DE2235197C3 - Laminate - Google Patents

Description

The invention relates to a laminate that consists of several layers of a substrate impregnated with a resin by pressing while heating was formed with curing of the resin.

Such laminates are known. They are made by impregnating a carrier material, for example Paper, cloth, cloth or glass fibers, with thermosetting resins, for example unsaturated ones Polyester resins, phenolic resins, melamine resins, epoxy resins and diallyl phthalate resins are made, whereupon laminates are produced from these carrier materials. These laminates are missing however, processing properties in the production of holes. Especially when the perforation at room temperature, e.g. B. in the range of 10 to 30 ° C occurred, damage such as cracking, bulging and chipping was easily made on the Surface or in the Lochteii or edge part caused, so that these laminates are practically not without could be used further.

Plasticizers or plasticizers or the resins themselves have already been added to the resins chemically modified in order to eliminate the disadvantages outlined above. These ways of working are but associated with the following disadvantages:

(1) Properties such as electrical insulation, water resistance, chemical resistance, heat resistance and mechanical strength have deteriorated,

(2) Substances used for plasticization sometimes came out of the surface of the laminates off and

(3) Intermediate products that are temporarily stored and made by impregnating the carrier material with the resins were made; d. H. so-called "prepregs" were sticky because of the softening point the resins were lowered.

Since plasticizers, which are liquid at room temperature, are added to the resins or substances, which cause the crosslink density of the resins to deteriorate, into the resins may be introduced, a lowering of the softening point of the resins and a deterioration the water resistance, chemical resistance, mechanical strength and electrical properties cannot be avoided.

Plasticizers are also known which are solid at room temperature. However, practical own all of these plasticizers have poor electrical properties or poor water resistance and chemical. Persistence, or they are organic materials, which adversely affect the curing properties of the resin. Hence are the properties of the laminates obtained deteriorate.

It is also known to add titanium dioxide to synthetic resins - also in laminates - and ίο as a white pigment, especially in the surface of bodies made from the resin. It is also known that by adding fillers or the same properties of synthetic resin bodies affect can.

The invention is based on the object of creating a laminate of the type mentioned above, which has good processing properties for hole and punching processing, especially at room temperature, without impairing the electrical properties and resistance to chemical, mechanical and temperature-related loads. According to the invention, this object is achieved by using up to 25% by weight (based on the weight of the resin) of titanium dioxide as a filler in the cured resin of all layers as the sole means of improving the hole and punching properties of the laminate in the laminate described above will.
It was surprisingly found that the processing properties during perforation or punching are improved by adding only titanium dioxide, which is an inorganic substance and is solid and even hard at room temperature. On the basis of studies with calcium oxide, magnesium oxide, aluminum oxide, tin oxide, antimion trioxide, lead oxide, zinc oxide, silicon dioxide, calcium carbonate, chlorinated paraffins, tetrabromophthalic anhydride and tetrabromobisphenol A, it was found that the effect of improving the processing properties during perforation or punching is a characteristic property only Titanium dioxide alone is. This is surprising because the titanium dioxide is an inorganic compound and it could not be assumed that it has a softening effect. Above all, it is surprising that the plasticizing effect is also developed when a carrier material of great rigidity, such as one made of glass fibers, is used.
Titanium dioxide is an inorganic substance and a powder at room temperature; its use therefore has no adverse effect on the electrical properties or on the softening point, water resistance, chemical resistance and mechanical strength of the resins.

The production of the laminate does not cause high costs either, since titanium dioxide can be added at any stage in the process.

However, it is preferably dispersed in a resin solution. The laminate can then as before can be produced by adding a carrier material, for example paper, fabric or fiberglass cloth, to this resin solution immersed or otherwise impregnated with this, dried and prepregs obtained from these through Pressing and heating the laminates are formed.

22nd

The laminate can also be in one form with resin, in which carrier webs are placed in a stack and this is heated while pressing, getting produced.

A suitable particle size range of the titanium dioxide is less than about 50 μm, preferably less than ΙΟμίη.

