JPH02169656A - Low-shrinkage phenol resin molding material - Google Patents

Abstract

PURPOSE:To prepare a molding material which has a low initial viscosity, improved aging characteristics, and improved shrink properties after molding, and which requires only a short time to attain a necessary viscosity increase by compounding a resol-type phenol resin with a specific cure regulator, a specific filler and a specific lactone. CONSTITUTION:20-60wt.% (based on the total compsn.; the same applies hereunder) resol-type phenol resin 0.1-15wt.% cure regulator comprising alkaline earth metal oxides or hydroxides, pref. a mixture of CaO or Ca(OH)2 with MgO or Mg(OH)2, or a silane (e.g. gamma-aminopropyltriethoxysilane), 5-60wt.% filler with an oil absorption (JIS K-5101, linseed oil method) of 15-50mg/100g, pref. 17-34mg/100g [e.g. CaCO3, Al(OH)3, or BaS], and 0.1-10wt.%, pref. 2.5-5wt.%, lactone of the formula (wherein X is halogen, m is 0 or 1, n is 2-4, and m+n is 2-5) (e.g. gamma-butyrolactone) are compounded.

Description

[Detailed Description of the Invention] [Industrial Applications] The present invention relates to a low-shrinkage phenolic resin molding material that hardens in neutral to alkaline conditions, and particularly relates to an improved coating material based on a resol type phenolic resin. and a sheet molding material having aging properties.

[Conventional technology]

A phenolic resin molding material obtained by mixing a phenol-formaldehyde resin with a filler can be cured into a container and can become a durable molded product. Such a phenolic resin molding compound used to obtain molded articles is disclosed in US Pat. No. 2,424,787. This patent discloses the use of both "-cast resins" or resol resins and "two-stage resins" or novolak resins in the production of phenolic resin molding materials. discloses that because the resin is liquid it is necessary to mix the resin syrup with fillers.According to a preferred embodiment of that invention, alkali metal or alkaline earth containing compounds of calcium and magnesium are disclosed. It is disclosed that oxides of similar metals are preferably incorporated into molding materials consisting of phenolic resins and fillers. Magnesium oxides are mentioned as being particularly advantageous. Such oxides are incorporated into molding materials. A hardening reaction of the molding material takes place at room temperature or slightly higher temperature. However, this hardening does not convert the resin to the final infusible, insoluble step; the hardened product is heated and It is easily molded under pressure to give a satisfactory molded product.

In U.S. Pat.
The use of a resol type phenol formaldehyde resin molding material in SMC) technology is disclosed. The Phillips patent discloses molding materials that include fillers, compounds such as calcium and magnesium hydroxides, mold release agents, and coupling agents.

U.S. Pat. No. 3,956,227 discloses a phenolic resin molding material containing a cement containing calcium oxide, and also discloses the use of a silane coupling agent. Sheet molding materials are disclosed by said patents. Related patents include U.S. Patent Nos. 3.944,515 and 3.988.2119.

A later patent, US Pat. No. 4,182,701, relates to phenolic resin molding materials made by mixing and reacting phenol and aldehydes with calcium hydroxide and a silane coupling agent.

The use of calcium hydroxide and magnesium hydroxide during the reaction of phenolic resins is also described in U.S. Patent No. 4.070,
No. 331.

U.S. Patent No. 4.11 to Olivo (Of 1 vo) et al.
No. 6.921 discloses phenolic resin molding compositions made from formaldehyde and bisphenol. The patent discloses the use of calcium oxide or hydroxide in the molding material.

Also disclosed is the use of hollow carbon and hollow phenolic microballoons.

British Patent No. 1.38 by Farkas
No. 3,227 discloses a sheet molding material made from a glycol-modified resol type phenolic aldehyde resin. This resin is cured with acid. U.S. Pat. No. 4,419,400 discloses oligomer-modified resins.

Several patent applications published in Japan cover this technology. Japanese Patent Publication No. Sho 61-15887 discloses a sheet molding material containing a resol type phenolic resin, calcium hydroxide or oxide and/or magnesium hydroxide or oxide, and a filler such as talc or clay. JP-A-58-91935 discloses that phenolic resin molding materials containing resol-type phenolic resins, thickeners, fillers and reinforcing agents such as calcium oxide or hydroxide and magnesium oxide or hydroxide are used in brake shoes. It is used in combination with an abrasive. Sheet molding material technology is used to form this brake shoe.

JP-A-59-170126 discloses a sheet molding material obtained by impregnating a special shaped continuous or discontinuous glass fiber with a resol type phenolic resin and an alkaline earth metal oxide or hydroxide. ing.

