JPH0441910B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a composite molded material with improved moldability that has the rigidity and appropriate elasticity to enable deep drawing, and is useful as interior materials for automobile ceiling materials, door trims, rear shells, seat bags, trunk parts, etc. .

[Conventional technology]

For automotive floor carpets, we use needle-punch carpets made of non-woven fiber mat impregnated with SBR latex or aqueous resin emulsion with a glass transition point of 10°C or less, and high-melting point thermoplastic resin fibers with a melting point of 100 to 130°C. A needle-punch carpet made of non-woven mat made of mixed fibers with a resin fiber binder having the following properties is heated to a temperature above the melting point of the resin in the emulsion or the resin fiber binder, and then press-molded to a shape similar to that of an automobile floor. Padding materials molded into the above are known, and resin felts made of phenol-aldehyde condensation resin filled with fibers, foamed synthetic resins,
Materials that can withstand temperatures of over 100°C are also used, such as polypropylene composites and polypropylene cardboard.

[Problems to be solved by the invention]

The above-mentioned known laying materials are not rigid or rigid by themselves.
Resin felt lacks elasticity, moldability (mold fidelity), breathability, and lightness, and among the above materials used for laying materials, resin felt has poor rigidity, heat resistance, shape retention, and dimensions. Although it has excellent stability,
Polypropylene cardboard has poor moldability, impact resistance, breathability, and lightness.While polypropylene cardboard has excellent rigidity and lightness, it also lacks breathability.
Since corrugated material is used, the strength is directional. Further, although foamed synthetic resins such as crosslinked polystyrene are excellent in light weight, they have drawbacks such as poor heat-resistant shape retention stability and poor bending resistance.

[Means to solve the problem]

In view of the above points, the present invention constitutes a molded material with a composite structure in which a needle punch carpet for the surface layer which has elasticity and a needle punch carpet for the backing layer which has imparted rigidity and formability are bonded together with a hot melt adhesive. However, it has been improved so that particularly excellent moldability can be maintained without deteriorating the original function of the molding material. Therefore, the purpose of the present invention is to obtain surface layer needles with a fiber bulk density of 0.5 g/cm ³ or less and a basis weight of 200 to 500 g/m ^{2 obtained by impregnating and drying an emulsion of a resin with a glass transition point of 80°C or higher} . The bulk density of the fiber obtained by impregnating and drying a punch carpet and an emulsion of a resin with a glass transition point of 80℃ or higher is
A composite molded material with improved moldability, made by bonding together a backing needle punch carpet with a weight of 0.15 to 0.5 g/cm ³ and a basis weight of 300 to 2000 g/m ² using a seed hot melt adhesive. This is achieved by

