CN110760181A

CN110760181A - Thermoplastic prepreg slurry based on slurry method and preparation method

Info

Publication number: CN110760181A
Application number: CN201910920762.6A
Authority: CN
Inventors: 鲁平才; 薛胜; 张凤翻; 鲁兆鋆
Original assignee: Jiangsu Zhao Lam Novel Material Limited-Liability Co
Current assignee: Jiangsu Zhao Lam Novel Material Limited-Liability Co
Priority date: 2019-09-27
Filing date: 2019-09-27
Publication date: 2020-02-07

Abstract

The invention discloses a thermoplastic prepreg slurry based on a mud method and a preparation method thereof. The slurry comprises the following components in percentage by mass: 1-50% of thermoplastic resin; 50-95% of water; 0.1-10% of water-soluble polymer; 0.01 to 5 percent of surfactant; 0.1-10% of viscosity reducer. The invention also discloses a preparation method of the slurry. According to the invention, by selecting proper types and dosage of water-soluble polymers, the viscosity of the system is increased, the stability of the resin powder in water is improved, the binding power of the resin powder and fibers is increased, and meanwhile, a viscosity reducer is used in a matching manner, so that the viscosity of the slurry system is adjusted, the stability of the slurry is improved, the concentration control of the resin slurry is facilitated, the continuous production of the prepreg is realized, and on the other hand, the impregnation effect can be ensured, and the balance between the stability and the impregnation effect is realized.

Description

Thermoplastic prepreg slurry based on slurry method and preparation method

Technical Field

The invention relates to prepreg slurry, in particular to thermoplastic prepreg slurry based on a mud method and a preparation method thereof.

Background

With the requirements of energy conservation, emission reduction and light weight, the application of the thermoplastic resin matrix composite material in the fields of automobiles, aerospace and the like is continuously developed, and the continuous fiber reinforced thermoplastic composite material gradually receives attention. The thermoplastic resin has the advantages of high heat resistance, high toughness, low water absorption and the like. At room temperature, most of the thermoplastic resin is in a solid particle state; in a molten state, the resin melt has high viscosity, the melt is difficult to flow, and the impregnation effect with the fiber is poor. The superfine resin powder is uniformly soaked and dispersed into the fiber bundle by a mud method, and the resin is fully soaked in the fiber by heating.

The core of the mud method for preparing the thermoplastic composite material is resin powder slurry. Generally, the slurry takes water as a dispersion medium, the boiling point of the water is relatively low, the water is easy to remove from the slurry, the source is wide, and the environment is not polluted. However, the compatibility of the resin powder with water is poor, and the long-term stable and uniform dispersion is difficult to realize through mechanical and ultrasonic action. When the resin powder floats upwards or settles, the stability of the concentration of the slurry is damaged, the continuous production is not facilitated, and the phenomenon of uneven resin content of the prepreg occurs.

The slurry is required to have good stability when the prepreg is prepared by the slurry method. On one hand, good stability requires that the resin powder can be stably suspended and dispersed in water for a long time, so that the fibers can uniformly adsorb the resin slurry; on the other hand, the good stability is convenient for the real-time on-line monitoring of the powder content of the resin sizing agent, and the stable and continuous production of the prepreg is ensured.

Disclosure of Invention

In order to solve the problem of poor stability of the thermoplastic resin powder slurry, the invention provides a slurry method-based thermoplastic prepreg slurry and a preparation method thereof, which can stably disperse resin powder in a system for a long time.

The invention relates to a thermoplastic prepreg slurry based on a slurry method, which comprises the following components in percentage by mass:

wherein the mass percent of the thermoplastic resin and the water is the proportion of the total amount of the thermoplastic resin and the water,

the mass percentages of the water-soluble polymer, the surfactant and the viscosity reducer are in the ratio of the total amount of the thermoplastic resin and the water.

