CS208146B2 - Method of making the objects from the filler and resinous amino-formaldehyde material - Google Patents

Abstract

1532626 Injecting filled resin articles BRITISH INDUSTRIAL PLASTICS Ltd 7 Nov 1975 [12 Nov 1974] Heading B5A Filled resin articles are made by injection moulding either a non-homogeneous mixture of dry amino-formaldehyde material with a filler or separate charges of the dry material and filler using a reciprocating screw injection device. The screw is effective to render the components of the working material into a homogeneous blend and the prior art necessity of forming a homogeneous blend before feeding to the injection device is obviated. The filler may be powdered, for example powdered cellulose, woodflour, talc, chalk or powdered glass or may be fibrous for example asbestos, carbon, glass or cellulose fibres. Preferred resins are methylated urea or melamine, alkylated derivatives of them, or urea, or melamine formaldehyde. Mixtures of these with unsaturated polyester resins can be used.

Description

The invention relates to a process for the manufacture of articles from a filler and from a resinous amino-formaldehyde material, both of which are in a non-fluid form, in a continuous shaping or extrusion sequence.

An essential feature of the production of the thermosetting molding compositions was the pre-kneading of the thermosetting resin material (used as the matrix) with the filler or fillers so that the filler was intimately mixed with the resin material, impregnated and coated therewith.

This can be done either under dry conditions where the resin material is substantially rigid and melts or softens during kneading, or in the presence of a solvent or other liquid medium, followed by optional drying. The resulting compression mixture is then processed in a separate step to cured articles by a compression or extrusion process.

U.S. Pat. No. 3,746,489 discloses a method of making glass fiber reinforced moldings by mixing the fibers with a liquid heat curable resin material to form a viscous pasty composition which is continuously fed in direct transport to an injector equipped with a nozzle to inject the mixture. into the mold cavity to react the mixture to form cured moldings.

The aim of this prior art manufacturing process is to facilitate the handling of glass fibers, to ensure their adequate dispersion in the resin material and to maintain their length so as to avoid significant loss of properties. For this purpose, a method of mixing fibers with resin material and an apparatus for carrying out this method have been proposed.

The yellowish mass fed directly from the mixer to the injection molding machine is essentially homole, well mixed mixture in the resin material, and the mixing operation of the injection molding machine must be minimized to prevent fiber degradation.

It has been found that it is possible to use injection molding machines or extruders to effect final mixing of coarse filler mixtures in thermosetting amino-formaldehyde resin materials and to produce molten articles directly from such masses without creating a homogeneous, well-mixed filler dispersion in prystyrene and without use. a specially designed mixer.

In a homogeneous dispersion, the filler (or reinforcing material) particles are well mixed with the sputtered and swollen or coated; In the non-homogeneous mixture of the kind used in the process according to the invention, the filler is not impregnated to a great extent impregnated or coated with the resin, but is only well mixed with it in an injection or extruder.

A method for producing articles from a filler and from a resinous amino-formaldehyde material, both of which are non-fluid in shape, in a continuous molding or extrusion sequence, is to form an inhomogeneous mixture of filler and solid particulate heat-curable ammonium-formaldehyde resin material capable of forming material, the non-homogeneous mixture is subjected to a rotating screw, and the material is pressed into the mold, whereby the mixture is subjected to a rotating screw. For example, when the inhomogeneous mixture is intimately mixed and plasticized to a homogeneous plastifcoovine mixture, curing is commenced with a mixture which is completed when the mixture is pressed into the mold.

The heat-meltable amine-foimaldehyde material may consist of a material capable of condensing to form a cured matrix (hereinafter referred to as a thermofusible material) in which any conventional additives, such as a catalyst, lubricant, stabilizer or plasticizer, may be dispersed, and they may be in granular or powder form.

In particular, the thermofusible may be a substantially solid product of the reaction between formaldehyde and a precursor selected from among the ureas, amino-ietriazines and phenols, e.g. or with another heat-meltable material, such as a composite condensate of an unsaturated polyester of solid melamine.

The heat-divisible material is in particular a mercury, mmlamine or phenol-formaldehyde resin, mixed or co-condensed with another heat-meltable material, such as alkyl, sintered, or the like. epoxy resin.

Heat-exchanged with material. in particular, it is a thermofusible resin which is partially condensed but substantially solid at ambient temperatures in the absence of dissolving solvents (an amount of water or other solvent).

If liquid plastics such as water or molybdenum glyceryl ether or other liquid components are used, they should be present in an amount such that the heat-meltable material is not liquid, preferably not even visibly moist.

In particular, at most about 10% by weight of the thermofusible material will be water or other solvent. Any volatile liquid initially usable in the inhomogeneous mixture is preferably vented from the drum during mixing. Because the resins used or produced in the drum are of the condensation type, water or other volatile matter may evolve during (although condensation that may occur under the effect of heat when the filler and the heat-sealable material are progressing through the drum. volatile matter, or can be either

208Т46 ben air ^. In (but not fully condensed at the outlet end of the drum, it is cast directly by direct injection into the mold (or by the so-called injection molding technique) or by directing it directly into the heated extrusion head and thereby curing.

