JPH042882A - Nonwoven fabric impregnated with diacetylene resin - Google Patents

Abstract

PURPOSE:To provide the subject nonwoven fabric having characteristics such as light weight, extremely high rigidity and dimensional stability by impregnating a nonwoven fabric with a specific diacetylene compound and/or a polymer thereof and subsequently curing the compound. CONSTITUTION:A diacetylene compound represented by the formula (R, R' are 2-8C unsaturated hydrocarbon group; X, X' are ester bonds or ether bonds) and/or a polymer thereof dissolved in e.g. an organic solvent, is impregnated into an organic or inorganic nonwoven fabric and subsequently subjected to a heating treatment, etc., to provide a diacetylene resin-impregnated non-woven fabric wherein the diacetylene compound is cured. The prepared non-woven fabric has extremely high rigidity and hardness and further having characteristics such as light weight and dimensional stability and composite products of the nonwoven fabric with plastics are suitable for lightweight structural materials, precision mechanical parts, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resin-impregnated nonwoven fabric that has extremely high rigidity and hardness, is lightweight, and has excellent dimensional stability. Specifically, the present invention relates to a resin-impregnated nonwoven fabric obtained by impregnating a nonwoven fabric with a diacetylene compound that has excellent permeability, curing reactivity, and excellent properties of the cured product, and a resin-impregnated nonwoven fabric material obtained by curing the nonwoven fabric.

[Prior art]

A lightweight and rigid nonwoven fabric made by impregnating nonwoven fabric with thermosetting resins such as epoxy resins, phenolic resins, and unsaturated polyester resins, vinyl monomers such as methyl methacrylate, and polystyrene, and their polymers as impregnating resins. Plastic composites are utilized. However, for applications that require higher rigidity, composite materials made of long fibers such as UD prepreg are used, and nonwoven fabrics are almost never used. For this reason, methods have been recognized for imparting higher rigidity, hardness, dimensional stability, etc. to nonwoven fabric/plastic composites without impairing the isotropy and lightness of nonwoven fabrics.

However, this is an extremely difficult problem that cannot be solved using existing impregnating resins and processing molding techniques.

[Problems to be Solved by the Invention] In conventional technology, when a nonwoven fabric is impregnated with resin, most of the resin fills the voids inside the nonwoven fabric, which increases the specific gravity and reduces the lightweight characteristics of the nonwoven fabric. It will be lost.

In addition, with conventional resins, no matter how much the impregnated amount is increased, there is a limit to the performance of the resin itself, so the above-mentioned required performance could not be sufficiently improved.

The present invention provides a diacetylene resin-impregnated nonwoven fabric that solves these drawbacks and problems.

[Means for Solving the Problems] The present inventors have been involved in the development of crosslinkable materials that can exhibit high elastic modulus and hardness, and have already developed various diacetylene compounds and polymers thereof. discovered a new high-performance crosslinking material (Japanese Patent Application Laid-Open No. 1986-9
6144, JP 63295639, JP 63-295612).

The present inventors further conducted research on the possibility of composite materials made of these diacetylene compounds and various materials such as metals, ceramics, plastics, and wood, and in the process, certain diacetylene compounds were used to form nonwoven fabrics. We found that it penetrates extremely well. Therefore, we further investigated the impregnation method of nonwoven fabric and diacetylene compound, the curing reactivity of the impregnated material,
As a result of intensive study on the physical properties of the material after curing,
The inventors have discovered that a composite material of a nonwoven fabric and a certain type of diacetylene compound can be made into a resin/nonwoven composite material that is lightweight and has excellent performance, and has thus arrived at the present invention.

That is, the present invention is as shown below.

1) A resin-impregnated nonwoven fabric obtained by impregnating a nonwoven fabric with a diacetylene compound represented by formula (I) and/or a polymer of the diacetylene compound.

RX CHz c=c c=c C1h X
'R' (I) (However, R and R' are unsaturated hydrocarbon groups having 2 to 8 carbon atoms, and x and x' represent an ester bond or an ether bond.) 2) In formula (1) A resin-impregnated nonwoven fabric obtained by impregnating a nonwoven fabric with the diacetylene compound shown and/or a polymer of the diacetylene compound and curing the impregnated nonwoven fabric.