【Example】

First, each component used to implement the present invention will be explained. Needle punch carpet for the surface layer Needled fiber mat made from fibers such as nylon, polyethylene terephthalate, wool, etc., or a carpet with a melting point to give rigidity
60~200℃ thermoplastic resin fiber binder 15~
50% by weight and synthetic or natural fibers having a melting point 35°C or more higher than the melting point of the thermoplastic resin85
The material obtained by needling fiber mat consisting of ~50% by weight is impregnated with an emulsion of a resin with a glass transition point of 80℃ or higher, and the dry fiber bulk density is
Use one with a weight of 0.5 g/cm ³ or less. The latter material having added rigidity is manufactured by a known nonwoven fabric manufacturing method. i.e. 1.2-300 denier, fiber length
25~150mm thermoplastic resin fiber binder 15~
50% by weight, 1.2-300 denier, fiber length 25-150
85 to 50% by weight of synthetic resin and/or natural fibers are sufficiently mixed and opened, and then fed to a web forming device to obtain the desired fiber weight for a card formed from the mixed fibers. The web (fiber mat) obtained by stacking the fibers together is vertically needled to intertwine the fibers and temporarily fasten them together. The fiber binder is used in a proportion of 15 to 50% by weight, preferably 20 to 40% by weight of the fiber mat weight. If it is less than 15% by weight, the contribution to improving the rigidity and dimensional stability of the carpet obtained by press molding will be small. On the other hand, if it exceeds 50% by weight, it becomes like resin felt, hard and brittle with impaired fiber texture (elasticity). In addition, the fiber bulk density is 0.5
If it exceeds g/cm ³ , the fiber packaging will become dense and the texture of the fibers will be impaired. Needle punch carpet for backing Nonwoven fabric mats are 1.2 to 300 denier, fiber length
By supplying 25 to 150 mm natural fibers and/or natural fibers that have been sufficiently mixed and opened to a web forming device, and stacking the cards formed from the fibers to the desired fiber weight. Manufactured. Thermoplastic resins such as polyethylene terephthylate, polyamide, and polypropylene are used as raw materials for synthetic fibers. Further, as natural fibers, cotton, linen, wool, etc. are used. All of these may be scraps (reused items). Among these, 15 to 50% by weight of thermoplastic resin fiber binder is used as a material for non-woven mats.
In order to adjust the apparent density when compressed, it is recommended to use a mixture of fibers consisting of 85 to 50% by weight of synthetic fibers or natural fibers having a melting point 35°C or more higher than the melting point of the thermoplastic resin. It's convenient. A web (fiber mat) in which cards made of the above-mentioned fibers are stacked is vertically poked with a needle, and the fibers are intertwined in the vertical direction, thereby temporarily fixing each card (so-called needling). An aqueous emulsion of a thermoplastic resin with a glass transition point of 80°C or higher is added to this fiber mat so that the resin solid content of the emulsion is 15 to 300% of the weight of the fiber mat.
% by weight, preferably 30 to 150% by weight, and then heat-dried at a temperature higher than the melting point of the emulsion resin, for example, 100 to 250°C, to remove moisture, thereby producing a moldable nonwoven fabric. Manufactured. Particularly when the mat also contains a fiber binder, the resin is heated to a temperature that dissolves the fiber binder as well as the emulsion resin, making it easier to adjust the apparent density. The thermoplastic resin of the emulsion impregnated into the fiber mat has a moldable temperature range of 80 DEG C. or higher, preferably 120 DEG to 180 DEG C., and a particle size of 0.01 to 5 microns. Specifically, a lower ester copolymer of styrene and acrylic acid (ester has 2 to 6 carbon atoms),
Examples include thermoplastics such as methacrylate/acrylic acid lower ester copolymers, vinylidene chloride copolymers (vinylidene chloride content is 85% by weight or more), and styrene/diene copolymers. Some of these are Acronal from Yuka Verdice Co., Ltd.
YJ-1100D, 8393D, 7082D, Deiofan
It is sold under product names such as 192D. Examples of means for applying or impregnating the fiber mat with the emulsion include a licker roll, a squeezing roll, a spray gun, and dipping. Generally, in order to completely impregnate the fiber mat with the emulsion, the applied emulsion is squeezed using squeeze rolls. The emulsion can be applied from one or both sides of the fiber mat. Also,