The thermoplastic resin as the base resin of the paste has the following requirements:

(1) the density of the thermoplastic resin needs to be > 1g/cm³(ii) a The maximum density of the thermoplastic resin is generally 1.5g/cm³On the other hand, therefore, the upper limit of the density is not limited herein as long as > 1g/cm is satisfied³；

(2) The thermoplastic resin used needs to be crushed and ground, the average powder particle size (D50) needs to be less than 50um, preferably less than or equal to 5um, and the smaller the powder particle size, the easier the powder particle size is to be impregnated into the cellulose;

(3) melt flow rate: 40-700g/10min, good fluidity ensures that the resin can better impregnate fibers in a molten state, and material performance needs to be considered at the same time, the better the melt fluidity, the shorter the polymer molecular chain, and the lower the material performance.

Further, the thermoplastic resin is selected from one or more of thermoplastic plastics such as nylon (PA), Polycarbonate (PC), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), and polyether imide (PEI).

The water is generally deionized water, is used as a slurry dispersion medium, and can be added with part of ethanol or methanol to enhance the powder dispersing ability and help the water volatilization.

Water-soluble polymers are used as binders and thickeners. By selecting proper type and dosage of the water-soluble polymer, the viscosity of the system is increased, the stability of the resin powder in water is improved, and the binding force of the resin powder and the fiber is increased. Preferably, the water-soluble polymer is selected from one or more of nonionic water-soluble cellulose, nonionic water-soluble hydroxypropyl methyl cellulose, polyvinylpyrrolidone and polyvinyl alcohol.

When the water-soluble polymer is used, deionized water with the temperature of 40-100 ℃ is used for dissolving under the condition of mechanical rapid stirring so as to prevent the water-soluble polymer from agglomerating and accelerate the dissolution. Ethanol can also be used as a dispersion aid, and the aqueous polymer is added into the ethanol, mechanically dispersed to form a suspension, and then dripped into water to be dissolved.

Viscosity reducing agent: is selected from one or more of C2-C10 alcohol. The viscosity of the slurry system is changed by matching with a water-soluble polymer, and the viscosity of the slurry is controlled within 0.1-50 cps. When the viscosity of the slurry is lower, the slurry is easy to impregnate but the system stability is poorer, and on the contrary, the system viscosity is higher, the stability is obviously improved but the liquid is difficult to impregnate into the fiber bundles. The viscosity of the slurry is changed by adding the viscosity reducer, so that the stability and the impregnating capacity of the system are optimal. Further, the viscosity reducer is selected from one or more of 1, 3-butanediol, n-octanol and ethylene glycol.

The surfactant can improve the compatibility of the thermoplastic resin powder with water. Preferably, the surfactant is selected from one or more of Fluorad 430, Fluorad 431, octadecyl benzyl dimethyl ammonium chloride and castor oil polyethylene oxide ether.

Preferably, the slurry composition comprises, in mass percent:

further preferably, the slurry composition comprises, in mass percent:

preferably, the slurry of the thermoplastic prepreg based on the slurry method further comprises one or more of a bactericide, a plasticizer and an anti-foaming agent.

The aqueous slurry is easy to generate mould and generate peculiar smell after long-term use, and can be sterilized by adopting a bactericide. Preferably, the bactericide is selected from one or more of ROCAMA 361, polypase 689, Nordes C15, Nordes KC30, Nordes B100, Nordes DHF and Nordes QK 20.

The plasticizer improves the toughness of the thermoplastic prepreg, particularly polyphenylene sulfide, the toughness of the thermoplastic prepreg is poor, and the prepared prepreg is easy to crack. Preferably, the plasticizer is selected from one or more of propylene glycol, ethylene glycol glyceride, nitrile rubber, core-shell nanoparticles, nylon and polycarbonate.

The antifoaming agent is used as an antifoaming agent for a surfactant. The measurement of the actual viscosity of the slurry is affected by the presence of more air bubbles in the slurry. The anti-foaming agent is a siloxane compound, and is specifically selected from one or more of polydimethylsiloxane, octamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, dimethylcyclosiloxane and the like.

The mass percentage of the bactericide in the slurry is 0.01-5%, the mass percentage of the plasticizer in the slurry is 0.01-20%, and the mass percentage of the anti-foaming agent in the slurry is 0.01-5%. Preferably, the bactericide accounts for 0.01-2.5% by mass, the plasticizer accounts for 1-10% by mass, and the anti-foaming agent accounts for 0.03-2% by mass. More preferably, the bactericide accounts for 0.2-2% by mass, the plasticizer accounts for 5-7% by mass, and the anti-foaming agent accounts for 0.1-0.3% by mass.

