JPS6050595B2 - Composite material manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a composite material comprising a polypropylene fiber layer and other material layers.

The fibrous materials currently in use are mostly homogeneous, and many are non-uniform.

However, in recent years, as consumer demands have become more sophisticated and individualized, there has been an increasing desire for materials with more complex characteristics. Various types of composite materials are being produced in response to such purposes, and one such material is a composite material consisting of a fibrous layer such as a nonwoven fabric and a layer of other materials. Polyolefins such as polypropylene and polyethylene are inexpensive, have many excellent properties such as high strength, high hardness, light weight, and good chemical resistance, and are widely used for various purposes.

However, since it does not have a polar group in its molecule, it has weak thermal adhesion to foreign materials such as metals and wood. Therefore, in the past, polyolefin nonwoven fabrics and different materials were usually bonded together using adhesives. However, the use of adhesives complicates the process and, depending on the solvent used, has the drawback of causing pollution problems. On the other hand, various attempts have been made to improve the adhesive properties of polymers.

Hydroxyl groups, Methods of introducing a carboxyl group, a metal salt thereof, or an acid anhydride or anhydride thereof, etc. have been carried out (for example, Japanese Patent Publication No. 39-6810, Japanese Patent Application Publication No. 50-4144, Japanese Patent Application Publication No. 50-1016, etc.). Methods of adhering dissimilar materials by heat fusion using such polymers have already been used (for example, Japanese Patent Publication No. 42-6
178, Special Publication No. 45-12723, Special Publication No. 49-1094
3). However, bonding polyolefin fibrous materials and different materials using such polymers is a complicated process, and depending on the method of bonding, the characteristics of the fibers may be diminished. I tend to put it away. Therefore, a manufacturing method is desired in which the polyolefin fibrous material itself has strong adhesion to different materials, and only those materials are laminated and bonded. The present inventors discovered that it is possible to make a composite fiber by combining it with polypropylene, which is generally difficult to make into fibers with polymers that have strong adhesion to different materials, and succeeded in making them into fibers. (Patent application No. 51-125723, No. 51-14)
9597, 52-4168\52-93873),
However, by taking advantage of the characteristics of the composite structure of levers, we have developed the present invention, which solves the above problems and makes it possible to manufacture composite materials made of fibrous materials and different materials with a good texture without using adhesives. I did it. According to the present invention, not only a composite material made of different materials but also a composite material made of a synthetic resin material such as a sheet, and furthermore a composite material made of two or more types of fiber assembly layers both containing heat-fusible composite fibers. Needless to say, it is easy to manufacture. The present invention comprises a first component consisting of crystalline polypropylene and a polyolefin modified with an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a metal salt thereof (hereinafter sometimes referred to as acid-modified polyolefin). , polyolefins containing vinyl alcohol units or vinyl alcohol units and vinyl acetate units in the polymer (hereinafter sometimes referred to as vinyl-modified polyolefins) and having a melting point of 140°C or less (hereinafter referred to as these modified polyolefins). These modified polyolefins may be collectively referred to as modified polyolefins), mixtures of two or more modified polyolefins, or mixtures of these and other polyolefins with a melting point of 140°C or less (hereinafter referred to as modified polyolefins). and a second component consisting of a mixture of these and other polyolefins (sometimes collectively referred to as a modified polyolefin composition) are arranged in a parallel type or sheath-core type composite, and the second component is placed on the surface of the fiber. One or more fiber aggregate layers (hereinafter sometimes referred to as heat-fusible fiber aggregate layers) containing at least 2% by weight of heat-fusible conjugate fibers forming at least a part thereof, and another material layer. or two or more heat-fusible fiber assembly layers with different configurations are laminated, and if necessary, pressurized to create a layer with a melting point above the second component and below the melting point of the first component. This is a method for manufacturing a composite material characterized by heating it to a certain temperature.