If the titanium dioxide is added in an amount greater than 0.2% based on the weight of the resin, the effect can be seen. However, it is preferred to use the titanium dioxide in an amount greater than 1%, based on the weight of the resin, add. The upper limit of the amount of titanium dioxide is 25% based on weight of the resin, it is given also taking into account the fact that if the titanium dioxide is used in an amount above this limit, the resin solution has too high a viscosity attained and the impregnation of the carrier material is difficult to carry out because the titanium dioxide precipitates. A preferred range is 2 to 20% by weight.

The addition of titanium dioxide to the resin occurs 197

using a disperser such as a homogenizer, a colloid mill, or a 3-roller mixer. The addition of titanium dioxide takes place in addition to the usual ones Fillers, such as calcium carbonate, silica, Magnesium oxide, tin (II) oxide, tin (IV) orjd, Aluminum oxide, lead oxide, zinc oxide, antimony oxide, tetrabromobisphenol A, antimony trioxide, chlorinated Paraffin and tetrabromophthalic anhydride, which are found in Quantities of up to 20% by weight, based on the resin, are added.

For example, the following table shows synthetic resins indicated, which are used in the production of the prepregs; furthermore, the quantities of the Carrier material to be impregnated resins, the drying temperatures and the heating and pressing conditions in preparing the laminates listed. All percentages given here relate to weight, unless otherwise specified.

Phenolic resin

Epoxy resin melamine resin

Unsaturated
Polyester resin

Type of solvent

Amount of solvent *)

Impregnation amount of the
Resin in the carrier material **)

Drying temperature

Drying time

Form printing

Mold temperature

Forming time

Methanol, toluene

generally 30-110% preferably 50-100% generally 35-65% preferably 45-55% 70-160 ⁰ C 5-30 min 30-150 kg / cm ² 120-180 ⁰ C 15-90 min

Methyl ethyl ketone,
acetone

generally
30-110%
preferred
50-100%
generally
30-60%
preferred
35-45%
70-160 ° C
5-30 min
30-150 kg / cm ²
120-180 ⁰ C
15-90 min

Methyl ethyl ketone

generally
30-110%
preferred
50-100%
generally
35-65%
preferred
45-55%
70-160 ⁰ C.
5-30 min
30-150 kg / cm ²
120-180 ° C
15-90 min

Methyl ethyl ketone,

Acetone, toluene,

Benzene, xylene,

Styrene

generally

40-70%

preferred

50-60%

generally

30-70%

preferred

40-60%

70-160 ° C

5-30 min

30-150 kg / cm ²

120-180 ° C

15-60 min

*) Based on the total of the crosslinking agent and resin. * ·) Based on the weight of the prepreg (dried).

Conventional nonwovens or fabrics made of glass fibers, natural and / or synthetic fibers are used.

The following examples illustrate the invention.

example 1

Phenol 1.0 mol

Formalin 1.2 moles (calculated as

Formaldehyde)

Ammonia 3 mol% (based on

the phenol) A composition obtained from the above mixture was reacted at 100 ^Q C for 90 minutes under reflux. After the completion of the reaction, the reaction mixture was heated under reduced pressure to dehydrate. Heating was continued until the temperature of the mixture was 100 ° C. 80% by weight of methanol, based on the phenol, were then added all at once, a phenolic resin solution (resin A) having a viscosity of 21OcP (25 ° C) and a specific

fi ₅ fish weight of 1.050 (25 ° C) was obtained.

Fne resin mixture in which titanium dioxide is homogeneous was dispensed, became of the following composition manufactured:

Parts by weight

HarzA 100

Methanol 2

Titanium dioxide 4

A carrier web made of paper (23 g / m ² ) was impregnated with this resin mixture and dried at 130 ° C. for 8 minutes to produce a prepreg with a resin content of 48%, based on the weight of the beepreg. The prepreg did not have any tackiness at room temperature. Eight sheets of this prepreg were stacked on top of one another, and a laminate sheet (1 j with a thickness of 1.6 mm was produced at a temperature of 155 ° C. and a pressure of 120 kg / cm ^{2 for 60 minutes. In the same way, a sheet (} II) containing no titanium dioxide, the properties of the obtained sheets (I) and (II) were determined, and the results obtained are shown in Table I.