In preparing the thermoplastic prepreg, the fibers or fabrics may be selected from fabrics or fibers conventionally selected in the art, for example, fibers the slurry of the present invention is suitable for sizing agent-free carbon fibers, thermoplastic sizing agent-treated carbon fibers, silane coupling agent-treated glass fibers, and the like.

The preparation method of the slurry comprises the following steps: dispersing other additives except the waterborne polymer into water, independently dissolving the waterborne polymer into the water, then adding the water-soluble polymer into other additive systems, finally adding the resin powder into the additive systems, and uniformly stirring.

The viscosity of the slurry is 0.1 to 50cps, preferably 2 to 5 cps.

Specifically, the preparation method of the slurry comprises the following steps:

(1) weighing a proper amount of water, surfactant, anti-foaming agent, bactericide, plasticizer and viscosity reducer, starting mechanical stirring, and stirring at the rotating speed of 400-.

(2) Dissolving the aqueous polymer, using deionized water with the temperature of 40-100 ℃, separately stirring and dissolving, slowly adding the dissolved aqueous polymer into the mixture obtained in the step (1), and stirring for at least 30min to uniformly stir all the auxiliary agents. The water-soluble polymer has slow dissolution speed in water, is easy to agglomerate to form blocks after contacting with water, is not easy to dissolve in water, and is found to be dissolved in advance according to a plurality of tests. In addition, the addition of the resin powder first and then the addition of the aqueous polymer, since the resin itself is poor in compatibility with water, cannot achieve a dispersing effect by stirring the resin powder added in advance.

(3) The resin powder was slowly added to (2) in portions to thoroughly mix the powder with water. The stirring time is at least 6 hours, and multiple viscosity test comparisons show that the mixed slurry is stirred at a high speed for more than 6 hours, and the fluctuation range of the slurry viscosity is small.

Has the advantages that:

according to the invention, by selecting proper types and dosage of water-soluble polymers, the viscosity of the system is increased, the stability of the resin powder in water is improved, the binding power of the resin powder and fibers is increased, and meanwhile, a viscosity reducer is used in a matching manner, so that the viscosity of the slurry system is adjusted, the stability of the slurry is improved, the concentration control of the resin slurry is facilitated, the continuous production of the prepreg is realized, and on the other hand, the impregnation effect can be ensured, and the balance between the stability and the impregnation effect is realized.

The stability of the slurry can be further improved by further optimizing the resin or other auxiliary agents.

The aid scheme of the invention is applicable to most thermoplastic resins, provided that the resin density is greater than 1g/cm³. Melt impregnation of the resin into the fiber bundle is facilitated by the selection of the resin flow rate and the powder particle size.

According to the invention, less auxiliary agent is added, the stability of the slurry is improved, the problem that the resin powder cannot be stably dispersed in water for a long time is solved, and the stability of the continuous production by a mud method is ensured.

By the bactericide, the generation of bacteria or odor during long-time storage or use of the resin slurry using water as a dispersant is avoided.

Drawings

FIG. 1 is a graph of the stability results for various formulations of example 1;

figure 2 is a graph of the stability results for different formulations of example 1.

Detailed Description

Example 1

The slurry formulation is shown in table 1:

TABLE 1

Note: in the table, the resin powder and deionized water were mixed as 100 parts (100%), and the other additives were individually calculated because of their small addition amount. All adjuvants are present in a percentage based on the total amount of resin and deionized water, e.g., 0.7% water-soluble polymer (weight of resin powder and deionized water).

The preparation method of the slurry comprises the following steps:

experimental group (a)

(1) 65kg of deionized water, 0.2kg of surfactant, 0.3kg of anti-foaming agent, 0.2kg of bactericide, 7kg of plasticizer and 1.2kg of viscosity reducer are weighed and added into a dispersing barrel, mechanical stirring is started, and the stirring speed is 700 r/min.

