BG3174U1 - Thermoplastic composite and multilayer pipes produced therefrom - Google Patents

Abstract

The utility model relates to a thermoplastic composite of a copolymer of vinyl acetate and ethylene vinyl alcohol with inorganic fillers and/or reinforcing components, characterized in that it contains 3-15 wt. % carbon fibers, from 0 to 9.9 basalt fiber and from 15 wt. % to 35 wt. % binders, where the carbon fibers can be cut or ground. The binders are based on polypropylene and its copolymers with ethylene and polar co-monomers. The utility model also relates to multilayer pipes in which at least one layer is produced from the disclosed thermoplastic composite. An advantage of the described thermoplastic composite is that it has a reduced coefficient of linear thermal expansion.

Description

Field of technology

The utility model relates to a thermoplastic composite of a copolymer of vinyl acetate and ethylene vinyl alcohol with inorganic fillers and / or reinforcing components and multilayer pipes manufactured therefrom.

BACKGROUND OF THE INVENTION

Thermoplastic composites are prepared with various organic fillers, for example wood flour, but mostly with inorganic fillers, the most common of which is calcium carbonate and / or reinforcing components, which include mainly glass fibers and talc.

The use of inorganic fillers and reinforcing components in thermoplastic composites is currently a widespread technology. However, if the fillers are to be highly effective and significantly affect the mechanical and other physical properties, they must be used in concentrations of at least 20-30 wt. %. This in turn makes them expensive, especially given the increased density of the material filler or reinforcing filler with inorganic substances. The densities of polyolefins, in particular polypropylene and polyethylene as typical representatives, are in the range of 890-960 kg / m ³ , and the values for the densities of inorganic fillers and reinforcing components are usually in the range of 2250-2600 kg / m ³ .

In thermoplastic composites, the aim is usually to improve the mechanical properties of the material. Less commonly, the goal is to improve and / or alter other physical properties. It is also possible to aim for a change in electrical performance. In this case, efforts are usually directed to reduce the surface and / or internal electrical resistance. Usually one of the forms of carbon is used - highly conductive soot. Soot thermoplastic composites produce not only electrically conductive but also thermally conductive elements, usually in the form of tubes or bags, due to the increased heat absorption or transfer of heat contained in the soil, water or air. Liquids, most often water, pass through the heat exchange elements and thus transfer the energy for subsequent use, for example for heating buildings and water for technical purposes.

Of the other forms of carbon, carbon fiber should be considered. Their use as reinforcing components in plastics is usually in order to improve the mechanical properties of the resulting composites. The use of carbon fiber allows the production of pipes with a reduced coefficient of linear thermal expansion, as already described in a utility model from the Czech Republic № 27700 (issued on 12.01.2015). Another physical property of plastic pipes is the diffusion of oxygen through the walls of the pipe into the liquid carried. The reduction of this diffusion is usually overcome by creating a multilayer pipe structure by adding a layer of polyvinyl alcohol or polyamide. Layered fillers such as montmorillonite can also be added to these polymers.

Technical essence of the utility model

The object of the present utility model is to create a thermoplastic composite with a reduced coefficient of linear thermal expansion (hereinafter referred to as CLTE) to be used mainly for the production of pipes, which will also form a barrier against the diffusion of oxygen through the wall. of the pipe in the liquid to be transported. This, according to the present utility model, is achieved by a thermoplastic composite of a copolymer of vinyl acetate and vinyl alcohol with ethylene with inorganic fillers and / or reinforcing components, characterized in that it contains from 3 to 15 wt. % carbon fiber, from 0 to 9.9 wt. % basalt fiber and from 15 to 35 wt. % binders.

From a dosage point of view, the use of ground carbon fiber is recommended.

From the point of view of processability, it is advisable to use chopped carbon fiber.

In order to reduce CLTE, it is expedient for the tube to contain carbon fibers in at least one layer, which forms the middle layer in the three-layer tube.

4337 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

The binders are based on polypropylene and its copolymers with ethylene and polar co-monomers. Internal water distribution materials are usually made of polypropylene and its copolymers with ethylene. The copolymers can be heterophase or random. The use of polypropylene homopolymers is also possible.

Since polyvinyl alcohol and its copolymers with vinyl acetate are chemically polar polymers and the materials based on polypropylene and its copolymers with ethylene are chemically polar polymers, it is necessary either to modify one or the other or to modify both polymers so as to avoid the separation of the layers in the multilayer pipes, or the so-called stratification. The modification is carried out by grafting a polar co-monomer, for example maleic anhydride. In this case, the content of the modified copolymer is from 15 to 35%.

