self-plasticization property, the processability and the biological property of the resulting vinyl chloride-based copolymer tend to be deteriorated. When the content of the structural unit (a) is less than the above range, the mechanical properties of the resulting vinyl chloride-based copolymer tend not to satisfy the requirements for the mechanical properties of the hard vinyl chloride-based resin.

In the present invention, in some preferred embodiments, the content of the structural unit (b) is preferably 2 to 15% by mass, more preferably 2.5 to 12% by mass, and still more preferably 3 to 10% by mass, relative to the total mass of the vinyl chloride-based copolymer. When the content of the structural unit (b) is more than the above-mentioned preferable range, although a significant plasticizing effect is exerted on the vinyl chloride-based copolymer, the mechanical properties of the resulting vinyl chloride-based copolymer tend to be lowered or even not meet the requirements of the rigid vinyl chloride-based resin in some application fields; when the content of the structural unit (b) is less than the above range, the self-plasticization property, the processability and the biological property of the resulting vinyl chloride-based copolymer tend to be deteriorated.

In a preferred embodiment in which the rigid vinyl chloride-based copolymer of the present invention includes the structural unit (c), the content of the structural unit (c) is preferably 1 to 18 mass%, more preferably 2 to 17 mass%, still more preferably 4 to 16.5 mass%, still more preferably 5 to 16 mass%, relative to the total mass of the vinyl chloride-based copolymer, from the viewpoint of better improvement in self-plasticization, mechanical properties, water resistance, and cost reduction.

In other preferred embodiments, the respective contents of the structural unit (a), the structural unit (b), and the structural unit (c) simultaneously satisfy the above-mentioned ranges with respect to the total mass of the vinyl chloride-based copolymer. For example, the content of the structural unit (a) is preferably 80 to 98% by mass, the content of the structural unit (b) is preferably 2 to 15% by mass, and the content of the structural unit (c) is preferably 1 to 18% by mass.

(structural units based on other monomers)

The hard vinyl chloride-based copolymer of the present invention may include a structural unit based on another monomer in addition to the structural unit (a) based on vinyl chloride, the structural unit (b) based on the monomer represented by formula (1), and optionally the structural unit (c) based on the monomer represented by formula (2), within a range that does not impair the technical effects of the present invention.

The other monomer is not particularly limited as long as it can be copolymerized with any one of vinyl chloride, the monomer represented by formula (1), and optionally the monomer represented by formula (2).

In the present invention, it is preferable that examples of the structural unit based on other monomer include, without being limited to, a structural unit based on a vinyl ether-based monomer, a structural unit based on a fluorine-containing (meth) acrylate-based monomer, a structural unit based on a maleimide-based monomer, a structural unit based on an acrylonitrile-based monomer, and a structural unit based on a carboxyl-containing monomer. These structural units may be present in the vinyl chloride-based copolymer of the present invention alone or in combination to impart desired properties to the vinyl chloride-based copolymer as necessary.

Structural units based on vinyl ether monomers

The structural unit based on the vinyl ether monomer is a structural unit based on a monomer represented by the following formula (3).

CH ₂ ＝CHOR ₆ (3)

In the formula (3), R ₆ Selected from the group consisting of a linear or branched alkyl group having 1 to 10 carbon atoms, a linear or branched cycloalkyl group having 3 to 10 carbon atoms and a linear or branched hydroxyalkyl group having 1 to 10 carbon atoms, which may be substituted with a halogen atom such as chlorine, bromine or fluorine. Preferably, R ₆ The alkyl group is selected from a linear or branched alkyl group having 1 to 8 carbon atoms, a linear or branched cycloalkyl group having 3 to 8 carbon atoms, and a linear or branched hydroxyalkyl group having 1 to 8 carbon atoms, and these may be substituted with a halogen atom such as chlorine, bromine, fluorine, or the like. Further, the hydrogen atom in formula (3) (means "CH" in formula (3)) ₂ Hydrogen atom in = CH- ") may be substituted with, for example, chlorine,Bromine, fluorine, and the like.

Examples of the monomer represented by the above formula (3) include, but are not limited to, vinyl methyl ether, vinyl ethyl ether, vinyl n-propyl ether, vinyl isopropyl ether, vinyl t-butyl ether, vinyl n-butyl ether, vinyl isobutyl ether, vinyl n-pentyl ether, vinyl cyclopentyl ether, vinyl cyclohexyl ether, 5-hydroxypentyl vinyl ether, 4-hydroxypentyl vinyl ether, 3-hydroxypentyl vinyl ether, 2-hydroxypentyl vinyl ether, 4-hydroxybutyl vinyl ether, 3-hydroxybutyl vinyl ether, 2-hydroxybutyl vinyl ether, 3-hydroxypropyl vinyl ether, 2-hydroxypropyl vinyl ether. Among them, vinyl n-butyl ether, vinyl isobutyl ether, 3-hydroxypropyl vinyl ether and 4-hydroxybutyl vinyl ether are preferred. These monomers may be used alone or in combination of two or more.

When the hard vinyl chloride-based copolymer of the present invention has a structural unit based on the monomer of formula (3) described above, it is possible to provide more excellent self-plasticization and also more excellent biocompatibility and lubricity.