Furthermore, in JP-A No. 62-96556, a filler consisting of (a) a resol type phenolic resin, (b) an alkaline earth metal hydroxide or oxide, or a silane compound, and (c) clay and talc is disclosed. A phenolic resin molding material is disclosed which is characterized in that it contains a mixture or microspheres.

Furthermore, JP-A No. 63-291945 discloses (a) a resol plastic phenolic resin, (b) a curing agent selected from the group of alkaline earth metal hydroxides or oxides, and silane compounds, and (c) a filler. A low-shrinkage phenolic resin molding material is disclosed, which is characterized by comprising a lactone, and (d) a lactone.

[Problem to be Solved by the Invention] Commercially available sheet molding materials, whether polyester, phenol formaldehyde resin, or other resin, have a typical formulation, and are mixed at a relatively low viscosity to facilitate mixing. . It is particularly desirable to have as low a viscosity as possible during stirring so that large amounts of relatively inexpensive fillers can be added.

It is also important that the thickening after mixing be relatively fast in order to minimize ripening time.

The aforementioned Japanese Patent Application Laid-open No. 62-96558 and Japanese Patent Application Laid-Open No. 63-291
With the clay and talc fillers used in No. 945, the viscosity of the mixed molding material is extremely high. For this reason, impregnation into the fiber reinforcing material is poor, making it difficult to obtain a uniform sheet molding material, and having a negative effect on physical properties.

Additionally, an inert diluent can be added to lower the initial viscosity. However, such a diluent has an adverse effect on the aging effect as well as on the physical properties of the final sheet forming material.

After mixing, the material is combined with fiber reinforcement material and formed into a sandwich-type sheet between two polymer films. The polymer film is removed before the sheet material is formed into its final shape.

Generally, phenolic resin molding materials are aged in an oven at 30-60° C. for several days before the film can be peeled off. It is therefore an object of the present invention to have a relatively low initial viscosity and improved aging properties.
Another object of the present invention is to provide a low-shrinkage phenolic resin molding material that requires a short thickening time.

In general, molding materials based on phenolic resins have inferior dimensional stability after molding than molding materials based on polyester resins because the curing process is a condensation reaction.However, in the molding material of the present invention, lactones The second objective is to provide a phenolic resin molding material with significantly improved shrinkage properties.

Furthermore, since general phenolic resin molding materials contain acidic substances as hardening agents, they have the major drawback of corroding the mold during molding, but the molding material of the present invention combines resol type phenolic resin and hardenability adjustment. A third object of the present invention is to provide a phenolic resin molding material that does not corrode the mold because it is cured in neutral or alkaline conditions without using an acidic curing agent by selecting a suitable curing agent.

[Means for Solving the Problems] A neutral to alkaline curing type low shrinkage phenolic resin molding material particularly useful as a sheet molding material according to the present invention is composed of the following components.

(a) resol type phenolic resin; (b) curing modifier selected from the group consisting of alkaline earth metal oxides or hydroxides and silane compounds; (c) calcium carbonate, aluminum hydroxide, barium sulfate. A filler, which is a filler alone or a mixture of two or more, and (d) a lactone having the following structural formula, (wherein, X is a halogen, m is O or L, n is 2 to 4,
(m+n is 2 to 5) Furthermore, this molding material generally contains a mold release agent, a coupling agent,
Additives such as pigments are also added as necessary.

The molding material of the present invention is preferably used in a sheet molding method, a pultrusion method, a filament winding method, etc. in combination with reinforcing fibers such as glass fibers or filaments.

Resol type phenolic resins useful in the practice of this invention are generally prepared by reacting phenol with an excess molar ratio of aldehyde in the presence of an alkaline catalyst.

Examples of phenols that can be used in the preparation of the resole-type phenolic aldehyde resins used in the practice of this invention include 6- to 24-carbon carbon atoms such as phenol itself (c6H50H), naphthol, anthranol, and substituted derivatives thereof. Included are aromatic compounds having ortho- and para-configured hydroxy or amino groups with atoms. And the substituents on the aromatic compounds of the substituted derivatives include hydrogen, halogens such as CI, Br and F, NF2
and hydrocarbon groups such as:

(a) alkyl groups of 1 to 12 carbon atoms, preferably 1 to 9 carbon atoms, and their various isomers, which are substituted in the ortho or para position of the aromatic nucleus; b) cycloalkyl groups of 5 to 12 carbon atoms such as cyclohexyl, cyclopentyl, methylcyclohexyl, butylcyclohexyl, etc.; (c) arylketone groups in which the hydrocarbon moiety is defined in (e) below; (d) a) alkyl, aryl and cycloalkyl carboxyl groups in which the hydrocarbon moiety is defined in (a) and (b) above; (e) aryl groups of 6 to 24 carbon atoms such as phenyl, naphthyl, anthryl, etc. , (f) an aryl-substituted alkyl group in which the aryl group is a phenyl group containing lower alkyl and/or hydroxy substituents (the resulting hydroxyaromatic is, for example, a bisphenol); (g) an oxy corresponding to the aforementioned hydrocarbon group; and (h) a mixture of the aforementioned hydroxyaromatics.