The advantage of the thermoplastic composite and the pipes made of it, according to the described technical solution, consists in the reduction of the costs for the construction of pipe systems. This saving is achieved by reducing the CLTE of the pipes and, as a result, reducing the number of thermal expansion compensators in the pipe systems and the number of connecting fittings. Another advantage is, in the case of using polyvinyl alcohol and its copolymers with vinyl acetate, the reduction of the diffusion of oxygen through the wall of the pipe in the transported material (usually water).

Explanation of the attached figure

The technical solution will be explained in more detail by the attached figure 1, where a cross section of a multilayer pipe is shown.

Examples of implementation of the utility model

Thermoplastic composites preferably include composites based on polyvinyl alcohol and its copolymers with vinyl acetate with inorganic fillers and reinforcing components.

Fillers in the following text refer to inorganic or organic particles with approximately spherical symmetry, such as micronized calcium carbonate, wood flour or glass beads. The amounts commonly used for the reinforcing components listed below are intended to include inorganic or organic particles of approximately flat or fibrous shape, for example glass fibers, basalt fibers, carbon fibers, wollastonite, mica or talc. Again, unless explicitly stated otherwise, thermo-oxidation stabilizers, UV stabilizers, lubricants, colorants and dyes, anti-burn additives are considered as additives. , deacidifiers, dispersing agents for fillers and reinforcing components (e.g. graft copolymers and modified waxes), filler binders and / or reinforcing components of a thermoplastic matrix (e.g. silanes) and the like.

The samples in the form of tubes were measured in the direction of production of the tube, ie. in the longitudinal direction.

The measurement was performed on a standard version of a 15 μm test body made from a working part of an injected multifunctional test body stabilized in size by tempering for 7 days at 95 ° C. The DMA DXT04 (RMI CR) equipment used allows the measurement to be performed by placing the test body in a pressurized medium and applying a constant pressure of 4 kPa. During the temperature scan, the change Ah is measured at the initial height of the body h

The measurement conditions were selected after adjustment based on measurement experience as follows:

Heating to 95 ° C at a rate of 3 ° C / min, duration 20 min

Cooling to 20 ° C at a rate of 1 ° C / min, recording every 0.5 ° C, duration 20 min

Heating to 95 ° C at a rate of 1 ° C / min, no duration

Cooling to 20 ° C at a rate of 10 ° C / min, STOP

4338 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

In the course of temperature dependence Ah = h - h _Q is approximately equal to:

h = Βθ [1 + a (T - 23 ° C)]

The evaluation was performed during the first cooling of the sample as well as during the second heating. The values were compared and an average value was calculated for each material.

The changes in the length 1 of the test bodies depending on the temperature were measured. With these changes, the local coefficient of thermal expansion is calculated:

_1 & L ₌ 1 Ah h'cfT ~ h 'ΔΤ where the deviation calculation is substituted is a local line of coincidences is five consecutive corrected points. The calculations were performed both on cooling the first sample and on the second heating.

The values are compared and an average value is calculated for each material. Oxygen permeability is measured according to DIN 4726: 2008 in conjunction with ISO 17455: 2005. It is presented in units ps / t ² .dsn.

The examples below illustrate the characteristics of different multilayer pipes according to the technical solution.

Example 1.

As a basic thermoplastic matrix, any copolymer of propylene and ethylene with the following characteristics is used:

□ Melting index 0.25 (g / 10 min), (230 ° C, 2.16 kg), (ISO 1133), □ Ethylene content 5 wt. %, □ Density 902 kg / m ³ (ISO 1183 / A).

This plastic is modified by mixing in a melt 15 wt. % polypropylene is a modified polar co-monomer. In this case, the plastic exhibits the characteristics listed in Table 1.

Table 1: Characteristics of polypropylene modified with polar empoomer type 1

Characteristic Method Unit Value 1 Captain's Index [SO 1135 (g / y minutes), (230 ° C. 2.16 0.5 Output plastic - - Arbitrary copolymer of propylene with ethylene Modifying s- mopomer Anhydride of maleic acid Method of modification on squats monomer Grafted branches Content of | graft element Suitable method, 1-TIR weight % 2

4339 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

A polymer containing these structural units in the main linear chain (hereinafter referred to as PVOH) is also used in the production of the multilayer pipe:

• ethylene, • vinyl acetate, • vinyl alcohol.