Structural units based on fluorine-containing (meth) acrylate monomers

The structural unit based on the fluorine-containing (meth) acrylate monomer is a structural unit based on a monomer represented by the following formula (4).

CH ₂ ＝CR ₄ COOR ₇ (4)

In the formula (4), R ₄ As defined above, R ₇ Is selected from the group consisting of a linear or branched fluoroalkyl group having 1 to 18 carbon atoms, a fluorocycloalkyl group having 3 to 18 carbon atoms, and a fluorophenyl group, and is preferably selected from the group consisting of a linear or branched fluoroalkyl group having 1 to 12 carbon atoms, a fluorocycloalkyl group having 3 to 12 carbon atoms, and a fluorophenyl group. Further, the hydrogen atom in formula (4) (means "CH" in formula (4)) ₂ Hydrogen atom in =), for example, may be substituted with a halogen atom such as chlorine, bromine, fluorine, or the like.

Examples of the monomer represented by the above formula (4) include, but are not limited to, trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, pentafluoropropyl (meth) acrylate, pentafluorophenyl (meth) acrylate, hexafluorobutyl (meth) acrylate, heptafluorobutyl (meth) acrylate, octafluoropentyl (meth) acrylate, nonafluorohexyl (meth) acrylate, dodecafluoroheptyl (meth) acrylate, and tridecafluoroctyl (meth) acrylate. Among them, trifluoroethyl (meth) acrylate, pentafluorophenyl (meth) acrylate and hexafluorobutyl (meth) acrylate are preferable. These monomers may be used alone or in combination of two or more.

When the hard vinyl chloride-based copolymer of the present invention has a structural unit based on the monomer of formula (4) described above, it can provide excellent processing lubricity (e.g., reduction in adhesion to a twin roll or a screw, reduction in melt viscosity, etc.) and antibacterial/antifouling properties of the product.

Structural unit based on maleimide monomer

Examples of maleimide monomers that form structural units based on maleimide monomers include, without limitation, N-methylmaleimide, N-ethylmaleimide, N-N-propylmaleimide, N-isopropylmaleimide, N-cyclohexylmaleimide, N-laurylmaleimide, and N-phenylmaleimide. These monomers may be used alone or in combination of two or more.

Structural units based on acrylonitrile monomers

Examples of the acrylonitrile-based monomer forming the structural unit based on the acrylonitrile-based monomer include, but are not limited to, acrylonitrile, methacrylonitrile, ethacrylonitrile, and the like. These monomers may be used alone or in combination of two or more.

Building blocks based on carboxyl-containing monomers

Examples of the carboxyl group-containing monomer forming the structural unit based on the carboxyl group-containing monomer include, without limitation, acrylic acid, methacrylic acid, carboxyethyl (meth) acrylate, carboxypropyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. These monomers may be used alone or in combination of two or more.

(glass transition temperature (Tg))

The glass transition temperature of the vinyl chloride copolymer of the present invention can embody the structural characteristics of the copolymer and can be used to exhibit self-plasticization.

The vinyl chloride-based copolymer of the present invention preferably has only one glass transition temperature from the viewpoint of obtaining more excellent self-plasticization and processability. Further, the glass transition temperature is not particularly limited in general. However, the glass transition temperature is preferably below 80 ℃ and more preferably below 75 ℃. When the glass transition temperature is not less than the above upper limit, the self-plasticization property and the processability of the vinyl chloride-based copolymer of the present invention tend to deteriorate. The glass transition temperature is preferably 40 ℃ or higher, and more preferably 50 ℃ or higher, from the viewpoint of further ensuring the performance of the rigid vinyl chloride-based copolymer.

In the present invention, the glass transition temperature can be measured by a dynamic thermomechanical analyzer (DMTA).

(number average molecular weight)

The number average molecular weight of the vinyl chloride copolymer of the present invention is not particularly limited, and may be appropriately selected according to the application. From the viewpoint of achieving both more excellent mechanical properties and lower cost, the number average molecular weight of the vinyl chloride-based copolymer of the present invention is preferably 40000 to 250000, more preferably 50000 to 220000, and still more preferably 50000 to 200000. When the number average molecular weight is less than the above range, mechanical properties of the copolymer resin such as tensile strength and tensile elongation at break tend to decrease. When the number average molecular weight is more than the above range, it is necessary that the polymerization temperature tends to be too low, resulting in low conversion and increased production cost.

In the present invention, the number average molecular weight can be measured by Gel Permeation Chromatography (GPC) using polystyrene as a standard.

(Properties)

Polyvinyl chloride is generally processed with addition of a plasticizer, as understood in the art of resin processability, and therefore, polyvinyl chloride resins are classified into rigid polyvinyl chloride (for example, having a plasticizer content of less than 20%) and soft polyvinyl chloride (for example, having a plasticizer content of 20% or more) and the like according to the content of the additional plasticizer therein, and are expressed as differences in physical properties such as mechanical properties. However, since the vinyl chloride-based copolymer of the present invention can be processed excellently even without adding a plasticizer, whether the polyvinyl chloride-based copolymer satisfies the requirements for rigid PVC in the art is judged mainly from the range of tensile elongation at break in the present invention. Specifically, in the present invention, the tensile elongation at break of the vinyl chloride-based copolymer is preferably 140% or less, more preferably 10 to 140%, still more preferably 11 to 138%, and still more preferably 12 to 135% according to the test method of GB/T1040-2006.

