阅读说明：本技术 用于制备可热成形的聚合物/纤维复合材料的方法 (Method for producing thermoformable polymer/fibre composites ) 是由 M·卡尔比 M·弗洛里 R·沙伊德豪尔 H·霍勒 于 2019-06-12 设计创作，主要内容包括：本发明涉及一种使用纤维基材、有机二异氰酸酯或多异氰酸酯化合物和分散体聚合物制备可热成形的聚合物/纤维复合材料的方法。(The present invention relates to a process for preparing a thermoformable polymer/fiber composite using a fibrous substrate, an organic diisocyanate or polyisocyanate compound and a dispersion polymer.)

1. A process for preparing thermoformable polymer/fibre composites using a fibrous substrate, an organic diisocyanate or polyisocyanate compound I and a polymer P, wherein

Introducing the fibrous substrate into a gas stream and then

Contacting the fibrous substrate in a gas stream with an aqueous dispersion of a polymer P having a glass transition temperature Tg and an organic diisocyanate or polyisocyanate compound I, and then

Drying the fibrous substrate which has been brought into contact with the aqueous dispersion of the polymer P and the organic diisocyanate or polyisocyanate compound I in a gas stream, followed by deposition and then

Converting the obtained deposited fibrous substrate into a fibrous web, after which

Consolidating the obtained fibrous web at a temperature of not less than Tg to obtain a thermoformable polymer/fibre composite,

the process comprises free-radically initiated emulsion polymerization of a mixture of ethylenically unsaturated monomers P [ monomer P ] in an aqueous medium in the presence of a polymer a to obtain an aqueous dispersion of polymer P, wherein polymer a is formed from the following components in copolymerized form:

a) 80% to 100% by weight of at least one ethylenically unsaturated monocarboxylic and/or dicarboxylic acid [ monomer A1], and

b)0 to 20% by weight of at least one further ethylenically unsaturated monomer different from monomer A1 [ monomer A2],

and wherein the type and amount of monomers P are selected such that the resulting polymer P has a glass transition temperature Tg ≥ 20 ℃ determined in accordance with DIN EN ISO 11357-2 (2013-09).

2. The process according to claim 1, wherein the weight ratio of polymer P to polymer A is ≥ 1 and ≤ 10.

3. The process according to claim 1 or 2, wherein the number-average molecular weight of the polymer A is not less than 1000 and not more than 30000 g/mol.

4. The process according to any one of claims 1 to 3, wherein the polymer P is prepared using:

not less than 90% by weight and not more than 99.9% by weight of styrene and/or methyl methacrylate,

not less than 0% by weight and not more than 9.9% by weight of n-butyl acrylate and/or 2-ethylhexyl acrylate, and

acrylic acid in an amount of not less than 0.1% by weight and not more than 10.0% by weight; methacrylic acid; glycidyl acrylate; glycidyl methacrylate; 2-hydroxyethyl, 2-hydroxypropyl and 3-hydroxypropyl acrylates and methacrylates; 2-aminoethyl, 2-aminopropyl and 3-aminopropyl esters of acrylic and methacrylic acid; 1, 4-butanediol diacrylate and 1, 4-butanediol dimethacrylate; 1, 2-divinylbenzene, 1, 3-divinylbenzene and 1, 4-divinylbenzene; allyl acrylate and/or allyl methacrylate,

wherein the amounts total 100 wt%.

5. The process according to any one of claims 1 to 4, wherein organic di-or polyisocyanate compound I is an aromatic di-or polyisocyanate compound.

6. The process according to any one of claims 1 to 5, wherein the organic di-or polyisocyanate compound I is diphenylmethane 2,2 '-diisocyanate (2,2' -MDI), diphenylmethane 2,4 '-diisocyanate (2,4' -MDI), diphenylmethane 4,4 '-diisocyanate (4,4' -MDI) and/or oligomeric diphenylmethane diisocyanate.

