JPS5870760A - Binder for glass short fiber and production of glass short fiber mat - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a binder for short glass fibers and a method for producing short glass fibers.

Glass short fiber mats are manufactured by adding a binder to short glass fibers produced by centrifugal method, flame method, etc., depositing them on a moving perforated conveyor to a predetermined thickness, and binding the short glass fibers with a binder. be done.
In the production equipment, the binder is added to the short fibers in a state containing a large amount of water to the short glass fibers, which are kept at a high temperature in a high temperature atmosphere immediately after being produced. Since the binder is heated by the high-temperature atmosphere and short glass fibers, most of the moisture contained in the binder is evaporated, and the short glass fibers are lightly bonded to each other by the uncured solid content of the binder. It is formed from mats (referred to as raw mats).

The raw mat is sent to the next processing step and used as raw material for various products. For example, by heating a green mat while pressing it between a pair of molds, ceiling panels, heat insulating materials for vehicles, etc. are manufactured. When thermoplastic resin is used as a binder,
If the resulting product is used at high temperatures, it will undergo plastic deformation, so thermosetting resins are exclusively used as binders, but green mats made with thermosetting resins have a short usable life and are advantageous. There are disadvantages such as the lack of flexibility in the manufactured products.

Raw mats are sometimes sent to continuous processing immediately after production, but are often sent to another factory for use after being packaged. In this case, the green mat deteriorates over time after its manufacture, and if a degradable mat is used, delamination occurs, making it impossible to obtain a product with sufficient strength.

The elapsed time from the production of the raw mat to the use of the raw mat to obtain a product with sufficient strength without deterioration of the raw mat (
The shelf life of raw mats varies depending on the storage conditions of the raw mats, but it is usually about a few days, so raw mats need to be produced in small quantities according to the amount of use, packed and transported. If the storage period becomes too long due to a malfunction in the processing process, etc., raw mats become unusable, and there is a strong demand for the development of raw mats with a longer usable life.
Until now, such raw mats were unknown.

As a result of repeated studies to solve this proposition, the present inventor found that
A thermosetting resin as a main component and a thermoplastic resin as a subcomponent are dissolved or dispersed in an aqueous medium.
It has been found that extremely favorable results can be obtained by using an aqueous binder, and the present invention has been proposed.

As will be described in detail below, by using the Nono Ingu of the present invention, the usable life of the green mat can be greatly extended. Although it is not fully clear why such an effect is obtained, it is thought that it is due to the following mechanism.

In the present invention, an aqueous medium in which a thermosetting resin and a thermoplastic resin are dissolved or dispersed is used. These resins have a relatively low degree of polymerization, and when both resins are mixed homogeneously and the binder of the present invention is applied to short glass fibers and the water is evaporated, a film similar to the mixture of both resins is formed. It is formed. Both resins are mixed in extremely small amounts, and the thermoplastic resin is heated to high temperatures and partially melts or softens, so that the film formed by the binder is a thermosetting resin coated with the thermoplastic resin. It is composed of fine resin particles, which is thought to suppress the polymerization reaction of the thermosetting resin and extend the usable life.

By using the binder of the present invention, not only can the usable life of the raw mat be extended, but also the cured product obtained using the raw mat is soft to the touch.
It was found that it also has the unexpected effect of good restorability.

The reason why such an effect is obtained is considered to be approximately as follows. Since the surface of the short glass fibers constituting the cured product obtained using the binder of the present invention is coated with a soft thermoplastic resin, the short glass fibers are unlikely to break during handling or processing. Few. Therefore, short pieces are less likely to be cut due to breakage of short glass fibers during processing or handling of the cured product.

Short cut pieces mixed in cured products are a major cause of skin irritation, but when using the binder of the present invention, there are very few short cut pieces, resulting in a soft texture. It seems likely that it will be possible.

Although the reason is not clear, when the low-density heat insulating material obtained using the binder of the present invention is compressed and packed, the recovery rate is improved compared to when conventional bi-cedar is used. was completed.