In the present invention, the tensile strength of the vinyl chloride-based copolymer is preferably 30MPa or more, more preferably 35MPa or more, according to the test method of GB/T1040-2006.

In the present invention, the hardness of the vinyl chloride-based copolymer is preferably greater than 70, more preferably greater than 75, according to GB/T2411-2008 test method (Shore D).

More preferably, the hard vinyl chloride-based copolymer of the present invention satisfies all of the above physical property parameters at the same time.

< method for producing rigid vinyl chloride copolymer >

The method for producing a rigid vinyl chloride-based copolymer of the present invention is a method for producing the rigid vinyl chloride-based copolymer, including: copolymerizing raw materials comprising vinyl chloride, the monomer represented by the above formula (1), and optionally the monomer represented by the above formula (2).

Details of vinyl chloride, the monomer represented by formula (1), the monomer represented by formula (2), and other monomers are described above and will not be described herein.

Examples of copolymerization reactions of the present invention include, but are not limited to, block polymerization, random polymerization, graft polymerization, gradient polymerization. Among them, random polymerization is preferable from the viewpoint of more favorably exhibiting the technical effects of the present application, that is, the molecular chain of the hard vinyl chloride-based copolymer of the present invention preferably has a random structure. More preferably, the hard vinyl chloride-based copolymer of the present invention is a random copolymer.

The mechanism of the production method is not particularly limited as long as the hard vinyl chloride-based copolymer of the present invention can be obtained, and a general radical polymerization method, a living radical polymerization method, and the like can be employed. However, the preparation method of the rigid vinyl chloride-based copolymer of the present invention is based on a general radical polymerization mechanism from the viewpoint of facilitating industrial production.

As the polymerization method, any polymerization method that can be carried out by a radical polymerization mechanism, for example, emulsion polymerization, solution polymerization, suspension polymerization, bulk polymerization, slurry polymerization, gas phase polymerization, interface polymerization, and the like can be used. From the viewpoints of adjustment of molecular weight and copolymerization composition and productivity, suspension polymerization, bulk polymerization and emulsion polymerization are preferably employed.

(bulk polymerization method)

The bulk polymerization process of the present invention is a bulk polymerization process known in the art. Specifically, the bulk polymerization method of the present invention is a polymerization method in which a dispersion medium is not contained in a polymerization system, and preferably, the bulk polymerization method is carried out by polymerizing each monomer used in the present invention in the presence of an initiator.

In the case of the bulk polymerization method, the order of addition and the manner of addition of the monomers are not limited, and the monomers may be added together or may be added in portions in any combination.

Specific examples of initiators suitable for use in the bulk polymerization process include, without limitation: azo initiators such as azobisisobutyronitrile, azobisisovaleronitrile, azobisisoheptonitrile, and the like; examples of the organic peroxide initiator include t-butyl peroxyneoheptanoate, t-butyl peroxyneodecanoate, di-sec-butyl peroxydicarbonate, dicetyl peroxydicarbonate, t-amyl peroxyneodecanoate, t-butyl peroxypivalate, bis- (4-t-butylcyclohexyl) peroxydicarbonate, dicyclohexyl peroxydicarbonate, diisopropyl peroxydicarbonate, dibutyl peroxydicarbonate, bis (2-ethylhexyl) peroxydicarbonate, t-butyl 2-ethylhexanoate, ditetradecyl peroxydicarbonate, t-butyl peroxyacetate, isopropyl phenyl peroxyneodecanoate, di-t-butyl peroxide, cyclohexyl sulfonyl acetyl peroxide, dibenzoyl peroxide, diisobutyryl peroxide, 1, 3-tetramethylbutyl peroxyneodecanoate, di-3-methoxybutyl peroxydicarbonate, and 1, 3-tetramethylbutyl peroxypivalate. These radical initiators may be used alone or in combination of two or more. In particular, free radical initiators having a decomposition temperature of less than 80 ℃ are preferred.

The amount of the initiator to be used is preferably 0.001 to 4% by mass, more preferably 0.01 to 2% by mass, based on the total mass of the monomers.

The polymerization conditions may be appropriately selected depending on the monomer composition, the decomposition temperature of the initiator, and the like. The polymerization temperature is preferably from 0 to 100 ℃, more preferably from 10 to 90 ℃, most preferably from 30 to 80 ℃. The polymerization time is preferably 1 to 72 hours, more preferably 1 to 24 hours, and most preferably 1 to 12 hours.

(suspension polymerization method)

The suspension polymerization process of the present invention is a suspension polymerization process well known in the art. Preferably, the suspension polymerization method of the present invention is carried out in a state where agitation is applied to the polymerization system.

The dispersion medium in the suspension polymerization process may be water or a mixture of water and a water-soluble organic solvent. Examples of the water-soluble organic solvent may include, without limitation: alcohols such as methanol, ethanol, propanol, butanol, cyclohexanol, ethylene glycol, propylene glycol, glycerol, etc.; ketones such as acetone, butanone, cyclohexanone, etc.; polyhydric alcohol alkyl ethers such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether and propylene glycol monoethyl ether; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether; nitrogen-containing heterocyclic compounds such as N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1, 3-dimethylimidazolidinone, and epsilon-caprolactam; amides such as formamide, N-methylformamide, formamide and N, N-dimethylformamide; amines such as monoethanolamine, diethanolamine, triethanolamine, monoethylamine, diethylamine and triethylamine; sulfur-containing compounds such as dimethyl sulfoxide, sulfolane and thiodiethanol; propylene carbonate and ethylene carbonate.