7. A method according to any one of claims 1 to 6, wherein the fibrous substrate used is natural fibres.

8. The process according to any one of claims 1 to 7, wherein the fibrous substrate is first contacted with the aqueous dispersion of the polymer P and then only with the organic di-or polyisocyanate compound I in the direction of the gas flow.

9. The process according to any one of claims 1 to 8, wherein the amount of polymer P is from 0.1 to 15% by weight and the amount of organic diisocyanate or polyisocyanate compound I is from 0.1 to 10% by weight, each based on the amount of fibrous substrate.

10. A process according to any one of claims 1 to 9, wherein the resulting thermoformable polymer/fibre composite is two-dimensional and has a basis weight of ≥ 500 and ≤ 30000g/m²。

11. A thermoformable polymer/fibre composite obtainable by the process of any of claims 1 to 10.

12. Use of a thermoformable polymer/fibre composite according to claim 11 for the preparation of a polymer/fibre moulding which differs in shape from the thermoformable polymer/fibre composite used.

13. A process for the preparation of a polymer/fibre moulding, which comprises heating a thermoformable polymer/fibre composite as claimed in claim 11 to a temperature of not less than Tg, converting the polymer/fibre composite thus obtained to a polymer/fibre moulding of the desired shape at a temperature of not less than Tg, and then cooling the resulting polymer/fibre moulding to a temperature of < Tg while retaining its shape.

14. A process for producing a polymer/fiber molding according to claim 13, wherein the operation of heating the polymer/fiber composite is carried out through a passage between two metal rolls arranged in parallel in the axial direction, the two metal rolls rotating in the direction of the passage, wherein

a) At least one of the metal rolls has a defined surface structure on the surface in contact with the polymer/fibre composite and a temperature ≧ Tg,

b) the gap between the contacting surfaces of the two metal rolls is less than the thickness of the polymer/fiber composite, an

c) The speed of passage of the polymer/fibre composite between the contact surfaces of the two metal rolls corresponds to the speed of rotation of the contact surfaces of the two metal rolls.

15. The method of claim 13 or 14, wherein a two-dimensional decorative material is applied to the polymer/fiber composite before or after the heating step.

16. A polymer/fibre moulding obtainable by the process according to any one of claims 13 to 15.

17. Use of the polymer/fibre moulding according to claim 16 as a floor covering, a furniture moulding or a wall trim part.

Examples

Preparation of an aqueous Polymer P1 Dispersion (Dispersion 1)

First, 36.5kg of deionized water were charged to a 500L pilot plant reactor equipped with a stirrer, reflux condenser and metering device under a nitrogen atmosphere at 20 to 25 ℃ (room temperature) and heated to 95 ℃ under stirring at atmospheric pressure (1.013 bar absolute). After this temperature had been reached, 14.0kg of a 7% by weight aqueous sodium persulfate solution were metered in continuously over the course of 10 minutes with stirring. Subsequently, the following were metered continuously into the reaction vessel, with stirring and while maintaining the above temperature, at constant flow rates, each starting at the same time: a mixture of 61.6kg of acrylic acid, 3.2kg of methyl methacrylate and 40.5kg of deionized water was added over 70 minutes, a mixture of 14.0kg of a 40% by weight aqueous sodium bisulfite solution and 1.4kg of deionized water was added over 70 minutes, and 32.5kg of a 7% by weight aqueous sodium persulfate solution was added over 75 minutes. Subsequently, the polymerization mixture was stirred for another 5 minutes and then cooled to 93 ℃. Thereafter, 13.9kg of 25% by weight sodium hydroxide solution are metered in over 10 minutes with stirring and the pH is thus established at 3.3, and then stirring is carried out for a further 5 minutes. Subsequently, feed 1 was metered in over 170 minutes, 48% by weight of feed 1 being initially charged over 20 minutes and 52% by weight of feed 1 being subsequently added over 150 minutes-each continuously at a constant flow rate. Feed 1 consisted of 21.8kg of a 7 wt% aqueous solution of sodium persulfate. 5 minutes after the start of feed 1, feed 2 was metered in continuously at a constant flow rate over 150 minutes while maintaining the polymerization temperature described above. Feed 2 consisted of 28.4kg of deionized water, 3.86kg of a 28 wt% aqueous solution of sodium lauryl ether sulfate ((II))FES 27; product from BASF SE), 2.88kg of a 15% by weight aqueous solution of sodium lauryl sulfate ((R)SDS 15; product from BASF SE), 4.54kg of glycidyl methacrylateEster, 1.06kg of 1, 4-butanediol diacrylate, 57.00g of methyl methacrylate, 86.48kg of styrene and 2.12kg of acrylic acid. After the addition of feed 1 was complete, stirring was continued for 10 minutes. Subsequently, 108g of antifoam (TEGO Foamex 822; product from Evonik Resource Efficiency GmbH) was added. Thereafter, the polymerization mixture was cooled to 90 ℃ and feeds 3 and 4 were continuously added at constant flow rate over 30 minutes, beginning simultaneously. Feed 3 consisted of 650g of a 10 wt% aqueous solution of tert-butyl hydroperoxide and feed 4 consisted of 820g of a 13.1 wt% aqueous solution of acetone bisulfite (the addition product of acetone and sodium bisulfite in 1:1 moles). After that, the obtained polymerization mixture was cooled to room temperature and filtered through a 125 μm filter. The resulting aqueous polymer dispersion had a solids content of 53.5% by weight. The number average particle size was determined to be 347nm and the glass transition temperature was determined to be 103 ℃.