Table 2: Characteristics of PVOH ionmeter 1

Харяктернстнка Method Unit Stoypn Cl Melting index ISO 1133 (g / 10 minutes), (190 ^q C, 2.16 tg). 4.4 Density [SO 1183- 3 kg / m ³ 11J0 Melting point (DSC) [SO 11357 ° C 183 Temperature Eta glazing (DSC) [SO 11357 ° C 60

A thermoplastic composite (designated PVONCOMP1) with 3 wt. % carbon fiber and with the parameters described in Table 3.

Table 3: Characteristics of ira cut in native fibers

Features Redness Surface treatment of tea Well not strong Slaughter diameter (pm) 7.2 Eia fiber length before mixing (mm) b Carbon content (% by weight) 95

From thermoplastic composites with 3 wt. % carbon fiber according to Table 3 and a made three-layer pipe with dimensions defined in Table 4. The cross section of this pipe is shown in Figure 1, where the thermoplastic composite is in only one layer 2.

Table 4: Dimensions of the three-layer pipe

Outer diameter (mm) 20 Inner diameter (mm) 12 Total wall thickness (tt) 4 Outer layer thickness - statistical copolymer of propylene and ethylene (III) 1.00 Thickness of the middle layer-comptpdit PVONCOMR 1 (mm) 2.00 DebeliEia on the upper layer - a statistical copolymer on propi.jch n egilen (pshg) 1.00

4340 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

The coefficient of linear thermal expansion (CLTE) was measured using the method described above, achieving the result a [10 ^_b / ° C] = 18.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of mg / m ² . day and reaches 0.22 mg / m ² . day.

Example 2.

The method of Example 1 is applied with the differences shown in Tables 5 and 6.

Table 5: Characteristics of propylene modified with polar co-monomer type 2.

Characteristic Method Ednnnid Сюйнмг INDEX HU CHAIRS ISO 1133 (g / 10 minutes), (230 'C, 2.16 kg), 4.5 Output plastic d Arbitrary copolymer of propylene is stylish Modifying co- monomer Anhydride of myaleinol acid Type of modification of the grafted co-monomsr - - Grafted branches Contents of graft element Suitable method, FTIR Ten. % 0.4

A thermoplastic composite with 15 wt. % ground carbon fiber with the parameters described in Table 6 and referred to below as PVOHKOMP2. As a binder, polypropylene with grafted maleic anhydride (characteristics in Table 5) was added to the unmodified polypropylene material (any copolymer of propylene and ethylene), as described above in Example 1, in a volume of 50 wt. %.

Table 6: Properties of ground carbon fibers

Features Stand fast Fiber surface treatment Amino silane Fiber diameter (mm) 7.4 Length of ND fibers spun blending (PCP) 0.2 Carbon content (test%) 98

A three-layer pipe with dimensions identical to those described in Table 4 was made. The cross-section of such a pipe is schematically shown in Figure 1, with PVOHKOMP2 representing the central layer 2, see Table 5.

The coefficient of linear thermal expansion (CLTE) was measured using the method described above, achieving the result a [10 ^_b / ° C] = 15.

4341 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of mg / m ² per day and reaches 0.42 mg / m ² . day.

Example 3.

The method described in Example 1 is applied, with the difference that a homopolymer of propylene with the following characteristics is used as a thermoplastic matrix:

□ melt index 0.30 (g / 10 min), (230 ° C, 2.16 kg), (ISO 1133), □ density 905 kg / m ³ (ISO 1183 / A).

Applying the method described above, the coefficient of linear thermal expansion (CLTE) was measured, and the result a [10 ^_b / ° C] = 32 was reached.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of mg / m ² . day and reaches 0.62 mg / m ² . day.

Example 4.

The method described in example 1 is applied, with the difference that a heterophase copolymer of propylene and ethylene with the following characteristics is used as a thermoplastic matrix:

□ Melting index 0.25 (g / 10 min), (230 ° C, 2.16 kg), (ISO 1133), □ ethylene content 7 wt. %, 900 density 900 kg / m ³ (ISO 1183 / A).

The plastic is modified by mixing in a melt of 3 5 wt. % polypropylene modified with a polar co-monomer.

Using the method described above, the coefficient of linear thermal expansion (CLTE) is measured, giving the result a [10 ^_b / ° C] = 46.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of mg / m ² . day and reaches 1.02 mg / m ² . day.

Example 5.

Any copolymer of propylene and ethylene with the following characteristics is used as the main thermoplastic matrix:

□ melt index 0.25 (g / 10 min), (230 ° C, 2.16 kg), (ISO 1133), □ ethylene content 5 wt. %, Ност density 902 kg / m ³ (ISO 1183 / A).