It is possible to impregnate the entire fiber mat, to have a partially unimpregnated portion in the center, or to have a partially unimpregnated portion on one side. By allowing the unimpregnated portion to exist in the fiber mat, the cushioning properties of the obtained nonwoven fabric can be prevented from being extremely reduced. Fillers such as calcium carbon, iron oxide, ferrite, barium sulfate, etc. may be blended into this emulsion in order to impart a sense of weight to the obtained nonwoven fabric, and fillers such as low density polyethylene, polystyrene, etc. may be blended in order to impart moldability. It is also possible to blend powder of low melting point resin such as ethylene/vinyl acetate copolymer. The fiber mat coated and impregnated with emulsion is heated to a temperature above the melting point of the emulsion resin to remove water, and the apparent density of the moldable fibers is reduced.
A nonwoven fabric of 0.15-0.5 g/cm ³ , preferably 0.17-0.3 g/cm ³ is produced. During this heat-drying process, some of the resin particles in the emulsion exist in the fiber mat in a particulate state, and some form a film, which strengthens the entanglement between the fibers and makes the fiber mat moldable. and imparts rigidity. Here, the apparent fiber density of the moldable nonwoven fabric is 0.15
~0.5g/ ^cm3 is given when the fiber apparent density is 0.15.
This is because if it is smaller than g/cm ³ , the space-filling effect of the mat of a binder such as an emulsion resin or a fiber binder that binds fibers together will be low, and the bonding force between the fibers will be small and they will easily come off. vice versa,
When the apparent fiber density exceeds 0.5 g/cm ³ , the fiber layer becomes dense and has poor elasticity like resin felt, and the air permeability also decreases. Resin emulsion The thermoplastic resin of the emulsion applied or impregnated into the needle punch carpet to impart moldability has a moldable temperature range of 80°C or higher, preferably
The particle size is 0.01-5 microns at 100-180°C. Specifically, styrene/acrylic acid lower ester copolymers (ester has 2 to 6 carbon atoms), methacrylate/acrylic acid lower ester copolymers, vinylidene chloride copolymers (vinylidene chloride content is 85% by weight or more) ), thermoplastic resins such as styrene-diene copolymers. Optimally, (a) polyn-propyl methacrylate (Tg 81°C),
Polystyrene (100℃), polyacrylonitrile (100℃), polymethyl methacrylate (105℃),
In addition to aqueous emulsions of homopolymers such as polymethacrylic acid (130°C), polyitaconic acid (130°C), and polyacrylamide (153°C), (b) vinyl monomer 50, which is the raw material for these polymers.
-100% by weight, preferably 65-95% by weight, and other vinyl monomers such as 2-ethylhexyl acrylate (Tg 85°C), n-butyl acrylate (-54°C), ethyl acrylate (-22°C). ), isopropyl acrylate (-5℃), 2-ethylhexyl methacrylate (-5℃), n-propyl acrylate (8℃), n-butyl methacrylate (20℃), vinyl acetate (30℃), acrylic acid t
-butyl (45℃), 2-hydroxyethyl methacrylate (55℃), ethyl methacrylate (65℃)
), isobutyl methacrylate (67℃), vinyl chloride (79℃), etc. or vinylidene chloride (-18℃), etc.
°C) Aqueous emulsion of a copolymer with 50% by weight or less, preferably 35 to 5% by weight (c) Resin aqueous emulsion with Tg of +80 to 155°C 50
~97% by weight, preferably 55-95% by weight, Tg
Resin aqueous emulsion with temperature below -85~80℃50～
3% by weight, preferably 45 to 5% by weight. Fillers such as calcium carbon, iron oxide, ferrite, and bilum sulfate may be added to this emulsion to give the obtained nonwoven fabric a sense of weight, and fillers such as low-density polyethylene or polystyrene may be added to give moldability. It is also possible to blend a powder of a low melting point resin such as ethylene/vinyl acetate copolymer. Thus, means for applying or impregnating the fiber mat of the carpet with the emulsion include licker rolls, squeezing rolls, spray guns, dipping, and the like. Generally, in order to completely impregnate the fiber mat with the emulsion, the applied emulsion is squeezed using squeeze rolls. The emulsion can be applied from one or both sides of the fiber mat. The fiber mat coated or impregnated with the emulsion is heated at 60 to 250°C to remove moisture, and a needle punch carpet with bonded fibers is produced. During this heating and drying process, some of the resin particles in the emulsion remain in the fiber mat in a particulate state, and some form a film that strengthens the intertwining of the fibers and also strengthens the fiber mat of the carpet. It provides moldability and rigidity. Hot melt adhesive (1) Nonwoven fabric binder The nonwoven fabric of the thermoplastic resin fiber binder is made of polyethylene, polypropylene, linear polyester, polyamide, etc. fibers, polyethylene/polypropylene laminate fibers, etc. with a melting point of 60 to 200℃,
