阅读说明：本技术 共聚尼龙树脂及其制备方法和用途 (Copolymerized nylon resin and preparation method and application thereof ) 是由 高敬民 邓慧 刘浩宇 于 2019-08-22 设计创作，主要内容包括：本发明提供一种共聚尼龙树脂及其制备方法和用途,所述共聚尼龙树脂为包含如下述通式(Ⅰ)所示的重复结构单元、下述通式(Ⅱ)所示的重复结构单元和下述通式(Ⅲ)所示的重复结构单元的尼龙树脂。本申请中公开的尼龙树脂具有较好的尺寸稳定性、吸水率低、阻隔性能和耐热性能优良的优点。(The invention provides a copolymerized nylon resin, a preparation method and application thereof, wherein the copolymerized nylon resin is a nylon resin containing a repeating structural unit shown in a general formula (I), a repeating structural unit shown in a general formula (II) and a repeating structural unit shown in a general formula (III). The nylon resin disclosed in the application has the advantages of good dimensional stability, low water absorption, and excellent barrier property and heat resistance.)

1. A copolymerized nylon resin is characterized in that the copolymerized nylon resin is a nylon resin containing a repeating structural unit shown in a general formula (I), a repeating structural unit shown in a general formula (II) and a repeating structural unit shown in a general formula (III);

wherein R is a binary acid compound containing a benzene ring, a tricyclic ring and an imide ring;

a and b are both positive integers of 4 or more, and c is a positive integer of 2 or more.

2. The copolymerized nylon resin of claim 1, comprising one or more of the following features:

a is 10 or 12;

b is 6, 9, 10, 12 or 13;

c is 4 or 8;

the mass fraction of the repeating structural unit represented by the general formula (I) is 60 to 70%, the mass fraction of the repeating structural unit represented by the general formula (II) is 10 to 15%, and the mass fraction of the repeating structural unit represented by the general formula (III) is 15 to 30%, based on the total mass of the repeating structural unit represented by the general formula (I), the repeating structural unit represented by the general formula (II), and the repeating structural unit represented by the general formula (III).

3. The copolymerized nylon resin of claim 1, wherein R is selected from the following structures:

4. a method for preparing a copolymerized nylon resin according to any one of claims 1 to 3, comprising the steps of:

1) generating a salt by terephthalic acid and aliphatic diamine in water to obtain a component A;

2) forming salt by using dibasic acid with an R structure and aliphatic diamine in water to obtain a component B;

3) salifying m-xylylenediamine and aliphatic dibasic acid in water to obtain a component C;

4) and putting the component A, the component B, the component C and an initiator into a reaction kettle, and carrying out polycondensation reaction to obtain the copolymerized nylon resin.

5. The method of claim 4, comprising one or more of the following features:

in the step 1), the molar ratio of the terephthalic acid to the aliphatic diamine is (0.97-1) to 1;

in the step 2), the molar ratio of the dibasic acid with the R structure to the aliphatic diamine is (0.97-1) to 1;

in the step 3), the molar ratio of m-xylylenediamine to aliphatic dibasic acid is 1 (0.97-1).

6. The method of claim 4, wherein in step 4), the initiator is water.

7. The method of claim 4, wherein the initiator is added in an amount of 2 to 15 wt% based on the total amount of component A, component B and component C.

8. The process according to claim 4, characterized in that the polycondensation reaction is divided into three stages in sequence according to the control of temperature and pressure:

the first stage is as follows: the reaction temperature is 220-260 ℃, preferably 230-245 ℃, and the reaction pressure is 1.5-2.5 MPa; and a second stage: the reaction temperature is 280-330 ℃, preferably 290-320 ℃, and the reaction pressure is 1.5-2.0 MPa; and a third stage: the reaction temperature is 280-330 ℃, preferably 290-320 ℃, and the reaction pressure is-0.03-0.07 MPa.

9. Use of the copolymerized nylon resin according to any one of claims 1 to 3 for high-barrier packaging materials in the fields of food and medicine.