The dispersion medium is preferably water from the viewpoint of easy recovery. As for water, various forms such as tap water, deionized water, distilled water, and the like can be employed.

The dispersant in the suspension polymerization method may be any known dispersant in the art, such as anionic dispersant, cationic dispersant, nonionic dispersant, and polymeric dispersant.

Specific examples of the dispersant may include, without limitation: water-soluble organic high molecular substances, for example, partially hydrolyzed polyvinyl alcohol, salts of polyacrylic acid or polymethacrylic acid, synthetic high molecules such as maleic anhydride/styrene copolymer, cellulose derivatives such as methylcellulose, hydroxymethylcellulose and hydroxypropylcellulose, natural high molecules such as gelatin, protein, starch and sodium alginate; and water-insoluble inorganic powders such as magnesium carbonate, calcium carbonate, barium sulfate, calcium phosphate, talc, kaolin; and the like. These dispersants may be used alone or in combination of two or more. In view of the particle size, shape, transparency and film-forming property of the product, it is preferable to use a water-soluble organic high molecular substance, and it is more preferable to use a mixture of polyvinyl alcohol and a cellulose derivative. The amount of the dispersant used is preferably 0.01 to 5% by mass, more preferably 0.05 to 3% by mass, relative to 100 parts by mass of the dispersion medium.

The monomer concentration in the system is preferably 10 to 60% by mass, more preferably 15 to 50% by mass, based on the total mass of the dispersion medium.

In the case of the suspension polymerization method, the order of addition and the manner of addition of the monomers are not limited, and the monomers may be added together or may be added in portions in any combination.

The kind of the initiator, the amount of the initiator used, and the polymerization conditions (polymerization temperature, polymerization time, etc.) each range suitable for the suspension polymerization method are the same as those in the above-mentioned "(bulk polymerization method)", and will not be described in detail herein.

(emulsion polymerization method)

The emulsion polymerization process of the present invention is well known in the art. Preferably, the emulsion polymerization method of the present invention is carried out in a state where agitation is applied to the polymerization system.

The kind of the dispersion medium is the same as in the above "(suspension polymerization method)", and will not be described in detail herein.

The monomer concentration in the system is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, based on the total mass of the dispersion medium.

The emulsifier in the emulsion polymerization process may be an emulsifier well known in the art. Specific examples of the emulsifier of the present invention may include, but are not limited to: nonionic emulsifiers such as polyoxyalkylene alkyl phenyl ether, polyoxyalkylene alkyl ether, polyoxyalkylene styrenated phenyl ether, polyoxyalkylene benzylated phenyl ether, polyoxyalkylene cumylphenyl ether, fatty acid polyglycol ether, polyoxyalkylene sorbitan fatty acid ester, sorbitan fatty acid ester and the like; anionic emulsifiers such as fatty acid soap, rosin acid soap, alkylsulfonate, alkylarylsulfonate, alkylsulfonate, alkylsulfosuccinate, and sulfate, phosphate, ether carboxylate, sulfosuccinate and the like of nonionic emulsifiers having a polyoxyalkylene chain; cationic emulsifiers, such as stearyltrimethylammonium salt, cetyltrimethylammonium salt, lauryltrimethylammonium salt, dialkyldimethylammonium salt, alkyldimethylbenzylammonium salt, alkyldimethylhydroxyethylammonium salt and the like.

The amount of the emulsifier used is preferably 0.5 to 15 mass%, more preferably 1.0 to 10 mass%, relative to 100 parts by mass of the dispersion medium.

In addition, the emulsion polymerization process of the present invention may not use an emulsifier, i.e., the emulsion polymerization process of the present invention may be based on a self-emulsion polymerization process.

In the case of the emulsion polymerization method, the order of addition and the manner of addition of the monomers are not limited, and the monomers may be added together or may be added in portions in any combination.

Specific examples of initiators suitable for use in the emulsion polymerization process include, without limitation: the initiator as described in the above "(bulk polymerization method)"; a redox initiator; persulfates, such as ammonium persulfate, potassium persulfate, and the like. These initiators may be used alone or in combination.

The polymerization conditions may be appropriately selected depending on the monomer composition, the decomposition temperature of the initiator, and the like. The polymerization temperature is preferably from 10 to 90 ℃ and most preferably from 30 to 80 ℃. The polymerization time is preferably 1 to 72 hours, more preferably 1 to 24 hours, and most preferably 1 to 12 hours.

< vinyl chloride resin composition >

The vinyl chloride resin composition of the present invention includes the above-mentioned hard vinyl chloride copolymer.