Suitable substituted phenols include m-cresol, m-propylphenol, m-isobutylphenol, m-5
ee-butylphenol, m-tert-butylphenol, m-bromophenol, m-chlorophenol,
m-phenylphenol, m-benzylphenol, m
- cetylphenol, m-cumylphenol, m-hydroxyacetophenone, m-hydroxybenzophenone, m-d-limonenephenol. Corresponding phenols substituted in the ortho and para positions may also be used to some extent, but are not preferred.

Mixtures of the various hydroxyaromatic compounds mentioned above may also be used.

Among the phenols that can be used are those known as "cresylic acids," which are often heterogeneous compounds with more than one reactive hydrogen position, i.e. unsubstituted at the ortho and para positions. It contains a mixture and produces a relatively less reactive resin. These compounds contain 3
．． 5-xylenol, m-cresol, 3.4-xylenol, 2.5-xylenol, 2.3-xylenol, phenol, p-cresol, 0-cresol, 2.
Includes 4-xylenol and 2,6-xylenol.

Cresylic acid or tar acid includes phenol and its congeners, ie, high boiling substances such as cresol, xylenol, trimethylphenol, ethylphenol, and dihydroxyphenol, polycyclic phenols, and the like. They are often obtained from the low temperature trimerization of cracked gases such as coal, lignite, or from conventional high temperature coke oven tars, or from the liquid products of thermal and catalytic petroleum cracking, shell oils, coal hydrogenation products, etc.

Polyhydroxy aromatic compounds such as resorcinol may also be used.

Mixtures of aniline and phenol are also useful in the present invention because they react with aldehydes or ketones to form resols.

Mixtures of urea and phenol are also useful as they react with aldehydes or ketones to form resols.

Within the scope of the present invention, aldehydes that can be used to produce resols include formaldehyde or its modifications such as formalin in a concentration of 37% or more, or balaldehyde, acetaldehyde, propionaldehyde, isobutyraldehyde, isobutyraldehyde, Contains bentaldehyde, etc. Aldehydes with more than 8 carbon atoms are unsuitable since they have an unfavorable effect on resinification. Preferred aldehydes are those having 1 to 4 carbon atoms, such as formaldehyde, which may be in an aqueous solution (37% or more) or in the form of a lower polymer such as paraformaldehyde or trioxane. Other aldehydes include balaldehyde, furfural, 2
- Ethylhexanal, ethylbutyraldehyde, heptaldehyde, benzaldehyde and crotonaldehyde.

The alkaline catalyst used in the preparation of the resol resin used in the present invention may be any known to those skilled in the art.

For example, sodium hydroxide and calcium hydroxide. Generally, in the preparation of alkali metal hydroxides, alkaline earth metal hydroxides, ammonium hydroxide, resols, the molar ratio of aldehyde to phenol is preferably from about 1.1:1 to 2.5:l. be. Generally, the reaction mixture is gradually heated to reflux and maintained at about 60° C. to reflux temperature until less than about 2% free aldehyde is present.

The reaction mixture is then cooled and, if necessary, the catalyst is neutralized with an acid such as glacial acetic acid or sulfuric acid. The pH is adjusted to approximately 5-8. The resin is then dehydrated to a solids content of about 60 to 80
%.

The molding material of the present invention comprises a resol-type fluorinated alkaline earth metal compound, especially oxides and hydroxides of magnesium, calcium, and barium, and a silane compound, especially aminoalkylsilane.

Commercially useful silanes are γ-aminopropyltriethoxysilane and N-β(aminoethyl)γ-aminopropyltrimethoxysilane.

Preferred alkaline earth metal compound hardeners are magnesium and potassium oxides and hydroxides, and especially mixtures thereof.

In preparing sheet molding materials, the resin formulation is cast onto a moving sheet of plastic film. Controlling the viscosity of the resin compound at this time is very important in terms of work.