The solids content is generally determined by drying 0.5 to 1g of the polymer dispersion or the resulting polymer solution to constant weight at 140 ℃ using a Mettler Toledo moisture analyzer.

The glass transition temperature is usually determined by means of a TA Instruments Q2000 differential calorimeter. The heating rate was 10K per minute.

The number average particle size of the dispersed particles is typically determined by dynamic light scattering at 23 ℃ from 0.005 to 0.01 wt% of the aqueous dispersion using an Autosizer IIC from Malvern Instruments, England. The cumulative z-average diameter of the measured autocorrelation function is recorded (ISO standard 13321).

The pH is typically determined by analyzing the sample at room temperature with a Schott pH electrode.

Performance testing

A study was conducted using a 12 inch refiner from Antriz and a blowpipe connected thereto. The refiner is operated at 160 to 170 ℃ and an internal pressure of 5 to 6 bar (gauge). The distance between the two grinding plates was 0.3mm, one of which was run at 3000 rpm. The inner diameter of the blow pipe (steel pipe) connected to the refiner by a flange was 3cm and the pipe length was 30 m. The aqueous polymer dispersion P was then injected into the blow pipe at 2 bar (gauge) through a 0.2mm nozzle located in the blow pipe at a distance of 50cm from the refiner outlet/blow pipe inlet, and the diisocyanate or polyisocyanate I was also injected into the blow pipe at 2 bar (gauge) through a 0.2mm nozzle located in the blow pipe at a distance of 80cm from the refiner outlet/blow pipe inlet. At the end of the blow pipe is a cyclone by means of which the coated wood fibres are further dried and cooled to a temperature of about 80c and deposited in an open container.

For these studies, spruce wood chips pretreated with water/steam at 160 to 170 ℃ at 5 to 6 bar (gauge) in a so-called boiler were used, wherein the mass flow rate of wood chips into the refiner (or wood fiber into the blow tube) was set at 30kg per hour.

The adhesive used was Dispersion 1 and the isocyanate used was a product from BASF Polyurethane GmbHM20R (PMDI), product from BASF Polyurethane GmbHMI (MDI), and from BASF Polyurethane GmbHMP 100/1, 40 wt% aqueous PMDI dispersion (E-PMDI), dispersion 1 used alone and in combination with the above-described diisocyanates and polyisocyanates. The adhesive is here injected into the blow pipe via a 0.2mm nozzle at a pressure of 2 bar (gauge) by means of an eccentric screw pump, wherein the mass flow rate is in each case adjusted to the respective amount of adhesive required per hour (calculated as solids). Each binder or binder combination was tested in a continuous steady state for 2 hours, during which the wood fibers sprayed with the respective binder in an open container were collected. In this way, the fiber/binder combination described in table 1 was prepared, the amounts being in parts by weight. It should be noted here that the quantitative data for dispersion 1 and E-PMDI are based on the respective solids content.