Table I.

valuation Treatment conditions unit Laminate layer molding material train (I) train (H) 1.2 - 10 " Insulation resistance C-90/20/65 ¹ ) Ll 1.0 x 10 " 2.0 · 10 ⁸ i insulation resistance C-90/20/65 + D-2 / 10O ² ) il 2.4-10 ⁶ 12.5 Flexural strength A *) kg / mm ² 12.4 0.83 Water absorption D-24/23 ³ ) % 0.85 4.98 f C-90/20/65 ¹ ) 1 MH ₃ , - 4.52 5.11 C-90/20/65 + D-48/50 ⁴ ) I MH ₇ - 4.77 0.041 tango C-90/20/65 ¹ ) 1 MHz - 0.036 0.043 tang h C-90/20/65 + D-48/50 ⁴ ) 1 MH _Z - 0.038 0.140 Dimensional stability El / 150 ⁵ ) % 0.140 Hole ability (room temperature) A *) X Bulge around the holes - OO X Surface cracking - OO X Splinter formation on the edges - O

') C-90/20/65: 90 hours at 20 ^° C. under 60% humidity (JIS).

² ) D-2/100: additional immersion at 100 ° C for 2 hours in water.

³ ) D-24/23: immersion for 24 hours at 23 ° C. *) D-48/50: immersion for 48 hours at 50 ° C. ⁵ J El / 150: drying at 150 ° C for one hour, • j A: a state obtained without any treatment.

As can be seen from the results contained in Table I, the laminate sheet with the Titanium dioxide excellent processing properties for perforation. There was no change any of the other properties observed.

In Table I, the ratings of the processing properties performed on punching using ASTM method D-617, and the evaluation is shown symbolically, where "OO" is very good, "O" is good, "Δ" is average and "Χ" means bad. In the following examples as well, the same ratings and the same were given Assessments applied.

Example 2 Parts by weight

Epoxy resin 100

Dicyandiamide 5

Benzyldimethylamine 0.2

Parts by weight

Titanium dioxide powder, 1 μΐη 2

Dimethylformamide 10

A glass fiber fabric (202 g / m ² ) with a silane. j'-aminopropyltriethoxysilane, was impregnated with an epoxy resin mixture of the composition described above and dried at 130 ° C. for 10 minutes.

In this way, a prepreg was produced with a resin content of 36% based on the prepreg, which did not show any tackiness at room temperature. Nine sheets of this prepreg were stacked, and at a temperature of 160 ⁰ C and a pressure of 90 kg / CRRR for 60 min a Schichtpreßstoffbahn (III) was prepared with a thickness of 1.6 mm ·. A laminate sheet (IV) containing no titanium dioxide was produced in the same way. The properties of the layer sheet obtained in each case were determined, and the results are also given in Table.

Table lla

valuation

Conditions of sale

Flexural strength
Insulation resistance
Insulation resistance
Water absorption

tang ι) **)
tang Λ **)

Dimensional stability
Punchability (room temperature)
Bulge around the holes
Surface cracking
Splinter formation on the edges

A *)

C-90/20/65 ¹ )

C-90/20/65 D-2/100 ² )

D-24/23 ³ )

C-90/20/65 ¹ ) 1 MH ₂

C-90/20/65 D-48/50 *) 1 MH _Z

C-90/20/65 *)! MH _Z

C-90/20/65 D-48/50 *) I MH _Z

El / 150 ⁵ )

Ltnlien Laminate Layer- railway (Ill) molding material train (IV) kg / mm ² 53.8 53.2 η 6.8 · 10 ³ 6.7 · 10 ¹ Ll 7.4 x 10 ¹⁰ 7.5 · 10 ¹⁰ % 0.064 0.062 - 4.98 4.92 - 5.21 5.19 0.020 0.020 0.024 0.025 % 0.018 0.018 OO X OO X OO X

¹ ) C-90/20/65: 90 hours at 20 ° C under 60% humidity (JIS).

² ) D-2/100: additional immersion at 100 ° C for 2 hours in water

³ ) D-24/23: immersion for 24 hours at 23 ° C. *) D-48/50: immersion for 48 hours at 50 ⁰ C. ⁵⁾ El / 150: drying at 150 ° C for one hour. *) A: a preserved state without any treatment.

tang d "): dielectric constant.