The polypropylene component constituting the composite fiber used in the production method of the present invention is mainly composed of so-called isotactic polypropylene polymerized using a typical Ziegler-Natsuta type catalyst, and contains a small amount of atactic polypropylene or non-atactic polypropylene. There is no problem even if a crystalline ethylene propylene random copolymer is contained.

In order to improve spinnability, it is also possible to use polypropylene with a narrow molecular weight distribution obtained by adding an organic peroxide or the like to polypropylene obtained by polymerization or by thermally decomposing it using a special extruder. Alternatively, crystalline polypropylene obtained by random copolymerizing propylene with a small amount of one or more α-olefins such as ethylene, butene-1 or pentene-1 can also be used to increase flexibility. As the vinyl-modified polyolefin, a saponified ethylene-vinyl acetate copolymer (hereinafter sometimes referred to as saponified EVA) is suitably used. Saponification E
As VA, a copolymer obtained by saponifying an ethylene-vinyl acetate copolymer having a vinyl acetate component content of 5 to 4% by weight to a degree of saponification of 30% or more is preferable, and a modified material containing this copolymer at (up to) % by weight or more is preferable. Polyolefin compositions form good adhesive components. A modified polyolefin composition using an acid-modified polyolefin is one or a mixture of two or more acid-modified polyolefins, or a mixture of these and other polyolefins, and includes unsaturated carboxylic acids, unsaturated carboxylic acids, and unsaturated carboxylic acids in the acid-modified polyolefin. The total amount of saturated carbonic acid anhydride or metal salt thereof is 1k9 in the modified polyolefin composition.
One having an equivalent weight of 0.002 to 2y is preferably used.

Acid-modified polyolefins can be roughly divided into two types when viewed structurally.

One type is a homopolymer of ethylene, propylene, butene-1, etc. or a binary or tertiary copolymer thereof, or a copolymer mainly composed of olefins such as ethylene-vinyl acetate copolymer. The other type is the graft polymerization of unsaturated carboxylic acid or its acid anhydride in the presence of an agent, and the other type is a random polymerization of the above graft polymer or ethylene and unsaturated carboxylic acid or unsaturated carboxylic acid anhydride. It is made by reacting a copolymer with an ionic metal compound. The α-olefins of the polyolefins that form the backbone of the graft polymer are ethylene, propylene, and butene-1.
The present invention is not limited to, and polymers containing other α-olefins can be used. As the unsaturated carbonic acid, acrylic acid, methacrylic acid, maleic acid, etc. are preferably used, and as the unsaturated carboxylic acid anhydride, maleic anhydride is preferably used.

Metal ions include Na+, K+, Ag+, Cu+, C
Monovalent or divalent substances such as u+1, Ba+1, and Zn++ are used, and their chlorides, hydroxides, etc. are subjected to the reaction. Each of the modified polyolefins described above can be used as the second component either alone or in combination, but can also be used in combination with other polyolefins.

In this case, the melting point, hardness, texture, etc. of the second component can be finely adjusted. Suitable other polyolefins used in the mixture are ethylene, propylene, butene-1 homopolymers, binary or ternary copolymers, or ethylene-vinyl acetate copolymers. It is desirable that the melting point of the modified polyolefin composition be 140'C or less in order to obtain a nonwoven fabric with good shape. The preferable range of MI of the first component and the second component that form the heat-fusible conjugate fiber is as follows:
Those based on polyethylene and those based on polybutene-1 have a melt index (ASTMD-1238 (E
)) 1 to 50, more preferably 4 to 3. Those based on polypropylene are melt fluorate (ASTMD-12
38(L)) 2-601, more preferably 4-30.