R-X-CHz-CaC-C=C-CHz-X'-R
(However, R and R' are unsaturated hydrocarbons having 2 to 8 carbon atoms, and x and x' represent ester bonds or ether bonds.) There are no particular restrictions on the type of nonwoven fabric used in the present invention. Instead, organic and inorganic nonwoven fabrics or a mixture of these nonwoven fabrics are used.

The fiber base materials that make up the nonwoven fabric include cotton, linen, wool,
Rayon, cuprammonium rayon, acetate, polyamide, polyester, polyacrylonitrile, polyvinyl alcohol, polyolefin, polyphenylene sulfide, aramid, polyetheretherketone, polysulfone, glass, silica, alumina, or mixtures thereof are used. In addition, its form is wet,
Nonwoven fabrics made by dry process, melt blow process, melt process, etc. are used, and laminates made by combining these may also be used.

In the present invention, the diacetylene compound represented by formula (1) is a highly reactive, hardened compound having a non-aromatic carbon-carbon double bond or a carbon-carbon triple bond and a diacetylene bond in the molecule. It is a sexual compound.

In the present invention, R and R' are unsaturated hydrocarbon groups having the same or different double bonds or triple bonds having 2 to 8 carbon atoms, and examples thereof include ct+z=c-1CH3=
CHCHz-, CH3CH=CH-, CH3CH=CH
, C11, CH3 CH3CHzCHzCH=CH-, CH3CH=C-1
CH3CH=CCH2CH=CH CB.

etc. Among these, the following are preferred in that they have good reactivity, are less likely to cause drastic decomposition, and have excellent properties after curing. 0 In the present invention, x and x' are -0C- or -0-, and -0C- is particularly preferred from the viewpoint of reactivity, resistance to rapid decomposition, and good properties after curing.

In the present invention, the method for synthesizing R-χ-CH, -CmiCC=CCHz Showa 6
A method such as that disclosed in Japanese Patent No. 2-267251 can be applied.

In the present invention, the polymer of the diacetylene compound is a dimer or more in which the double bonds of the diacetylene compound represented by the general formula (I) are mainly reacted, and in some cases, the diacetylene groups of the moiety are also reacted. It is a polymer of
Solid phase polymerization, photopolymerization, etc. can be applied.

In bulk polymerization, the diacetylene compound can be synthesized, for example, by heat treatment for a certain period of time under an inert atmosphere. The reaction temperature is preferably in the range of 50 to 250°C, more preferably 80 to 140°C. The reaction time is not particularly limited, but is preferably between 5 minutes and 24 hours.

In solution polymerization, the diacetylene compound is added to water or a general-purpose organic solvent, and if necessary, benzoyl peroxide, acetyl peroxide, 2,2'-azobisisobutyronitrile, t-butyl hydroperoxide, It can be synthesized by reaction in the presence of cumene hydroperoxide or the like. There are no particular restrictions on the reaction temperature and reaction time, but the reaction temperature is 50 to 200°C, and the reaction time is 5 minutes to
It is 24 hours.

In suspension polymerization, the diacetylene compound can be synthesized by reacting the diacetylene compound in water and an organic solvent that is immiscible with water, if necessary, in the presence of a peroxide, perester, or redox initiator.

There are no particular restrictions on the reaction temperature and reaction period, but the reaction temperature is preferably 0°C to 100°C, and the reaction time is preferably 1 minute to 24 hours.

Emulsion polymerization can be achieved by adding a certain amount of anionic, cationic, or nonionic surfactant to the suspension polymerization system. There are no particular limitations on the amount and type of surfactant to be added.

In addition, for the synthesis of the diacetylene compound polymer of the present invention,
Ionic polymerization methods such as anionic polymerization, cationic polymerization, and coordination polymerization are also applicable.

The diacetylene compound polymer of the present invention is a diacetylene compound polymer represented by formula (1), and there are no limitations on its degree of polymerization, molecular weight, and molecular weight distribution as long as it is a dimer or more. However, methanol, ethanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, tetrahydrofuran, cyclohexane, dinoxane,
It is preferable that it is soluble in at least one organic solvent such as diethyl ether, toluene, xylene, chloroform, dimethyl sulfoxide, N,N'-dimethylacetamide, or the diacetylene compound represented by formula (1).