The material is used to make a multilayer pipe, as shown in Figure 1. The material forms layers 1 and 3.

A polymer containing these structural units in the main linear chain (hereinafter referred to as PVOH) was used in the production of the multilayer pipe:

• ethylene, • vinyl acetate, • vinyl alcohol.

Table 7: Characteristics of fuel cf PVOII2

Characteristic Mtrftn Unit Value Melted index ISO 1133 (glO minutes), (1U0 ⁱⁿ C, 2.16 tg), 1.6 Density JSO 1183- 3 kg / m ^J JJBt) Melting point (DSC) ISO 11357 183 Powder Point (DSC) ISO 11357 “S Jr.

4342 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

A thermoplastic composite (designated PVOHKOMP3) was prepared from PVOH with 10 wt. % carbon fiber with parameters defined in Table 8.

Table 8: Characteristics of PVOH composite (PVOHKOMP3) modified with polar co-monomer type 1 Характернсгнкл Method Unit Value Index ι m melt PVOH ISO 1133 (g / kg), (230 ⁰ C, 116 kg}, Modifying 1chastmas ПРОЙЛЙОЛСГ! etshoinmsr pa prltshlen with ethylene Content of modifying plastic π kpmpositd 35 Modifying symometer Hd anhydride madennoyltic acid Type of modification of the graft co-monomsr - - Grafted branches Content of graft ridge d in the modifying ILiaCl'MdCd Appropriate method. FTIR Tcui. % 10 Content of kugperold fibers (parameters in gaolia 3) Weight % 10

From the thermoplastic composite PVOHKOMP3 with 10 wt. % carbon fiber, as in Table 8, a three-layer pipe with dimensions defined in Table 9 is produced. The cross section of this pipe is schematically shown in Figure 1, the thermoplastic composite representing only one layer 2.

Table 9: Dimensions of the three-layer pipe according to example 5

Outer diameter (mm) 20 Inner diameter (mm) 12 Total sgspag thickness (εϊΙιϊΙ) 4 Thickness of the upper layer - a statistical salt polymer of propylene and = 1, (X)

4343 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

stylish (mm) Middle layer thickness - nmppoait FVOJIKQMFJ (ram) 2.0 (1 Thickness of the inner layer - a statistical copolymer of propylene and ethylene (III) 1.00

Using the method described above, the coefficient of linear thermal expansion (CLTE) was measured and a result of [10 ^_b / ° C] = 21 was obtained.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of §§ / t ² .dsn and reaches 0.72 ppm / t ² .dsn.

Example 6.

The method according to Example 5 was applied, except that ground carbon fibers were used, the characteristics of which are presented in Table 6.

From PVOH (see table) the thermoplastic composite (designated as PVOHKOMP4) with 10 wt. % carbon fiber with parameters defined in Table 10.

Table 10: Characteristics of PVOH composite (PVOHKOMP4) modified with polar co-monomer type 1 Characteristic Method Unit Value Index «a cioiiHjiKM PVOH ISO 1133 (g / ΊΟ minutes), (230 ° C, 2.16 kfi), 0.5 Modified plastic Random copolymer 113 propylene with stylish , Modified co-moomer Maleic acid anhydride Type of modification of the graft co-monomsr - - Grafted branches Content of the grafted element in the modifying plastic Suitable FTIR method Weight % 5 Carbon content (parameters in Table 6) Tetl. % 15

4344 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

From the thermoplastic composite PVOHKOMP4 with 10 wt. % carbon fiber, according to Table 5, a three-layer pipe with dimensions defined in Table 9 is made. The cross section of this pipe is schematically shown in Figure 1, where the thermoplastic composite is formed in only one layer 2.

Using the method described above, the coefficient of linear thermal expansion (CLTE) was measured and a result of [10 ^_6 / ° C] = 12 was obtained.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units ps / t ² .dsn and reaches 0.95 ppm / t ² .dsn.

Example 7.

The method of Example 5 was used except that a polypropylene homopolymer such as that described in Example 3 was used.

Applying the method described above, the coefficient of linear thermal expansion (CLTE) was measured, and the result a [10 ^_b / ° C] = 27 was reached.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of ppm / t ² .dsn and reaches 0.89 ppm / t ² .dsn.

Example 8.

The method of Example 5 was used except that a polypropylene heterophasic copolymer such as that described in Example 4 was used.

Using the method described above, the coefficient of linear thermal expansion (CLTE) was measured and a result of [10 ^_b / ° C] = 32 was obtained.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units ps / t ² .dsn and reaches 1.09 ps / t ² .dsn.