You can also drill holes. The results obtained are shown in Table Hb below reproduced.

Table Mb Wall surface of the Panel of fabric (IV) 40000rpm Number of holes roughness of the 2-3 2.5 / 100mm / um
rotation Holes iy.m) Laminate laminate 8-15 0.9 mm train (III) 10-20 1000 2-3 20- ^ tO 5,000 2-8 The conditions when drilling were as follows: 10,000 5-10 drilling machine 15,000 8-15 number of revolutions Lowering speed ... Diameter of the drill

40

45

55

6o

As can be seen from the results shown in Table II a and Hb, the effect of titanium dioxide ⁵ on processing properties was excellent in making holes at normal temperatures.

Example 3

Maleic anhydride 1.8 moles

Phthalic anhydride 1.2 moles

Isophthalic acid 1.0 mole

Ethylene glycol 2.1 moles

Propylene glycol 2.0 moles

An unsaturated polyester resin with an acid number of 15.9 and a softening point of 65 ° C (Resin B) was prepared by reacting the above ingredients among those described in Example 5 below Conditions established. Using this resin B, a resin mixture became the following Composition made:

Weight

Resin B 70

Styrene 30

Benzoyl peroxide 2

Titanium dioxide powder 4

Calcium carbonate 16

900 g of this resin mixture were placed in a mold for the production of plates in which three strips of a mat made of synthetic fibers based on polyvinyl alcohol (160 g / m ² ) were stacked on top of one another. A laminate sheet (V) was produced at a temperature of 120 ^° C. and a pressure of 20 kg / cm ^{2 for 30 minutes.} A laminate sheet (VI) containing no titanium dioxide was produced in the same way. The results of the comparison are shown in Table III.

Table III

Table IV clearly gives those obtained with titanium dioxide Effect.

Layer-layer

Preßstoff- Preßstoffbahn (V) web (Vl)

Material by punching

processed

(Room temperature)

Bulge around the holes OO

Surface cracking OO

Chip formation at the edges OO

Δ Δ Δ

The effect obtained using the titanium dioxide can be seen clearly from the table in the table !!! reproduced Results.

Example 4

Melamine 126 g

Formalin 211g

Sodium carbonate 0.3 g

Water 30 g

50 g of acetoguanamine, 0.046 g of sodium hydroxide and 0.5 g of water after reaction of the above-described composition at 10O ⁰ C for 60 min was added. The mixture was ^{reacted at 80 °} C. for 60 min. 0.12 g of oxalic acid was added to this solution to produce a modified melamine resin with a solids content of 58%, based on the total mixture (resin C).

Resin C 470 g

Sulphonic acid imide type hardener .... 8 g
Titanium Dioxide Powder Ig

Lint paper for laminated sheets (122 g / m ² ) was impregnated with the above resin mixture and dried at 110 ° C. for 10 minutes to produce a prepreg which had no tackiness at normal temperatures (resin content: 46% based on the prepreg).

Eight webs of this prepreg were stacked on top of one another, and a laminate web (VII) with a thickness of 1.55 mm was produced ^{at a pressure of 100 kg / cm 2} and a temperature of 160 ^{° C. for 60 minutes.} A laminate sheet (VIII) containing no titanium dioxide was produced in the same way. The processing properties during punching at room temperature for both laminate sheets were determined, where-

kai Ata Hm _n U _n ^ n _n ^ - T *., t_ ~ 11 ~ Λ \ Τ T_J 1 _! 1

cw ut «. i ^ ig \, LMii3ac 111 IdUCIlC] V WlCUCIgCgCUCII MIIU.

Table IV Example 5

Layer- layer molding material molding material train (VII) train (VIII) Processing properties when punching (Room temperature) Bulge around the holes OO X Chip formation on the edges O X Surface cracking OO X

Maleic anhydride 2.0 moles

Phthalic anhydride 1.0 mole

ίο isophthalic acid 1.0 mol

Propylene glycol 4.15 moles

An unsaturated polyester resin with an acid number of 16.3 and a softening point of 66 to 68 "C (Resin D) was prepared by conventional reaction of the above ingredients (the conditions of Implementation are described below). Then the following ingredients were used to make a Resin mixture dissolved and suspended homogeneously.