Aeration with a basis weight of 6 to 200 g/m ² , preferably 20 to 60 g/m ² , preferably obtained by intertwining resin fibers of 2 to 12 denier and 2 to 8 mm fiber length at 90 to 170°C by a spunbond method. It has a wall thickness of 5 to 500 microns. In addition, this fiber binder is made by melting resin pellets such as polypropylene, polyester, polyamide, etc. using an extruder and extruding them through a die with a logarithmic number of narrow holes in a continuous shape, and blowing them in the wind so that the individual fibers do not converge. It may also be produced by drawing out the material, depositing it in a screen shape below the die, and pulling it off with a winder. Such fiber binder nonwoven fabrics have many gaps through which water can pass, and are manufactured by Diabond Industries Co., Ltd. under the trade name Meltron W. Polyamide diameter ones are PAY-200 and PAS-200, and polyester-based ones are ES-. 500, the ethylene/acetic acid copolymer type is grade name Y7, and the polypropylene type is Syntex PK-103, PK-106, PK-404, PK- from Mitsui Petrochemical Industries, Ltd.
408, etc., polyethylene products are Admel product names, and Kureha Sen'i Co., Ltd.
A more similar non-woven fabric is LNS under the trade name DYNAC.
-0000, LNS-2000, ES-00, B-1000, B
It is sold with grade names such as -2000 and B-3000. (2) Resin film The material resin for the adhesive film is a thermoplastic resin with a melting point of 70 to 200°C, such as ethylene/vinyl acetate copolymer, polyethylene, ethylene/acrylic acid copolymer, or its metal salt (K , Li, Na, Zn, Pb), polypropylene, etc. This resin is melted and kneaded using an extruder, then melted and extruded from a die into a film, and introduced between a needle punch carpet for the surface layer and a needle punch carpet for the backing layer.
The three parts are integrated by compression using a compression roll. The thickness of the resin film is 20~2000mm
microns, preferably 35-200 microns. Integrating the above needle punch carpet on both the front and back sides with a nonwoven fabric binder or resin film,
In addition to the method described above, the needle punch carpet for the surface layer, the nonwoven binder or resin film, and the needle punch carpet for the back layer are layered in this order using guide rolls, and then heated at 150 to 200°C to dry the emulsion and remove the emulsion resin. A method in which the above resin film or nonwoven fabric binder is melted and then press-molded to integrate and shape the three parts, or a molten resin film (or nonwoven fabric binder) is previously attached to one of the surface layer or lining needle punch carpet. There is a method in which the two needle punch carpets are laminated and then the other needle punch carpet is adhered using a pressure roll. Next, the present invention will be described with reference to the accompanying drawings. A surface needle punch carpet 1 with a wall thickness of 2 to 5 mm and a backing needle punch carpet 2 with a wall thickness of 2 to 10 mm are formed into a sheet-like hot melt. They are adhered with adhesive 3 to form a composite molded material. In the composite molded material having this structure, if an outer covering material 4 such as under felt, foamed polystyrene sheet, polypropylene sheet, non-woven fabric, etc. is polymerized on the backing needle punch carpet 2 side, and this is heated and compression molded, the composite material can be formed. A decorative composite molded material whose back surface is finished with the outer covering material 4 is obtained. In addition, after heating the backing needle punch carpet 2 side, if a reinforcing material such as plywood, resin felt, or cardboard is superimposed on the carpet 2 and bonded under pressure, this composite molded material can be used for the rear back of an automobile. It can be effectively used as trim material. In particular, if underfelt is used as the outer cover material 4 and a resin film is used as the adhesive, rainwater that has entered from the surface needle punch carpet 1 side is blocked by the resin film layer, and the underfelt is completely protected from rainwater. can be protected. Example: Plain type needle punch carpet made of 350g/ ^m2 polyester fiber has a softening point of approx.
Acrylic latex 80g/m ² (solid content) at 100℃
After coating and drying, the fiber bulk density is 0.08%g/cm ³
Needle punch carpet 1 for surface layer was obtained. On the other hand, 20% of recovered polypropylene (melting point 164℃) fiber binder with 15 denyl fiber length of about 100 mm and 15
Fiber mat (850
g/ ^m2 ) using a 15-18-32-3RB needle.
Needled at a rate of 50 pieces per square inch,
A needle carpet with a wall thickness of about 8.1 mm and an apparent density of 0.01 g/cm ³ was obtained. Styrene (85%) - methyl acrylate (12%) -
Aqueous emulsion of acrylic acid (3%) terpolymer (resin average particle size 0.1 micron, solid content 50%,