Surfactant (b): castor oil polyethylene oxide ether (i.e. castor oil polyoxyethylene ether) anti-foaming agent: polydimethylsiloxane; and (3) bactericide: water paint bactericide Nordes QK 20; plasticizer: propylene glycol; viscosity reducing agent: 1, 3-butanediol and n-octanol are mixed according to the mass ratio of 7: 3.

(2) Dissolving a water-based polymer polyvinyl alcohol PVA1799, using 10kg of deionized water with the temperature of 60 ℃, and separately stirring for dissolving; after the dissolution is finished, slowly adding the mixture into the mixture in the step (1), and stirring for 60min to ensure that the auxiliary agents of all parts are uniformly stirred.

(3) 25kg of nylon 6 powder was slowly added to (2) in portions to thoroughly mix the powder with the other system components, and the stirring time was 12 hours.

Experimental group (b)

(1) 75kg of deionized water, 0.2kg of surfactant, 0.3kg of anti-foaming agent, 0.2kg of bactericide and 7kg of plasticizer are weighed and added into a dispersing barrel, mechanical stirring is started, the stirring speed is 700r/min, and the stirring time is 60 min.

Surfactant (b): castor oil polyethylene oxide ether; anti-foaming agent: polydimethylsiloxane; and (3) bactericide: the water paint bactericide Nordes QK 20.

(2) 25kg of nylon 6 powder is slowly added into the mixture in the step (1) in batches, so that the powder and other components of the system are fully mixed, and the stirring time is 12 hours.

Experimental group (c)

(1) 85kg of deionized water, 0.2kg of surfactant, 0.3kg of anti-foaming agent, 0.2kg of bactericide, 7kg of plasticizer and 1.2kg of viscosity reducer are weighed and added into a dispersing barrel, mechanical stirring is started, and the stirring speed is 700 r/min.

Surfactant (b): castor oil polyethylene oxide ether; anti-foaming agent: polydimethylsiloxane; and (3) bactericide: water paint bactericide Nordes QK 20; plasticizer: propylene glycol; viscosity reducing agent: the mixture of 1, 3-butanediol and n-octanol is 7:3 (mass ratio).

(2) The aqueous polymer polyvinyl alcohol PVA1799 was dissolved using 10kg of deionized water at 60 ℃ with separate stirring. After the dissolution is finished, slowly adding the mixture into the mixture in the step (1), and stirring for 60min to ensure that the auxiliary agents of all parts are uniformly stirred.

(3) 5kg of nylon 6 powder was slowly added to (2) in portions, the powder was thoroughly mixed with water, and the stirring time was 12 hours.

Experimental group (d)

(1) 60kg of deionized water, 0.2kg of surfactant, 0.3kg of anti-foaming agent, 0.2kg of bactericide, 7kg of plasticizer and 1.2kg of viscosity reducer are weighed and added into a dispersing barrel, mechanical stirring is started, and the stirring speed is 700 r/min.

(3) And (3) slowly adding 30kg of nylon 6 powder into the mixture in the step (2) in batches, fully mixing the powder with other components of the system, and stirring for 12 hours.

Experimental group (e)

(1) 65kg of deionized water, 0.05kg of surfactant, 0.15kg of anti-foaming agent, 0.2kg of bactericide, 7kg of plasticizer and 0.8kg of viscosity reducer are weighed and added into a dispersing barrel, mechanical stirring is started, and the stirring speed is 700 r/min.

(3) 25kg of nylon 6 powder is slowly added into the mixture in the step (2) in batches, so that the powder and other components of the system are fully mixed, and the stirring time is 12 hours.

Experimental group (f)

The preparation steps are as in experimental group (a), and the types of the auxiliary agents are replaced.

Surfactant (b): octadecyl benzyl dimethyl ammonium chloride; anti-foaming agent: octamethylcyclopentasiloxane; aqueous polymer: nonionic water-soluble cellulose (aqueous, ashland hydroxyethylcellulose thickener NATROSOL PLUS, usa); the rest is unchanged.

And (3) carrying out stability test on the slurry prepared from the above groups, wherein the slurry stability test method comprises the following steps: adding the mixed slurry of the same batch into 3 measuring cylinders of 100ml respectively, horizontally standing, and recording the condition of slurry layering and descending at regular intervals. And judging the stability of the slurry according to the layering speed of the slurry.