Parts by weight

Resin D 72

Diallyl phthalate prepolymer 28

tert-butyl perbenzoate 1.5

Titanium dioxide powder 2

Toluene 50

Acetone 40

A glass fiber fabric (202 g / m ² , treated with silane according to Example 2) was impregnated with the above resin mixture and ^{dried at 120 °} C. for 10 minutes to produce a white prepreg which was not tacky at all at room temperature. This prepreg had a resin content of 43% based on the prepreg.

Nine sheets of this prepreg were superposed on each other in stacks, and at an E> and a temperature of 14O ⁷¹ C for 45 jerk of 30 kg / cm ² min, a Schichtpreßstoffbahn (IX) with a thickness of 1.6 mm was prepared. A laminate sheet (X) without titanium dioxide powder was produced in the same way.

The properties of the obtained laminated sheet (IX) and the laminated sheet (X) became determined, the results being given in Table V.

The conditions for producing the polyester were as follows:
Dibasic acids such as maleic anhydride and isophthalic acid and glycol components such as ethylene glycol and propylene glycol were placed in a four-necked flask equipped with a condenser and a thermometer, and an inert gas such as nitrogen and carbon monoxide were introduced therein. The mixture was slowly heated with stirring. When the temperature reached 140 to 180 ^° C., severe dehydration gradually set in. This dehydration reaction was carried out for about 5 to 10 minutes,

until the temperature reached a maximum of 200 to 230 ⁰ C while the acid number was determined. In this case, dehydration can be carried out under reduced pressure, if necessary. A precaution should be taken so that the

unreacted glycol component does not escape. After the acid number reached 15 to 35, that became obtained resin removed all at once by cooling. This resin was solid at room temperature.

S.
5
ρ 2235 197 12th X Ι π 42.1 Table V Laminate sheet 7.0 10 ¹² ϊ Evaluation unit IX 3.4 ■ 10 ¹² ί
» 42.5 0.12 j flexural strength kg / mm ² 6.2 · 10 ¹² 4.3 j Insulation resistance (C-90/20/65) ¹ ) U 3.5 · 10 ¹² 4.3 \ Insulation resistance (C-90/20/65 D-2 / lOOf) U 0.12 96 x 10 " ⁴ jj water absorption (D-24/23) ³ ) % 4.2 121 x 10 " ⁴ \ t (C-90/20/65) ¹ ) IMH ₇ . - 4.3 0.028 \ f (C-90/20/65 D-48/50 / *) 1 MH ₂ - 98 x 10 " ⁴ • tang Λ (C-90/20/65) ¹ ) 1 MH ₂ - 126 x 10 " ⁴ X \ tang ή (C-90/20/65 D-48 / 50J *) 1 MH ₂ - 0.012 X \ Dimensional stability (El / 150) ⁵ ) % X i punchability OO Bulge around the holes - OO Surface cracking - O Chip formation on the edges -

') C-90/20/65: for 90 hours at 20 ⁰ C with 60% humidity (JIS).

²⁾ D-2/100: additional dipping at 10O ⁰ C for 2 hours in water.

³ ) D-24/23: immersion for 24 hours at 23 ° C. *) D-48/50: immersion for 48 hours at 50 ° C. ⁵ ) El / 150: drying at 150 ^° C. for one hour.

tang ti * '): dielectric constant.

As can be seen from the results contained in Table V, the effect of titanium dioxide on the The ability to punch holes at room temperature is remarkable.