It has been found that the use of calcium oxide or hydroxide results in rapid curing of the sheet molding material. When only hydroxide or magnesium oxide is used, the curing rate is slow. The use of mixtures of calcium oxide or hydroxide and magnesium oxide or hydroxide provides very good control of the viscosity of the molding material, also called treatment compound, on the moving sheet. For this purpose, a preferred mixture of calcium oxide or hydroxide and magnesium oxide or hydroxide has a weight ratio of calcium hydroxide or oxide to magnesium hydroxide or oxide in the range of about 1O:1 to 0.1:10. . The curing agent is preferably from 0.1 to about 1
Used at 5% by weight.

The filler used in the sheet molding material of the present invention is about 5 to 60% by weight, based on the molding material.

Specifically, the filler used in the present invention is calcium carbonate, aluminum hydroxide, barium sulfate alone or in a mixture of two or more, and in combination with these fillers, clay, talc, and microspheres alone or in combination. It can also be used in combination with a filler that is a mixture of more than one type of filler. In addition to this,
As auxiliary inorganic or organic fillers, fillers such as those customary for phenolic resin molding materials are used.

Suitable such materials include silicates, aluminates, carbides, carbons, carbonates, metals, rocks, minerals, sulfates, oxides, micas, wollastonites, and the like.

Fillers are mixed; they have a significant influence on the viscosity of the molding material. In particular, when talc or clay is used, the viscosity of the material increases rapidly, impregnating the fiber reinforcing material becomes poor, and it is difficult to obtain a uniform sheet molding material. On the other hand, if a mixture of talc and calcium carbonate, talc and aluminum hydroxide, etc. is used, viscosity control becomes better.

In this case, the oil absorption amount of the filler powder greatly influences the viscosity of the molding material. The oil absorption amount (JIS K-5101 linseed oil method) is suitably 15-50 mg/loOg, preferably 17-34 mg/long. When this oil absorption amount is less than 15 mg/100 g, the particle size of the filler is too coarse and it is difficult to obtain a smooth molding material. 50 mg/
If it exceeds 100 g, the viscosity of the molding material will be high and a uniform molding material will not be obtained.

Lactones such as butyrolactone are used as reactive diluents in the materials of the invention. Lactones reduce the initial viscosity, that is, the viscosity during the mixing process, and promote the increase in viscosity during the ripening process. When lactone is mixed into the molding material, a large amount of relatively inert and inexpensive filler can be added. Furthermore, the use of lactones in the molding materials of the invention provides high impact strength and low shrinkage.

The lactones used in the present invention are represented by the following structural formula.

Here, X is halogen, m is 0 or l, n is 2 to 4, m
+n is 2 to 5. Generally, lactones include δ-valerolactone, butyrolactone, bromobutyrolactone, and the like. Butyrolactone is a preferred lactone in terms of price, availability, boiling point range, and other properties.

The amount of lactone incorporated in the molding material of the present invention can be varied considerably depending on the desired viscosity. Normally, the amount of lactone added is about 0.0% to the sheet molding material, pultrusion or filament winding molding material.
1 to about 10% by weight, preferably about 2.5 to about 5% by weight.

Mold release agents commonly used in phenolic resin molding materials are used in the formulations of the invention. Among these are stearic acid and its metal salts, such as the zinc, calcium and magnesium salts of stearic acid. Organic compounds such as glycerol monostearate may also be used.

The molding material of the present invention contains approximately 0.0% relative to the molding material in order to improve the strength properties and fiber reinforcement effect. It may contain a silane coupling agent in an amount of 1 to 10% by weight. Suitable coupling agents for this purpose are known in the art, for example tetraethyloxysilane, γ
-aminoalkylsilanes such as -aminopropyltriethoxysilane and gamma-aminopropyltrimethoxysilane.

The phenolic resin molding composition of the present invention is used for producing bulk or sheet molding compositions by mixing resin with inert fibers and/or fillers. Typical inert fibers suitable for obtaining a reinforced final product are glass fibers with lengths of 1.5 to 50 mm. The resins of the present invention are particularly suitable for use with glass lengths and fibers, particularly because they can produce high strength products. The length of the long glass fibers is generally about 12 to 50 degrees. Other inorganic and organic fibers include carbon, graphite, ceramics,
Includes polyester, aramid and polyacrylonitrile fibers. The reinforcing inert fibers are preferably used in an amount of about 5 to 60% by weight based on the molding material.

The sheet molding materials of the present invention are prepared using resins, fillers, inorganic or organic fibers, and other additives as described below. The resin is mixed with an inorganic filler containing a divalent base to form a treatment formulation. The treatment formulation is cast onto a first sheet of thin plastic sheet or film such as polyethylene, polyester, polypropylene, etc.

