WO2005040276A1

WO2005040276A1 - Phenolic resin molding material and molded article thereof

Info

Publication number: WO2005040276A1
Application number: PCT/JP2003/013816
Authority: WO
Inventors: Shigehiro Kitaya; Nobuyuki Kawamura; Hideki Kawakita; Masanori Miyoshi; Yuya Kitagawa
Original assignee: Matsushita Electric Works, Ltd.
Priority date: 2003-10-29
Filing date: 2003-10-29
Publication date: 2005-05-06
Also published as: AU2003280584A1; JPWO2005040276A1; JP4874649B2

Abstract

A phenolic resin molding material comprising one or more phenolic novolaks and a filler, characterized in that at least part of the phenolic novolaks is a phenolic novolak modified with polyvinyl acetate; and a molded article obtained from the molding material.

Description

Description Phenol resin molding materials and molded articles

The present invention relates to a phenolic resin molding material used for producing heat-resistant parts such as a commutator of a motor for an automobile electric motor, and a molded article obtained therefrom.

Background art

Hitherto, phenolic resin molding materials have been used for commutators of motors for automobile electrical components or structural components around them due to their excellent moldability and excellent heat resistance and strength obtained by molding and hardening.

Recently, there has been a demand for further reduction of abnormal noise, that is, silent noise, in motor parts, particularly motor electric parts for automobiles, for example, in commutators of motors. One of the causes of this motor commutation noise is dimensional changes caused by mechanical or thermal loads.

Specifically, the mechanical and thermal loads in the commutator failing process performed after the molding from the phenolic resin molding material or the hyging process performed in the commutator mounting process, or the heat generated by the motor itself when the motor is driven. The heat generated by the engine of a car causes a dimensional change in the commutator.

If the dimensional change of the commutator is large, the roundness of the commutator is greatly degraded, and a large step occurs between the copper segments of the commutator. As a result, a loud noise is generated when the motor is driven.

In this regard, the phenol tree lumber molding material used for manufacturing commutators in the prior art cannot meet the demand for noise reduction because of large dimensional changes with respect to mechanical or thermal loads. .

Therefore, there is a need for a phenolic resin molded material that has a small dimensional change due to mechanical or thermal load. Disclosure of the invention

An object of the present invention is to provide a phenolic resin molding material having a small dimensional change with respect to a mechanical or thermal load, and a molded article obtained therefrom. .

A phenolic resin molding material comprising a novolak-type phenolic resin and a filler, wherein at least a part of the nopolak-type phenolic resin is a polyvinyl acetate-modified nopolak-type phenolic resin. , The dimensional change to mechanical or thermal loading was found to be small.

The polyvinyl acetate-modified novolak phenolic resin in the present invention is a modified nopolak-type phenolic resin produced using polyvinyl acetate in a synthesis step from phenol and formaldehyde, particularly phenol and formaldehyde in the presence of polyvinyl acetate. Means a modified novolak-type phenolic resin produced by dehydration-condensation. '

The step between the commutator copper segments and the deterioration of the roundness of the commutator caused in the environment where a mechanical or thermal load is applied are reduced by manufacturing the commutator using the phenolic resin molding material of the present invention. And can be prevented. As a result, it is possible to satisfy the demand for noise reduction in the commutator.

BEST MODE FOR CARRYING OUT THE INVENTION

The phenolic resin molding material of the present invention is characterized by containing a novolac type phenolic resin modified with polyvinyl acetate.

The polyacetate-modified novolak-type phenol resin can be produced as follows:

The nopolak type phenolic resin is usually produced by performing an addition reaction of phenol and formanolaldehyde in water in the presence of an acid catalyst, followed by dehydration condensation.

The polyacetate-vinyl-modified novolak phenolic resin of the present invention is produced by adding polyacetate to a reaction mixture formed from phenol and formaldehyde before the dehydration condensation in the production of the nopolak-type phenolic resin. The addition of poly (vinyl acetate) is added before and after the addition reaction between phenol and formaldehyde. Can be done in between. However, in order to avoid the inhibition of the addition reaction between phenol and formaldehyde by the polyacetate, it is preferable to add the polyacetate after the addition reaction and before the dehydration condensation.

The addition of phenol and formaldehyde is usually carried out in water in the presence of an acid catalyst.

Examples of such acid catalysts are p-toluenesulfonic acid, hydrochloric acid, formic acid, phthalic anhydride, boric acid and oxalic acid, preferably oxalic acid. .

Formaldehyde is usually used in the form of an aqueous formalin solution. Formaldehyde concentration in formalin aqueous solution is usually 3 7-5 0% by weight, preferably instrument 4 0-5 0 weight ^_0/0.