35

Example 6

Maleic anhydride 1 mole

Isophthalic acid 1 mole

Propylene glycol 2.15 moles

An unsaturated polyester resin with an acid number of 15.6 and a softening point of 73 to 76 ° C (Resin E) was obtained by reacting the above ingredients under the same conditions as in Example 5 described prepared. Then the following ingredients were mixed homogeneously:

Parts by weight

Resin E 85

Tris-carboallyloxymethyl isocyanurate .. 15
tert-butyl perbenzoate 1

Table VI Parts by weight

Titanium dioxide powder 3

Toluene 40

Acetone 50

A glass fiber fabric (310 g / m ² , treated with the silane according to Example 2) was impregnated with the above mixture and dried at 70 ° C. for 20 minutes and further at 120 ° C. for 10 minutes to obtain a prepreg which was at room temperature did not show any stickiness. This prepreg had a resin content of 55% by weight based on the prepreg. Then four sheets of the prepreg were stacked one on top of the other, and a laminate sheet (XI) with a thickness of 2.14 mm was produced ^{at a pressure of 35 kg / cm 2 and a temperature of 145 ° C.}

A laminate sheet (XII) was produced in the same way, but with tin (II) oxide instead of titanium dioxide powder was used. The results of the evaluation of the properties included in carried out in the same manner as described in Example 5 is shown in Table VI.

valuation

unit

Laminate sheet (XI)

Laminate sheet (XU)

Flexural strength kg / mm ²

Insulation resistance (C-90/20/65) ¹ ) Ω

Insulation resistance (C-90/20/65 D-2 / 10O) ² ) Ω

Water absorption (D-24/23) ³ )%

F (C-90/20/65) ¹ ) 1 MH ₂ -

_f (C-90/20/65 D-48/50) *) 1 MH ₂ -

') C-90/20/65: 90 hours at 20 ° C under 60% humidity (JIS).

² ) D-2/100: additional immersion at 100 ° C for 2 hours in water.

³ ) D-24/23: immerse for 24 hours at 23 "C.

⁴ ) D-48/50: immersion for 48 hours at 50 ° C.

⁵ ) El / 150: drying at 150 ° C. for one hour.

18.4 ΙΟ ¹³ 18.4 10 ¹³ 3.2 10 ¹⁰ 3.8 ΙΟ ¹⁰ 3.8 3.4- 0.12 0.12 3.54 3.68

3.78

3.82

continuation

Evaluation of the unit

tang Λ (C-90/20/65) ¹ ) 1 MH _z

tang Λ (C-90/20/65 D-48 / 50f) 1 MH _Z -

Perforation ability

Bulge around the holes -

Surface cracking -

Chip formation at the edges -

Dimensional stability%

') C-90/20/65: for 90 hours at 2O ⁰ C under 60% humidity (JIS). *) D-48/50: immersion for 48 hours at 50 ° C. ³ ) El / 150: drying at 150 ° C for one hour, tang O ⁺ : dielectric constant.

The effect of the titanium dioxide is clear from the results shown in Table VI.

Example 7

Maleic anhydride 4.5 moles

HET acid 5.5 moles

Propylene glycol 10.2 moles

An unsaturated polyester resin with an acid number of 21 and a softening point of 74 to 75 ° C (Resin F) was prepared from the above ingredients under the conditions described in Example 5.

Parts by weight 80

Laminated fabric sheet (Xl) Sehiehlpreß-
stolTbahn (XII] 118 x 10 ~ ⁴
148 · ΙΟ ' ⁴ 112 x 10 " ⁴
142 x 10 ~ ⁴ OO
OO
O
0.030 X
χ — Α
A.
0.032

contains.These laminate sheets pilin and fXIV) possessed self-flame-extinguishing properties, and their other properties were practically that same as those described in Example 5.

Resin F

Tris - carboallyloxymethyl isoeyanurate 20

tert-butyl perbenzoate 1

Titanium dioxide powder 10

Antimony oxide powder 4

(Particle size: 15-25 μm)

Toluene 85

The ingredients described above were mixed homogeneously. (211 g / m ^2, treated with silane according to Example 2) was impregnated glass cloth with the above mixture and min at 8O ⁰ C for 5 and then at! 15 ⁰ C for 10 minutes to obtain a prepreg impregnated, which at room temperature no Exhibited stickiness. Ten sheets of this prepreg were stacked on top of each other, and at a temperature of 140 ° C and

