JPS5831198A - Production of light weight molding material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a lightweight molding material having a low bulk specific gravity and good heat formability.

Conventionally, 5kJJ (felt-like molding material made of fibrous material bound with a binder such as emulsion) has been used for interior materials of automobiles, insulation materials for folded roofs, etc. simply mixing the fibrous material and the binder in a dispersion medium;
There is a method in which this material is made into 7-elt by papermaking, and in the process of papermaking, it becomes a heavy material containing multiple layers of media, resulting in a molding material with low bulk and high specific gravity.
Furthermore, the fibrous materials are arranged in a plane and are easy to tear into layers in the thickness direction, and the efficiency of using the binder is poor, and the concentration of the w & fibrous binder in the dispersion medium changes from moment to moment. It had drawbacks such as not being able to be used repeatedly. Also, if the softening temperature of the binder is high, the moldability will be poor, and conversely, the softening temperature will be high.
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6 In view of the above-mentioned drawbacks, the present invention aims to provide a method for suitably producing a lightweight molding material in which fibrous materials are well intertwined with each other, have a small bulk specific gravity, have excellent heat formability, and have excellent VC heat resistance. This was done in conjunction with point 1, and its gist is that fibrous materials and resins have different glass transition temperatures, and two or more types of thermoplastics in which the resins are incompatible with each other! There is a method for producing a lightweight molding material, which is characterized by mixing an M fat emulsion in water and foaming it, causing the fibrous thermoplastic resin to float together with the foam to form a scum 1-1.

Examples of the fibrous material used in the present invention include inorganic fibers such as glass fiber, carbon fiber, rock cool, asbestos, ceramic fiber, and artificial crystal fiber, polyamide,
polyethylene terephthalate, polyacrylonitrile,
Examples include synthetic fibers such as polyvinylidene chloride and polyvinyl alcohol acetal, cotton, hemp, silk, pulp, raw wool, wool, pig hair, horse hair, etc., and vegetable fibers such as cotton, linen, and cotton are molded. In order to reduce the weight of the material, [ is preferably used, and is a particularly preferred pulp. In addition, when using the above-mentioned vegetable fibers, if the content of the fibers in the molding material increases, the heat formability will decrease, and if the content decreases, the thermal dimensional stability will be impaired. It is preferable that the content be %.

Misfired Ql-I K The thermal 0f plastic resin 11Fj emulsion used is two or more types in which the glass transition temperatures of the resins are different and the 1b1 resins are not mutually compatible.
The glass transition temperature of the resin is I 06°C or higher and 50°C.
The following are preferably used: These thermoplastic 1mF+ emulsions are well-known as 3 types, and can be appropriately selected from the following. - I can do it. (possible 11
Examples of thermoplastic resin emulsions having a glass transition temperature of 1'1 of 100°C or higher include polystyrene, styrene-acrylonitrile copolymer, and polymethyl methacrylate.
The emulsion of /-to etc. is opened and! For example, polyvinyl acetate, ethylene-vinyl acetate copolymer (for example, polyvinyl acetate, ethylene-vinyl acetate copolymer)
x Mulsion can be given. and a thermoplastic resin emulsion whose glass transition temperature is 100°C or higher and 50°C.
The following combination of thermoplastic 48111j emulsions is preferably a combination of styrene-acrylonitrile emulsion and vinyl acetate emulsion, and the ratio of the two is 41
- means that as the proportion of thermoplastic resin emulsion with a glass transition temperature of 100°C or higher increases, the heat formability decreases, and conversely, as the proportion decreases, the heat resistance decreases, so the glass
The ratio of the thermoplastic resin emulsion having a temperature of 00'C or higher to the thermoplastic resin emulsion having a glass transition temperature of 50C or lower is preferably 1:1 to 3:1.

In the present invention, the fibrous material and the resin have different glass transition temperatures, and two or more resins are incompatible with each other.
A thermoplastic resin emulsion is mixed and foamed in water,
The fibrous material and thermoplastic resin are floated together with foam to form a scum, and in order to improve foaming properties during mixing, alkylglycine, alkylbetaine, alkylimidacillin, polyglycolamine sulfate,
Surfactants such as alkylamine sulfonic acids may also be added.

When mixed and foamed as described above, the foam rises together with the fibrous material and the thermoplastic resin, and the fibrous material is evenly distributed in the foam. Equally 11 three-dimensionally fibrous and 1
A scum in which the sjk i'J' plastic resin is distributed is formed, and this scum is then milled and dried.