The vinyl chloride-based resin composition of the present invention may optionally include other components in addition to the hard vinyl chloride-based copolymer of the present invention, and examples of the other components include other resins such as other vinyl chloride-based resins, acrylic-based resins, vinyl-based resins, polyester-based resins such as polyethylene terephthalate, styrene-based resins, fluororesins, silicone resins, polyamide-based resins, polyimide-based resins, and the like; rubbers such as styrene-butadiene rubber, nitrile rubber, butyl rubber, chloroprene rubber, isoprene rubber, butadiene rubber, ethylene propylene diene rubber, silicone rubber; examples of the thermoplastic elastomer include olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, and fluoropolymer-based thermoplastic elastomers. They may be used alone or in combination of two or more. The content of the other components is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, still more preferably 10 parts by mass or less, and still more preferably 0 part by mass, relative to 100 parts by mass of the vinyl chloride-based resin composition.

The vinyl chloride-based resin composition of the present invention may further optionally include various additives generally known in the art, such as fillers, pigments, plasticizers, ultraviolet absorbers, light stabilizers, delusterants, surfactants, leveling agents, surface conditioners, degassing agents, heat stabilizers, antistatic agents, rust inhibitors, silane coupling agents, antifouling agents, antibacterial agents, foaming agents, crosslinking agents, lubricants, and the like, at any content. They may be used alone or in combination of two or more. In some preferred embodiments, the vinyl chloride-based resin composition of the present invention does not include a plasticizer since the vinyl chloride-based copolymer of the present invention has excellent self-plasticization.

The vinyl chloride-based resin composition of the present invention can be prepared by a method generally known in the art. For example, all the components constituting the vinyl chloride-based resin composition of the present invention are mixed using standard mixing equipment such as Banbury or Brabender mixers, extruders, kneaders, and two-roll mixers. The manner of preparation of the composition is not particularly limited, and the above-mentioned mixing may be performed by a single-stage or multi-stage manner according to the desired composition of the composition. The mixing temperature and the mixing speed for the above-mentioned mixing are also not particularly limited and may be appropriately selected according to the desired composition of the composition.

< resin product >

The resin product of the present invention is a rigid PVC molded product made of the vinyl chloride resin composition. In some embodiments, the resin article of the present invention is preferably a melt-molded article, for example, a molded article obtained by extrusion molding, injection molding, blow molding, die (pressure) molding, calender molding, or the like.

The resin product of the present invention can be used for various purposes known in the art, for example, PVC sheets, PVC pipes, PVC profiles, PVC containers, children's toys, etc.

In some preferred embodiments, the resin article of the present invention may be a product used in the medical field, for example, a luer connector, an indwelling needle, a specimen container, a drip chamber, and the like.

Examples

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to these examples.

< evaluation method >

The composition ratio of each structural unit of the hard vinyl chloride-based copolymer, the number average molecular weight and molecular weight distribution (PDI) of the copolymer, mechanical properties, self-plasticization, migration resistance, and biological properties were determined by the following methods.

(composition ratio of copolymer)

The composition ratio of the copolymer was measured by Brookfield AV400 NMR spectrometer (THF-d 8 as a solvent).

(number average molecular weight and molecular weight distribution (PDI) of copolymer)

The number average molecular weight and molecular weight distribution of the copolymer were determined by Waters-1515 gel chromatography using THF as eluent and polystyrene as standard.

(mechanical Properties)

100 parts of the vinyl chloride-based copolymers and 2 parts of the methyl tin mercaptide heat stabilizer of each of examples and comparative examples were kneaded with a two-roll kneader, and then hot-pressed at 175 ℃ for 5 minutes and cold-pressed for 5 minutes to obtain sample pieces. The prepared sample wafer is cut into dumbbell-shaped sample strips, and the tensile strength and the elongation at break are measured according to GB/T1040-2006.

(self-plasticization property)

The self-plasticization was evaluated by the glass transition temperature. The sample pieces were prepared in the same manner as in the evaluation of the mechanical properties described above. Cutting the obtained sample into sample strips with the width of 5mm and the length of 75mm, and testing by using DMTA 2980, wherein the testing mode is a stretching mode, the frequency of the testing condition is 1Hz, and the temperature range is-60-100 ℃.

(migration resistance)

In the present invention, whether or not a molecular chain which is easily migrated by introducing a plasticizing segment into the molecular chain is present in the vinyl chloride copolymer is considered for the evaluation of the migration resistance.

The vinyl chloride-based copolymers of examples and comparative examples were sampled according to the sampling method in the evaluation of mechanical properties to obtain sample pieces, and each sample piece was cut in parallel into 2 groups of 5 small pieces, weighed and recorded. And (3) respectively soaking the 2 groups of cut sample blocks into ethanol and water, soaking at normal temperature for 48h, finally taking out, drying in an oven at 50 ℃ for 24h, and weighing. The percentage of the mass difference before and after soaking (in ethanol or water) of the sample piece to the mass of the sample piece before soaking was calculated, and the average of the percentages was defined as the migration rate. It should be noted that the migration rate should be less than or equal to 0.1%.

(biological)

The sample pieces were prepared in the same manner as in the evaluation of the mechanical properties described above. The plaques were subjected to hemolytic and cytotoxic tests according to GB/T16886.5 and GB/T16886.12.

It is noted that the hemolysis ratio values in GB/T16886.5 and GB/T16886.12 require R <5%. In the present invention, 2.5% < R <5% is defined as good, 0.5% < R <2.5% is defined as excellent, and R <0.5% is defined as optimal.