10. Use of the copolymerized nylon resin according to any one of claims 1 to 3 for a high barrier plastic fuel tank of an automobile.

Technical Field

The invention relates to the field of high molecular polymers, in particular to a copolymerized nylon resin and a preparation method and application thereof.

Background

Polyamide (PA), commonly known as nylon, is obtained by polycondensation of a dibasic acid with a diamine or an amino acid, and is a generic name for resins having a recurring amide group in the molecular chain. The nylon is the basic resin with the maximum yield, the maximum variety, the widest application and the excellent comprehensive performance in five general engineering plastics. The nylon can be the first of five engineering plastics, and has outstanding advantages in the aspects of mechanical property, chemical property, thermal property and the like mainly due to the excellent properties of the nylon. The nylon is developed for more than 70 years, and the application of the nylon is slowly expanded to the fields of films, engineering plastics and the like from spinning fibers.

With the progress of society, the demand of barrier materials is getting larger, and barrier polymer materials have more and more important status in the packaging field due to the advantages of light weight, easy forming and processing, difficult breakage, corrosion resistance and the like. At present, the plastic packaging material produced in China can not meet the requirement of international market competition in terms of high barrier property, and the requirement of domestic high barrier property packaging for food and medicine is higher and higher, so that the vigorous development of the high barrier property packaging material can obtain obvious social benefit and economic benefit.

The nylon has strong polar amide groups on the main chain, so that hydrogen bonds can be formed, the acting force among molecules is increased, and the nylon has good gas barrier property, good chemical stability and solvent resistance. However, nylon has poor moisture resistance, and the dimensional stability and barrier properties of polyamide products are affected by changes in ambient humidity. Nylon is widely used as a barrier material in automobile plastic fuel tanks and barrier packaging materials.

Chinese patent 201610452395.8 discloses a preparation method of a high-barrier graphene oxide/nylon nanocomposite material, which mainly comprises the following two steps: (1) graphene Oxide (GO) and nylon (PA) are reacted to prepare graphene oxide grafted nylon (GO-g-PA), namely, carboxyl and epoxy on the surface of GO are reacted with amino at the end of PA to graft PA to the surface of GO; (2) and (2) blending the PA, the GO-g-PA, the antioxidant and the ultraviolet absorber by virtue of double screws, and extruding and granulating to obtain the high-barrier-property nylon/graphene oxide (PA/GO) nano composite material. The barrier property and the mechanical strength of the composite material obtained by the method are improved to a certain degree, but the grafting rate is low, so that the barrier property of the material can be only slightly improved, and only black products can be prepared. More or less of the currently reported barrier nylon has a series of problems of poor dimensional stability, high water absorption, poor heat resistance and the like.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a copolymerized nylon resin, a preparation method and use thereof, which solve the problems of the prior art.

To achieve the above objects and other related objects, the present invention is achieved by the following technical solutions.

The invention provides a copolymerized nylon resin, which is a nylon resin comprising a repeating structural unit shown in a general formula (I), a repeating structural unit shown in a general formula (II) and a repeating structural unit shown in a general formula (III); has a structure as shown in I:

wherein R is a binary acid compound containing a benzene ring, a tricyclic ring and an imide ring;

a and b are both positive integers of 4 or more, and c is a positive integer of 2 or more.

According to the technical scheme, the method comprises one or more of the following characteristics:

a is 10 or 12;

b is 6, 9, 10, 12 or 13;

c is 4 or 8.

According to the technical scheme of the application, the mass fraction of the repeating structural unit shown in the general formula (I) is 60-70%, the mass fraction of the repeating structural unit shown in the general formula (II) is 10-15%, and the mass fraction of the repeating structural unit shown in the general formula (III) is 15-30% based on the total mass of the repeating structural unit shown in the general formula (I), the repeating structural unit shown in the general formula (II) and the repeating structural unit shown in the general formula (III).