Example 8 Parts by weight

Resin E 94

Acrylamide 6

Titanium dioxide powder 5

tert-butyl perbenzoate 1.5

Acetone 80

Toluene 10

The ingredients described above were mixed homogeneously. A (with melamine resin treated paper melamine resin content: 9.6%, based on the paper weight, thickness 254 (im) was impregnated with the above mixture and min at 85 ° C for 5 and then at 11O ⁰ C for 15 dried min, wherein a Prepreg was produced with a resin content of 49.3% by weight, based on the prepreg, which did not show any tackiness at room temperature. Eight sheets of this prepreg were stacked on top of one another and at a pressure of 100 kg / cm ² and a temperature of 160 A laminate sheet (XV) with a thickness of 1.78 mm was produced for 40 hours at ^{0 ° C. A laminate sheet (XVI) was obtained in the same way, but with}

a pressure of 40 kg / cm ² for 60 minutes, zinc oxide was used in place of the titanium dioxide powder

a laminate sheet (XIII) with a thickness. The results of the assessment of the

made of 1.8 mm. In the same way, shafts made in the same manner as in Example 1

a laminate sheet (XIV) described using are determined in Table VII

made of a resin mixture that does not reproduce titanium dioxide.

Table VII

valuation

unit

Laminate sheet (XV)

Laminate sheet (XVI)

Flexural strength

Insulation resistance (C-90/20/65) ¹ ) Insulation resistance (C-90/20/65 D-2/100) ² )

¹ ) C-90/20/65: 90 hours at 20 ° C under 60% humidity (JIS). ) D-2/100: additional immersion at 100 ° C. for 2 hours in water.

kg / mm ²

Ω.

18.6

4.6 ¹³
3.9 - ΙΟ ⁹

18.4

4.1 ■ ΙΟ ¹³
9.4 · 10 ⁹

continuation

valuation

unit

Water absorption%

f (C-90/20/650) ¹ ) 1 MH ₂ -

y (C-90/20/65 D-48 / 50f) 1 MH _Z -

Dimensional stability (E-1 / 15Of) % perforation capacity

Bulge around the holes -

Surface cracking -

Chip formation at the edges -

¹ ) C-90/20/65: 90 hours at 20 ° C under 60% humidity (JIS). *) D-48/50: immerse for 48 hours at SO ⁰ C.
⁵ ) E-1 / I50: drying at 150 ° C. for one hour.

SchicrilpreßstoUbahn (XV)

0.23

4.25
4.76
0.07

O
O
O

Laminate train (XVI)

0.29
4.30
4.72
0.08

Δ
χ

As can be seen from the results of Table VIl, the sheet using titanium dioxide had excellent perforation properties Room temperature.

Example 9

Parts by weight

Diallyl phthalate preporymeres 100

Acetone 50

Methyl ethyl ketone 50

tert-butyl perbenzoal 1.5

Titanium Dioxide Powder 1

A resin mixture was prepared by dissolving and homogeneously dispersing the above ingredients. A glass fiber fabric (210 g / m ² ) was impregnated with the resin and dried to obtain a prepreg having a resin content of 46.2% and a volatile matter content of 0.29% based on the prepreg.

A laminate sheet was made by stacking eight sheets of this prepreg and treated according to the procedure described in Example 5.

When the perforation was carried out, this laminate sheet showed a very good result (the assessment, as described in example 1, was "OO"). The following is an example of a Process for the preparation of the diallyl phthalate prepolymer described.

Weight parti

Diallyl phthalal monomer 100

Water 50

Benzoyl peroxide 1

Dibutyltine dilaurate I.

The above mixture was heated to 85 ° C for 4 to 5 hours in a flask with stirring implemented. After cooling, an aqueous layer separated off. To the polymer solution obtained methanol was added in an amount of 10 times the volume with vigorous stirring. The stirrer was continued until the polymer mixture was completely brought into contact with the methanol wherein a diallyl phthalate prepolymer was precipitated as a solid. This was filtered off and divided Preparation of a white powder of the diallyl phthalate prepolymer dried. This diallyl phthalate prep polymers had a saponification number of 406 and a lod number of 56.

909 648/11

Claims (1)

Claim: Use of up to 25% by weight (based on the weight of the resin) of titanium dioxide as a filler in the hardened resin of all layers of a laminate made up of several layers a carrier material impregnated with the resin by pressing while heating while curing of the resin as the sole means of improving its piercing and punching properties.