A layer of chopped fiber is superimposed on the layer formed on the first sheet. The viscosity of the treatment formulation is adjusted so that it can be cast onto the sheet to form a layer of uniform thickness and adequately wet the fibers. - The viscosity of processing formulations for sheet molding materials is generally between s, aaa and r at 33°C.
oo, ooo centipoise. A second layer of treatment formulation is placed on top of the fibrous layer and its surface is covered with a second plastic sheet. The resulting composite material is passed between a series of rolls to form a mechanically handleable sheet forming material.

The resulting material is rolled up and stored in a warm room at 20-70° C. for 20-100 hours or more to form a peelable, moldable sheet molding material.

The resulting molding material can be easily molded at high temperatures to produce a variety of products such as structural panels used in the transportation and construction industries.

The molding materials or processing formulations of the present invention are particularly useful for preparing sheet molding materials with improved aging times. However, this molding material can also be used in bulk molding, filament winding, continuous layer molding, ram injection molding,
It is also useful for transfer molding, etc.

LExample J The present invention will be described below with reference to Examples. However, the present invention is not limited to these examples. Further, all "parts" and "%" described herein indicate "parts by weight" and "% by weight" unless otherwise specified.

Examples 1 to 5 Each sheet molding material was prepared as follows:
.

First, talc (manufactured by Matsuzai Sangyo), kaolin (manufactured by Hayashi Co., Ltd.)
, calcium carbonate (Nitto Powder Chemicals Department), aluminum hydroxide (manufactured by Showa Denko), zinc stearate, calcium hydroxide and magnesium oxide in the proportions shown in Table 1, V
The mixture of fillers was obtained by mixing in a mold mixer for about 30 minutes. .

Resol type phenolic resin (PR-53 manufactured by Sumitomo Durez)
674), a silane coupling agent (
γ-aminopropyltriethoxysilane) and butyrolactone were mixed in a high speed mixer to prepare a resin mixture.

While adding the filler to the resin mixture, the viscosity of about 8 to 10 was measured and the values were as shown in Table 1. The mixture was cooled to room temperature (approximately 22° C.) and samples were taken to check for viscosity increase over several days.

The above resin mixture was combined with 30% of 25 mm glass mlacOcF (manufactured by mlacOcF) using a small SMC molding machine and formed into a sandwich-type sheet between two polymer films.

The film was incubated at about 45° C. for 2-3 days until it could be peeled off.

Next, compression molding was carried out into a 30 cm square flat plate at a mold temperature of 150° C. and a pressure of 100 kg/c for 3 minutes to obtain a molded flat plate having a thickness of 311II11 and a specific gravity of 1.8.

Regarding the obtained molded flat plate, the shrinkage rate with respect to the cold dimension of the mold was measured, and the molded flat plate was cut and its bending strength was measured according to the JIS standard method.

The results of these measurements are shown in Table 1.

Comparative Examples 1-2 Comparative Examples 1 and 2 were conducted in the same manner as in the examples except that butyrolactone was not added and talc or kaolin was used as a filler.

The results are shown in Table 1.

Comparative Example 3 Prepared based on the description in Japanese Patent Publication No. 61-15887,
The results are shown in Table 1.

〔Effect of the invention〕

According to the invention, the initial viscosity is relatively low, the aging properties are improved, and the thickening period required is short.

A low-shrinkage 7-enol resin molding material that does not corrode the mold during molding and has high bending strength after molding can be obtained.

This molding material is particularly useful as a sheet molding material with an improved aging period, allowing efficient production of products such as structural panels used in the transportation and construction sectors, for example.

Procedure support device (voluntary) 1989

Claims (1)

[Scope of Claims] 1. (a) resol type phenolic resin, (b) hardening modifier selected from the group consisting of alkaline earth metal oxides or hydroxides and silane compounds, (c) calcium carbonate. , a filler that is aluminum hydroxide, barium sulfate alone or a mixture of two or more, and (d) a lactone having the following structural formula, ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, m is 0 or 1, n is 2 to 4,
m+n is 2 to 5) A low shrinkage phenolic resin molding material. 2. The molding material according to claim 1, wherein the filler is a filler consisting of clay, talc, and microspheres alone or in combination with a mixture of two or more thereof. 3. The molding material according to claim 1 or 2, wherein the filler has an oil absorption amount (JIS K-5101 linseed oil method) of 15 to 50 mg/100 g. 4. The molding material according to claim 1, wherein the hardening modifier is a mixture of calcium oxide or calcium hydroxide and magnesium oxide or magnesium hydroxide. 5. The molding material according to claim 1, which contains a fiber reinforcing material.