Melt fluorate ratio after spinning (second component/first component),
Those in the range of 1.5 to 6 have a small shrinkage rate and good dimensional stability when made into a nonwoven fabric. The heat-fusible composite fiber used in the present invention has the above-described polypropylene as a first component, a modified polyolefin composition as a second component, these are arranged in a parallel type or sheath-core type composite, and the second component is is a conjugate fiber in which at least a portion, preferably 50% or more, of the fiber surface is formed. Composite ratio is 30:70~
70:30 is preferred. The production of such composite fibers is
This can be carried out using a conventional parallel-type or sheath-core type composite melt spinning apparatus. When acid-modified polyolefin is used, the spinning nozzle preferably has an L/D of 10 to 20. The fibers used may be in the form of undrawn yarns, or drawn yarns may be used as filaments, stable, tows, or short-cut. The heat-fusible fiber assembly layer containing heat-fusible fibers is used in the form of a web, nonwoven fabric, paper-like material, or the like.

When used as a dry non-woven fabric, the drawn yarn or undrawn yarn is crimped with about 10 threads per crimper by a method such as passing it through a crimper, and then cut to obtain a fiber length of 60 W.
Make it stable around L.

Although it is possible to obtain nonwoven fabrics using only heat-fusible composite fibers,
A web is formed by blending other fibers, such as stable fibers such as polyester, polyamide, polyacrylonitrile, or rayon, and heat-fused at a temperature above the melting point of the second component and below the melting point of the first component of the heat-fusible composite. A nonwoven fabric is formed once, and then it is laminated with a layer of a different material and heated again, or if necessary, simultaneously pressurized with a press of several K9 to several tens of kg to fuse it with the layer of a different material. Alternatively, by laminating the web-like layer with a layer of a different material and heat-sealing it, it is possible to obtain a composite material that integrates the non-woven fabric and the different material at the same time as forming a non-woven fabric. As the different material, a metal plate, metal foil, wood board, paper, cloth, etc. are used. By changing the pressing pressure during heating, the nonwoven fabric can be kept bulky or compacted. When used as a wet nonwoven fabric, synthetic paper can be obtained by shortcutting the heat-fusible conjugate fibers into several ruts and then forming the conjugate fibers alone or in a mixture with rayon, valve, poval, etc.

In this case, it is necessary that the composite yarn be a non-crimped yarn, and therefore it is preferably used as an undrawn yarn or a modified polyolefin composition containing low density polyethylene. The obtained synthetic fiber paper exhibits good thermal fusion properties with other different materials as in the case of dry-laid nonwoven fabric, and it is possible to obtain a composite material laminated with these different materials. In the present invention, it is not necessarily laminated with different material layers, but of course composite materials laminated with material layers such as plastic sheets, and even heat-fusible fiber aggregate layers, but with different shapes or configurations. things, for example,
Composite materials made by laminating nonwoven fabric and paper-like materials, composite materials made by laminating multiple fiber assembly layers with different contents of heat-fusible composite fibers, or laminations made by laminating multiple fiber assembly layers mixed with different types of other fibers. The manufacturing process also includes the use of multiple materials.

In the present invention, in order to heat-seal the heat-fusible fiber assembly layer and the mating material layer, the low melting point components of the composite fibers are melted using hot air, an infrared heater, heated steam, etc., and then the mating material layer and the mating material layer are melted. They can be easily bonded by a known method, such as by laminating and bonding, or by simultaneously melting and bonding using a heated roll or press machine.

Therefore, since no adhesive is used, there is no risk of pollution caused by harmful organic solvents, and the process is simplified. Composite materials obtained by the present invention can be produced in a wide variety of ways by selecting the type of composite fibers, fibers to be mixed with, dry or wet nonwoven fabric, press pressure during adhesion, type of different materials, etc. There is.

Its uses are wide-ranging, such as packaging materials, curtains, and interior walls. Composite materials make it possible to combine physical properties by laminating and integrating materials having different physical properties. The present invention enables the lamination and integration of materials that have conventionally been impossible, and provides a composite material with a wide variety of variations. The present invention will be explained below with reference to examples and how to put it into practical use.

The method for measuring each characteristic value in the examples is as follows.

Tensile strength: A sample of width 15 wrfn x length 15 CymL was tested using an Instron tensile tester with a sample length of 10-
Tensile measurement is performed at a tensile speed of 100 W1/min.