The addition reaction between phenol and formaldehyde is carried out usually at 80 to 120 ° C, preferably 90 to 110 ° C, for usually 1 to 4 hours, preferably for 2 to 3 hours. After the addition reaction, dehydration and condensation of phenol and formaldehyde (dehydration and condensation of phenol and formaldehyde adducts) are performed in the presence of polyvinyl acetate. The dehydration condensation is carried out at a temperature of usually 130-180 ° C., preferably 150-170 ° C., and usually 50-: L 0 0 kPa, preferably 60-7. It is carried out under a pressure of 5 kP'a, usually for 1 to 5 hours, preferably for 2 to 3 hours.

Polyvinyl acetate Biel-modified novolac-type Fueno one Honoré resin of the present invention, based on the weight of polyvinyl acetate Bulle modified Noporakku type phenolic resin, of 6 0-7 5 wt% Fueno le, 1 5 to 2 0 mass ^_0/0 formaldehyde, 0.2 0 to 0.2 5 weight ^_0/0 using a polyvinyl acetate Bulle of oxalic acid and 5-2 0 weight ^_0/0, preferably to produce.

In particular, it is preferable that the ratio of poly (vinyl acetate) in the poly (vinyl acetate) -modified novolak type phenol resin is 5% by mass or more. This is because the dimensional change of the phenolic resin molding material with respect to mechanical and thermal loads can be more effectively reduced by setting the polyacetic acid butyl compounding ratio to 5% by mass or more. On the other hand, as the blending ratio of polyacetate in the polyacetate-modified nopolak-type phenolic resin increases, the curing rate of the phenolic resin molding material containing the polyacetate-modified nopolak-type phenolic resin decreases. Therefore, in order to secure the desired curing rate, the polyacetic acid in the polyacetic acid-modified novolak type phenol resin The vinyl compounding ratio is preferably 20% by mass or less.

In order to obtain a polyacetate-modified vinyl acetate novolak phenol resin having good water resistance and chemical resistance, it is preferable to use a polyacetate biale having a weight average molecular weight of 1000 or more.

In addition, at the stage of producing the polyvinyl acetate-modified nopolak phenol resin, in order to ensure good dispersibility of the polyvinyl acetate in the reaction mixture, the polyvinyl acetate modified with a molecular weight of 100 Q It is preferred to use.

The polyacetic acid-modified nopolak type phenol resin produced as described above preferably has a weight average molecular weight of 2000 to 600. The polyvinyl sulphate-modified nopolak type phenolic resin having a weight average molecular weight in this range has a melt viscosity suitable for kneading and the like in the subsequent production of a phenolic resin molding material. '' '.' · '' ':

When the phenol resin molding material of the present invention contains an unmodified nopolak phenol resin, the nopolak phenol resin preferably has a weight-average molecular weight of 2000 to 400.

The polyphenol-modified nopolak-type phenol resin is usually taken out in a vat at a high temperature after its production, cooled and solidified, and then used for the production of a phenol resin molding material. In order to improve the subsequent handleability, it is preferable to pulverize the cooled and solidified polyvinyl acetate novolak type phenol resin.

Phenolic resin molding material of the present invention, preferably, based on the weight of the phenolic resin molding material, 1 0-3 0% by weight of polyvinyl acetate Bulle modified Noporakku type phenolic resins, novolac type 5-2 0 weight ^_0/0 phenol榭脂, 4 0 - including 6 0 mass ^_0/0 glass fibers and 5-2 0% by weight of an inorganic filler.

By kneading and pulverizing these mixtures using, for example, a twin-screw opening, the phenolic resin molding material of the present invention can be produced.

In particular, the compounding ratio of the polyacetic acid-modified nopolak type phenol resin in the phenol resin molding material is preferably 10% by mass or more. This is because the dimensional change of the phenolic resin molding material can be reduced more effectively by setting the compounding ratio of the polyacetic acid butyl modified nopolak phenolic resin to 10% by mass or more. Because it can.

On the other hand, as the compounding ratio of the polyacetate-modified novolak type phenol resin increases, the curing rate of the phenol resin molding material decreases. Therefore, in order to secure a desired curing rate, the blending ratio of the modified nopolak type phenol resin is preferably 30% by mass / ₀ or less.

A commutator having good strength can be obtained from a phenol resin molding material containing 40% by mass or more of glass fibers. On the other hand, in order to ensure a suitable melt viscosity when manufacturing the phenolic resin molding material itself or when molding a molded article from the phenolic resin molding material, the glass weight is preferably 60% by mass or less. . Examples of inorganic fillers included in the phenolic resin molding material include, but are not limited to, wollastonite, calcium carbonate, talc, mushylin and my mushy. These inorganic fillers can be used alone or in combination. .