The softening point of the resin is approximately 120°C) is applied so that the resin content is 350g/m ² .Then, the entire web is impregnated with the emulsion using Nitsuprol, and this is dried at 190°C to determine the fiber bulk density. Needle perch carpet 2 for backing with a weight of 0.18 g/cm ³ was obtained. The above-mentioned needle punch carpets 1 and 2 are guided by guide rolls, and the ethylene/vinyl acetate copolymer is melted and kneaded between them by an extruder and extruded from a die at 190°C to a thickness of 50 microns. The three components were polymerized with Nipprol and compressed to obtain an integrated composite molded material. In addition, after heating the backing needle punch carpet 2 side of this composite molding material at 190°C to melt the polypropylene fiber binder and emulsion resin, an under felt (outer covering material 4) with a wall thickness of 10 mm was applied. This was press-molded and shaped. The obtained composite molded material was faithful to the cavity of the mold. Example A fiber mat obtained by needling a randomly stacked web of recovered polyethylene terephthalate (melting point 264°C) fiber waste with a fiber length of 75 to 125 mm and a denier of 15 as a nonwoven fiber mat before being impregnated with emulsion. A composite molded material in which the three layers were integrated was obtained in the same manner as in the ^example except that the compound was used. Example In the example, a nonwoven fabric made of polypropylene fiber binder "Syntex" manufactured by Mitsui Petrochemical Industries, Ltd. was used on the back side of the needle punch carpet 1 for the surface layer.
2PK-110'' (trade name, basis weight 50g/m ² , fiber type 3 denier), a needle punch carpet 2 for backing was further polymerized under this nonwoven fabric, and then this laminate was heated to 190°C. After drying the emulsion and melting the nonwoven fabric and the polypropylene fiber binder of the above-mentioned carpet 2, pressure molding was performed using a press molding machine to obtain a composite molded material in which each layer faithfully formed in the mold was integrated. In this case, the surface needle punch carpet 1 has a wall thickness of 4.2 mm and a fiber bulk density of 0.083 g/cm ³ , and the backing needle punch carpet 2 has a wall thickness of 5.0 mm and a fiber bulk density of 0.17 g. /cm ^3.Example In the example, as needle punch carpet 1 for surface layer, 20% by weight of recovered polypropylene fiber binder with 15 denier and fiber length of about 100 mm was used.
and 350 g/m ² mixed fiber of 80% polyethylene terephthalate fiber, 15 denier, fiber length 75-125 mm.
Plain type needle punch carpet made of acrylic latex 80 with a softening point of 120℃.
A composite molded material was obtained in the same manner as in the example except that the composite material was coated with an amount of g/m ² (solid content) and dried. Surface layer needle punch carpet 1 and backing needle punch carpet 2 used in reference examples and examples
Each was individually molded to obtain each laying material. The physical properties of the laying materials according to the above Examples and Reference Examples were evaluated by the following method, and the results are shown in the "Table" below. Bending strength Fix one end of the test piece (length 120 mm, width 30 mm),
The bending resistance value was measured when a deformation load was applied perpendicularly to the sample piece at a rate of 50 cm/min using an Instron type testing machine at a position 100 mm in the longitudinal direction from the fixed point. Waterproofness After heating the non-woven fabric to 190℃, a tray-shaped container with length and width of 200mm and depth of 20mm was formed by compression molding under the condition of 0.35Kg/cm ² G. When water was inserted into the container, the container If water leaks more quickly and continuously, it is considered poor waterproofness, and if water does not pass through it at all, it is considered good waterproofness. Cushionability The initial wall thickness when a load of 50 g/cm ² is applied to the laying material is to, then the wall thickness when a load of 400 g/m ² is applied for 1 minute is t ₁ , this load is removed, and 1 minute When the wall thickness after elapsed time is t ₂ , compression ratio = to-t ₁ /to × 100 compressive elastic modulus = t ₂ – t ₁ / to-t ₁ × 100 deformation rate = (1-t ₂ /to )×100, and those with a small deformation rate and a small thickness change rate were considered to have good cushioning properties. Rigidity Sample piece (length 300mm, width 300mm)
Place it on a table with a width of 300mm x 300mm and a width of 250mm x 250mm.
A pressure of 2.0 Kg/cm ² is applied to the center of the sample piece with a diameter of 15 mm, and if the sinking distance of the center position of the sample piece is within the wall thickness of the sample piece, the rigidity is considered to be good. Those exceeding this value were considered to have poor rigidity. Adhesive strength A composite molded material with a width of 50 mm and a length of 200 mm was used as a sample.
At one end, the surface material and backing material were each fixed in an Instron type testing machine, and a 180 degree peel test was performed at a speed of 200 mm/min.