Peel strength: Width 207707 using Instron tensile tester! X
A test piece with a length of 10 mm is tensile measured at a tensile rate of 5 minutes/minute.

Example 1 As a heat-fusible composite fiber, the first component was polypropylene, and the second component was Surlyn 1652 (trade name of ionomer resin manufactured by DuPont, an ethylene-methacrylic acid copolymer containing Zn as an ionic metal). , methacrylic acid content 0.67y equivalent/Kg, methacrylic acid metal salt content 0.
077y equivalent/K9, MI5.2, melting point 99°C) 60
Weight% and low density polyethylene (Ml35.O, melting point 10
8°C) 40% by weight mixed polymer (total amount of carboxylic acid and carboxylic acid metal salt in the second component is 0.448
y equivalent/K9, melting point 105°C), and the composite ratio is 50
/50, spinning flow rate ratio is 25.1/8.6 (=2
．． 92) parallel composite fiber with a single yarn fineness of 6 denier.
A stable with a fiber length of 64Tf0n was used.

This composite fiber was made into a web with a basis weight of 62y1 through a card machine, and laminated with 1000μ thick kraft paper.
A composite material made of nonwoven fabric and kraft paper was obtained by pressing the 0'CllOk9lc pin for 3 times and fusion bonding for 2 times.

Adhesion between both materials was good. The tensile strength of this composite material is 18.4k9/15Tr0fL, and the tensile strength of kraft paper alone is 8.0k9/157077! It was hot.

Kraft paper has a great reinforcing effect and can be used as a packaging material. Example 2 The composite fiber stable used in Example 1 was made into a web with a basis weight of 46q1 through a card machine, laminated with 200μ thick aluminum foil, and bonded by pressing between 3 [phases] with 1300C110K91D.

Adhesion between both materials was sufficient. The tensile strength of this composite material was 11.1k9/15Tr0fL, and that of the aluminum foil alone was 1.22kg/157r0n. Aluminum foil has a great reinforcing effect and can be used as a blackout curtain. Example 3 The stable composite fiber used in Example 1 was run through a carding machine to form a web with a basis weight of 120qI77f' and a thickness of 27T! 1! Laminated with t(7) steel plate, 145℃, 3k
It was bonded by pressing at 91d for 1 minute.

The adhesion between both materials is good, and the peel strength is 1.1 kg.
/20 order. Such materials can be applied to interiors of automobiles and the like. Example 4 As a heat-fusible conjugate fiber, the first component was polypropylene and the second component was acid-modified medium density polyethylene (maleic anhydride graft copolymerized to medium density polyethylene, carboxylic acid anhydride content 0.17y equivalent) /K9, MlO.4, melting point 125°C), a mixed polymer consisting of 50% by weight of low density polyethylene (Ml23.l, melting point 108°C) (maleic anhydride content in the second component: 0.085y equivalent) /K9, melting point 120°C), a parallel composite fiber with a composite ratio of 50/501, a spinning flow rate ratio of 29.4/7.6 (=3.87), a single yarn fineness of 3 denier, and a fiber length. used a 64TSIL stable.

This composite fiber was applied to a card machine to form a web with a basis weight of 200yI, laminated with a piece of wood with a thickness of 2mm1, and heated at 130°C.
, 2k91cd for 1 minute to fuse and create a composite material consisting of the nonwoven fabric and the wood piece. The peel strength of the adhesive surface of this composite material was 1.3k9/20, indicating good adhesion.

Such materials can be used as indoor interior materials. Example 5 As a heat-fusible conjugate fiber, the first component is polypropylene,
The second component is saponified EVA (ethylene vinyl acetate copolymer with vinyl acetate content (maximum) weight % saponified to a degree of saponification of 80%, MIl7, melting point 106°C), the composite ratio is 50/50, and the spinning flow rate is The ratio is 51.4/10.9
(=4.72) parallel type conjugate fibers with single filament fineness of 3 denier and fiber length of 51 TWL were used.