< example 1>

Into a 200ml stainless steel microreactor having an internal volume and equipped with a stirrer, 100g of deionized water, 10.4g of a 2 mass% aqueous PVA solution, 0.042g of hydroxypropyl methylcellulose, 0.05g of azobisisobutyronitrile, and 1.62g of polypropylene glycol monomethacrylate having a molecular weight of 375 (PPGMA-375, in the case of x =5 in formula (1)), the air in the microreactor was replaced by nitrogen gas for 5 minutes. Then 52.38g of VC monomer is introduced into the reaction kettle. After pre-stirring for 60min, heating to 70 ℃ to start polymerization, wherein the mass ratio VC of monomer charge to PPGMA-375=97 is defined as follows, and the polymerization reaction time is 8 hours. After completion of the polymerization, the unreacted VC monomer was recovered, and the polymerization product was washed with a large amount of deionized water and ethanol alternately to obtain 50.5g of a vinyl chloride-based copolymer as white solid particles, which had a composition of: the content of the structural unit (a) was 97.5% by mass and the content of the structural unit (b) was 2.5% by mass based on the total mass of the vinyl chloride-based copolymer.

< example 2>

51.2g of a vinyl chloride-based copolymer having white solid particles and a composition of VC: PPGMA-375= 5 and a polymerization reaction time of 7.5 hours were obtained in the same manner as in example 1, except that the charge mass ratio of VC to PPGMA-375 was changed to VC: the content of the structural unit (a) was 96.4 mass% and the content of the structural unit (b) was 3.6 mass% based on the total mass of the vinyl chloride-based copolymer.

< example 3>

49.5g of a vinyl chloride-based copolymer in the form of white solid particles having a composition of, by mass, VC: PPGMA-375=90 and a polymerization reaction time of 7.5 hours were obtained in the same manner as in example 1, except that the charge mass ratio of VC to PPGMA-375 was changed to VC: the content of the structural unit (a) was 88.2 mass% and the content of the structural unit (b) was 11.8 mass% based on the total mass of the vinyl chloride-based copolymer.

< example 4>

47.8g of a vinyl chloride-based copolymer having white solid particles and a composition of, by weight, VC to PPGMA-375 was obtained in the same manner as in example 1, except that the charge mass ratio of VC to PPGMA-375 was changed to VC: PPGMA-375=80 and the polymerization time was 8.2 hours: the content of the structural unit (a) was 82.1% by mass and the content of the structural unit (b) was 17.9% by mass, based on the total mass of the vinyl chloride-based copolymer.

< example 5>

Butyl Acrylate (BA) which is a source of the structural unit (c), PPGMA-375 and VC were copolymerized, 100g of deionized water, 10.4g of an aqueous solution of PVA 2 mass%, 0.042g of hydroxypropyl methylcellulose, 0.05g of azobisisobutyronitrile, 5.4g of PPGMA-375 and 5.4g of BA were charged into a stainless steel microreactor having an internal volume of 200ml and equipped with a stirring blade, and the air in the reactor was replaced by introducing nitrogen gas for 5 minutes. Then 43.2g of VC monomer is introduced into the reaction kettle. After pre-stirring at room temperature for 60min, heating to 70 ℃ to start polymerization, wherein the mass ratio of the monomers VC to PPGMA-375 (VC/BA = 80). After completion of the polymerization, the unreacted VC monomer was recovered, and the polymerization product was washed with a large amount of deionized water and ethanol alternately to obtain 51.5g of a vinyl chloride-based copolymer as white solid particles, whose composition was: the content of the structural unit (a) was 82.1 mass%, the content of the structural unit (b) was 11.9 mass%, and the content of the structural unit (c) was 6.0 mass%, based on the total mass of the vinyl chloride-based copolymer.

< example 6>

A vinyl chloride-based copolymer 51.7 having white solid particles and a composition of the copolymer was obtained in the same manner as in example 5, except that the mass charge ratio of VC, PPGMA-375 and BA was changed to VC: PPGMA-375: the content of the structural unit (a) was 82.5% by mass, the content of the structural unit (b) was 2.3% by mass, and the content of the structural unit (c) was 15.2% by mass, based on the total mass of the vinyl chloride-based copolymer.

< example 7>

A vinyl chloride-based copolymer having white solid particles was obtained in the same manner as in example 5 except that the mass charge ratio of VC, PPGMA-375 and BA was changed to VC: PPGMA-375: the content of the structural unit (a) was 82.2 mass%, the content of the structural unit (b) was 4.0 mass%, and the content of the structural unit (c) was 13.8 mass%, based on the total mass of the vinyl chloride-based copolymer.

< example 8>

A vinyl chloride-based copolymer (48.3 g) was obtained as white solid particles, having a composition in the same manner as in example 5, except that the mass charge ratio of VC, PPGMA-375 and BA was changed to VC: PPGMA-375: the content of the structural unit (a) was 81.8 mass%, the content of the structural unit (b) was 16.5 mass%, and the content of the structural unit (c) was 1.7 mass%, based on the total mass of the vinyl chloride-based copolymer.