Fibers in the scum that was extracted with foam
:11, due to the presence of H・1 droplets, it is deposited in layers.
-They are completely intertwined in three-dimensional directions, and
The thermoplastic resin is also uniformly dispersed, so after it dries and the foam disappears, the fibrous material bonded by the thermoplastic FA resin can be cut into a bulky light molding material.

4/ as a fibrous material! When manufactured as described above using 4-absorbent fibers, a product with a density of 0.5V/7 or less can be obtained, but if the density is less than (LO57/-), the molding material will buckle during heat shaping. The density of is 0.05~
It is preferable to set the foaming conditions so that a51i'/cJ i/r.

The manufacturing method of the present invention is as described above, in which a fibrous material and a thermoplastic resin emulsion are mixed in water and foamed, and the fibrous material and thermoplastic resin (sealing resin) are allowed to float together with foam to form a scum. Since this scum is extracted, fibrous materials and heat are removed from the water.
The 1E4 heavy fat naturally floats up due to the foaming power of the foam, and is evenly and three-dimensionally intertwined and dispersed, resulting in the resulting molding material having a low bulk specific gravity and high strength.

The fibrous material of the obtained molding material is bonded by thermoplastic resins with different glass transition temperatures that exist in an incompatible state, so it can be easily shaped without buckling by heating and pressurizing at a relatively low temperature. It also has excellent heat resistance as it does not deform even at high temperatures unless pressurized.

Therefore, the molding material obtained by zero injection is auto- uJII [
It is suitably used for applications such as interior materials, insulation materials for folded roofs, etc.

The final completion 811 will be explained below using an example.

Examples 30 parts by weight of recovered unbleached newspaper pulp, 8 parts by weight of styrene-acrylonitrile emulsion (solid content 50%), 4 parts by weight of vinyl acetate emulsion (solid content 50%), glass fiber (length 6III# + 1 diameter 8μ) ) 1 heavy bin 8 (ri,
2 parts by weight of polyethyleneimine (1% aqueous solution), borax (1%
% aqueous solution) 2 parts by weight to dioctylsuccinic acid s frt
t parts and 5 parts by weight of polyvinylmethylny-r tv O were supplied to 3000 parts by weight of water and mixed.

Mixing was done using an eccentric stirrer with irregular water flow. Note that the stirrer has a stirring blade 416 with its shaft suspended lx above the bottom of the vessel, and the blade rotates while just touching the bottom of the vessel. After stirring for 3 minutes at a total rotation speed of 1000 revolutions/rotation, the stirring was stopped and the device was left in the apparatus for 1 hour.The foam layer adsorbed on the fibers, styrene-acrylonitrile copolymer particles, and polyvinyl acetate particles floated as scum. 1-Separated.

"Floating" - Take out the separated scum, press it to a predetermined thickness, dehydrate it, and then cut it from the bottom with wire mesh K 1" scissors 130-1
The molding material was obtained by assimilation drying for 10 minutes in a hot air dryer at 50°C.

Bulk specific weight α08 (y/crA) of the obtained molding material
The thickness was 3.5 cm. The obtained molding material was cut into a size of 600 w x 150 mm and heated at 100°C.
When it was held horizontally for 72 hours, there was no thermal deformation at all.

The obtained molding material was preheated at 150° for 20 seconds and then fed into a pyramid-shaped mold with a minimum curvature of 9mm and a drawing ratio of 0.4 heated to 85°C to form a mold of 0.01 V4/cj. 10 with pressure
When the molded product was heated and pressed for seconds, a pyramid-shaped molded product was obtained without any buckling, cracking, etc.

patent applicant Fusui Chemical Industry Co., Ltd. Representative] I Mototoshi Numa 9-

Claims (1)

[Claims] 1 A fibrous material and two or more types of thermoplastic resin emulsions in which the resins have different glass transition temperatures and whose resins are incompatible with each other are mixed in water and foamed to form a thermoplastic resin on the fibrous material. 1. A method for producing a lightweight molding material, characterized in that a scum is formed by floating the material together with foam, and the scum 1 is scraped up. 2. Claim 1 in which the fibrous material is a vegetable fiber
How to use i as described in the section. 3. There are two types of thermoplastic resin emulsions, one of which has a glass transition temperature of 100°C or higher, and the other has a glass transition temperature of 5.
The manufacturing method according to claim 1 or 2, wherein the temperature is 0° C. or lower.