This composite fiber and rayon (single yarn fineness 3 denier, fiber length 51Tf0n) were mixed at a ratio of 60% of the former and 40% of the latter, and a web with a basis weight of 50yI771 was formed through a carding machine.

This web was overlapped with a cotton cloth and fused through a calender roll set at 140°C to obtain a composite material.
Adhesion at the interface is good, and its peel strength is 1.2.
It was k9/20Tf$L. 1 Example 6 As a heat-fusible composite fiber, the first component was polypropylene, and the second component was acid-modified medium-density polyethylene (maleic anhydride graft copolymerized with medium-density polyethylene, maleic anhydride content 0.17y). Equivalent/K9, MllO.O
, melting point 125°C) and ethylene vinyl acetate copolymer (vinyl acetate content 2% by weight, MI2O, melting point 85°C)
) 95% by weight of a mixed polymer (maleic anhydride content in the second component is 0.0085q equivalent/K9, melting point 86
°C), a sheath-core composite fiber with a composite ratio of 50/501 and a spinning flow rate ratio of 38.5/10.2 (=3.77), with a single fiber fineness of 3 denier and a fiber length of 64T! A $L stable was used.

This composite fiber was applied to a carding machine to form a web having a basis weight of 200 yId. This web was laminated with a polypropylene sheet of 130'Cl3Ok9lc thickness.
I breathed it for 3 circles and 2 minutes to fuse it. The adhesion of this composite material at the interface is good, and the peel strength is 0.5k9/
It was 20T0rt. Example 7 As a heat-fusible composite fiber, the first component was polypropylene, and the second component was an acid-modified polypropylene copolymer (a ternary crystalline copolymer containing 113.2% by weight of butene and 1.1% by weight of ethylene). Graft copolymerization of acrylic acid to polypropylene copolymer, carboxylic acid 5 content 1.3f equivalent/K9, M
FRl3. Aphrodisiac point 13rC), and the composite ratio is 50/5
0, the flow rate ratio after spinning is 30.1/13.1 (=
2.28) parallel type composite fiber with a single fiber fineness of 2.5 denier and a fiber length of 5 wn was used.

The composite fibers and 3 d each of the bulbs were put into 30 f of water, stirred for 3 minutes in a washing machine to uniformly disperse them, and then allowed to stand for 1 minute.

Subsequently, paper was made from this dispersion using a 20-mesh standard sieve, and the paper was left to stand horizontally for 15 minutes to drain water, to obtain wet synthetic paper. Next, this wet synthetic paper was sandwiched between two pieces of paper (Toyo Roshi, NO5O), dried in a dryer at 80°C for 3 hours, and then the paper was peeled off to obtain a synthetic paper with a basis weight of 80yIrrI by the wet process. . The obtained synthetic fiber paper is 200mm thick.
Laminated with μ aluminum foil, 140°C110k91cd
Press for 1 minute to fuse the aluminum foil and synthetic paper to obtain a composite material made of aluminum foil and synthetic paper.

Adhesion between the two interfaces was sufficient. Example 8 The composite fiber of Example 4 at 30° C. and 70% of rayon (single fiber fineness 3 denier, fiber length 51 T!Rm) were blended and passed through a card machine to form a web with a basis weight of 60 da 1 d.

This web and the synthetic paper obtained in Example 7 were laminated, and
Pressure was pressed at 0° C. and 10 k91 cd for 1 minute to obtain a composite material consisting of nonwoven fabric and synthetic paper. The adhesion of both surfaces was good. Example 9 The first component is polypropylene, and the second component is acid-modified high-density polyethylene copolymer (graft copolymer of maleic anhydride with high-density polyethylene as the backbone, carboxylic anhydride content 0.082y equivalent) /K9, Mll2.4, melting point 1
30°C) and 9% by weight of high density polyethylene (MI32, melting point 130°C) (maleic anhydride content in the second component: 0.00164y equivalent/K9)
, melting point 130℃), parallel type composite fiber with a composite ratio of 50/50, spinning flow rate ratio of 54.6/14.3 (=3.82), single yarn fineness of 4 denier, and fiber length of 64T.
! r! Ft stable was used.