< example 9>

A vinyl chloride-based copolymer having white solid particles 52.5g and a composition of VC, PPGMA-375 and BA in the same manner as in example 5 was obtained except that the mass charge ratio of VC: PPGMA-375 to BA was changed to that of VC: PPGMA-375: the content of the structural unit (a) was 88.8 mass%, the content of the structural unit (b) was 6.9 mass%, and the content of the structural unit (c) was 4.3 mass%, based on the total mass of the vinyl chloride-based copolymer.

< example 10>

A vinyl chloride-based copolymer having white solid particles (52.9 g) and a composition of VC, PPGMA-375 and BA in a similar manner to example 5 was obtained except that the mass charge ratio of VC, PPGMA-375 to BA, i.e., VC: PPGMA-375, was changed by the following polymerization reaction time of 8.6 hours: the content of the structural unit (a) was 89.2 mass%, the content of the structural unit (b) was 3.2 mass%, and the content of the structural unit (c) was 7.6 mass%, based on the total mass of the vinyl chloride-based copolymer.

< example 11>

A vinyl chloride-based copolymer having white solid particles (53.1 g) was obtained in the same manner as in example 5, except that the mass charge ratio of VC, PPGMA-375 to BA, VC: PPGMA-375, was changed to that of VC: PPGMA-375: the content of the structural unit (a) was 88.6% by mass, the content of the structural unit (b) was 1.2% by mass, and the content of the structural unit (c) was 10.2% by mass, based on the total mass of the vinyl chloride-based copolymer.

< example 12>

A vinyl chloride-based copolymer (50.3 g) having white solid particles and a composition of, for example, 50.3g was obtained in the same manner as in example 5, except that PPGMA-375 was changed to polyethylene glycol monomethacrylate (PEGMA-475, where x =9 in formula (1)): the content of the structural unit (a), the content of the structural unit (b), and the content of the structural unit (c) were 82.2% by mass, 9.9% by mass, and 7.9% by mass, respectively, based on the total mass of the vinyl chloride-based copolymer.

< comparative example 1>

51.5g of a vinyl chloride-based copolymer having white solid particles and a composition of methoxyethyl methacrylate (MOEMA) was obtained in the same manner as in example 1 except that PPGMA-375 was changed to the one having VC: MOEMA =90 and the polymerization time was 8.3 hours: the content of the structural unit (a) was 91.7% by mass and the content of the structural unit based on MOEMA was 8.3% by mass, based on the total mass of the vinyl chloride-based copolymer.

In table 2, although the MOEMA-based structural unit does not satisfy the structural unit (b) of the present invention, the MOEMA-based structural unit is also denoted as the structural unit (b) for convenience.

< comparative example 2>

52.3g of a vinyl chloride-based copolymer having white solid particles and a composition of not using PPGMA-375, except that the charge mass ratio of VC to BA was VC: BA =90 and the polymerization time was 8.0 hours, was obtained in the same manner as in example 5: the content of the structural unit (a) was 90.6% by mass and the content of the structural unit (c) was 9.4% by mass, based on the total mass of the vinyl chloride-based copolymer.

< comparative example 3>

A vinyl chloride copolymer (50.9 g) was obtained as white solid particles in the same manner as in example 1, except that PPGMA-375 was changed to polypropylene glycol monomethacrylate (PPGMA-1500) having a molecular weight of 1500, and the charge mass ratio of VC to PPGMA-1500, VC: PPGMA-1500=90, and the polymerization time was 8.2 hours: the content of the structural unit (a) was 94.6% by mass and the content of the structural unit based on PPGMA-1500 was 5.4% by mass, based on the total mass of the vinyl chloride-based copolymer.

In addition, in Table 2, although the PPGMA-1500-based structural unit does not satisfy the structural unit (b) of the present invention, for convenience, the PPGMA-1500-based structural unit is also labeled as the structural unit (b).

< comparative example 4>

A vinyl chloride-based copolymer having white solid particles 51.5g and a composition of VC, PPGMA-375 and BA in the same manner as in example 5 was obtained, except that the mass charge ratio of VC: PPGMA-375 to BA was changed to VC: PPGMA-375: the content of the structural unit (a) was 68.8% by mass, the content of the structural unit (b) was 5.3% by mass, and the content of the structural unit (c) was 25.9% by mass, based on the total mass of the vinyl chloride-based copolymer.

In the above examples and comparative examples, the monomer compositions involved in the polymerization were different from each other. The polymerization time varies depending on the monomer composition in order to complete the reaction as much as possible.

As can be seen from the results of tables 1 and 2, the vinyl chloride-based copolymer obtained in each example satisfying the requirements of the present invention satisfies the conventional requirements for rigid PVC while having excellent self-plasticization, mechanical properties, migration resistance, and biological properties. In addition, according to visual observation, the samples made from the copolymers obtained in examples 1 to 10, 12 were excellent in transparency; however, the transparency of the sample made of the copolymer obtained in example 11 is lowered due to the small content of the structural unit (b), and the application thereof to the field where transparency is required is limited.

In addition, the suspension polymerization product having good morphology, i.e., the vinyl chloride-based copolymer of the present invention can be obtained by the industrially conventional technique in each of the examples of the present invention.