In particular, a product in which the diacetylene compound is partially polymerized and a polymer of the diacetylene compound is mixed with the diacetylene compound is preferably used in the present invention, and has a viscosity of 10 centipoise or more at 25°C, for example. A mixture having a concentration of 20 centipoise or more is preferable, and a mixture having a concentration of 20 centipoise or more is more preferable.

In the present invention, when impregnating a nonwoven fabric with the diacetylene compound and a polymer of the diacetylene compound (hereinafter abbreviated as diacetylene compound), the diacetylene compound can be used in a liquid state. Moreover, it can be dissolved in an organic solvent and used in a solution state, or emulsified and used in an emulsion state.

Examples of the organic solvent used here include methanol, ethanol, acetone, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, tetrahydrofuran, dioxane, diethyl ether, toluene, xylene, and cyclohexane.

These liquids, solutions, or emulsions impregnated into the nonwoven fabric may contain other additives, such as curing accelerators and inhibitors, dyes, ultraviolet absorbers and stabilizers, flame retardants, and preservatives, as necessary. Agents, insect repellents, etc. may be added. Furthermore, inorganic substances such as calcium carbonate, talc, titanium oxide, clay, silica, and glass powder can be added as fillers.

In the present invention, the diacetylene compounds can be used in combination with other reactive monomers, polymers thereof, thermosetting resins, and thermoplastic resins. Even in that case, the diacetylene compounds have excellent permeability into the inside of the nonwoven fabric,
This exhibits an effect consistent with the purpose of the present invention.

In the present invention, the method of impregnating the nonwoven fabric with the diacetylene compounds includes, for example, a normal pressure dipping method in which the nonwoven fabric is immersed in an impregnating liquid under normal pressure, a nonwoven fabric is immersed in an impregnating liquid under reduced pressure, and then the nonwoven fabric is immersed in an impregnating liquid under normal pressure or The reduced-pressure normal pressure method or reduced-pressure processing method involves immersing the non-woven fabric under pressure; the reduced-pressure method involves applying the impregnating liquid on one side of the fabric and suctioning it under reduced pressure from the other side; A compression method that utilizes restoring force can be used, and is appropriately selected depending on the amount of impregnation, the type and shape of the nonwoven fabric, etc.

When a solvent is used, after impregnation, the nonwoven fabric is dried to volatilize the solvent, and then the diacetylene compounds are cured.

As a method for removing the solvent by volatilization, air drying, forced drying using hot air or hot air, drying in a reduced pressure atmosphere, etc. are used.

In the present invention, methods for curing diacetylene compounds include heating methods, ultraviolet irradiation methods,
Various methods can be selected, such as a method using radiation or electron beam irradiation, or a method combining two or more of these methods, such as curing the surface portion with ultraviolet irradiation and then heating.

Since the curing of the diacetylene compounds of the present invention is unlikely to be inhibited by air, the atmosphere during curing is air,
Various methods can be selected, such as in an inert gas, reduced pressure, or increased pressure.

When curing is carried out by heating, the heating temperature is from 60°C to 260°C, preferably 240°C, and the curing temperature can also be adjusted by using various initiators as curing accelerators. Examples of such initiators include commonly used organic peroxides, azo compounds, redox initiators, etc. For example, peroxides such as benzoyl peroxide and methyl ethyl ketone peroxide, 2.2' azo bis Butyronitrile, azo-2,4
Examples include azo compounds such as -dimethyl-4-methoxyvaleronitrile, and redox initiators such as a combination of benzoyl peroxide or methyl ethyl ketone peroxide with aniline or cobalt naphthenate.

Further, when photocuring is performed, a photopolymerization initiator such as benzoin ethers, benzophenones, acetophenones, thioxanthone compounds, etc. can be used in combination. However, since the diacetylene compounds used in the present invention have extremely high curing reactivity, it is preferable to keep the use of these curing accelerators to a minimum so as not to cause a rapid curing reaction.

In the diacetylene resin-impregnated nonwoven fabric of the present invention thus obtained, the diacetylene resin, that is, the diacetylene compounds of the present invention or a cured product of the diacetylene compounds, generally has a resin retention rate of 0.3. %~250%
, preferably 0.5% to 180%. Here, the above-mentioned resin retention rate is the weight ratio of the resin to the nonwoven fabric of the resin-impregnated nonwoven fabric, that is, the value calculated by the following formula.