This composite fiber was applied to a card machine with a basis weight of 50y1rrf,
This led to the formation of a web of This web was laminated with various different materials, pressed at 145° C. and 10k91d for 1 minute, and heat fused to obtain the results shown in the table below. Comparative Example The following results were obtained in the same manner as in Example 9 except that only high-density polyethylene was used as the second component.

Claims (1)

[Claims] 1. A first component consisting of crystalline polypropylene and a polyolefin modified with an unsaturated carboxylic acid, an unsaturated carboxylic acid anhydride, or a metal salt thereof (hereinafter referred to as acid-modified polyolefin). , polyolefins containing vinyl alcohol units or vinyl alcohol units and vinyl acetate units in the polymer (hereinafter referred to as vinyl-modified polyolefins), with a melting point of 140°C or less (
Hereinafter, these modified polyolefins are collectively referred to as modified polyolefins), mixtures of two or more modified polyolefins, or mixtures of these and other polyolefins with a melting point of 140°C or less (hereinafter these modified polyolefins). A second component consisting of a polyolefin and a mixture of these and other polyolefins (generally referred to as a modified polyolefin composition) are arranged in a parallel type or sheath-core type composite, and the second component covers at least a portion of the fiber surface. One or more fiber aggregate layers containing 20% by weight or more of heat-fusible composite fibers (hereinafter referred to as heat-fusible fiber aggregate layers) and one or more other material layers. Laminated or laminated two or more heat-fusible fiber aggregate layers of different configurations,
A method for producing a composite material, which comprises pressurizing as necessary and heating to a temperature above the melting point of the second component and below the melting point of the first component. 2. The modified polyolefin composition uses a copolymer obtained by saponifying an ethylene vinyl acetate copolymer having a vinyl acetate component content of 5 to 40% by weight to a degree of saponification of 30% or more as a vinyl-modified polyolefin, and the saponified copolymer is 30% by weight.
The method for producing a composite material according to claim 1, which contains the above. 3. The modified polyolefin composition is one type of acid-modified polyolefin, or a mixture of two or more types of acid-modified polyolefin, or a mixture of these and other polyolefins, and is a mixture of unsaturated carboxylic acid and unsaturated carboxylic acid contained in the acid-modified polyolefin. 2. The method for producing a composite material according to claim 1, wherein the total amount of anhydride or metal salt thereof is 0.002 to 2 g equivalent per 1 kg of the modified polyolefin composition. 4. The method for producing a composite material according to claim 1 or 3, wherein the acid-modified polyolefin is a graft copolymer of an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride based on a polyolefin. 5 Acid-modified polyolefin is a graft copolymer of an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride, or a random copolymer of ethylene and an unsaturated carboxylic acid or an unsaturated carboxylic acid anhydride, which has a polyolefin as its backbone, The method for producing a composite material according to claim 1 or 3, wherein the composite material is produced by reacting a synthetic metal compound. 6. The polyolefin that is the backbone of the graft copolymer is a homopolymer of ethylene, propylene, butene-1, a binary or ternary copolymer thereof, or an ethylene-vinyl acetate copolymer. A method for producing a composite material according to item 4 or 5. 7. The manufacturing method according to any one of claims 1 to 6, wherein the fiber assembly layer containing heat-fusible fibers is a web, a nonwoven fabric, or a paper-like material. 8. The method for producing a composite material according to any one of claims 1 to 7, using a metal plate, metal foil, wood board, paper, cloth, or plastic sheet as the other material layer. 9 The melt fluorate of the second component is 1 of that of the first component.
．． Production of the composite material according to any one of claims 1 to 8, using heat-fusible composite fibers spun by a parallel composite spinning device using fibers that are 5 to 6 times larger. Method.