Next, the present invention will be explained in more detail.

Thermosetting resins used for the binder in the present invention include phenol resin, melamine resin, and urea resin.
Resins such as modified resins or combinations thereof can be used, and these resins are used in the form of aqueous solutions or dispersions.

As the phenolic resin binder, a low polymer of formaldehyde and phenols such as phenol, cursol, xylenol, and resorcinol can be used. Low polymers of phenol and formaldehyde include those in various condensation stages, such as monomethylolphenol, thimethylolphenol, and trimethylolphenol.

As the melamine resin binder, a low polymer of melamine and formaldehyde can be used. A mixture obtained by polycondensing 1 to 6 moles of formaldehyde per 1 mole of ordinary melamine is used.

As the urea resin binder, a low polymer of urea and polardehyde can be used. A condensation reaction of 1 mole of ordinary urea and 13 to 2.0 moles of formaldehyde is used.

As the modified phenolic resin binder, a urea-modified phenolic resin binder obtained by adding urea and melamine during the condensation reaction process of phenol and formalin, and a melamine-modified phenol resin binder can be used. As the modified melamine resin binder, a urea-modified melamine resin binder obtained by adding urea during the condensation reaction process of melamine and formalin can be used.

Further, as the thermoplastic resin used for the binder in the present invention, vinyl acetate resin, acrylic resin, saturated polyester resin, etc. can be used.

As the vinyl acetate resin binder, polyvinyl acetate or epoxy-modified, acrylic-modified, I-lyester-modified, or urethane-modified versions thereof can be used, and these are used in the form of a dispersion.

As the acrylic resin binder, methyl polyacrylate, ethyl polyacrylate, and butyl polyacrylate can be used alone or in mixtures thereof, and methacrylic resin can also be used in the form of water-soluble or dispersion liquid. used.

As a sum/lyester binder, a condensation reaction product of a saturated dihydric alcohol such as ethylene glycol or zodz ester binder with a dibasic acid such as heptatalic acid, isophthalic acid, or succinic acid can be used. used in form.

In the present invention, a thermosetting resin is used as the main component of the binder, and a thermoplastic resin is used as a subcomponent.
A binder obtained by dissolving or dispersing these resins in an aqueous medium is added to short glass fibers immediately after being produced in a short glass fiber manufacturing apparatus. Short glass fiber mats are produced by pressurizing raw mats with a binder added in the next processing step.
Manufactured by heating.

The amount of binder added to the short glass fibers is preferably 2 to 15 inches in terms of solid content based on the weight of the short glass fibers.

The weight ratio of thermoplastic resin and thermosetting resin contained in the binder is 1:3 to 90. Desirably, the ratio is 1:5 to 20. If the weight ratio of thermoplastic resin and thermosetting resin is less than 3, the mold release property from the matte mold will be poor,
Moreover, the heat resistance temperature of the obtained product decreases. When the weight ratio is 90 or more, the usable life of the green mat is short, and the obtained product has no flexibility, and the restorability of the product is reduced when it is compressed and packed.

The raw mat using the binder of the present invention has a higher level of improvement than the raw mat using the conventional binder made only of thermosetting resin.
The usable life is several times longer, and the products obtained by processing the raw mat of the present invention have excellent resilience when compressed and packed compared to conventional products, and also have increased flexibility. Since it is hard to break, when used as a heat insulating material for automobiles with complex shapes, it can be assembled into automobiles extremely easily.

``Next, examples of the present invention will be shown.

Example 1 A binder solution with a concentration of 18% prepared in a solid content ratio of 85% by weight of the phenolic resin binder and 15% by weight of the acrylic resin binder was applied as a solid content of 8% to the short glass fibers immediately after loading. The mat was manufactured. This raw mat 5
After 30 days, 10 days, 20 days, 30 days, and 35 days, a pair of molds was used to press and heat at 230° C. for 3 minutes to produce short glass wire mats with a thickness of 20 y1 and a density of 48 kVrns.