By molding the phenolic resin molding material of the present invention; a commutator having a small dimensional change with respect to mechanical and thermal loads can be obtained. ·

Therefore, the present invention also provides a commutator obtained by molding the phenolic resin molding material of the present invention.

Examples of the method for molding the phenolic resin molding material of the present invention include, but are not limited to, injection molding, transfer molding, and compression molding. When molding the commutator, a curing agent is used to harden the phenolic resin molding material of the present invention containing a nopolak-type phenolic resin as a component. Hexamethylenetetramine is preferred as the curing agent. Hexamethylenetetramine is more preferably a granular hexamethylenetetramine, particularly a fine-particle hexamethylenetetramine containing at least 99% by mass of particles passing through an 80-mesh sieve, particularly a 150-mesh sieve. Hexamethylenetetramine in the form of fine particles containing 98% by mass or more of particles passing through is used. By using such a granular or fine particle of hexamethylenetetramine, uniform dispersion thereof is ensured, and the appearance of a molded article can be improved, and variations in moldability and physical properties can be suppressed.

Also, when forming the commutator, if necessary, the phenol resin composition of the present invention may be used. Additives or auxiliaries such as coupling agents, mold release agents, lubricants, dyes and pigments can be used with the form material.

Example

1. Manufacture of poly (vinyl acetate) -modified nopolak phenolic resin

Based on the total mass of the nopolak type phenolic resin modified with polybutyl acetate, 3

Prepared using 225% by weight of polyacetate butyl as follows:

First, phenol and formalin (about 50% aqueous solution) are reacted at 100 ° C for 90 minutes in the presence of oxalic acid, and emulsified at 100 ° C for 120 minutes. Acid beer (weight-average molecular weight: 1500) was added to the reaction mixture, dehydration-condensed at 160 ° C and 70 kPa for 180 minutes, and a polyvinyl acetate-modified novolak phenolic resin was added. To manufacture. It is taken out at a high temperature, 7 solidified, and pulverized and used for the production of the following molding materials. :. ———

2. Production of molding materials

The raw materials in the amounts shown in parts by mass in the following table were mixed for 1 minute, and the mixture was heated at a product temperature of 100 using a twin-screw kneader. Knead with C ~ 110 for 3 minutes. This kneaded material is pulverized after solidification by rejection, and the granulated molding material is used for forming test pieces for evaluating dimensional changes and the like.

The raw materials listed in the table are:

• Modified phenol resin: Polyvinyl acetate-modified novolak phenol resin produced as described above, with a weight average molecular weight of 300. Ratio described in Table (mass. / ₀₎ were used for the production of polyvinyl acetate Bulle modified novolac-type phenolic resin, shows the ratio of polyvinyl acetate Biel.

■ Phenol resin: Novolak type phenol resin, BRP590P manufactured by Showa Kogyo Co., Ltd.

'Glass ¾ 锥: Nitto Boseki Co., Ltd. CS 3 E—4 79 S, average fiber diameter ψ12, length 3 mm ₀

• Inorganic filler: NY CO 400 wollastonite NYAD 400.

• Additive: Hardener Hexamethylenetetramine (Particulate form, passing through an 80-mesh sieve, particle content of 99% by mass or more, passing through a 150-mesh sieve Particle content 98 mass. /. (7 parts by mass), Carnava lubricant (1 part by mass) (Carnava F-1 manufactured by Dainichi Kagaku 'Industries Co., Ltd.) and Dye Solvent Black (1 part by mass) (SAP-L manufactured by Orient Chemical Co., Ltd.) .

In order to examine the moldability of this molding material, 40 g of molding material was used. Extrusion flow tests [JIS K 6911] were performed at C and 29.4 MPa, and the outflow times were measured. The results are shown in the table below. The molding material preferably has an outflow time of 60 to 80 seconds from the viewpoint of practical molding.

3.Formation of test specimen for evaluation

The above molding material is formed by extrusion molding using a test piece mold with a JIS bending test shape at a mold temperature of 170 ° C, a curing time of 90 seconds, and an injection pressure of 128 MPa, and shrinks. Manufacture test specimens having JIS standard shape for test bending test. The following evaluation is performed on these test pieces.

4.Evaluation of test piece

The following evaluation was performed about the test piece. The results are shown in the table below. • Dimensional change due to annealing treatment

The test piece is annealed at 180 ° C. for 3 hours and then at 210 ° C. for 7 hours, and the dimensional change of the test piece due to the annealing treatment is measured. The specimen preferably has a small absolute dimensional change rate.