According to the technical scheme of the application, R is selected from the following structures:

the application also discloses a method for preparing the copolymerized nylon resin, which comprises the following steps:

1) generating a salt by terephthalic acid and aliphatic diamine in water to obtain a component A;

2) forming salt by using dibasic acid with an R structure and aliphatic diamine in water to obtain a component B;

3) salifying m-xylylenediamine and aliphatic dibasic acid in water to obtain a component C;

4) and putting the component A, the component B, the component C and an initiator into a reaction kettle, and carrying out polycondensation reaction to obtain the copolymerized nylon resin.

According to the technical scheme, the method comprises one or more of the following characteristics:

in the step 1), the molar ratio of the terephthalic acid to the aliphatic diamine is (0.97-1) to 1;

in the step 2), the molar ratio of the dibasic acid with the R structure to the aliphatic diamine is (0.97-1) to 1;

in the step 3), the molar ratio of m-xylylenediamine to aliphatic dibasic acid is 1 (0.97-1).

According to the technical scheme, in the step 4), the initiator is water. Further, the addition amount of the initiator is 2 to 15 weight percent of the total amount of the component A, the component B and the component C.

According to the technical scheme, the polycondensation reaction process is divided into three stages according to the control of temperature and pressure in turn:

the first stage is as follows: the reaction temperature is 220-260 ℃, preferably 230-245 ℃, and the reaction pressure is 1.5-2.5 MPa;

and a second stage: the reaction temperature is 280-330 ℃, preferably 290-320 ℃, and the reaction pressure is 1.5-2.0 MPa;

and a third stage: the reaction temperature is 280-330 ℃, preferably 290-320 ℃, and the reaction pressure is-0.03-0.07 MPa.

The polycondensation reaction process is a process of increasing viscosity and molecular weight by draining water, and the reaction rate is controlled by controlling temperature and pressure in the polycondensation reaction, so that too slow or too fast viscosity increase is avoided. The temperature is divided into two stages, the higher the temperature the faster the water is drained and the faster the reaction rate. The pressure is the same, the later stage polymer viscosity is high, the drainage difficulty is caused, and the vacuum pumping is also used for facilitating the drainage of water.

The invention also discloses application of the copolymerized nylon resin in the fields of food and medicines for high-barrier packaging materials.

The invention also discloses the application of the copolymerized nylon resin in a high-barrier plastic oil tank of an automobile.

Compared with the prior art, the invention has the beneficial effects that:

(1) the binary acid compound containing benzene ring, tricyclic ring and imide ring and aliphatic diamine form salt to obtain copolymerization component B, and the introduction of large rigid planar structure can raise the stacking density and rigidity of nylon molecular chain and reduce the free volume of polymer, so as to obtain high-barrier and high-heat-resistance nylon resin.

(2) The copolymer has the advantages that the copolymer macromolecular main chain contains a large number of benzene rings, the molecular chain is rigid, the copolymer has excellent barrier property, and meanwhile, the copolymer has good dimensional stability and low water absorption rate.

(3) By adopting the technical scheme in the application, the proportion of A, B, C three components is changed, and a series of high-barrier and high-heat-resistant nylon resin meeting different performance requirements can be obtained.

Drawings

FIG. 1 is a chart showing an infrared spectrum of a copolymerized nylon resin obtained in example 1.

Detailed Description

The following description of the embodiments of the present invention is provided for illustrative purposes, and other advantages and effects of the present invention will become apparent to those skilled in the art from the present disclosure.

Before the present embodiments are further described, it is to be understood that the scope of the invention is not limited to the particular embodiments described below; it is also to be understood that the terminology used in the examples is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. Test methods in which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under conditions recommended by the respective manufacturers.

When numerical ranges are given in the examples, it is understood that both endpoints of each of the numerical ranges and any value therebetween can be selected unless the invention otherwise indicated. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In addition to the specific methods, devices, and materials used in the examples, any methods, devices, and materials similar or equivalent to those described in the examples may be used in the practice of the invention in addition to the specific methods, devices, and materials used in the examples, in keeping with the knowledge of one skilled in the art and with the description of the invention.