YI: Absolute dry weight of resin-impregnated nonwoven fabric Y: Absolute dry weight of untreated nonwoven fabric When the diacetylene resin-impregnated nonwoven fabric of the present invention is used, it can be used alone or in combination and/or mixed with other materials to form various It can be molded into products with different shapes and forms. Such a material can be used alone as a nonwoven fabric with modified properties, such as a plate material, or as an integrated cured molded body of a single-weight laminate. In addition, inorganic and organic fiber materials such as carbon fiber and aramid fiber, composite materials laminated or mixed with these cloths, nonwoven fabrics, and prepregs, and composites with inorganic powders such as ceramics and polymer powders, etc. Its applications are wide-ranging, including composite materials with carbon whiskers and ceramic whiskers.

When molding such molded bodies and composite materials, it is extremely preferable to further use the diacetylene compounds of the present invention as a bonding material or as a matrix resin, and the excellent properties of the diacetylene compounds of the present invention Because the performance is taken advantage of, the resulting material has excellent properties that could not be achieved with conventional materials, paving the way for its use as a high-performance material in nonwoven fabrics.

〔Example] Next, the present invention will be specifically explained with reference to Examples.

Reference Example I CHz=CH-Coo-CTo-C=C-C=C-CH
Synthesis of z-00C-CHzCHz (compound (a)) CHz=CH-COO-CHz-C= CH2mol
with 0.2■O2 of cuprous chloride and 300jll of pyridine.
The reaction was allowed to proceed for 5 hours while blowing oxygen. After the reaction, the reaction mixture was poured into cold concentrated hydrochloric acid, extracted with ether, dried over sulfur salt, concentrated, and the compound (a) in the liquid field was extracted.
I got it.

The structure of the obtained compound was confirmed by IR and NMR spectra.

Adding a small amount of activated carbon to the compound (a) synthesized in this way,
After adding ether, mixing and filtration, the ether was distilled off and concentrated under reduced pressure. Then, a small amount of hexane was added thereto, and the solution was left at -15°C or lower. The obtained solid was filtered under cooling to obtain highly pure compound (a).

Reference Example 2 Compound (a) obtained in Reference Example 1 was heated at 100°C for 60 minutes in a nitrogen gas atmosphere, and the viscosity (25°C) was 30
A solution (b) containing 15% centipoise polymer was obtained.

Reference example 3 CH2・C-C0O-CHz-C= C-C= C-C
Hz-00C-C=CHz (C)1.
CH.

Synthesis of hardware (C)) CHz=C(C1h)COOCHzC=CH1mol!
20Oad of pyridine with 0.15mof cuprous chloride
After 4 hours of reaction while blowing oxygen inside,
After pouring the reactant into cold concentrated hydrochloric acid and performing ether extraction,
After drying with glass salt and concentrating, a liquid compound (C) was obtained.

The structure of the obtained compound was confirmed by IR and NMR spectra.

Adding a small amount of activated carbon to the compound (C) synthesized in this way,
After adding ether, mixing and filtering to remove impurities, the ether was distilled off. Thereafter, highly pure compound (C) was obtained by reprecipitation from hexane.

Reference example 4 Synthesis of (compound (d)) Compound (d) was obtained by the same operation as in 1.

Reference example 5 CHz=CHCHzOCHzC= C-CN C-CH
Using CIh=CB-CHzOCHzC=CH as a raw material for the synthesis of zOCHzCH=CH (compound (e)), it can be synthesized in the same manner as in Reference Example 1.

Examples 1 to 4 A web made of polyacrylonitrile fibers with a fineness of 2.0 denier and a fiber length of 60 denier was needle-punched to 30 denier.
A nonwoven fabric having a three-dimensional structure with a specific gravity of 0.09 and a specific gravity of 0 g/rrf was obtained. This nonwoven fabric was cut into a square of 30 squares on each side to prepare a test piece. Place this test piece in a desiccator and
The pressure was maintained at 0 mHH, and the treatment liquid shown in Table 1 was injected into it, and then the pressure was returned to normal and left for 24 hours. This resin-impregnated nonwoven fabric was cured (polymerized) by heating in a pressure oven at 100°C for 24 hours to obtain a cured resin-impregnated nonwoven fabric. The properties shown in Table 1 were measured for the obtained materials. It can be seen that the resin-impregnated nonwoven fabric of the present invention exhibits excellent properties in all physical properties. In addition, unlike the comparative example, the cured resin-impregnated nonwoven fabric of the present invention does not contain hexane, benzene,
It was completely unaffected by solvents such as gasoline, kerosene, acetone, chloroform 1, dimethyl sulfoxide, 10% hydrochloric acid, and 5% aqueous sodium hydroxide solution.