Example 9.

The method according to Example 5 was applied with the difference that a basalt fiber in a concentration of 7% was also used in the middle layer.

Applying the method described above, the coefficient of linear thermal expansion (CLTE) was measured, and the result a [10 ^_b / ° C] = 54 was reached.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of ppm / t ² .dsn and reaches 1.75 ^ppm: .dsn.

Example 10.

The method according to Example 6 was applied with the difference that a basalt fiber in a concentration of 7% was also used in the middle layer.

Applying the method described above, the coefficient of linear thermal expansion (CLTE) was measured, and the result a [10 ^_b / ° C] = 30 was reached.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of ppm / t ² .dsn and reaches 2.05 ppm / t ² .dsn.

Example 11.

The method according to Example 7 was applied with the difference that basalt fiber in a concentration of 9.9% was also used in the middle layer.

Using the method described above, the coefficient of linear thermal expansion (CLTE) was measured, and a result of [10 ^_6 / ° C] = 18 was reached.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units of ppm / t ² .dsn and reaches 1.09 ^ppm: .dsn.

Example 12.

The method according to Example 8 was applied with the difference that basalt fiber in a concentration of 9.9% was also used in the middle layer.

Applying the method described above, the coefficient of linear thermal expansion (CLTE) was measured, reaching α [10 ^_b / ° C] = 21.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units ps / t ² .dsn and reaches 1.19 ps / t ² .dsn.

4345 Descriptions to certificates for registration of utility models № 07.1 / 15.07.2019

Example 13.

Applied to the method according to Example 9 is the difference that a modifying agent is used in the middle layer as defined in Table 5 at a concentration of 35%.

Using the method described above, the coefficient of linear thermal expansion (CLTE) was measured and a result of [10 ^_b / ° C] = 38 was obtained.

Oxygen permeability is measured according to DIN 4726: 2008 in accordance with ISO 17455: 2005. It is expressed in units ps / t ² .dsn and reaches 2.09 ps / t ² .dsn.

Industrial applicability of the utility model

The technical solution finds application in the production of plastic pipes or other elements of polypropylene pipes or its copolymers. Ethylene has a reduced coefficient of linear thermal expansion and reduced oxygen permeability. It can also be used in the production of coextruded pipes used under pressure or without pressure. It can also be used in the production of boards or foils, mainly coextruded boards (two- or three-layer).

Claims (14)

Claims Thermoplastic composite of a copolymer of vinyl acetate and vinyl alcohol is ethylene and inorganic fillers and / or reinforcing components, characterized in that it contains 3-15 wt. % carbon fiber, from 0 to 9.9 basalt fiber and from 15 to 35 wt. % binders. Thermoplastic composite according to claim 1, characterized in that the carbon fiber is cut. Thermoplastic composite according to claim 1, characterized in that the carbon fiber is ground. Thermoplastic composite according to claims 1 or 2, characterized in that the binders are based on polypropylene and its copolymers are ethylene and polar co-monomers. Multilayer pipe comprising a thermoplastic composite according to claims 1 to 4, characterized in that at least one of its layers is made of a thermoplastic composite. Multilayer pipe comprising a thermoplastic composite according to claim 5, characterized in that the middle layer (2) is of a thermoplastic composite. Multilayer pipe comprising a thermoplastic composite according to claim 5, characterized in that a copolymer of propylene is ethylene is used for the inner layer (1) and the outer layer (3) of the pipe. Multilayer pipe comprising a thermoplastic composite according to claim 5, characterized in that a heterophasic copolymer of propylene and ethylene is used for the inner layer (1) and the outer layer (3) of the pipe. Multilayer pipe comprising a thermoplastic composite according to claim 5, characterized in that homopolymer polypropylene is used for the inner layer (1) and the outer layer (3) of the pipe. Multilayer pipe according to Claim 7, characterized in that a copolymer of propylene and ethylene is used for the inner layer (1) and the outer layer (3) of the pipe, and a graft polar number is modified. Multilayer pipe according to Claim 8, characterized in that a heterophasic copolymer of propylene and ethylene is used for the inner (1) and outer layer (3) of the pipe, and a graft polar co-monomer is modified. Multilayer pipe according to Claim 9, characterized in that a homopolymeric polypropylene is used for the inner layer (1) and the outer layer (3) of the pipe, and a graft polar co-monomer is modified. Multilayer pipe according to claims 10 to 12, characterized in that the grafted polar co-monomer is maleic anhydride. Multilayer pipe according to claims 10 to 13, characterized in that the content of the modified copolymer is from 15 to 35%.