As can be seen from the comparison between example 1 and comparative examples 1 and 3, in comparative example 1, molecular chains of PMOEMA, which is a homopolymer, exist in the copolymer resin due to poor copolymerizability of MOEMA with vinyl chloride, and thus a small amount of bleeding out occurs in ethanol. Meanwhile, the self-plasticizing performance of the obtained product is reduced due to the small molecular monomer in MOEMA. In comparative example 3, PPGMA-1500 was poor in copolymerizability with vinyl chloride due to the large number x of repeating units, and the resulting product was partially caked and showed two glass transition temperatures in the Tg results.

As can be seen from the comparison among examples 9, 10, 11 and comparative example 2, in comparative example 2, the elongation at break of the resulting resin is low, and the self-plasticizing effect is insufficient; further, the transparency of the sample sheet made of the copolymer obtained in comparative example 2 was inferior to that of example 11.

As can be seen from the comparison between examples 1 to 11 and comparative example 4, in comparative example 4, the total content of the structural unit (b) and the structural unit (c) is greater than the range of the present invention, the elongation at break of the resulting resin exceeds 140%, the tensile strength is less than 30MPa, the Tg is also less than 40 ℃, and the technical index of rigid PVC is not satisfied.

Note that the vinyl chloride-based copolymers obtained in each of comparative examples 1 to 3 were not evaluated for biological properties because of their poor self-plasticization and/or mechanical properties. This is because expensive non-biotoxic plasticizers need to be added to these resins during processing to make possible the application in the medical field, which, however, is not the desired technical effect of the present application.

TABLE 1

TABLE 2

Note: in table 2, in comparative example 1, the amount marked by "(b)" is the amount based on the structural unit of MOEMA; in comparative example 3, the amount marked by "(b)" is the amount based on the structural unit of PPGMA-1500. In comparative example 4, the hardness of the obtained sample piece was too small to be suitable for shore D hardness test, and thus the hardness value was shore a hardness.

The above-mentioned embodiments are intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above-mentioned embodiments are only examples of the present invention, and are not intended to limit the present invention, and any modifications, equivalent substitutions, improvements and the like within the spirit and scope of the present invention should be included.

Claims

1. A hard vinyl chloride copolymer, comprising: a structural unit (a) based on vinyl chloride, a structural unit (b) based on a monomer represented by the following formula (1), and a structural unit (c) based on a monomer represented by the following formula (2),

CH ₂ =CR ₁ COO(R ₂ O) _x R ₃ (1)

in the formula (1), R ₁ Selected from hydrogen and straight chain or branched chain alkyl with 1 to 6 carbon atoms; the number x of the repeating units is an integer selected from 2 to 20, and each R ₂ Selected from linear or branched alkylene groups having 2 to 10 carbon atoms, which may be the same or different; r is ₃ Selected from hydrogen and linear or branched alkyl groups having 1 to 4 carbon atoms,

CH ₂ =CR ₄ COOR ₅ (2)

in the formula (2), R ₄ Selected from hydrogen and methyl, R ₅ Selected from the group consisting of a linear or branched alkyl group having 1 to 18 carbon atoms, a linear or branched hydroxyalkyl group having 1 to 18 carbon atoms, a linear or branched alkoxyalkyl group having 1 to 18 carbon atoms, a linear or branched aminoalkyl group having 1 to 18 carbon atoms, and a linear or branched aminoalkyl group having or not having a heteroatomCycloalkyl with the number of 3 to 18;

the total content of the structural unit (b) and the structural unit (c) is 2 to 20 mass%, the content of the structural unit (b) is 2 to 15 mass%, and the content of the structural unit (c) is 1 to 18 mass%, based on the total mass of the hard vinyl chloride copolymer;

the sum of the contents of the respective structural units in the hard vinyl chloride copolymer is 100 mass%;

the hard vinyl chloride copolymer has a tensile elongation at break of 140% or less.

2. The hard vinyl chloride-based copolymer according to claim 1, wherein the content of the structural unit (b) is 2.5 to 12% by mass based on the total mass of the hard vinyl chloride-based copolymer.

3. The hard vinyl chloride-based copolymer according to claim 1 or 2, wherein the content of the structural unit (c) is 2 to 17 mass% with respect to the total mass of the hard vinyl chloride-based copolymer.

4. The hard vinyl chloride-based copolymer according to claim 1 or 2, wherein R in the formula (1) ₁ Selected from hydrogen and straight chain or branched chain alkyl with 1 to 4 carbon atoms; the number x of the repeating units is an integer selected from 2 to 15, and each R ₂ The alkylene groups may be the same or different and are selected from straight or branched alkylene groups having 2 to 6 carbon atoms.

5. The rigid vinyl chloride-based copolymer according to claim 1 or 2, characterized in that the rigid vinyl chloride-based copolymer has only one glass transition temperature.

6. The rigid vinyl chloride-based copolymer according to claim 1 or 2, wherein the rigid vinyl chloride-based copolymer has a number average molecular weight of 40000 to 250000.

7. A process for preparing a rigid vinyl chloride-based copolymer according to any one of claims 1 to 6, characterized in that it comprises: copolymerizing raw materials including vinyl chloride, the monomer represented by the formula (1), and the monomer represented by the formula (2).

8. A vinyl chloride-based resin composition comprising the hard vinyl chloride-based copolymer according to any one of claims 1 to 6.

9. A resin article characterized by being produced from the vinyl chloride-based resin composition according to claim 8.