No delamination was observed in mats formed after 5 to 30 days.

For mats molded after 35 days,
Although slight delamination was observed, there was no practical problem.

Separately, using a raw mat that has passed the above number of days, the thickness is 60 mm.
A short glass fiber mat with a density of 16% and a density of 16% was produced.

These mats were cut to a size of 30 α angle, and the top and bottom surfaces of the mats were sandwiched between thin plastic plates and compressed for 24 hours to a pure thickness.The top plastic thin plates were removed, and after 10 minutes, each mat was cut into pieces. The restored thickness was measured.・5 days,
The mats formed after 10 days, 20 days, 30 days, and 35 days were labeled A1, B1, C1, Dl, and El, respectively.
Then, the restored thickness is as follows.

Comparative Example 1 A green mat was produced by applying a binder solution with a concentration of 18%, which was prepared to have a solid content ratio of 100% by weight of phenolic resin, to short glass fibers immediately after production as a solid content of 8%. After allowing this raw mat to pass for 5 days, 7 days, and 10 days, Example 1
Glass fiber mats with a thickness of 20% and a density of 48% were produced under the same conditions as above. No delamination was observed in the mats molded after 5 or 7 days, but delamination was observed in the mats molded after 10 days.

Separately, using a raw mat that has passed the above number of days, the thickness is 60 mm.
Short glass fiber mats with a density of ~x6%/m were produced. The restored thickness of these mats was measured under the same conditions as in Example 1. After 5 days, 7 days, and 10 days, the mats were molded. If the mats are a1, bl, and cl, respectively,
The restored thickness was as follows.

Example 2 A binder solution with a concentration of 18%, which had a solid content ratio of 2% by weight of phenolic resin binder, 18% by weight of melamine resin binder, and 10% by weight of vinyl acetate resin binder, was hardened onto short glass fibers immediately after production. A raw mat was produced by applying 10 pieces per mold. Use this raw mat for 5 days, 10 days,
After 20 days, 25 days, and 30 days had elapsed, short glass fiber mats with a thickness of 20% and a density of 48% were produced by pressing and heating for 220,003 minutes using a pair of molds for 5 to 25 days. For the mats that were molded after 30 days had passed, no peeling between the eyebrows was observed.Also, for the mats that were molded after 30 days had passed, slight peeling between the eyebrows was observed, but there was no practical problem.

Separately, using a raw mat that has passed the above number of days, the thickness is 60 mm.
A short glass fiber mat with a density of 1% and a density of 15k5s was produced. The restored thickness of these mats was measured under the same conditions as in Example 1. After 5, 10, 20, 25, and 30 days, the molded mats were heated to
Assuming B2 r C2 * Dt * Et, the restored thickness was as follows.

Comparative Example 2 A No. 9 Ingu solution with a solid content of 801% by weight of phenol resin and 20 parts of melamine resin was applied to glass short fibers immediately after production to give a solid content of 10 parts. The mat was manufactured. Use this raw mat for 5 days, 7 days, 10 days.
After a period of time, the thickness was 20rr under the same conditions as in Example 2.
A glass fiber mat with a /m1 density of 46 kg/ms was produced. Mats molded after 5 to 7 days showed no glabellar peeling, but mats molded after 10 days showed delamination.

Using a raw mat that has been used for the above number of days, the thickness is 60 mm.
-1 Short glass fiber mats with a density of 16''V=s were produced.

The restored thickness of these mats was measured under the same conditions as in Example 1. Assuming that the mats formed after 5 days, 7 days, and 10 days were respectively a2°b2*c2, their restored thicknesses were as follows.

Claims (2)

[Claims] (1) A binder for short glass fibers, characterized in that a thermosetting resin as a main component and a thermoplastic resin as a subcomponent are dissolved or dispersed in an aqueous medium. (2) A short glass fiber mat characterized in that a binder made by dissolving or dispersing a thermosetting resin as a main component and a thermoplastic resin as a subcomponent in a water column medium is added to short glass fibers. Production method.