The non-homogeneous mixture is preferably formed by coarse blending of the heat-cured mattrell with the filler and the resulting coarse mass is fed to the machine.

In another embodiment, the inhomogeneous mixture is formed in a hopper connected to the machine.

Preferably, the thermosetting compound and the filler are fed separately to the machine and the inhomogeneous mixture is formed at the inlet end of the machine drum.

According to another embodiment of the invention, the filler is selected from the group consisting of powdered cellulose, wood flour, slide, calcium carbonate, powdered glass, cured aninoplastic particulate materials, and fibrous macules.

The non-commercial mixture is conveniently formed at ambient temperatures.

According to another embodiment of the invention, the mold at the outlet end of the injection or extrusion drum is maintained at a temperature sufficient to initiate curing of the homogeneous fabric.

The injection or extruder may be provided with a single snake. It may be necessary to use machines equipped with a worm cover (drum) inside appropriately grooved depending on the particle size of the filler or the nature of the thermosetting material, in particular in a finely resembling form, to obtain the desired feed characteristics.

The aqueous fillers include cellulose, wood flour, talc, calcium carbonate (CaCO 3, powdered glass and the like) and cured special amniplectic masses.

The heatable materials can also be filled or reinforced according to the invention with fibrous materials such as cellulose, glass fibers, asbestos fibers or carbon fibers, and can include any suitable additives or manufacturing aids such as plasticizer, mold lubricant, curing agent or pigment .

In particular, the pigment may be added by coarse mixing with the thermosetting ether at the same time as the filler is added.

The following examples preferably illustrate embodiments of the invention.

Examples 1 and 2

The BIPEL 155/150 - (BIPEL is a registered trademark) injection molding machine was used with two modifications:

(a) Standard drum (the screw cover has been replaced by another with longitudinal grooving circumferentially spaced around the inner wall of the drum and extending over substantially the entire length of the drum; and

b) the feed container was equipped with a mixer to continuously mix its contents.

For both successive sieves (Table 1), all ingredients were filled into a paddle mixer before mixing was started, which was then carried out for 10 to 30 minutes to produce an inhomogeneous synthetic sieves, in this case a dried mixer. BL35 ammonium hydride resin, filler and other additives.

The coarse mixture thus produced was fed to the machine container and was put into operation to mix the contents in the container, bring it into the drum, join the non-heterogeneous mixture in the drum and make test pieces.

Table 1

Example

2.

Ingredients

Weighing parts

BL 35 Melminminmaldel resin 1 956.0 heat McGee ^(1> 148.5 curable taxámin ^) 14.9 mass Bmoksiee / b ^ 3) 55.6 lubricant 30.0 wood flour ‘ 1 000.0 (filler) BL 35 millinformaldehyde resin 2 220.0 heat glycerin mom otárová 10.8 curable lubricant 9.0 maatelál blue GLSR ⁽⁴⁾ 22.0 blue RS2 ⁽⁵⁾ 9.0 pigment ^black DC 70 ⁽⁶⁾ 1.5 whiteness ^of b ^and RH42 ⁽⁷⁾ 1.2 powdered cellulose 1 000.0 (filler)

Comment:

(1) mono-urea glycerine ether (2) hexaneethyentetramine (3) catalyst for the compression mixture, usually a mixture of zinc sulphite and finely ground melamine compression powder (4) Ciba Geigy (U.K.) Ltd.

(5) ReeHtts Colors Ltd.

(6) Blythe Colors Ltd.

(7) TiOg-Lapoote Indussries Ltd.

Table 2 shows the working conditions of the machine and the results notes.

Table 2

Drum temperature (° C)

Temperature Injection mold speed (° C) (s)

Injection pressure (MPa)

Snail Ryyciost (rpm)

Example 1

148

Example2 148

137.9

137.9 continued table

Reversible time (with) Screw Stroke (mm) Back pressure (MPa) Injection times (with) Cycle time (with) Comment Example 1 5 1.375 4.83 4 45 consistent moldings Example 2 6 1.375 4.83 25 125 good dispersion of pigm®ntu P Example 3 BL 35 Melaninhydraldehyde resin 2,220 parts heat hardenable lubricant 20 parts catalyst 3.2 parts pulverulent cellulose 900 parts filler BaSO ^ 100 parts

mass

Example

Heat-curable matt! as in Example 3, powdered cellulose glass fibers 3.18 mm

543

700

300 .2 parts parts parts filler

The urea hydride resin has a plaque catalyst catalyst cellulose

BaSO ^

400

1.4

4.76

133 parts parts parts parts parts parts heat-curable material

A 10: 1 molar ratio of hydroperhydride was produced.

resins by reaction of dimethyl urea and urea

Example

MelaIninomoVooinofvrmaldrhydviá rubber cinnamon stabilizer maaivo wood flour

600

070 parts parts parts parts thermosetting filler material

The melamine-formaldehyde resin was made by mixing the melamine-polymer-hydride resin with urea-polymer-hydride resin to form a plasticizer.