【Effect of the invention】

The present invention is as described above, and as confirmed from the table below, it is possible to provide a composite molded material with particularly excellent moldability at a low cost without reducing the rigidity and elasticity required for interior materials. There are advantages,
It is extremely effective as a molding material for interior materials of automobiles, etc.

【table】 [Brief explanation of drawings]

The drawing is a perspective view showing an embodiment of the invention. In the figure, 1 is a needle punch carpet for the surface layer,
2 is a needle punch carpet for backing, and 3 is a sheet hot melt adhesive.

Claims (1)

[Claims] 1. Fibers obtained by impregnating and drying an emulsion of a resin with a glass transition point of 80°C or higher and having a bulk density of 0.5 g/cm ³
Hereinafter, a fiber bulk density of 0.15 to 0.5 g/cm ³ obtained by impregnating and drying a needle punch carpet for the surface layer with a basis weight of 200 to 500 g/m ² and an emulsion of a resin having a glass transition point of 80° C. or higher, The basis weight is 300~2000g/
1. A composite molded material with improved moldability, characterized in that it is made by integrally bonding a needle punch carpet for backing of m ² with a sheet hot melt adhesive. 2 Sheet hot melt adhesive has a basis weight of 6~
200 g/m ² and is a water-permeable nonwoven fabric of a thermoplastic resin fiber binder having a melting point of 60 to 200°C. mold material. 3. The sheet-like hot melt adhesive is a water-impermeable thermoplastic resin film extruded from a die and having a melting point of 70 to 200°C, and has improved moldability as set forth in claim 1. Composite molding material. 4 Needle punch carpet for the surface layer is a needle punch made of a mixed fiber of 15 to 50% by weight of a fiber binder and 85 to 50% by weight of resin fibers having a melting point at least 35°C higher than the melting point of the resin of the fiber binder. A composite molded material with improved moldability according to claim 1, which is a carpet. 5 Needle punch carpet fibers for backing
The molding according to claim 1, wherein the amount of the emulsion of the resin having a glass transition point of 80° C. or higher is 15 to 300% by weight based on the solid content of the emulsion based on 100 parts by weight. Composite molding material with improved properties. 6 The material fiber of the needle punch carpet for backing has a melting point 35℃ higher than the melting point of the emulsion resin.
50 to 85% by weight of thermoplastic resin fibers whose melting point is 200℃ or higher, and whose melting point is 200℃ or higher.
60~170℃ thermoplastic resin fiber binder 50~
15% by weight of the composite molded material having improved moldability as claimed in claim 1. 7. The composite molded material with improved moldability according to claim 3, wherein the thermoplastic resin film has a wall thickness of 20 to 2000 microns.