• Dimensional change due to high temperature treatment

The annealed test piece is further subjected to a high-temperature treatment at 200 ° C. for 500 hours, and the dimensional change of the test piece due to the high-temperature treatment is measured. The specimen preferably has a small absolute dimensional change rate. The bending strength of the test piece [JIS K 6911] was measured. The test piece preferably has a bending strength of 15 OMPa or more. (table 1 )

Example 1 Example 2 Example 3 Example 4 Example 5 Modified 3% by mass 1---1 phenol 5% by mass ° /. -11-11 mass% resin--15 10-

15% by mass 12 18

20 mass ^_0/0 one - - A -

25% by mass

Phenol tree B

Says 19 13 16 20 16 Polyvinyl acetate

Force, lath fiber 48 48 45 45 50 Inorganic filler. 12 12 '15 15 10 Additive 9 9 9 9 9 Flow time (sec) 75 68 65 69 78 . 02 -0. 04 0.10 Dimensional change rate (%)

High temperature treatment-0.18-0.14-0.22-0.24 -0.15 Dimensional change (%)

Flexural strength (MPa) 178 185 164 172 188

(Table 2)

Example 6 Example 7 Example 8 Example 9 Example 10 Modification.18

Phenol 10

Resin 10% by mass

15 mass ^_0/0 5

20 mass ^_0/0 18

25 mass ^_0/0 18

Phenolic resin 20 13 13 13 25 e. Rishang acid arsenic, 'nil

Force, lath fiber 45 48 45 50 45 Inorganic filler 15 12 15 10 15 Additive 9 9 9 9 9 Flow time (sec) 77 56 54 44 70 By aniline treatment-0.06 0.10 -0. 12 0. 10 -0. 11 Dimensional change rate (%)

High temperature treatment-0.25 -0.12-0.28-0.25-0.29 Dimensional change rate (%)

Flexural strength (MPa) 191 171 157 191 167 (Table 3)

Example 11 Example 12 Comparative Example 1 Comparative Example 2 denatured single - A one Fueno, Les 5 wt% one 18 one first resin 10 mass ^_0/0 eleven eleven

15% by mass 31 ― one ―

20 mass ^_0/0 one hundred eleven -

25% by mass

Phenol tree B g

Says 13 30 28 e. Liquorate acid 3 power, lath Note 48 37 48 48 Inorganic filler 12 23 12 12 Additive 9 9 9 9 Flow time (sec) 42 71 68 66 0.17 -0.15 Dimensional change rate (%)

By high temperature treatment-0.16-0.15 -0.35 -0, 33 Dimensional change rate (

Flexural strength (MPa) 166 127 169 172

Claims

The scope of the claims

1. A phenolic resin molding material containing a nopolak-type phenolic resin and a filler, wherein at least a part of the novolak-type phenolic resin is a polyvinyl acetate-modified nopolak-type phenolic resin. , Fenoll Jujube molding material. .

2. Polyvinyl acetate Bulle modified Noporakku type phenolic trees month effect, characterized in that the mass of polyvinyl acetate modified Bruno Pollack type phenolic resin produced had use of polyvinyl acetate Bulle of 5-2 0 weight ^_0/0 to the reference The phenolic resin molding material according to claim 1.

3. The polyvinyl acetate Bininore modified Noporakku type phenolic resin, based on the weight of polyvinyl acetate modified novolac type Fueno Le resin, 6 0-7 5 mass ^_0/0 of phenol, 1 5, 2 0% by weight of formaldehyde The phenolic resin according to claim 1 or 2, characterized in that the phenolic resin is manufactured using 0.20 to 0.25% by mass of oxalic acid and 5 to 20% by mass of polyacetic acid butyl. Molding material. .

4. The poly (vinyl acetate) -modified nopolak phenolic resin is produced using poly (vinyl acetate) having a weight-average molecular weight of 100,000 to 1,000,000. A phenolic resin molding material according to any one of the above.

5. The phenolic resin molding material according to any one of claims 1 to 4, comprising a polyvinyl acetate-modified nopolak phenolic resin having a weight-average molecular weight of 2000 to 600.

6. The phenol according to any one of claims 1 to 5, comprising 10 to 30% by mass of a phenolic resin-modified novolak type phenolic resin based on the mass of the phenolic resin molding material. Resin molding material.

7. 10 to 30 masses ⁰ / based on the mass of the phenolic resin molding material. Polyvinyl acetate Bie Le-modified novolac-type phenolic resin, 5-2 0 weight ^_0/0 novolak phenolic resins, 4 0 - 6 0 mass ^_0/0 Glass fiber and 5-2 0 weight ^_0/0 of inorganic filler The phenolic resin molding material according to any one of claims 1 to 6, further comprising:

8. A commutator obtained by molding the phenolic resin molding material according to any one of claims 1 to 7.