Table 1: prepared fiber/binder combination (in parts by weight)

Study of mechanical Properties

Coated fibers obtained from a blow tube according to the experimental procedure described above were used to prepare fibers having a thickness of 4.5mm and a density of 0.8g/cm³51X 51cm fiber board. For this purpose, 936g of the obtained fibers were uniformly dispersed in a horizontal wooden frame having an inner size of 51X 30cm (L/B/H). Thereafter, a 51X 51cm wooden board was placed horizontally on a fiber web present in a wooden frame and the fiber web was preliminarily compacted to a height of 10cm using a ram in the middle. The fiber block thus obtained was then taken out of the wood frame, covered with release paper on both square faces and compacted at 200 ℃ under pressure at a compression rate of 10 seconds/mm between two 10mm thick horizontal separating plates to a thickness of 4.5mm, wherein the lower face of the fiber block was in each case placed on the lower horizontal separating plate. The resulting fiberboard was then left outside the press to cool to room temperature.

Depending on the binder used, the fiber boards thus obtained were referred to as FVD1 (fiber board using dispersion 1), FVP1 (fiber board using PMDI), FVM1 (fiber board using MDI), FVE1 (fiber board using E-PMDI), FEP1 (fiber board using dispersion 1 and PMDI), FEM1 (fiber board using dispersion 1 and MDI) and FEE1 (fiber board using dispersion 1 and E-PMDI).

Compacting the fiber board for the second time to the density of 0.9g/m³The fiberboard was first stored in a climate controlled room at 23 ℃ and 50% relative humidity for one week. The fibreboard was then compressed in a heated press at 160 ℃ to a thickness of 4.0mm, corresponding to a density of 0.9g/cm, using an embossing plate in a contact press³And (d) engraving with sharp edges each having a stamping depth of 0.1 to 1.0mm in 60 seconds.

The water absorption and thickness swell of the fiber board obtained after this further compression were measured and the embossing was evaluated visually.

Here, the water absorption and thickness swelling were determined by punching corresponding 5x 5cm specimens from the fiber board, then accurately weighing and accurately determining the thickness. Subsequently, the samples were placed vertically in deionized water at 23 ℃ for 24 hours, then wiped dry with cotton cloth, then weighed, and the thickness of each sample was measured. Here, the water absorption (in wt%) was determined by multiplying the difference between the sample weights after and before water storage by 100, and dividing by the respective weights before water storage. In a corresponding manner, the thickness swell ratio was also determined by multiplying the difference between the sample thickness after and before water storage by 100, divided by the sample thickness before water storage. 5 samples were prepared from each fiberboard and used for testing. The test values reported below are the average of these 5 measurements. The lower the water absorption and the lower the thickness swell ratio, the better the evaluation of the water resistance. The results obtained for each sample are shown in table 2.

The embossing performance was evaluated by visually evaluating the embossed edges of each sample through a magnifying glass (having a magnification of 12 times) after water storage. The embossing performance was evaluated as good (+) when no protruding or loose fibers [ ═ roughness ] were visible at the embossed edges after water storage. In contrast, if the embossed edge after water storage had visible protruding or loose fibers, the embossing performance was evaluated as insufficient (-). When at least 4 of the 5 samples meet the above criteria, the specified evaluation is performed. The corresponding results are also shown in Table 2.

Table 2: results of samples after Water storage

The results clearly show that the sample consolidated using dispersion 1 alone does have good embossing properties but has high water absorption and high thickness swell, whereas the sample consolidated using only diisocyanate or polyisocyanate has low water absorption and low thickness swell but insufficient embossing properties. In contrast, samples cured using both dispersion 1 and either a diisocyanate or a polyisocyanate had good embossing performance and low water absorption, and the thickness swell ratio was low.