(Margins below) Examples 5 to 8 Instead of the nonwoven fabric used in Examples 1 to 4, stretched and crimped 2.0 denier nylon single fibers (5.0 cm
) is made into a random web and subjected to needle punch processing,
Weight 300g/rr? A nonwoven fabric having a thickness of about 2.5 trm was obtained. This nonwoven fabric was cut into a square with a side of 30 mm to obtain a test piece. Place this test piece in a desiccator and
The pressure was maintained at a reduced pressure of 1ttg, and the treatment liquid shown in Table 2 was poured into it, and then the pressure was returned to normal and left for 24 hours. This resin-impregnated nonwoven fabric was cured (polymerized) by heating for 1 hour in a pressurized open state at 130°C to obtain a cured resin-impregnated nonwoven fabric. Regarding the obtained material, each physical property shown in Table 2 was measured. It can be seen that the resin-impregnated nonwoven fabric of the present invention exhibits excellent properties in all physical properties. In addition, unlike the comparative example, the cured resin-impregnated nonwoven fabric of the present invention does not contain hexane, benzene,
It was completely unaffected by solvents such as gasolin, kerosene, acetone, chloroform, dimethyl sulfoxide, 10% hydrochloric acid, and 5% aqueous sodium hydroxide solution.

Examples 9-12 Except that compound (e) was used instead of compound (a),
Examples 1-4 were repeated. The results are shown in Table 3. In any physical property, the resin-impregnated nonwoven fabric of the present invention has
It can be seen that it exhibits excellent characteristics. Furthermore, unlike the comparative examples, the cured resin-impregnated nonwoven fabric of the present invention is not attacked by solvents such as hexane, benzene, gasoline, kerosene, acetone, chloroform, dimethyl sulfoxide, 10% hydrochloric acid, and 5% sodium hydroxide aqueous solution. Ta.

(Blank below) [Effects of the Invention] The nonwoven fabric impregnated with the diacetylene compounds of the present invention has excellent permeability of the diacetylene compound and excellent reactivity of the diacetylene bonds and unsaturated bonds, so that the inside of the nonwoven fabric can be easily absorbed. It adheres and bonds well to single fibers, and furthermore, due to its good curing reactivity, it has the ability to harden the entire nonwoven fabric densely and integrally. Therefore, the diacetylene resin-impregnated nonwoven fabric before curing of the present invention can be used for single-weight laminate molding, compression molding of small piece materials and cotton-like materials, etc., and the diacetylene resin-impregnated nonwoven fabric after curing is extremely It has characteristics such as high rigidity and hardness, light weight, and dimensional stability. Moreover, since the above properties can be exhibited with a small amount of resin impregnation, the nonwoven fabric impregnated with diacetylene resin of the present invention can be used as a reinforced plastic material by taking advantage of these excellent properties. It can be used for lightweight structural materials and precision mechanical parts, and is extremely useful as industrial materials such as electrical insulation materials, printed wiring boards, and various coated cloths.

Claims (1)

[Claims] 1. A resin-impregnated nonwoven fabric obtained by impregnating a nonwoven fabric with a diacetylene compound represented by formula (1) and/or a polymer of the diacetylene compound. R-X-CH_2-C≡C-C≡C-CH_2-X'-
R'......(I) (However, R and R' are unsaturated hydrocarbon groups having 2 to 8 carbon atoms, and X and X' represent an ester bond or an ether bond.) 2. Impregnating a nonwoven fabric with a diacetylene compound represented by formula (I) and/or a polymer of the diacetylene compound,
Resin-impregnated nonwoven fabric made by curing. R-X-CH_2-C≡C-C≡C-CH_2-X'-
R'......(I) (However, R and R' are unsaturated hydrocarbons having 2 to 8 carbon atoms, and X and X' represent ester bonds or ether bonds.)