100 ALIGN!

200

165 parts parts parts parts

Example

A solid alkyd as contained in BEETLE 4 128 polyester resin (BEETLE is a registered trademark). 1,000 parts

BL 35 melamine-formaldehyde resins dialylphthalate tertiary butylperoxide silicone coupling agent lubricant powdered cellulose

CaCO ₃ Millicarb kaolin

000 parts heat-curable maatriél

100 parts parts parts parts

200 parts

000 parts filler

780 parts

^Alkyd: mmlaminformaldehydové resins and crosslinked to form a mixed resin system cured articles.

Example 8

BL 35 melamine-formaldehyde resin phenolic resin grease catalyst wood flour

400 parts

BaSO ^

700 parts parts parts

000 parts

150 parts heat-curable mattrial filler

Table 3

example 3 4 5 6 7 8 drum temperature ° C 95 95 90 90 50 100 ALIGN! mold temperature ° C 165 165 150 150 165 165 Injection pressure (MPa) 12.07 12.07 12.07 12.07 12.07 12.07 p ^ lk ^ e ^ Rising pressure (№ »a) 4.83 4.83 4.83 4.83 4.83 4.83 injection time (s) 10 10 10 10 10 10 total cycle time (s) 40 40 20 May 20 May 40 40

Table 4

property in the example 3 4 5 6 7 8 ewnost ^P in bending (MN./m ²⁾ 77 66 87 95 48 84 module ^p ružnooti ⁽ GN / m ²⁾ 4.8 6.0 4.8 5.5 4,5 5.4 energy at fracture ⁽ KJ / m ²⁾ 618 363 788 820 256 654 fracture deviation (mm) 1.6 b ' 1,8 1.7 1.1 1.6 Boiling water absorption (mg / g) 22nd 23 25 50 10 17 ^ o ^ ^d of CNI ponr ® G0 ^one of ^EMU) 1.3 3.3 2.7 1.6 4.3 4.0

In each of Examples 3 to 8, the moldings produced were pin-shaped. These showed acceptable surface finish, mechanical strength and physical properties. .

The operating conditions of the injection (or extrusion) press can be readily selected by appropriately qualified personnel. For machines of the general type used as described above, the following advantageous conditions are:

Drum temperature 80-110 ° C. Mold temperature 140-170 ° C. Injection pressure up to 137.9 MPa. Total cycle time 15 to 130 seconds.

These conditions may vary at will depending on the materials used and the type of moldings to be produced. The extruder will be provided with an extrusion head that can be heated to a temperature high enough to cure the mass passing therethrough.

Previously, it was necessary for industrial forms to require manufacturers of molding compositions containing the appropriate amount and type of filler for special applications. In turn, it has often been necessary for the molding compound manufacturers to maintain stores of different molding compositions based on the same resin material but containing different amounts and / or types of homogeneously dispersed filler. There is often a need for better storage of stocks.

By means of the invention, the manufacturers of molding compounds can now produce only unfilled or partially filled synthetic, thermosetting compositions for industrial forms, which can then coarse mix them with the required amount and type of filler to form an inhomogeneous mixture without excessive labor and overhead costs. mention.

Claims (7)

SUBJECT OF THE INVENTION A method for producing articles from a filler and from an amine-formaldehyde resin material, both of which are in a non-fluid form, in a continuous molding or extrusion sequence, characterized in that a non-homogeneous mixture of filler and solid particulate thermally curable amino-aminofortnaldehyde resin material curable to form a solid plastic material, the inhomogeneous mixture is subjected to a rotating screw and the material is pressed into a mold, where the inhomogeneous mixture is thoroughly mixed and plasticized to a plasticized homogeneous mixture, curing of the mixture is started and finished at 130-180 ° C when the mixture has been pressed into the mold. 2. The method of item 1, wherein the thermosetting material consists of a thermosetting component and additional components, wherein the thermosetting component consists of a substantially solid reaction product between formaldehyde and a precursor selected from ureas, amino-s-triazines. and phenols, from a derivative of such a product or from a mixture or associated condensate of such a product or derivative 8 with another such product or another heat-curable substance. 3. A method according to claim 1 or 2, characterized in that the inhomogeneous mixture is formed by coarse heat-mixing of the curable material with the filler and the resulting coarse mass is fed to the machine. Method according to claim 1 or 2, characterized in that the inhomogeneous mixture is formed in a hopper connected to the machine. Method according to claim 1 or 2, characterized in that the heat-curable material and the filler are fed separately to the machine and the inhomogeneous mixture is formed at the inlet end of the machine drum. 6. A method according to any one of the preceding claims 1 to 4 wherein the filler is selected from the group consisting of powdered cellulose, wood flour, slip, calcium carbonate, powdered glass, cured aminoplastic particulate materials and fibrous materials. 7. A method according to any one of the preceding claims 1 to 6, wherein the non-homogeneous mixture is formed at ambient temperatures.