Stability tests were performed on samples taken from the above experimental groups (a), (b), (c) and (d). The results are shown in FIG. 1. The experimental group (b) is a blank control with respect to the experimental group (a). The stability of the resin slurry under a standing condition can be obviously and effectively improved by adding the water-based polymer and the viscosity reducer. Under the same auxiliary agent conditions (a), (c) and (d), the stability of the slurry under a standing condition is influenced by the content of the solid powder, and the more the solid content is, the more the sedimentation and the delamination are relatively easy.

The experimental groups (a), (e) and (f) were sampled and subjected to stability analysis. The results are shown in fig. 2, under the same resin slurry concentration, the influence of the amount and the type of the auxiliary agent on the slurry stability is remarkable, the experimental group (a) has better stability within 45min, and the experimental group (f) has better stability performance for a long time (> 45 min). . One of the important indexes of the quality of the prepreg product is the content and the thickness of prepreg resin, and although the influence factors of the content and the thickness of the prepreg resin are more and can be adjusted to a certain extent through equipment and process control, the important function of the formula of the sizing agent is self-evident. In the actual production process, the optimal formula is required to realize the long-time stability of the slurry, so that the uniform content of the prepared prepreg resin can be ensured. Although the invention mainly improves the stability by the combination of the waterborne polymer and the viscosity reducer, the research shows that the type and the content of the resin and other auxiliary agents have more or less influence on the stability of the system.

The impregnation effect is compared by observation, on one hand, after the fiber is dried, the fiber bundle is opened to see whether the intermediate powder is lacked; on the other hand, the size does not impregnate the fibres, and there is dry yarn in the breaks from the prepreg processed by the mould or cracks during production. After the prepreg is used for a period of continuous production, the resin impregnation effect in the prepreg is in the following order from good to poor: a/f > d/e > b/c. b/c two groups of fiber bundles have less resin powder adhesion, and the phenomenon of yarn drying exists. The a/f two groups have relatively good resin melting and impregnating effects, no obvious dry yarn and sufficient powder content in the fiber bundles.

Claims

1. A thermoplastic prepreg slurry based on a slurry method is characterized in that the slurry comprises the following components in percentage by mass:

2. The thermoplastic prepreg slurry based on the mud process according to claim 1, wherein the water-soluble polymer is selected from one or more of non-ionic water-soluble cellulose, non-ionic water-soluble hydroxypropyl methylcellulose, polyvinylpyrrolidone, and polyvinyl alcohol.

3. The slurry process based thermoplastic prepreg slurry according to claim 1, wherein the viscosity reducing agent is selected from one or more of the series 1, 3-butanediol, n-octanol, ethylene glycol.

4. The thermoplastic prepreg slurry based on the slurry process according to claim 1, wherein the surfactant is one or more selected from the group consisting of Fluorad 430, Fluorad 431, octadecyl benzyl dimethyl ammonium chloride, and castor oil polyethylene oxide ether.

5. The mud process-based thermoplastic prepreg slurry of claim 1, wherein the thermoplastic resin density is greater than 1g/cm³Particle size less than 50um, melt flow rate: 40-700g/10 min.

6. The thermoplastic prepreg slurry based on the slurry process according to claim 1, wherein the slurry viscosity is 0.1 to 50 cps.

7. The mud process-based thermoplastic prepreg slurry according to claim 1, wherein the slurry composition comprises, in mass percent:

8. the thermoplastic prepreg slurry based on the slurry process according to claim 1, wherein the slurry further comprises one or more of a bactericide, a plasticizer and an antifoaming agent.

9. The thermoplastic prepreg slurry based on the slurry method according to claim 8, wherein the mass percent of the bactericide is 0.01 to 5%, the mass percent of the plasticizer is 0.01 to 20%, and the mass percent of the anti-foaming agent is 0.01 to 5%, based on the total amount of the thermoplastic resin and the water in the slurry.

10. The method of mud process based formulation of thermoplastic prepreg slurry according to claim 1, comprising: dispersing other additives except the waterborne polymer into water, independently dissolving the waterborne polymer into the water, then adding the water-soluble polymer into other additive systems, finally adding the resin powder into the additive systems, and uniformly stirring.